0001326732-26-000015 | 10-K | XBRL Viewer

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Fair Value Measurement (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Fair Value of Financial Instruments
Marketable debt securities	$ 556,760
Marketable equity securities	112,502	$ 47,929
Total Fair Value	704,827	739,913
Corporate securities
Fair Value of Financial Instruments
Marketable debt securities	11,968	142,873
Government securities
Fair Value of Financial Instruments
Marketable debt securities	544,792	522,931
Level 1
Fair Value of Financial Instruments
Marketable equity securities	112,502	47,929
Total Fair Value	148,067	74,109
Level 1 \| Corporate securities
Fair Value of Financial Instruments
Marketable debt securities	0	0
Level 1 \| Government securities
Fair Value of Financial Instruments
Marketable debt securities	0	0
Level 2
Fair Value of Financial Instruments
Marketable equity securities	0	0
Total Fair Value	556,760	665,804
Level 2 \| Corporate securities
Fair Value of Financial Instruments
Marketable debt securities	11,968	142,873
Level 2 \| Government securities
Fair Value of Financial Instruments
Marketable debt securities	544,792	522,931
Level 3
Fair Value of Financial Instruments
Marketable equity securities	0	0
Total Fair Value	0	0
Level 3 \| Corporate securities
Fair Value of Financial Instruments
Marketable debt securities	0	0
Level 3 \| Government securities
Fair Value of Financial Instruments
Marketable debt securities	0	0
Money market funds
Fair Value of Financial Instruments
Cash equivalents:	35,565	26,180
Money market funds \| Level 1
Fair Value of Financial Instruments
Cash equivalents:	35,565	26,180
Money market funds \| Level 2
Fair Value of Financial Instruments
Cash equivalents:	0	0
Money market funds \| Level 3
Fair Value of Financial Instruments
Cash equivalents:	$ 0	$ 0

Cash Equivalents, Marketable Debt and Equity Securities (Tables)

12 Months Ended

Dec. 31, 2025

Marketable Securities [Abstract]

Schedule of Marketable Securities

The Company’s marketable debt securities consisted of the following:


	As of December 31, 2025
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Money market funds	$	35,565	$	—	$	—	$	35,565
Corporate securities	11,966		2		—		11,968
Government securities	543,208		1,584		—		544,792
	$	590,739	$	1,586	$	—	$	592,325

Reported as
Cash equivalents							$	35,565
Marketable debt securities							556,760
Total							$	592,325


	As of December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Money market funds	$	26,180	$	—	$	—	$	26,180
Corporate securities	142,688		185		—		142,873
Government securities	523,769		647		(1,485)		522,931
	$	692,637	$	832	$	(1,485)	$	691,984

Reported as
Cash equivalents							$	26,180
Marketable debt securities							665,804
Total							$	691,984

Schedule of Maturities of Marketable Securities

The following table summarizes the contract maturities of the Company’s marketable debt securities as of December 31, 2025:


	Amortized Cost		Estimated Fair Value
	(in thousands)
Mature in one year or less	$	380,256	$	381,158
Mature within two years	174,918		175,602
Total	$	555,174	$	556,760

Schedule of Marketable Equity Securities

The Company’s marketable equity securities consisted of the following:


	December 31,
	2025		2024
	(in thousands)
INmune Bio, Inc.	$	—	$	8,805
Viridian Therapeutics, Inc.	—		13,748
Zenas BioPharma, Inc.	112,502		25,376
	$	112,502	$	47,929

Schedule of Net Realized and Unrealized Gains (Losses) on Marketable Equity Securities

Net realized and unrealized gains (losses) on marketable equity securities, recognized in other income (expense) in the consolidated statements of operations, were as follows:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Total gains (losses) recorded on marketable equity securities	$	101,514	$	(31,422)	$	(395)
Less: Gains recorded on sale of marketable equity securities	14,388		1,280		—
Unrealized gains (losses) on securities held at the reporting date	$	87,126	$	(32,702)	$	(395)

Fair Value Measurement

12 Months Ended

Dec. 31, 2025

Fair Value Disclosures [Abstract]

Fair Value Measurement

The Company employs a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date using the exit price. Accordingly, when market observable data are not readily available, the Company’s own assumptions are used to reflect those that market participants would be presumed to use in pricing the asset or liability at the measurement date.

The carrying amounts of the Company’s financial instruments, including cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued expenses, approximate fair value due to their short-term maturities.

Assets and liabilities recorded at fair value on the consolidated balance sheets are categorized based on the level of judgment associated with inputs used to measure their fair values and the level of market price observability, as follows:

Level 1 Unadjusted quoted prices are available in active markets for identical assets or liabilities as of the reporting date.

Level 2 Pricing inputs are other than quoted prices in active markets, which are based on the following:

• Quoted prices for similar assets or liabilities in active markets;

• Quoted prices for identical or similar assets or liabilities in non-active markets; or

• Either directly or indirectly observable inputs as of the reporting date.

Level 3 Pricing inputs are unobservable and significant to the overall fair value measurement, and the determination of fair value requires significant management judgment or estimation.

In certain cases, inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. Thus, a Level 3 fair value

measurement may include inputs that are observable (Level 1 or Level 2) and unobservable (Level 3). The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and consideration of factors specific to the asset or liability.

The Company uses prices and inputs that are current as of the measurement date, including during periods of market disruption. In periods of market disruption, the ability to observe prices and inputs may be reduced for many instruments. This condition could cause an instrument to be reclassified from Level 1 to Level 2, or from Level 2 to Level 3. The Company recognizes transfers between levels at either the actual date of the event or a change in circumstances that caused the transfer. There were no transfers during the years ended December 31, 2025 and 2024. At December 31, 2025 and 2024, the Company did not have any financial assets or financial liabilities based on Level 3 measurements.

The following table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques utilized by the Company:


	December 31, 2025
	Total Fair Value		Level 1		Level 2		Level 3
	(in thousands)
Cash equivalents:
Money market funds	$	35,565	$	35,565	$	—	$	—
Marketable debt securities:
Corporate securities	11,968		—		11,968		—
Government securities	544,792		—		544,792		—
Marketable equity securities	112,502		112,502		—		—
Total financial assets	$	704,827	$	148,067	$	556,760	$	—


	December 31, 2024
	Total Fair Value		Level 1		Level 2		Level 3
	(in thousands)
Cash equivalents:
Money market funds	$	26,180	$	26,180	$	—	$	—
Marketable debt securities:
Corporate securities	142,873		—		142,873		—
Government securities	522,931		—		522,931		—
Marketable equity securities	47,929		47,929		—		—
Total financial assets	$	739,913	$	74,109	$	665,804	$	—

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

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+ Details

Cash Equivalents, Marketable Debt and Equity Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Schedule of Available-for-sale Securities
Money market funds	$ 54,073	$ 40,875
Amortized Cost	555,174
Amortized Cost	590,739	692,637
Gross Unrealized Gains	1,586	832
Gross Unrealized Losses	0	(1,485)
Marketable debt securities	556,760
Total	592,325	691,984
Cash equivalents
Schedule of Available-for-sale Securities
Total	35,565	26,180
Marketable debt securities
Schedule of Available-for-sale Securities
Total	556,760	665,804
Money market funds
Schedule of Available-for-sale Securities
Money market funds	35,565	26,180
Corporate securities
Schedule of Available-for-sale Securities
Amortized Cost	11,966	142,688
Gross Unrealized Gains	2	185
Gross Unrealized Losses	0	0
Marketable debt securities	11,968	142,873
Government securities
Schedule of Available-for-sale Securities
Amortized Cost	543,208	523,769
Gross Unrealized Gains	1,584	647
Gross Unrealized Losses	0	(1,485)
Marketable debt securities	$ 544,792	$ 522,931

Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2025	Feb. 17, 2026	Jun. 30, 2025
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36182
Entity Registrant Name	Xencor, Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-1622502
Entity Address, Address Line One	465 North Halstead Street
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Pasadena
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91107
City Area Code	626
Local Phone Number	305-5900
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	XNCR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 555,937,423
Entity Common Stock, Shares Outstanding		73,338,642
Documents Incorporated by Reference	Portions of the registrant’s proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A in connection with the registrant’s 2026 Annual Meeting of Stockholders, which will be filed subsequent to the date hereof, are incorporated by reference into Part III of this Form 10-K. Such proxy statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the registrant’s fiscal year ended December 31, 2025.
Entity Central Index Key	0001326732
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Flag	false

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax [Line Items]
Increase (decrease) in deferred tax asset valuation allowance	$ 19,300
Unrecognized tax benefits	4,597	$ 8,905	$ 8,905	$ 0
Unrecognized tax benefits, income tax penalties and interest accrued	900	$ 1,700
Unrecognized tax benefits that would impact effective tax rate	2,800
Domestic Tax Jurisdiction
Income Tax [Line Items]
Cumulative net operating loss carryforwards	341,100
Tax credit carryforwards	36,200
Operating loss carryforwards, subject to expiration	43,600
Operating loss carryforwards, not subject to expiration	297,500
State and Local Jurisdiction
Income Tax [Line Items]
Cumulative net operating loss carryforwards	171,900
Tax credit carryforwards	$ 33,200

Organization and Summary of Significant Accounting Policies - Property and Equipment (Details)	Dec. 31, 2025
Research equipment
Property and Equipment
Estimated useful lives of the assets	5 years
Furniture and fixtures
Property and Equipment
Estimated useful lives of the assets	5 years
Computers and software \| Minimum
Property and Equipment
Estimated useful lives of the assets	1 year
Computers and software \| Maximum
Property and Equipment
Estimated useful lives of the assets	3 years

Collaboration and Licensing Agreements - Third-Party License (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Collaboration research and licensing agreements
Collaborations, milestones, and royalties		$ 125,576	$ 110,493	$ 174,615
Third Party Licensee
Collaboration research and licensing agreements
Collaborations, milestones, and royalties		$ 0	$ 7,000	$ 0
Third Party Licensee \| Patent License Agreement
Collaboration research and licensing agreements
Collaborations, milestones, and royalties	$ 7,000

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details

Stock Based Compensation - FV of Employee Stock Purchase Plan (Details) - ESPP	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Weighted average assumptions for estimated fair value of employee stock purcahse plan
Expected volatility, low end of range (as a percent)	42.97%	42.97%	38.24%
Expected volatility, high end of range (as a percent)	73.25%	54.62%	55.72%
Risk-free interest rate, low end of range (as a percent)	4.22%	4.22%	0.13%
Risk-free interest rate, high end of range (as a percent)	5.40%	5.40%	5.39%
Expected dividend yield	0.00%	0.00%	0.00%
Minimum
Weighted average assumptions for estimated fair value of employee stock purcahse plan
Expected term (in years)	6 months	6 months	6 months
Maximum
Weighted average assumptions for estimated fair value of employee stock purcahse plan
Expected term (in years)	2 years	2 years	2 years

Balance Sheet Accounts - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Property and Equipment
Total gross carrying amount	$ 104,780	$ 101,979
Less: accumulated depreciation and amortization	(51,472)	(42,179)
Property and equipment, net	53,308	59,800
Lab equipment
Property and Equipment
Total gross carrying amount	43,749	40,937
Computer, software and office equipment
Property and Equipment
Total gross carrying amount	2,003	2,131
Furniture and fixtures
Property and Equipment
Total gross carrying amount	128	128
Leasehold improvements
Property and Equipment
Total gross carrying amount	52,270	51,566
Construction in progress
Property and Equipment
Total gross carrying amount	$ 6,630	$ 7,217

Organization and Summary of Significant Accounting Policies - Concentrations of Risk (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Concentrations of risk
Amounts on deposit in excess of federally insured limits approximately	$ 54.1	$ 40.8
Two Customers \| Accounts Receivable \| Customer Concentration Risk
Concentrations of risk
Concentration risk percentage	91.00%	76.00%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482836/275-10-55-18

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-20

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 954
-SubTopic 310
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478785/954-310-50-2

+ Details

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References + Details

Balance Sheet Accounts - Indefinite and Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Patents, licenses, and other intangible assets
Total finite-lived assets	$ 11,756	$ 19,284
Indefinite-lived assets	4,147	10,795
Total gross carrying amount	15,903	30,079
Accumulated amortization	(7,518)	(11,594)
Total patents, licenses, and other intangible assets, net	8,385	18,485
Patents
Patents, licenses, and other intangible assets
Total finite-lived assets	10,784	16,854
Licenses and other intangible assets
Patents, licenses, and other intangible assets
Total finite-lived assets	$ 972	$ 2,430

Liabilities Related to the Sales of Future Royalties

12 Months Ended

Dec. 31, 2025

Receivables [Abstract]

Ultomiris Royalty Sale Agreement

On November 3, 2023, the Company and OMERS entered into the Ultomiris Royalty Sale Agreement. Pursuant to the Ultomiris Royalty Sale Agreement, OMERS acquired the rights to a portion of royalties and milestones earned after July 1, 2023 associated with the existing license relating to Ultomiris® (ravulizumab-cwvz) in exchange for an upfront payment of $192.5 million. Pursuant to the Ultomiris Royalty Sale Agreement and subject to the Company’s existing license with Alexion, OMERS acquired the right to receive: (i) 100% of royalties payable on past and future sales related to Ultomiris that occur from July 1, 2023 through December 31, 2025; (ii) up to $35.0 million annually in royalties on future sales related to Ultomiris that occur from January 1, 2026 through December 31, 2028, with any royalties in excess of $35.0 million reverting to the Company; (iii) up to $12.0 million annually in royalties on future sales related to Ultomiris that occur from and after January 1, 2029, with any royalties in excess of $12.0 million reverting to the Company; and (iv) $18.0 million of a certain future sales based milestone payment pursuant to the existing license with Alexion, which was paid in the fourth quarter of 2023.

Monjuvi Royalty Sale Agreement

On November 3, 2023, the Company and OMERS entered into the Monjuvi Royalty Sale Agreement. Pursuant to the Monjuvi Royalty Sale Agreement, OMERS acquired the rights to a portion of royalties earned after July 1, 2023 associated with the existing license relating to Monjuvi®/Minjuvi® (tafasitamab-cxix) in exchange for an upfront payment of $22.5 million. Pursuant to the Monjuvi Royalty Sale Agreement and subject to the Company’s existing license with Incyte, OMERS acquired the right to receive up to $29.3 million in royalties earned after July 1, 2023 related to sales of Monjuvi/Minjuvi, with any royalties in excess of $29.3 million paid to OMERS reverting to the Company.

The Company evaluated the terms of both Ultomiris and Monjuvi Royalty Sale Agreements and concluded, in accordance with the relevant accounting guidance, that these transactions are to be accounted for as debt, with the proceeds recorded as liabilities related to the sale of future royalties on its consolidated balance sheets.

The Company accounts for the royalty financing obligations in accordance with its accounting policy for the sale of future royalties, as described in Note 1. The obligations are recorded at carrying value and amortized using the effective interest method. The Company applies the prospective method to adjust the effective interest rate based on revised

estimates of future royalty payments. As of December 31, 2025, the estimated effective interest rates were 24.2% and 17.3% for Ultomiris and Monjuvi Royalty Sale Agreements, respectively.

The following table presents the activities with respect to the liabilities related to the sales of future royalties:


	December 31,
	2025		2024
	(in thousands)
Beginning balance	$	163,606	189,483
Royalties owed to OMERS	—		834
Royalties paid to OMERS	(75,778)		(63,304)
Non-cash interest expense recognized	31,921		36,593
Ending balance	$	119,749	$	163,606

Current liabilities	43,267		48,447
Long-term liabilities	76,482		115,159
Total	$	119,749	$	163,606

Stockholders’ Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Sep. 12, 2024	Feb. 27, 2023	Jan. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock and pre-funded warrants, net of issuance cost					$ 189,179
Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Stock issued during period, shares, warrants exercised in period (in shares)			1,388,888
Class of warrant or right, exercise price of warrants or rights (in dollars per share)			$ 0.01
Note Warrant
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	3,088,888
Sale of stock, price per share (in dollar per share)	$ 17.99
Sale of stock, consideration received on transaction	$ 55,600
Sales Agreement
Subsidiary, Sale of Stock [Line Items]
Number of shares issued (in shares)				0
SVB Securities LLC \| Sales Agreement
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock and pre-funded warrants, net of issuance cost		$ 200,000		$ 200,000

Leases

12 Months Ended

Dec. 31, 2025

Leases [Abstract]

Leases

Monrovia, California: The Company leases office and laboratory space in Monrovia, California. The lease term was set to expire in December 2025 and provided an option to renew the entire premises for an additional five-year term,

which the Company elected not to exercise. Instead, on August 8, 2025, the Company entered into a seventh amendment to the lease agreement to extend the term for one year, effective January 1, 2026 through December 31, 2026.

The total lease expense associated with this amended lease is approximately $0.9 million.

Pasadena, California: In June 2021, the Company entered into a lease agreement for laboratory and office space in Pasadena, California, with a lease term through July 2035 and no renewal option. The lease includes two phases: Phase 1 commenced on August 1, 2022, and Phase 2 commenced on December 1, 2022.

The lease provides tenant improvement allowances of up to $17.0 million for Phase 1 and $3.3 million for Phase 2. In August 2022, the lease was amended to provide an additional $5.0 million in Phase 1 improvement allowance in exchange for an increase in rent.

On December 18, 2025, the Company entered into a sublease agreement to sublease a portion of its space to a third party. The sublease term commenced on February 1, 2026 and expires on January 31, 2031. The Company remains primarily obligated under the original lease agreement. There is no current impact to the Company’s financial results for the year ended December 31, 2025, as the sublease term does not commence until February 1, 2026.

San Diego, California: In August 2023, the Company entered into a sublease agreement for office space in San Diego, California, with a lease term from September 2023 through December 2027. As part of the sublease, the Company issued a $0.4 million letter of credit to the landlord, secured by a cash collateral account classified as restricted cash on the consolidated balance sheets. The amount of the letter of credit decreases over the lease term.

