0001628280-23-005127 | 10-K | XBRL Viewer

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Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2022	Feb. 15, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36182
Entity Registrant Name	Xencor, Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-1622502
Entity Address, Address Line One	111 West Lemon Avenue
Entity Address, City or Town	Monrovia
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91016
City Area Code	626
Local Phone Number	305-5900
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	XNCR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,624,180,194
Entity Common Stock, Shares Outstanding		60,030,076
Documents Incorporated by Reference	Portions of the registrant’s proxy statement to be filed with the Securities and Exchange Commission pursuant to Regulation 14A in connection with the registrant’s 2021 Annual Meeting of Stockholders, which will be filed subsequent to the date hereof, are incorporated by reference into Part III of this Form 10-K. Such proxy statement will be filed with the Securities and Exchange Commission not later than 120 days following the end of the registrant’s fiscal year ended December 31, 2022.
Entity Central Index Key	0001326732
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Audit Information [Abstract]
Auditor Firm ID	49
Auditor Name	RSM US LLP
Auditor Location	Los Angeles, California

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 53,942	$ 143,480
Marketable debt securities	526,689	153,767
Marketable equity securities	42,431	36,860
Accounts receivable	28,997	66,384
Prepaid expenses and other current assets	23,283	23,877
Total current assets	675,342	424,368
Property and equipment, net	59,183	28,240
Patents, licenses, and other intangible assets, net	18,500	16,493
Marketable debt securities - long term	3,826	300,465
Equity securities	54,383	31,262
Notes receivable - long term	0	5,000
Right of use asset	34,419	31,730
Other assets	613	653
Total assets	846,266	838,211
Current liabilities
Accounts payable	10,088	14,001
Accrued expenses	18,728	19,443
Lease liabilities	4,708	0
Deferred revenue	30,320	37,294
Total current liabilities	63,844	70,738
Lease liabilities, net of current portion	54,926	33,969
Total liabilities	118,770	104,707
Commitments and contingencies (see note 9)
Stockholders’ equity
Preferred stock, $0.01 par value: 10,000,000 authorized shares; -0- issued and outstanding shares at December 31, 2022 and 2021	0	0
Common stock, $0.01 par value: 200,000,000 authorized shares; 59,997,713 issued and outstanding shares at December 31, 2022 and 59,355,558 issued and outstanding at December 31, 2021	601	595
Additional paid-in capital	1,072,132	1,017,523
Accumulated other comprehensive income	(6,952)	(1,510)
Accumulated deficit	(338,285)	(283,104)
Total stockholders’ equity	727,496	733,504
Total liabilities and stockholders’ equity	$ 846,266	$ 838,211

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
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)	59,997,713	59,355,558
Common stock, shares outstanding (in shares)	59,997,713	59,355,558

Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue
Collaborations, licenses, milestones, and royalties	$ 164,579	$ 275,111	$ 122,694
Operating expenses
Research and development	199,563	192,507	169,802
General and administrative	47,489	38,837	29,689
Total operating expenses	247,052	231,344	199,491
Income (loss) from operations	(82,473)	43,767	(76,797)
Other income (expense)
Interest income, net	4,817	849	7,264
Other income (expense), net	(286)	(1,274)	95
Gain on equity securities, net	23,434	39,289	105
Total other income, net	27,965	38,864	7,464
Income (loss) before income tax	(54,508)	82,631	(69,333)
Income tax expense	673	0	0
Net income (loss)	(55,181)	82,631	(69,333)
Other comprehensive income (loss)
Net unrealized loss on marketable securities available-for-sale	(5,442)	(1,584)	(1,087)
Comprehensive income (loss)	$ (60,623)	$ 81,047	$ (70,420)
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.93)	$ 1.42	$ (1.21)
Diluted (in dollars per share)	$ (0.93)	$ 1.37	$ (1.21)
Weighted average shares used to compute net income (loss) per share attributable to common stockholders:
Basic (in shares)	59,652,461	58,379,641	57,212,737
Diluted (in shares)	59,652,461	60,495,455	57,212,737

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, 2019		56,902,301
Beginning balance at Dec. 31, 2019	$ 593,201	$ 569	$ 887,873	$ 1,161	$ (296,402)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock awards (in shares)		858,470
Issuance of common stock upon exercise of stock awards	16,617	$ 9	16,608
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		50,318
Issuance of common stock under the Employee Stock Purchase Plan	1,427	$ 1	1,426
Issuance of restricted stock units (in shares)		62,355
Issuance of restricted stock units	0	$ 1	(1)
Comprehensive income (loss)	(70,420)			(1,087)	(69,333)
Stock-based compensation	31,619		31,619
Ending balance (in shares) at Dec. 31, 2020		57,873,444
Ending balance at Dec. 31, 2020	572,444	$ 580	937,525	74	(365,735)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Sale of common stock (in shares)		748,062
Sale of common stock	28,920	$ 7	28,913
Issuance of common stock upon exercise of stock awards (in shares)		520,240
Issuance of common stock upon exercise of stock awards	12,281	$ 5	12,276
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		62,257
Issuance of common stock under the Employee Stock Purchase Plan	1,837	$ 1	1,836
Issuance of restricted stock units (in shares)		151,555
Issuance of restricted stock units	0	$ 2	(2)
Comprehensive income (loss)	81,047			(1,584)	82,631
Stock-based compensation	36,975		36,975
Ending balance (in shares) at Dec. 31, 2021		59,355,558
Ending 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)		195,485
Issuance of common stock upon exercise of stock awards	3,610	$ 2	3,608
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		105,597
Issuance of common stock under the Employee Stock Purchase Plan	2,092	$ 1	2,091
Issuance of restricted stock units (in shares)		341,073
Issuance of restricted stock units	0	$ 3	(3)
Comprehensive income (loss)	(60,623)			(5,442)	(55,181)
Stock-based compensation	48,913		48,913
Ending balance (in shares) at Dec. 31, 2022		59,997,713
Ending balance at Dec. 31, 2022	$ 727,496	$ 601	$ 1,072,132	$ (6,952)	$ (338,285)

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income (loss)	$ (55,181)	$ 82,631	$ (69,333)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	8,799	7,491	5,794
Amortization of premium (accretion of discount) on marketable securities	127	3,160	(272)
Stock-based compensation	48,913	36,975	31,619
Abandonment of capitalized intangible assets	1,510	934	535
Loss on disposal of assets	145	462	4
Gain on sale of marketable securities available-for-sale	0	0	(153)
Equity received in connection with license agreement	(5,397)	(22,379)	(26,660)
Equity received in connection with sale of financial assets	0	(3,300)	0
Cash redemption of equity received in connection with license agreement	0	0	5,390
Change in fair value of equity securities	(23,434)	(20,988)	(105)
Equity securities impairment	138	762	0
Changes in operating assets and liabilities:
Accounts receivable and contract assets	37,387	(54,941)	10,131
Interest receivable from marketable debt securities	(530)	655	1,190
Prepaid expenses and other assets	634	(13,151)	(4,170)
Income tax	0	0	895
Contract asset and deposits	0	12,059	(12,401)
Accounts payable	(3,913)	5,047	(1,235)
Accrued expenses	(715)	1,840	8,608
Lease liabilities and ROU assets	22,976	1,211	(325)
Deferred revenue	(6,974)	(55,321)	45,484
Net cash provided by (used in) operating activities	24,485	(16,853)	(5,004)
Cash flows from investing activities
Proceeds from sale and maturities of marketable securities available-for-sale	306,607	485,152	757,617
Proceeds from sale of property and equipment	0	19	1
Purchase of marketable securities	(387,928)	(509,597)	(643,658)
Purchase of intangible assets	(4,910)	(2,682)	(3,229)
Purchase of property and equipment	(38,494)	(13,299)	(10,539)
Conversion (purchase) of convertible note	5,000	(5,000)	0
Exercise of stock options	0	(842)	0
Net cash provided by (used in) investing activities	(119,725)	(46,249)	100,192
Cash flows from financing activities
Proceeds from issuance of common stock upon exercise of stock awards	3,610	12,281	16,617
Proceeds from issuance of common stock from Employee Stock Purchase Plan	2,092	1,837	1,427
Proceeds from issuance of common stock	0	28,920	0
Net cash provided by financing activities	5,702	43,038	18,044
Net (decrease) increase in cash and cash equivalents	(89,538)	(20,064)	113,232
Cash and cash equivalents, beginning of year	143,480	163,544	50,312
Cash and cash equivalents, end of year	53,942	143,480	163,544
Cash paid for:
Interest	13	14	15
Taxes	700	0	0
Supplemental Schedule of Noncash Activities
Net unrealized gain (loss) on marketable securities available-for-sale	(5,442)	(1,584)	(1,087)
Addition of right-of-use asset	$ 6,155	$ 24,047	$ 3,127

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Description of Business

Xencor, Inc. (we, us, our, or the Company) was incorporated in California in 1997 and reincorporated in Delaware in September 2004. We are a clinical-stage biopharmaceutical company focused on discovering and developing engineered monoclonal bispecific antibody and cytokine therapeutics to treat patients with cancer and autoimmune diseases who have unmet medical needs. We create our product candidates using our proprietary XmAb technology platforms, which focus on the portion of an antibody that interacts with multiple segments of the immune system, referred to as the Fc domain, which is constant and interchangeable among antibodies. Our engineered Fc domains, the XmAb technology, can increase antibody immune inhibition, improve cytotoxicity, extend half-life and most recently are used to create bispecific antibodies and cytokines.

Our operations are based in Monrovia, California and San Diego, California.

Basis of Presentation

The Company’s financial statements as of December 31, 2022, 2021, and 2020 and for the years then ended have been prepared in accordance with accounting principles generally accepted in the United States (U.S.).

Use of Estimates

The preparation of 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 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.

Recent Accounting Pronouncements

Pronouncements Not yet Effective

In June 2022, the Financial Accounting Standards Board (FASB) issued ASU No. 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions, which is effective for fiscal years beginning on and after December 15, 2023, and interim periods within those fiscal years. The standard clarifies that a contractual restriction on the sale of an equity security is not considered part of the unit of account of the equity security and is not considered in measuring fair value. The Company does not anticipate that the standard will have a significant impact on its financial statements.

Revenue Recognition

We have, to date, earned revenue from research and development collaborations, which may include research and development services, licenses of our internally developed technologies, licenses of our internally developed drug candidates, or combinations of these.

The terms of our license, research and development, and collaboration agreements generally include non-refundable upfront payments, research funding, co-development payments and reimbursements, license fees, and milestone and other contingent payments to us for the achievement of defined collaboration objectives and certain clinical, regulatory and sales-based events, as well as royalties on sales of any commercialized products.

The terms of our licensing agreements include non-refundable upfront fees, annual licensing fees, and contractual payment obligations for the achievement of pre-defined preclinical, clinical, regulatory and sales-based events by our partners. The licensing agreements also include royalties on sales of any commercialized products by our partners.

We recognize revenue through the five-step process in accordance with Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers, when control of the promised goods or services is transferred to our customers in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services.

Deferred Revenue

Deferred revenue arises from payments received in advance of the culmination of the earnings process. We have classified deferred revenue for which we stand ready to perform within the next 12 months as a current liability. We recognize deferred revenue as revenue in future periods when the applicable revenue recognition criteria have been met. The total amounts reported as deferred revenue were $30.3 million and $37.3 million at December 31, 2022 and 2021, respectively.

Accounts Receivable

Accounts receivable primarily consists of royalty and milestone revenues receivable from our license and collaboration agreements, as well as receivables arising from cost-sharing development activities. We did not record an allowance for doubtful accounts at December 31, 2022 or 2021, as we expect to collect all receivables within the terms, which are generally between 30 and 60 days.

Research and Development Expenses

Research and development expenses include costs we incur for our own and for our collaborators’ research and development activities. Research and development costs are expensed as incurred. These costs consist primarily of salaries and benefits, including associated stock-based compensation, laboratory supplies, facility costs, and applicable overhead expenses of personnel directly involved in the research and development of new technology and products, as well as fees paid to other entities that conduct certain research and development activities on our behalf. We estimate preclinical study and clinical trial expenses based on the services performed pursuant to the contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on our behalf based on the actual time and expenses they incurred. Further, we accrue expenses related to clinical trials based on the level of patient enrollment and activity according to the related agreement. We monitor patient enrollment levels and related activity to the extent reasonably possible and adjust estimates accordingly.

We capitalize acquired research and development technology licenses and third-party contract rights where such assets have an alternative use and amortize the costs over the shorter of the license term or the expected useful life. We review the license arrangements and the amortization period on a regular basis and adjust the carrying value or the amortization period of the licensed rights if there is evidence of a change in the carrying value or useful life of the asset.

Cash and Cash Equivalents

We consider cash equivalents to be only those investments which are highly liquid, readily convertible to cash and which mature within three months from the date of purchase.

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 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 and does not intend to sell these securities, and it is not more likely than not the Company will be required to sell the securities before recovery of the amortized cost basis. 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 years ended in December 31, 2022 and 2021, respectively. Accrued interest on

marketable debt securities is included in marketable securities’ carrying value. Accrued interest was $1.3 million and $0.8 million at December 31, 2022 and 2021, respectively. 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 years ended December 31, 2022 and 2021, the Company recorded an unrealized loss of $5.4 million and $1.6 million, respectively, in its portfolio of marketable debt securities. The unrealized losses were due to the changing interest rate environment and are not due to changes in the credit quality of the underlying securities. The unrealized losses were recorded in other comprehensive income (loss) for the years then ended.

The Company receives equity securities in connection with certain licensing transactions with its partners. These investments in an equity security 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 gains or losses on the sale of the securities will be recognized within other income (expense) in the Statement 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 at their 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. During the years ended December 31, 2022 and 2021, the Company recorded an impairment charge of $0.1 million and $0.8 million, respectively, in connection with equity securities without a readily determinable fair value.

During the years ended December 31, 2022 and 2021, the Company recorded a net gain of $23.4 million and $39.3 million, respectively, in connection with its equity investments.

Concentrations of Risk

Cash, cash equivalents, and marketable debt securities are financial instruments that potentially subject the Company to concentrations of risk. We invest our cash in corporate debt securities and U.S. sponsored agencies with strong credit ratings. We have established guidelines relative to diversification and maturities that are designed to help ensure safety and liquidity. These guidelines are periodically reviewed to take advantage of trends in yields and interest rates.

Cash and cash equivalents are maintained at financial institutions, and at times, balances may exceed federally insured limits. We have never experienced any losses related to these balances. Amounts on deposit in excess of federally insured limits at December 31, 2022 and 2021 approximated $53.6 million and $143.2 million, respectively.

We have payables with two service providers that represent 45% of our total payables and with four service providers that represented 64% of our total payables at December 31, 2022 and 2021, respectively. We rely on five critical suppliers for the manufacture of our drug product for use in our clinical trials. While we believe that there are alternative vendors available, a change in manufacturing vendors could cause a delay in the availability of drug product and result in a delay of conducting and completing our clinical trials. No other vendor accounted for more than 10% of total payables at December 31, 2022 or 2021.

We have receivables with four service providers that represent 91% of our total receivables and with two service providers that represent 84% of our total receivables at December 31, 2022 and 2021, respectively. The receivables are related to royalty revenues from our licensing and collaboration agreements. No other customer accounted for more than 10% of total receivables at December 31, 2022 or 2021.

Fair Value of Financial Instruments

Our financial instruments primarily consist of cash and cash equivalents, marketable debt securities, accounts receivable, accounts payable, and accrued expenses. Marketable debt securities and cash equivalents are carried at fair value. The fair value of a financial instrument is the amount that would be received in an asset sale or paid to transfer a liability in an orderly transaction between unaffiliated market participants. The fair value of the other financial instruments closely approximate their fair value due to their short maturities.

The Company accounts for recurring and non-recurring fair value measurements in accordance with FASB ASC 820, Fair Value Measurements and Disclosures. 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):


	December 31, 2022
	Total Fair Value		Level 1		Level 2		Level 3

Money Market Funds in Cash and Cash Equivalents	$	40,967	$	40,967	$	—	$	—
Corporate Securities	200,626		—		200,626		—
Government Securities	329,889		—		329,889		—

	$	571,482	$	40,967	$	530,515	$	—


	December 31, 2021
	Total Fair Value		Level 1		Level 2		Level 3

Money Market Funds in Cash and Cash Equivalents	$	123,892	$	123,892	$	—	$	—
Corporate Securities	144,418		—		144,418		—
Government Securities	309,814		—		309,814		—

	$	578,124	$	123,892	$	454,232	$	—

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 years ended December 31, 2022 and 2021, there were no transfers between Level 1 and Level 2.

