0001628280-23-016494 | 10-Q | XBRL Viewer

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Cover - shares	3 Months Ended
Cover - shares	Mar. 31, 2023	Apr. 29, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
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, 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		60,390,793
Entity Central Index Key	0001326732
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false

Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 72,394	$ 53,942
Marketable debt securities	475,922	526,689
Marketable equity securities	39,706	42,431
Accounts receivable	19,861	28,997
Prepaid expenses	22,093	23,283
Total current assets	629,976	675,342
Property and equipment, net	66,685	59,183
Patents, licenses, and other intangible assets, net	18,244	18,500
Marketable debt securities - long term	0	3,826
Marketable equity securities - long term	54,210	54,383
Notes receivable - long term	0	0
Right of use (ROU) asset	33,697	34,419
Other assets	599	613
Total assets	803,411	846,266
Current liabilities
Accounts payable	15,341	10,088
Accrued expenses	15,140	18,728
Lease liabilities	4,471	4,708
Deferred revenue	30,104	30,320
Total current liabilities	65,056	63,844
Lease liabilities, net of current portion	54,772	54,926
Total liabilities	119,828	118,770
Commitments and contingencies
Stockholders’ equity
Preferred stock, $0.01 par value: 10,000,000 authorized shares; -0- issued and outstanding shares at March 31, 2023 and December 31, 2022	0	0
Common stock, $0.01 par value: 200,000,000 authorized shares at March 31, 2023 and December 31, 2022; 60,381,600 issued and outstanding at March 31, 2023 and 59,997,713 issued and outstanding at December 31, 2022	605	601
Additional paid-in capital	1,085,651	1,072,132
Accumulated other comprehensive loss	(3,625)	(6,952)
Accumulated deficit	(399,048)	(338,285)
Total stockholders’ equity	683,583	727,496
Total liabilities and stockholders’ equity	$ 803,411	$ 846,266

Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
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
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)	60,381,600	59,997,713
Common stock, shares outstanding (in shares)	60,381,600	59,997,713

Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue
Collaborations, milestones, and royalties	$ 18,962	$ 85,495
Operating expenses
Research and development	64,379	47,756
General and administrative	13,948	11,273
Total operating expenses	78,327	59,029
Loss from operations	(59,365)	26,466
Other income (expenses)
Interest income, net	2,892	653
Other expense, net	(1,392)	(96)
Loss on equity securities, net	(2,898)	(3,429)
Total other expense, net	(1,398)	(2,872)
Net income (loss)	(60,763)	23,594
Other comprehensive income (loss)
Net unrealized gain (loss) on marketable debt securities	3,327	(5,611)
Comprehensive income (loss)	$ (57,436)	$ 17,983
Net income (loss) per share attributable to common stockholders:
Basic net income (loss) per common share (in dollars per share)	$ (1.02)	$ 0.40
Diluted net income (loss) per common share (in dollars per share)	$ (1.02)	$ 0.39
Weighted average shares used to compute net income (loss) per share attributable to common stockholders:
Basic (in shares)	59,771,674	59,407,829
Diluted (in shares)	59,771,674	61,078,494

Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021		59,355,558
Beginning balance at Dec. 31, 2021	$ 733,504	$ 595	$ 1,017,523	$ (1,510)	$ (283,104)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock awards (in shares)		36,500
Issuance of common stock upon exercise of stock awards	731	$ 0	731
Issuance of restricted stock units (in shares)		137,134
Issuance of restricted stock units	0	$ 1	(1)
Comprehensive income (loss)	17,983			(5,611)	23,594
Stock-based compensation	10,805		10,805
Ending balance (in shares) at Mar. 31, 2022		59,529,192
Ending balance at Mar. 31, 2022	763,023	$ 596	1,029,058	(7,121)	(259,510)
Beginning balance (in shares) at Dec. 31, 2022		59,997,713
Beginning balance at Dec. 31, 2022	727,496	$ 601	1,072,132	(6,952)	(338,285)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock awards (in shares)		34,388
Issuance of common stock upon exercise of stock awards	924		924
Issuance of restricted stock units (in shares)		349,499
Issuance of restricted stock units	0	$ 4	(4)
Comprehensive income (loss)	(57,436)			3,327	(60,763)
Stock-based compensation	12,599		12,599
Ending balance (in shares) at Mar. 31, 2023		60,381,600
Ending balance at Mar. 31, 2023	$ 683,583	$ 605	$ 1,085,651	$ (3,625)	$ (399,048)

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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-Topic 825
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Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net income (loss)	$ (60,763)	$ 23,594
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	2,245	2,178
Amortization of premium on marketable securities	(1,661)	543
Stock-based compensation	12,599	10,805
Abandonment of capitalized intangible assets	321	311
Change in fair value of equity securities	2,898	3,429
Loss on disposal of assets	1,379	117
Changes in operating assets and liabilities:
Accounts receivable and contract asset	9,135	(26,820)
Interest receivable from marketable debt securities	248	(251)
Prepaid expenses and other assets	1,204	906
Accounts payable	5,254	(2,096)
Accrued expenses	(3,588)	(6,831)
Lease liabilities and ROU assets	331	1,736
Deferred revenue	(216)	(1,806)
Net cash (used in) provided by operating activities	(30,614)	5,815
Cash flows from investing activities
Purchase of marketable securities	(95,228)	(88,764)
Purchase of intangible assets	(407)	(906)
Purchase of property and equipment	(10,783)	(2,089)
Proceeds from maturities and sale of marketable securities	154,562	20,000
Net cash provided by (used in) investing activities	48,144	(71,759)
Cash flows from financing activities
Proceeds from issuance of common stock upon exercise of stock awards	922	731
Net cash provided by financing activities	922	731
Net increase (decrease) in cash and cash equivalents	18,452	(65,213)
Cash and cash equivalents, beginning of period	53,942	143,480
Cash and cash equivalents, end of period	72,394	78,267
Cash paid during the period for:
Interest	7	4
Supplemental disclosures of non-cash investing activities
Unrealized gain (loss) on marketable securities	$ 3,327	$ (5,611)

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited interim financial statements for Xencor, Inc. (the Company, Xencor, we or us) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of the Company believes are necessary for a fair presentation of the periods presented. The preparation of interim financial statements requires the use of management’s estimates and assumptions that affect reported amounts of assets and liabilities at the date of the interim financial statements and the reported revenues and expenditures during the reported periods. These interim financial results are not necessarily indicative of the results expected for the full fiscal year or for any subsequent interim period. The accompanying unaudited interim financial statements and related notes should be read in conjunction with the audited financial statements and notes thereto included in the Company’s 2022 Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 24, 2023. Use of Estimates The preparation of interim financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, other comprehensive gain (loss) and the related disclosures. On an ongoing basis, management evaluates its estimates, including estimates related to its accrued clinical trial and manufacturing development expenses, stock-based compensation expense, evaluation of intangible assets, investments, leases and other assets for evidence of impairment, fair value measurements, and contingencies. Significant estimates in these interim financial statements include estimates made for royalty revenue, accrued research and development expenses, stock-based compensation expenses, intangible assets, incremental borrowing rate for right-of-use asset and lease liability, estimated standalone selling price of performance obligations, estimated time for completing delivery of performance obligations under certain arrangements, the likelihood of recognizing variable consideration, the carrying value of equity instruments without a readily determinable fair value, and recoverability of deferred tax assets. Intangible Assets The Company maintains definite-lived intangible assets related to certain capitalized costs of acquired licenses and third-party costs incurred in establishing and maintaining its intellectual property rights to its platform technologies and development candidates. These assets are amortized over their useful lives, which are estimated to be the remaining patent life or the contractual term of the license. The straight-line method is used to record amortization expense. The Company assesses its intangible assets for impairment if indicators are present or changes in circumstances suggest that impairment may exist. There was no impairment charge recorded for the three months ended March 31, 2023 and 2022. The Company capitalizes certain in-process intangible assets that are then abandoned when they are no longer pursued or used in current research activities. There was no material abandonment of in-process intangible assets for each of the three months ended March 31, 2023 and March 31, 2022. Marketable Debt and Equity Securities The Company has an investment policy that includes guidelines on acceptable investment securities, minimum credit quality, maturity parameters, and concentration and diversification. The investment policy limits the maturity of any individual security to a maximum of 36 months. The average maturity of securities in the portfolio as of March 31, 2023 is less than 12 months. The Company invests its excess cash primarily in marketable debt securities issued by investment grade institutions. The Company considers its marketable debt securities to be available-for-sale because it is not more likely than not that the Company will be required to sell the securities before recovery of the amortized cost. These assets are carried at fair value and any impairment losses and recoveries related to the underlying issuer’s credit standing are recognized within other income (expense), while non-credit related impairment losses and recoveries are recognized within accumulated other comprehensive income (loss). There were no impairment losses or recoveries recorded for the three months ended March 31, 2023 and 2022. Accrued interest on marketable debt securities is included in the marketable securities’ carrying value. Each reporting period, the Company reviews its portfolio of marketable debt securities, using both quantitative and qualitative factors, to determine if each security’s fair value has declined below its amortized cost basis. During the three months ended March 31, 2023, the Company recorded an unrealized gain of $3.3 million in its portfolio of marketable debt securities. During the three months ended March 31, 2022, the Company recorded an unrealized loss of $5.6 million. The unrealized losses are due to the changing interest rate environment and are not due to changes in the credit quality of the underlying securities. The unrealized gain is recorded in other comprehensive income (loss) for the three months ended March 31, 2023. The Company receives equity securities in connection with certain licensing transactions with its partners. These investments in equity securities are carried at fair value with changes in fair value recognized each period and reported within other income (expense). For equity securities with a readily determinable fair value, the Company remeasures these equity investments at each reporting period until such time that the investment is sold or disposed. If the Company sells an investment, any realized gain or loss on the sale of the securities will be recognized within other income (expense) in the Statements of Comprehensive Income (Loss) in the period of sale. The Company also has investments in equity securities without a readily determinable fair value, where the Company elects the measurement alternative to record the investment at its initial cost minus impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. There was no impairment charge recorded for the three months ended March 31, 2023 and 2022, in connection with equity securities without a readily determinable fair value. Recent Accounting Pronouncements There have been no material changes in recently issued or adopted accounting standards from those disclose in the Company's 2022 Annual Report on Form 10-K. The Company has reviewed all recently issued accounting pronouncements and does not believe they will have a material impact on our results of operations, financial condition or cash flows. There have been no other material changes to the significant accounting policies previously disclosed in the Company’s 2022 Annual Report on Form 10-K.