The Company’s lease agreements do not contain any residual value guarantees or restrictive covenants. The components of lease assets and liabilities along with their classification on the Company’s consolidated balance sheets were as follows:


		December 31,
Lease Assets and Liabilities	Classification	2025		2024
		(in thousands)
Operating lease assets	Right-of-use assets	$	37,592	$	38,341
Current operating lease liabilities	Lease liabilities	$	3,263	$	3,009
Non-current operating lease liabilities	Lease liabilities, net of current portion	$	64,735	$	65,338

The following table presents maturities of operating lease liabilities on an undiscounted basis as of December 31, 2025:


Year	Amounts
	(in thousands)
2026	$	7,816
2027	9,759
2028	9,276
2029	9,531
2030	9,794
Thereafter	48,436
Total	94,612
Less: Imputed interest	(26,614)
Total operating lease liabilities (includes current portion)	$	67,998

The following table presents lease costs, supplemental cash flow and other information:


	Year Ended December 31,
	2025		2024			2023
	(in thousands)
Operating lease cost	$	7,933	$	7,525		$	8,459
Variable lease cost	1,077		1,272			906
Total lease costs	$	9,010	$	8,797		$	9,365

Right-of-use assets adjusted in exchange for amended operating lease liabilities	$	863	$	7,166		$	2,462
Cash paid for amounts included in the measurement of lease liabilities	$	8,105	$	3,545		$	3,253

			December 31,
			2025			2024
Weighted-average remaining lease term (in years)			9.3 years			10.2 years
Weighted-average discount rate (%)			7.0		%	7.0		%

Cash Equivalents, Marketable Debt and Equity Securities

12 Months Ended

Dec. 31, 2025

Marketable Securities [Abstract]

Cash Equivalents, Marketable Debt and Equity Securities

Cash Equivalents and Marketable Debt Securities

The Company’s marketable debt securities consisted of the following:


	As of December 31, 2025
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Money market funds	$	35,565	$	—	$	—	$	35,565
Corporate securities	11,966		2		—		11,968
Government securities	543,208		1,584		—		544,792
	$	590,739	$	1,586	$	—	$	592,325

Reported as
Cash equivalents							$	35,565
Marketable debt securities							556,760
Total							$	592,325


	As of December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Money market funds	$	26,180	$	—	$	—	$	26,180
Corporate securities	142,688		185		—		142,873
Government securities	523,769		647		(1,485)		522,931
	$	692,637	$	832	$	(1,485)	$	691,984

Reported as
Cash equivalents							$	26,180
Marketable debt securities							665,804
Total							$	691,984

The following table summarizes the contract maturities of the Company’s marketable debt securities as of December 31, 2025:


	Amortized Cost		Estimated Fair Value
	(in thousands)
Mature in one year or less	$	380,256	$	381,158
Mature within two years	174,918		175,602
Total	$	555,174	$	556,760

The Company did not record any impairment losses on its marketable debt securities during the years ended December 31, 2025, 2024 and 2023.

Marketable Equity Securities

The Company’s marketable equity securities consisted of the following:


	December 31,
	2025		2024
	(in thousands)
INmune Bio, Inc.	$	—	$	8,805
Viridian Therapeutics, Inc.	—		13,748
Zenas BioPharma, Inc.	112,502		25,376
	$	112,502	$	47,929

During the year ended December 31, 2025, the Company sold its entire holdings in INmune Bio, Inc., consisting of 1,885,533 shares, for total proceeds of $13.8 million. During the same period, the Company also sold its entire holdings in Viridian Therapeutics, Inc., consisting of 717,144 shares, for total proceeds of $23.2 million.

Net realized and unrealized gains (losses) on marketable equity securities, recognized in other income (expense) in the consolidated statements of operations, were as follows:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Total gains (losses) recorded on marketable equity securities	$	101,514	$	(31,422)	$	(395)
Less: Gains recorded on sale of marketable equity securities	14,388		1,280		—
Unrealized gains (losses) on securities held at the reporting date	$	87,126	$	(32,702)	$	(395)

The increase in unrealized gains for the year ended December 31, 2025 was primarily attributable to the higher fair value of the Company’s equity investment in Zenas BioPharma, Inc.

No impairment losses were recognized on marketable equity securities during the years ended December 31, 2025 and 2023. The Company recorded impairment charges of $20.4 million related to equity securities without a readily determinable fair value during the year ended December 31, 2024.

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Income Taxes - Reconciliation to effective income tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Amount
U.S. Federal statutory income tax	$ (18,778)	$ (49,334)	$ (25,123)
Research and development tax credits	(6,965)	(12,124)	(15,816)
Change in valuation allowance	17,556	56,390	57,313
State and local income taxes	3,175	(1,860)	(1,978)
Nondeductible share-based compensation	7,069	4,712	3,132
Other tax expenses	(6)
Changes in unrecognized tax benefits	939
Foreign-derived intangible income deduction		0	(4,915)
Uncertain tax position		1,654	2,138
Deferred tax adjustment		242	(1,199)
Other adjustments	(486)	276	286
Income tax provision	$ 2,504	1,617	13,662
Percent
U.S. Federal statutory income tax	(21.00%)
Research and development tax credits	(7.80%)
Change in valuation allowance	19.60%
State and local income taxes	3.60%
Nontaxable or nondeductible items:
Nondeductible share-based compensation	7.80%
Other tax expenses	0.00%
Changes in unrecognized tax benefits	1.10%
Other adjustments	(0.50%)
Income tax provision and effective income tax rate	2.80%
State and Local Jurisdiction
Amount
Change in state rate		$ 1,661	$ (176)

Collaboration and Licensing Agreements - Novo Nordisk Health Care AG (Details) - Novo Nordisk Health Care AG - Technology License Agreement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Aug. 31, 2020
Collaboration research and licensing agreements
Revenue recognized	$ 5.0
Revenue recognition milestone method pending		$ 60.0

Organization and Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Cash and cash equivalents	$ 54,073	$ 40,875
Restricted cash	289	387
Total cash, cash equivalents and restricted cash	$ 54,362	$ 41,262	$ 54,170	$ 53,942

Cash Equivalents, Marketable Debt and Equity Securities - Net Realized and Unrealized Gains (Losses) on Marketable Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Marketable Securities [Abstract]
Total gains (losses) recorded on marketable equity securities	$ 101,514	$ (31,422)	$ (395)
Less: Gains recorded on sale of marketable equity securities	14,388	1,280	0
Unrealized gains (losses) on securities held at the reporting date	$ 87,126	$ (32,702)	$ (395)

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenue
Collaborations, milestones, and royalties	$ 125,576	$ 110,493	$ 174,615
Operating expenses:
Research and development	239,434	227,686	253,598
General and administrative	63,644	61,215	53,379
Total operating expenses	303,078	288,901	306,977
Operating loss	(177,502)	(178,408)	(132,362)
Other income (expense):
Interest income	27,524	31,930	19,331
Interest expense	(31,927)	(36,643)	(6,177)
Gain (loss) on marketable equity securities, net	101,514	(31,422)	(395)
Asset impairment charges	(9,169)	(20,430)	0
Other, net	(73)	50	(31)
Total other income (expense)	87,869	(56,515)	12,728
Loss before income tax expense and noncontrolling interest	(89,633)	(234,923)	(119,634)
Income tax expense	2,504	1,617	13,662
Net loss including noncontrolling interest	(92,137)	(236,540)	(133,296)
Net loss attributable to noncontrolling interest	(214)	(3,922)	(163)
Net loss attributable to Xencor, Inc.	$ (91,923)	$ (232,618)	$ (133,133)
Net loss per share attributable to Xencor, Inc. - basic (in dollars per share)	$ (1.24)	$ (3.58)	$ (2.20)
Net loss per share attributable to Xencor, Inc. - diluted (in dollars per share)	$ (1.24)	$ (3.58)	$ (2.20)
Weighted-average shares used in calculating net loss per share - basic (in shares)	74,239,000	65,041,000	60,503,000
Weighted-average shares used in calculating net loss per share - diluted (in shares)	74,239,000	65,041,000	60,503,000
Other comprehensive income (loss), net of tax:
Net unrealized gain (loss) on marketable debt securities	$ 2,239	$ (1,954)	$ 8,243
Comprehensive loss	(89,898)	(238,494)	(125,053)
Less: comprehensive loss attributable to the noncontrolling interest	(214)	(3,922)	(163)
Comprehensive loss attributable to Xencor, Inc.	$ (89,684)	$ (234,572)	$ (124,890)

Segment Reporting - Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total	$ 125,576	$ 110,493	$ 174,615
Research and development stock based compensation	(43,227)	(53,281)	(53,755)
General and administrative	(63,644)	(61,215)	(53,379)
Other income (expense), net	87,869	(56,515)	12,728
Income tax expense	(2,504)	(1,617)	(13,662)
Net loss including noncontrolling interest	(92,137)	(236,540)	(133,296)
Reportable Segment
Segment Reporting Information [Line Items]
Total	125,576	110,493	174,615
Internal research and development expenses	(94,783)	(91,948)	(99,401)
Research and development stock based compensation	(24,970)	(29,955)	(34,516)
General and administrative	(63,644)	(61,215)	(53,379)
Other income (expense), net	87,869	(56,515)	12,728
Income tax expense	(2,504)	(1,617)	(13,662)
Net loss including noncontrolling interest	(92,137)	(236,540)	(133,296)
Reportable Segment \| XmAb819 (ENPP3 x CD3)
Segment Reporting Information [Line Items]
External research and development expense	(23,119)	(10,735)	(6,808)
Reportable Segment \| XmAb657 (CD19 x CD3)
Segment Reporting Information [Line Items]
External research and development expense	(13,767)	(2,644)	0
Reportable Segment \| XmAb942 (Xtend TL1A)
Segment Reporting Information [Line Items]
External research and development expense	(13,419)	(18,654)	(946)
Reportable Segment \| XmAb541 (CLDN6 x CD3)
Segment Reporting Information [Line Items]
External research and development expense	(12,742)	(4,068)	(8,237)
Reportable Segment \| XmAb412 (TL1A x IL-23p19)
Segment Reporting Information [Line Items]
External research and development expense	(8,064)	0	0
Reportable Segment \| Plamotamab (CD20 x CD3)
Segment Reporting Information [Line Items]
External research and development expense	(7,229)	(6,015)	(1,787)
Reportable Segment \| XmAb808 (B7-H3 x CD28)
Segment Reporting Information [Line Items]
External research and development expense	(5,888)	(8,210)	(7,168)
Reportable Segment \| Other programs including research and early stage
Segment Reporting Information [Line Items]
External research and development expense	(18,229)	(28,037)	(40,407)
Reportable Segment \| Wind down costs of terminated programs
Segment Reporting Information [Line Items]
External research and development expense	(17,224)	(27,420)	(54,328)
License
Segment Reporting Information [Line Items]
Total	0	8,500	0
License \| Reportable Segment
Segment Reporting Information [Line Items]
Total	0	8,500	0
Milestone
Segment Reporting Information [Line Items]
Total	45,300	34,500	88,500
Milestone \| Reportable Segment
Segment Reporting Information [Line Items]
Total	45,300	34,500	88,500
Royalties
Segment Reporting Information [Line Items]
Total	80,276	67,493	55,795
Royalties \| Reportable Segment
Segment Reporting Information [Line Items]
Total	80,276	67,493	55,795
Collaboration
Segment Reporting Information [Line Items]
Total	0	0	30,320
Collaboration \| Reportable Segment
Segment Reporting Information [Line Items]
Total	$ 0	$ 0	$ 30,320

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Schedule of Stock by Class

The following table summarizes the Company’s shares of common stock and preferred stock:


		Shares
	Par Value	Authorized	Issued	Outstanding

As of December 31, 2025
Common Stock	$0.01	200,000,000	71,871,975	71,871,975
Preferred Stock	$0.01	10,000,000	—	—

As of December 31, 2024
Common Stock	$0.01	200,000,000	70,256,108	70,256,108
Preferred Stock	$0.01	10,000,000	—	—

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27))
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-Topic 210
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Organization and Summary of Significant Accounting Policies - Accounts Receivable (Details)	12 Months Ended
	Dec. 31, 2025
Minimum
Accounts Receivable Collection Period [Line Items]
Collection period	30 days
Maximum
Accounts Receivable Collection Period [Line Items]
Collection period	60 days

Employee Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
Employee Benefit Plans (Details) - USD ($) $ in Millions	Apr. 01, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan employer matching contribution percent	4.50%
Vesting period		3 years
Employer contributions		$ 1.6	$ 1.6	$ 1.7
2% of participating employee contributions
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching to defined contribution plan	100.00%
Defined contribution plan employer matching contribution percent	2.00%
5% of participating employee contributions
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching to defined contribution plan	50.00%
Defined contribution plan employer matching contribution percent	5.00%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Leases - Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Lease Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Leases [Abstract]
Operating lease cost	$ 7,933	$ 7,525	$ 8,459
Variable lease cost	1,077	1,272	906
Total lease costs	9,010	8,797	9,365
Right-of-use assets adjusted in exchange for amended operating lease liabilities	863	7,166	2,462
Cash paid for amounts included in the measurement of lease liabilities	$ 8,105	$ 3,545	$ 3,253
Weighted-average remaining lease term (in years)		9 years 3 months 18 days	10 years 2 months 12 days
Weighted-average discount rate (%)	7.00%	7.00%

Collaboration and Licensing Agreements - Alexion Pharmaceutical, Inc. (Details) $ in Thousands		12 Months Ended
	Jan. 01, 2013 program	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Collaboration research and licensing agreements
Collaborations, milestones, and royalties		$ 125,576	$ 110,493	$ 174,615
Accounts receivable		29,299	60,849
Royalties
Collaboration research and licensing agreements
Collaborations, milestones, and royalties		80,276	67,493	55,795
Alexion
Collaboration research and licensing agreements
Collaborations, milestones, and royalties		70,070	58,213	64,891
Alexion \| Option and License Agreement
Collaboration research and licensing agreements
Number of different target programs \| program	1
Collaborations, milestones, and royalties				20,000
Accounts receivable		19,700
Alexion \| Non-Cash Royalty \| Option and License Agreement
Collaboration research and licensing agreements
Revenue recognized		$ 70,100	$ 58,200	12,500
Alexion \| Cash Royalty \| Option and License Agreement
Collaboration research and licensing agreements
Revenue recognized				$ 32,400

Stockholders’ Equity - Stock by Class (Details) - $ / shares	Dec. 31, 2025	Dec. 31, 2024
Equity [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	71,871,975	70,256,108
Common stock, shares outstanding (in shares)	71,871,975	70,256,108
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred Stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Organization and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Organization and Summary of Significant Accounting Policies

Organization

Xencor, Inc. (the “Company”) was incorporated in California in 1997 and reincorporated in Delaware in September 2004. The Company is a clinical-stage biopharmaceutical company focused on discovering and developing engineered antibody therapeutics to treat patients with cancer and autoimmune diseases, who have unmet medical needs. The Company uses its protein engineering capabilities to design new technologies and XmAb® drug candidates with improved properties. The Company advances these candidates into clinical-stage development, where the Company is conducting Phase 1 and Phase 2 studies for a broad portfolio of programs. Based on the results of these studies, the Company determines which programs to advance into later stages of development and potentially commercialization, which to partner in order to access complementary resources to optimize development, and which to discontinue.

Consolidation and Basis of Presentation

The consolidated financial statements of Xencor, Inc. have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). In the opinion of management, all material adjustments of a normal recurring nature have been made to present fairly the Company’s financial position, the results of operations and cash flows for the periods presented. All intercompany transactions and balances have been eliminated.

Gale Therapeutics Inc. (“Gale”)

The consolidated financial statements included the accounts of Xencor, Inc. and Gale, a variable interest entity for which the Company was the primary beneficiary. Up through January 20, 2025, the Company owned or was exposed to less than 100% of the economics, and accordingly, the Company recorded net loss attributable to noncontrolling interests in its consolidated statements of operations and comprehensive loss equal to the percentage of the economic or ownership interests retained in such entity by the respective noncontrolling party. Effective January 20, 2025, the Company obtained 100% of the economic interests in Gale and no longer recognized a noncontrolling interest in its consolidated financial statements.

Effective April 29, 2025, Gale was merged into the Company in a transaction between entities under common control. The Company completed a common-control transfer of assets and liabilities with Gale. The assets and liabilities were recognized at historical carrying amounts; no fair value measurement was applied. This transaction did not result in a change in reporting entity and was accounted for prospectively, with no adjustments to prior periods.

Summary of Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. The Company bases its estimates on historical experience and on various other assumptions that it believes to be reasonable. Actual results could materially differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments purchased with original maturities of 90 days or less from the date of purchase to be cash equivalents. As of December 31, 2025 and 2024, the Company’s cash equivalents comprised of money market funds with maturities less than 90 days from the date of purchase. Cash equivalents are reported at fair value.

As part of the San Diego facility lease, the Company issued a letter of credit to the landlord, secured by a cash collateral account classified as restricted cash on the consolidated balance sheets. The amount of the letter of credit decreases over the lease term. As of December 31, 2025, the outstanding letter of credit was $0.3 million.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the consolidated statements of cash flows:


	December 31,
	2025		2024
	(in thousands)
Cash and cash equivalents	$	54,073	$	40,875
Restricted cash	289		387
Total cash, cash equivalents and restricted cash	$	54,362	$	41,262

Marketable Debt and Equity Securities

The Company classifies all marketable debt securities as available-for-sale, as such securities may be required to be sold prior to maturity. Management determines the appropriate classification at the time of purchase. Marketable debt securities with original maturities greater than three months and remaining maturities of twelve months or less as of the balance sheet date are classified as short-term marketable debt securities.

