Xencor (XNCR) 10-K 24 Feb 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 16, 2022	Jun. 30, 2021
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
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 Common Stock, Shares Outstanding		59,375,320
Entity Central Index Key	0001326732
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Public Float			$ 2,000,288,972
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Auditor Name	RSM US LLP
Auditor Firm ID	49
Auditor Location	Los Angeles, California

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 143,480	$ 163,544
Marketable debt securities	153,767	434,156
Marketable equity securities	36,860	5,303
Accounts receivable	66,384	11,443
Contract asset		12,500
Prepaid expenses and other current assets	23,877	10,726
Total current assets	424,368	637,672
Property and equipment, net	28,240	21,682
Patents, licenses, and other intangible assets, net	16,493	15,977
Marketable debt securities - long term	300,465	1,030
Marketable equity securities - long term	31,262	16,071
Notes receivable - long term	5,000
Right-of-use assets	31,730	10,600
Other assets	653	212
Total assets	838,211	703,244
Current liabilities
Accounts payable	14,001	8,954
Accrued expenses	19,443	17,603
Lease liabilities		1,889
Deferred revenue	37,294	92,615
Total current liabilities	70,738	121,061
Lease liabilities, net of current portion	33,969	9,739
Total liabilities	104,707	130,800
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, 2021 and 2020
Common stock, $0.01 par value: 200,000,000 authorized shares; 59,355,558 issued and outstanding shares at December 31, 2021 and 557,873,444 issued and outstanding at December 31, 2020	595	580
Additional paid-in capital	1,017,523	937,525
Accumulated other comprehensive income	(1,510)	74
Accumulated deficit	(283,104)	(365,735)
Total stockholders' equity	733,504	572,444
Total liabilities and stockholders' equity	$ 838,211	$ 703,244

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	59,355,558	57,873,444
Common stock, shares outstanding	59,355,558	57,873,444

Statements of Comprehensive Inc

Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue
Collaborations, licenses, milestones, and royalties	$ 275,111	$ 122,694	$ 156,700
Operating expenses
Research and development	192,507	169,802	118,590
General and administrative	38,837	29,689	24,286
Total operating expenses	231,344	199,491	142,876
Income (loss) from operations	43,767	(76,797)	13,824
Other income (expenses)
Interest income, net	849	7,264	13,619
Other income (expense), net	(1,274)	95	(256)
Gain on equity securities, net	39,289	105
Total other income, net	38,864	7,464	13,363
Income (loss) before income tax	82,631	(69,333)	27,187
Income tax expense	0	0	312
Net income (loss)	82,631	(69,333)	26,875
Other comprehensive income (loss)
Net unrealized gain (loss) on marketable debt securities	(1,584)	(1,087)	2,132
Comprehensive income (loss)	$ 81,047	$ (70,420)	$ 29,007
Net income (loss) per share attributable to common stockholders:
Basic net income (loss) (in dollars per share)	$ 1.42	$ (1.21)	$ 0.48
Diluted net income (loss) (in dollars per share)	$ 1.37	$ (1.21)	$ 0.46
Weighted average shares used to compute net income (loss) per share attributable to common stockholders:
Basic (in shares)	58,379,641	57,212,737	56,531,439
Diluted (in shares)	60,495,455	57,212,737	58,467,880

Statements of Stockholders' Equ

Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at Dec. 31, 2018	$ 563	$ 845,366	$ (971)	$ (323,277)	$ 521,681
Balance (in shares) at Dec. 31, 2018	56,279,542
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock awards	$ 5	9,264			9,269
Issuance of common stock upon exercise of stock awards (in shares)	543,887
Issuance of restricted stock units (in shares)	11,311
Issuance of common stock under the Employee Stock Purchase Plan	$ 1	1,392			1,393
Issuance of common stock under the Employee Stock Purchase Plan (in shares)	67,561
Comprehensive income (loss)			2,132	26,875	29,007
Stock-based compensation		31,851			31,851
Balance at Dec. 31, 2019	$ 569	887,873	1,161	(296,402)	593,201
Balance (in shares) at Dec. 31, 2019	56,902,301
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock awards	$ 9	16,608			16,617
Issuance of common stock upon exercise of stock awards (in shares)	858,470
Issuance of restricted stock units	$ 1	(1)
Issuance of restricted stock units (in shares)	62,355
Issuance of common stock under the Employee Stock Purchase Plan	$ 1	1,426			1,427
Issuance of common stock under the Employee Stock Purchase Plan (in shares)	50,318
Comprehensive income (loss)			(1,087)	(69,333)	(70,420)
Stock-based compensation		31,619			31,619
Balance at Dec. 31, 2020	$ 580	937,525	74	(365,735)	572,444
Balance (in shares) at Dec. 31, 2020	57,873,444
Increase (Decrease) in Stockholders' Equity
Sale of common stock	$ 7	28,913			28,920
Sale of common stock (in shares)	748,062
Issuance of common stock upon exercise of stock awards	$ 5	12,276			12,281
Issuance of common stock upon exercise of stock awards (in shares)	520,240
Issuance of restricted stock units	$ 2	(2)
Issuance of restricted stock units (in shares)	151,555
Issuance of common stock under the Employee Stock Purchase Plan	$ 1	1,836			1,837
Issuance of common stock under the Employee Stock Purchase Plan (in shares)	62,257
Comprehensive income (loss)			(1,584)	82,631	81,047
Stock-based compensation		36,975			36,975
Balance at Dec. 31, 2021	$ 595	$ 1,017,523	$ (1,510)	$ (283,104)	$ 733,504
Balance (in shares) at Dec. 31, 2021	59,355,558

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net income (loss)	$ 82,631	$ (69,333)	$ 26,875
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	7,491	5,794	4,298
Amortization of premium (accretion of discount) on marketable securities	3,160	(272)	(4,321)
Stock-based compensation	36,975	31,619	31,851
Abandonment of capitalized intangible assets	934	535	221
Loss on disposal of assets	462	4	8
Gain on sale of marketable securities available-for-sale		(153)
Equity received in connection with license agreement	(22,379)	(26,660)
Equity received in connection with sale of financial assets	(3,300)
Cash redemption of equity received in connection with license agreement		5,390
Change in fair value of equity securities	(20,988)	(105)
Equity securities impairment	762
Changes in operating assets and liabilities:
Accounts receivable	(54,941)	10,131	(11,321)
Interest receivable from marketable debt securities	655	1,190	(387)
Prepaid expenses and other current assets	(13,151)	(4,170)	3,828
Income tax receivable		895	704
Contract asset and deposits	12,059	(12,401)
Accounts payable	5,047	(1,235)	6,392
Accrued expenses	1,840	8,608	(667)
Deferred rent			(1,513)
Lease liabilities and right of use (ROU) assets	1,211	(325)	1,354
Deferred revenue	(55,321)	45,484	7,052
Net cash provided by (used in) operating activities	(16,853)	(5,004)	64,374
Cash flows from investing activities
Proceeds from sale and maturities of marketable securities available-for-sale	485,152	757,617	456,923
Proceeds from sale of property and equipment	19	1
Purchase of marketable securities	(509,597)	(643,658)	(496,855)
Purchase of intangible assets	(2,682)	(3,229)	(3,685)
Purchase of property and equipment	(13,299)	(10,539)	(7,353)
Purchase of convertible note	(5,000)
Exercise of stock options	(842)
Net cash provided by (used in) investing activities	(46,249)	100,192	(50,970)
Cash flows from financing activities
Proceeds from issuance of common stock upon exercise of stock awards	12,281	16,617	9,269
Proceeds from issuance of common stock from Employee Stock Purchase Plan	1,837	1,427	1,393
Proceeds from issuance of common stock	28,920
Net cash provided by financing activities	43,038	18,044	10,662
Net (decrease) increase in cash and cash equivalents	(20,064)	113,232	24,066
Cash and cash equivalents, beginning of year	163,544	50,312	26,246
Cash and cash equivalents, end of year	143,480	163,544	50,312
Cash paid for:
Interest	14	15	11
Taxes			400
Supplemental disclosures of non-cash investing activities
Unrealized loss on marketable securities	$ (1,584)	$ (1,087)	$ 2,132