Property and Equipment

Property and equipment are recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets. Expenditures for repairs and maintenance are charged to expense as incurred, while renewals and improvements are capitalized. Useful lives by asset category are as follows:


Computers, software and equipment			3 - 5 years
Furniture and fixtures			5 - 7 years
Leasehold improvements			5 - 7 years or remaining
			lease term, whichever is less

Patents, Licenses, and Other Intangible Assets

The cost of acquiring licenses is capitalized and amortized on the straight-line basis over the shorter of the term of the license or its estimated economic life, ranging from 1 to 18 years. Third-party costs incurred for acquiring patents are capitalized. Capitalized costs are accumulated until the earlier of the period that a patent is issued, or we abandon the patent claims. Cumulative capitalized patent costs are amortized on a straight-line basis from the date of issuance over the shorter of the patent term or the estimated useful economic life of the patent, ranging from 3 to 27 years. Our senior management, with advice from outside patent counsel, assesses three primary criteria to determine if a patent will be capitalized initially: i) technical feasibility, ii) magnitude and scope of new technical function covered by the patent compared to the company’s existing technology and patent portfolio, particularly assessing the value added to our product candidates or licensing business, and iii) legal issues, primarily assessment of patentability and prosecution cost. We review our intellectual property on a regular basis to determine if there are changes in the estimated useful life of issued patents and if any capitalized costs for unissued patents should be abandoned. Capitalized patent costs related to abandoned patent filings are charged off in the period of the decision to abandon. During 2022, 2021, and 2020, we abandoned previously capitalized patent and licensing related charges of $1.5 million, $0.9 million, and $0.5 million, respectively.

The carrying amount and accumulated amortization of patents, licenses, and other intangibles is as follows (in thousands):


	December 31,
	2022		2021
Patents, definite life	$	14,535	$	13,231
Patents, pending issuance	9,328		8,821
Licenses and other amortizable intangible assets	3,908		2,474
Nonamortizable intangible assets (trademarks)	399		399
Total gross carrying amount	28,170		24,925
Accumulated amortization—patents	(7,781)		(6,800)
Accumulated amortization—licenses and other	(1,889)		(1,632)
Total intangible assets, net	$	18,500	$	16,493

Amortization expense for patents, licenses, and other intangible assets was $1.4 million, $1.2 million, and $1.1 million for the years ended December 31, 2022, 2021, and 2020, respectively.

Future amortization expense for patent, licenses, and other intangible assets recorded as of December 31, 2022, and for which amortization has commenced, is as follows:


	Year ended December 31,
	(in thousands)
2023	$	1,165
2024	1,123
2025	1,110
2026	1,097
2027	1,096
Thereafter	3,181
Total	$	8,772

The above amortization expense forecast is an estimate. Actual amounts of amortization expense may differ from estimated amounts due to additional intangible asset acquisitions, impairment of intangible assets, accelerated amortization of intangible assets, and other events. As of December 31, 2022, the Company has $9.3 million of intangible assets which are in-process and have not been placed in service, and accordingly amortization on these assets has not commenced.

Long-Lived Assets

Management reviews long-lived assets which include fixed assets and amortizable intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets.

We did not recognize a loss from impairment for the years ended December 31, 2022, 2021, or 2020.

Income Taxes

We account for income taxes in accordance with accounting guidance which requires an asset and liability approach to financial accounting and reporting for income taxes. Deferred income tax assets and liabilities are computed annually for differences between the financial statement and tax bases of assets and liabilities that will result in taxable or deductible amounts in the future based on enacted tax laws and rates applicable to the periods in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. Income tax expense is the tax payable or refundable for the period plus or minus the change during the period in deferred tax assets and liabilities.

We assess our income tax positions and record tax benefits for all years subject to examination based upon our evaluation of the facts, circumstances, and information available at the reporting date. For those tax positions where there is greater than 50% likelihood that a tax benefit will be sustained, we have recorded the largest amount of tax benefit that may potentially be realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. For those income tax positions where there is a 50% or less likelihood that a tax benefit will be sustained, no tax benefit has been recognized in the financial statements. We did not have any material uncertain tax positions at December 31, 2022 or 2021.

Our policy is to recognize interest and penalties on taxes, if any, as a component of income tax expense.

The Tax Cuts and Jobs Act of 2017 (TCJA) enacted on December 22, 2017 included several key provisions impacting the accounting for and reporting of income taxes. The most significant provisions reduced the U.S. corporate statutory tax rate from 35% to 21%, eliminated the corporate Alternative Minimum Tax (AMT) system, and made changes to the carryforward of net operating losses beginning on January 1, 2018. The TCJA changed the income tax treatment of research and development expenses requiring such costs to be capitalized and amortized over several years beginning effective January 1, 2022. The tax reform also provided for a refund of unused AMT carryforwards for years beginning after December 31, 2017. We received an income tax refund during the year ended December 31, 2020 of $0.8 million each year related to our federal AMT carryforwards.

Stock-Based Compensation

We recognize compensation expense using a fair-value-based method for costs related to all share-based payments, including stock options, restricted stock units (RSUs), and shares issued under our Employee Stock Purchase Plan (ESPP). Stock-based compensation cost related to employees and directors is measured at the grant date, based on the fair-value-based measurement of the award using the Black-Scholes method, and is recognized as expense over the requisite service period on a straight-line basis. We account for forfeitures when they occur. We recorded stock-based compensation and expense for stock-based awards to employees, directors, and consultants of approximately $48.9 million, $37.0 million, and $31.6 million for the years ended December 31, 2022, 2021, and 2020, respectively.

Net Income (Loss) Per 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:

Basic net income (loss) per common share is computed by dividing the net income or loss by the weighted-average number of common shares outstanding during the period. Potentially dilutive securities were included in the diluted net income per common share calculation for 2021.

In 2022 and 2020, we excluded all options and awards from the calculations because we reported net losses in the period, and the inclusion of such shares would have had an antidilutive effect.


	Year Ended December 31,
	2022		2021		2020
	(in thousands, except share and per share data)
Basic
Numerator:
Net income (loss) attributable to common stockholders for basic net income (loss) per share	$	(55,181)	$	82,631	$	(69,333)
Denominator:
Weighted-average common shares outstanding	59,652,461		58,379,641		57,212,737
Basic net income (loss) per common share	$	(0.93)	$	1.42	$	(1.21)

Diluted
Numerator:
Net income (loss) attributable to common stockholders for diluted net income (loss) per share	$	(55,181)	$	82,631	$	(69,333)
Denominator:
Weighted average number of common shares outstanding used in computing basic net income (loss) per common share	59,652,461		58,379,641		57,212,737
Dilutive effect of employee stock options, RSUs, and ESPP	—		2,115,814		—
Weighted-average number of common shares outstanding used in computing diluted net income (loss) per common share	59,652,461		60,495,455		57,212,737
Diluted net income (loss) per common share	$	(0.93)	$	1.37	$	(1.21)

For the years ended December 31, 2022 and 2020, all outstanding potentially dilutive securities were excluded from the calculation as the effect of including such securities would have been anti-dilutive. For the year ended December 31, 2021, we excluded 1,196,268 shares of options and RSUs from the calculation of diluted net income per common share because the inclusion of such shares would have had an anti-dilutive effect.

Segment Reporting

The Company determines its segment reporting based upon the way the business is organized for making operating decisions and assessing performance. The Company has only one operating segment related to the development of pharmaceutical products.

Comprehensive Income (Loss)	12 Months Ended
Comprehensive Income (Loss)	Dec. 31, 2022
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 the years ended December 31, 2022, 2021, and 2020, the only component of other comprehensive income (loss) is net unrealized gain (loss) on marketable debt securities. There were no material reclassifications out of accumulated other comprehensive loss during the year ended December 31, 2022.

Marketable Debt and Equity Securities

12 Months Ended

Dec. 31, 2022

Marketable Securities [Abstract]

Marketable Debt and Equity Securities

The Company’s marketable debt securities held as of December 31, 2022 and 2021 are summarized below:


	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


	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
(in thousands)
Money Market Funds	$	123,892	$	—	$	—	$	123,892
Corporate Securities	144,584		—		(166)		144,418
Government Securities	311,148		1		(1,335)		309,814
	$	579,624	$	1	$	(1,501)	$	578,124

Reported as
Cash and cash equivalents							$	123,892
Marketable securities							454,232
Total investments							$	578,124

The maturities of the Company’s marketable debt securities as of December 31, 2022 are as follows:


	Amortized Cost		Estimated Fair Value
(in thousands)
Mature in one year or less	$	533,626	$	526,689
Mature within two years	3,831		3,826
	$	537,457	$	530,515

The unrealized losses on available-for-sale investments and their related fair values as of December 31, 2022 and 2021 are as follows:


	December 31, 2022
	Less than 12 months				12 months or greater
	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)


	December 31, 2021
	Less than 12 months				12 months or greater
	Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	50,337	$	(51)	$	45,872	$	(115)
Government Securities	39,909		(54)		254,593		(1,281)
	$	90,246	$	(105)	$	300,465	$	(1,396)

The unrealized losses from the listed securities are due to a change in the interest rate environment and not a change in the credit quality of the securities.

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). Equity securities with a readily determinable fair value and their fair values (in thousands) as of December 31, 2022 and 2021 are as follows:


	Fair Value December 31, 2022		Fair Value December 31, 2021
Astria Common Stock	$	9,529	$	3,449
INmune Common Stock	11,954		19,233
Viridian Common Stock	20,948		14,178
	$	42,431	$	36,860

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 evaluates 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. During the year ended December 31, 2022, the Company recorded an impairment charge of $0.1 million related to the Astria preferred stock. Equity securities without a readily determinable fair value and their carrying values (in thousands) as of December 31, 2022 and 2021 are as follows:


	Carrying Value December 31, 2022		Carrying Value December 31, 2021
Astria Preferred Stock	$	174	$	312
Zenas Preferred Stock	54,209		30,950
	$	54,383	$	31,262

In 2018, the Company received equity shares in Quellis Biosciences, Inc. (Quellis) in connection with a licensing transaction. In 2021, Quellis merged into Catabasis Pharmaceuticals, Inc. (Catabasis), and the Company received common and preferred stock in Catabasis in exchange for its Quellis equity. In June 2021, shares of the Catabasis preferred stock were exchanged for shares of Catabasis common stock; the shares of the Catabasis common stock have a readily determinable fair value. In September 2021, Catabasis changed its name to Astria Therapeutics, Inc. (Astria). The Company accounts for the shares in Astria common stock at their fair value each reporting period and the adjustment in the fair value of the Astria common stock has been recorded in unrealized gain (loss) on equity securities for the year ended December 31, 2022.

The Company records its investment in the shares of Astria preferred stock as an equity interest without a readily determinable fair value. The Company elected to record the original shares of preferred stock at their initial cost and to review the carrying value for impairment or other changes in carrying value at each reporting period. The Company subsequently recorded impairment charges of $0.1 million and $0.8 million related to its investment in Astria’s preferred stock in 2022 and 2021, respectively.

In 2017, the Company received shares of common stock of INmune Bio, Inc. (INmune) and an option to acquire additional shares of INmune’s common stock in connection with a licensing transaction. The Company received a second option to acquire additional shares of INmune common stock in connection with a designee appointed by us serving on the board of directors of INmune. The Company originally recorded its investment at cost pursuant to ASC 323, Investments – Equity Method and Joint Ventures. In June 2021, the Company entered into an Option Cancellation Agreement with INmune and received $15.0 million in proceeds and an additional shares of INmune common stock in exchange for the initial option. During 2021, the Company determined that it should no longer account for its investment in INmune under the equity method. In September 2021, the Company exercised its second option to purchase 108,000 shares of INmune common stock for $0.8 million and the Company recorded a gain of $0.9 million on the purchase. The Company's current share holdings, which consist of common stock of INmune, have a readily determinable fair value, and the adjustment in the fair value of the shares of INmune common stock was recorded in gain (loss) on equity securities for the year ended December 31, 2022.

In December 2021, the Company received shares of common stock of Viridian Therapeutics, Inc. (Viridian) in connection with the Viridian Agreement. In December 2022, the Company received additional shares of common stock of Viridian in connection with the Second Viridian Agreement (defined below). 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 in gain (loss) on equity securities for the year ended at December 31, 2022.

In 2020, the Company received an equity interest in Zenas BioPharma Limited (Zenas), in connection with the Zenas Agreement (defined below). 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 an identical or a similar investment of the same issuer. In 2021, the Company received a warrant to receive equity from Zenas in connection with the Second Zenas Agreement (defined below). In 2021, the Company purchased a convertible promissory note from Zenas. In 2022, the Zenas warrant was exchanged for additional equity in Zenas. In 2022, the convertible note and accrued interest through the conversion date were exchanged for equity shares in Zenas. We recognized an unrealized gain of $21.9 million from the warrant exchange and the conversion of the promissory note. During the year ended December 31, 2022, there was no impairment related to this investment.

Unrealized gains and losses recognized on equity securities (in thousands) during the year ended December 31, 2022 and 2021 consist of the following:


	Year Ended December 31,
	2022		2021

Net gains recognized on equity securities	$	23,434	$	39,289
Less: net gains recognized on equity securities redeemed	—		18,301
Unrealized gain (losses) recognized on equity securities	$	23,434	$	20,988

Sale of Additional Common Stock	12 Months Ended
Sale of Additional Common Stock	Dec. 31, 2022
Equity [Abstract]
Sale of Additional Common Stock	Sale of Additional Common StockUnder the terms of the Stock Purchase Agreement (defined below), Johnson & Johnson Innovation, JJDC, Inc. (JJDC), purchased $25.0 million of newly issued unregistered shares of the Company’s common stock, priced at a 30-day volume-weighted average price of $33.4197 per share as of October 1, 2021. The Company issued 748,062 shares of common stock to JJDC on November 12, 2021. The issued shares are subject to customary resale restrictions pursuant to Rule 144 of the Securities Act of 1933.

Property and Equipment

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment consist of the following:


	December 31,
	2022		2021
	(in thousands)
Computers, software and equipment	$	45,159	$	41,955
Furniture and fixtures	539		539
Leasehold and tenant improvements	41,774		8,574
Total gross carrying amount	87,472		51,068
Less accumulated depreciation and amortization	(28,289)		(22,828)
Total property and equipment, net	$	59,183	$	28,240

Leasehold and tenant improvements consist primarily of leasehold construction at our new Pasadena headquarters.

Depreciation expense related to property and equipment in 2022, 2021, and 2020 was $7.4 million, $6.3 million, and $4.7 million, respectively.

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

Our effective tax rate differs from the statutory federal income tax rate, primarily as a result of the changes in valuation allowance. The provision for income taxes for the year ended December 31, 2022 was $0.7 million.There was no provision for taxes for the years ended December 31, 2021 and December 31, 2020.

A reconciliation of the federal statutory income tax to our effective income tax is as follows (in thousands):


	Year Ended December 31,
	2022		2021		2020
Federal statutory income tax	$	(11,447)	$	17,352	$	(14,559)
State and local income taxes	(615)		783		(4,659)
Research and development credit	(9,366)		(10,492)		(9,669)
Stock-based compensation	3,384		2,424		529
Foreign-derived intangible income	(1,449)		—		—
Other	(74)		95		56
Change in state rate	44		2,599		—
Net change in valuation allowance	20,196		(12,761)		28,302
Income tax provision	$	673	$	—	$	—

The tax effect of temporary differences that give rise to a significant portion of the deferred tax assets and liabilities at December 31, 2022 and 2021 is presented below (in thousands):


	December 31,
	2022		2021
Deferred income tax assets
Net operating loss carryforwards	$	32,898	$	46,629
Research credits	54,825		48,128
Unrealized loss on securities	1,573		327
Capitalized lease assets	5,564		489
Accrued compensation	14,484		9,207
Capitalized research and development costs	21,338		—
Gross deferred income tax assets	130,682		104,780
Valuation allowance	(115,010)		(93,580)
Net deferred income tax assets	15,672		11,200
Deferred income tax liabilities
Patent costs	(2,885)		(3,416)
Deferred revenue	3,225		(3,508)
Licensing costs	(124)		(151)
Capitalized legal costs	(9)		(13)
Depreciation	(6,532)		(288)
Unrealized gain on securities	(9,347)		(3,824)
Gross deferred income tax liabilities	(15,672)		(11,200)
Net deferred income tax asset	$	—	$	—

The Tax Cuts and Jobs Act of 2017 (TCJA) was enacted in December 2017 and made substantial changes in the U.S. tax system. One of the changes was elimination of the AMT tax system for corporations and allowance of an income tax refund for AMT tax credit carryforwards. We have received an income tax refund of $0.8 million for the year ended December 31, 2020 for U.S. AMT credit carryforwards. The other significant change made by the TCJA requires research and development costs incurred after December 31, 2021 to be capitalized and amortized over several years. We have recorded a deferred asset as of December 31, 2022 for such capitalized research and development costs. We have net deferred tax assets relating primarily to net operating loss carryforwards and research and development tax credit carryforwards. Due to the uncertainty surrounding the realization of the benefits of our deferred tax assets in future tax periods, we have placed a valuation allowance against our deferred tax assets at December 31, 2022 and 2021. The Company recognizes valuation allowances to reduce deferred tax assets to the amount that is more likely than not to be realized. The Company’s net deferred income tax asset is not more likely than not to be realized due to the lack of sufficient sources of future taxable income and cumulative losses that have resulted over the years. During the year ended December 31, 2022, the valuation allowance increased by $21.4 million. The Company’s tax years starting in 2018 through 2021 remain open to potential examination by the U.S. and state taxing authorities due to carryforwards of net operating losses.