Available-for-sale securities are carried at fair value, with unrealized gains and losses recorded as a component of other comprehensive income (loss) until realized. The amortized cost of these securities is adjusted for the amortization of premiums and accretion of discounts to maturity, which are included in interest income.

The Company regularly evaluates its marketable debt securities for declines in fair value. In assessing whether a decline represents a credit-related impairment, the Company considers, among other factors, the creditworthiness of the issuer, the severity and duration of the unrealized loss, and whether the Company intends or is more likely than not required to sell the security before recovery of its amortized cost basis. Credit-related losses are recognized in net income, while non-credit-related losses are recorded in other comprehensive income (loss). Realized gains and losses are included in other income (expense), and the cost of securities sold is determined using the specific identification method. Interest and dividends earned on available-for-sale securities are included in interest income.

Accrued interest on available-for-sale debt securities is recorded in prepaid expenses and other current assets on the Company's consolidated balance sheets. For purposes of measuring credit-related impairments, the Company excludes accrued interest from the amortized cost basis and fair value of available-for-sale securities and does not record an allowance for credit losses on accrued interest. Any uncollectible accrued interest would be written off as a reversal of interest income in the period it is determined to be uncollectible. To date, no accrued interest has been written off.

The Company also holds equity securities in publicly traded biotechnology companies that were received in connection with certain licensing transactions with its partners. These equity securities are measured at fair value, with changes in fair value recognized in earnings and reported in the consolidated statements of operations. Equity securities with readily determinable fair values are measured at each reporting period until the investment is sold or otherwise disposed of. Upon sale or disposition of an equity security, any realized gains or losses are recognized in the consolidated statements of operations in the period of sale. As of December 31, 2025 and 2024, all of the Company’s holdings of equity securities were publicly traded and had readily determinable fair values.

See Note 3. Marketable Securities and Note 4. Fair Value Measurement for additional information.

Accounts Receivable

Accounts receivable primarily consist of royalty and milestone receivables from the Company’s license and collaboration agreements, as well as receivables arising from cost-sharing development activities. Payment terms under the Company’s agreements generally require settlement within 30 to 60 days.

The Company evaluates accounts receivable for expected credit losses in accordance with Accounting Standards Codification 326, Financial Instruments – Credit Losses. As of December 31, 2025 and 2024, based on this evaluation, the Company determined that an allowance for credit losses was not material and, accordingly, no allowance was recorded.

Concentrations of Risk

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, marketable securities, and accounts receivable.

Cash and cash equivalents and restricted cash are maintained at reputable financial institutions, and balances may at times exceed federally insured limits. The Company has not experienced any losses related to these balances. Amounts on deposit in excess of federally insured limits at December 31, 2025 and 2024 approximated $54.1 million and $40.8 million, respectively. The Company also invests excess cash in corporate debt securities and government securities with strong credit ratings. The Company has established guidelines related to diversification and maturities designed to maintain safety

and liquidity and periodically reviews and modifies these guidelines to respond to trends in yields and interest rates without compromising safety or liquidity.

Concentrations of credit risk related to accounts receivable arise from the Company’s licensing and collaboration agreements. As of December 31, 2025 and 2024, receivables from two customers represented approximately 91% and 76% of the Company’s total accounts receivable, respectively. No other customer accounted for more than 10% of total accounts receivable at December 31, 2025 or 2024.

Property and Equipment

Property and equipment are recorded at cost, net of accumulated depreciation, with depreciation commencing when the asset is placed in service. Depreciation expense is recorded on a straight-line basis over the estimated useful lives of the assets. Upon disposition, the cost and accumulated depreciation of assets retired or sold are removed from the respective asset category, and any gain or loss is recognized in the Company’s consolidated statement of operations. The estimated useful lives of property and equipment are as follows (in years):


			Estimated Useful Lives
Research equipment			5
Furniture and fixtures			5
Computers and software			1 to 3
Leasehold Improvements			Shorter of asset life or remaining lease term

The Company periodically assesses long-lived assets or asset groups, including property and equipment, for recoverability when events or changes in circumstances indicate that their carrying amounts may not be recoverable. If the Company identifies an indicator of impairment, the Company assesses recoverability by comparing the carrying amount of the asset to the sum of the undiscounted cash flows expected to result from the use and the eventual disposal of the asset. An impairment loss is recognized when the carrying amount is not recoverable and is measured as the excess of carrying value over fair value. There were no impairment charges during the years ended December 31, 2025, 2024, and 2023.

Patents, Licenses, and Other Intangible Assets

Patents, licenses and other intangible assets with definite useful lives are amortized on a straight-line basis over their useful lives, ranging from 2 to 27 years. Third-party costs incurred for acquiring patents are capitalized if there is a determined future economic benefit; otherwise, the Company expenses costs as incurred in connection with patent applications (including direct application fees, and the legal and consulting expenses related to making such applications) in general and administrative expenses in the consolidated statements of operations and comprehensive loss.

The Company reviews its intellectual property on a regular basis to determine if there are changes in the estimated useful life of issued patents and if any capitalized costs for unissued patents should be abandoned. Capitalized patent costs related to abandoned patent filings are charged off in the period of the decision to abandon. Abandonment charges for the years ended 2025, 2024 and 2023 were $0, $2.3 million and $1.3 million, respectively.

Liabilities Related to the Sales of Future Royalties

The Company accounts for proceeds received from the sale of future royalties as financial liabilities in accordance with the debt classification model. These liabilities are amortized using the effective interest method over the estimated life of the royalty sale agreements based on the Company’s current estimate of future royalty payments to be made to OMERS.

The excess of the total expected royalty payments over the net proceeds received is recognized as non-cash interest expense over the life of the liability. Interest is imputed on the unamortized portion of the liability using the effective interest method and is recorded based on the timing of royalty payments to be made to OMERS over the term of the royalty sale agreement. The effective interest rate is affected by the timing and amount of forecasted royalty payments.

The Company’s estimate of future royalty payments is reviewed quarterly. Because the effective interest rate is dependent on the timing and amount of forecasted revenue, any significant changes in those estimates result in a prospective adjustment to the effective interest rate and related interest expense. Under the prospective method, a revised effective interest rate is determined based on the updated estimate of remaining cash flows and represents the discount rate that equates the present value of the revised estimated cash flows to the carrying amount of the liability at the date of revision. The revised rate is applied prospectively to recognize non-cash interest expense over the remaining term of the arrangement. Royalty revenue continues to be recognized as earned, and royalty payments made to the counterparty are recorded as a reduction of the liability when paid and are not recognized as a component of the Company’s revenue. For further information regarding the terms and carrying values of these instruments, see Note 6.

Revenue Recognition

The revenue standard provides a five-step framework for recognizing revenue as control of promised goods or services is transferred to a customer at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To determine revenue recognition, the Company performs the following five steps: (i) identify the contract; (ii) identify the performance obligations; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. At contract inception, the Company assesses whether the goods or services promised within each contract are distinct and, therefore, represent a separate performance obligation, or whether they are not distinct and are combined with other goods and services. The Company then determines the transaction price, allocates the transaction price to the performance obligations, and recognizes revenue when (or as) each performance obligation is satisfied.

Upfront license payments are recognized as revenue upon delivery of the license, provided the license is determined to be distinct from other performance obligations in the contract and the customer has the ability to use and benefit from the license. Other performance obligations typically include research and development services. If a license is not distinct, the license and related services are combined into a single performance obligation, and revenue is recognized either at a point in time or over time, depending on the nature of the combined performance obligation. For performance obligations satisfied over time, the Company recognizes revenue using a measure of progress that reflects the transfer of control of goods or services to the customer and reassesses this measure each reporting period.

Collaboration agreements may also provide for milestone payments and royalties. Milestones are generally categorized as development, regulatory, or sales-based milestones. The Company includes milestone and royalty consideration in the transaction price only to the extent that it is probable that a significant reversal of cumulative revenue recognized will not occur. Consideration that meets this threshold is included in the transaction price using the most likely amount method; amounts that do not meet this threshold are excluded until the uncertainty is resolved. The Company reassesses this estimate each reporting period and records any changes to the transaction price on a cumulative catch-up basis.

Milestone payments that were excluded from the transaction price due to the variable consideration constraint are recognized as revenue in the period in which the uncertainty is resolved. If a milestone is achieved during the performance period, revenue is recognized based on the extent of performance completed, with any remaining amount recorded as deferred revenue. Sales-based or usage-based royalties related to licenses of intellectual property are recognized at the later of when the related sales occur or when the associated performance obligation has been satisfied, in accordance with the sales-based royalty exception.

Research and Development (“R&D”) Expense and Accrued R&D Expenses

R&D expenses are expensed as incurred and include costs for the Company’s internal research activities as well as fees paid to third-party vendors, including clinical research organizations (“CROs”), contract manufacturing organizations (“CMOs”), preclinical research organizations, clinical sites, research institutions, and other service providers. R&D expenses consist primarily of salaries and benefits, including stock-based compensation, laboratory supplies, facilities and applicable overhead costs, external services, clinical trial and manufacturing costs, and fees paid to third parties that conduct research and development activities on the Company’s behalf.

The Company records accrued R&D expenses for services that have been performed but not yet invoiced based on estimates of the services provided to date. Accruals are determined using available information, including contractual terms, the progress of preclinical and clinical activities, patient enrollment and dosing information, preclinical study progress, and communications with third-party vendors regarding services rendered. Estimates are adjusted as additional information becomes available or as invoices are received, and such adjustments are recorded in the period in which the information becomes known.

Payments made for R&D services prior to the services being rendered are recorded as prepaid assets in the consolidated balance sheets and expensed as the related services are performed.

Leases

The Company determines whether a contract is, or contains, a lease at inception. All of the Company’s leases are classified as operating leases. Leases with terms greater than one-year are recognized on the Company’s consolidated balance sheets as right-of-use assets that represent the Company’s right to use an underlying asset for the lease term, and lease liabilities that represent its obligation to make lease payments arising from the lease. Lease assets and liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the expected lease

term. As of December 31, 2025 and 2024, the Company is not reasonably certain that it will exercise renewal options for any lease facilities. Therefore, these options are not included in the right-of-use assets and liabilities.

The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes the appropriate incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis an amount equal to the lease payments over a similar term and in a similar economic environment. The Company records expense to recognize lease payments on a straight-line basis over the expected lease term. Costs determined to be variable and not based on an index or rate are not included in the measurement of the lease liability and are expensed as incurred.

Stock-Based Compensation

Share-based compensation expense for all stock-based awards, including stock options, restricted stock units (“RSUs”), and shares issued under the Employee Stock Purchase Plan (“ESPP”), is measured based on the estimated grant-date fair value of the awards and recognized as compensation expense over the requisite service period, generally the vesting period, on a straight-line basis. The Company accounts for forfeitures as they occur.

The grant-date fair value of stock option awards is estimated using the Black-Scholes option pricing model, which requires the use of subjective assumptions, including expected term, expected volatility, risk-free interest rate, and expected dividend yield. Expected volatility and expected term are primarily based on the Company’s historical data and other relevant information, while the risk-free interest rate is based on U.S. Treasury yields in effect at the time of grant with a maturity commensurate with the expected term of the award. The Company does not assume any expected dividend yield, as it has never declared or paid dividends on its common stock.

Income Taxes

Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial reporting basis and the respective tax basis of the Company’s assets and liabilities, and expected benefits of utilizing net operating loss, capital loss, and tax-credit carryforwards. The Company assesses the likelihood that its deferred tax assets will be realized and, to the extent management does not believe these assets are more likely than not to be realized, a valuation allowance is established. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates or laws is recognized in earnings in the period that includes the enactment date. As of December 31, 2025 and 2024, the Company’s deferred tax assets, consisting primarily of capitalized R&D under IRC Section 174, net operating loss carryforwards and research and development tax credit carryforwards, have been fully offset by a valuation allowance.

On July 4, 2025, the One Big Beautiful Bill Act (“OBBBA”) was signed into law, making permanent key elements of the Tax Cuts and Jobs Act, including 100% bonus depreciation, reinstating the option to expense domestic research and development costs, and increasing the limitation on business interest expense deduction. The Company has evaluated the impact of the new tax law on its financial condition and results of operations and determined it is not material to its effective income tax rate and net deferred federal income tax assets, as it continues to maintain a full valuation allowance.

Net Loss Per Share

Net loss per share is computed using the weighted-average number of common shares outstanding and pre-funded warrants during the period. Diluted earnings per share is computed using the weighted-average number and dilutive potential common shares outstanding during the period. Dilutive potential common shares primarily consist of outstanding stock options, restricted stock units and ESPP.

Comprehensive Loss

Comprehensive loss consists of net loss in excess of unrealized gains and losses on marketable debt securities. The Company displays comprehensive loss and its components as part of the consolidated statements of operations and comprehensive loss.

Segment Information

The Company operates as a single segment because its chief operating decision maker (“CODM”) reviews operating results on an aggregate basis and manages its operations as a single operating segment.

Recent Accounting Pronouncements

In September 2025, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2025-06, Intangible - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Improvements to Internal-

Use Software, to amend certain aspects of the accounting for and disclosure of software costs. This ASU will become effective for the Company beginning January 1, 2028, and is not expected to have a material impact on its consolidated financial statements or related disclosures.

In September 2025, the FASB issued ASU 2025-05, Financial Instruments - Credit Losses (Subtopic 326): Practical Expedient for Reasonable and Supportable Forecasts, which allows entities to elect a practical expedient that assumes current conditions as of the balance sheet date remain unchanged over the remaining life of the asset when developing reasonable and supportable forecasts used to estimate expected credit losses. This ASU will become effective for the Company beginning January 1, 2026, and is not expected to have a material impact on its consolidated financial statements or related disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. In January 2025, the FASB also issued ASU 2025-01, Clarifying the Effective Date, to provide further guidance on the transition period for the new requirements. These updates require entities to provide disaggregated disclosures of income statement expenses. These ASUs do not affect the expense captions presented on the face of the income statement but instead require the disaggregation of certain expense captions into specified categories within the footnotes to the financial statements. These ASUs will become effective for the Company beginning January 1, 2027, and the Company is currently evaluating the impact on its consolidated financial statements and related disclosures.

Recently Adopted Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which requires expanded disclosure of income tax rate reconciliation information and income taxes paid. The Company adopted this standard effective January 1, 2025, on a prospective basis. The adoption of this standard resulted in increased disclosures in the Company’s consolidated financial statements but did not have a material impact on the Company’s financial position, results of operations, or cash flows. See Note 11 – Income Taxes for the additional disclosures required by this ASU.

Collaboration and Licensing Agreements - Novartis Institute for Biomedical Research, Inc. (Details) - Novartis - Collaboration and License Agreement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Jun. 30, 2016
Collaboration research and licensing agreements
Revenue recognized	$ 4.0
Revenue recognition milestone method pending		$ 309.0

Income Taxes

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Income Taxes

Income Tax Provision

Income tax provision consisted of the following:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Current
Federal	$	(671)	$	513	$	11,472
State	3,175		1,104		2,190
Total current tax	$	2,504	$	1,617	$	13,662

Deferred
Federal	$	—	$	—	$	—
State	—		—		—
Total deferred tax	$	—	$	—	$	—
Income tax provision	$	2,504	$	1,617	$	13,662

The following table presents a reconciliation of the tax expense based on the statutory rate to the Company’s actual tax expense in the consolidated statements of operations and comprehensive loss. A notional 21% tax rate was applied as follows:


	Year Ended December 31, 2025
	Amount		Percent
	(in thousands)
U.S. Federal statutory income tax	$	(18,778)	(21.0)	%
Research and development tax credits	(6,965)		(7.8)	%
Change in valuation allowance	17,556		19.6	%
State and local income taxes (1)	3,175		3.6	%
Nontaxable or nondeductible items:
Nondeductible share-based compensation	7,069		7.8	%
Other tax expenses	(6)		—	%
Changes in unrecognized tax benefits	939		1.1	%
Other adjustments	(486)		(0.5)	%
Income tax provision and effective income tax rate	$	2,504	2.8	%

(1) State taxes in Massachusetts, Minnesota, New York, and New York City represented the majority (greater than 50 percent) of the tax eﬀect in this category.


	Year Ended December 31,
	2024		2023
	(in thousands)
U.S. Federal statutory income tax	$	(49,334)	$	(25,123)
Research and development tax credits	(12,124)		(15,816)
Change in valuation allowance	56,390		57,313
State and local income taxes	(1,860)		(1,978)
Stock-based compensation	4,712		3,132
Change in state rate	1,661		(176)
Foreign-derived intangible income deduction	—		(4,915)
Uncertain tax position	1,654		2,138
Deferred tax adjustment	242		(1,199)
Other	276		286
Income tax provision	$	1,617	$	13,662

Income Taxes Paid, Net of Refunds

Cash paid for income taxes, net of refunds, consisted of the following:


	Year Ended December 31, 2025
	Amount
	(in thousands)
Jurisdiction:
Federal	$	7,359
State	(47)
Total	$	7,312

Deferred Income Taxes

The following table presents the significant components of the Company’s net deferred tax assets and liabilities:


	December 31,
	2025		2024
	(in thousands)
Deferred tax assets:
Net operating loss carryforwards	$	83,754	$	36,355
Capitalized research and development costs	80,894		93,844
Tax credits	60,487		48,419
Accrued compensation	20,935		21,274
Royalty financing	17,208		28,123
Lease liabilities	14,594		14,956

Equity investments	—		4,025
Other	4		—
Total gross deferred tax assets	277,876		246,996
Valuation allowance	(246,617)		(227,268)
Total deferred tax assets, net of valuation allowance	31,259		19,728
Deferred tax liabilities:
Intangibles	(958)		(2,066)

Depreciation	(8,373)		(9,272)
Right-of-use assets	(8,068)		(8,390)
Equity investments	(13,860)		—
Total gross deferred tax liabilities	(31,259)		(19,728)
Net deferred tax assets (liabilities)	$	—	$	—

The Company has net deferred tax assets primarily related to capitalized research and development costs, net operating loss carryforwards, and research and development tax credit carryforwards. Due to uncertainty regarding the realization of these deferred tax assets in future tax periods, the Company has recorded a valuation allowance against its deferred tax assets as of December 31, 2025 and 2024. Valuation allowances are recognized to reduce deferred tax assets to the amount that is more likely than not to be realized. The Company has concluded that its net deferred tax assets are not more likely than not to be realized due to cumulative losses incurred in prior years and the lack of sufficient sources of future taxable income. During the year ended December 31, 2025, the valuation allowance increased by $19.3 million.