Fair Value of Financial Instruments

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

Financial instruments included in the financial statements include cash and cash equivalents, marketable debt and equity securities, accounts receivable, accounts payable, and accrued expenses. Marketable debt securities, equity securities, and cash equivalents are carried at fair value. The fair value of the other financial instruments closely approximates their fair value due to their short-term maturities.

The Company accounts for recurring and non-recurring fair value measurements in accordance with FASB Accounting Standards Codification 820, Fair Value Measurements and Disclosures (ASC 820). ASC 820 defines fair value, establishes a fair value hierarchy for assets and liabilities measured at fair value, and requires expanded disclosure about fair value measurements. The ASC 820 hierarchy ranks the quality of reliable inputs, or assumptions, used in the determination of fair value and requires assets and liabilities carried at fair value to be classified and disclosed in one of the following three categories:

Level 1—Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets or liabilities.

Level 2—Fair value is determined by using inputs other than Level 1 quoted prices that are directly or indirectly observable. Inputs can include quoted prices for similar assets or liabilities in active markets or quoted prices for identical assets or liabilities in markets that are not active. Related inputs can also include those used in valuation or other pricing models, such as interest rates and yield curves that can be corroborated by observable market data.

Level 3—Fair value is determined by inputs that are unobservable and not corroborated by market data. Use of these inputs involves significant and subjective judgments to be made by the reporting entity – e.g., determining an appropriate discount factor for illiquidity associated with a given security.

The Company measures the fair value of financial assets using the highest level of inputs that are reasonably available as of the measurement date. The assets recorded at fair value are classified within the hierarchy as follows for the periods reported (in thousands):


	March 31, 2023 (unaudited)						December 31, 2022
	Total Fair Value		Level 1		Level 2		Total Fair Value		Level 1		Level 2
Money Market Funds	$	56,705	$	56,705	$	—	$	40,967	$	40,967	$	—
Corporate Securities	189,026		—		189,026		200,626		—		200,626
Government Securities	286,896		—		286,896		329,889		—		329,889
	$	532,627	$	56,705	$	475,922	$	571,482	$	40,967	$	530,515

Our policy is to record transfers of assets between Level 1 and Level 2 at their fair values as of the end of each reporting period, consistent with the date of the determination of fair value. During the three months ended March 31, 2023 and 2022, there were no transfers between Level 1 and Level 2.

- 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.

+ References + Details

Net Income (Loss) Per Common Share

3 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Net Income (Loss) Per Common Share

Basic net income (loss) per common share is computed by dividing the net income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding during the period without consideration of common stock equivalents. Diluted net income (loss) per common share is computed by dividing the net income (loss) attributable to common stockholders by the weighted-average number of common stock equivalents outstanding for the period. Potentially dilutive securities consisting of stock issuable pursuant to outstanding options and restricted stock units (RSUs), and stock issuable pursuant to the 2013 Employee Stock Purchase Plan (ESPP) are not included in the per common share calculation in periods when the inclusion of such shares would have an anti-dilutive effect.

Basic and diluted net income (loss) per common share is computed as follows:


	Three Months Ended March 31,
	2023		2022
	(in thousands, except share and per share data)
Numerator:
Net income (loss) attributable to common stockholders	$	(60,763)	$	23,594
Denominator:
Weighted-average common shares outstanding used in computing basic net income (loss)	59,771,674		59,407,829
Effect of dilutive securities	—		1,670,665
Weighted-average common shares outstanding used in computing diluted net income (loss)	59,771,674		61,078,494
Basic net income (loss) per common share	$	(1.02)	$	0.40
Diluted net income (loss) per common share	$	(1.02)	$	0.39

For the three months ended March 31, 2023, all outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per common share as the effect of including such securities would have been anti-dilutive. For the three months ended March 31, 2022, we excluded 2,556,779 shares of stock issuable pursuant to outstanding options and RSUs from the calculation, because the inclusion of such shares would have had an anti-dilutive effect.

Comprehensive Income (Loss)	3 Months Ended
Comprehensive Income (Loss)	Mar. 31, 2023
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Comprehensive Income (Loss)	Comprehensive Income (Loss)Comprehensive income (loss) is comprised of net income (loss) and other comprehensive income (loss). For each of the three-month period ended March 31, 2023 and 2022, the only component of other comprehensive loss is net unrealized gain or loss on marketable debt securities. There were no material reclassifications out of accumulated other comprehensive loss during each of the three-month periods ended March 31, 2023 and 2022.

Marketable Debt and Equity Securities

3 Months Ended

Mar. 31, 2023

Marketable Securities [Abstract]

Marketable Debt and Equity Securities

The Company’s marketable debt securities held as of March 31, 2023 and December 31, 2022 are summarized below:


March 31, 2023	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
(in thousands)
Money Market Funds	$	56,705	$	—	$	—	$	56,705
Corporate Securities	189,658		—		(632)		189,026
Government Securities	289,878		55		(3,037)		286,896
	$	536,241	$	55	$	(3,669)	$	532,627

Reported as
Cash and cash equivalents							$	56,705
Marketable securities							475,922
Total investments							$	532,627


December 31, 2022	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
(in thousands)
Money Market Funds	$	40,967	$	—	$	—	$	40,967
Corporate Securities	201,752		—		(1,126)		200,626
Government Securities	335,705		3		(5,819)		329,889
	$	578,424	$	3	$	(6,945)	$	571,482

Reported as
Cash and cash equivalents							$	40,967
Marketable securities							530,515
Total investments							$	571,482

The maturities of the Company’s marketable debt securities as of March 31, 2023 are as follows:


March 31, 2023	Amortized Cost		Estimated Cost Fair Value
(in thousands)
Mature in one year or less	$	479,536	$	475,922
Mature within two years	—		—
	$	479,536	$	475,922

The unrealized losses on available-for-sale investments and their related fair values as of March 31, 2023 and December 31, 2022 are as follows:


	Less than 12 months				12 months or greater
March 31, 2023	Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	119,220	$	(632)	$	—	$	—
Government Securities	232,044		(3,037)		—		—
	$	351,264	$	(3,669)	$	—	$	—


	Less than 12 months				12 months or greater
December 31, 2022	Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	132,658	$	(1,121)	$	3,826	$	(5)
Government Securities	324,933		(5,819)		—		—
	$	457,591	$	(6,940)	$	3,826	$	(5)

The unrealized losses from the available-for-sale securities are primarily due to changes in the interest rate environment and not changes in the credit quality of the underlying securities in the portfolio.

The Company’s equity securities include securities with a readily determinable fair value. These investments are carried at fair value with changes in fair value recognized each period and reported within other income (expense). For the three months ended March 31, 2023 and March 31, 2022, a loss of $2.9 million and a loss of $3.4 million, respectively, were recorded under other income (expense) related to these securities. Equity securities with a readily determinable fair value, which are categorized as Level 1 in the fair value hierarchy under ASC 820, and their fair values (in thousands) as of March 31, 2023 and December 31, 2022 are as follows:


	Fair Value		Fair Value
	March 31, 2023		December 31, 2022
Astria Common Stock	$	9,282	$	9,529
INmune Common Stock	12,180		11,954
Viridian Common Stock	18,244		20,948
	$	39,706	$	42,431

The Company also has investments in equity securities without a readily determinable fair value. The Company elects the measurement alternative to record these investments at their initial cost and evaluate such investments at each reporting period for evidence of impairment, or observable price changes in orderly transactions for the identical or a similar investment of the same issuer. Equity securities without a readily determinable fair value and their carrying values (in thousands) as of March 31, 2023 and December 31, 2022 are as follows:


	Carrying Value		Carrying Value
	March 31, 2023		December 31, 2022
Astria Preferred Stock	$	—	$	174
Zenas Preferred Stock	54,209		54,209
	$	54,209	$	54,383

The Company received common and preferred stock in Astria in connection with a licensing transaction. The shares of Astria common stock have a readily determinable fair value and the adjustment in the fair value of the Astria common stock from the period ended December 31, 2022 has been recorded as an unrealized loss on equity securities for the three months ended March 31, 2023.