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	1. 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, 2021, 2020, and 2019 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 adopted in 2021 Effective January 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes Effective January 1, 2021, the Company adopted ASU No. 2020-01, which clarifies that a company should consider observable transactions that require a company to either apply or discontinue the equity method of accounting under Topic 323, Investment – Equity Method and Joint Ventures Investments – Equity Securities Effective January 1, 2021, the Company adopted ASU No. 2020-10, Codification Improvements Pronouncements not yet effective There are accounting standards that have been issued by the Financial Accounting Standards Board (FASB) but are not yet effective. The standards are not expected to have a material impact on our results of operations, financial conditions, or cash flows. 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 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 $37.3 million and $92.6 million at December 31, 2021 and 2020, 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 allowance for doubtful accounts at December 31, 2021 or 2020, 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, 2021 and 2020, respectively. Accrued interest on marketable debt securities is included in marketable securities’ carrying value. Accrued interest was $0.8 million and $1.4 million at December 31, 2021 and 2020, 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. 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. 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, 2021 and 2020 approximated $143.2 million and $163.3 million, respectively. We have payables with four service providers that represent 64% of our total payables and with one service provider that represented 49% of our total payables at December 31, 2021 and 2020, respectively. We rely on four 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, 2021 or 2020. We have receivables with two service providers that represent 84% and 88% of our total receivables at December 31, 2021 and 2020, 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, 2021 or 2020. 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 Level 1— Level 2— Level 3— 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, 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 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money Market Funds in Cash and Cash Equivalents ​ $ 158,937 ​ $ 158,937 ​ $ — ​ $ — Corporate Securities ​ ​ 119,833 ​ ​ — ​ ​ 119,833 ​ ​ — Government Securities ​ ​ 315,353 ​ ​ — ​ ​ 315,353 ​ ​ — ​ ​ $ 594,123 ​ $ 158,937 ​ $ 435,186 ​ $ — ​ 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, 2021 and 2020, 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 2021, 2020, and 2019, we abandoned previously capitalized patent and licensing related charges of $0.9 million, $0.5 million, and $0.2 million, respectively. The carrying amount and accumulated amortization of patents, licenses, and other intangibles is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 Patents, definite life $ 13,231 $ 12,038 ​ Patents, pending issuance ​ ​ 8,821 ​ 8,432 ​ Licenses and other amortizable intangible assets ​ ​ 2,474 ​ 2,560 ​ Nonamortizable intangible assets (trademarks) ​ ​ 399 ​ 399 ​ Total gross carrying amount ​ ​ 24,925 ​ 23,429 ​ Accumulated amortization—patents ​ ​ (6,800) ​ (5,791) ​ Accumulated amortization—licenses and other ​ ​ (1,632) ​ (1,661) ​ Total intangible assets, net ​ $ 16,493 ​ $ 15,977 ​ ​ Amortization expense for patents, licenses, and other intangible assets was $1.2 million, $1.1 million, and $0.9 million for the years ended December 31, 2021, 2020, and 2019, respectively. Future amortization expense for patent, licenses, and other intangible assets recorded as of December 31, 2021, and for which amortization has commenced, is as follows: ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, ​ ​ (in thousands) 2022 ​ $ 1,073 ​ 2023 ​ ​ 957 ​ 2024 ​ ​ 770 ​ 2025 ​ ​ 680 ​ 2026 ​ ​ 586 ​ Thereafter ​ ​ 3,207 ​ Total ​ $ 7,273 ​ ​ 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, 2021, the Company has $8.8 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, 2021, 2020, or 2019. 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, 2021 or 2020. 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 tax reform provided for a refund of unused AMT carryforwards for years beginning after December 31, 2017. We received an income tax refund during the years ended December 31, 2020 and 2019 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 $37.0 million, $31.6 million, and $31.9 million for the years ended December 31, 2021, 2020, and 2019, 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 and 2019. In 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, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands, except share and per share data) Basic ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common stockholders for basic net income (loss) per share ​ $ 82,631 ​ $ (69,333) ​ $ 26,875 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding ​ ​ 58,379,641 ​ 57,212,737 ​ 56,531,439 ​ Basic net income (loss) per common share ​ $ 1.42 ​ $ (1.21) ​ $ 0.48 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common stockholders for diluted net income (loss) per share ​ $ 82,631 ​ $ (69,333) ​ $ 26,875 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding used in computing basic net income (loss) per common share ​ ​ 58,379,641 ​ 57,212,737 ​ 56,531,439 ​ Dilutive effect of employee stock options, RSUs, and ESPP ​ ​ 2,115,814 ​ — ​ 1,936,441 ​ Weighted-average number of common shares outstanding used in computing diluted net income (loss) per common share ​ ​ 60,495,455 ​ 57,212,737 ​ 58,467,880 ​ Diluted net income (loss) per common share ​ $ 1.37 ​ $ (1.21) ​ $ 0.46 ​ ​ 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. For the year ended December 31, 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, 2019, we excluded 1,022,623 shares of options and RSUs from the calculation 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)

Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2021
Comprehensive Income (Loss)
Comprehensive Income (Loss)	2. Comprehensive Income (Loss) Comprehensive income (loss) is comprised of net income (loss) and other comprehensive income (loss). For the years ended December 31, 2021, 2020, and 2019, 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, 2021.

Marketable Debt and Equity Secu

Marketable Debt and Equity Securities	12 Months Ended
	Dec. 31, 2021
Marketable Debt and Equity Securities
Marketable Debt and Equity Securities	3. Marketable Debt and Equity Securities The Company’s marketable debt securities held as of December 31, 2021 and 2020 are summarized below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized Unrealized ​ Unrealized ​ ​ ​ Cost ​ Gains ​ 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized Unrealized ​ Unrealized ​ ​ ​ Cost ​ Gains ​ Losses ​ Fair Value (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money Market Funds ​ $ 158,937 ​ $ — ​ $ — ​ $ 158,937 Corporate Securities ​ ​ 119,782 ​ ​ 57 ​ ​ (6) ​ ​ 119,833 Government Securities ​ ​ 315,319 ​ ​ 37 ​ ​ (3) ​ ​ 315,353 ​ ​ $ 594,038 ​ $ 94 ​ $ (9) ​ $ 594,123 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reported as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 158,937 Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 435,186 Total investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 594,123 ​ The maturities of the Company’s marketable debt securities as of December 31, 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Estimated ​ ​ Cost ​ Fair Value (in thousands) ​ ​ ​ ​ ​ ​ Mature in one year or less ​ $ 153,871 ​ $ 153,767 Mature within two years ​ ​ 301,861 ​ ​ 300,465 ​ ​ $ 455,732 ​ $ 454,232 ​ The unrealized losses on available-for-sale investments and their related fair values as of December 31, 2021 and 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Less than 12 months ​ 12 months or greater ​ ​ ​ Fair value ​ ​ Unrealized losses ​ ​ Fair value ​ ​ Unrealized losses (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate Securities ​ $ 15,843 ​ $ (6) ​ $ — ​ $ — Government Securities ​ ​ 40,802 ​ ​ (3) ​ ​ — ​ ​ — ​ ​ $ 56,645 ​ $ (9) ​ $ — ​ $ — ​ 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, 2021 and 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Fair Value ​ ​ December 31, 2021 ​ December 31, 2020 Astria Common Stock ​ $ 3,449 ​ $ — INmune Common Stock ​ ​ 19,233 ​ ​ — Viridian Common Stock ​ ​ 14,178 ​ ​ 5,303 ​ ​ $ 36,860 ​ $ 5,303 ​ The Company also has investments in equity securities without a readily determinable fair value. The Company elects the measurement alternative to record these investments at their initial cost and evaluate such investments at each reporting period for evidence of impairment, or observable price changes in orderly transactions for the identical or a similar investment of the same issuer. During the year ended December 31, 2021, the Company recorded an impairment charge of $0.8 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, 2021 and 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Value Carrying Value ​ ​ December 31, 2021 ​ December 31, 2020 Astria Preferred Stock ​ $ 312 ​ $ — Zenas Preferred Stock ​ ​ 30,950 ​ ​ 16,071 ​ ​ $ 31,262 ​ $ 16,071 ​ In 2018, the Company received equity shares in Quellis Biosciences, Inc. (Quellis) in connection with a licensing transaction. The Company recorded the Quellis equity as securities without a readily determinable fair value, and the investment was recorded at its original cost. In 2021, Quellis merged into Catabasis Pharmaceuticals, Inc. (Catabasis), and the Company received 259,206 shares of common stock and 3,928 shares of preferred stock in Catabasis in exchange for its Quellis equity. In June 2021, 3,581 shares of the Catabasis preferred stock were exchanged for 3,580,539 shares of Catabasis common stock. The total 3,839,745 shares of the Catabasis common stock have a readily determinable fair value. In August 2021, Catabasis effected a reverse stock split of its shares of common stock at a ratio of 1 :6, and in September 2021, Catabasis changed its name to Astria Therapeutics, Inc. (Astria). 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, 2021. 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 3,928 shares of preferred stock at their initial cost of $12.1 million and to review the carrying value for impairment or other changes in carrying value at each reporting period. After the conversion of 3,581 shares of Astria preferred stock to common stock in June 2021, the Company owned 347 shares of preferred stock and continued to carry the shares at their original cost of $1.1 million. The Company subsequently recorded impairment charges of $0.8 million related to its investment in Astria’s preferred stock. In 2017, the Company received 1,585,000 shares of common stock of INmune Bio, Inc. (INmune) and an option to acquire an additional 10% of INmune’s outstanding shares of common stock in connection with a licensing transaction. The Company also received an option to acquire 108,000 shares of INmune common stock in connection with a designee appointed by us serving on the board of directors of INmune. The Company initially recorded its equity interest, including its option to acquire additional equity in INmune, at cost pursuant to ASC 323, Investments – Equity Method and Joint Ventures In December 2020, the Company received 322,407 shares of common stock of Viridian Therapeutics, Inc. (Viridian) in connection with the Viridian Agreement (defined below). In December 2021, the Company received an additional 394,737 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, 2021. 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 the 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). During the year ended December 31, 2021, there have not been any impairment or observable price changes related to this investment. Unrealized gains and losses recognized on equity securities (in thousands) during the year ended December 31, 2021 and 2020 consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ 2020 ​ ​ ​ Net gains recognized on equity securities ​ $ 39,289 ​ $ 105 Less: net gains recognized on equity securities redeemed ​ ​ 18,301 ​ 801 Unrealized gain (losses) recognized on equity securities ​ $ 20,988 ​ $ (696) ​