As of December 31, 2025, the Company had cumulative net operating loss carryforwards for federal and state income tax purposes of $341.1 million and $171.9 million, respectively, and available tax credit carryforwards of approximately $36.2 million for federal income tax purposes and $33.2 million for state income tax purposes, which may be available to offset future taxable income, if any. Of the cumulative net operating loss carryforwards for federal, $43.6 million were generated prior to January 1, 2018 and are subject to expiration, while $297.5 million were incurred after December 31, 2017 and may be carried forward indefinitely, subject to an annual limitation of 80% of future taxable income. To the extent permitted by law, taxing authorities may examine tax returns for prior periods in which net operating losses were generated or utilized and may make adjustments up to the amount of the net operating loss carryforwards claimed.

Federal net operating loss carryforwards begin to expire in 2027, and state net operating loss carryforwards begin to expire in 2035. Federal tax credit carryforwards begin to expire in 2042. Utilization of the Company’s net operating loss and tax credit carryforwards is subject to annual limitations under Section 382 of the Internal Revenue Code due to ownership changes previously experienced by the Company. As a result, certain net operating loss and tax credit carryforwards may expire before being utilized.

Uncertainty in Income Taxes

The following table summarizes the Company’s gross unrecognized tax benefits:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Balance at January 1	$	8,905	$	8,905	$	—
Increase related to prior period tax positions	1,464		—		1,054
Decrease related to prior period tax positions	(6,653)		—		—
Increase related to current year tax positions	1,234		—		7,851
Decrease related to settlements with tax authorities	(353)		—		—

Gross unrecognized tax benefits at December 31	$	4,597	$	8,905	$	8,905

Unrecognized tax benefits were $4.6 million, $8.9 million and $8.9 million for the years ended December 31, 2025, 2024 and 2023, respectively. The decrease in prior year unrecognized tax benefits relates primarily to the conclusion of the Internal Revenue Service (“IRS”) audit for the 2022 tax year and the related impact on the 2023 federal and certain 2022 and 2023 state income tax filings.

The Company files U.S. federal and state income tax returns in jurisdictions with varying statutes of limitations. As of December 31, 2025, the Company’s federal income tax returns for tax years 2023 and forward remain subject to examination by the IRS. For state income tax purposes, tax years 2022 and forward generally remain subject to examination by the respective state tax authorities. In addition, the use of net operating losses or tax credits generated in tax years prior to 2022 may subject returns for those years to examination. The Company will occasionally enter into voluntary disclosure agreements with states, where the statute of limitations would otherwise remain open for all years.

The Company’s policy is to recognize interest and penalties related to income taxes, if any, as a component of income tax expense. The accrued interest and penalties related to unrecognized tax benefits were $0.9 million and $1.7 million as of December 31, 2025 and 2024, respectively. If the unrecognized tax benefits as of December 31, 2025 were ultimately recognized, $2.8 million would affect the effective tax rate, subject to changes in the valuation allowance.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477617/942-740-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478822/944-740-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12C

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12B

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-17

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	71,871,975	70,256,108
Common stock, shares outstanding (in shares)	71,871,975	70,256,108

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense

Income tax provision consisted of the following:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Current
Federal	$	(671)	$	513	$	11,472
State	3,175		1,104		2,190
Total current tax	$	2,504	$	1,617	$	13,662

Deferred
Federal	$	—	$	—	$	—
State	—		—		—
Total deferred tax	$	—	$	—	$	—
Income tax provision	$	2,504	$	1,617	$	13,662

Schedule of Reconciliation of the Federal Statutory Income Tax Rate to Our Effective Income Tax Rate


	Year Ended December 31, 2025
	Amount		Percent
	(in thousands)
U.S. Federal statutory income tax	$	(18,778)	(21.0)	%
Research and development tax credits	(6,965)		(7.8)	%
Change in valuation allowance	17,556		19.6	%
State and local income taxes (1)	3,175		3.6	%
Nontaxable or nondeductible items:
Nondeductible share-based compensation	7,069		7.8	%
Other tax expenses	(6)		—	%
Changes in unrecognized tax benefits	939		1.1	%
Other adjustments	(486)		(0.5)	%
Income tax provision and effective income tax rate	$	2,504	2.8	%

(1) State taxes in Massachusetts, Minnesota, New York, and New York City represented the majority (greater than 50 percent) of the tax eﬀect in this category.


	Year Ended December 31,
	2024		2023
	(in thousands)
U.S. Federal statutory income tax	$	(49,334)	$	(25,123)
Research and development tax credits	(12,124)		(15,816)
Change in valuation allowance	56,390		57,313
State and local income taxes	(1,860)		(1,978)
Stock-based compensation	4,712		3,132
Change in state rate	1,661		(176)
Foreign-derived intangible income deduction	—		(4,915)
Uncertain tax position	1,654		2,138
Deferred tax adjustment	242		(1,199)
Other	276		286
Income tax provision	$	1,617	$	13,662

Schedule of Cash Paid for Income Taxes, Net of Refunds

Cash paid for income taxes, net of refunds, consisted of the following:


	Year Ended December 31, 2025
	Amount
	(in thousands)
Jurisdiction:
Federal	$	7,359
State	(47)
Total	$	7,312

Schedule of Tax Effect of Temporary Differences That Give Rise to a Significant Portion of the Deferred Tax Assets and Liabilities

The following table presents the significant components of the Company’s net deferred tax assets and liabilities:


	December 31,
	2025		2024
	(in thousands)
Deferred tax assets:
Net operating loss carryforwards	$	83,754	$	36,355
Capitalized research and development costs	80,894		93,844
Tax credits	60,487		48,419
Accrued compensation	20,935		21,274
Royalty financing	17,208		28,123
Lease liabilities	14,594		14,956

Equity investments	—		4,025
Other	4		—
Total gross deferred tax assets	277,876		246,996
Valuation allowance	(246,617)		(227,268)
Total deferred tax assets, net of valuation allowance	31,259		19,728
Deferred tax liabilities:
Intangibles	(958)		(2,066)

Depreciation	(8,373)		(9,272)
Right-of-use assets	(8,068)		(8,390)
Equity investments	(13,860)		—
Total gross deferred tax liabilities	(31,259)		(19,728)
Net deferred tax assets (liabilities)	$	—	$	—

Schedule of Unrecognized Tax Benefits Roll Forward

The following table summarizes the Company’s gross unrecognized tax benefits:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Balance at January 1	$	8,905	$	8,905	$	—
Increase related to prior period tax positions	1,464		—		1,054
Decrease related to prior period tax positions	(6,653)		—		—
Increase related to current year tax positions	1,234		—		7,851
Decrease related to settlements with tax authorities	(353)		—		—

Gross unrecognized tax benefits at December 31	$	4,597	$	8,905	$	8,905

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation From time to time, the Company may be subject to claims and legal proceedings arising in the ordinary course of business. The Company evaluates each matter and assesses its potential financial exposure. If the potential loss from a legal proceeding is considered probable and the amount can be reasonably estimated, the Company records an accrual for the estimated loss. Because the outcome of legal proceedings is inherently uncertain, significant judgment is required in assessing the likelihood of a loss and whether the amount is reasonably estimable. The Company’s assessments and any recorded accruals are based on information available at the time of evaluation. As additional information becomes available, the Company re-evaluates its estimates and may adjust recorded liabilities accordingly. The Company is currently a party to an action initiated by Merus N.V. (“Merus”) in the District of Delaware alleging that the Company’s manufacture, use, offer for sale, sale and/or importation of common light chain antibodies and heterodimeric antibodies infringes certain claims of Merus patents. Merus filed its complaint against the Company on August 5, 2024. Merus asserted claims of U.S. Patent Nos. 9,944,695, 9,358,286 and 11,926,859. Merus sought a judgment of patent infringement, an order enjoining the Company from infringing those patents, a damages award (together with interest), a declaration of willful infringement, and a finding that this case is exceptional. On October 10, 2024, the Company filed a motion to dismiss the Merus complaint with prejudice under Rule 12(b)(6), in which the Company argued that all of the activities accused of infringement are covered by the 35 U.S.C.§ 271(e)(1) safe harbor. Merus filed its response to the Company’s motion on October 31, 2024, and the Company replied to Merus’ response on November 14, 2024. On September 30, 2025, the Court granted the motion to dismiss Merus’ complaint, but permitted Merus to file an amended complaint. On November 11, 2025, Merus filed a first amended complaint, and asserted claims of U.S. Patent Nos. 9,944,695, 9,358,286, 11,926,859, and 12,123,043. On December 16, 2025, the Company filed a motion to dismiss the first amended complaint on the same grounds previously asserted. Briefing on the motion to dismiss is ongoing, and the Court held a hearing on the motion to dismiss on February 17, 2026. On February 11, 2025, the Company filed for inter partes review of Merus’ U.S. Patent Nos. 9,358,286 and 11,926,859 before the U.S. Patent and Trademark Office’s Patent and Trial Appeal Board (“PTAB”) seeking a finding that certain claims of those patents are unpatentable. On September 26, 2025, the U.S. Patent and Trademark Appeal Board granted institution of the inter partes review. A schedule for the inter partes review has been set, and oral argument is scheduled for June 24, 2026. The Company believes it has strong defenses to Merus’ claims, including defenses of invalidity and/or non-infringement—some of which have already been accepted by the district court and preliminarily accepted by the PTAB, but there is no guarantee that the Company will ultimately prevail. Commitments The Company is party to certain license agreements that obligate it to make future payments to third parties, which may include sublicense fees, royalties and milestone payments contingent upon the achievement of specified development and commercialization events. Because the occurrence, timing and amounts of these potential payments are not currently probable or reasonably estimable, they have not been recorded on the Company’s consolidated balance sheets as of December 31, 2025 and 2024. In addition, the Company has entered into agreements with various third-party vendors for research, development and manufacturing services. These agreements generally provide for future payments contingent upon the vendors’ delivery of goods or performance of services. Such commitments are not recorded until the related goods or services are received.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

In June 2023, the Company’s Board of Directors (the “Board”) and stockholders approved the 2023 Equity Incentive Plan (the “2023 Plan”), which became effective on June 14, 2023, and replaced the 2013 Equity Incentive Plan (the “2013 Plan”). No additional awards may be granted under the 2013 Plan.

The 2023 Plan reserves 3,000,000 shares of common stock, plus any remaining shares available under the 2013 Plan as of the effective date. In addition, shares subject to outstanding awards under the 2013 Plan that expire, are forfeited, or otherwise terminate without being issued after June 14, 2023, will be added to the 2023 Plan share reserve. The 2023 Plan does not include an automatic annual share increase (an evergreen provision). On June 12, 2025, the Company’s stockholders approved the amendment and restatement of the 2023 Plan to increase the number of authorized shares reserved for issuance thereunder by 3,000,000 shares. As of December 31, 2025, the total number of shares of common stock reserved for issuance under the 2023 Plan is 19,878,573.

In addition, the Company’s Board and stockholders approved the ESPP, which became effective on December 5, 2013. As of December 31, 2025, the total number of shares of common stock available for issuance under the ESPP is 817,666.

The following table presents a summary of awards outstanding:


	As of December 31, 2025
	2013 Plan	2023 Plan	Total
Stock options	8,625,426	4,331,166	12,956,592
RSUs	215,336	1,766,009	1,981,345
	8,840,762	6,097,175	14,937,937

The following table summarizes stock-based compensation expenses included in operating expenses:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
General and administrative	$	18,257	$	23,326	$	19,239
Research and development	24,970		29,955		34,516
	$	43,227	$	53,281	$	53,755


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Stock options	$	22,768	$	31,147	$	29,345
RSUs	19,594		21,276		23,167
ESPP	865		858		1,243
	$	43,227	$	53,281	$	53,755

Stock Option Awards

The following table presents a summary of the stock option activity for the year ended December 31, 2025:


	Number of Shares Subject to Outstanding Options	Weighted Average Exercise Price (per share)		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2024	12,370,081	$	28.59	5.9	$	10,386
Granted	2,116,680	12.99
Exercised	(644,705)	13.44
Forfeited	(885,464)	26.61
Outstanding at December 31, 2025	12,956,592	$	26.93	5.6	$	5,156
Exercisable at December 31, 2025	9,324,358	$	30.14	4.5	$	867

The aggregate intrinsic values represent the amount by which the market price of the underlying stock exceeds the exercise price of the option. The total intrinsic value of the options exercised during the years ended December 31, 2025, 2024, and 2023 were $2.0 million, $3.8 million, and $4.8 million, respectively.

As of December 31, 2025, the unrecognized compensation expense for all outstanding unvested stock options in the amount of $31.8 million will be recognized in the Company’s results of operations over a weighted average period of 2.2 years.

The per share weighted average grant date fair values of the stock options granted are $7.10, $12.06, and $15.98 for the years ended December 31, 2025, 2024 and 2023, respectively. The following table provides the weighted-average assumptions used in the calculation of grant date per share fair values of these stock options based on the Black-Scholes option pricing model:


	Year Ended December 31,
	2025			2024			2023
Expected term (in years) (1)	6.4			6.4			6.1
Expected volatility (2)	51.2		%	50.2		%	50.5		%
Risk-free interest rate (3)	4.1		%	4.2		%	4.2		%
Expected dividend yield (4)	—		%	—		%	—		%
Underlying stock price	$	12.99		$	22.31		$	30.02

(1) The computation of expected term was determined based on the option holders’ past exercise patterns.

(2) Volatility is estimated based on volatility average of the Company’s common stock price.

(3) The risk-free interest rate is based on that of the U.S. Treasury yields with equivalent terms in effect at the time of the grant.

(4) The dividend yield is zero as the Company currently does not pay a dividend.

Restricted Stock Units (“RSUs”)

The following table summarizes the activity of the Company’s RSUs:


	Restricted Stock Units	Weighted Average Grant Date Fair Value (Per unit)
Outstanding as of December 31, 2024	1,783,795	$	25.52
Granted	1,204,787	13.23
Vested	(843,722)	26.53
Forfeited	(163,515)	19.46
Outstanding as of December 31, 2025	1,981,345	$	18.01

The fair value of RSUs was determined based on the closing price of the Company’s common stock on the grant date.

As of December 31, 2025, there was $20.0 million of total unrecognized compensation cost related to RSUs that is expected to be recognized over a weighted-average period of 1.8 years.

Employee Stock Purchase Plan

The following table provides the assumptions used in the calculation of grant date fair values of these shares issued under the Company’s ESPP based on the Black-Scholes option pricing model:


	Year Ended December 31,
	2025		2024		2023
Expected term (in years) (1)	0.5 - 2.0		0.5 - 2.0		0.5 - 2.0
Expected volatility (2)	42.97% - 73.25%		42.97% - 54.62%		38.24% - 55.72%
Risk-free interest rate (3)	4.22% - 5.40%		4.22% - 5.40%		0.13% - 5.39%
Expected dividend yield (4)	—	%	—	%	—	%

(1) The computation of expected term was determined based on the option holders’ past exercise patterns.

(2) Volatility is estimated based on volatility average of the Company’s common stock price.

(3) The risk-free interest rate is based on that of the U.S. Treasury yields with equivalent terms in effect at the time of the grant.

(4) The dividend yield is zero as the Company currently does not pay a dividend.

As of December 31, 2025, there was no unrecognized pre-tax compensation expense related to outstanding shares issued under the Company’s ESPP.