The Company originally recorded its investment in the shares of Astria preferred stock as an equity interest without a readily determinable fair value. In January 2023, the Company exchanged its preferred shares for common stock in Astria. The common stock has a readily determinable fair value and difference in the fair value of the common stock and the carrying value of the preferred stock has been recorded as a gain in equity securities for the three months ended March 31, 2023. The Company recorded a loss in equity securities related to the Astria common stock for the three months ended March 31, 2023.

The Company currently holds 1,885,533 shares of common stock of INmune Bio, Inc. (INmune). The 1,885,533 shares of INmune common stock are classified as equity securities with a readily determinable fair value, and the adjustment in the fair value of the shares of INmune common stock has been recorded as a gain in equity securities for the three months ended March 31, 2023.

The Company currently holds 717,144 shares of common stock of Viridian Therapeutics, Inc. (Viridian). The shares of Viridian common stock are classified as equity securities with a readily determinable fair value, and the adjustment in the fair value of the shares of Viridian common stock was recorded as a loss in equity securities for the three months ended March 31, 2023.

The Company currently holds an equity interest in Zenas BioPharma Limited (Zenas), a private biotechnology company. The Company’s equity interests include preferred stock in Zenas. The Company elected the measurement alternative to carry the Zenas equity at cost minus impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. During the three months ended March 31, 2023, there has not been any impairment or observable price changes related to this investment.

Unrealized loss recognized on equity securities during each of the three-month periods ended March 31, 2023 and 2022, consist of the following:


	Three Months Ended March 31,
	2023		2022
Net loss recognized on equity securities	$	(2,898)	$	(3,429)
Less: net gain recognized on sale of equity securities	—		—
Unrealized loss recognized on equity securities	$	(2,898)	$	(3,429)

Stock-Based Compensation

3 Months Ended

Mar. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Stock Based Compensation

Our Board of Directors (the Board) and the requisite stockholders previously approved the 2010 Equity Incentive Plan (the 2010 Plan). In October 2013, the Board approved the 2013 Equity Incentive Plan (the 2013 Plan), and in November 2013, our stockholders approved the 2013 Plan, which became effective as of December 3, 2013. As of December 2, 2013, we suspended the 2010 Plan, and no additional awards may be granted under the 2010 Plan. Any shares of common stock covered by awards granted under the 2010 Plan that terminate after December 2, 2013 by expiration, forfeiture, cancellation, or other means without the issuance of such shares will be added to the 2013 Plan reserve. The December 2013 Plan will end December 2, 2023 and we will no longer be able to issue shares under the Plan after this date.

As of March 31, 2023, the total number of shares of common stock available for issuance under the 2013 Plan is 17,507,818. Unless otherwise determined by the Board, beginning January 1, 2014, and continuing until the expiration of the 2013 Plan, the total number of shares of common stock available for issuance under the 2013 Plan will automatically increase annually on January 1 of each year by 4% of the total number of issued and outstanding shares of common stock as of December 31 of the immediately preceding year. Pursuant to approval by the Board, the total number of shares of common stock available for issuance under the 2013 Plan was increased by 2,399,908 shares on January 1, 2023. As of March 31, 2023, a total of 16,155,562 options have been granted under the 2013 Plan.

In November 2013, the Board and our stockholders approved the ESPP, which became effective as of December 5, 2013. As of March 31, 2023, the total number of shares of common stock available for issuance under the ESPP is 1,139,369. Unless otherwise determined by the Board, beginning on January 1, 2014, and continuing until the expiration of the ESPP, the total number of shares of common stock available for issuance under the ESPP will automatically increase annually on January 1 by the lesser of (i) 1% of the total number of issued and outstanding shares of common stock as of December 31 of the immediately preceding year, or (ii) 621,814 shares of common stock. Pursuant to approval by the Board, the total number of shares of common stock available for issuance under the ESPP was increased by 599,977 shares on January 1, 2023. As of March 31, 2023, we have issued a total of 635,449 shares of common stock under the ESPP.

During the three months ended March 31, 2023, the Company awarded 862,738 RSUs to certain employees. The standard vesting of these awards is generally in three equal annual installments and is contingent on an employee’s continued service to the Company. The fair value of these awards is determined based on the intrinsic value of the stock on the date of grant and will be recognized as stock-based compensation expense over the requisite service period. As of March 31, 2023, a total of 2,862,555 RSUs have been granted under the 2013 Plan.

Total employee, director and non-employee stock-based compensation expense recognized for the three months ended March 31, 2023 and 2022 are as follows (in thousands):


	Three Months Ended March 31,
	2023		2022
General and administrative	$	4,276	$	3,674
Research and development	8,323		7,131
	$	12,599	$	10,805


	Three Months Ended March 31,
	2023		2022
Stock options	$	6,983	$	6,833
ESPP	322		301
RSUs	5,294		3,671
	$	12,599	$	10,805

The following table summarizes option activity under our stock plans and related information:


	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)
Balance at December 31, 2022	10,082,642	$	29.12	6.30	$	27,141
Options granted	1,620,256	$	31.40
Options forfeited	(51,523)	$	36.18
Options exercised	(34,388)	$	26.82
Balance at March 31, 2023	11,616,987	$	29.42	6.59	$	33,738
Exercisable	7,308,552	$	27.47	5.17	$	33,229

We calculate the intrinsic value as the difference between the exercise price of the options and the closing price of common stock of $27.89 per share as of March 31, 2023.

The weighted-average fair value of options granted during the three-month periods ended March 31, 2023 and March 31, 2022 were $31.40 and $15.85 per share, respectively. There were 1,668,623 options granted during the three-month period ended March 31, 2022. We estimated the fair value of each stock option using the Black-Scholes option-

pricing model based on the date of grant of such stock option with the following weighted average assumptions for the three months ended March 31, 2023 and 2022:


	Options
	Three Months Ended March 31,
	2023		2022
Expected term (years)	6.0		6.4
Expected volatility	50.5	%	53.0	%
Risk-free interest rate	4.26	%	1.78	%
Expected dividend yield	—	%	—	%


	ESPP
	Three Months Ended March 31,
	2023		2022
Expected term (years)	0.5 - 2.0		0.5 - 2.0
Expected volatility	43.2 - 55.7%		55.7	%
Risk-free interest rate	0.13 - 2.82%		0.13% - 0.67%
Expected dividend yield	—	%	—	%

As of March 31, 2023, the unamortized compensation expense related to unvested stock options was $71.9 million. The remaining unamortized compensation expense will be recognized over the next 2.8 years. As of March 31, 2023, the unamortized compensation expense under our ESPP was $0.9 million. The remaining unamortized expense will be recognized over the next 0.7 years.

The following table summarizes the RSU activity for the three-month period ended March 31, 2023:


	Restricted Stock Units	Weighted Average Grant Date Fair Value (Per unit)

Unvested RSUs at December 31, 2022	1,232,551	$	32.41
Granted	862,738	31.22
Vested	(349,499)	32.83
Forfeited	(17,794)	32.88
Unvested RSUs at March 31, 2023	1,727,996	$	31.72

As of March 31, 2023, the unamortized compensation expense related to unvested RSUs was $49.3 million. The remaining unamortized expense will be recognized over the next 2.4 years.

Leases

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Leases

The Company leases office and laboratory space in Monrovia, California under a lease that expires in December 2025 with an option to renew for an additional five years at then market rates. The Company has assessed that it is unlikely to exercise the option to extend the lease term. For the three months ended March 31, 2023, there were no ROU assets obtained in exchange for new operating lease liabilities.

In June 2021, the Company entered into an Agreement of Lease (Lease Agreement) for laboratory and office space in Pasadena, California, which will expire in July 2035. The Lease Agreement provides for two separate phases of lease and occupancy. The first phase commences on August 1, 2022 and provides the Company with an improvement allowance up to $17.0 million. The second phase of the lease agreement will commence no later than September 30, 2026 and includes an additional improvement allowance up to $3.3 million. In August 2022, the Company entered into an

amendment, which the Company would receive an additional $5.0 million in tenant improvement allowance in exchange for an increase in the rental rate of the phase 1 space. The Company placed the new facility into service in February 2023. The Company received delivery of the second phase premises on December 1, 2022. For the three months ended March 31, 2023, there were no ROU assets obtained in exchange for new operating lease liabilities.