Sale of Additional Common Stock

Sale of Additional Common Stock	12 Months Ended
	Dec. 31, 2021
Sale of Additional Common Stock
Sale of Additional Common Stock	4. Sale of Additional Common Stock ​ Under 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

Property and Equipment	12 Months Ended
	Dec. 31, 2021
Property and Equipment
Property and Equipment	5. Property and Equipment Property and equipment consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Computers, software and equipment $ 41,955 $ 31,229 ​ Furniture and fixtures ​ ​ 539 ​ 527 ​ Leasehold and tenant improvements ​ ​ 8,574 ​ 6,957 ​ Total gross carrying amount ​ ​ 51,068 ​ 38,713 ​ Less accumulated depreciation and amortization ​ (22,828) ​ (17,031) ​ Total property and equipment, net ​ $ 28,240 ​ $ 21,682 ​ ​ Depreciation expense related to property and equipment in 2021, 2020, and 2019 was $6.3 million, $4.7 million, and $3.4 million, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Taxes
Income Taxes	6. Inc ome Taxes Our effective tax rate differs from the statutory federal income tax rate, primarily as a result of the changes in valuation allowance. There was no provision for taxes for the years ended December 31, 2021 and December 31, 2020. The provision for income taxes for the year ended December 31, 2019 was $0.3 million, which represents the current state alternative minimum tax for the year. A reconciliation of the federal statutory income tax to our effective income tax is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 Federal statutory income tax $ 17,352 $ (14,559) $ 5,709 ​ State and local income taxes ​ ​ 783 ​ ​ (4,659) ​ 2,549 ​ Research and development credit ​ (10,492) ​ (9,669) ​ (6,747) ​ Stock-based compensation ​ ​ 2,424 ​ ​ 529 ​ ​ 1,927 ​ State credit ​ ​ — ​ ​ — ​ ​ 1,725 ​ Other ​ ​ 95 ​ ​ 56 ​ (301) ​ Change in state rate ​ ​ 2,599 ​ ​ — ​ ​ — ​ Net change in valuation allowance ​ ​ (12,761) ​ ​ 28,302 ​ (4,550) ​ Income tax provision ​ $ — ​ $ — ​ $ 312 ​ The tax effect of temporary differences that give rise to a significant portion of the deferred tax assets and liabilities at December 31, 2021 and 2020 is presented below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 2020 ​ Deferred income tax assets ​ ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 46,629 ​ $ 56,182 ​ Research credits ​ ​ 48,128 ​ 38,047 ​ Unrealized loss on securities ​ ​ 327 ​ 195 ​ Capitalized lease assets ​ ​ 489 ​ ​ 288 ​ Accrued compensation ​ ​ 9,207 ​ 8,464 ​ Deferred revenue ​ ​ — ​ 11,925 ​ Gross deferred income tax assets ​ ​ 104,780 ​ 115,101 ​ Valuation allowance ​ (93,580) ​ (105,995) ​ Net deferred income tax assets ​ ​ 11,200 ​ 9,106 ​ Deferred income tax liabilities ​ ​ ​ ​ ​ ​ ​ Patent costs ​ (3,416) ​ (4,219) ​ Equity investment ​ ​ (3,508) ​ ​ (4,497) ​ Licensing costs ​ (151) ​ (194) ​ Capitalized legal costs ​ (13) ​ (21) ​ Depreciation ​ ​ (288) ​ ​ (151) ​ Unrealized gain on securities ​ ​ (3,824) ​ ​ (24) ​ Gross deferred income tax liabilities ​ (11,200) ​ (9,106) ​ 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 as of December 31, 2017. We have received an income tax refund of $0.8 million and $0.8 million for each year ended December 31, 2020 and 2019 for U.S. AMT credit carryforwards. 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, 2021 and 2020. 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, 2021, the valuation allowance decreased by $12.4 million. The Company’s tax years starting in 2017 through 2020 remain open to potential examination by the U.S. and state taxing authorities due to carryforwards of net operating losses. As of December 31, 2021, we had cumulative net operating loss carryforwards for federal and state income tax purposes of $168.2 million and $161.6 million, respectively, and available tax credit carryforwards of approximately $34.0 million for federal income tax purposes and $17.8 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 $63.9 million of losses incurred prior to January 1, 2018, which are subject to carryforward limitations and $104.3 million of losses incurred after January 1, 2018, which may be carried forward indefinitely. Our federal net operating loss carryforwards expire starting in 2026, state net operating loss carryforwards expire starting in 2035, and federal tax credit carryforwards began to expire in 2019. A total of $0.5 million in federal tax credits will expire over the next four years if not utilized. 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.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Stock-Based Compensation
Stock-Based Compensation	7. 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, 2021, the total number of shares of common stock available for issuance under the 2013 Plan was 13,122,238. 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, 2021, the total number of shares of common stock available for issuance under the 2013 Plan was increased by 2,314,937 shares, which is included in the number of shares available for issuance above. As of December 31, 2021, a total of 12,400,073 options have been granted under the 2013 Plan. As of December 31, 2021, the Company has awarded 1,124,487 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. We have reserved a total of 581,286 shares of common stock for issuance under the ESPP. 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. On January 1, 2014, the total number of shares of common stock available for issuance under the ESPP was automatically increased by 313,545 shares, which is included in the number of shares reserved for issuance above. Pursuant to approval by our board, there were no increases in the number of authorized shares in the ESPP in years from 2015 to 2021. As of December 31, 2021, we have issued a total of 529,852 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) ​ 2021 ​ 2020 ​ 2019 General and administrative $ 12,813 $ 10,769 $ 8,854 ​ Research and development ​ ​ 24,162 ​ ​ 20,850 ​ 22,997 ​ ​ ​ $ 36,975 ​ $ 31,619 ​ $ 31,851 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ (in thousands) ​ 2021 ​ 2020 ​ 2019 ​ Stock options $ 27,909 $ 26,045 $ 30,502 ​ ESPP ​ ​ 992 ​ 804 ​ 687 ​ RSUs ​ ​ 8,074 ​ 4,770 ​ 662 ​ ​ ​ $ 36,975 ​ $ 31,619 ​ $ 31,851 ​ ​ Information with respect to stock options outstanding is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 Exercisable options ​ 5,576,430 ​ 4,668,179 ​ 3,950,965 ​ Weighted average exercise price per share of exercisable options ​ $ 24.15 ​ $ 21.75 ​ $ 17.79 ​ Weighted average grant date fair value per share of options granted during the year ​ $ 21.65 ​ $ 16.96 ​ $ 20.74 ​ Options available for future grants ​ 3,597,371 ​ 3,346,092 ​ 3,975,160 ​ Weighted average remaining contractual