Balance Sheet Accounts (Tables)

12 Months Ended

Dec. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Property and Equipment

The following table summarizes the Company’s major classes of property and equipment:


	December 31,
	2025		2024
	(in thousands)
Lab equipment	$	43,749	$	40,937
Computer, software and office equipment	2,003		2,131
Furniture and fixtures	128		128
Leasehold improvements	52,270		51,566
Construction in progress	6,630		7,217
Total gross carrying amount	104,780		101,979
Less: accumulated depreciation and amortization	(51,472)		(42,179)
Property and equipment, net	$	53,308	$	59,800

Schedule of Finite-Lived Intangible Assets

The following table summarizes the Company’s patents, licenses, and other intangible assets:


	December 31,
	2025		2024
	(in thousands)
Patents	$	10,784	$	16,854
Licenses and other intangible assets	972		2,430
Total finite-lived assets	11,756		19,284
Indefinite-lived assets	4,147		10,795
Total gross carrying amount	15,903		30,079
Accumulated amortization	(7,518)		(11,594)
Total patents, licenses, and other intangible assets, net	$	8,385	$	18,485

Schedule of Indefinite-Lived Intangible Assets

The following table summarizes the Company’s patents, licenses, and other intangible assets:


	December 31,
	2025		2024
	(in thousands)
Patents	$	10,784	$	16,854
Licenses and other intangible assets	972		2,430
Total finite-lived assets	11,756		19,284
Indefinite-lived assets	4,147		10,795
Total gross carrying amount	15,903		30,079
Accumulated amortization	(7,518)		(11,594)
Total patents, licenses, and other intangible assets, net	$	8,385	$	18,485

Schedule of Future Amortization Expense for Patents, Licenses, and Other Intangible Assets

The following table presents the estimated future amortization expense related to definite-lived assets as of December 31, 2025:


	Amortization Expense
Year ending December 31,	(in thousands)
2026	$	547
2027	705
2028	585
2029	375
2030	351
Thereafter	1,675
Total	$	4,238

Schedule of Accrued Expenses

Accrued expenses consist of the following:


	December 31,
	2025		2024
	(in thousands)
Accrued R&D expenses	$	12,858	$	2,324

Accrued payroll and benefits	20,209		14,849
Other	1,893		2,044
Total accrued expenses	$	34,960	$	19,217

Stock Based Compensation - Share-Based Payment Arrangement, Activity (Details) - shares	Dec. 31, 2025	Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options (in shares)	12,956,592	12,370,081
Total
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options (in shares)	12,956,592
Total (in shares)	14,937,937
The 2013 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options (in shares)	8,625,426
Total (in shares)	8,840,762
The 2023 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options (in shares)	4,331,166
Total (in shares)	6,097,175
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
RSUs (in shares)	1,981,345	1,783,795
RSUs \| Total
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
RSUs (in shares)	1,981,345
RSUs \| The 2013 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
RSUs (in shares)	215,336
RSUs \| The 2023 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
RSUs (in shares)	1,766,009

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Organization and Summary of Significant Accounting Policies (Polices)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Consolidation and Basis of Presentation

Gale Therapeutics Inc. (“Gale”)

Use of Estimates

Cash, Cash Equivalents and Restricted Cash

Marketable Debt and Equity Securities

Accounts Receivable

Concentrations of Risk

and liquidity and periodically reviews and modifies these guidelines to respond to trends in yields and interest rates without compromising safety or liquidity.

Property and Equipment


			Estimated Useful Lives
Research equipment			5
Furniture and fixtures			5
Computers and software			1 to 3
Leasehold Improvements			Shorter of asset life or remaining lease term

Patents, Licenses, and Other Intangible Assets

Revenue Recognition

Research and Development (“R&D”) Expense and Accrued R&D Expenses

Payments made for R&D services prior to the services being rendered are recorded as prepaid assets in the consolidated balance sheets and expensed as the related services are performed.

Leases

Stock-Based Compensation

Recent Accounting Pronouncements and Recently Adopted Accounting Pronouncements

Recent Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Income Taxes - Income taxes paid (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Federal	$ 7,359
State	(47)
Total	$ 7,312	$ 6,100	$ 0

Collaboration and Licensing Agreements - Incyte Corporation (Details) - USD ($) $ in Thousands		1 Months Ended		12 Months Ended
	Dec. 29, 2025	Jun. 30, 2025	Feb. 28, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Collaboration research and licensing agreements
Accounts receivable				$ 29,299	$ 60,849
MorphoSys \| Collaboration and License Agreement
Collaboration research and licensing agreements
Proceeds from milestone payments	$ 4,000	$ 25,000	$ 12,500
Revenue recognition milestone method pending				195,000
MorphoSys \| Collaboration and License Agreement \| Non-Cash Royalty
Collaboration research and licensing agreements
Revenue recognized				10,200	$ 8,700	$ 2,100
MorphoSys \| Collaboration and License Agreement \| Cash Royalty
Collaboration research and licensing agreements
Revenue recognized						$ 6,600
MorphoSys \| Collaboration and License Agreement \| Royalties
Collaboration research and licensing agreements
Accounts receivable				3,000
OCM Life Sciences Portfolio LP (OMERS) \| Monjuvi Royalty Sale Agreement
Collaboration research and licensing agreements
Proceeds from milestone payments				$ 41,500

Organization and Summary of Significant Accounting Policies - Patents, Licenses, and Other Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 9.2
Impairment, Intangible Asset, Statement of Income or Comprehensive Income [Extensible Enumeration]	Asset impairment charges
Licensing Agreements
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 0.0	$ 2.3	$ 1.3
Impairment, Intangible Asset, Statement of Income or Comprehensive Income [Extensible Enumeration]	Asset impairment charges	Asset impairment charges	Asset impairment charges
Minimum \| Licensing Agreements
Finite-Lived Intangible Assets [Line Items]
Estimated economic life	2 years
Maximum \| Licensing Agreements
Finite-Lived Intangible Assets [Line Items]
Estimated economic life	27 years

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

The table below details the Company’s revenues and expenses and reconciles those amounts to the Company’s consolidated net loss including noncontrolling interest as computed under U.S. GAAP in the consolidated statements of operations and comprehensive loss:


	Year Ended December 31,
	2025		2024 (2)		2023 (2)
	(in thousands)
Revenues:
License	$	—	$	8,500	$	—
Milestone	45,300		34,500		88,500
Royalties	80,276		67,493		55,795
Collaboration	—		—		30,320
Total revenues	125,576		110,493		174,615
Less:
Research and development:
XmAb819 (ENPP3 x CD3)	(23,119)		(10,735)		(6,808)
XmAb657 (CD19 x CD3)	(13,767)		(2,644)		—
XmAb942 (Xtend TL1A)	(13,419)		(18,654)		(946)
XmAb541 (CLDN6 x CD3)	(12,742)		(4,068)		(8,237)
XmAb412 (TL1A x IL-23p19)	(8,064)		—		—
Plamotamab (CD20 x CD3)	(7,229)		(6,015)		(1,787)
XmAb808 (B7-H3 x CD28)	(5,888)		(8,210)		(7,168)
Other programs including research and early stage	(18,229)		(28,037)		(40,407)
Wind down costs of terminated programs	(17,224)		(27,420)		(54,328)
Internal research and development expenses	(94,783)		(91,948)		(99,401)
Research and development stock based compensation	(24,970)		(29,955)		(34,516)
General and administrative	(63,644)		(61,215)		(53,379)
Other income (expense), net (1)	87,869		(56,515)		12,728
Income tax expense	(2,504)		(1,617)		(13,662)
Net loss including noncontrolling interest	$	(92,137)	$	(236,540)	$	(133,296)

(1) Other income (expense), net, included interest income, interest expense, gain/loss on marketable equity securities and asset impairment charges.

(2) The Company has retrospectively adjusted segment operating expenses for the years ended on December 31, 2024 and 2023 to reflect the significant segment expenses as currently reviewed by the CODM.

Collaboration and Licensing Agreements - Janssen Biotech, Inc., a Johnson & Johnson company (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Oct. 31, 2021	Nov. 30, 2020
Collaboration research and licensing agreements
Collaborations, milestones, and royalties	$ 125,576	$ 110,493	$ 174,615
Janssen
Collaboration research and licensing agreements
Collaborations, milestones, and royalties	$ 0	$ 0	77,820
Janssen \| Collaboration and License Agreement
Collaboration research and licensing agreements
Revenue recognition milestone method pending					$ 640,000
Janssen \| Second Collaboration and License Agreement
Collaboration research and licensing agreements
Revenue recognition milestone method pending				$ 636,300
Collaborations, milestones, and royalties			$ 77,800

- Definition

+ References

+ Details

Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Schedule of Cash and Cash Equivalents


	December 31,
	2025		2024
	(in thousands)
Cash and cash equivalents	$	54,073	$	40,875
Restricted cash	289		387
Total cash, cash equivalents and restricted cash	$	54,362	$	41,262

Schedule of Restricted Cash and Cash Equivalents


	December 31,
	2025		2024
	(in thousands)
Cash and cash equivalents	$	54,073	$	40,875
Restricted cash	289		387
Total cash, cash equivalents and restricted cash	$	54,362	$	41,262

Schedule of Useful Lives by Asset Category

The estimated useful lives of property and equipment are as follows (in years):


			Estimated Useful Lives
Research equipment			5
Furniture and fixtures			5
Computers and software			1 to 3
Leasehold Improvements			Shorter of asset life or remaining lease term

Stock Based Compensation - Employee Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	$ 43,227	$ 53,281	$ 53,755
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	22,768	31,147	29,345
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	19,594	21,276	23,167
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	865	858	1,243
General and administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	18,257	23,326	19,239
General and administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	$ 24,970	$ 29,955	$ 34,516

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Collaboration and Licensing Agreements - Amgen Inc. (Details) - Amgen - Research and License Agreement - USD ($) $ in Millions	1 Months Ended
	Dec. 31, 2024	Dec. 31, 2025
Collaboration research and licensing agreements
Revenue recognized	$ 30.0
Revenue recognition milestone method pending		$ 225.0

Stock Based Compensation - Narrative (Details) - USD ($)		12 Months Ended
	Jun. 12, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Jun. 14, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total intrinsic value of the options exercised		$ 2,000,000.0	$ 3,800,000	$ 4,800,000
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance (in shares)		817,666
Unamortized compensation expense		$ 0
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized compensation expense		$ 31,800,000
Period to recognize unamortized compensation expense		2 years 2 months 12 days
Weighted average grant date fair values (in dollars per share)		$ 7.10	$ 12.06	$ 15.98
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Period to recognize unamortized compensation expense		1 year 9 months 18 days
Cost not yet recognized amount		$ 20,000,000.0
The 2023 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance (in shares)		19,878,573			3,000,000
Number of additional shares authorized (in shares)	3,000,000

Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2025

Fair Value Disclosures [Abstract]

Schedule of Assets Recorded at Fair Value


	December 31, 2025
	Total Fair Value		Level 1		Level 2		Level 3
	(in thousands)
Cash equivalents:
Money market funds	$	35,565	$	35,565	$	—	$	—
Marketable debt securities:
Corporate securities	11,968		—		11,968		—
Government securities	544,792		—		544,792		—
Marketable equity securities	112,502		112,502		—		—
Total financial assets	$	704,827	$	148,067	$	556,760	$	—


	December 31, 2024
	Total Fair Value		Level 1		Level 2		Level 3
	(in thousands)
Cash equivalents:
Money market funds	$	26,180	$	26,180	$	—	$	—
Marketable debt securities:
Corporate securities	142,873		—		142,873		—
Government securities	522,931		—		522,931		—
Marketable equity securities	47,929		47,929		—		—
Total financial assets	$	739,913	$	74,109	$	665,804	$	—

Cash Equivalents, Marketable Debt and Equity Securities - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Equity Securities
Proceeds from sale of common stock		$ 189,179,000
Impairment losses on marketable equity securities	$ 0	$ 20,400,000	$ 0
INmune Bio, Inc.
Equity Securities
Issuance of common stock and pre-funded warrants, net of issuance cost (in shares)	1,885,533
Proceeds from sale of common stock	$ 13,800,000
Viridian Therapeutics, Inc.
Equity Securities
Issuance of common stock and pre-funded warrants, net of issuance cost (in shares)	717,144
Proceeds from sale of common stock	$ 23,200,000

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References + Details

Income Taxes - Components on Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Current
Federal	$ (671)	$ 513	$ 11,472
State	3,175	1,104	2,190
Total current tax	2,504	1,617	13,662
Deferred
Federal	0	0	0
State	0	0	0
Total deferred tax	0	0	0
Income tax provision	$ 2,504	$ 1,617	$ 13,662

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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+ Details

Stock Based Compensation - Restricted Stock Units (Details) - RSUs	12 Months Ended
	Dec. 31, 2025 $ / shares shares
Restricted Stock Units
Beginning balance (in shares) \| shares	1,783,795
Granted (in shares) \| shares	1,204,787
Vested (in shares) \| shares	(843,722)
Forfeited (in shares) \| shares	(163,515)
Ending balance (in shares) \| shares	1,981,345
Weighted Average Grant Date Fair Value (Per unit)
Balance at the beginning of the period (in dollars per share) \| $ / shares	$ 25.52
Granted (in dollars per share) \| $ / shares	13.23
Vested (in dollars per share) \| $ / shares	26.53
Forfeited (in dollars per share) \| $ / shares	19.46
Balance at the end of the period (in dollars per share) \| $ / shares	$ 18.01

Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Deferred tax assets:
Net operating loss carryforwards	$ 83,754	$ 36,355
Capitalized research and development costs	80,894	93,844
Tax credits	60,487	48,419
Accrued compensation	20,935	21,274
Royalty financing	17,208	28,123
Lease liabilities	14,594	14,956
Equity investments	0	4,025
Other	4	0
Total gross deferred tax assets	277,876	246,996
Valuation allowance	(246,617)	(227,268)
Total deferred tax assets, net of valuation allowance	31,259	19,728
Deferred tax liabilities:
Intangibles	(958)	(2,066)
Depreciation	(8,373)	(9,272)
Right-of-use assets	(8,068)	(8,390)
Equity investments	(13,860)	0
Total gross deferred tax liabilities	(31,259)	(19,728)
Net deferred tax assets (liabilities)	$ 0	$ 0

Leases (Tables)

12 Months Ended

Dec. 31, 2025

Leases [Abstract]

Schedule of Lease Costs and Cash Disclosures


		December 31,
Lease Assets and Liabilities	Classification	2025		2024
		(in thousands)
Operating lease assets	Right-of-use assets	$	37,592	$	38,341
Current operating lease liabilities	Lease liabilities	$	3,263	$	3,009
Non-current operating lease liabilities	Lease liabilities, net of current portion	$	64,735	$	65,338

The following table presents lease costs, supplemental cash flow and other information:


	Year Ended December 31,
	2025		2024			2023
	(in thousands)
Operating lease cost	$	7,933	$	7,525		$	8,459
Variable lease cost	1,077		1,272			906
Total lease costs	$	9,010	$	8,797		$	9,365

Right-of-use assets adjusted in exchange for amended operating lease liabilities	$	863	$	7,166		$	2,462
Cash paid for amounts included in the measurement of lease liabilities	$	8,105	$	3,545		$	3,253

			December 31,
			2025			2024
Weighted-average remaining lease term (in years)			9.3 years			10.2 years
Weighted-average discount rate (%)			7.0		%	7.0		%

Schedule of Operating Lease Liabilities Maturities

The following table presents maturities of operating lease liabilities on an undiscounted basis as of December 31, 2025:


Year	Amounts
	(in thousands)
2026	$	7,816
2027	9,759
2028	9,276
2029	9,531
2030	9,794
Thereafter	48,436
Total	94,612
Less: Imputed interest	(26,614)
Total operating lease liabilities (includes current portion)	$	67,998

Collaboration and Licensing Agreements (Tables)

12 Months Ended

Dec. 31, 2025

Collaboration and Licensing Agreements

Schedule of Revenue by Licenses

The following table provides a summary of revenue recognized:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Alexion	$	70,070	$	58,213	$	64,891
Amgen	—		30,000		—


Gilead	—		—		6,000
Janssen	—		—		77,820
Incyte	51,696		8,693		8,700
Mabgeek	1,800		1,500		—
Novartis	—		4,000		—
Omeros	—		—		5,000
Vega	—		500		—
Vir Bio	2,010		587		2,204

Zenas	—		—		10,000
Third Party Licensee	—		7,000		—
Total	$	125,576	$	110,493	$	174,615

Schedule of Disaggregation of Revenue

The following table presents a disaggregation of revenue recognized during the periods indicated:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
License	$	—	$	8,500	$	—
Milestone	45,300		34,500		88,500
Royalties	80,276		67,493		55,795
Collaboration	—		—		30,320
Total	$	125,576	$	110,493	$	174,615

Schedule of Receivables and Contract Liabilities

The following table summarizes the balance of receivables and contract liabilities related to the Company’s collaboration and license agreements:


	December 31,
	2025		2024
	(in thousands)
Receivables included in accounts receivable	$	29,299	$	53,546
Contract liabilities included in deferred revenue	$	—	$	—

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Stock Based Compensation - Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Number of Shares Subject to Outstanding Options
Balance at the beginning of the period (in shares)	12,370,081
Granted (in shares)	2,116,680
Exercised (in shares)	(644,705)
Forfeited (in shares)	(885,464)
Balance at the end of the period (in shares)	12,956,592	12,370,081
Exercisable (in shares)	9,324,358
Weighted Average Exercise Price (per share)
Balance at the beginning of the period (in dollars per share)	$ 28.59
Granted (in dollars per share)	12.99
Exercised (in dollars per share)	13.44
Forfeited (in dollars per share)	26.61
Balance at the end of the period (in dollars per share)	26.93	$ 28.59
Exercisable (in dollars per share)	$ 30.14
Weighted Average Remaining Contractual Term (in years)
Weighted-average remaining contractual life	5 years 7 months 6 days	5 years 10 months 24 days
Weighted-average remaining contractual term, exercisable	4 years 6 months
Aggregate intrinsic value, balance outstanding	$ 5,156	$ 10,386
Aggregate intrinsic value, exercisable	$ 867

Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Numerator:
Net loss attributable to Xencor, Inc.	$ (91,923)	$ (232,618)	$ (133,133)
Denominator:
Weighted-average basic shares outstanding (in shares)	74,239,000	65,041,000	60,503,000
Effect of dilutive securities (in shares)	0	0	0
Weighted-average diluted shares outstanding (in shares)	74,239,000	65,041,000	60,503,000
Basic net loss per share (in dollars per share)	$ (1.24)	$ (3.58)	$ (2.20)
Diluted net loss per common share (in dollars per share)	$ (1.24)	$ (3.58)	$ (2.20)
Antidilutive securities excluded from computation of earnings per share (in shares)	245,313	646,288	1,081,938
Options
Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	5,108	376,441	868,085
Restricted stock units
Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	240,205	269,847	213,853

Stock Based Compensation - FV of Employee Stock Options (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Weighted average assumptions for estimated fair value of employee stock options
Expected term (in years)	6 years 4 months 24 days	6 years 4 months 24 days	6 years 1 month 6 days
Expected volatility (as a percent)	51.20%	50.20%	50.50%
Risk-free interest rate (as a percent)	4.10%	4.20%	4.20%
Expected dividend yield	0.00%	0.00%	0.00%
Underlying stock price (in dollars per share)	$ 12.99	$ 22.31	$ 30.02