The Company leases additional office space in San Diego, California through December 2023. For the three months ended March 31, 2023, there were no ROU assets obtained in exchange for new operating lease liabilities.

The Company’s lease agreements do not contain any residual value guarantees or restrictive covenants.

The following table reconciles the undiscounted cash flows for the operating leases at March 31, 2023 to the operating lease liabilities recorded on the balance sheet (in thousands):


Years ending December 31,
For the remainder of 2023	$	4,789
2024	6,072
2025	7,392
2026	8,589
2027	8,829
2028	9,076
Thereafter	66,436
Total undiscounted lease payments	111,183
Less: Tenant allowance	(5,459)
Less: Imputed interest	(46,481)
Present value of lease payments	$	59,243

Lease liabilities - short-term	$	4,471
Lease liabilities - long-term	54,772
Total lease liabilities	$	59,243

The following table summarizes lease costs and cash payments for the three months ended March 31, 2023 and 2022 (in thousands):


	Three Months Ended March 31,
	2023		2022

Operating lease cost	$	2,181	$	1,562
Variable lease cost	234		99
Total lease costs	$	2,415	$	1,661

Cash paid for amounts included in the measurement of lease liabilities	$	724	$	684

As of March 31, 2023, the weighted-average remaining lease term for operating leases is 11.8 years, and the weighted-average discount rate for operating leases is 8.9%. As of March 31, 2022, the weighted-average remaining lease term for operating leases is 12.3 years, and the weighted-average discount rate for operating leases is 5.8%.

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesFrom time to time, the Company may be subject to various litigation and related matters arising in the ordinary course of business. The Company does not believe it is currently subject to any material matters where there is at least a reasonable possibility that a material loss may be incurred. The Company is obligated to make future payments to third parties under in license agreements, including sublicense fees, royalties, and payments that become due and payable on the achievement of certain development and commercialization milestones. As the amount and timing of sublicense fees and the achievement and timing of these milestones are not probable and estimable, such commitments have not been included on the Company’s balance sheet. The Company has also entered into agreements with third-party vendors that will require us to make future payments upon the delivery of goods and services in future periods.

Collaboration and Licensing Agreements

3 Months Ended

Mar. 31, 2023

Collaboration and Licensing Agreements

Collaboration and Licensing Agreements

The following is a summary description of the material revenue arrangements, including arrangements that generated revenue in the three months ended March 31, 2023 and 2022.

Alexion Pharmaceuticals, Inc.

In January 2013, the Company entered into an Option and License Agreement (the Alexion Agreement) with Alexion Pharmaceuticals, Inc. (Alexion). 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®.

The Company is eligible to receive a contractual milestone for the achievement of certain commercial sales levels of Ultomiris and is also entitled to receive royalties based on a percentage of net sales of Ultomiris sold by Alexion, its affiliates or its sublicensees, which percentage is in the low single digits. Alexion’s royalty obligations continue on a product-by-product and country-by-country basis until the expiration of the last-to-expire valid claim in a licensed patent covering the applicable product in such country.

Under ASC 606, Revenue from Contracts with Customers, the Company recognizes revenue for sales-based royalties upon the subsequent sale of the product. The Company recognized $10.5 million and $6.1 million of royalty revenue under this arrangement for the three months ended March 31, 2023 and 2022, respectively. As of March 31, 2023, there is a receivable of $9.4 million related to royalties due under the arrangement, and there is no deferred revenue related to this agreement.

Astellas Pharma Inc.

Effective March 29, 2019, the Company entered into a Research and License Agreement (the Astellas Agreement) with Astellas Pharma Inc. (Astellas).

Under the Astellas Agreement, Astellas developed ASP2138, a CLDN18.2 x CD3 bispecific antibody, which is currently being developed by Astellas in a Phase 1 study.

At March 31, 2022, the Company recorded a contract asset of $5.0 million related to a future development milestone under the Astellas Agreement, and we received the milestone payment in July 2022.

No revenue was recognized under the arrangement for the three months ended March 31, 2023, and the Company recognized $5.0 million of revenue for the three months ended March 31, 2022. As of March 31, 2023, there is no deferred revenue related to the arrangement.

Astria Therapeutics, Inc.

In connection with a licensing transaction, the Company received preferred and common stock in Astria. In January 2023, the Company exchanged its preferred stock for additional common stock in Astria.

The Company recognized an unrealized loss of $0.4 million related to its equity interest in Astria for the three months ended March 31, 2023. The Company recognized an unrealized gain of $0.8 million related to its equity interest in Astria for the three months ended March 31, 2022. There is no deferred revenue as of March 31, 2023 related to this agreement.

Genentech, Inc., and F. Hoffmann-La Roche Ltd

In February 2019, the Company entered into a collaboration and license agreement (the Genentech Agreement) with Genentech, Inc. and F. Hoffmann-La Roche Ltd (collectively, Genentech) for the development and commercialization of novel IL-15 collaboration products (Collaboration Products), including XmAb306 (also named RG6323), the Company’s IL-15/IL-15Ra candidate.

Pursuant to the Genentech Agreement, XmAb306 is designated as a development program and all costs incurred for developing XmAb306 from March 8, 2019, the effective date of the Genentech Agreement, are being shared with Genentech under the initial cost-sharing percentage of 45%.

The Company did not recognize revenue related to the Genentech Agreement for the three months ended March 31, 2023, or the three months ended March 31, 2022. As of March 31, 2023, there is a $4.2 million payable related to cost-sharing development activities during the first quarter of 2023 for development studies being conducted under the Genentech Agreement. There is no deferred revenue as of March 31, 2023, as obligations to perform research activities have expired.

INmune Bio, Inc.

In connection with a licensing transaction, the Company received common stock in INmune.

For the three months ended March 31, 2023 the Company recorded an unrealized gain of $0.2 million and for the three months ended March 31, 2022, the Company recorded an unrealized loss of $3.4 million related to its investment in INmune.

Janssen Biotech, Inc.

Janssen Agreement

In November 2020, the Company entered into a Collaboration and License Agreement (the Janssen Agreement) with Janssen Biotech, Inc. (Janssen) pursuant to which the Company and Janssen conducted research and development activities to discover novel CD28 bispecific antibodies for the treatment of prostate cancer with Janssen maintaining exclusive worldwide rights to develop and commercialize licensed products identified from the research activities.

Under the Janssen Agreement, the Company conducted research activities and applied its bispecific Fc technology to antibodies targeting prostate cancer provided by Janssen. Upon completion of the research activities Janssen had a candidate selection option to advance an identified candidate for development and commercialization. In November 2021, the Company completed its performance obligations under the research activities and delivered CD28 bispecific antibodies to Janssen, and Janssen exercised its candidate selection option to select a bispecific CD28 antibody for further development. Janssen will assume full responsibility for development and commercialization of the CD28 bispecific antibody candidate.

Second Janssen Agreement

On October 1, 2021, the Company entered into a second Collaboration and License Agreement (the Second Janssen Agreement) with Janssen pursuant to which the Company granted Janssen an exclusive worldwide license to develop, manufacture, and commercialize plamotamab, the Company’s CD20 x CD3 development candidate, and pursuant to which Xencor and Janssen will conduct research and development activities to discover novel CD28 bispecific antibodies. The parties will conduct joint research activities for up to a two-year period to discover XmAb bispecific antibodies against CD28 and undisclosed B cell tumor-targets with Janssen receiving exclusive worldwide rights, subject to certain Xencor opt-in rights, to develop, manufacture and commercialize pharmaceutical products that contain one or more of such discovered antibodies (CD28 Licensed Antibodies). The Second Janssen Agreement became effective on November 5, 2021.

The Company will collaborate with Janssen on further clinical development of plamotamab with Janssen and share development costs with Janssen paying 80% and the Company paying 20% of certain development costs.

The Company is generally responsible for conducting research activities under the Second Janssen Agreement, and Janssen is generally responsible for all development, manufacturing, and commercialization activities for CD28 Licensed Antibodies that are advanced.

In the first quarter of 2023, Janssen selected a B cell target for further development under the Second Janssen Agreement and the Company received a $5.0 million milestone.

There is a receivable of $2.7 million as of March 31, 2023, related to cost-sharing activities for development of plamotamab under the Second Janssen Agreement. The Company recognized $5.2 million and $1.8 million of revenue related to the Second Janssen Agreement for the three months ended March 31, 2023 and 2022, respectively, and there is $30.1 million in deferred revenue as of March 31, 2023 related to the Second Janssen Agreement.

MorphoSys AG

In June 2010, the Company entered into a Collaboration and License Agreement with MorphoSys AG (MorphoSys), which was subsequently amended. Under the agreement, we granted MorphoSys an exclusive worldwide license to the Company’s 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. If certain developmental, regulatory and sales milestones are achieved, the Company is eligible to receive future milestone payments and royalties.