life ​ 6.65 ​ 7.00 ​ 7.32 ​ ​ The following table summarizes stock option activity for the years ended December 31, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ ​ ​ ​ Exercise ​ Contractual ​ Aggregate ​ ​ Number of ​ Price ​ Term ​ Intrinsic Value ​ ​ Shares ​ (Per Share) (1) ​ (in years) ​ (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 ​ As of December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options vested and expected to vest 8,676,329 ​ $ 29.11 6.65 ​ $ 100,057 ​ Exercisable 5,576,430 ​ $ 24.15 5.53 ​ $ 89,287 ​ (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, 2021 and 2020. (3) The total intrinsic value of stock options exercised was $9.2 million, $16.3 million, and $11.5 million for the years ended December 31, 2021, 2020 and 2019 respectively. The stock options outstanding and exercisable by exercise price at December 31, 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock Options Outstanding ​ Stock Options Exercisable ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Remaining Weighted- ​ Weighted- Range of ​ ​ ​ Contractual ​ Average ​ ​ ​ Average Exercise ​ Number of ​ Term ​ Exercise Price ​ Number of ​ Exercise Price Prices ​ Shares ​ (in years) ​ Per Share ​ Shares ​ Per Share $4.25 – $10.28 151,488 1.68 ​ $ 4.29 151,488 ​ $ 4.29 ​ $10.52 – $15.78 1,508,709 3.33 ​ $ 13.15 1,507,724 ​ $ 13.15 ​ $15.91 – $23.87 1,777,216 5.52 ​ $ 22.77 1,756,016 ​ $ 22.76 ​ $23.96 – $35.94 ​ 2,312,270 ​ 7.91 ​ $ 32.08 ​ 1,168,530 ​ $ 31.65 ​ $35.99 – $53.99 ​ 2,926,646 ​ 8.31 ​ $ 40.12 ​ 992,672 ​ $ 37.52 ​ ​ 8,676,329 6.65 ​ $ 29.11 5,576,430 ​ $ 24.15 ​ ​ 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, 2021, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options ​ ​ 2021 2020 2019 Common stock fair value per share ​ $ 30.65 - 49.47 ​ $ 20.69 - 45.91 ​ $ 29.96 - 44.19 ​ Expected volatility ​ 53.91% - 56.82% ​ 52.93% - 58.95% ​ 60.67% - 61.33% ​ Risk-free interest rate ​ 0.47% - 1.33% ​ 0.29% - 1.71% ​ 1.37% - 2.60% ​ Expected dividend yield ​ — ​ — ​ — ​ Expected term (in years) ​ 6.00 - 7.65 ​ 5.23 - 7.65 ​ 5.23 - 6.59 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ESPP ​ ​ 2021 2020 2019 ​ Expected term (years) 0.5 - 2.0 0.5 - 2.0 0.5 - 2.0 ​ Expected volatility ​ 46.08% - 66.37% ​ 50.77% - 66.37% ​ 50.77% - 71.37% ​ Risk-free interest rate 0.04% - 1.65% ​ 0.09% - 1.65% ​ 1.47% - 2.70% ​ 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, 2021, 2020, and 2019 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, 2021. The following table summarizes RSU activity for the years ended December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ Number of ​ Fair Value ​ ​ Shares ​ (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 ​ As of December 31, 2021 and 2020, the unamortized compensation expense related to unvested stock options was $54.5 million and $48.9 million, respectively. The remaining unamortized compensation expense will be recognized over the next 2.62 years. At December 31, 2021 and 2020, the unamortized compensation expense was $2.3 million and $0.9 million respectively under our ESPP. The remaining unamortized expense will be recognized over the next 1.94 years. At December 31, 2021 and 2020, the unamortized compensation expense related to unvested restricted stock units was $24.8 million and $8.5 million, respectively. The remaining unamortized compensation expense will be recognized over the next 1.95 years.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases
Leases	8. Leases The Company leases office and laboratory space in Monrovia, California under a lease that expires in December 2025 with an option to renew for an additional five years at then market rates. In July 2017, under a separate lease agreement, the Company entered into a lease for additional space in the same building with a lease that continues through September 2022, also with an option to renew for an additional five years . The Company has assessed that it is unlikely to exercise either of the lease term extension options. The Company leases additional office space in San Diego, California through August 2022, with an option to extend for an additional five years . 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 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 second half of 2022. The term of the Halstead Lease will become effective in two phases. The first phase commences on July 1, 2022 and encompasses 83,083 square feet while the second phase commences no later than September 30, 2026 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 $17,032,015 and $3,252,000 in connection with the Phase 1 and Phase 2 building improvements, respectively. The initial base monthly rent is $386,335.95 , 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 as August 1, 2022 and to amend other provisions of the Halstead Lease to reflect the new start date of the lease. For the year ended December 31, 2021, ROU assets obtained in exchange for new operating lease liabilities are $29.7 million. In June 2021, the Company entered into an 18-month lease for a 7,020 -square-foot office space in Monrovia, California. The lease began on August 1, 2021, and the initial base monthly rent is $15,000.00 . The Company received delivery of the premises on July 19, 2021. For the year ended December 31, 2021, ROU assets obtained in exchange for new operating lease liabilities are $0.3 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, 2021 to the operating lease liabilities recorded on the balance sheet (in thousands): ​ ​ ​ ​ Years ending December 31, ​ ​ 2022 ​ $ 2,097 2023 ​ ​ 5,566 2024 ​ ​ 5,713 2025 ​ ​ 5,817 2026 ​ ​ 5,279 Thereafter ​ ​ 52,117 Total undiscounted lease payments ​ ​ 76,589 Less: Tenant allowance ​ ​ (17,032) Less: Imputed interest ​ ​ (25,588) Present value of lease payments ​ $ 33,969 ​ ​ ​ ​ Lease liabilities - long-term ​ $ 33,969 ​ The following table summarizes lease costs, cash, and other disclosures for the years ended December 31, 2021, 2020, and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 2020 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating lease cost ​ $ 4,342 ​ $ 2,503 ​ $ 2,596 Variable lease cost ​ ​ 58 ​ ​ 150 ​ ​ 80 Total lease costs ​ $ 4,400 ​ $ 2,653 ​ $ 2,676 Cash paid for amounts included in ​ ​ ​ ​ ​ ​ ​ ​ ​ the measurement of lease liabilities ​ $ 2,773 ​ $ 2,233 ​ $ 1,929 Weighted-average remaining lease term ​ ​ ​ ​ ​ ​ ​ ​ ​ —operating leases (in years) ​ ​ 12.3 ​ ​ 7.4 ​ ​ 5.5 Weighted-average discount rate ​ ​ ​ ​ ​ ​ ​ ​ ​ —operating leases ​ ​ 5.8% ​ ​ 5.5% ​ ​ 5.5% ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies
Commitments and Contingencies	​ 9. 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, 2021 and 2020.