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Cybersecurity Risk Management and Strategy Disclosure	Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	The Company’s management maintains a cybersecurity program, with direct oversight from the Audit Committee (the “Audit Committee”) of the Board of Directors (the “Board”), to manage information, data, technology security, and procedures and practices. The cybersecurity program is informed in part by the National Institute of Standards and Technology Cybersecurity Framework (NIST CSF), which provides guidance to help identify, assess, and manage cybersecurity risks relevant to the Company’s business. The Company seeks to address material cybersecurity threats through a company-wide approach that addresses the confidentiality, integrity, and availability of the Company’s information systems and the information that it collects and stores, by assessing, identifying and managing cybersecurity issues as they arise. Consistent with this approach, the Company applies cybersecurity practices informed by a Zero Trust-aligned security philosophy that emphasizes continuous verification, least-privilege access, and risk-based controls across its information systems. Cybersecurity Risk Management and Strategy The Company maintains a cross-functional, enterprise-wide cybersecurity risk management program that is integrated into its overall risk management framework and operating processes. Cybersecurity risks are evaluated alongside other enterprise risks as part of the Company’s broader risk assessment activities, including consideration of their potential impact on the Company’s business operations, financial condition, results of operations, and reputation. Senior management is actively involved in identifying, assessing, and managing cybersecurity risks, and the Board, primarily through the Audit Committee, provides oversight of these risks. Identification and Escalation of Cybersecurity Risks: The Company maintains processes and controls designed to identify, assess, and manage cybersecurity threats and incidents that could be material. These processes are intended to enable the timely identification, classification, and escalation of cybersecurity incidents to appropriate levels of management based on the nature, severity, and potential impact of the incident. Management is informed of cybersecurity incidents through defined escalation protocols, which facilitate coordination among information technology, legal, finance, and other relevant functions and support management’s evaluation of incident severity, response actions, and disclosure considerations. Significant cybersecurity risks and incidents are reported to the Audit Committee, as appropriate, and the Audit Committee provides oversight of management’s response and remediation efforts. Cybersecurity Controls and Monitoring: The Company’s cybersecurity program includes administrative, technical, and physical safeguards designed to protect the confidentiality, integrity, and availability of the Company’s information systems. These safeguards are supported by ongoing monitoring activities, vulnerability assessments, and cybersecurity threat intelligence, and are periodically evaluated through internal reviews and independent third-party assessments. The results of these activities are reviewed by management and used to inform enhancements to the Company’s cybersecurity risk management practices. Incident Response and Recovery: The Company maintains an incident response and recovery plan designed to guide the Company’s response to cybersecurity incidents. The plan defines roles and responsibilities, escalation and reporting protocols, coordination with internal and external stakeholders, and post-incident review processes. A cross-functional incident response team, led by the Company’s head of Information Technology and including representatives from finance, legal, human resources, corporate communications, and executive leadership, supports the execution of the plan. Management monitors incident response efforts and determines whether any cybersecurity incident is material and requires disclosure, and provides updates to the Audit Committee regarding significant incidents and remediation efforts, as appropriate. Third-Party Risk Management: The Company assesses and manages cybersecurity risks associated with third-party service providers as part of the Company’s overall cybersecurity risk management program. Third parties are evaluated using a risk-based approach that considers their access to the Company’s systems and data and the criticality of the services provided. Based on assessed risk levels, the Company applies oversight measures commensurate with the level of risk, which may include contractual requirements, assessments, audits, or other assurance activities. Training, Assessment, and Continuous Improvement: The Company provides regular cybersecurity training and awareness programs for employees designed to promote the identification and reporting of cybersecurity threats and reinforce the Company’s information security policies and practices. The Company also conducts periodic reviews, testing, and independent assessments of its cybersecurity program. The results of these activities are evaluated by management, reported to the Audit Committee, and used to inform ongoing enhancements to the Company’s cybersecurity risk management strategy.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	The Company maintains a cross-functional, enterprise-wide cybersecurity risk management program that is integrated into its overall risk management framework and operating processes. Cybersecurity risks are evaluated alongside other enterprise risks as part of the Company’s broader risk assessment activities, including consideration of their potential impact on the Company’s business operations, financial condition, results of operations, and reputation. Senior management is actively involved in identifying, assessing, and managing cybersecurity risks, and the Board, primarily through the Audit Committee, provides oversight of these risks.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	The Board, in coordination with the Audit Committee, oversees the Company’s risk management and information technology programs, including the management of cybersecurity risks. The Audit Committee receives regular reports and presentations regarding cybersecurity matters, including the Company’s risk management practices, recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, the threat environment, technological trends, and information security issues encountered by the Company, its peers, and third parties. The Audit Committee also receives updates regarding significant cybersecurity risks and incidents, as appropriate. On a quarterly basis, the Audit Committee discusses the Company’s approach to cybersecurity risk oversight with members of senior management. The Company’s head of Information Technology, who has over 30 years of relevant experience in information security, in coordination with senior management, including the Chief Financial Officer, is responsible for managing the Company’s cybersecurity risk management program. The head of Information Technology works collaboratively across the Company to implement and maintain processes designed to protect the Company’s information systems from cybersecurity threats and to respond to cybersecurity incidents in accordance with the Company’s incident response and recovery plans. Cross-functional teams throughout the Company support the cybersecurity program by addressing cybersecurity risks and responding to incidents, and provide relevant information to the head of Information Technology and senior management, who report significant cybersecurity matters to the Audit Committee, as appropriate.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Board, in coordination with the Audit Committee, oversees the Company’s risk management and information technology programs, including the management of cybersecurity risks.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Audit Committee receives regular reports and presentations regarding cybersecurity matters, including the Company’s risk management practices, recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, the threat environment, technological trends, and information security issues encountered by the Company, its peers, and third parties.
Cybersecurity Risk Role of Management [Text Block]	The Audit Committee receives regular reports and presentations regarding cybersecurity matters, including the Company’s risk management practices, recent developments, evolving standards, vulnerability assessments, third-party and independent reviews, the threat environment, technological trends, and information security issues encountered by the Company, its peers, and third parties. The Audit Committee also receives updates regarding significant cybersecurity risks and incidents, as appropriate. On a quarterly basis, the Audit Committee discusses the Company’s approach to cybersecurity risk oversight with members of senior management.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	The Company’s head of Information Technology, who has over 30 years of relevant experience in information security, in coordination with senior management, including the Chief Financial Officer, is responsible for managing the Company’s cybersecurity risk management program.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	The Company’s head of Information Technology, who has over 30 years of relevant experience in information security, in coordination with senior management, including the Chief Financial Officer, is responsible for managing the Company’s cybersecurity risk management program. The head of Information Technology works collaboratively across the Company to implement and maintain processes designed to protect the Company’s information systems from cybersecurity threats and to respond to cybersecurity incidents in accordance with the Company’s incident response and recovery plans. Cross-functional teams throughout the Company support the cybersecurity program by addressing cybersecurity risks and responding to incidents, and provide relevant information to the head of Information Technology and senior management, who report significant cybersecurity matters to the Audit Committee, as appropriate.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	The head of Information Technology works collaboratively across the Company to implement and maintain processes designed to protect the Company’s information systems from cybersecurity threats and to respond to cybersecurity incidents in accordance with the Company’s incident response and recovery plans. Cross-functional teams throughout the Company support the cybersecurity program by addressing cybersecurity risks and responding to incidents, and provide relevant information to the head of Information Technology and senior management, who report significant cybersecurity matters to the Audit Committee, as appropriate.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Non-Controlling Interest
Beginning balance (in shares) at Dec. 31, 2022		59,998,000
Beginning balance at Dec. 31, 2022	$ 727,496	$ 601	$ 1,072,132	$ (6,952)	$ (338,285)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	53,755		53,755
Exercise of stock options (in shares)		344,000
Exercise of stock options	3,412	$ 3	3,409
Issuance of restricted stock units (in shares)		558,000
Issuance of restricted stock units	0	$ 6	(6)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		98,000
Issuance of common stock under the Employee Stock Purchase Plan	1,977	$ 1	1,976
Contribution from noncontrolling interest owners	500					500
Net unrealized gain (loss) on marketable debt securities	8,243			8,243
Net loss	(133,296)				(133,133)	(163)
Ending balance (in shares) at Dec. 31, 2023		60,998,000
Ending balance at Dec. 31, 2023	662,087	$ 611	1,131,266	1,291	(471,418)	337
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	53,281		53,281
Exercise of stock options (in shares)		459,000
Exercise of stock options	6,313	$ 4	6,309
Issuance of restricted stock units (in shares)		609,000
Issuance of restricted stock units	0	$ 6	(6)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		96,000
Issuance of common stock under the Employee Stock Purchase Plan	1,660	$ 1	1,659
Issuance of common stock and pre-funded warrants, net of issuance cost (in shares)		8,094,000
Issuance of common stock and pre-funded warrants, net of issuance cost	189,179	$ 81	189,098
Net unrealized gain (loss) on marketable debt securities	(1,954)			(1,954)
Net loss	(236,540)				(232,618)	(3,922)
Ending balance (in shares) at Dec. 31, 2024		70,256,000
Ending balance at Dec. 31, 2024	674,026	$ 703	1,381,607	(663)	(704,036)	(3,585)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	43,227		43,227
Exercise of stock options (in shares)		645,000
Exercise of stock options	8,667	$ 6	8,661
Issuance of restricted stock units (in shares)		844,000
Issuance of restricted stock units	0	$ 8	(8)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		127,000
Issuance of common stock under the Employee Stock Purchase Plan	1,290	$ 1	1,289
Net unrealized gain (loss) on marketable debt securities	2,239			2,239
Purchase of noncontrolling interest	(1,725)		(5,524)			3,799
Net loss	(92,137)				(91,923)	(214)
Ending balance (in shares) at Dec. 31, 2025		71,872,000
Ending balance at Dec. 31, 2025	$ 635,587	$ 718	$ 1,429,252	$ 1,576	$ (795,959)	$ 0

Balance Sheet Accounts - Finite-Lived Intangible Assets, Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
2026	$ 547
2027	705
2028	585
2029	375
2030	351
Thereafter	1,675
Total	$ 4,238

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 54,073	$ 40,875
Marketable debt securities	381,158	408,971
Marketable equity securities	112,502	47,929
Accounts receivable	29,299	60,849
Prepaid expenses and other current assets	22,789	18,977
Total current assets	599,821	577,601
Restricted cash	289	387
Marketable debt securities - long term	175,602	256,833
Property and equipment, net	53,308	59,800
Right-of-use assets	37,592	38,341
Patents, licenses, and other intangible assets, net	8,385	18,485
Other assets	498	498
Total assets	875,495	951,945
Current liabilities:
Accounts payable	10,828	16,759
Accrued expenses	34,960	19,217
Income tax payable	3,589	0
Lease liabilities	3,263	3,009
Liabilities related to the sales of future royalties	43,267	48,447
Total current liabilities	95,907	87,432
Long-term tax liabilities	2,784	9,990
Lease liabilities, net of current portion	64,735	65,338
Liabilities related to the sales of future royalties, net of current portion	76,482	115,159
Total liabilities	239,908	277,919
Commitments and contingencies
Noncontrolling interest and stockholders’ equity
Common stock, $0.01 par value: Authorized 200,000 shares Issued and outstanding 71,872 and 70,256 shares at December 31, 2025 and 2024, respectively	718	703
Additional paid-in capital	1,429,252	1,381,607
Accumulated other comprehensive income (loss)	1,576	(663)
Accumulated deficit	(795,959)	(704,036)
Total stockholders’ equity attributable to Xencor, Inc.	635,587	677,611
Noncontrolling interest	0	(3,585)
Total noncontrolling interest and stockholders’ equity	635,587	674,026
Total liabilities and stockholders’ equity	$ 875,495	$ 951,945

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2025
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company sponsors a defined-contribution plan under Section 401(k) of the Internal Revenue Code covering all full-time employees. Under the terms of the plan, eligible employees may elect to contribute a portion of their salary on a pre-tax and/or Roth basis, subject to applicable federal statutory contribution limits. Effective April 1, 2023, the Company matches 100% of the first 2.0% of participating employees’ contribution and 50% of the next 5.0%, for a maximum employer contribution of 4.5% of eligible compensation. Participants are immediately vested in their employee contributions. Employer contributions vest ratably over three years, with one-third vesting for each year of a participating employee’s service. For the years ended December 31, 2025, 2024, and 2023, the Company recorded expenses for the matching contributions under this plan of $1.6 million, $1.6 million, and $1.7 million, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Income Taxes - Unrecognized Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Unrecognized Tax Benefits [Roll Forward]
Balance at January 1	$ 8,905	$ 8,905	$ 0
Increase related to prior period tax positions	1,464	0	1,054
Decrease related to prior period tax positions	(6,653)	0	0
Increase related to current year tax positions	1,234	0	7,851
Decrease related to settlements with tax authorities	(353)	0	0
Gross unrecognized tax benefits at December 31	$ 4,597	$ 8,905	$ 8,905

Stockholders’ Equity

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Stockholders’ Equity

The following table summarizes the Company’s shares of common stock and preferred stock:


		Shares
	Par Value	Authorized	Issued	Outstanding

As of December 31, 2025
Common Stock	$0.01	200,000,000	71,871,975	71,871,975
Preferred Stock	$0.01	10,000,000	—	—

As of December 31, 2024
Common Stock	$0.01	200,000,000	70,256,108	70,256,108
Preferred Stock	$0.01	10,000,000	—	—

On February 27, 2023, the Company filed an automatic universal shelf registration statement on Form S-3 (File No. 333-270030) as a well-known seasoned issuer as defined in Rule 405 under the Securities Act of 1933, as amended, which became effective upon filing (the “Shelf Registration Statement”). The Shelf Registration Statement allows the Company to offer an indeterminate amount of securities, including equity securities, debt securities, warrants, rights, units and depositary shares, from time to time as described in the Shelf Registration Statement. The specific terms of any offering under the Shelf Registration Statement will be established at the time of such offering. The Shelf Registration Statement will expire on February 27, 2026. The Company plans to file a new shelf registration statement on Form S-3 with the SEC simultaneously with, or promptly after, the filing of this Annual Report on Form 10-K, which would replace the Shelf Registration Statement.

On February 27, 2023, the Company entered into a sales agreement (the “Sales Agreement”) with SVB Securities LLC (the “Agent”) pursuant to which the Company may offer and sell, from time to time, through the Agent (the “ATM Offering”), shares of its common stock having an aggregate offering price of up to $200.0 million (the “ATM Shares”). Any ATM Shares offered and sold in the ATM Offering are to be issued pursuant to the Shelf Registration Statement and the 424(b) prospectus supplement relating to the ATM Offering dated February 27, 2023 (the “ATM Prospectus”). From the date of the ATM Prospectus through December 31, 2025, no shares of the Company’s common stock were sold pursuant to the ATM Offering and, as of December 31, 2025, the Company may sell shares of its common stock for remaining gross proceeds of up to $200.0 million from time to time pursuant to the ATM Prospectus.

On September 12, 2024, the Company completed an underwritten public offering pursuant to the Company’s Shelf Registration Statement. In the offering, the Company sold pre-funded warrants to purchase up to 3,088,888 shares of common stock at a purchase price of $17.99 per pre-funded warrant, for an aggregate value of approximately $55.6 million. The pre-funded warrants were classified as equity in the Company’s consolidated financial statements. In January 2026, pre-funded warrants to purchase up to 1,388,888 shares of common stock were exercised on a cashless basis, resulting in the issuance of shares of common stock. The warrants had a nominal exercise price of $0.01 per share. The exercise resulted in nominal proceeds to the Company and did not have a material impact on the Company’s financial statements.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2025
Audit Information [Abstract]
Auditor Firm ID	185
Auditor Name	KPMG LLP
Auditor Location	San Diego, California

Liabilities Related to the Sales of Future Royalties - Narrative (Details) - Royalties - USD ($) $ in Millions				36 Months Ended
	Jan. 01, 2029	Nov. 03, 2023	Jul. 01, 2023	Dec. 31, 2028	Dec. 31, 2025
Alexion \| Option and License Agreement
Sales of Future Royalties [Line Items]
Proceeds from upfront payment		$ 192.5
Royalty liability, maximum annual receivable for specific sales		18.0
Collaboration agreement, effective rate					24.20%
Alexion \| Option and License Agreement \| Forecast
Sales of Future Royalties [Line Items]
Contract with customer, percent of receivable rights				100.00%
Expected royalty interest payments	$ 12.0			$ 35.0
MorphoSys \| Collaboration and License Agreement
Sales of Future Royalties [Line Items]
Proceeds from upfront payment		$ 22.5
Expected royalty interest payments			$ 29.3
Interest rate					17.30%

Collaboration and Licensing Agreements - Gilead Sciences, Inc. (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($) Integer	Jan. 01, 2020 USD ($)
Collaboration research and licensing agreements
Collaborations, milestones, and royalties	$ 125,576	$ 110,493	$ 174,615
Gilead
Collaboration research and licensing agreements
Collaborations, milestones, and royalties	$ 0	$ 0	6,000
Gilead \| Technology License Agreement
Collaboration research and licensing agreements
Collaborations, milestones, and royalties			$ 6,000
Number of licensed products \| Integer			2
Revenue recognition milestone method pending				$ 128,000

- Definition

+ References

+ Details

Collaboration and Licensing Agreements - Vega Therapeutics (Details) - Vega - Technology License Agreement $ in Millions	1 Months Ended
	Oct. 31, 2021 USD ($)
Collaboration research and licensing agreements
Revenue recognized	$ 0.5
Revenue recognition milestone method pending	$ 30.0

Leases - Undiscounted Cash Flows (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Leases [Abstract]
2026	$ 7,816
2027	9,759
2028	9,276
2029	9,531
2030	9,794
Thereafter	48,436
Total	94,612
Less: Imputed interest	(26,614)
Total operating lease liabilities (includes current portion)	$ 67,998

Collaboration and Licensing Agreements - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Collaboration research and licensing agreements
Total	$ 125,576	$ 110,493	$ 174,615
License
Collaboration research and licensing agreements
Total	0	8,500	0
Milestone
Collaboration research and licensing agreements
Total	45,300	34,500	88,500
Royalties
Collaboration research and licensing agreements
Total	80,276	67,493	55,795
Collaboration
Collaboration research and licensing agreements
Total	$ 0	$ 0	$ 30,320

- Definition

+ References

+ Details

Balance Sheet Accounts

12 Months Ended

Dec. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Balance Sheet Accounts

Property and Equipment

The following table summarizes the Company’s major classes of property and equipment:


	December 31,
	2025		2024
	(in thousands)
Lab equipment	$	43,749	$	40,937
Computer, software and office equipment	2,003		2,131
Furniture and fixtures	128		128
Leasehold improvements	52,270		51,566
Construction in progress	6,630		7,217
Total gross carrying amount	104,780		101,979
Less: accumulated depreciation and amortization	(51,472)		(42,179)
Property and equipment, net	$	53,308	$	59,800

Depreciation and amortization expense for property and equipment for the years ended December 31, 2025, 2024 and 2023 was $9.6 million, $10.8 million and $10.1 million, respectively.