As of December 31, 2022, we had cumulative net operating loss carryforwards for federal and state income tax purposes of $102.4 million and $162.1 million, respectively, and available tax credit carryforwards of approximately $38.7 million for federal income tax purposes and $20.4 million for state income tax purposes, which can be carried forward to offset future taxable income, if any. The federal net operating loss carryforwards consist of $59.0 million of losses incurred prior to January 1, 2018, which are subject to carryforward limitations and $43.4 million of losses incurred after January 1, 2018, which may be carried forward indefinitely.

Our federal net operating loss carryforwards expire starting in 2027, state net operating loss carryforwards expire starting in 2035, and federal tax credit carryforwards begin to expire in 2034. Utilization of our net operating loss and tax credit carryforwards are subject to a substantial annual limitation under Section 382 of the Code due to the fact that we have experienced ownership changes. As a result of these changes, certain of our net operating loss and tax credit carryforwards may expire before we can use them.

- 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)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-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
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-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

Stock-Based Compensation

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Our Board of Directors and the requisite stockholders previously approved the 2010 Equity Incentive Plan (the 2010 Plan). In October 2013, our Board of Directors approved the 2013 Equity Incentive Plan (the 2013 Plan), and in November 2013, our stockholders approved the 2013 Plan. The 2013 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards, and other stock awards. The 2013 Plan became effective as of December 2, 2013, the date of the pricing of the Company’s initial public offering. 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.

As of December 31, 2022, the total number of shares of common stock available for issuance under the 2013 Plan was 14,792,799. 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 by 4% of the total number of issued and outstanding shares of common stock as of December 31 of the immediately preceding year. On January 1, 2022, the total number of shares of common stock available for issuance under the 2013 Plan was increased by 2,374,222 shares, which is included in the number of shares available for issuance above. As of December 31, 2022, a total of 14,535,306 options have been granted under the 2013 Plan.

As of December 31, 2022, the Company has awarded 1,999,817 RSUs to certain employees pursuant to the 2013 Plan. Vesting of these awards will be annually over equal installments, either a two or three-year vesting period, and is contingent on continued employment terms. 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.

In November 2013, our Board of Directors and stockholders approved the 2013 Employee Stock Purchase Plan (ESPP), which became effective as of December 5, 2013. Under the ESPP our employees may elect to have between 1-15% of their compensation withheld to purchase shares of the Company’s common stock at a discount. The ESPP had an initial two-year term that includes four six-month purchase periods, and employee withholding amounts may be used to purchase Company stock during each six-month purchase period. The initial two-year term ended in December 2015 and pursuant to the provisions of the ESPP, the second two-year term began automatically upon the end of the initial term. The total number of shares that can be purchased with the withholding amounts are based on the lower of 85% of the Company’s common stock price at the initial offering date or 85% of the Company’s stock price at each purchase date.

As of December 31, 2022, the total number of shares of common stock available for issuance under the ESPP is 539,392. Unless otherwise determined by our Board, beginning on January 1, 2014, and continuing until the expiration of the ESPP, the total number 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 our board, the total number of shares of common stock available for issuance under the ESPP was increased by 593,555 shares on January 1, 2022. As of December 31, 2022, we have issued a total of 635,449 shares of common stock under the ESPP.

Total employee, director and non-employee stock-based compensation expense recognized was as follows:


	Year Ended December 31,
(in thousands)	2022		2021		2020
General and administrative	$	17,281	$	12,813	$	10,769
Research and development	31,632		24,162		20,850
	$	48,913	$	36,975	$	31,619


	Year Ended December 31,
(in thousands)	2022		2021		2020
Stock options	$	29,758	$	27,909	$	26,045
ESPP	1,174		992		804
RSUs	17,981		8,074		4,770
	$	48,913	$	36,975	$	31,619

Information with respect to stock options outstanding is as follows:


	December 31,
	2022		2021		2020
Exercisable options	6,679,948		5,576,430		4,668,179
Weighted average exercise price per share of exercisable options	$	26.99	$	24.15	$	21.75
Weighted average grant date fair value per share of options granted during the year	$	15.45	$	21.65	$	16.96
Options available for future grants	3,622,319		3,597,371		3,346,092
Weighted average remaining contractual life	6.30		6.65		7.00

The following table summarizes stock option activity for the years ended December 31, 2022 and 2021:


	Number of Shares	Weighted- Average Exercise Price (Per Share)(1)		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)(2)
Balances at December 31, 2019	7,174,319	$	24.03	7.32	$	79,116
Options granted	1,679,324	33.08
Options forfeited	(243,384)	32.93
Options exercised(3)	(858,470)	19.36
Balances at December 31, 2020	7,751,789	26.23		7.00	$	134,941
Options granted	1,827,234	41.22
Options forfeited	(382,454)	36.15
Options exercised(3)	(520,240)	23.61
Balances at December 31, 2021	8,676,329	29.11		6.65	$	100,057
Options granted	2,135,233	29.45
Options forfeited	(533,435)	34.09
Options exercised(3)	(195,485)	18.46
Balances at December 31, 2022	10,082,642	$	29.12	6.30	$	27,141
As of December 31, 2022
Options vested and expected to vest	10,082,642	$	29.12	6.30	$	27,141
Exercisable	6,679,948	$	26.99	5.10	$	26,979

______________________________

(1)The weighted average exercise price per share is determined using exercise price per share for stock options.

(2)The aggregate intrinsic value is calculated as the difference between the exercise price of the option and the fair value of our common stock for in-the-money options at December 31, 2022 and 2021.

(3)The total intrinsic value of stock options exercised was $1.6 million, $9.2 million, and $16.3 million for the years ended December 31, 2022, 2021 and 2020 respectively.

We estimated the fair value of employee and non-employee awards using the Black-Scholes valuation model. The fair value of employee stock options is being amortized on a straight-line basis over the requisite service period of the awards. Management estimates the probability of non-employee awards being vested based upon an evaluation of the non-employee achieving their specific performance goals.

Options are issued at the fair market value of our stock on the date of grant.

The fair value of employee stock options was estimated using the following weighted average assumptions for the years ended December 31, 2022, 2021 and 2020:


	Options
	2022	2021	2020
Common stock fair value per share	$19.74 - 38.08	$30.65- 49.47	$20.69 - 45.91
Expected volatility	51.51% - 54.36%	53.91% - 56.82%	52.93% - 58.95%
Risk-free interest rate	1.57% - 4.34%	0.47% - 1.33%	0.29% - 1.71%
Expected dividend yield	—	—	—
Expected term (in years)	6.00 - 7.65	6.00 - 7.65	5.23 - 7.65


	ESPP
	2022	2021	2020
Expected term (years)	0.5 - 2.0	0.5 - 2.0	0.5 - 2.0
Expected volatility	43.19% - 55.72%	46.08% - 66.37%	50.77% - 66.37%
Risk-free interest rate	0.13% - 4.72%	0.04% - 1.65%	0.09% - 1.65%
Expected dividend yield	—	—	—

The expected term of stock options represents the average period the stock options are expected to remain outstanding. The expected stock price volatility for our stock options for the years ended December 31, 2022, 2021, and 2020 was determined using a blended volatility by examining the historical volatility for industry peer companies and the volatility of our stock from the effective date that our shares were publicly traded on a national stock exchange.

We determined the average expected life of stock options based on the anticipated time period between the measurement date and the exercise date by examining the option holders’ past exercise patterns.

The risk-free interest rate assumption is based on the U.S. Treasury instruments, for which the term was consistent with the expected term of our stock options.

The expected dividend assumption is based on our history and expectation of dividend payouts. We have not paid dividends and did not have any dividend payout at December 31, 2022.

The following table summarizes RSU activity for the years ended December 31, 2022:


	Number of Shares	Weighted- Average Grant Date Fair Value (Per Unit)
Unvested at December 31, 2019	90,006	$	34.66
Granted	348,288	32.51
Vested	(62,355)	32.61
Forfeited	(17,114)	32.33
Unvested at December 31, 2020	358,825	$	33.04
Granted	670,700	39.11
Vested	(151,555)	32.76
Forfeited	(51,822)	36.68
Unvested at December 31, 2021	826,148	$	37.79
Granted	875,330	29.45
Vested	(341,073)	37.37
Forfeited	(127,854)	33.66
Unvested at December 31, 2022	1,232,551	$	32.41

As of December 31, 2022 and 2021, the unamortized compensation expense related to unvested stock options was $52.6 million and $54.5 million, respectively. The remaining unamortized compensation expense will be recognized over the next 2.43 years. At December 31, 2022 and 2021, the unamortized compensation expense was $1.2 million and $2.3 million respectively under our ESPP. The remaining unamortized expense will be recognized over the next 0.94 years. At December 31, 2022 and 2021, the unamortized compensation expense related to unvested restricted stock units was $28.3 million and $24.8 million, respectively. The remaining unamortized compensation expense will be recognized over the next 1.90 years.

Leases

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Leases

The Company leases office and laboratory space in Monrovia, California under two separate leases that expire in January 2023 and December 2025, respectively 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 lease term extension option. For the year ended December 31, 2022, ROU assets obtained in exchange for new operating lease liabilities are $0.3 million.

The Company leases additional office space in San Diego, California through August 2022, with an option to extend for an additional five years. In May 2022, the Company entered into an amendment to the lease to extend the lease term through December 31, 2023. The Company has assessed that it is unlikely to exercise the option to extend the lease term.

In June 2021, the Company entered into an 18-month lease for office space in Monrovia, California. The lease began August 1, 2021 and terminated January 31, 2023. ROU assets obtained in exchange for new operating lease liabilities are $0.3 million

In June 2021, the Company entered into an Agreement of Lease (the Halstead Lease) relating to 129,543 rentable square feet, for laboratory and office space, in Pasadena, California, where the Company intends to move its corporate headquarters in the first quarter of 2023. The term of the Halstead Lease will become effective in two phases. The first phase commences on July 14, 2021 and encompasses 83,083 square feet while the second phase commences no later than July 1, 2025 and encompasses an additional 46,460 square feet. The term of the Halstead Lease is 13 years from the first phase commencement date. The Company received delivery of the first phase premises on July 1, 2021 and is scheduled to complete construction of office, laboratory, and related improvements in the second half of 2022. The Halstead Lease provides the Company with improvement allowances of up to $17.0 million and $3.3 million in connection with the Phase 1 and Phase 2 building improvements, respectively. The initial base monthly rent is $386,336, or $4.65 per square foot, and

includes increases of three percent annually. The Company will also be responsible for its proportionate share of operating expenses, tax expense, and utility costs.

In July 2021, the Halstead Lease was amended to clarify the start date of the new lease to August 1, 2022 and to amend other provisions of the Halstead Lease to reflect the new start date of the lease. In August 2022, the Halstead lease was amended to increase the amount of the tenant allowance by$5.0 million with a corresponding increase in total rental payments. The Company is eligible to receive total tenant allowance under the lease for the phase 1 space of $22.0 million and the initial base rent is increased to $416,246 , or $5.01 per square foot. For the year ended December 31, 2021, ROU assets obtained in exchange for new operating lease liabilities are $29.7 million.

The Company received delivery of the second phase premises on December 1, 2022. For the year ended December 31, 2022, ROU assets obtained in exchange for new operating lease liabilities are $15.3 million.

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 December 31, 2022 to the operating lease liabilities recorded on the balance sheet (in thousands):


Years ending December 31,
2023	$	6,558
2024	6,072
2025	7,392
2026	8,589
2027	8,829
Thereafter	75,512
Total undiscounted lease payments	112,952
Less: Tenant allowance	(5,459)
Less: Imputed interest	(47,859)
Present value of lease payments	$	59,634

Lease liabilities - short-term	$	4,708
Lease liabilities - long-term	54,926
Total lease liabilities	$	59,634

The following table summarizes lease costs, cash, and other disclosures for the years ended December 31, 2022, 2021, and 2020 (in thousands):


	Year Ended December 31,
	2022			2021			2020

Operating lease cost	$	6,588		$	4,342		$	2,503
Variable lease cost	506			58			150
Total lease costs	$	7,094		$	4,400		$	2,653
Cash paid for amounts included in
the measurement of lease liabilities	$	2,869		$	2,773		$	2,233
Weighted-average remaining lease term
—operating leases (in years)	12.0			12.3			7.4
Weighted-average discount rate
—operating leases	8.9		%	5.8		%	5.5		%

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contingencies From 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. We are 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 our balance sheet. We have also entered into agreements with third party vendors which will require us to make future payments upon the delivery of goods and services in future periods. Guarantees In the normal course of business, we indemnify certain employees and other parties, such as collaboration partners and other parties that perform certain work on behalf of, or for the Company or take licenses to our technologies. We have agreed to hold these parties harmless against losses arising from our breach of representations or covenants, intellectual property infringement or other claims made against these parties in performance of their work with us. These agreements typically limit the time within which the party may seek indemnification by us and the amount of the claim. It is not possible to prospectively determine the maximum potential amount of liability under these indemnification agreements since we have not had any prior indemnification claims on which to base the calculation. Further, each potential claim would be based on the unique facts and circumstances of the claim and the particular provisions of each agreement. We are not aware of any potential claims and we did not record a liability as of December 31, 2022 and 2021.

Collaboration and Licensing Agreements

12 Months Ended

Dec. 31, 2022

Collaboration and Licensing Agreements

Collaboration and Licensing Agreements

Following is a summary description of the material revenue arrangements, including arrangements that generated revenue in the period ended December 31, 2022, 2021, and 2020. The revenue reported for each agreement has been adjusted to reflect the adoption of ASC 606 for each period presented.

Aimmune Therapeutics, Inc.

In 2020, the Company entered into a License, Development and Commercialization Agreement (the Aimmune Agreement) with Aimmune Therapeutics, Inc. (Aimmune) pursuant to which the Company granted Aimmune an exclusive worldwide license to XmAb7195, which was renamed AIMab7195. The Company received an upfront payment and is eligible to receive development, regulatory and, sales and tiered royalties on net sales of approved products from high-single to mid-teen percentage range.

No revenue was recognized for the year ended December 31, 2022 and 2021. There is no deferred revenue as of December 31, 2022 or 2021 related to this agreement.

Alexion Pharmaceuticals, Inc.

In January 2013, the Company entered into an option and license agreement with Alexion Pharmaceuticals, Inc. (Alexion). Under the terms of the agreement, the Company granted to Alexion an exclusive research license, with limited sublicensing rights, to make and use our Xtend technology. Alexion exercised its rights to include our technology in ALXN1210, which is now marketed as Ultomiris.

The Company is eligible to receive contractual milestones for certain commercial achievements, and the Company is also entitled to receive royalties based on a percentage of net sales of such products sold by Alexion, its affiliates, or its sub licensees, 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.

In 2020, Alexion completed certain regulatory submissions for Ultomiris, and the Company received a total of $10.0 million in milestone payments. During 2020, the Company also recorded royalty revenue of $16.2 million in connection with reported net sales of Ultomiris by Alexion.

In 2021, the Company recorded royalty revenue of $22.2 million on net sales.

In 2022, the Company recorded royalty revenue of $29.4 million on net sales.

The total revenue recognized under this arrangement was $29.4 million, $22.2 million, and $26.2 million for the years ended December 31, 2022, 2021, and 2020, respectively. As of December 31, 2022, there is a receivable of $14.8 million, and there is no deferred revenue related to this agreement.

Amgen Inc.

In September 2015, the Company entered into a research and license agreement (the Amgen Agreement) with Amgen Inc. (Amgen) to develop and commercialize bispecific antibody product candidates using the Company’s proprietary XmAb® bispecific Fc technology. Amgen has advanced one of the discovery programs, now AMG509, into clinical development. The Company is eligible to receive future development, regulatory and sales milestones in total for the program and is eligible to receive royalties on any global net sales of products.

No revenue was recognized for the year ended December 31, 2022, 2021, or 2020. As of December 31, 2022, there was no deferred revenue related to the arrangement.

Astellas Pharma Inc.

Effective March 2019, the Company entered into a Research and License Agreement (Astellas Agreement) with Astellas Pharma Inc. (Astellas) pursuant to which the Company and Astellas conducted a discovery program to characterize compounds and products for development and commercialization. Under the Astellas Agreement, Astellas was granted a worldwide exclusive license, with the right to sublicense products in the field created by the research activities.

The Company received an upfront payment and is eligible to receive development, regulatory and sales milestones. If commercialized, the Company is eligible to receive royalties on net sales that range from the high-single to low-double digit percentages.

Astellas has advanced an antibody that was delivered into development, and we received a milestone related to the candidate in 2020. Astellas advanced the candidate into Phase 1 studies in 2022 and we received a $5.0 million milestone. The Company recognized $2.5 million of revenue in 2020, and $5.0 million of revenue in 2022 under the agreement. There is no deferred revenue as of December 31, 2022.