The Company recognized $1.8 million and $2.3 million of royalty revenue during the three months ended March 31, 2023 and 2022, respectively. As of March 31, 2023, there is a receivable of $2.0 million related to estimated royalties due under the arrangement. As of March 31, 2023, there is no deferred revenue related to this agreement.

Novartis Institute for Biomedical Research, Inc.

In June 2016, the Company entered into a Collaboration and License Agreement (the Novartis Agreement) with Novartis Institutes for BioMedical Research, Inc. (Novartis) to develop and commercialize bispecific and other Fc engineered antibody drug candidates using the Company’s proprietary XmAb technologies and drug candidates.

Pursuant to the Novartis Agreement, the Company and Novartis were co-developing vibecotamab worldwide and sharing development costs. In August 2021, Novartis notified the Company it was terminating its rights with respect to the vibecotamab program, which became effective in February 2022. Under the Novartis Agreement, Novartis is responsible for its share of vibecotamab development costs through February 2023.

No revenue was recognized during the three months ended March 31, 2023, or the three months ended March 31, 2022, from the Novartis Agreement. There is no deferred revenue as of March 31, 2023.

Vir Biotechnology, Inc.

In the first quarter of 2020, the Company entered into a Patent License Agreement (the Vir Agreement) with Vir Biotechnology, Inc. (Vir) pursuant to which the Company provided a non-exclusive license to its Xtend technology for up to two targets.

In March 2020, the Company entered into a second Patent License Agreement (the Second Vir Agreement) with Vir pursuant to which the Company provided a non-exclusive license to its Xtend technology to extend the half-life of two novel antibodies that Vir advanced into development to treat patients with COVID-19. VIR incorporated our Xtend technology in developing Sotrovimab which was authorized to treat mild-to-moderate COVID 19 in certain patient populations. Under the terms of the Second Vir Agreement, Vir 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. We began earning royalties from the net sales of Sotrovimab in the second quarter of 2021. As the COVID 19 virus has mutated, our royalties from the sale of Sotrovimab have diminished significantly and future revenues from this license are expected to continue to decline.

The Company recognized $1.5 million and $70.3 million of royalty revenue for the three months ended March 31, 2023 and 2022, respectively. As of March 31, 2023, there is a receivable of $1.5 million related to estimated royalty due under this agreement, and there is no deferred revenue related to this agreement.

Viridian Therapeutics, Inc.

In December 2020 and in December 2021, the Company entered two separate license agreements with Viridian and received shares of Viridian common stock for each license.

The Company reported unrealized loss of $2.7 million and a loss of $0.9 million for the three months ended March 31, 2023 and March 31, 2022 related to the shares of Viridian common stock. The Company did not recognize revenue for the three months ended March 31, 2023 or 2022. There is no deferred revenue as of March 31, 2023 related to this agreement.

Zenas BioPharma Limited

In November 2020, the Company entered into a License Agreement (the Zenas Agreement) with Zenas, pursuant to which the Company received an equity interest in Zenas in exchange for the exclusive, worldwide rights to develop and commercialize drug candidates from the Company.

The equity in Zenas is recorded at the fair value as of the date of the Zenas Agreement and is reviewed each reporting period for impairment or other evidence of change in value.

In November 2021, the Company entered into a second License Agreement (Second Zenas Agreement) with Zenas, pursuant to which the Company received additional equity in Zenas in exchange for the exclusive worldwide rights to develop and commercialize the Company’s obexelimab (XmAb5871) drug candidate. The original equity received for the second license was a warrant to acquire additional shares of Zenas. The warrant was exchanged for additional preferred stock in Zenas in November 2022.

The warrant in Zenas was recorded at its fair value as of the date of the Second Zenas Agreement and is reviewed each reporting period for impairment or other evidence of change in value. The preferred shares received in exchange for the warrant were recorded at their fair value at the date of the exchange and is reviewed each reporting period for impairment or other evidence of change in value.

The Company did not record an impairment or change in the value of the Zenas equity or the warrant in Zenas in the three months ended March 31, 2023 or 2022. The Company did not recognize any revenue related to the Zenas Agreement for the three months ended March 31, 2023 or 2022, and there is no deferred revenue related to this agreement.

Revenue earned

The revenues recorded for the three months ended March 31, 2023 and 2022 were earned principally from the following licensees (in millions):


	Three Months Ended March 31,
	2023		2022
Alexion	$	10.5	$	6.1
Astellas	—		5.0
Janssen	5.2		1.8
MorphoSys	1.8		2.3
Vir	1.5		70.3
Total	$	19.0	$	85.5

The table below summarizes the disaggregation of revenue recorded for the three months ended March 31, 2023 and 2022 (in millions):


	Three Months Ended March 31,
	2023		2022

Research collaboration	$	0.2	$	1.8
Milestone	5.0		5.0
Royalties	13.8		78.7
Total	$	19.0	$	85.5

Remaining Performance Obligations and Deferred Revenue

The Company’s remaining performance obligation as of March 31, 2023 is conducting research activities pursuant to research plans under the Second Janssen Agreement. As of March 31, 2023 and 2022, the Company has deferred revenue of $30.1 million and $35.5 million, respectively. All deferred revenue as of March 31, 2023 is classified as current liabilities as the Company’s obligations to perform services are due on demand when requested by Janssen under the Second Janssen Agreement.

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income taxesThere is no provision for income tax for the three months ended March 31, 2023 or for the three months ended March 31, 2022. As of March 31, 2023, the Company’s deferred income tax assets, consisting primarily of net operating loss and tax credit carryforwards, have been fully offset by a valuation allowance.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI https://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI https://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Summary of Significant Accounting Policies (Polices)	3 Months Ended
Summary of Significant Accounting Policies (Polices)	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim financial statements for Xencor, Inc. (the Company, Xencor, we or us) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of the Company believes are necessary for a fair presentation of the periods presented. The preparation of interim financial statements requires the use of management’s estimates and assumptions that affect reported amounts of assets and liabilities at the date of the interim financial statements and the reported revenues and expenditures during the reported periods. These interim financial results are not necessarily indicative of the results expected for the full fiscal year or for any subsequent interim period. The accompanying unaudited interim financial statements and related notes should be read in conjunction with the audited financial statements and notes thereto included in the Company’s 2022 Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 24, 2023.
Use of Estimates	Use of Estimates The preparation of interim financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, other comprehensive gain (loss) and the related disclosures. On an ongoing basis, management evaluates its estimates, including estimates related to its accrued clinical trial and manufacturing development expenses, stock-based compensation expense, evaluation of intangible assets, investments, leases and other assets for evidence of impairment, fair value measurements, and contingencies. Significant estimates in these interim financial statements include estimates made for royalty revenue, accrued research and development expenses, stock-based compensation expenses, intangible assets, incremental borrowing rate for right-of-use asset and lease liability, estimated standalone selling price of performance obligations, estimated time for completing delivery of performance obligations under certain arrangements, the likelihood of recognizing variable consideration, the carrying value of equity instruments without a readily determinable fair value, and recoverability of deferred tax assets.
Intangible Assets	Intangible Assets The Company maintains definite-lived intangible assets related to certain capitalized costs of acquired licenses and third-party costs incurred in establishing and maintaining its intellectual property rights to its platform technologies and development candidates. These assets are amortized over their useful lives, which are estimated to be the remaining patent life or the contractual term of the license. The straight-line method is used to record amortization expense. The Company assesses its intangible assets for impairment if indicators are present or changes in circumstances suggest that impairment may exist. There was no impairment charge recorded for the three months ended March 31, 2023 and 2022. The Company capitalizes certain in-process intangible assets that are then abandoned when they are no longer pursued or used in current research activities. There was no material abandonment of in-process intangible assets for each of the three months ended March 31, 2023 and March 31, 2022.
Marketable Debt and Equity Securities	Marketable Debt and Equity Securities The Company has an investment policy that includes guidelines on acceptable investment securities, minimum credit quality, maturity parameters, and concentration and diversification. The investment policy limits the maturity of any individual security to a maximum of 36 months. The average maturity of securities in the portfolio as of March 31, 2023 is less than 12 months. The Company invests its excess cash primarily in marketable debt securities issued by investment grade institutions. The Company considers its marketable debt securities to be available-for-sale because it is not more likely than not that the Company will be required to sell the securities before recovery of the amortized cost. These assets are carried at fair value and any impairment losses and recoveries related to the underlying issuer’s credit standing are recognized within other income (expense), while non-credit related impairment losses and recoveries are recognized within accumulated other comprehensive income (loss). There were no impairment losses or recoveries recorded for the three months ended March 31, 2023 and 2022. Accrued interest on marketable debt securities is included in the marketable securities’ carrying value. Each reporting period, the Company reviews its portfolio of marketable debt securities, using both quantitative and qualitative factors, to determine if each security’s fair value has declined below its amortized cost basis. During the three months ended March 31, 2023, the Company recorded an unrealized gain of $3.3 million in its portfolio of marketable debt securities. During the three months ended March 31, 2022, the Company recorded an unrealized loss of $5.6 million. The unrealized losses are due to the changing interest rate environment and are not due to changes in the credit quality of the underlying securities. The unrealized gain is recorded in other comprehensive income (loss) for the three months ended March 31, 2023. The Company receives equity securities in connection with certain licensing transactions with its partners. These investments in equity securities are carried at fair value with changes in fair value recognized each period and reported within other income (expense). For equity securities with a readily determinable fair value, the Company remeasures these equity investments at each reporting period until such time that the investment is sold or disposed. If the Company sells an investment, any realized gain or loss on the sale of the securities will be recognized within other income (expense) in the Statements of Comprehensive Income (Loss) in the period of sale. The Company also has investments in equity securities without a readily determinable fair value, where the Company elects the measurement alternative to record the investment at its initial cost minus impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. There was no impairment charge recorded for the three months ended March 31, 2023 and 2022, in connection with equity securities without a readily determinable fair value.
Recent Accounting Pronouncements	Recent Accounting Pronouncements There have been no material changes in recently issued or adopted accounting standards from those disclose in the Company's 2022 Annual Report on Form 10-K. The Company has reviewed all recently issued accounting pronouncements and does not believe they will have a material impact on our results of operations, financial condition or cash flows. There have been no other material changes to the significant accounting policies previously disclosed in the Company’s 2022 Annual Report on Form 10-K.

Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Assets Recorded at Fair Value

The assets recorded at fair value are classified within the hierarchy as follows for the periods reported (in thousands):


	March 31, 2023 (unaudited)						December 31, 2022
	Total Fair Value		Level 1		Level 2		Total Fair Value		Level 1		Level 2
Money Market Funds	$	56,705	$	56,705	$	—	$	40,967	$	40,967	$	—
Corporate Securities	189,026		—		189,026		200,626		—		200,626
Government Securities	286,896		—		286,896		329,889		—		329,889
	$	532,627	$	56,705	$	475,922	$	571,482	$	40,967	$	530,515

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Net Income (Loss) Per Common Share (Tables)

3 Months Ended

Mar. 31, 2023

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Net Income (Loss) per Common Share

Basic and diluted net income (loss) per common share is computed as follows:


	Three Months Ended March 31,
	2023		2022
	(in thousands, except share and per share data)
Numerator:
Net income (loss) attributable to common stockholders	$	(60,763)	$	23,594
Denominator:
Weighted-average common shares outstanding used in computing basic net income (loss)	59,771,674		59,407,829
Effect of dilutive securities	—		1,670,665
Weighted-average common shares outstanding used in computing diluted net income (loss)	59,771,674		61,078,494
Basic net income (loss) per common share	$	(1.02)	$	0.40
Diluted net income (loss) per common share	$	(1.02)	$	0.39

Marketable Debt and Equity Securities (Tables)

3 Months Ended

Mar. 31, 2023

Marketable Securities [Abstract]

Schedule of Marketable Securities

The Company’s marketable debt securities held as of March 31, 2023 and December 31, 2022 are summarized below:


March 31, 2023	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
(in thousands)
Money Market Funds	$	56,705	$	—	$	—	$	56,705
Corporate Securities	189,658		—		(632)		189,026
Government Securities	289,878		55		(3,037)		286,896
	$	536,241	$	55	$	(3,669)	$	532,627

Reported as
Cash and cash equivalents							$	56,705
Marketable securities							475,922
Total investments							$	532,627


December 31, 2022	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
(in thousands)
Money Market Funds	$	40,967	$	—	$	—	$	40,967
Corporate Securities	201,752		—		(1,126)		200,626
Government Securities	335,705		3		(5,819)		329,889
	$	578,424	$	3	$	(6,945)	$	571,482

Reported as
Cash and cash equivalents							$	40,967
Marketable securities							530,515
Total investments							$	571,482

Schedule of Maturities of Marketable Securities

The maturities of the Company’s marketable debt securities as of March 31, 2023 are as follows:


March 31, 2023	Amortized Cost		Estimated Cost Fair Value
(in thousands)
Mature in one year or less	$	479,536	$	475,922
Mature within two years	—		—
	$	479,536	$	475,922

Schedule of Unrealized Losses on Available-for-Sale Investments

The unrealized losses on available-for-sale investments and their related fair values as of March 31, 2023 and December 31, 2022 are as follows:


	Less than 12 months				12 months or greater
March 31, 2023	Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	119,220	$	(632)	$	—	$	—
Government Securities	232,044		(3,037)		—		—
	$	351,264	$	(3,669)	$	—	$	—


	Less than 12 months				12 months or greater
December 31, 2022	Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	132,658	$	(1,121)	$	3,826	$	(5)
Government Securities	324,933		(5,819)		—		—
	$	457,591	$	(6,940)	$	3,826	$	(5)

Schedule of Equity Securities with Readily Determinable Fair Value

Equity securities with a readily determinable fair value, which are categorized as Level 1 in the fair value hierarchy under ASC 820, and their fair values (in thousands) as of March 31, 2023 and December 31, 2022 are as follows:


	Fair Value		Fair Value
	March 31, 2023		December 31, 2022
Astria Common Stock	$	9,282	$	9,529
INmune Common Stock	12,180		11,954
Viridian Common Stock	18,244		20,948
	$	39,706	$	42,431

Schedule of Equity Securities Without Readily Determinable Fair Value

Equity securities without a readily determinable fair value and their carrying values (in thousands) as of March 31, 2023 and December 31, 2022 are as follows:


	Carrying Value		Carrying Value
	March 31, 2023		December 31, 2022
Astria Preferred Stock	$	—	$	174
Zenas Preferred Stock	54,209		54,209
	$	54,209	$	54,383

Schedule of Net Gains and Losses

Unrealized loss recognized on equity securities during each of the three-month periods ended March 31, 2023 and 2022, consist of the following:


	Three Months Ended March 31,
	2023		2022
Net loss recognized on equity securities	$	(2,898)	$	(3,429)
Less: net gain recognized on sale of equity securities	—		—
Unrealized loss recognized on equity securities	$	(2,898)	$	(3,429)

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2023

Share-Based Payment Arrangement [Abstract]

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

Total employee, director and non-employee stock-based compensation expense recognized for the three months ended March 31, 2023 and 2022 are as follows (in thousands):


	Three Months Ended March 31,
	2023		2022
General and administrative	$	4,276	$	3,674
Research and development	8,323		7,131
	$	12,599	$	10,805


	Three Months Ended March 31,
	2023		2022
Stock options	$	6,983	$	6,833
ESPP	322		301
RSUs	5,294		3,671
	$	12,599	$	10,805

Summary of Stock Option Activity

The following table summarizes option activity under our stock plans and related information:


	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)
Balance at December 31, 2022	10,082,642	$	29.12	6.30	$	27,141
Options granted	1,620,256	$	31.40
Options forfeited	(51,523)	$	36.18
Options exercised	(34,388)	$	26.82
Balance at March 31, 2023	11,616,987	$	29.42	6.59	$	33,738
Exercisable	7,308,552	$	27.47	5.17	$	33,229

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

We estimated the fair value of each stock option using the Black-Scholes option-

pricing model based on the date of grant of such stock option with the following weighted average assumptions for the three months ended March 31, 2023 and 2022:


	Options
	Three Months Ended March 31,
	2023		2022
Expected term (years)	6.0		6.4
Expected volatility	50.5	%	53.0	%
Risk-free interest rate	4.26	%	1.78	%
Expected dividend yield	—	%	—	%

Schedule of Weighted Average Assumptions Used for Estimation of Fair Value of ESPP


	ESPP
	Three Months Ended March 31,
	2023		2022
Expected term (years)	0.5 - 2.0		0.5 - 2.0
Expected volatility	43.2 - 55.7%		55.7	%
Risk-free interest rate	0.13 - 2.82%		0.13% - 0.67%
Expected dividend yield	—	%	—	%

Summary of Restricted Stock Unit Activity

The following table summarizes the RSU activity for the three-month period ended March 31, 2023:


	Restricted Stock Units	Weighted Average Grant Date Fair Value (Per unit)

Unvested RSUs at December 31, 2022	1,232,551	$	32.41
Granted	862,738	31.22
Vested	(349,499)	32.83
Forfeited	(17,794)	32.88
Unvested RSUs at March 31, 2023	1,727,996	$	31.72

Leases (Tables)

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Schedule of Operating Lease Liabilities Maturities

The following table reconciles the undiscounted cash flows for the operating leases at March 31, 2023 to the operating lease liabilities recorded on the balance sheet (in thousands):


Years ending December 31,
For the remainder of 2023	$	4,789
2024	6,072
2025	7,392
2026	8,589
2027	8,829
2028	9,076
Thereafter	66,436
Total undiscounted lease payments	111,183
Less: Tenant allowance	(5,459)
Less: Imputed interest	(46,481)
Present value of lease payments	$	59,243

Lease liabilities - short-term	$	4,471
Lease liabilities - long-term	54,772
Total lease liabilities	$	59,243