Patents, Licenses, and Other Intangible Assets

The following table summarizes the Company’s patents, licenses, and other intangible assets:


	December 31,
	2025		2024
	(in thousands)
Patents	$	10,784	$	16,854
Licenses and other intangible assets	972		2,430
Total finite-lived assets	11,756		19,284
Indefinite-lived assets	4,147		10,795
Total gross carrying amount	15,903		30,079
Accumulated amortization	(7,518)		(11,594)
Total patents, licenses, and other intangible assets, net	$	8,385	$	18,485

Amortization expense was $0.9 million, $1.3 million, and $1.3 million for the years ended December 31, 2025, 2024, and 2023, respectively. None of these assets with definite useful lives are anticipated to have a residual value.

Patents, licenses and other intangible assets are reviewed annually for impairment and more frequently if potential impairment indicators exist. The Company recorded the asset impairment charges of $9.2 million during the year ended December 31, 2025, related to its decision to pause further development of certain programs and prioritize resources toward advancing other pipeline programs. As a result, associated patents related to the paused programs were impaired.

The following table presents the estimated future amortization expense related to definite-lived assets as of December 31, 2025:


	Amortization Expense
Year ending December 31,	(in thousands)
2026	$	547
2027	705
2028	585
2029	375
2030	351
Thereafter	1,675
Total	$	4,238

Accrued Expense

Accrued expenses consist of the following:


	December 31,
	2025		2024
	(in thousands)
Accrued R&D expenses	$	12,858	$	2,324

Accrued payroll and benefits	20,209		14,849
Other	1,893		2,044
Total accrued expenses	$	34,960	$	19,217

Collaboration and Licensing Agreements

12 Months Ended

Dec. 31, 2025

Collaboration and Licensing Agreements

Collaboration and Licensing Agreements

The following table provides a summary of revenue recognized:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Alexion	$	70,070	$	58,213	$	64,891
Amgen	—		30,000		—


Gilead	—		—		6,000
Janssen	—		—		77,820
Incyte	51,696		8,693		8,700
Mabgeek	1,800		1,500		—
Novartis	—		4,000		—
Omeros	—		—		5,000
Vega	—		500		—
Vir Bio	2,010		587		2,204

Zenas	—		—		10,000
Third Party Licensee	—		7,000		—
Total	$	125,576	$	110,493	$	174,615

The following table presents a disaggregation of revenue recognized during the periods indicated:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
License	$	—	$	8,500	$	—
Milestone	45,300		34,500		88,500
Royalties	80,276		67,493		55,795
Collaboration	—		—		30,320
Total	$	125,576	$	110,493	$	174,615

The following table summarizes the balance of receivables and contract liabilities related to the Company’s collaboration and license agreements:


	December 31,
	2025		2024
	(in thousands)
Receivables included in accounts receivable	$	29,299	$	53,546
Contract liabilities included in deferred revenue	$	—	$	—

Alexion Pharmaceuticals, Inc. (“Alexion”)

In January 2013, the Company entered into an Option and License Agreement (the “Alexion Agreement”) with Alexion, which was acquired by AstraZeneca in 2021. Under the terms of the Alexion Agreement, the Company granted to Alexion an exclusive research license, with limited sublicensing rights, to make and use the Company’s Xtend technology to evaluate and advance compounds. Alexion exercised its rights to one target program, ALXN1210, which is now marketed as Ultomiris®.

Under the Alexion Agreement, no further milestone payments are expected. The Company is entitled to receive royalties in the low single digits based on a percentage of net sales of Ultomiris sold by Alexion, its affiliates or its sublicensees. Alexion’s royalty obligations apply on a product-by-product and country-by-country basis and continue until the expiration of the last-to-expire valid licensed patent covering the applicable product in such country. On December 9, 2025, a patent term extension related to the Xtend™ Fc domain for antibodies targeting C5 was announced, extending the expected royalty term for Ultomiris® net sales into December 2028 in the United States.

On November 3, 2023, the Company entered into a royalty sale agreement (the “Ultomiris Royalty Sale Agreement”) with OCM Life Sciences Portfolio LP (“OMERS”), under which OMERS acquired the rights to certain royalties associated with the existing license relating to Ultomiris.

Under the Alexion Agreement, the Company recognized non-cash royalty revenue of $70.1 million, $58.2 million, and $12.5 million for the years ended December 31, 2025, 2024 and 2023, respectively, and cash royalty revenue of $32.4 million and milestone revenue of $20.0 million in 2023. As of December 31, 2025, the Company recorded $19.7 million in accounts receivable based on estimated royalties due under the arrangement. Payment of this receivable will be made directly to OMERS. See Note 6.

Amgen Inc. (“Amgen”)

In September 2015, the Company entered into a Research and License Agreement (the “Amgen Agreement”) with Amgen to develop and commercialize bispecific antibody product candidates using the Company’s proprietary XmAb® bispecific Fc technology.

In December 2024, Amgen initiated a Phase 3 clinical study of xaluritamig, which triggered a $30.0 million milestone payment received by the Company in January 2025. Under the Amgen Agreement, the Company is eligible to receive up to $225.0 million in regulatory and sales milestone payments related to the xaluritamig program, as well as royalties on global net sales of approved products.

There were no contract assets and liabilities recorded as of December 31, 2025.

Gilead Sciences, Inc. (“Gilead”)

In January 2020, the Company entered into a Technology License Agreement (the “Gilead Agreement”) with Gilead, pursuant to which the Company granted Gilead an exclusive license to its Cytotoxic Fc and Xtend Fc technologies for an initial identified antibody and options for up to three additional antibodies directed to the same molecular target. Gilead is responsible for all development and commercialization activities for all target candidates.

The Company recognized $6.0 million in milestone revenue during fiscal 2023 upon the initiation of the first Phase 2 clinical trial for two licensed products. Under the Gilead Agreement, the Company received an upfront payment and is eligible to receive up to $128.0 million in development, regulatory, and sales milestone payments for each product incorporating the selected antibodies, as well as royalties in the low-single-digit percentage range on net sales of approved products.

There were no contract assets and liabilities recorded as of December 31, 2025.

Janssen Biotech, Inc., a Johnson & Johnson Company (“Janssen”)

J&J Agreement

In November 2020, the Company entered into a Collaboration and License Agreement (the “J&J Agreement”) with Janssen, to discover and develop novel CD28 bispecific antibody product candidates for the treatment of prostate cancer using the Company’s XmAb bispecific antibody technology. Under the J&J Agreement, the parties conducted joint research activities, with Janssen retaining exclusive worldwide rights to develop and commercialize licensed products identified from the collaboration. The Company satisfied its research performance obligations under the J&J Agreement in 2021.

Under the J&J Agreement, the Company received an upfront payment and is eligible to receive up to $640.0 million in development, regulatory and sales milestone payments, as well as royalties on net sales of approved products ranging from the high-single-digit to low-double-digit percentages.

Second J&J Agreement

In October 2021, the Company entered into a second collaboration and license agreement with J&J (the “Second J&J Agreement”), pursuant to which Janssen received an exclusive worldwide license to develop, manufacture, and commercialize plamotamab, the Company’s CD20 x CD3 bispecific antibody candidate. The parties also agreed to collaborate on additional CD28 bispecific antibody research, with Janssen holding exclusive development and commercialization rights, subject to certain opt-in rights by the Company.

Under the Second J&J Agreement, the Company received an upfront payment and is eligible to receive up to $636.3 million in development, regulatory and sales milestone payments, as well as tiered royalties on net sales of approved products. The Company completed its research performance obligations under the Second J&J Agreement in December

2023, and Janssen selected three CD20 x CD3 bispecific antibody candidates to conduct further development. In June 2024, Janssen notified the Company of its decision to terminate its rights to plamotamab.

The Company recognized $77.8 million of revenue related to the two J&J agreements for the year ended December 31, 2023. There were no contract assets or contract liabilities related to the J&J agreements as of December 31, 2025.

Incyte Corporation (“Incyte”)

In June 2010, the Company entered into a Collaboration and License Agreement (the “MorphoSys Agreement”) with MorphoSys AG (“MorphoSys”). Under the MorphoSys Agreement, the Company granted MorphoSys an exclusive worldwide license to its patents and know-how to research, develop and commercialize the XmAb5574 product candidate (subsequently renamed MOR208 and tafasitamab) with the right to sublicense under certain conditions. In February 2024, Incyte assumed all of MorphoSys’ right, title and interest in the MorphoSys Agreement and acquired exclusive global development and commercialization rights to tafasitamab. If certain developmental, regulatory and sales milestones are achieved, the Company is eligible to receive future milestone payments and royalties from Incyte.

In February 2025, the United States Food and Drug Administration (“FDA”) accepted Incyte’s submission of a supplemental biologics license application, triggering a $12.5 million milestone payment to the Company, and approved the application in June 2025, triggering an additional $25.0 million milestone payment to the Company. Both milestone payments were received by the Company in 2025. In addition, Incyte dosed two patients in a Phase 2 study on December 29, 2025, one patient with immune thrombocytopenia and one patient with autoimmune hemolytic anemia, triggering a $4.0 million milestone payment to the Company which was paid in January 2026.

Under the MorphoSys Agreement, the Company is eligible to receive up to $195.0 million in developmental, regulatory and sales milestones, as well as royalties on net sales, subject to the terms and conditions of the agreement.

On November 3, 2023, the Company entered into a royalty sale agreement (the “Monjuvi Royalty Sale Agreement”) with OMERS, under which OMERS acquired the rights to certain royalties associated with the existing license relating to Incyte. The $41.5 million of milestone payments recognized by the Company in 2025 are not subject to the Monjuvi Royalty Sale Agreement.

Under the MorphoSys Agreement, the Company recognized non-cash royalty revenue of $10.2 million, $8.7 million, and $2.1 million for the years ended December 31, 2025, 2024 and 2023, respectively, and cash royalty revenue of $6.6 million in 2023. As of December 31, 2025, the Company recorded $3.0 million in accounts receivable based on estimated royalties due under the arrangement. Payment of this receivable will be made directly to OMERS. See Note 6.

Hunan Mabgeek Biotech Co., Ltd., formerly known as, Shanghai Mabgeek Biotech Co., Ltd. (“Mabgeek”)

On December 22, 2023, the Company entered into a Technology License Agreement with Mabgeek. On June 21, 2024, the parties entered into Amendment No. 1 to the Technology License Agreement (as amended, the “Mabgeek Agreement”). Under the Mabgeek Agreement, the Company received an upfront payment of $1.5 million, which was recognized as revenue, and is eligible to receive royalties in the low single digits on net sales of approved products.

The Company evaluated the Mabgeek Agreement and determined that it contains a single performance obligation—access to a non-exclusive license to certain Company patents, which was transferred to Mabgeek in June 2024. Mabgeek’s Phase 3 study achieved the milestone of database lock in Mainland China on November 20, 2025, triggering a $1.8 million milestone payment, which will be received in the first quarter of 2026.

Under the Mabgeek Agreement, the Company is eligible to receive up to $10.1 million in regulatory and sales milestone payments, as well as royalties on net sales, subject to the terms and conditions of the agreement. As of December 31, 2025, the Company recorded $1.8 million in accounts receivable and no liabilities.

Novartis Institute for Biomedical Research, Inc. (“Novartis”)

In June 2016, the Company entered into a Collaboration and License Agreement (the “Novartis Agreement”) with Novartis to develop and commercialize bispecific and other Fc-engineered antibody product candidates using the Company’s proprietary XmAb® technologies.

In June 2021, Novartis selected an Fc product candidate and assumed full responsibility for its development and commercialization. In 2024, Novartis initiated a Phase 2 clinical study for the Fc product candidate, resulting in $4.0 million of revenue recognized under the Novartis Agreement.

Under the Novartis Agreement, the Company is eligible to receive up to $309.0 million in development, clinical, and sales milestone payments, as well as royalties on net sales of approved products.

As of December 31, 2025, there were no contract assets or liabilities related to the Novartis Agreement.

Novo Nordisk Health Care AG (“Novo Nordisk”)

In August 2020, the Company entered into a Technology License Agreement (the “Omeros Agreement”) with Omeros Corporation (“Omeros”), pursuant to which the Company granted Omeros rights to use the Company’s Xtend Fc technology for certain antibody product candidates, including zaltenibart. In November 2025, Novo Nordisk acquired exclusive global development and commercialization rights to zaltenibart from Omeros, and the Omeros Agreement was assigned to Novo Nordisk. Under the Omeros Agreement, Novo Nordisk is responsible for all development and commercialization activities related to zaltenibart.

In 2023, Omeros advanced zaltenibart into a Phase 2 clinical study, resulting in $5.0 million of revenue under the Omeros Agreement. Under the Omeros Agreement, the Company is eligible to receive up to $60.0 million in development, clinical, and sales milestone payments, as well as royalties on net sales.

There were no contract assets or contract liabilities recorded as of December 31, 2025.

Vega Therapeutics, Inc. (“Vega”)

In October 2021, the Company entered into a Technology License Agreement (the “Vega Agreement”) with Vega, granting Vega a non-exclusive license to its Xtend Fc technology. In March 2024, Vega initiated a Phase 1 study, resulting in $0.5 million of revenue under the Vega Agreement.

Under the Vega Agreement, the Company is eligible to receive up to $30.0 million in developmental, regulatory and sales milestones, as well as royalties on net sales, subject to the terms and conditions of the agreement. There were no contract assets or contract liabilities related to the Vega Agreement as of December 31, 2025.

Vir Biotechnology, Inc. (“Vir Bio”)

In 2019, the Company entered into a Patent License Agreement (the “Vir Bio Agreement”) with Vir Bio, granting a non-exclusive license to its Xtend technology for up to two targets, including that of tobevibart. In March 2025, Vir Bio initiated a Phase 3 study for tobevibart, triggering a $2.0 million milestone payment to the Company, which was paid in the second quarter of 2025.

In March 2020, the Company entered into a second Patent License Agreement (the “Second Vir Bio Agreement”) with Vir Bio, granting a non-exclusive license to its Xtend technology to extend the half-life of novel antibodies Vir Bio developed as potential treatments for patients with COVID-19, including sotrovimab. Under the terms of the Second Vir Bio Agreement, Vir Bio is responsible for all research, development, regulatory and commercial activities for the antibodies, and the Company is eligible to receive royalties on the net sales of approved products in the mid-single digit percentage range. Vir Bio and its marketing partner, GSK, began recording sales for sotrovimab beginning in June 2021. In March 2022, the FDA deauthorized sotrovimab’s use in all U.S. regions due to increases in the proportion of COVID-19 cases caused by the Omicron BA.2 subvariant.

The Company recognized a nominal amount of royalty revenue for the year ended December 31, 2025, and $0.6 million and $2.2 million for the years ended December 31, 2024 and 2023, respectively. Under the Vir Bio Agreement, the Company is eligible to receive up to $65.0 million in developmental, regulatory and sales milestones, as well as royalties on net sales, subject to the terms and conditions of the agreement.

There were no contract assets or contract liabilities related to the Vir Bio Agreement as of December 31, 2025.

Zenas BioPharma, Inc. (“Zenas”)

In November 2020, the Company entered into a License Agreement (the “Zenas Agreement”) with Zenas, pursuant to which the Company granted Zenas exclusive worldwide rights to develop and commercialize three preclinical-stage Fc-engineered drug candidates.

In November 2021, the Company entered into a second license agreement (the “Second Zenas Agreement”), pursuant to which the Company granted Zenas exclusive worldwide rights to develop and commercialize obexelimab (XmAb5871). The Company satisfied its performance obligations under the Zenas agreements in 2021.

In 2023, Zenas initiated a Phase 3 clinical study of obexelimab, which triggered an equity-based milestone payment. The Company recognized $10.0 million of milestone revenue in 2023, representing the fair value of the equity shares received at the date of issuance. Under the two Zenas agreements, the Company received equity-based consideration and is eligible to receive up to $460.0 million in regulatory and sales milestones, as well as royalties on net sales of approved products in the mid-single-digit to mid-teen percentage range.

There were no contract assets or contract liabilities recorded as of December 31, 2025.

Third-Party License

In May 2024, the Company entered into a Patent License Agreement with a third-party licensee. The Company satisfied its performance obligation under the agreement, resulting in $7.0 million of revenue. There is no further obligation under this agreement.