Astria Therapeutics, Inc.

In May 2018, the Company entered into an agreement with Quellis, pursuant to which the Company provided Quellis a non-exclusive license to its Xtend Fc technology. The Company received an equity interest in Quellis and is eligible to receive development, regulatory and sales milestones. The Company is also eligible to receive royalties in the mid-single digit percentage range on net sales of approved products.

In January 2021, Quellis merged into Catabasis, and the Company received common stock and preferred stock of Catabasis in exchange for its equity in Quellis. The Company recognized an increase in the fair value of its equity interest for the exchange of shares, which was recorded as unrealized gain for the three months ended March 31, 2021. In June 2021, a portion of the Company’s preferred stock in Catabasis was converted to common stock, which was recorded at its fair value as of June 30, 2021. The remaining Catabasis preferred stock is carried at its original cost and is reviewed for impairment or other changes at each reporting period. In September 2021, Catabasis changed its name to Astria. The Company recorded an impairment charge of $0.1 million for its investment in Astria preferred stock for the year ended December 31, 2022.

The Company recognized unrealized gain of $6.1 million and $4.5 million related to its equity interest in Astria for the years ended December 31, 2022 and 2021, respectively. There is no deferred revenue as of December 31, 2022 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. Hoffman-La Roche Ltd (collectively, Genentech) for the development and commercialization of novel IL-15 collaboration products (Collaboration Products), including XmAb306, the Company’s IL-15/IL15Rα-Fc candidate.

Under the terms of the Genentech Agreement, Genentech received an exclusive worldwide license to XmAb306 and Genentech and Xencor will jointly collaborate on worldwide development of XmAb306.

The Company determined that the transaction price of the Genentech Agreement at inception was $120.0 million consisting of the upfront payment, and allocated the transaction price to each of the separate performance obligations using the relative standalone selling price with $111.7 million allocated to the license to XmAb306, $4.1 million allocated to the additional program and $4.2 million allocated to the research services.

The Company recognized the $111.7 million allocated to the license when it satisfied its performance obligation and transferred the license to Genentech in March 2019, and the $8.3 million allocated to the research activities was recognized over a period of time through the end of the research term or the time that a program is delivered to Genentech. The research term expired in the first half of 2021, and the balance in deferred revenue related to the Genentech Agreement was recognized as the Company is no longer required to render services.

No revenue was recognized for the year ended December 31, 2022. For the years ended December 31, 2021 and 2020, we recognized $2.5 million and $3.5 million of income, respectively, from the Genentech Agreement. As of December 31, 2022, there was a $0.2 million receivable related to cost-sharing development activities during the fourth quarter of 2022. There is no deferred revenue as of December 31, 2022.

Gilead Sciences, Inc.

In January 2020, the Company entered into a Technology License Agreement (the Gilead Agreement) with Gilead Sciences, Inc. (Gilead), in which the Company provided Gilead an exclusive license to its Cytotoxic Fc and Xtend Fc technologies for an initial identified antibody and options for up to three additional antibodies directed to the same molecular target. Gilead is responsible for all development and commercialization activities for all target candidates. The Company received an upfront payment and is eligible to receive development, regulatory and, sales milestones for each product incorporating the antibodies selected. In addition, the Company is eligible to receive royalties in the low-single digit percentage range on net sales of approved products.

In the second quarter of 2020, Gilead exercised options on three additional antibody compounds, and in April 2020, we received a total of $7.5 million in payment of the three options.

No revenue was recognized for the year ended December 31, 2022 and 2021. The Company recognized $13.5 million of revenue related to the Gilead Agreement for the year ended December 31, 2020. There is no deferred revenue as of December 31, 2022 related to this agreement.

INmune Bio, Inc.

In October 2017, the Company entered into a License Agreement (the INmune Agreement) with INmune. Under the terms of the INmune Agreement, the Company provided INmune with an exclusive license to certain rights to a proprietary protein, XPro1595. In connection with the agreement the Company received shares of INmune common stock and an option to acquire additional shares of INmune. The Company also received a second option to acquire additional shares of INmune common stock with a designee appointed by us serving on the board of directors of INmune.

The Company initially recorded its equity interest in INmune, including its option to acquire additional INmune shares, at cost pursuant to ASC 323.

In June 2021, the Company entered into the First Amendment to License Agreement (the Amended INmune Agreement) and an Option Cancellation Agreement (the Option Agreement) with INmune. The Amended INmune

Agreement modified certain diligence provisions in the INmune Agreement with no change in total consideration or performance obligations. The Option Agreement provided for the sale of the initial option to INmune for the total consideration of $18.3 million which includes $15.0 million in cash and additional shares of INmune common stock. The Company recorded a realized gain of $18.3 million according to ASC 860, Transfer and Servicing, and recorded the additional shares of INmune common stock according to ASC 321, Investments – Equity Securities.

During the three months ended June 30, 2021, the Company determined that it should no longer record its investment in INmune under the equity method and recorded its investment in INmune pursuant to ASC 321. The Company adjusted the carrying value of this investment by recognizing an unrealized gain of $27.8 million as other income for the three months ended June 30, 2021.

In September 2021, the Company exercised its second to purchase additional shares of INmune common stock for $0.8 million. The Company recognized an unrealized gain of $2.0 million, which consists of $1.1 million of fair value of the option and $0.9 million gain on the purchase, as other income for the three months ended September 30, 2021.

For the year ended December 31, 2022, the Company recorded $7.3 million of unrealized loss related to its investment in INmune. For the year ended December 31, 2021, the Company recorded $15.1 million of unrealized gain and $18.3 million of realized gain related to its investment in INmune. No revenue was recognized for the years ended December 31, 2022, 2021, or 2020.

At the inception of the INmune Agreement in 2017, INmune was a related party as a result of the Company's significant influence with respect to its investment in INmune, as determined under ASC 323. The Company did not have any amounts due to or from INmune at December 31, 2022 or 2021. At June 30, 2021, the Company determined that it no longer has a significant influence in INmune and that INmune is no longer a related party.

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 Xencor and Janssen conducted research and development activities to discover novel CD28 bispecific antibodies for the treatment of prostate cancer. Janssen and Xencor will conducted joint research activities to discover XmAb bispecific antibodies against CD28 and against an undisclosed prostate tumor-target with Janssen maintaining exclusive worldwide rights to develop and commercialize Licensed Products identified from the research activities.

Under the Janssen Agreement, the Company will conduct research activities and apply its bispecific Fc technology to antibodies targeting prostate cancer provided by Janssen. Upon completion of the research activities Janssen will have a candidate selection option to advance an identified candidate for development and commercialization. The activities will be conducted under a research plan agreed to by both parties. Janssen will assume full responsibility for development and commercialization of the CD28 bispecific antibody candidate. Pursuant to the Janssen Agreement, the Company received an upfront payment and is eligible to receive development, regulatory and, sales milestones. If commercialized, the Company is eligible to receive royalties on net sales that range from the high-single to low-double digit percentages.

Pursuant to the Janssen Agreement, upon development of a bispecific candidate by Janssen through proof of concept, we have the right to opt-in to fund 20% of development costs and to perform 30% of detailing efforts in the U.S. If we exercise this right, we will be eligible to receive tiered royalties in the low-double digit to mid-teen percentage range.

The Company allocated the transaction price to the single performance obligation, delivery of CD28 bispecific antibodies to Janssen.

The Company recognized the $50.0 million transaction price as it satisfied its performance obligation to deliver CD28 bispecific antibodies to Janssen. The Company recognized revenue related to the performance obligation over the expected period of time to complete and deliver the CD28 bispecific antibodies to Janssen using the expected input method which considers an estimate of the Company’s efforts to complete the research activities outlined in the Janssen Agreement.

In November 2021, the Company completed its performance obligations under the research activities and delivered CD28 bispecific antibodies to Janssen. In December 2021, Janssen selected a bispecific CD28 candidate for further development, and we received a milestone of $5.0 million. For the year ended December 31, 2021 the Company recognized as revenue the $50.0 million transaction price in connection with the completion of the research activities and the $5.0 million milestone for selection of an antibody candidate by Janssen. No revenue was recognized under this agreement in 2022.

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 Agreement became effective on November 5, 2021.

Pursuant to the Second Janssen Agreement, the Company received an upfront payment of $100.0 million and is eligible to receive up to $1,187.5 million in milestones which include $289.4 million in development milestones, $378.1 million in regulatory milestones and $520.0 million in sales milestones. Under the terms of the Stock Purchase Agreement, Johnson & Johnson Innovation, JJDC, Inc. (JJDC), agreed to purchase $25.0 million of newly issued unregistered shares of the Company’s common stock, priced at a 30-day volume-weighted average price of $33.4197 per share as of October 1, 2021. The Company issued JJDC 748,062 shares of its common stock which had a fair market value of $28.9 million when the shares were transferred.

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.

Under the Second Janssen Agreement, the Company granted Janssen an exclusive worldwide right to its plamotamab program and the Company will conduct research activities and apply its CD28 bispecific Fc technology to antibodies targeting B-cells. Upon completion of the research activities Janssen will have options to advance up to four identified candidates for development and commercialization. The activities will be conducted under a research plan agreed to by both parties. Janssen will assume full responsibility for development and commercialization of the CD28 bispecific antibody candidate. If commercialized, the Company is eligible to receive royalties on net sales that range from the high-single to low-double digit percentages.

The Company evaluated the Second Janssen Agreement under the provisions of ASC 606. We have determined that Janssen is a customer for purposes of the delivery of specific performance obligations under the Second Janssen Agreement and applied the provisions of ASC 606 to the transaction.

The Company identified the following performance obligations under the Second Janssen Agreement:

(i)the license to the plamotamab program, and

(ii)research services during a two-year period to create up to four CD28 bispecific candidates targeting B-cell antigens.

The Company determined that the license and the research services are separate performance obligations because they are capable of being distinct and are distinct in the context of the Second Janssen Agreement. The license to plamotamab has standalone functionality as Janssen has exclusive worldwide rights to the program, including the right to sublicense to third parties. Janssen has significant experience and capabilities in developing and commercializing drug candidates similar to plamotamab, and Janssen is capable of performing these activities without the Company’s involvement. Upon the transfer of the license of plamotamab and the related data and materials, Janssen could develop and

commercialize plamotamab without further assistance from the Company. The Company determined that the research services for potential CD28 candidates was a separate standalone performance obligation. The Second Janssen Agreement provides an outline of an integrated research plan for the programs to be conducted by the two companies, and the research activities are separate and distinct from the license to plamotamab.

The Company determined the standalone selling price of the license to be $58.5 million using the adjusted market assessment approach considering similar collaboration and license agreements and transactions. The standalone selling price for the research services to be performed during the research term was determined to be $37.6 million using the market approach which was derived from the Company’s experience and information from providing similar research services.

The Company determined that the transaction price of the Second Janssen Agreement at inception was $96.1 million consisting of the $100.0 million upfront payment reduced by the $3.9 million discount on the proceeds received from the sale of Company common stock to Janssen. The potential milestones are not included in the transaction price as these are contingent on future events and the Company would not recognize these in revenue until it is not probable that these would not result in significant reversal of revenue amounts in future periods. The Company will re-assess the transaction price at each reporting period and when event outcomes are resolved or changes in circumstances occur.

The Company allocated the transaction price to each of the separate performance obligations using the relative standalone selling price with $58.5 million allocated to the license to the plamotamab program and $37.6 million allocated to the research services.

The Company recognized the $58.5 million allocated to the license when it satisfied its performance obligation and transferred the license to Janssen in November 2021. The license was transferred upon the effective date of the Second Janssen Agreement and when the Company subsequently transferred certain data related to the program to Janssen. The $37.6 million allocated to the research services is being recognized over a period of time through the end of the research term that services are rendered as we determine that the input method is the appropriate approach to recognize income for such services. A total of $7.0 million and $0.3 million of revenue related to the research services was recognized in each of the years ended December 31, 2022 and December 31, 2021, respectively.

The Company recognized $7.0 million and $113.8 million of revenue related to the two Janssen agreements for the years ended December 31, 2022 and 2021, respectively. No revenue was recognized under this arrangement for the year ended December 31, 2020. There is $30.3 million in deferred revenue as of December 31, 2022 related to our obligation to complete research activities and deliver CD28 bispecific antibodies under 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 in March 2012 and in 2020. The agreement provides MorphoSys with an exclusive worldwide license to the Company’s patents and know-how to research, develop, and commercialize the Company’s 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 a total of $7.8 million of royalty revenue on net sales of Monjuvi for the year ended December 31, 2022. The Company recognized a total of $12.5 million of milestone revenue related to clinical studies and royalties of $5.9 million on net sales of Monjuvi for the year ended December 31, 2021. There was $39.0 million of revenue recognized under this arrangement for the year ended December 31, 2020. As of December 31, 2022, the Company has no deferred revenue related to this agreement and has recorded a receivable of $2.2 million for royalties due.

Novartis Institute for Biomedical Research, Inc.

In June 2016, the Company entered into a Collaboration and License Agreement (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 granted Novartis certain exclusive rights to research, develop and commercialize XmAb14045 (vibecotamab) and,

•The Company will provide Novartis with a non-exclusive license to certain of its Fc technologies to apply against up to ten targets identified by Novartis.

In August 2021, Novartis notified the Company it was terminating its rights with respect to the vibecotamab program, which will be effective in February 2022. Under the Novartis Agreement, Novartis is responsible for its share of vibecotamab development costs through August 2022.

We completed delivery of two Global Discovery Programs under the Agreement.

Under ASC 606, revenue is recognized at the time that the Company’s performance obligation for each Global Discovery is completed upon delivery of each discovery program to Novartis. The Company delivered two discovery programs to Novartis and recognized $40.1 million of revenue in the period that each program was delivered. The Company’s obligations to provide research services under the Agreement for additional Global Discovery Programs expired in 2021, and we recognized $40.1 million of research revenue from deferred revenue.

In June 2021, Novartis selected an Fc candidate and received a non-exclusive license to the Company’s Fc technology. Novartis will assume full responsibility for development and commercialization of the licensed Fc product candidate. The Company is eligible to receive development, clinical, and sales milestones and royalties on net sales of approved products for the licensed Fc candidate. During the year ended December 31, 2021, Novartis advanced the Fc candidate into development and initiated clinical studies and the Company recognized $3.0 million of revenue related to the milestones.

During the year ended December 31, 2021, the Company recognized $43.1 million of revenue. No revenue was recognized during the years ended December 31, 2022 and 2020. There was a $0.03 million receivable and no deferred revenue as of December 31, 2022 related to the arrangement.

Omeros Corporation

In August 2020, the Company entered into a Technology License Agreement (the Omeros Agreement) with Omeros Corporation (Omeros), in which the Company provided Omeros a non-exclusive license to its Xtend Fc technology, an exclusive license to apply its Xtend technology to an initial identified antibody and options to apply its Xtend technology to three additional antibodies. Omeros is responsible for all development and commercialization activities for all target candidates. The Company received an upfront payment and is eligible to receive development, regulatory and, sales milestones for each product incorporating the antibodies selected. In addition, the Company is eligible to receive royalties in the mid-single digit percentage range on net sales of approved products.

There was no revenue recognized for the year ended December 31, 2022 and 2021. The Company recognized $5.0 million of revenue related to the Omeros Agreement for the year ended December 31, 2020. There is no deferred revenue as of December 31, 2022 related to this agreement.

Vir Biotechnology, Inc.

In 2019, the Company entered into a Patent License Agreement (the Vir Agreement) with Vir Biotechnology (Vir) pursuant to which the Company provided a non-exclusive license to its Xtend technology for up to two targets. Under the terms of the Vir Agreement, the Company received a total of $2.0 million in upfront and milestone payments and is eligible to receive additional milestones of $154.0 million which include $4.0 million of development milestones, $30.0 million of regulatory milestones and $120.0 million of sales milestones. In addition, the Company is eligible to receive royalties on the net sales of approved products in the low-single digits.

Vir initiated a Phase 1 study with a licensed antibody in 2019, and in the second quarter of 2020, it initiated a Phase 1 study with a second licensed antibody.

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 novel antibodies Vir is investigating as potential treatments for patients with COVID-19. Under the terms of the Second Vir Agreement, Vir is responsible for all research, development, regulatory and commercial activities for the antibody, and the Company is eligible to receive royalties on the net sales of approved products in the mid-single digit percentage range. Vir and its marketing partner, GSK, began recording sales for sotrovimab beginning in June 2021. In 2022 and 2021, we recognized royalty revenue of $114.9 million and $52.2 million, respectively related to this agreement.

In February 2021, the Company entered into the Vir Amendment No. 1 to the Vir Agreement and the Vir Amendment No. 1 to the Second Vir Agreement (collectively, the Vir Amendments), in each case, pursuant to which the Company provided a non-exclusive license to additional Fc technology for the targets previously identified in the Vir Agreement and the Second Vir Agreement, respectively. If Vir incorporates additional Fc technologies in the identified targets, the Company is eligible to receive additional royalties on net sales of approved products from low to mid-single digit range.