Collaboration and Licensing Agr

Collaboration and Licensing Agreements	12 Months Ended
	Dec. 31, 2021
Collaboration and Licensing Agreements
Collaboration and Licensing Agreements	10. 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, 2021, 2020, and 2019. The revenue reported for each agreement has been adjusted to reflect the adoption of ASC 606 for each period presented. Aimmune Therapeutics, Inc. On February 4, 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. Under the Aimmune Agreement, Aimmune will be responsible for all further development and commercialization activities for XmAb7195. The Company received an upfront payment of $5.0 million and 156,238 shares of Aimmune common stock with an aggregate value of $4.6 million on the closing date. Under the Aimmune Agreement, the Company is also eligible to receive up to $385.0 million in milestones, which include $22.0 million in development milestones, $53.0 million in regulatory milestones and $310.0 million in sales milestones, and tiered royalties on net sales of approved products from high-single to mid-teen percentage range. Under the Aimmune Agreement, Aimmune received exclusive worldwide rights to manufacture, develop and commercialize XmAb7195. They also received the rights to all data, information and research materials related to the XmAb7195 program. The Company evaluated the Aimmune 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: ● license to the rights to the XmAb7195 drug candidate; and ● rights to material, data, and information that the Company had accumulated in connection with manufacturing, testing, and conducting clinical trials for the XmAb7195 program and intellectual property filings and information (XmAb7195 data). The Company considered the licenses as functional intellectual property as Aimmune has the right to use XmAb7195 at the time that the Company transfers such rights. The rights to the XmAb7195 data are not considered to be separate from the license to XmAb7195 as Aimmune cannot benefit from the license without the supporting data and documentation. The Company determined the transaction price at inception is $9.6 million which consists of the $5.0 million upfront payment and the 156,238 shares of Aimmune common stock which had a value of $4.6 million on the closing date. The Company determined that the transaction price is to be allocated to the performance obligations. The Aimmune Agreement includes variable consideration for potential future milestones and royalties that are contingent on future success factors for the XmAb7195 program. The Company used the “most likely amount” method to determine the variable consideration. None of the development, regulatory or sales milestones or 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 Aimmune Agreement and allocated it to the performance obligation, delivery of the XmAb7195 license. The Company completed delivery of its performance obligations in March 2020. The license to XmAb7195 was transferred to Aimmune at inception of the Aimmune Agreement, and the XmAb7195 data were transferred to Aimmune in March 2020. No revenue was recognized for the year ended December 31, 2021; the Company recognized $9.6 million of revenue related to the agreement for the year ended December 31, 2020. There is no deferred revenue as of December 31, 2021 or 2020 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 2019, Alexion completed certain regulatory submissions for Ultomiris, and the Company received a total of $8.0 million in milestone payments. During 2019, the Company also recorded royalty revenue of $5.0 million in connection with reported net sales of Ultomiris by Alexion. In 2020, the Company received $10.0 million for the achievement of certain sales milestones of Ultomiris in 2020 and also recorded royalty revenue of $16.2 million on net sales. In 2021, the Company recorded royalty revenue of $22.2 million on net sales. The total revenue recognized under this arrangement was $22.2 million, $26.2 million, and $13.0 million for the years ended December 31, 2021, 2020, and 2019, respectively. As of December 31, 2021, there is a receivable of $10.8 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. The Company also agreed to apply its bispecific technology to five previously identified Amgen provided targets (each a Discovery Program). Amgen has advanced one of the discovery programs into clinical development. The Company is eligible to receive up to $255.0 million in future development, regulatory and sales milestones in total for the program and is eligible to receive royalties on any global net sales of products. In the third quarter of 2019, a $5.0 million milestone was recognized in connection with a development milestone for a Discovery Program. During the year ended December 31, 2019, the Company recognized $5.0 million in revenue under this arrangement. No revenue was recognized for the year ended December 31, 2021, or 2020. As of December 31, 2021, there was no deferred revenue related to the arrangement. Astellas Pharma Inc. Effective March 29, 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. Pursuant to the Astellas Agreement, the Company applied its bispecific Fc technology to research antibodies provided by Astellas to generate bispecific antibody candidates and returned the candidates to Astellas for further development and commercialization. Astellas will assume full responsibility for development and commercialization of the antibody candidate. Pursuant to the Astellas Agreement, the Company received an upfront payment of $15.0 million and is eligible to receive up to $240.0 million in milestones, which include $32.5 million in development milestones, $57.5 million in regulatory milestones and $150.0 million in 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. The Company recognized the $13.6 million of revenue in 2019 and recognized $2.5 million related to the milestone in 2020. The $1.4 million allocated to the research activities was recognized as the research services were completed. No revenue was recognized for the year ended December 31, 2021. We recognized $3.5 million and $14.0 million of revenue under this arrangement for the years ended December 31, 2020 and 2019, respectively. There is no deferred revenue as of December 31, 2021. 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 to apply to an identified antibody. Quellis is responsible for all development and commercialization activities. The Company received an equity interest in Quellis and is eligible to receive up to $66.0 million in milestones, which include $6.0 million in development milestones, $30.0 million in regulatory milestones and $30.0 million in sales milestones. In addition, the Company is 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 August 2021, Catabasis effected a reverse stock split of its shares of common stock at a ratio of 1 :6, and in September 2021, Catabasis changed its name to Astria. The Company recorded an impairment charge of $0.8 million for its investment in Astria preferred stock for the year ended December 31, 2021. The Company recognized unrealized gain of $4.5 million related to its equity interest in Astria for the year ended December 31, 2021. There is no deferred revenue as of December 31, 2021 related to this agreement. Bristol-Myers Squibb Company In May 2021, the Company entered into a Technology License Agreement (the BMS Agreement ) with Bristol-Myers Squibb Company (BMS) pursuant to which the Company provided a non-exclusive license to its Xtend technology to extend the half-life of antibodies that specifically bind to SARS-CoV-2. Under the terms of the BMS Agreement, BMS is responsible for all research, development, regulatory and commercial activities for antibodies, and the Company is eligible to receive royalties on net sales of approved products in the low-single digit percentage range. BMS initiated a Phase 2 study with a licensed antibody to treat patients with COVID-19 in the third quarter of 2021. No revenue was recognized for the year ended December 31, 2021. There is no deferred revenue as of December 31, 2021 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 other Collaboration Products, including any new IL-15 programs identified during the joint research collaboration. Genentech and Xencor will jointly collaborate on worldwide development of XmAb306 and potentially other Collaboration Products. The two-year research term expired in March 2021. The Company received a $120.0 million upfront payment and is eligible to receive up to an aggregate of $160.0 million in clinical milestone payments for XmAb306 and up to $180.0 million in clinical milestone payments for each new Collaboration Product. The Company is also eligible to receive 45% share of net profits for sales of XmAb306 and other Collaboration Products, while also sharing in net losses at the same percentage rate. The parties will jointly share in development and commercialization costs for all programs designated as a development program under the Genentech Agreement at the same percentage rate, while Genentech will bear launch costs entirely. The initial 45% profit-cost share percentage is subject to a one-time downward adjustment at the Company’s discretion and convertible to a royalty under certain circumstances. Pursuant to the Genentech Agreement, XmAb306 is designated as a development program and all costs incurred for developing both XmAb306 is being shared with Genentech under the initial cost-sharing percentage. The Company evaluated the Genentech Agreement under the provisions of ASU No. 2014-09, Revenue from Contracts with Customers Collaborative Arrangements The Company identified the following performance obligations under the Genentech Agreement: (i) the license of XmAb306 and (ii) research services during a two-year period, which expired in March 2021, to identify additional IL-15 candidates, each a separate research program and a separate performance obligation. The Company determined that the license and each of the potential research programs are separate performance obligations because they were capable of being distinct in the context of the Genentech Agreement. The license to XmAb306 has standalone functionality as Genentech has exclusive worldwide rights to the program, including the right to sublicense to third parties. Upon the transfer of the license of XmAb306, Genentech could develop and commercialize XmAb306 without further assistance from the Company. The Company determined that the research services for a potential additional IL-15 candidate and research program were separate standalone performance obligations. The Genentech Agreement provided an outline of an integrated research plan for the programs to be conducted by the two companies, and the research activities were separate and distinct from the license to XmAb306. In October 2020, an additional program was declared a Collaboration Program under the Agreement, and the Company completed its performance obligation for that specific research program as the program and licensed rights were transferred to Genentech. The Company determined the standalone selling price of the license to be $114.4 million using the adjusted market assessment approach considering similar collaboration and license agreements and transactions. The standalone selling price for the research activities to be performed during the research term was determined to be $8.5 million using the expected cost approach which was derived from the Company’s experience and information from providing similar research activities to other parties. 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. A total of $2.5 million, $3.5 million, and $2.2 million of revenue related to the research activities was recognized for the years ended December 31, 2021, 2020, and 2019, respectively. For the years ended December 31, 2021, 2020, and 2019, we recognized $2.5 million, $3.5 million, and $113.9 million of income, respectively from the Genentech Agreement. As of December 31, 2021, there is a $2.2 million payable related to cost-sharing development activities during the fourth quarter of 2021. There is no deferred revenue as of December 31, 2021. 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 of $6.0 million and is eligible to receive up to $67.0 million in milestones, which include $10.0 million in development milestones, $27.0 million in regulatory milestones and $30.0 million in 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. The total transaction price is $13.5 million which includes the upfront payment of $6.0 million and the option fee payment of $7.5 million which was contractually due with the exercise of the three options by Gilead. The milestone payments are variable consideration to which the Company applied the “most likely amount” method and concluded at inception of the Gilead 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. No revenue was recognized for the year ended December 31, 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, 2021 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 1,585,000 shares of INmune common stock and an option to acquire additional shares of INmune. The Company also received an option to acquire 108,000 shares of INmune common stock with a designee appointed by us serving on the board of directors of INmune. The option had a six-year term from the date of the INmune Agreement and provided the Company the option to purchase up to 10% of the fully diluted outstanding shares of INmune common stock for $10.0 million. 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 option to INmune for the total consideration of $18.3 million which includes $15.0 million in cash and $3.3 million in additional shares of INmune common stock, which represented an additional 192,533 shares of INmune common stock. The Company recorded a realized gain of $18.3 million according to ASC 860, Transfer and Servicing 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 option to purchase 108,000 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, 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 year ended December 31, 2021, 2020, or 2019. 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, 2021 or 2020. 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 will conduct research and development activities to discover novel CD28 bispecific antibodies for the treatment of prostate cancer. Janssen and Xencor will conduct joint research activities for up to a three-year period 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 of $50.0 million and is eligible to receive up to $662.5 million in milestones which include $161.9 million in development milestones, $240.6 million in regulatory milestones and $260.0 million in 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. We evaluated the Janssen Agreement under ASC 606 and identified the performance obligation under the Agreement to be delivery of CD28 bispecific antibodies to Janssen from the research activities outlined in the research plan. The Company determined that the license to the bispecific antibodies is not a separate performance obligation because it is not capable of being distinct, the license to the antibodies cannot be separated from the underlying antibodies. Janssen will benefit from delivery of the bispecific antibodies upon completion of the research activities. The Company determined that the transaction price of the Janssen Agreement at inception was $50.0 million consisting of the upfront payment. 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 candidate selection option payment is substantive and is a separate performance obligation. 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 the single performance obligation, delivery of CD28 bispecific antibodies to Janssen. The Company will recognize the $50.0 million transaction price as it satisfies its performance obligation to deliver CD28 bispecific antibodies to Janssen. The Company will recognize 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. 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 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 de

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2021
401(k) Plan
401(k) Plan	11. 401(k) Plan We 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