Summary of Lease Costs and Cash Disclosures

The following table summarizes lease costs and cash payments for the three months ended March 31, 2023 and 2022 (in thousands):


	Three Months Ended March 31,
	2023		2022

Operating lease cost	$	2,181	$	1,562
Variable lease cost	234		99
Total lease costs	$	2,415	$	1,661

Cash paid for amounts included in the measurement of lease liabilities	$	724	$	684

Collaboration and Licensing Agreements (Tables)

3 Months Ended

Mar. 31, 2023

Collaboration and Licensing Agreements

Schedule of Revenue by Licensees

The revenues recorded for the three months ended March 31, 2023 and 2022 were earned principally from the following licensees (in millions):


	Three Months Ended March 31,
	2023		2022
Alexion	$	10.5	$	6.1
Astellas	—		5.0
Janssen	5.2		1.8
MorphoSys	1.8		2.3
Vir	1.5		70.3
Total	$	19.0	$	85.5

Schedule of Disaggregation of Revenue

The table below summarizes the disaggregation of revenue recorded for the three months ended March 31, 2023 and 2022 (in millions):


	Three Months Ended March 31,
	2023		2022

Research collaboration	$	0.2	$	1.8
Milestone	5.0		5.0
Royalties	13.8		78.7
Total	$	19.0	$	85.5

Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Patents, licenses, and other intangible assets
Impairment of intangible assets	$ 0	$ 0
Abandonment of capitalized intangible assets	321,000	311,000
Impairment loss or recoveries	0	0
Net unrealized gain (loss) on marketable debt securities	3,327,000	(5,611,000)
Impairment on equity securities	0	0
In-process intangible assets
Patents, licenses, and other intangible assets
Abandonment of capitalized intangible assets	$ 0	$ 0

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value of Financial Instruments
Money Market Funds	$ 72,394	$ 53,942
Marketable securities	475,922
Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	532,627	571,482
Corporate Securities
Fair Value of Financial Instruments
Marketable securities	189,026	200,626
Corporate Securities \| Fair Value, Recurring
Fair Value of Financial Instruments
Marketable securities	189,026	200,626
Government Securities
Fair Value of Financial Instruments
Marketable securities	286,896	329,889
Government Securities \| Fair Value, Recurring
Fair Value of Financial Instruments
Marketable securities	286,896	329,889
Money Market Funds
Fair Value of Financial Instruments
Money Market Funds	56,705	40,967
Money Market Funds \| Fair Value, Recurring
Fair Value of Financial Instruments
Money Market Funds	56,705	40,967
Level 1 \| Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	56,705	40,967
Level 1 \| Corporate Securities \| Fair Value, Recurring
Fair Value of Financial Instruments
Marketable securities	0	0
Level 1 \| Government Securities \| Fair Value, Recurring
Fair Value of Financial Instruments
Marketable securities	0	0
Level 1 \| Money Market Funds \| Fair Value, Recurring
Fair Value of Financial Instruments
Money Market Funds	56,705	40,967
Level 2 \| Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	475,922	530,515
Level 2 \| Corporate Securities \| Fair Value, Recurring
Fair Value of Financial Instruments
Marketable securities	189,026	200,626
Level 2 \| Government Securities \| Fair Value, Recurring
Fair Value of Financial Instruments
Marketable securities	286,896	329,889
Level 2 \| Money Market Funds \| Fair Value, Recurring
Fair Value of Financial Instruments
Money Market Funds	$ 0	$ 0

Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net income (loss) attributable to common stockholders	$ (60,763)	$ 23,594
Denominator:
Weighted-average common shares outstanding used in computing basic net income (loss) (in shares)	59,771,674	59,407,829
Effect of dilutive securities (in shares)	0	1,670,665
Weighted-average common shares outstanding used in computing diluted net income (loss) (in shares)	59,771,674	61,078,494
Basic net income (loss) per common share (in dollars per share)	$ (1.02)	$ 0.40
Diluted net income (loss) per common share (in dollars per share)	$ (1.02)	$ 0.39
Securities excluded in calculation of EPS (in shares)		2,556,779

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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+ Details

Marketable Debt and Equity Securities - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities
Money Market Funds	$ 72,394	$ 53,942
Amortized Cost	479,536
Amortized Cost	536,241	578,424
Gross Unrealized Gains	55	3
Gross Unrealized Losses	(3,669)	(6,945)
Marketable securities	475,922
Total investments	532,627	571,482
Money Market Funds
Schedule of Available-for-sale Securities
Money Market Funds	56,705	40,967
Corporate Securities
Schedule of Available-for-sale Securities
Amortized Cost	189,658	201,752
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(632)	(1,126)
Marketable securities	189,026	200,626
Government Securities
Schedule of Available-for-sale Securities
Amortized Cost	289,878	335,705
Gross Unrealized Gains	55	3
Gross Unrealized Losses	(3,037)	(5,819)
Marketable securities	286,896	329,889
Cash and cash equivalents
Schedule of Available-for-sale Securities
Money Market Funds	56,705	40,967
Marketable securities
Schedule of Available-for-sale Securities
Marketable securities	$ 475,922	$ 530,515

Marketable Debt and Equity Securities - Maturities (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Amortized Cost
Mature in one year or less	$ 479,536
Mature within two years	0
Amortized Cost	479,536
Estimated Cost Fair Value
Mature in one year or less	475,922
Mature within two years	0
Estimated Cost Fair Value	$ 475,922

Marketable Debt and Equity Securities - Unrealized Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities
Fair value, less than 12 months	$ 351,264	$ 457,591
Unrealized losses, Less than 12 months	(3,669)	(6,940)
Fair value, 12 months or greater	0	3,826
Unrealized losses, 12 months or greater	0	(5)
Corporate Securities
Schedule of Available-for-sale Securities
Fair value, less than 12 months	119,220	132,658
Unrealized losses, Less than 12 months	(632)	(1,121)
Fair value, 12 months or greater	0	3,826
Unrealized losses, 12 months or greater	0	(5)
Government Securities
Schedule of Available-for-sale Securities
Fair value, less than 12 months	232,044	324,933
Unrealized losses, Less than 12 months	(3,037)	(5,819)
Fair value, 12 months or greater	0	0
Unrealized losses, 12 months or greater	$ 0	$ 0

Marketable Debt and Equity Securities - Equity Securities with Readily Determinable Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Equity Securities
Loss on equity securities	$ 2,898	$ 3,429
Equity Securities with Readily Determinable Fair Value	39,706		$ 42,431
Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	39,706		42,431
Astria/Catabasis \| Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	9,282		9,529
INmune \| Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	12,180		11,954
Viridian \| Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	$ 18,244		$ 20,948

Marketable Debt and Equity Securities - Equity Securities without Readily Determinable Fair Value (Details) - Preferred Stock - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Equity securities without readily determinable fair value
Equity Securities without Readily Determinable Fair Value	$ 54,209	$ 54,383
Astria/Catabasis
Equity securities without readily determinable fair value
Equity Securities without Readily Determinable Fair Value	0	174
Zenas Bio Pharma Limited
Equity securities without readily determinable fair value
Equity Securities without Readily Determinable Fair Value	$ 54,209	$ 54,209

Marketable Debt and Equity Securities - Equity Securities Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Equity Securities
Impairment on equity securities	$ 0	$ 0
License Agreement \| INmune \| Common Stock
Equity Securities
Number of shares owned	1,885,533
Technology License Agreement \| Viridian \| Common Stock
Equity Securities
Number of shares owned	717,144

Marketable Debt and Equity Securities - Net Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Marketable Securities [Abstract]
Net loss recognized on equity securities	$ (2,898)	$ (3,429)
Less: net gain recognized on sale of equity securities	0	0
Unrealized loss recognized on equity securities	$ (2,898)	$ (3,429)

Stock Based Compensation - Narrative (Details) $ / shares in Units, $ in Millions				3 Months Ended		111 Months Ended	112 Months Ended
	Jan. 01, 2023 shares	Jan. 01, 2022 shares	Dec. 02, 2013 shares	Mar. 31, 2023 USD ($) item $ / shares shares	Mar. 31, 2022 $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options granted (in shares)				1,620,256	1,668,623
Closing price of common stock (in dollars per share) \| $ / shares				$ 27.89		$ 27.89	$ 27.89
Weighted average fair value of options granted (in dollars per share) \| $ / shares				$ 31.40	$ 15.85
Unamortized compensation expense \| $				$ 71.9		$ 71.9	$ 71.9
Period to recognize unamortized compensation expense				2 years 9 months 18 days
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance				1,139,369		1,139,369	1,139,369
Annual increase in shares of common stock available for issuance (in shares)	599,977
Awards issued under the plan (in shares)						635,449
Unamortized compensation expense \| $				$ 0.9		$ 0.9	$ 0.9
Period to recognize unamortized compensation expense				8 months 12 days
ESPP \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Annual percentage increase in shares of common stock available for issuance				1.00%
Annual increase in shares of common stock available for issuance (in shares)				621,814
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)				862,738			2,862,555
Annual installment vesting periods \| item				3
Period to recognize unamortized compensation expense				2 years 4 months 24 days
Unamortized compensation expense related to unvested restricted stock units \| $				$ 49.3		$ 49.3	$ 49.3
The 2010 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options granted (in shares)			0
The 2013 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options granted (in shares)						16,155,562
Total number of shares of common stock available for issuance		2,399,908		17,507,818		17,507,818	17,507,818
Annual percentage increase in shares of common stock available for issuance				4.00%
Increase in shares of common stock available for issuance (in shares)		2,399,908