The Company determined that the Second Vir Agreement and the Vir Amendments were modifications of the original Vir Agreement, and that the transfer of the license occurred at inception of the Vir Agreement. The total consideration under the arrangement did not change with the Second Vir Agreement or the Amendments as the Company will potentially receive additional royalty revenue which is variable consideration and is not included in the transaction price.

In June 2021, Vir announced its plan to initiate a Phase 2 study for VIR-3434 and subsequently completed dosing of the first patient in such study in July 2021. The Company recorded a $0.5 million contract asset in connection with this milestone event, and the payment was received in August 2021.

The Company recognized $115.4 million, $52.7 million, and $0.3 million of revenues related to the agreement for the years ended December 31, 2022, 2021, and 2020, respectively. There is no deferred revenue as of December 31, 2022 related to this agreement. As of December 31, 2022, the Company has recorded a receivable of $4.8 million for royalties due related to this agreement.

Viridian Therapeutics, Inc.

In December 2020, we entered into a Technology License Agreement (Viridian Agreement) with Viridian Therapeutics, Inc. (Viridian), in which we provided Viridian a non-exclusive license to our Xtend Fc technology and an exclusive license to apply our Xtend Fc technology to antibodies targeting IGF-1R. Viridian is responsible for all development and commercialization activities. We received an upfront payment of shares of Viridian common stock valued at $6.0 million and are eligible to receive development, regulatory and sales milestones. We are also eligible to receive royalties in the mid-single digit percentage range on net sales of approved products.

The Company allocated $6.0 million of the transaction price to the licenses to the Xtend Fc technology and recognized income for the licenses at inception of the arrangement when Viridian began benefiting access to it.

In December 2021, we entered into a second Technology License Agreement (Second Viridian Agreement) with Viridian for a non-exclusive license to certain antibody libraries developed by us. Under the Second Viridian Agreement, Viridian received a one-year research license to review the antibodies and the right to select up to three antibodies for further development. Viridian is responsible for all further development of the selected antibodies. We received an upfront payment shares of Viridian common stock valued at $7.5 million and are eligible to receive up to $24.8 million in milestones, which include $1.8 million in development milestones, $3.0 million in regulatory milestones and $20.0 million in sales milestones in addition to royalties on net sales of approved products under the Second Viridian Agreement.

The Company evaluated the Second Viridian Agreement under the revenue recognition standard ASC 606 and identified the following performance obligation that it deemed to be distinct at the inception of the contract:

•non-exclusive license to certain antibody libraries created by the Company

The Company considered the license as functional intellectual property as Viridian has the right to use the materials and license at the time that the Company transfers such rights.

The total transaction price is $7.5 million, which includes the upfront payment of Viridian common stock at their fair value at the date of the Agreement. The milestone payments are variable consideration to which the Company applied the “most likely amount” method and concluded at inception of the Viridian Agreement it is unlikely that the Company will collect such payments. The milestone payments were not included in the transaction price, and the Company will review this conclusion and update at each reporting period.

The Company allocated $7.5 million of the transaction price to the licenses to the antibody libraries and recognized income for the licenses at inception of the arrangement when Viridian received the materials and began accessing them.

No revenue related to the Viridian Agreement was recognized for the year ended December 31, 2022. The Company recognized $7.5 million and $6.0 million of revenue related to the Viridian Agreement for the years ended December 31, 2021 and 2020, respectively. There is no deferred revenue as of December 31, 2022 related to this agreement.

Zenas BioPharma Limited

In November 2020, the Company entered into a License Agreement (Zenas Agreement) with Zenas BioPharma Limited (Zenas) pursuant to which the Company granted Zenas exclusive worldwide rights to develop and commercialize to three preclinical-stage Fc-engineered drug candidates: XmAb6755, Xpro9523, and XmAb10171. Under the Zenas Agreement, Zenas will be responsible for all further development and commercialization activities for XmAb6755, Xpro9523, and XmAb10171. The Company received a 15% equity interest in Zenas with a fair value of $16.1 million, and the Company is eligible to receive royalties on net sales of approved products in the mid-single digit to mid-teen percentage range.

Under the Zenas Agreement, Zenas received exclusive worldwide rights to manufacture, develop and commercialize XmAb6755, Xpro9523, and XmAb10171. Zenas also received the rights to all data, information, and research materials related to the three preclinical stage programs.

The Company evaluated the Zenas Agreement under the revenue recognition standard ASC 606 and identified the following performance obligations that it deemed to be distinct at the inception of the contract:

•exclusive license to the XmAb6755, Xpro9523, and XmAb10171 drug candidates; and

•rights to material, data, and information that the Company had accumulated in connection with conducting preclinical activities for each of the three programs and intellectual property filings and information.

The Company considered the licenses as functional intellectual property as Zenas has the right to use each of XmAb6755, Xpro9523 and XmAb10171 at the time that the Company transfers such rights. The rights to the preclinical programs’ data are not considered to be separate from the license to programs as Zenas cannot benefit from the license without the supporting data and documentation.

The total transaction price is $16.1 million, which includes the upfront payment of 15% of the equity of Zenas at its fair value at the date of the Zenas Agreement. The Zenas Agreement includes variable consideration for potential future royalties that were contingent on future success factors for the licensed programs. The Company used the “most likely amount” method to determine the variable consideration. None of the royalties were included in the transaction price. The Company will re-evaluate the transaction price in each reporting period as uncertain events are resolved or other changes in circumstances occur.

The Company determined the transaction price at inception of the Zenas Agreement and allocated it to the performance obligation, delivery of the XmAb6755, Xpro9523, and XmAb10171 licenses.

The Company completed delivery of its performance obligations in December 2020. The licenses to XmAb6755, Xpro9523, and XmAb10171 were transferred to Zenas at inception of the Zenas Agreement, and the related research data and documentation was transferred to Zenas in December 2020.

In November 2021, the Company entered into a second License Agreement (Second Zenas Agreement) with Zenas, in which we licensed the exclusive worldwide rights to develop and commercialize the Company’s obexelimab (XmAb5871) drug candidate. Under the Second Zenas Agreement, Zenas will be responsible for all further development

and commercialization activities for obexelimab. The Company received a warrant to acquire additional equity in Zenas with a fair value of $14.9 million, and the Company is eligible to receive royalties on net sales of approved products in the mid-single digit to mid-teen percentage range. We are also eligible to receive up to $470.0 million based on the achievement of certain clinical development, regulatory and commercialization milestones and are eligible to receive tiered, mid-single digit to mid-teen percent royalties upon commercialization of obexelimab, dependent on geography. Zenas will have sole responsibility for advancing the research, development, regulatory and commercial activities of obexelimab worldwide.

The Company evaluated the Second Zenas Agreement under the revenue recognition standard ASC 606 and identified the following performance obligations that it deemed to be distinct at the inception of the contract:

•exclusive license to the obexelimab drug candidate; and

•rights to material, data, and information that the Company had accumulated in connection with conducting clinical activities for the program and intellectual property filings and information.

The Company considered the license as functional intellectual property as Zenas has the right to use obexelimab at the time that the Company transfers such rights. The rights to the obexelimab program data are not considered to be separate from the license to program as Zenas cannot benefit from the license without the supporting data and documentation.

The total transaction price is $14.9 million, which includes the upfront payment of a warrant to acquire up to 15% of the equity of Zenas in connection with a future financing at its fair value at the date of the Second Zenas Agreement. The Second Zenas Agreement includes variable consideration for potential future royalties that were contingent on future success factors for the licensed programs. The Company used the “most likely amount” method to determine the variable consideration. None of the royalties were included in the transaction price. The Company will re-evaluate the transaction price in each reporting period as uncertain events are resolved or other changes in circumstances occur.

The Company determined the transaction price at inception of the Second Zenas Agreement and allocated it to the performance obligation, delivery of the obexelimab license.

The Company completed delivery of its performance obligations in December 2021. The licenses to obexelimab were transferred to Zenas at inception of the Second Zenas Agreement, and the related research data and documentation was transferred to Zenas in December 2021.

In 2021, the Company purchased a convertible promissory note from Zenas which would automatically convert to equity in a financing transaction.

In November 2022, Zenas completed a financing transaction, pursuant to which a warrant to purchase Zenas equity that was held by the Company was automatically exercised, and a convertible note issued to the Company by Zenas was automatically converted with both converting into shares of Zenas’ preferred stock. After the financing transaction, we continued to record our investment in Zenas at fair value adjusted at each reporting period for impairment or other evidence of change in value. The equity shares in Zenas received from exercise of the warrant and conversion of the notes have an estimated fair value of $34.5 million and $7.7 million, respectively. As a result of the Zenas financing transaction, the estimated fair value of our investment in equity securities increased by $17.9 million. This amount has been recorded in other income.

No revenue was recognized for the year ended December 31, 2022. The Company recognized $14.9 million and $16.1 million of revenue related to the two Zenas Agreements for the years ended December 31, 2021 and 2020, respectively. There is no deferred revenue as of December 31, 2022 related to this agreement.

Revenue Earned

The $164.6 million, $275.1 million, and $122.7 million of revenue recorded for the years ended December 31, 2022, 2021, and 2020, respectively, were earned principally from the following licensees (in millions):


	Year Ended December 31,
	2022		2021		2020
Aimmune	$	—	$	—	$	9.6
Alexion	29.4		22.2		26.2
Astellas	5.0		—		3.5
Genentech	—		2.5		3.5
Gilead	—		—		13.5
Janssen	7.0		113.8		—
MorphoSys	7.8		18.4		39.0
Novartis	—		43.1		—
Omeros	—		—		5.0
Vir	115.4		52.7		0.3
Viridian	—		7.5		6.0
Zenas	—		14.9		16.1
Total	$	164.6	$	275.1	$	122.7

The table below summarizes the disaggregation of revenue recorded for the years ended December 31, 2022, 2021, and 2020 (in millions):


	Year Ended December 31,
	2022		2021		2020
Research collaboration	$	7.0	$	93.0	$	4.5
Milestone	5.5		21.0		50.2
Licensing	—		80.8		50.2
Royalties	152.1		80.3		17.8
Total	$	164.6	$	275.1	$	122.7

Remaining Performance Obligations and Deferred Revenue

The Company’s remaining performance obligation as of December 31, 2022 is conducting research activities pursuant to research plans under the Second Janssen Agreement. As of December 31, 2022 and 2021, we have deferred revenue of $30.3 million and $37.3 million, respectively. All of the deferred revenue was classified as short term as of December 31, 2022 and 2021, respectively, as the Company’s obligations to perform research services are due on demand when requested by Janssen under the Janssen Agreement.

401(k) Plan	12 Months Ended
401(k) Plan	Dec. 31, 2022
Retirement Benefits [Abstract]
401(k) Plan	401(k) PlanWe have a 401(k) plan covering all full-time employees. Employees may make pre-tax contributions up to the maximum allowable by the Internal Revenue Code. Effective January 1, 2018, the Company contributes 100% of the first 1% of participating employees’ contribution and 50% of the next 5% of participating employees’ contribution, for a maximum of 3.5% employer contribution. Effective March 31, 2020, the Company contributes 100% of the first 1% of participating employees’ contribution and 50% of the next 6% of participating employees’ contribution, for a maximum of 4.0% of employer contribution. Participants are immediately vested in their employee contributions; employer contributions are vested over a three-year period with one-third for each year of a participating employee’s service. Employer contributions made for the years ended December 31, 2022, 2021, and 2020 were $1.4 million, $1.1 million, and $0.8 million, respectively.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI https://asc.fasb.org/topic&trid=2235017

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
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-Subparagraph (d)(iii)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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-Section 50
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-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

Summary of Significant Accounting Policies (Polices)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Recent Accounting Pronouncements

Pronouncements Not yet Effective

Revenue Recognition

Deferred Revenue

Deferred RevenueDeferred revenue arises from payments received in advance of the culmination of the earnings process. We have classified deferred revenue for which we stand ready to perform within the next 12 months as a current liability. We recognize deferred revenue as revenue in future periods when the applicable revenue recognition criteria have been met.

Accounts Receivable

Research and Development Expenses

Cash and Cash Equivalents

We consider cash equivalents to be only those investments which are highly liquid, readily convertible to cash and which mature within three months from the date of purchase.

Marketable Debt and Equity Securities

During the years ended December 31, 2022 and 2021, the Company recorded a net gain of $23.4 million and $39.3 million, respectively, in connection with its equity investments.

Concentrations of Risk

Fair Value of Financial Instruments

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

The Company measures the fair value of financial assets using the highest level of inputs that are reasonably available as of the measurement date.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.

Property and Equipment


Computers, software and equipment			3 - 5 years
Furniture and fixtures			5 - 7 years
Leasehold improvements			5 - 7 years or remaining
			lease term, whichever is less

Patents, Licenses, and Other Intangible Assets

Patents, Licenses, and Other Intangible AssetsThe cost of acquiring licenses is capitalized and amortized on the straight-line basis over the shorter of the term of the license or its estimated economic life, ranging from 1 to 18 years. Third-party costs incurred for acquiring patents are capitalized. Capitalized costs are accumulated until the earlier of the period that a patent is issued, or we abandon the patent claims. Cumulative capitalized patent costs are amortized on a straight-line basis from the date of issuance over the shorter of the patent term or the estimated useful economic life of the patent, ranging from 3 to 27 years. Our senior management, with advice from outside patent counsel, assesses three primary criteria to determine if a patent will be capitalized initially: i) technical feasibility, ii) magnitude and scope of new technical function covered by the patent compared to the company’s existing technology and patent portfolio, particularly assessing the value added to our product candidates or licensing business, and iii) legal issues, primarily assessment of patentability and prosecution cost. We review our intellectual property on a regular basis to determine if there are changes in the estimated useful life of issued patents and if any capitalized costs for unissued patents should be abandoned. Capitalized patent costs related to abandoned patent filings are charged off in the period of the decision to abandon.

Long-Lived Assets

Long-Lived AssetsManagement reviews long-lived assets which include fixed assets and amortizable intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets.

Income Taxes

Our policy is to recognize interest and penalties on taxes, if any, as a component of income tax expense.

Stock-Based Compensation

Stock-Based CompensationWe recognize compensation expense using a fair-value-based method for costs related to all share-based payments, including stock options, restricted stock units (RSUs), and shares issued under our Employee Stock Purchase Plan (ESPP). Stock-based compensation cost related to employees and directors is measured at the grant date, based on the fair-value-based measurement of the award using the Black-Scholes method, and is recognized as expense over the requisite service period on a straight-line basis. We account for forfeitures when they occur.

Net Income (Loss) Per Share

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

In 2022 and 2020, we excluded all options and awards from the calculations because we reported net losses in the period, and the inclusion of such shares would have had an antidilutive effect.

For the year ended December 31, 2021, we excluded 1,196,268 shares of options and RSUs from the calculation of diluted net income per common share because the inclusion of such shares would have had an anti-dilutive effect.

Segment Reporting

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [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):


	December 31, 2022
	Total Fair Value		Level 1		Level 2		Level 3

Money Market Funds in Cash and Cash Equivalents	$	40,967	$	40,967	$	—	$	—
Corporate Securities	200,626		—		200,626		—
Government Securities	329,889		—		329,889		—

	$	571,482	$	40,967	$	530,515	$	—


	December 31, 2021
	Total Fair Value		Level 1		Level 2		Level 3

Money Market Funds in Cash and Cash Equivalents	$	123,892	$	123,892	$	—	$	—
Corporate Securities	144,418		—		144,418		—
Government Securities	309,814		—		309,814		—

	$	578,124	$	123,892	$	454,232	$	—

Schedule of useful lives by asset category

Useful lives by asset category are as follows:


Computers, software and equipment			3 - 5 years
Furniture and fixtures			5 - 7 years
Leasehold improvements			5 - 7 years or remaining
			lease term, whichever is less

Schedule of finite-lived intangible assets

The carrying amount and accumulated amortization of patents, licenses, and other intangibles is as follows (in thousands):


	December 31,
	2022		2021
Patents, definite life	$	14,535	$	13,231
Patents, pending issuance	9,328		8,821
Licenses and other amortizable intangible assets	3,908		2,474
Nonamortizable intangible assets (trademarks)	399		399
Total gross carrying amount	28,170		24,925
Accumulated amortization—patents	(7,781)		(6,800)
Accumulated amortization—licenses and other	(1,889)		(1,632)
Total intangible assets, net	$	18,500	$	16,493

Schedule of indefinite-lived intangible assets

The carrying amount and accumulated amortization of patents, licenses, and other intangibles is as follows (in thousands):


	December 31,
	2022		2021
Patents, definite life	$	14,535	$	13,231
Patents, pending issuance	9,328		8,821
Licenses and other amortizable intangible assets	3,908		2,474
Nonamortizable intangible assets (trademarks)	399		399
Total gross carrying amount	28,170		24,925
Accumulated amortization—patents	(7,781)		(6,800)
Accumulated amortization—licenses and other	(1,889)		(1,632)
Total intangible assets, net	$	18,500	$	16,493

Future amortization expense for patents, licenses, and other intangible assets

Future amortization expense for patent, licenses, and other intangible assets recorded as of December 31, 2022, and for which amortization has commenced, is as follows:


	Year ended December 31,
	(in thousands)
2023	$	1,165
2024	1,123
2025	1,110
2026	1,097
2027	1,096
Thereafter	3,181
Total	$	8,772

Schedule of basic and diluted net income (loss) per common share

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

In 2022 and 2020, we excluded all options and awards from the calculations because we reported net losses in the period, and the inclusion of such shares would have had an antidilutive effect.