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Polices)	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The Company’s financial statements as of December 31, 2021, 2020, and 2019 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	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	Recent Accounting Pronouncements Pronouncements adopted in 2021 Effective January 1, 2021, the Company adopted ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes Effective January 1, 2021, the Company adopted ASU No. 2020-01, which clarifies that a company should consider observable transactions that require a company to either apply or discontinue the equity method of accounting under Topic 323, Investment – Equity Method and Joint Ventures Investments – Equity Securities Effective January 1, 2021, the Company adopted ASU No. 2020-10, Codification Improvements Pronouncements not yet effective There are accounting standards that have been issued by the Financial Accounting Standards Board (FASB) but are not yet effective. The standards are not expected to have a material impact on our results of operations, financial conditions, or cash flows.
Revenue Recognition	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
Deferred Revenue	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 $37.3 million and $92.6 million at December 31, 2021 and 2020, respectively.
Accounts Receivable	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 allowance for doubtful accounts at December 31, 2021 or 2020, 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 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	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	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, 2021 and 2020, respectively. Accrued interest on marketable debt securities is included in marketable securities’ carrying value. Accrued interest was $0.8 million and $1.4 million at December 31, 2021 and 2020, 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. 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.
Concentrations of Risk	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, 2021 and 2020 approximated $143.2 million and $163.3 million, respectively. We have payables with four service providers that represent 64% of our total payables and with one service provider that represented 49% of our total payables at December 31, 2021 and 2020, respectively. We rely on four 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, 2021 or 2020. We have receivables with two service providers that represent 84% and 88% of our total receivables at December 31, 2021 and 2020, 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, 2021 or 2020.
Fair Value of Financial Instruments	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 Level 1— Level 2— Level 3— 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, 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 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money Market Funds in Cash and Cash Equivalents ​ $ 158,937 ​ $ 158,937 ​ $ — ​ $ — Corporate Securities ​ ​ 119,833 ​ ​ — ​ ​ 119,833 ​ ​ — Government Securities ​ ​ 315,353 ​ ​ — ​ ​ 315,353 ​ ​ — ​ ​ $ 594,123 ​ $ 158,937 ​ $ 435,186 ​ $ — ​ 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, 2021 and 2020, there were no transfers between Level 1 and Level 2.
Property and Equipment	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	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 2021, 2020, and 2019, we abandoned previously capitalized patent and licensing related charges of $0.9 million, $0.5 million, and $0.2 million, respectively. The carrying amount and accumulated amortization of patents, licenses, and other intangibles is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 Patents, definite life $ 13,231 $ 12,038 ​ Patents, pending issuance ​ ​ 8,821 ​ 8,432 ​ Licenses and other amortizable intangible assets ​ ​ 2,474 ​ 2,560 ​ Nonamortizable intangible assets (trademarks) ​ ​ 399 ​ 399 ​ Total gross carrying amount ​ ​ 24,925 ​ 23,429 ​ Accumulated amortization—patents ​ ​ (6,800) ​ (5,791) ​ Accumulated amortization—licenses and other ​ ​ (1,632) ​ (1,661) ​ Total intangible assets, net ​ $ 16,493 ​ $ 15,977 ​ ​ Amortization expense for patents, licenses, and other intangible assets was $1.2 million, $1.1 million, and $0.9 million for the years ended December 31, 2021, 2020, and 2019, respectively. Future amortization expense for patent, licenses, and other intangible assets recorded as of December 31, 2021, and for which amortization has commenced, is as follows: ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, ​ ​ (in thousands) 2022 ​ $ 1,073 ​ 2023 ​ ​ 957 ​ 2024 ​ ​ 770 ​ 2025 ​ ​ 680 ​ 2026 ​ ​ 586 ​ Thereafter ​ ​ 3,207 ​ Total ​ $ 7,273 ​ ​ 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, 2021, the Company has $8.8 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	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, 2021, 2020, or 2019.
Income Taxes	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, 2021 or 2020. 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 tax reform provided for a refund of unused AMT carryforwards for years beginning after December 31, 2017. We received an income tax refund during the years ended December 31, 2020 and 2019 of $0.8 million each year related to our federal AMT carryforwards.
Stock-Based Compensation	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 $37.0 million, $31.6 million, and $31.9 million for the years ended December 31, 2021, 2020, and 2019, respectively.
Net Income (Loss) Per Share	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 and 2019. In 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, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands, except share and per share data) Basic ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common stockholders for basic net income (loss) per share ​ $ 82,631 ​ $ (69,333) ​ $ 26,875 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding ​ ​ 58,379,641 ​ 57,212,737 ​ 56,531,439 ​ Basic net income (loss) per common share ​ $ 1.42 ​ $ (1.21) ​ $ 0.48 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common stockholders for diluted net income (loss) per share ​ $ 82,631 ​ $ (69,333) ​ $ 26,875 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding used in computing basic net income (loss) per common share ​ ​ 58,379,641 ​ 57,212,737 ​ 56,531,439 ​ Dilutive effect of employee stock options, RSUs, and ESPP ​ ​ 2,115,814 ​ — ​ 1,936,441 ​ Weighted-average number of common shares outstanding used in computing diluted net income (loss) per common share ​ ​ 60,495,455 ​ 57,212,737 ​ 58,467,880 ​ Diluted net income (loss) per common share ​ $ 1.37 ​ $ (1.21) ​ $ 0.46 ​ ​ 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. For the year ended December 31, 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, 2019, we excluded 1,022,623 shares of options and RSUs from the calculation because the inclusion of such shares would have had an anti-dilutive effect.
Segment Reporting	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 .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies
Schedule of assets recorded at fair value	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, 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 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money Market Funds in Cash and Cash Equivalents ​ $ 158,937 ​ $ 158,937 ​ $ — ​ $ — Corporate Securities ​ ​ 119,833 ​ ​ — ​ ​ 119,833 ​ ​ — Government Securities ​ ​ 315,353 ​ ​ — ​ ​ 315,353 ​ ​ — ​ ​ $ 594,123 ​ $ 158,937 ​ $ 435,186 ​ $ —
Schedule of useful lives by asset category	​ ​ ​ ​ ​ ​ ​ 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	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 Patents, definite life $ 13,231 $ 12,038 ​ Patents, pending issuance ​ ​ 8,821 ​ 8,432 ​ Licenses and other amortizable intangible assets ​ ​ 2,474 ​ 2,560 ​ Nonamortizable intangible assets (trademarks) ​ ​ 399 ​ 399 ​ Total gross carrying amount ​ ​ 24,925 ​ 23,429 ​ Accumulated amortization—patents ​ ​ (6,800) ​ (5,791) ​ Accumulated amortization—licenses and other ​ ​ (1,632) ​ (1,661) ​ Total intangible assets, net ​ $ 16,493 ​ $ 15,977 ​
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, ​ ​ 2021 ​ 2020 Patents, definite life $ 13,231 $ 12,038 ​ Patents, pending issuance ​ ​ 8,821 ​ 8,432 ​ Licenses and other amortizable intangible assets ​ ​ 2,474 ​ 2,560 ​ Nonamortizable intangible assets (trademarks) ​ ​ 399 ​ 399 ​ Total gross carrying amount ​ ​ 24,925 ​ 23,429 ​ Accumulated amortization—patents ​ ​ (6,800) ​ (5,791) ​ Accumulated amortization—licenses and other ​ ​ (1,632) ​ (1,661) ​ Total intangible assets, net ​ $ 16,493 ​ $ 15,977 ​
Future amortization expense for patents, licenses, and other intangible assets	​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, ​ ​ (in thousands) 2022 ​ $ 1,073 ​ 2023 ​ ​ 957 ​ 2024 ​ ​ 770 ​ 2025 ​ ​ 680 ​ 2026 ​ ​ 586 ​ Thereafter ​ ​ 3,207 ​ Total ​ $ 7,273 ​
Schedule of basic and diluted net income (loss) per common share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands, except share and per share data) Basic ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common stockholders for basic net income (loss) per share ​ $ 82,631 ​ $ (69,333) ​ $ 26,875 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding ​ ​ 58,379,641 ​ 57,212,737 ​ 56,531,439 ​ Basic net income (loss) per common share ​ $ 1.42 ​ $ (1.21) ​ $ 0.48 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common stockholders for diluted net income (loss) per share ​ $ 82,631 ​ $ (69,333) ​ $ 26,875 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding used in computing basic net income (loss) per common share ​ ​ 58,379,641 ​ 57,212,737 ​ 56,531,439 ​ Dilutive effect of employee stock options, RSUs, and ESPP ​ ​ 2,115,814 ​ — ​ 1,936,441 ​ Weighted-average number of common shares outstanding used in computing diluted net income (loss) per common share ​ ​ 60,495,455 ​ 57,212,737 ​ 58,467,880 ​ Diluted net income (loss) per common share ​ $ 1.37 ​ $ (1.21) ​ $ 0.46 ​