Leases - Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Leases [Abstract]
Operating lease assets	$ 37,592	$ 38,341
Current operating lease liabilities	3,263	3,009
Non-current operating lease liabilities	$ 64,735	$ 65,338

Segment Reporting

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment Reporting

The Company operates as a single reportable segment focused on discovering and developing engineered antibody therapeutics to treat patients with cancer and autoimmune diseases who have unmet medical needs.

The Company’s Chief Executive Officer (“CEO”) serves as the CODM. The CODM evaluates performance, allocates resources, and conducts planning and forecasting on a consolidated basis using financial information as presented in the Company’s consolidated statements of operations and comprehensive loss. In addition, the CODM reviews research and development expenses by program. Managing and allocating resources at the corporate level enables the Company’s CEO to assess the overall level of resources available and to deploy those resources in alignment with the Company’s long-term, corporate-wide strategic objectives.


	Year Ended December 31,
	2025		2024 (2)		2023 (2)
	(in thousands)
Revenues:
License	$	—	$	8,500	$	—
Milestone	45,300		34,500		88,500
Royalties	80,276		67,493		55,795
Collaboration	—		—		30,320
Total revenues	125,576		110,493		174,615
Less:
Research and development:
XmAb819 (ENPP3 x CD3)	(23,119)		(10,735)		(6,808)
XmAb657 (CD19 x CD3)	(13,767)		(2,644)		—
XmAb942 (Xtend TL1A)	(13,419)		(18,654)		(946)
XmAb541 (CLDN6 x CD3)	(12,742)		(4,068)		(8,237)
XmAb412 (TL1A x IL-23p19)	(8,064)		—		—
Plamotamab (CD20 x CD3)	(7,229)		(6,015)		(1,787)
XmAb808 (B7-H3 x CD28)	(5,888)		(8,210)		(7,168)
Other programs including research and early stage	(18,229)		(28,037)		(40,407)
Wind down costs of terminated programs	(17,224)		(27,420)		(54,328)
Internal research and development expenses	(94,783)		(91,948)		(99,401)
Research and development stock based compensation	(24,970)		(29,955)		(34,516)
General and administrative	(63,644)		(61,215)		(53,379)
Other income (expense), net (1)	87,869		(56,515)		12,728
Income tax expense	(2,504)		(1,617)		(13,662)
Net loss including noncontrolling interest	$	(92,137)	$	(236,540)	$	(133,296)

(1) Other income (expense), net, included interest income, interest expense, gain/loss on marketable equity securities and asset impairment charges.

For the years ended December 31, 2025, 2024, and 2023, the Company’s total revenues were derived from collaboration and licensing agreements and were reported within the Company’s single operating segment. Revenues are attributed to geographic areas based on the location of the Company’s customers. For the years ended December 31, 2025, 2024, and 2023, substantially all of the Company’s revenues were generated from customers located in the United States, and substantially all of the Company’s long-lived assets were located in the United States. The measure of segment assets is reported on the consolidated balance sheets as total consolidated assets.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-21

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-21

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-31

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-15

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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+ Details

Organization and Summary of Significant Accounting Policies - Segment Information (Details)	12 Months Ended
	Dec. 31, 2025 segment
Accounting Policies [Abstract]
Number of operating segments	1

Collaboration and Licensing Agreements - Receivables and Contract Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Receivables included in accounts receivable	$ 29,299	$ 53,546
Contract liabilities included in deferred revenue	$ 0	$ 0

Liabilities Related to the Sales of Future Royalties - Debt of Future Royalties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Sale of Future Royalty [Roll Forward]
Beginning balance	$ 163,606	$ 189,483
Royalties owed to OMERS	0	834
Royalties paid to OMERS	(75,778)	(63,304)
Non-cash interest expense recognized	31,921	36,593
Ending balance	119,749	163,606
Current liabilities	43,267	48,447
Long-term liabilities	76,482	115,159
Total	$ 119,749	$ 163,606

Segment Reporting - Narrative (Details)	12 Months Ended
Segment Reporting - Narrative (Details)	Dec. 31, 2025 segment
Segment Reporting [Abstract]
Number of reportable segments	1

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities
Net loss including noncontrolling interest	$ (92,137)	$ (236,540)	$ (133,296)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	10,512	12,107	11,498
Accretion of discount on marketable debt securities, net	(3,481)	(16,044)	(13,635)
Stock-based compensation	43,227	53,281	53,755
Gain on sale of marketable securities, net	(14,388)	(37)	0
Change in fair value of marketable equity securities	(87,126)	31,422	395
Asset impairment charges	9,169	20,430	0
Non-cash royalty revenue related to the sale of future royalties	(80,266)	(66,906)	(14,575)
Non-cash interest expense on liabilities related to the sale of future royalties	31,921	36,593	6,153
Equity received in connection with license agreement	0	0	(10,000)
Abandonment of capitalized intangibles	0	2,329	1,267
Loss on disposal of assets	0	1,577	1,379
Changes in operating assets and liabilities:
Accounts receivable	28,734	(32,673)	19,833
Interest receivable from marketable debt securities	2,622	(3,441)	(1,028)
Prepaid expenses and other assets	9,441	159	5,103
Accounts payable	(3,953)	2,845	3,826
Accrued expenses	13,796	(4,347)	4,836
Income taxes	3,589	(4,484)	13,633
Operating lease, net	400	1,541	3,250
Deferred revenue	0	0	(30,320)
Other assets and liabilities, net	(7,177)	0	0
Net cash used in operating activities	(135,117)	(202,188)	(77,926)
Cash flows from investing activities
Purchase of marketable debt securities	(298,895)	(595,054)	(782,905)
Purchase of property and equipment	(3,150)	(6,097)	(18,448)
Purchase of patents	0	(3,415)	(2,803)
Proceeds from sales of marketable equity securities	36,941	6,640	0
Proceeds from sales and maturities of marketable debt securities	405,089	590,054	693,090
Proceeds from sale of property and equipment	0	0	1
Net cash provided by (used in) investing activities	139,985	(7,872)	(111,065)
Cash flows from financing activities
Proceeds from the exercises of stock options	8,667	6,313	3,412
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	1,290	1,660	1,977
Proceeds from issuance of common stock and pre-funded warrants	0	201,256	0
Common stock and pre-funded warrants issuance costs	0	(12,077)	0
Proceeds from the sale of future royalties	0	0	183,330
Proceeds from noncontrolling interest	0	0	500
Cash paid to acquire noncontrolling interest	(1,725)	0	0
Net cash provided by financing activities	8,232	197,152	189,219
Net increase (decrease) in cash, cash equivalents, and restricted cash	13,100	(12,908)	228
Cash, cash equivalents, and restricted cash, beginning of period	41,262	54,170	53,942
Cash, cash equivalents, and restricted cash, end of period	54,362	41,262	54,170
Supplemental disclosure of cash flow information
Interest paid	5	33	22
Income taxes paid	$ 7,312	$ 6,100	$ 0

Liabilities Related to the Sales of Future Royalties (Tables)

12 Months Ended

Dec. 31, 2025

Receivables [Abstract]

Schedule of Debt of Future Royalties

The following table presents the activities with respect to the liabilities related to the sales of future royalties:


	December 31,
	2025		2024
	(in thousands)
Beginning balance	$	163,606	189,483
Royalties owed to OMERS	—		834
Royalties paid to OMERS	(75,778)		(63,304)
Non-cash interest expense recognized	31,921		36,593
Ending balance	$	119,749	$	163,606

Current liabilities	43,267		48,447
Long-term liabilities	76,482		115,159
Total	$	119,749	$	163,606

Cash Equivalents, Marketable Debt and Equity Securities - Maturities of Marketable Securities (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Amortized Cost
Mature in one year or less	$ 380,256
Mature within two years	174,918
Amortized Cost	555,174
Estimated Fair Value
Mature in one year or less	381,158
Mature within two years	175,602
Marketable debt securities	$ 556,760

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481830/320-10-45-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

Collaboration and Licensing Agreements - Zenas BioPharma, Inc. (Details) - Zenas BioPharma, Inc. - Potential Milestones - License Agreement - USD ($) $ in Millions	Dec. 31, 2023	Nov. 30, 2020
Collaboration research and licensing agreements
Revenue recognition milestone method pending		$ 460.0
Preferred Stock
Collaboration research and licensing agreements
Equity shares estimated fair value	$ 10.0

Net Loss Per Share

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Net Loss Per Share

The following table presents the computation of basic and diluted net loss per share.


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Numerator:
Net loss attributable to Xencor, Inc.	$	(91,923)	$	(232,618)	$	(133,133)
Denominator:
Weighted-average basic shares outstanding	74,239		65,041		60,503
Effect of dilutive securities	—		—		—
Weighted-average diluted shares outstanding	74,239		65,041		60,503

Basic and diluted net loss per share	$	(1.24)	$	(3.58)	$	(2.20)

All outstanding options and RSUs were excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive. The following table sets forth the potentially dilutive securities calculated as if the Company was in a net income position for the periods presented.


	Year Ended December 31,
	2025	2024	2023
Options	5,108	376,441	868,085
Restricted stock units	240,205	269,847	213,853

Total	245,313	646,288	1,081,938

Collaboration and Licensing Agreements - Vir Biotechnology, Inc. (Details) - Vir Biotechnology, Inc. - Patent License Agreement	1 Months Ended	12 Months Ended
	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2019 USD ($) target
Collaboration research and licensing agreements
Number of different target programs \| target					2
Revenue recognized	$ 2,000,000.0
Revenue recognition milestone method pending					$ 65,000,000.0
Royalties
Collaboration research and licensing agreements
Revenue recognized		$ 0	$ 600,000	$ 2,200,000

Organization and Summary of Significant Accounting Policies - Restricted Cash (Details) $ in Millions	Dec. 31, 2025 USD ($)
Accounting Policies [Abstract]
Letter of credit outstanding	$ 0.3

Cash Equivalents, Marketable Debt and Equity Securities - Equity Securities with Readily Determinable Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Equity Securities
Marketable equity securities	$ 112,502	$ 47,929
Common Stock
Equity Securities
Marketable equity securities	112,502	47,929
INmune Bio, Inc. \| Common Stock
Equity Securities
Marketable equity securities	0	8,805
Viridian Therapeutics, Inc. \| Common Stock
Equity Securities
Marketable equity securities	0	13,748
Zenas BioPharma, Inc. \| Common Stock
Equity Securities
Marketable equity securities	$ 112,502	$ 25,376

Balance Sheet Accounts - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation and amortization expense	$ 9.6	$ 10.8	$ 10.1
Amortization of intangible assets	0.9	$ 1.3	$ 1.3
Impairment of intangible assets	$ 9.2
Impairment, Intangible Asset, Statement of Income or Comprehensive Income [Extensible Enumeration]	Asset impairment charges

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-6

+ Details

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2025

Equity [Abstract]

Schedule of Basic and Diluted Net Loss Per Common Share

The following table presents the computation of basic and diluted net loss per share.


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Numerator:
Net loss attributable to Xencor, Inc.	$	(91,923)	$	(232,618)	$	(133,133)
Denominator:
Weighted-average basic shares outstanding	74,239		65,041		60,503
Effect of dilutive securities	—		—		—
Weighted-average diluted shares outstanding	74,239		65,041		60,503

Basic and diluted net loss per share	$	(1.24)	$	(3.58)	$	(2.20)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following table sets forth the potentially dilutive securities calculated as if the Company was in a net income position for the periods presented.


	Year Ended December 31,
	2025	2024	2023
Options	5,108	376,441	868,085
Restricted stock units	240,205	269,847	213,853

Total	245,313	646,288	1,081,938

Balance Sheet Accounts - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued R&D expenses	$ 12,858	$ 2,324
Accrued payroll and benefits	20,209	14,849
Other	1,893	2,044
Total accrued expenses	$ 34,960	$ 19,217

Leases - Narrative (Details) $ in Millions		1 Months Ended
Leases - Narrative (Details) $ in Millions	Aug. 08, 2025 USD ($)	Jun. 30, 2021 phase	Sep. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)	Aug. 31, 2022 USD ($)	Aug. 01, 2022 USD ($)
Lessee, Lease, Description [Line Items]
Lease, renewal term				5 years
Lease expense	$ 0.9
Letter of Credit
Lessee, Lease, Description [Line Items]
Letter of credit amount				$ 0.4
Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Phases of lease term \| phase		2
Improvement allowance					$ 5.0	$ 17.0
Pasadena, CA - office and laboratory space \| Forecast
Lessee, Lease, Description [Line Items]
Improvement allowance			$ 3.3

Collaboration and Licensing Agreements - Hunan Mabgeek Biotech Co., Ltd. fka Shanghai Mabgeek Biotech Co., Ltd. (Details) - USD ($) $ in Thousands	Nov. 20, 2025	Dec. 22, 2023	Dec. 31, 2025	Dec. 31, 2024
Collaboration research and licensing agreements
Accounts receivable			$ 29,299	$ 60,849
Mabgeek \| Technology License Agreement
Collaboration research and licensing agreements
Nonrefundable upfront payment		$ 1,500
Proceeds from milestone payments	$ 1,800
Revenue recognition milestone method pending		$ 10,100
Accounts receivable			$ 1,800

Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

Share-Based Payment Arrangement, Activity

The following table presents a summary of awards outstanding:


	As of December 31, 2025
	2013 Plan	2023 Plan	Total
Stock options	8,625,426	4,331,166	12,956,592
RSUs	215,336	1,766,009	1,981,345
	8,840,762	6,097,175	14,937,937

Schedule of Total Employee, Director and Non-Employee Stock-Based Compensation Expense Recognized

The following table summarizes stock-based compensation expenses included in operating expenses:


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
General and administrative	$	18,257	$	23,326	$	19,239
Research and development	24,970		29,955		34,516
	$	43,227	$	53,281	$	53,755


	Year Ended December 31,
	2025		2024		2023
	(in thousands)
Stock options	$	22,768	$	31,147	$	29,345
RSUs	19,594		21,276		23,167
ESPP	865		858		1,243
	$	43,227	$	53,281	$	53,755

Schedule of Stock Option Activity

The following table presents a summary of the stock option activity for the year ended December 31, 2025:


	Number of Shares Subject to Outstanding Options	Weighted Average Exercise Price (per share)		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2024	12,370,081	$	28.59	5.9	$	10,386
Granted	2,116,680	12.99
Exercised	(644,705)	13.44
Forfeited	(885,464)	26.61
Outstanding at December 31, 2025	12,956,592	$	26.93	5.6	$	5,156
Exercisable at December 31, 2025	9,324,358	$	30.14	4.5	$	867

Schedule of Weighted Average Assumptions Used for Estimation of Fair Value of Stock Options

The following table provides the weighted-average assumptions used in the calculation of grant date per share fair values of these stock options based on the Black-Scholes option pricing model:


	Year Ended December 31,
	2025			2024			2023
Expected term (in years) (1)	6.4			6.4			6.1
Expected volatility (2)	51.2		%	50.2		%	50.5		%
Risk-free interest rate (3)	4.1		%	4.2		%	4.2		%
Expected dividend yield (4)	—		%	—		%	—		%
Underlying stock price	$	12.99		$	22.31		$	30.02

(1) The computation of expected term was determined based on the option holders’ past exercise patterns.

(2) Volatility is estimated based on volatility average of the Company’s common stock price.

(3) The risk-free interest rate is based on that of the U.S. Treasury yields with equivalent terms in effect at the time of the grant.

(4) The dividend yield is zero as the Company currently does not pay a dividend.

The following table provides the assumptions used in the calculation of grant date fair values of these shares issued under the Company’s ESPP based on the Black-Scholes option pricing model:


	Year Ended December 31,
	2025		2024		2023
Expected term (in years) (1)	0.5 - 2.0		0.5 - 2.0		0.5 - 2.0
Expected volatility (2)	42.97% - 73.25%		42.97% - 54.62%		38.24% - 55.72%
Risk-free interest rate (3)	4.22% - 5.40%		4.22% - 5.40%		0.13% - 5.39%
Expected dividend yield (4)	—	%	—	%	—	%

(1) The computation of expected term was determined based on the option holders’ past exercise patterns.

(2) Volatility is estimated based on volatility average of the Company’s common stock price.

(3) The risk-free interest rate is based on that of the U.S. Treasury yields with equivalent terms in effect at the time of the grant.

(4) The dividend yield is zero as the Company currently does not pay a dividend.

Schedule of Restricted Stock Unit Activity

The following table summarizes the activity of the Company’s RSUs:


	Restricted Stock Units	Weighted Average Grant Date Fair Value (Per unit)
Outstanding as of December 31, 2024	1,783,795	$	25.52
Granted	1,204,787	13.23
Vested	(843,722)	26.53
Forfeited	(163,515)	19.46
Outstanding as of December 31, 2025	1,981,345	$	18.01

Collaboration and Licensing Agreements - Revenue by Licenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Collaboration research and licensing agreements
Total	$ 125,576	$ 110,493	$ 174,615
Alexion
Collaboration research and licensing agreements
Total	70,070	58,213	64,891
Amgen
Collaboration research and licensing agreements
Total	0	30,000	0
Gilead
Collaboration research and licensing agreements
Total	0	0	6,000
Janssen
Collaboration research and licensing agreements
Total	0	0	77,820
Incyte
Collaboration research and licensing agreements
Total	51,696	8,693	8,700
Mabgeek
Collaboration research and licensing agreements
Total	1,800	1,500	0
Novartis
Collaboration research and licensing agreements
Total	0	4,000	0
Omeros
Collaboration research and licensing agreements
Total	0	0	5,000
Vega
Collaboration research and licensing agreements
Total	0	500	0
Vir Bio
Collaboration research and licensing agreements
Total	2,010	587	2,204
Zenas BioPharma, Inc.
Collaboration research and licensing agreements
Total		0	10,000
Third Party Licensee
Collaboration research and licensing agreements
Total	$ 0	$ 7,000	$ 0