	Year Ended December 31,
	2022		2021		2020
	(in thousands, except share and per share data)
Basic
Numerator:
Net income (loss) attributable to common stockholders for basic net income (loss) per share	$	(55,181)	$	82,631	$	(69,333)
Denominator:
Weighted-average common shares outstanding	59,652,461		58,379,641		57,212,737
Basic net income (loss) per common share	$	(0.93)	$	1.42	$	(1.21)

Diluted
Numerator:
Net income (loss) attributable to common stockholders for diluted net income (loss) per share	$	(55,181)	$	82,631	$	(69,333)
Denominator:
Weighted average number of common shares outstanding used in computing basic net income (loss) per common share	59,652,461		58,379,641		57,212,737
Dilutive effect of employee stock options, RSUs, and ESPP	—		2,115,814		—
Weighted-average number of common shares outstanding used in computing diluted net income (loss) per common share	59,652,461		60,495,455		57,212,737
Diluted net income (loss) per common share	$	(0.93)	$	1.37	$	(1.21)

Marketable Debt and Equity Securities (Tables)

12 Months Ended

Dec. 31, 2022

Marketable Securities [Abstract]

Schedule of marketable securities

The Company’s marketable debt securities held as of December 31, 2022 and 2021 are summarized below:


	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


	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
(in thousands)
Money Market Funds	$	123,892	$	—	$	—	$	123,892
Corporate Securities	144,584		—		(166)		144,418
Government Securities	311,148		1		(1,335)		309,814
	$	579,624	$	1	$	(1,501)	$	578,124

Reported as
Cash and cash equivalents							$	123,892
Marketable securities							454,232
Total investments							$	578,124

Schedule of maturities of marketable securities

The maturities of the Company’s marketable debt securities as of December 31, 2022 are as follows:


	Amortized Cost		Estimated Fair Value
(in thousands)
Mature in one year or less	$	533,626	$	526,689
Mature within two years	3,831		3,826
	$	537,457	$	530,515

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value

The unrealized losses on available-for-sale investments and their related fair values as of December 31, 2022 and 2021 are as follows:


	December 31, 2022
	Less than 12 months				12 months or greater
	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)


	December 31, 2021
	Less than 12 months				12 months or greater
	Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	50,337	$	(51)	$	45,872	$	(115)
Government Securities	39,909		(54)		254,593		(1,281)
	$	90,246	$	(105)	$	300,465	$	(1,396)

Schedule of equity securities with readily determinable fair value

Equity securities with a readily determinable fair value and their fair values (in thousands) as of December 31, 2022 and 2021 are as follows:


	Fair Value December 31, 2022		Fair Value December 31, 2021
Astria Common Stock	$	9,529	$	3,449
INmune Common Stock	11,954		19,233
Viridian Common Stock	20,948		14,178
	$	42,431	$	36,860

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 December 31, 2022 and 2021 are as follows:


	Carrying Value December 31, 2022		Carrying Value December 31, 2021
Astria Preferred Stock	$	174	$	312
Zenas Preferred Stock	54,209		30,950
	$	54,383	$	31,262

Schedule of net gains and losses

Unrealized gains and losses recognized on equity securities (in thousands) during the year ended December 31, 2022 and 2021 consist of the following:


	Year Ended December 31,
	2022		2021

Net gains recognized on equity securities	$	23,434	$	39,289
Less: net gains recognized on equity securities redeemed	—		18,301
Unrealized gain (losses) recognized on equity securities	$	23,434	$	20,988

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Schedule of property and equipment

Property and equipment consist of the following:


	December 31,
	2022		2021
	(in thousands)
Computers, software and equipment	$	45,159	$	41,955
Furniture and fixtures	539		539
Leasehold and tenant improvements	41,774		8,574
Total gross carrying amount	87,472		51,068
Less accumulated depreciation and amortization	(28,289)		(22,828)
Total property and equipment, net	$	59,183	$	28,240

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Reconciliation of the federal statutory income tax rate to our effective income tax rate

A reconciliation of the federal statutory income tax to our effective income tax is as follows (in thousands):


	Year Ended December 31,
	2022		2021		2020
Federal statutory income tax	$	(11,447)	$	17,352	$	(14,559)
State and local income taxes	(615)		783		(4,659)
Research and development credit	(9,366)		(10,492)		(9,669)
Stock-based compensation	3,384		2,424		529
Foreign-derived intangible income	(1,449)		—		—
Other	(74)		95		56
Change in state rate	44		2,599		—
Net change in valuation allowance	20,196		(12,761)		28,302
Income tax provision	$	673	$	—	$	—

Schedule of tax effect of temporary differences that give rise to a significant portion of the deferred tax assets and liabilities

The tax effect of temporary differences that give rise to a significant portion of the deferred tax assets and liabilities at December 31, 2022 and 2021 is presented below (in thousands):


	December 31,
	2022		2021
Deferred income tax assets
Net operating loss carryforwards	$	32,898	$	46,629
Research credits	54,825		48,128
Unrealized loss on securities	1,573		327
Capitalized lease assets	5,564		489
Accrued compensation	14,484		9,207
Capitalized research and development costs	21,338		—
Gross deferred income tax assets	130,682		104,780
Valuation allowance	(115,010)		(93,580)
Net deferred income tax assets	15,672		11,200
Deferred income tax liabilities
Patent costs	(2,885)		(3,416)
Deferred revenue	3,225		(3,508)
Licensing costs	(124)		(151)
Capitalized legal costs	(9)		(13)
Depreciation	(6,532)		(288)
Unrealized gain on securities	(9,347)		(3,824)
Gross deferred income tax liabilities	(15,672)		(11,200)
Net deferred income tax asset	$	—	$	—

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

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 was as follows:


	Year Ended December 31,
(in thousands)	2022		2021		2020
General and administrative	$	17,281	$	12,813	$	10,769
Research and development	31,632		24,162		20,850
	$	48,913	$	36,975	$	31,619


	Year Ended December 31,
(in thousands)	2022		2021		2020
Stock options	$	29,758	$	27,909	$	26,045
ESPP	1,174		992		804
RSUs	17,981		8,074		4,770
	$	48,913	$	36,975	$	31,619

Schedule of stock options outstanding

Information with respect to stock options outstanding is as follows:


	December 31,
	2022		2021		2020
Exercisable options	6,679,948		5,576,430		4,668,179
Weighted average exercise price per share of exercisable options	$	26.99	$	24.15	$	21.75
Weighted average grant date fair value per share of options granted during the year	$	15.45	$	21.65	$	16.96
Options available for future grants	3,622,319		3,597,371		3,346,092
Weighted average remaining contractual life	6.30		6.65		7.00

Summary of stock option activity

The following table summarizes stock option activity for the years ended December 31, 2022 and 2021:


	Number of Shares	Weighted- Average Exercise Price (Per Share)(1)		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)(2)
Balances at December 31, 2019	7,174,319	$	24.03	7.32	$	79,116
Options granted	1,679,324	33.08
Options forfeited	(243,384)	32.93
Options exercised(3)	(858,470)	19.36
Balances at December 31, 2020	7,751,789	26.23		7.00	$	134,941
Options granted	1,827,234	41.22
Options forfeited	(382,454)	36.15
Options exercised(3)	(520,240)	23.61
Balances at December 31, 2021	8,676,329	29.11		6.65	$	100,057
Options granted	2,135,233	29.45
Options forfeited	(533,435)	34.09
Options exercised(3)	(195,485)	18.46
Balances at December 31, 2022	10,082,642	$	29.12	6.30	$	27,141
As of December 31, 2022
Options vested and expected to vest	10,082,642	$	29.12	6.30	$	27,141
Exercisable	6,679,948	$	26.99	5.10	$	26,979

______________________________

(1)The weighted average exercise price per share is determined using exercise price per share for stock options.

(3)The total intrinsic value of stock options exercised was $1.6 million, $9.2 million, and $16.3 million for the years ended December 31, 2022, 2021 and 2020 respectively.

Schedule of weighted average assumptions used for estimation of fair value of stock options

The fair value of employee stock options was estimated using the following weighted average assumptions for the years ended December 31, 2022, 2021 and 2020:


	Options
	2022	2021	2020
Common stock fair value per share	$19.74 - 38.08	$30.65- 49.47	$20.69 - 45.91
Expected volatility	51.51% - 54.36%	53.91% - 56.82%	52.93% - 58.95%
Risk-free interest rate	1.57% - 4.34%	0.47% - 1.33%	0.29% - 1.71%
Expected dividend yield	—	—	—
Expected term (in years)	6.00 - 7.65	6.00 - 7.65	5.23 - 7.65

Schedule of weighted average assumptions used for estimation of fair value of ESPP

The fair value of employee stock options was estimated using the following weighted average assumptions for the years ended December 31, 2022, 2021 and 2020:


	ESPP
	2022	2021	2020
Expected term (years)	0.5 - 2.0	0.5 - 2.0	0.5 - 2.0
Expected volatility	43.19% - 55.72%	46.08% - 66.37%	50.77% - 66.37%
Risk-free interest rate	0.13% - 4.72%	0.04% - 1.65%	0.09% - 1.65%
Expected dividend yield	—	—	—

Summary of restricted stock unit activity

The following table summarizes RSU activity for the years ended December 31, 2022:


	Number of Shares	Weighted- Average Grant Date Fair Value (Per Unit)
Unvested at December 31, 2019	90,006	$	34.66
Granted	348,288	32.51
Vested	(62,355)	32.61
Forfeited	(17,114)	32.33
Unvested at December 31, 2020	358,825	$	33.04
Granted	670,700	39.11
Vested	(151,555)	32.76
Forfeited	(51,822)	36.68
Unvested at December 31, 2021	826,148	$	37.79
Granted	875,330	29.45
Vested	(341,073)	37.37
Forfeited	(127,854)	33.66
Unvested at December 31, 2022	1,232,551	$	32.41

Leases (Tables)

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Schedule of operating lease liabilities maturities

The following table reconciles the undiscounted cash flows for the operating leases at December 31, 2022 to the operating lease liabilities recorded on the balance sheet (in thousands):


Years ending December 31,
2023	$	6,558
2024	6,072
2025	7,392
2026	8,589
2027	8,829
Thereafter	75,512
Total undiscounted lease payments	112,952
Less: Tenant allowance	(5,459)
Less: Imputed interest	(47,859)
Present value of lease payments	$	59,634

Lease liabilities - short-term	$	4,708
Lease liabilities - long-term	54,926
Total lease liabilities	$	59,634

Summary of lease costs and cash disclosures

The following table summarizes lease costs, cash, and other disclosures for the years ended December 31, 2022, 2021, and 2020 (in thousands):


	Year Ended December 31,
	2022			2021			2020

Operating lease cost	$	6,588		$	4,342		$	2,503
Variable lease cost	506			58			150
Total lease costs	$	7,094		$	4,400		$	2,653
Cash paid for amounts included in
the measurement of lease liabilities	$	2,869		$	2,773		$	2,233
Weighted-average remaining lease term
—operating leases (in years)	12.0			12.3			7.4
Weighted-average discount rate
—operating leases	8.9		%	5.8		%	5.5		%

Collaboration and Licensing Agreements (Tables)

12 Months Ended

Dec. 31, 2022

Collaboration and Licensing Agreements

Schedule of revenue by licensees


	Year Ended December 31,
	2022		2021		2020
Aimmune	$	—	$	—	$	9.6
Alexion	29.4		22.2		26.2
Astellas	5.0		—		3.5
Genentech	—		2.5		3.5
Gilead	—		—		13.5
Janssen	7.0		113.8		—
MorphoSys	7.8		18.4		39.0
Novartis	—		43.1		—
Omeros	—		—		5.0
Vir	115.4		52.7		0.3
Viridian	—		7.5		6.0
Zenas	—		14.9		16.1
Total	$	164.6	$	275.1	$	122.7

Schedule of disaggregation of revenue

The table below summarizes the disaggregation of revenue recorded for the years ended December 31, 2022, 2021, and 2020 (in millions):


	Year Ended December 31,
	2022		2021		2020
Research collaboration	$	7.0	$	93.0	$	4.5
Milestone	5.5		21.0		50.2
Licensing	—		80.8		50.2
Royalties	152.1		80.3		17.8
Total	$	164.6	$	275.1	$	122.7

Summary of Significant Accounting Policies - Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Deferred revenue	$ 30,320	$ 37,294

Summary of Significant Accounting Policies - Accounts Receivable (Details)	12 Months Ended
	Dec. 31, 2022
Minimum
Accounts Receivable Collection Period [Line Items]
Collection period	30 days
Maximum
Accounts Receivable Collection Period [Line Items]
Collection period	60 days

Summary of Significant Accounting Policies - Marketable Debt and Equity Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Impairment loss or recoveries	$ 0	$ 0
Accrued interest	1,300,000	800,000
Unrealized loss on marketable debt securities	5,400,000	1,600,000
Equity securities impairment	100,000	800,000
Net gains recognized on equity securities	$ 23,434,000	$ 39,289,000	$ 105,000

Summary of Significant Accounting Policies - Concentrations of Risk (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Concentrations of risk
Amounts on deposit in excess of federally insured limits approximately	$ 53.6	$ 143.2
Accounts Receivable \| Customer Concentration Risk \| Major Customers
Concentrations of risk
Concentration risk percentage	91.00%	84.00%
Accounts Payable \| Supplier Concentration Risk \| Major Vendors
Concentrations of risk
Concentration risk percentage	45.00%
Accounts Payable \| Supplier Concentration Risk \| Top Vendor
Concentrations of risk
Concentration risk percentage	64.00%	64.00%

Summary of Significant Accounting Policies - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value of Financial Instruments
Money Market Funds in Cash and Cash Equivalents	$ 53,942	$ 143,480
Marketable securities	530,515
Money Market Funds in Cash and Cash Equivalents
Fair Value of Financial Instruments
Money Market Funds in Cash and Cash Equivalents	40,967	123,892
Corporate Securities
Fair Value of Financial Instruments
Marketable securities	200,626	144,418
Government Securities
Fair Value of Financial Instruments
Marketable securities	329,889	309,814
Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	571,482	578,124
Fair Value, Recurring \| Money Market Funds in Cash and Cash Equivalents
Fair Value of Financial Instruments
Money Market Funds in Cash and Cash Equivalents	40,967	123,892
Fair Value, Recurring \| Corporate Securities
Fair Value of Financial Instruments
Marketable securities	200,626	144,418
Fair Value, Recurring \| Government Securities
Fair Value of Financial Instruments
Marketable securities	329,889	309,814
Level 1 \| Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	40,967	123,892
Level 1 \| Fair Value, Recurring \| Money Market Funds in Cash and Cash Equivalents
Fair Value of Financial Instruments
Money Market Funds in Cash and Cash Equivalents	40,967	123,892
Level 1 \| Fair Value, Recurring \| Corporate Securities
Fair Value of Financial Instruments
Marketable securities	0	0
Level 1 \| Fair Value, Recurring \| Government Securities
Fair Value of Financial Instruments
Marketable securities	0	0
Level 2 \| Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	530,515	454,232
Level 2 \| Fair Value, Recurring \| Money Market Funds in Cash and Cash Equivalents
Fair Value of Financial Instruments
Money Market Funds in Cash and Cash Equivalents	0	0
Level 2 \| Fair Value, Recurring \| Corporate Securities
Fair Value of Financial Instruments
Marketable securities	200,626	144,418
Level 2 \| Fair Value, Recurring \| Government Securities
Fair Value of Financial Instruments
Marketable securities	329,889	309,814
Level 3 \| Fair Value, Recurring
Fair Value of Financial Instruments
Total Fair Value	0	0
Level 3 \| Fair Value, Recurring \| Money Market Funds in Cash and Cash Equivalents
Fair Value of Financial Instruments
Money Market Funds in Cash and Cash Equivalents	0	0
Level 3 \| Fair Value, Recurring \| Corporate Securities
Fair Value of Financial Instruments
Marketable securities	0	0
Level 3 \| Fair Value, Recurring \| Government Securities
Fair Value of Financial Instruments
Marketable securities	$ 0	$ 0

Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2022
Computers, software and equipment \| Minimum
Property and Equipment
Estimated useful lives of the assets	3 years
Computers, software and equipment \| Maximum
Property and Equipment
Estimated useful lives of the assets	5 years
Furniture and fixtures \| Minimum
Property and Equipment
Estimated useful lives of the assets	5 years
Furniture and fixtures \| Maximum
Property and Equipment
Estimated useful lives of the assets	7 years
Leasehold improvements \| Minimum
Property and Equipment
Estimated useful lives of the assets	5 years
Leasehold improvements \| Maximum
Property and Equipment
Estimated useful lives of the assets	7 years