Marketable Debt and Equity Se_2

Marketable Debt and Equity Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Marketable Debt and Equity Securities
Schedule of marketable securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized Unrealized ​ Unrealized ​ ​ ​ Cost ​ Gains ​ 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized Unrealized ​ Unrealized ​ ​ ​ Cost ​ Gains ​ Losses ​ Fair Value (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money Market Funds ​ $ 158,937 ​ $ — ​ $ — ​ $ 158,937 Corporate Securities ​ ​ 119,782 ​ ​ 57 ​ ​ (6) ​ ​ 119,833 Government Securities ​ ​ 315,319 ​ ​ 37 ​ ​ (3) ​ ​ 315,353 ​ ​ $ 594,038 ​ $ 94 ​ $ (9) ​ $ 594,123 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reported as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 158,937 Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 435,186 Total investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 594,123
Schedule of maturities of marketable securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Estimated ​ ​ Cost ​ Fair Value (in thousands) ​ ​ ​ ​ ​ ​ Mature in one year or less ​ $ 153,871 ​ $ 153,767 Mature within two years ​ ​ 301,861 ​ ​ 300,465 ​ ​ $ 455,732 ​ $ 454,232
Schedule of unrealized losses on available-for-sale investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Less than 12 months ​ 12 months or greater ​ ​ ​ Fair value ​ ​ Unrealized losses ​ ​ Fair value ​ ​ Unrealized losses (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate Securities ​ $ 15,843 ​ $ (6) ​ $ — ​ $ — Government Securities ​ ​ 40,802 ​ ​ (3) ​ ​ — ​ ​ — ​ ​ $ 56,645 ​ $ (9) ​ $ — ​ $ —
Schedule of equity securities with readily determinable fair value	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, 2021 and 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Fair Value ​ ​ December 31, 2021 ​ December 31, 2020 Astria Common Stock ​ $ 3,449 ​ $ — INmune Common Stock ​ ​ 19,233 ​ ​ — Viridian Common Stock ​ ​ 14,178 ​ ​ 5,303 ​ ​ $ 36,860 ​ $ 5,303
Schedule of equity securities without readily determinable fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Value Carrying Value ​ ​ December 31, 2021 ​ December 31, 2020 Astria Preferred Stock ​ $ 312 ​ $ — Zenas Preferred Stock ​ ​ 30,950 ​ ​ 16,071 ​ ​ $ 31,262 ​ $ 16,071
Schedule of net gains and losses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ 2020 ​ ​ ​ Net gains recognized on equity securities ​ $ 39,289 ​ $ 105 Less: net gains recognized on equity securities redeemed ​ ​ 18,301 ​ 801 Unrealized gain (losses) recognized on equity securities ​ $ 20,988 ​ $ (696)

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2021
Property and Equipment
Schedule of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Computers, software and equipment $ 41,955 $ 31,229 ​ Furniture and fixtures ​ ​ 539 ​ 527 ​ Leasehold and tenant improvements ​ ​ 8,574 ​ 6,957 ​ Total gross carrying amount ​ ​ 51,068 ​ 38,713 ​ Less accumulated depreciation and amortization ​ (22,828) ​ (17,031) ​ Total property and equipment, net ​ $ 28,240 ​ $ 21,682 ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Taxes
Reconciliation of the federal statutory income tax rate to our effective income tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 Federal statutory income tax $ 17,352 $ (14,559) $ 5,709 ​ State and local income taxes ​ ​ 783 ​ ​ (4,659) ​ 2,549 ​ Research and development credit ​ (10,492) ​ (9,669) ​ (6,747) ​ Stock-based compensation ​ ​ 2,424 ​ ​ 529 ​ ​ 1,927 ​ State credit ​ ​ — ​ ​ — ​ ​ 1,725 ​ Other ​ ​ 95 ​ ​ 56 ​ (301) ​ Change in state rate ​ ​ 2,599 ​ ​ — ​ ​ — ​ Net change in valuation allowance ​ ​ (12,761) ​ ​ 28,302 ​ (4,550) ​ Income tax provision ​ $ — ​ $ — ​ $ 312 ​
Schedule of tax effect of temporary differences that give rise to a significant portion of the deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 2020 ​ Deferred income tax assets ​ ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 46,629 ​ $ 56,182 ​ Research credits ​ ​ 48,128 ​ 38,047 ​ Unrealized loss on securities ​ ​ 327 ​ 195 ​ Capitalized lease assets ​ ​ 489 ​ ​ 288 ​ Accrued compensation ​ ​ 9,207 ​ 8,464 ​ Deferred revenue ​ ​ — ​ 11,925 ​ Gross deferred income tax assets ​ ​ 104,780 ​ 115,101 ​ Valuation allowance ​ (93,580) ​ (105,995) ​ Net deferred income tax assets ​ ​ 11,200 ​ 9,106 ​ Deferred income tax liabilities ​ ​ ​ ​ ​ ​ ​ Patent costs ​ (3,416) ​ (4,219) ​ Equity investment ​ ​ (3,508) ​ ​ (4,497) ​ Licensing costs ​ (151) ​ (194) ​ Capitalized legal costs ​ (13) ​ (21) ​ Depreciation ​ ​ (288) ​ ​ (151) ​ Unrealized gain on securities ​ ​ (3,824) ​ ​ (24) ​ Gross deferred income tax liabilities ​ (11,200) ​ (9,106) ​ Net deferred income tax asset ​ $ — ​ $ — ​

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Stock-Based Compensation
Schedule of total employee, director and non-employee stock-based compensation expense recognized	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands) ​ 2021 ​ 2020 ​ 2019 General and administrative $ 12,813 $ 10,769 $ 8,854 ​ Research and development ​ ​ 24,162 ​ ​ 20,850 ​ 22,997 ​ ​ ​ $ 36,975 ​ $ 31,619 ​ $ 31,851 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ (in thousands) ​ 2021 ​ 2020 ​ 2019 ​ Stock options $ 27,909 $ 26,045 $ 30,502 ​ ESPP ​ ​ 992 ​ 804 ​ 687 ​ RSUs ​ ​ 8,074 ​ 4,770 ​ 662 ​ ​ ​ $ 36,975 ​ $ 31,619 ​ $ 31,851 ​
Schedule of stock options outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 Exercisable options ​ 5,576,430 ​ 4,668,179 ​ 3,950,965 ​ Weighted average exercise price per share of exercisable options ​ $ 24.15 ​ $ 21.75 ​ $ 17.79 ​ Weighted average grant date fair value per share of options granted during the year ​ $ 21.65 ​ $ 16.96 ​ $ 20.74 ​ Options available for future grants ​ 3,597,371 ​ 3,346,092 ​ 3,975,160 ​ Weighted average remaining contractual life ​ 6.65 ​ 7.00 ​ 7.32 ​
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ ​ ​ ​ ​ ​ ​ Exercise ​ Contractual ​ Aggregate ​ ​ Number of ​ Price ​ Term ​ Intrinsic Value ​ ​ Shares ​ (Per Share) (1) ​ (in years) ​ (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 ​ As of December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options vested and expected to vest 8,676,329 ​ $ 29.11 6.65 ​ $ 100,057 ​ Exercisable 5,576,430 ​ $ 24.15 5.53 ​ $ 89,287 ​
Schedule of stock options outstanding and exercisable by exercise price	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock Options Outstanding ​ Stock Options Exercisable ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Remaining Weighted- ​ Weighted- Range of ​ ​ ​ Contractual ​ Average ​ ​ ​ Average Exercise ​ Number of ​ Term ​ Exercise Price ​ Number of ​ Exercise Price Prices ​ Shares ​ (in years) ​ Per Share ​ Shares ​ Per Share $4.25 – $10.28 151,488 1.68 ​ $ 4.29 151,488 ​ $ 4.29 ​ $10.52 – $15.78 1,508,709 3.33 ​ $ 13.15 1,507,724 ​ $ 13.15 ​ $15.91 – $23.87 1,777,216 5.52 ​ $ 22.77 1,756,016 ​ $ 22.76 ​ $23.96 – $35.94 ​ 2,312,270 ​ 7.91 ​ $ 32.08 ​ 1,168,530 ​ $ 31.65 ​ $35.99 – $53.99 ​ 2,926,646 ​ 8.31 ​ $ 40.12 ​ 992,672 ​ $ 37.52 ​ ​ 8,676,329 6.65 ​ $ 29.11 5,576,430 ​ $ 24.15 ​
Schedule of weighted average assumptions used for estimation of fair value of stock options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options ​ ​ 2021 2020 2019 Common stock fair value per share ​ $ 30.65 - 49.47 ​ $ 20.69 - 45.91 ​ $ 29.96 - 44.19 ​ Expected volatility ​ 53.91% - 56.82% ​ 52.93% - 58.95% ​ 60.67% - 61.33% ​ Risk-free interest rate ​ 0.47% - 1.33% ​ 0.29% - 1.71% ​ 1.37% - 2.60% ​ Expected dividend yield ​ — ​ — ​ — ​ Expected term (in years) ​ 6.00 - 7.65 ​ 5.23 - 7.65 ​ 5.23 - 6.59 ​
Schedule of weighted average assumptions used for estimation of fair value of ESPP	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ESPP ​ ​ 2021 2020 2019 ​ Expected term (years) 0.5 - 2.0 0.5 - 2.0 0.5 - 2.0 ​ Expected volatility ​ 46.08% - 66.37% ​ 50.77% - 66.37% ​ 50.77% - 71.37% ​ Risk-free interest rate 0.04% - 1.65% ​ 0.09% - 1.65% ​ 1.47% - 2.70% ​ Expected dividend yield ​ — ​ — ​ — ​
Summary of restricted stock unity activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ Number of ​ Fair Value ​ ​ Shares ​ (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