Stock-Based Compensation - Employee Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	$ 12,599	$ 10,805
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	6,983	6,833
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	322	301
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	5,294	3,671
General and administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	4,276	3,674
Research and development
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	$ 8,323	$ 7,131

Stock-Based Compensation - Option Activity (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2022	Dec. 31, 2022
Number of Shares Subject to Outstanding Options
Balance at the beginning of the period (in shares)	10,082,642
Options granted (in shares)	1,620,256	1,668,623
Options forfeited (in shares)	(51,523)
Options exercised (in shares)	(34,388)
Balance at the end of the period (in shares)	11,616,987
Exercisable options (in shares)	7,308,552
Weighted Average Exercise Price (Per Share)
Balance at the beginning of the period (in dollars per share)	$ 29.12
Options granted (in dollars per share)	31.40
Options forfeited (in dollars per share)	36.18
Options exercised (in dollars per share)	26.82
Balance at the end of the period (in dollars per share)	29.42
Exercisable (in dollars per share)	$ 27.47
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-average remaining contractual term, balance outstanding	6 years 7 months 2 days		6 years 3 months 18 days
Weighted-average remaining contractual term, exercisable	5 years 2 months 1 day
Aggregate intrinsic value, balance outstanding	$ 33,738			$ 27,141
Aggregate intrinsic value, exercisable	$ 33,229

Stock-Based Compensation - FV of Employee Stock Options (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Weighted average assumptions for estimated fair value of employee stock options
Expected dividend yield	0.00%	0.00%
Stock options
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	6 years	6 years 4 months 24 days
Expected volatility (as a percent)	50.50%	53.00%
Risk-free interest rate (as a percent)	4.26%	1.78%
ESPP
Weighted average assumptions for estimated fair value of employee stock options
Expected volatility, low end of range (as a percent)	43.20%
Expected volatility, high end of range (as a percent)	55.70%
Expected volatility (as a percent)		55.70%
Risk-free interest rate, low end of range (as a percent)	0.13%	0.13%
Risk-free interest rate, high end of range (as a percent)	2.82%	0.67%
ESPP \| Minimum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	6 months	6 months
ESPP \| Maximum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	2 years	2 years

Stock Based Compensation - Restricted Stock Units (Details) - RSUs - $ / shares	3 Months Ended	112 Months Ended
	Mar. 31, 2023	Mar. 31, 2023
Restricted Stock Units
Beginning balance (in shares)	1,232,551
Granted (in shares)	862,738	2,862,555
Vested (in shares)	(349,499)
Forfeited (in shares)	(17,794)
Ending balance (in shares)	1,727,996	1,727,996
Weighted Average Grant Date Fair Value (Per unit)
Weighted average grant date fair value, beginning balance (in dollars per share)	$ 32.41
Weighted average grant date fair value, granted (in dollars per share)	31.22
Weighted average grant date fair value, vested (in dollars per share)	32.83
Weighted average grant date fair value, forfeited (in dollars per share)	32.88
Weighted average grant date fair value, ending balance (in dollars per share)	$ 31.72	$ 31.72

Leases - Agreements (Details) $ in Millions	1 Months Ended
Leases - Agreements (Details) $ in Millions	Jun. 30, 2021 item	Sep. 30, 2026 USD ($)	Mar. 31, 2023	Aug. 31, 2022 USD ($)	Aug. 01, 2022 USD ($)
Monrovia, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Renewal term			5 years
Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Phases of lease term \| item	2
Improvement allowance				$ 5.0	$ 17.0
Forecast [Member] \| Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Improvement allowance		$ 3.3

Leases - Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Leases [Abstract]
For the remainder of 2023	$ 4,789
2024	6,072
2025	7,392
2026	8,589
2027	8,829
2028	9,076
Thereafter	66,436
Total undiscounted lease payments	111,183
Less: Tenant allowance	(5,459)
Less: Imputed interest	(46,481)
Present value of lease payments	59,243
Lease liabilities - short-term	4,471	$ 4,708
Lease liabilities - long-term	$ 54,772	$ 54,926

Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
Leases - Lease Costs (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Operating lease cost	$ 2,181	$ 1,562
Variable lease cost	234	99
Total lease costs	2,415	1,661
Cash paid for amounts included in the measurement of lease liabilities	$ 724	$ 684
Remaining lease term	11 years 9 months 18 days	12 years 3 months 18 days
Discount rate	8.90%	5.80%

Collaboration and Licensing Agreements - Narrative (Details) $ in Thousands			1 Months Ended		3 Months Ended			13 Months Ended
	Oct. 01, 2021	Mar. 08, 2019	Mar. 31, 2020 item	Jan. 31, 2013 Program	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2020 item	Dec. 31, 2021 agreement	Dec. 31, 2022 USD ($)
Collaboration research and licensing agreements
Receivable					$ 19,861				$ 28,997
Deferred revenue					30,100	$ 35,500
Unrealized loss recognized on equity securities					(2,898)	(3,429)
Number of technology license agreements \| agreement								2
Impairment on equity securities					0	0
Option and license agreement \| Alexion
Collaboration research and licensing agreements
Number of different target programs \| Program				1
Receivable					9,400
Deferred revenue					0
Research and License Agreement \| Astellas
Collaboration research and licensing agreements
Revenue recognized					0	5,000
Deferred revenue					0
Research and License Agreement \| Astellas \| Milestone
Collaboration research and licensing agreements
Contract asset						5,000
Collaboration and License Agreement \| Genentech
Collaboration research and licensing agreements
Revenue recognized					0	0
Initial cost-sharing percentage		45.00%
Collaboration and License Agreement \| Genentech \| Research service
Collaboration research and licensing agreements
Deferred revenue					0
Collaboration and License Agreement \| Genentech \| XmAb24306
Collaboration research and licensing agreements
Cost sharing receivable (payable)					4,200
Collaboration and License Agreement \| MorphoSys
Collaboration research and licensing agreements
Deferred revenue					0
Collaboration and License Agreement \| MorphoSys \| Royalties
Collaboration research and licensing agreements
Revenue recognized					1,800	2,300
Receivable					2,000
Collaboration and License Agreement \| Novartis
Collaboration research and licensing agreements
Revenue recognized					0	0
Deferred revenue					0
License Agreement \| INmune
Collaboration research and licensing agreements
Unrealized loss recognized on equity securities					200	(3,400)
License Agreement \| Zenas Bio Pharma Limited
Collaboration research and licensing agreements
Revenue recognized					0	0
Deferred revenue					0
Impairment on equity securities					0	0
Second Collaboration And License Agreement \| Janssen Biotech, Inc
Collaboration research and licensing agreements
Revenue recognized					5,200	1,800
Receivable					2,700
Deferred revenue					30,100
Research license term	2 years
Share development percentage	80.00%
Percentage of responsibility for development costs	20.00%
Proceeds from milestone payments					5,000
Patent License Agreement \| Vir
Collaboration research and licensing agreements
Number of different target programs \| item			2				2
Receivable					1,500
Deferred revenue					0
Patent License Agreement \| Vir \| Royalties
Collaboration research and licensing agreements
Revenue recognized					1,500	70,300
Technology License Agreement \| Astria/Catabasis
Collaboration research and licensing agreements
Deferred revenue					0
Unrealized loss recognized on equity securities					(400)	800
Technology License Agreement \| Viridian
Collaboration research and licensing agreements
Revenue recognized					0	0
Deferred revenue					0
Unrealized loss recognized on equity securities					$ (2,700)	$ (900)

Collaboration and Licensing Agreements - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Collaboration research and licensing agreements
Revenue recorded	$ 18,962	$ 85,495
Research collaboration
Collaboration research and licensing agreements
Revenue recorded	200	1,800
Milestone
Collaboration research and licensing agreements
Revenue recorded	5,000	5,000
Royalties
Collaboration research and licensing agreements
Revenue recorded	13,800	78,700
Alexion
Collaboration research and licensing agreements
Revenue recorded	10,500	6,100
Astellas
Collaboration research and licensing agreements
Revenue recorded	0	5,000
Janssen
Collaboration research and licensing agreements
Revenue recorded	5,200	1,800
MorphoSys
Collaboration research and licensing agreements
Revenue recorded	1,800	2,300
Vir
Collaboration research and licensing agreements
Revenue recorded	$ 1,500	$ 70,300

Income Taxes (Details) - USD ($)	3 Months Ended
Income Taxes (Details) - USD ($)	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0

- Definition

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

+ References + Details