Summary of Significant Accounting Policies - Patents, Licenses, and Other Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) criteria	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Patents, licenses, and other intangible assets
Number of primary criteria to determine capitalization of patent \| criteria	3
Abandonment of capitalized intangible assets	$ 1,510	$ 934	$ 535
Total gross carrying amount	28,170	24,925
Total intangible assets, net	18,500	16,493
Amortization expense for patents, licenses, and other intangible assets	1,400	1,200	$ 1,100
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2023	1,165
2024	1,123
2025	1,110
2026	1,097
2027	1,096
Thereafter	3,181
Total	8,772
Nonamortizable intangible assets (trademarks)
Patents, licenses, and other intangible assets
Nonamortizable intangible assets (trademarks)	$ 399	399
Licensing Agreements \| Minimum
Patents, licenses, and other intangible assets
Estimated economic life	1 year
Licensing Agreements \| Maximum
Patents, licenses, and other intangible assets
Estimated economic life	18 years
Patents
Patents, licenses, and other intangible assets
Accumulated amortization	$ (7,781)	(6,800)
Patents \| Minimum
Patents, licenses, and other intangible assets
Estimated economic life	3 years
Patents \| Maximum
Patents, licenses, and other intangible assets
Estimated economic life	27 years
Patents, definite life
Patents, licenses, and other intangible assets
Amortizable intangible assets	$ 14,535	13,231
Patents, pending issuance
Patents, licenses, and other intangible assets
Amortizable intangible assets	9,328	8,821
Licenses and other amortizable intangible assets
Patents, licenses, and other intangible assets
Amortizable intangible assets	3,908	2,474
Accumulated amortization	$ (1,889)	$ (1,632)

Summary of Significant Accounting Policies - Income Taxes (Details) $ in Millions	Dec. 31, 2020 USD ($)
Domestic Tax Authority
Income Taxes [Line Items]
Income tax refund	$ 0.8

Summary of Significant Accounting Policies - Stock-Based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock-Based Compensation
Stock-based compensation	$ 48.9	$ 37.0	$ 31.6

Summary of Significant Accounting Policies - Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net income (loss) attributable to common stockholders for basic net income (loss) per share	$ (55,181)	$ 82,631	$ (69,333)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	59,652,461	58,379,641	57,212,737
Net income (loss) per common share, basic (in dollars per share)	$ (0.93)	$ 1.42	$ (1.21)
Numerator:
Net income (loss) attributable to common stockholders for diluted net income (loss) per share	$ (55,181)	$ 82,631	$ (69,333)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	59,652,461	58,379,641	57,212,737
Dilutive effect of employee stock options and ESPP (in shares)	0	2,115,814	0
Weighted-average common shares outstanding, diluted (in shares)	59,652,461	60,495,455	57,212,737
Net income (loss) per common share, diluted (in dollars per share)	$ (0.93)	$ 1.37	$ (1.21)
Securities excluded in calculation of EPS (in shares)		1,196,268

Summary of Significant Accounting Policies - Segments (Details)	12 Months Ended
	Dec. 31, 2022 segment
Segment Reporting [Abstract]
Number of operating segments	1

Marketable Debt and Equity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities
Money Market Funds in Cash and Cash Equivalents	$ 53,942	$ 143,480
Amortized Cost	537,457
Amortized Cost	578,424	579,624
Gross Unrealized Gains	3	1
Gross Unrealized Losses	(6,945)	(1,501)
Marketable securities	530,515
Total investments	571,482	578,124
Money Market Funds in Cash and Cash Equivalents
Schedule of Available-for-sale Securities
Money Market Funds in Cash and Cash Equivalents	40,967	123,892
Corporate Securities
Schedule of Available-for-sale Securities
Amortized Cost	201,752	144,584
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,126)	(166)
Marketable securities	200,626	144,418
Government Securities
Schedule of Available-for-sale Securities
Amortized Cost	335,705	311,148
Gross Unrealized Gains	3	1
Gross Unrealized Losses	(5,819)	(1,335)
Marketable securities	329,889	309,814
Cash and cash equivalents
Schedule of Available-for-sale Securities
Money Market Funds in Cash and Cash Equivalents	40,967	123,892
Marketable securities
Schedule of Available-for-sale Securities
Marketable securities	$ 530,515	$ 454,232

Marketable Debt and Equity Securities - Maturities (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Amortized Cost
Mature in one year or less	$ 533,626
Mature within two years	3,831
Amortized Cost	537,457
Estimated Fair Value
Mature in one year or less	526,689
Mature within two years	3,826
Estimated Fair Value	$ 530,515

Marketable Debt and Equity Securities - Unrealized Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities
Fair value, less than 12 months	$ 457,591	$ 90,246
Unrealized losses, less than 12 months	(6,940)	(105)
Fair value, 12 months or greater	3,826	300,465
Unrealized losses, 12 months or greater	(5)	(1,396)
Corporate Securities
Schedule of Available-for-sale Securities
Fair value, less than 12 months	132,658	50,337
Unrealized losses, less than 12 months	(1,121)	(51)
Fair value, 12 months or greater	3,826	45,872
Unrealized losses, 12 months or greater	(5)	(115)
Government Securities
Schedule of Available-for-sale Securities
Fair value, less than 12 months	324,933	39,909
Unrealized losses, less than 12 months	(5,819)	(54)
Fair value, 12 months or greater	0	254,593
Unrealized losses, 12 months or greater	$ 0	$ (1,281)

Marketable Debt and Equity Securities - Equity Securities with Readily Determinable Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Equity Securities
Equity securities with readily determinable fair value	$ 42,431	$ 36,860
Common Stock
Equity Securities
Equity securities with readily determinable fair value	42,431	36,860
Astria/Catabasis \| Common Stock
Equity Securities
Equity securities with readily determinable fair value	9,529	3,449
INmune \| Common Stock
Equity Securities
Equity securities with readily determinable fair value	11,954	19,233
Viridian \| Common Stock
Equity Securities
Equity securities with readily determinable fair value	$ 20,948	$ 14,178

Marketable Debt and Equity Securities - Equity Securities without Readily Determinable Fair Value (Details) - Preferred Stock - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Equity securities without readily determinable fair value
Equity securities without readily determinable fair value	$ 54,383	$ 31,262
Astria/Catabasis
Equity securities without readily determinable fair value
Equity securities without readily determinable fair value	174	312
Zenas
Equity securities without readily determinable fair value
Equity securities without readily determinable fair value	$ 54,209	$ 30,950

Marketable Debt and Equity Securities - Equity Securities Transactions (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Nov. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity Securities
Equity securities impairment				$ 100	$ 800
Net gains recognized on equity securities				23,434	39,289	$ 105
Astria/Catabasis \| Preferred Stock
Equity Securities
Equity securities impairment				100	$ 800
Zenas \| Warrant \| Notes Receivable
Equity Securities
Unrealized gain on warrant exchange and conversion of promissory note				$ 21,900
License Agreement \| INmune
Equity Securities
Cash consideration on sale of option		$ 15,000
License Agreement \| INmune \| Common Stock
Equity Securities
Cash consideration on sale of option		$ 15,000
Number of shares acquired	108,000
Purchase amount of share options or equity in noncash transaction	$ 800
Net gains recognized on equity securities	$ 900
License Agreement \| Zenas
Equity Securities
Purchase amount of share options or equity in noncash transaction			$ 16,100

Marketable Debt and Equity Securities - Net Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities [Abstract]
Net gains recognized on equity securities	$ 23,434	$ 39,289	$ 105
Less: net gains recognized on equity securities redeemed	0	18,301
Unrealized gain (losses) recognized on equity securities	$ 23,434	$ 20,988	$ 105

Sale of Additional Common Stock (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Oct. 01, 2021 USD ($) d $ / shares shares	Dec. 31, 2021 USD ($) shares
Proceeds from sale of common stock		$ 28,920
Second Collaboration And License Agreement \| Common Stock \| Johnson & Johnson Innovation, JJDC, Inc.
Proceeds from sale of common stock	$ 25,000
Number of trading days \| d	30
Weighted average price (in dollars per share) \| $ / shares	$ 33.4197
Total equity shares (in shares) \| shares	748,062
Common Stock
Proceeds from sale of common stock		$ 7
Total equity shares (in shares) \| shares		748,062

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property and Equipment
Total gross carrying amount	$ 87,472	$ 51,068
Less accumulated depreciation and amortization	(28,289)	(22,828)
Total property and equipment, net	59,183	28,240
Depreciation expense	7,400	6,300	$ 4,700
Computers, software and equipment
Property and Equipment
Total gross carrying amount	45,159	41,955
Furniture and fixtures
Property and Equipment
Total gross carrying amount	539	539
Leaseholds and Leasehold Improvements [Member]
Property and Equipment
Total gross carrying amount	$ 41,774	$ 8,574

Income Taxes - Reconciliation to effective income tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of federal statutory income tax to effective income tax
Federal statutory income tax	$ (11,447)	$ 17,352	$ (14,559)
State and local income taxes	(615)	783	(4,659)
Research and development credit	(9,366)	(10,492)	(9,669)
Stock-based compensation	3,384	2,424	529
Foreign-derived intangible income	(1,449)	0	0
Other	(74)	95	56
Change in state rate	44	2,599	0
Net change in valuation allowance	20,196	(12,761)	28,302
Income tax provision	$ 673	$ 0	$ 0

Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred income tax assets
Net operating loss carryforwards	$ 32,898	$ 46,629
Research credits	54,825	48,128
Unrealized loss on securities	1,573	327
Capitalized lease assets	5,564	489
Accrued compensation	14,484	9,207
Capitalized research and development costs	21,338	0
Gross deferred income tax assets	130,682	104,780
Valuation allowance	(115,010)	(93,580)
Net deferred income tax assets	15,672	11,200
Deferred income tax liabilities
Patent costs	(2,885)	(3,416)
Deferred revenue	3,225	(3,508)
Licensing costs	(124)	(151)
Capitalized legal costs	(9)	(13)
Depreciation	(6,532)	(288)
Unrealized gain on securities	(9,347)	(3,824)
Gross deferred income tax liabilities	(15,672)	(11,200)
Net deferred income tax asset	$ 0	$ 0

Income Taxes - TCJA and net operating loss carryforwards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2020
Income Taxes [Line Items]
Increase (decrease) in deferred tax asset valuation allowance	$ 21.4
Domestic Tax Authority
Income Taxes [Line Items]
Income tax refund		$ 0.8
Cumulative net operating loss carryforwards	102.4
Tax credit carryforwards	38.7
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	162.1
Tax credit carryforwards	20.4
Years Prior to 2018 \| Domestic Tax Authority
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	59.0
Years After 2018 \| Domestic Tax Authority
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	$ 43.4

Stock-Based Compensation - Plan Details (Details)		12 Months Ended			108 Months Ended
Stock-Based Compensation - Plan Details (Details)	Jan. 01, 2022 shares	Dec. 31, 2022 period shares	Dec. 31, 2021 shares	Dec. 31, 2020 shares	Dec. 31, 2022 period shares
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance (in shares)		3,622,319	3,597,371	3,346,092	3,622,319
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance (in shares)		539,392			539,392
Increase in shares of common stock available for issuance (in shares)	593,555
Awards issued under the plan (in shares)					635,449
Initial term of plan		2 years
Number of six month purchase periods \| period		4			4
Purchase period		6 months
Second term of plan		2 years
ESPP \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of compensation that employees may withhold to purchase stock at a discount		1.00%			1.00%
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%
Percentage of compensation that employees may withhold to purchase stock at a discount		15.00%			15.00%
Purchase price as percentage of stock price at the initial offering date		85.00%
Purchase price as percentage of stock price at the purchase date		85.00%
Annual increase in shares of common stock available for issuance		621,814
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Restricted stock granted (in shares)		875,330	670,700	348,288
The 2010 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance (in shares)		0			0
The 2013 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total number of shares of common stock available for issuance (in shares)		14,792,799			14,792,799
Annual percentage increase in shares of common stock available for issuance		4.00%
Increase in shares of common stock available for issuance (in shares)	2,374,222
Awards issued under the plan (in shares)					14,535,306
The 2013 Plan \| RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Restricted stock granted (in shares)					1,999,817
The 2013 Plan \| RSUs \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period		2 years
The 2013 Plan \| RSUs \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period		3 years

Stock-Based Compensation - Employee Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	$ 48,913	$ 36,975	$ 31,619
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	29,758	27,909	26,045
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	1,174	992	804
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	17,981	8,074	4,770
General and administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	17,281	12,813	10,769
Research and development
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total employee, director and non-employee stock-based compensation expense	$ 31,632	$ 24,162	$ 20,850

Stock-Based Compensation - Stock Options Outstanding (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Aggregate Intrinsic Value (in thousands)
Exercisable options (in shares)	6,679,948	5,576,430	4,668,179
Weighted-average exercise price per share of exercisable options (in dollars per share)	$ 26.99	$ 24.15	$ 21.75
Weighted average grant date fair value per share of options granted during the year (in dollars per share)	$ 15.45	$ 21.65	$ 16.96
Total number of shares of common stock available for issuance (in shares)	3,622,319	3,597,371	3,346,092
Weighted-average remaining contractual life	6 years 3 months 18 days	6 years 7 months 24 days	7 years	7 years 3 months 25 days

Stock-Based Compensation - Stock Option Activity (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of Shares
Balance at the beginning of the period (in shares)	8,676,329	7,751,789	7,174,319
Options granted (in shares)	2,135,233	1,827,234	1,679,324
Options forfeited (in shares)	(533,435)	(382,454)	(243,384)
Options exercised (in shares)	(195,485)	(520,240)	(858,470)
Balance at the end of the period (in shares)	10,082,642	8,676,329	7,751,789	7,174,319
Options vested and expected to vest (in shares)	10,082,642
Exercisable (in shares)	6,679,948	5,576,430	4,668,179
Weighted-Average Exercise Price (Per Share)
Balance at the beginning of the period (in dollars per share)	$ 29.11	$ 26.23	$ 24.03
Options granted (in dollars per share)	29.45	41.22	33.08
Options forfeited (in dollars per share)	34.09	36.15	32.93
Options exercised (in dollars per share)	18.46	23.61	19.36
Balance at the end of the period (in dollars per share)	29.12	29.11	26.23	$ 24.03
Options vested and expected to vest (in dollars per share)	29.12
Exercisable (in dollars per share)	$ 26.99	$ 24.15	$ 21.75
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-average remaining contractual term, balance outstanding	6 years 3 months 18 days	6 years 7 months 24 days	7 years	7 years 3 months 25 days
Weighted-average remaining contractual term, options vested and expected to vest	6 years 3 months 18 days
Weighted-average remaining contractual term, exercisable	5 years 1 month 6 days
Aggregate intrinsic value, balance outstanding	$ 27,141	$ 100,057	$ 134,941	$ 79,116
Aggregate intrinsic value, options vested and expected to vest	27,141
Aggregate intrinsic value, exercisable	26,979
Intrinsic value of options exercised	$ 1,600	$ 9,200	$ 16,300

Stock-Based Compensation - FV of Employee Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Weighted average assumptions for estimated fair value of employee stock options
Expected dividend yield	0.00%	0.00%	0.00%
Stock options
Weighted average assumptions for estimated fair value of employee stock options
Common stock fair value per share minimum (in dollars per share)	$ 19.74	$ 30.65	$ 20.69
Common stock fair value per share maximum (in dollars per share)	$ 38.08	$ 49.47	$ 45.91
Expected volatility, low end of range (as a percent)	51.51%	53.91%	52.93%
Expected volatility, high end of range (as a percent)	54.36%	56.82%	58.95%
Risk-free interest rate, low end of range (as a percent)	1.57%	0.47%	0.29%
Risk-free interest rate, high end of range (as a percent)	4.34%	1.33%	1.71%
Stock options \| Minimum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (in years)	6 years	6 years	5 years 2 months 23 days
Stock options \| Maximum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (in years)	7 years 7 months 24 days	7 years 7 months 24 days	7 years 7 months 24 days
ESPP
Weighted average assumptions for estimated fair value of employee stock options
Expected volatility, low end of range (as a percent)	43.19%	46.08%	50.77%
Expected volatility, high end of range (as a percent)	55.72%	66.37%	66.37%
Risk-free interest rate, low end of range (as a percent)	0.13%	0.04%	0.09%
Risk-free interest rate, high end of range (as a percent)	4.72%	1.65%	1.65%
ESPP \| Minimum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (in years)	6 months	6 months	6 months
ESPP \| Maximum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (in years)	2 years	2 years	2 years

Stock-Based Compensation - Restricted Stock Units (Details) - RSUs - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Number of Shares
Beginning balance (in shares)	826,148	358,825	90,006
Granted (in shares)	875,330	670,700	348,288
Vested (in shares)	(341,073)	(151,555)	(62,355)
Forfeited (in shares)	(127,854)	(51,822)	(17,114)
Ending balance (in shares)	1,232,551	826,148	358,825
Weighted- Average Grant Date Fair Value (Per Unit)
Weighted-average grant date fair value, beginning balance (in dollars per share)	$ 37.79	$ 33.04	$ 34.66
Weighted-average grant date fair value, granted (in dollars per share)	29.45	39.11	32.51
Weighted-average grant date fair value, vested (in dollars per share)	37.37	32.76	32.61
Weighted-average grant date fair value, forfeited (in dollars per share)	33.66	36.68	32.33
Weighted -average grant date fair value, ending balance (in dollars per share)	$ 32.41	$ 37.79	$ 33.04

Stock-Based Compensation - Unamortized Compensation Expense for Unvested Stock Options (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized compensation expense related to unvested stock options and ESPP	$ 52.6	$ 54.5
Period to recognize unamortized compensation expense	2 years 5 months 4 days
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unamortized compensation expense related to unvested stock options and ESPP	$ 1.2	2.3
Period to recognize unamortized compensation expense	11 months 8 days
RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Period to recognize unamortized compensation expense	1 year 10 months 24 days
Unamortized compensation expense related to unvested restricted stock units	$ 28.3	$ 24.8

Leases - Agreements (Details)		1 Months Ended		12 Months Ended
Leases - Agreements (Details)	Jul. 14, 2021 USD ($) ft² uSDollarPerSquareFoot	Aug. 31, 2022 USD ($) uSDollarPerSquareFoot	Jun. 30, 2021 ft² phase	Dec. 31, 2022 USD ($) lease	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 01, 2025 USD ($) ft²
Lessee, Lease, Description [Line Items]
Addition of right-of-use asset				$ 6,155,000	$ 24,047,000	$ 3,127,000
Monrovia, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Number of leases \| lease				2
Option to extend				true
Renewal term				5 years
Addition of right-of-use asset				$ 300,000
Monrovia, CA - office and laboratory space with additional space
Lessee, Lease, Description [Line Items]
Addition of right-of-use asset				$ 300,000
Lease term			18 months
San Diego, CA - office space
Lessee, Lease, Description [Line Items]
Option to extend				true
Renewal term				5 years
Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Addition of right-of-use asset				$ 15,300,000	$ 29,700,000
Area of property \| ft²	83,083		129,543
Lease term	13 years
Phases of lease term \| phase			2
Improvement allowance	$ 17,000,000	$ 22,000,000
Initial base monthly rent	$ 386,336	$ 416,246
Rent expense per square foot \| uSDollarPerSquareFoot	4.65	5.01
Rent increase (as a percentage)	3.00%
Increase to tenant allowance		$ 5,000,000
Forecast \| Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Area of property \| ft²							46,460
Improvement allowance							$ 3,300,000

Leases - Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
2023	$ 6,558
2024	6,072
2025	7,392
2026	8,589
2027	8,829
Thereafter	75,512
Total undiscounted lease payments	112,952
Less: Tenant allowance	(5,459)
Less: Imputed interest	(47,859)
Present value of lease payments	59,634
Lease liabilities - short-term	4,708	$ 0
Lease liabilities - long-term	$ 54,926	$ 33,969

Leases - Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Lease Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease cost	$ 6,588	$ 4,342	$ 2,503
Variable lease cost	506	58	150
Total lease costs	7,094	4,400	2,653
Cash paid for amounts included in the measurement of lease liabilities	$ 2,869	$ 2,773	$ 2,233
Weighted-average remaining lease term	12 years	12 years 3 months 18 days	7 years 4 months 24 days
Weighted-average discount rate	8.90%	5.80%	5.50%

Collaboration and Licensing Agreements - Narrative (Details)		1 Months Ended										3 Months Ended			12 Months Ended
	Oct. 01, 2021 USD ($) d candidate agreement $ / shares shares	Dec. 31, 2021 USD ($) candidate	Nov. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Nov. 30, 2020 USD ($) candidate	Aug. 31, 2020 item	Apr. 30, 2020 USD ($)	Jan. 31, 2020 compound	Jun. 30, 2016 target	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 option	Dec. 31, 2022 USD ($) program	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) target	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 30, 2022 USD ($)	Mar. 31, 2020 USD ($)	Feb. 28, 2019 USD ($)
Collaboration research and licensing agreements
Receivable		$ 66,384,000													$ 28,997,000	$ 66,384,000
Unrealized gain (losses) recognized on equity securities															23,434,000	20,988,000	$ 105,000
Realized gain on investment															0	18,301,000
Net gains recognized on equity securities															23,434,000	39,289,000	105,000
Proceeds from sale of common stock																28,920,000
Zenas
Collaboration research and licensing agreements
Increase in estimated fair value of equity securities																				$ 17,900,000
Zenas \| Warrant
Collaboration research and licensing agreements
Equity shares estimated fair value																				34,500,000
Zenas \| Convertible Debt Securities
Collaboration research and licensing agreements
Equity shares estimated fair value																				$ 7,700,000
License, Development, and Commercialization Agreement \| Aimmune
Collaboration research and licensing agreements
Revenue recognized															0	0
Deferred revenue		0													0	0
Option and license agreement \| Alexion
Collaboration research and licensing agreements
Revenue recognized															29,400,000	22,200,000	26,200,000
Deferred revenue															0
Receivable															14,800,000
Option and license agreement \| Alexion \| Royalties
Collaboration research and licensing agreements
Revenue recognized															29,400,000	22,200,000	16,200,000
Option and license agreement \| Alexion \| Milestone
Collaboration research and licensing agreements
Revenue recognized																	10,000,000
Research and License Agreement \| Amgen, Inc.
Collaboration research and licensing agreements
Revenue recognized															0	0	0
Deferred revenue															$ 0
Research and License Agreement \| Amgen, Inc. \| Discovery Program
Collaboration research and licensing agreements
Number of discovery programs in clinical development \| program															1
Research and License Agreement \| Astellas
Collaboration research and licensing agreements
Revenue recognized															$ 5,000,000		2,500,000
Deferred revenue															0
Proceeds from milestone payments															5,000,000
Research and License Agreement \| Novartis \| Milestone
Collaboration research and licensing agreements
Revenue recognized																3,000,000
Collaboration and License Agreement \| Genentech
Collaboration research and licensing agreements
Revenue recognized															0	2,500,000	3,500,000
Transaction price																						$ 120,000,000
Cost sharing receivable (payable)															200,000
Collaboration and License Agreement \| Genentech \| XmAb306
Collaboration research and licensing agreements
Standalone selling price																						111,700,000
Collaboration and License Agreement \| Genentech \| XmAb435
Collaboration research and licensing agreements
Standalone selling price																					$ 4,100,000
Collaboration and License Agreement \| Genentech \| Research service
Collaboration research and licensing agreements
Deferred revenue															0
Transaction price															8,300,000
Standalone selling price																						$ 4,200,000
Collaboration and License Agreement \| Janssen
Collaboration research and licensing agreements
Revenue recognized		5,000,000													0		0
Deferred revenue															30,300,000
Transaction price							$ 50,000,000
Percentage of funding for development costs							20.00%
Percentage of co-detailing activities							30.00%
Research license term	2 years
Number of collaboration and license agreements \| agreement	2
Collaboration and License Agreement \| Janssen \| Research collaboration
Collaboration research and licensing agreements
Revenue recognized																50,000,000
Collaboration and License Agreement \| MorphoSys
Collaboration research and licensing agreements
Revenue recognized																	39,000,000
Deferred revenue															0
Collaboration and License Agreement \| MorphoSys \| Royalties
Collaboration research and licensing agreements
Revenue recognized															7,800,000	5,900,000
Contract asset															2,200,000
Collaboration and License Agreement \| MorphoSys \| Milestone
Collaboration research and licensing agreements
Revenue recognized																12,500,000
Collaboration and License Agreement \| Novartis
Collaboration research and licensing agreements
Revenue recognized															0	43,100,000	0
Deferred revenue															0
Receivable															$ 30,000.00
Collaboration and License Agreement \| Novartis \| Global Discovery Program
Collaboration research and licensing agreements
Revenue recognized																40,100,000			$ 40,100,000
Number of programs delivered \| program															2
Collaboration and License Agreement \| Novartis \| FC Licenses \| Maximum
Collaboration research and licensing agreements
Number of targets against which non-exclusive license is provided \| target											10
Collaboration and License Agreements \| Janssen
Collaboration research and licensing agreements
Revenue recognized															$ 7,000,000	113,800,000
License Agreement \| INmune
Collaboration research and licensing agreements
Unrealized gain (losses) recognized on equity securities															(7,300,000)	15,100,000
Consideration on sale of option					$ 18,300,000
Cash consideration on sale of option					15,000,000
Realized gain on investment					18,300,000											18,300,000
License Agreement \| INmune \| Common Stock
Collaboration research and licensing agreements
Unrealized gain (losses) recognized on equity securities												$ 2,000,000
Cash consideration on sale of option					15,000,000
Purchase amount of share options or equity in noncash transaction				$ 800,000
Gain on fair value of option												1,100,000
Net gains recognized on equity securities				$ 900,000
License Agreement \| INmune \| Other Income
Collaboration research and licensing agreements
Unrealized gain (losses) recognized on equity securities													$ 27,800,000
License Agreement \| INmune \| Other Income \| Common Stock
Collaboration research and licensing agreements
Net gains recognized on equity securities												$ 900,000
License Agreement \| Zenas
Collaboration research and licensing agreements
Revenue recognized															0	14,900,000	16,100,000
Deferred revenue															$ 0
Transaction price			$ 14,900,000				$ 16,100,000
Purchase amount of share options or equity in noncash transaction							$ 16,100,000
Number of drug candidates \| candidate							3
Number of collaboration and license agreements \| program															2
Percentage of equity of private company			15.00%				15.00%
Milestones or royalties in transaction price			$ 0				$ 0
Patent License Agreement \| Vir
Collaboration research and licensing agreements
Revenue recognized															$ 115,400,000	52,700,000	$ 300,000
Deferred revenue															0
Receivable															4,800,000
Potential milestone payment																		$ 154,000,000
Number of different target programs \| target																	2
Upfront and milestone payment received																		2,000,000
Contract asset					$ 500,000								$ 500,000
Patent License Agreement \| Vir \| Royalties
Collaboration research and licensing agreements
Revenue recognized															114,900,000	52,200,000
Second Collaboration And License Agreement \| Janssen
Collaboration research and licensing agreements
Transaction price	$ 96,100,000
Research license term	2 years
Nonrefundable upfront payment	$ 100,000,000
Potential milestone payment	1,187,500,000
Proceeds from sale of common stock	$ 28,900,000
Share development percentage	80.00%
Percentage of responsibility for development costs	20.00%
Number of candidates for which option to advance for development and commercialization \| candidate	4
Number of drug candidates \| candidate	4
Discount on proceeds from sale	$ 3,900,000
Second Collaboration And License Agreement \| Janssen \| Research service
Collaboration research and licensing agreements
Revenue recognized															7,000,000	300,000
Standalone selling price	37,600,000
Performance obligation	37,600,000		37,600,000
Second Collaboration And License Agreement \| Janssen \| Licensing
Collaboration research and licensing agreements
Revenue recognized	58,500,000		58,500,000
Standalone selling price	58,500,000
Second Collaboration And License Agreement \| Johnson & Johnson Innovation, JJDC, Inc. \| Common Stock
Collaboration research and licensing agreements
Proceeds from sale of common stock	$ 25,000,000
Number of trading days \| d	30
Weighted average price (in dollars per share) \| $ / shares	$ 33.4197
Total equity shares (in shares) \| shares	748,062
Second Collaboration And License Agreement \| Zenas
Collaboration research and licensing agreements
Potential milestone payment			470,000,000
Warrants			$ 14,900,000
Licensing Agreements \| INmune
Collaboration research and licensing agreements
Revenue recognized															0	0	$ 0
Technology License Agreement \| Astria/Catabasis
Collaboration research and licensing agreements
Deferred revenue															0
Impairment charge															100,000
Unrealized gain (losses) recognized on equity securities															6,100,000	4,500,000
Technology License Agreement \| Gilead
Collaboration research and licensing agreements
Revenue recognized									$ 7,500,000						0	0	13,500,000
Deferred revenue															0
Number of additional antibody compounds \| compound										3
Number of options exercised \| option														3
Technology License Agreement \| Viridian
Collaboration research and licensing agreements
Revenue recognized															0	7,500,000	6,000,000
Deferred revenue															0
Purchase amount of share options or equity in noncash transaction		$ 7,500,000				$ 6,000,000
Research license term		1 year
Number of antibodies \| candidate		3
Technology License Agreement \| Viridian \| Maximum
Collaboration research and licensing agreements
Potential milestone payment		$ 24,800,000														24,800,000
Technology License Agreement \| Viridian \| Xtend Fc Technology
Collaboration research and licensing agreements
Transaction price						$ 6,000,000											6,000,000
Technology License Agreement \| Viridian \| Antibody Libraries
Collaboration research and licensing agreements
Transaction price		7,500,000														7,500,000
Technology License Agreement \| Omeros
Collaboration research and licensing agreements
Revenue recognized															0	0	$ 5,000,000
Deferred revenue															$ 0
Number of additional antibodies \| item								3
Development-based \| Patent License Agreement \| Vir
Collaboration research and licensing agreements
Potential milestone payment																		4,000,000
Development-based \| Second Collaboration And License Agreement \| Janssen
Collaboration research and licensing agreements
Potential milestone payment	$ 289,400,000
Development-based \| Technology License Agreement \| Viridian
Collaboration research and licensing agreements
Potential milestone payment		1,800,000														1,800,000
Regulatory-based \| Patent License Agreement \| Vir
Collaboration research and licensing agreements
Potential milestone payment																		30,000,000
Regulatory-based \| Second Collaboration And License Agreement \| Janssen
Collaboration research and licensing agreements
Potential milestone payment	378,100,000
Regulatory-based \| Technology License Agreement \| Viridian
Collaboration research and licensing agreements
Potential milestone payment		3,000,000														3,000,000
Sales-based \| Patent License Agreement \| Vir
Collaboration research and licensing agreements
Potential milestone payment																		$ 120,000,000
Sales-based \| Second Collaboration And License Agreement \| Janssen
Collaboration research and licensing agreements
Potential milestone payment	$ 520,000,000
Sales-based \| Technology License Agreement \| Viridian
Collaboration research and licensing agreements
Potential milestone payment		$ 20,000,000														$ 20,000,000

Collaboration and Licensing Agreements - Revenue Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaboration research and licensing agreements
Revenue recorded	$ 164,579	$ 275,111	$ 122,694
Research collaboration
Collaboration research and licensing agreements
Revenue recorded	7,000	93,000	4,500
Milestone
Collaboration research and licensing agreements
Revenue recorded	5,500	21,000	50,200
Licensing
Collaboration research and licensing agreements
Revenue recorded	0	80,800	50,200
Royalties
Collaboration research and licensing agreements
Revenue recorded	152,100	80,300	17,800
Aimmune
Collaboration research and licensing agreements
Revenue recorded	0	0	9,600
Alexion
Collaboration research and licensing agreements
Revenue recorded	29,400	22,200	26,200
Astellas
Collaboration research and licensing agreements
Revenue recorded	5,000	0	3,500
Genentech
Collaboration research and licensing agreements
Revenue recorded	0	2,500	3,500
Gilead
Collaboration research and licensing agreements
Revenue recorded	0	0	13,500
Janssen
Collaboration research and licensing agreements
Revenue recorded	7,000	113,800	0
MorphoSys
Collaboration research and licensing agreements
Revenue recorded	7,800	18,400	39,000
Novartis
Collaboration research and licensing agreements
Revenue recorded	0	43,100	0
Omeros
Collaboration research and licensing agreements
Revenue recorded	0	0	5,000
Vir
Collaboration research and licensing agreements
Revenue recorded	115,400	52,700	300
Viridian
Collaboration research and licensing agreements
Revenue recorded	0	7,500	6,000
Zenas
Collaboration research and licensing agreements
Revenue recorded	$ 0	$ 14,900	$ 16,100

401(k) Plan (Details) - USD ($) $ in Millions			12 Months Ended
401(k) Plan (Details) - USD ($) $ in Millions	Mar. 31, 2020	Jan. 01, 2018	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan employer matching contribution percent	4.00%	3.50%
Vesting period			3 years
Annual vesting percentage			33.00%
Employer contributions			$ 1.4	$ 1.1	$ 0.8
1% of participating employee contributions
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching to defined contribution plan	100.00%	100.00%
Defined contribution plan employer matching contribution percent	1.00%	1.00%
5% of participating employee contributions
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching to defined contribution plan		50.00%
Defined contribution plan employer matching contribution percent		5.00%
6% of participating employee contributions
Defined Benefit Plan Disclosure [Line Items]
Percentage of company matching to defined contribution plan	50.00%
Defined contribution plan employer matching contribution percent	6.00%