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases
Schedule of operating lease liabilities maturities	The following table reconciles the undiscounted cash flows for the operating leases at December 31, 2021 to the operating lease liabilities recorded on the balance sheet (in thousands): ​ ​ ​ ​ Years ending December 31, ​ ​ 2022 ​ $ 2,097 2023 ​ ​ 5,566 2024 ​ ​ 5,713 2025 ​ ​ 5,817 2026 ​ ​ 5,279 Thereafter ​ ​ 52,117 Total undiscounted lease payments ​ ​ 76,589 Less: Tenant allowance ​ ​ (17,032) Less: Imputed interest ​ ​ (25,588) Present value of lease payments ​ $ 33,969 ​ ​ ​ ​ Lease liabilities - long-term ​ $ 33,969
Summary of lease costs and cash disclosures	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 2020 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating lease cost ​ $ 4,342 ​ $ 2,503 ​ $ 2,596 Variable lease cost ​ ​ 58 ​ ​ 150 ​ ​ 80 Total lease costs ​ $ 4,400 ​ $ 2,653 ​ $ 2,676 Cash paid for amounts included in ​ ​ ​ ​ ​ ​ ​ ​ ​ the measurement of lease liabilities ​ $ 2,773 ​ $ 2,233 ​ $ 1,929 Weighted-average remaining lease term ​ ​ ​ ​ ​ ​ ​ ​ ​ —operating leases (in years) ​ ​ 12.3 ​ ​ 7.4 ​ ​ 5.5 Weighted-average discount rate ​ ​ ​ ​ ​ ​ ​ ​ ​ —operating leases ​ ​ 5.8% ​ ​ 5.5% ​ ​ 5.5%

Collaboration and Licensing A_2

Collaboration and Licensing Agreements (Tables)	12 Months Ended
	Dec. 31, 2021
Collaboration and Licensing Agreements
Schedule of revenue by licensees	The $275.1 million, $122.7 million, and $156.7 million of revenue recorded for the years ended December 31, 2021, 2020, and 2019, respectively, were earned principally from the following licensees (in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 Aimmune $ — $ 9.6 $ — ​ Alexion ​ ​ 22.2 ​ 26.2 ​ 13.0 ​ Amgen ​ ​ — ​ — ​ 5.0 ​ Astellas ​ ​ — ​ 3.5 ​ 14.0 ​ Genentech ​ ​ 2.5 ​ 3.5 ​ 113.9 ​ Gilead ​ ​ — ​ 13.5 ​ — ​ Janssen ​ ​ 113.8 ​ ​ — ​ ​ — ​ MorphoSys ​ ​ 18.4 ​ 39.0 ​ — ​ Novartis ​ ​ 43.1 ​ — ​ 10.0 ​ Omeros ​ ​ — ​ 5.0 ​ — ​ Vir ​ ​ 52.7 ​ 0.3 ​ 0.8 ​ Viridian ​ ​ 7.5 ​ 6.0 ​ — ​ Zenas ​ ​ 14.9 ​ 16.1 ​ — ​ Total ​ $ 275.1 ​ $ 122.7 ​ $ 156.7 ​
Schedule of disaggregation of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 Research collaboration $ 93.0 $ 4.5 $ 16.3 Milestone ​ ​ 21.0 ​ 50.2 ​ 23.2 Licensing ​ ​ 80.8 ​ 50.2 ​ 112.2 Royalties ​ ​ 80.3 ​ 17.8 ​ 5.0 Total ​ $ 275.1 ​ $ 122.7 ​ $ 156.7

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Concentration Risk (Details)	12 Months Ended
	Dec. 31, 2021USD ($)item	Dec. 31, 2020USD ($)item
Concentrations of risk
Deferred revenue	$ 37,300,000	$ 92,600,000
Accrued interest	800,000	1,400,000
Impairment loss or recoveries	0	0
Amounts on deposit in excess of federally insured limits approximately	$ 143,200,000	$ 163,300,000
Minimum
Concentrations of risk
Collection period	30 days
Maximum
Concentrations of risk
Collection period	60 days
Accounts receivable | Customers | Major Customers
Concentrations of risk
Concentration risk percentage	84.00%	88.00%
Accounts receivable | Service providers
Concentrations of risk
Number of service providers | item	2	2
Payables | Service providers
Concentrations of risk
Number of service providers | item	4	1
Number of critical suppliers | item	4
Payables | Service providers | Major Vendors
Concentrations of risk
Concentration risk percentage	64.00%	49.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value of Financial Instruments
Money Market Funds	$ 143,480	$ 163,544
Marketable Securities	454,232
Equity Securities with Readily Determinable Fair Value	36,860	5,303
Money Market Funds
Fair Value of Financial Instruments
Money Market Funds	123,892	158,937
Corporate Securities
Fair Value of Financial Instruments
Marketable Securities	144,418	119,833
Government Securities
Fair Value of Financial Instruments
Marketable Securities	309,814	315,353
Fair Value, Measurements, Recurring
Fair Value of Financial Instruments
Total Fair Value	578,124	594,123
Fair Value, Measurements, Recurring | Money Market Funds
Fair Value of Financial Instruments
Money Market Funds	123,892	158,937
Fair Value, Measurements, Recurring | Corporate Securities
Fair Value of Financial Instruments
Marketable Securities	144,418	119,833
Fair Value, Measurements, Recurring | Government Securities
Fair Value of Financial Instruments
Marketable Securities	309,814	315,353
Level 1 | Fair Value, Measurements, Recurring
Fair Value of Financial Instruments
Total Fair Value	123,892	158,937
Level 1 | Fair Value, Measurements, Recurring | Money Market Funds
Fair Value of Financial Instruments
Money Market Funds	123,892	158,937
Level 2 | Fair Value, Measurements, Recurring
Fair Value of Financial Instruments
Total Fair Value	454,232	435,186
Level 2 | Fair Value, Measurements, Recurring | Corporate Securities
Fair Value of Financial Instruments
Marketable Securities	144,418	119,833
Level 2 | Fair Value, Measurements, Recurring | Government Securities
Fair Value of Financial Instruments
Marketable Securities	$ 309,814	$ 315,353

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Property, Plant, and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
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 Accoun_7

Summary of Significant Accounting Policies - Intangibles (Details)	12 Months Ended
	Dec. 31, 2021USD ($)item	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2022	$ 1,073,000
2023	957,000
2024	770,000
2025	680,000
2026	586,000
Thereafter	3,207,000
Total	$ 7,273,000
Number of primary criteria to determine capitalization of patent | item	3
Impairment loss or recoveries	$ 0	$ 0
Total gross carrying amount	24,925,000	23,429,000
Total intangible assets, net	16,493,000	15,977,000
Abandonment of capitalized intangible assets	934,000	535,000	$ 221,000
Amortization expense for patents, licenses, and other intangible assets	1,200,000	1,100,000	$ 900,000
Nonamortizable intangible assets (trademarks)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Nonamortizable intangible assets (trademarks)	$ 399,000	399,000
Acquired licenses | Minimum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated economic life	1 year
Acquired licenses | Maximum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated economic life	18 years
Patents
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Accumulated amortization	$ (6,800,000)	(5,791,000)
Patents | Minimum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated economic life	3 years
Patents | Maximum
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated economic life	27 years
Patents, definite life
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortizable intangible assets	$ 13,231,000	12,038,000
Patents, pending issuance
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortizable intangible assets	8,821,000	8,432,000
Licenses and other amortizable intangible assets
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortizable intangible assets	2,474,000	2,560,000
Accumulated amortization	$ (1,632,000)	$ (1,661,000)

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
US corporate tax rate	21.00%	21.00%	21.00%	21.00%	35.00%
Federal
Income Taxes [Line Items]
Income tax refund		$ 0.8	$ 0.8

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock-Based Compensation
Stock-based compensation expense	$ 37,000	$ 31,600	$ 31,900
Net Loss Per Share
Securities excluded in calculation of EPS	1,196,268		1,022,623
Basic numerator:
Net income (loss) attributable to common stockholders	$ 82,631	$ (69,333)	$ 26,875
Denominator:
Weighted average common shares outstanding, basic	58,379,641	57,212,737	56,531,439
Net income (loss) per common share, basic (in dollars per share)	$ 1.42	$ (1.21)	$ 0.48
Diluted numerator:
Net income (loss) attributable to common stockholders for diluted net income (loss) per share	$ 82,631	$ (69,333)	$ 26,875
Denominator
Weighted average common shares outstanding, basic	58,379,641	57,212,737	56,531,439
Dilutive effect of employee stock options and ESPP	2,115,814		1,936,441
Weighted average common shares outstanding, diluted	60,495,455	57,212,737	58,467,880
Net income (loss) per common share, diluted (in dollars per share)	$ 1.37	$ (1.21)	$ 0.46

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Segments (Details)	12 Months Ended
	Dec. 31, 2021segment
Segment Reporting
Number of Operating Segments	1

Marketable Debt and Equity Se_3

Marketable Debt and Equity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities
Cash and cash equivalents	$ 143,480	$ 163,544
Investments, amortized cost	579,624	594,038
Investments	578,124	594,123
Total amortized cost	455,732
Gross unrealized gains	1	94
Gross unrealized losses	(1,501)	(9)
Marketable Securities	454,232
Marketable securities
Schedule of Available-for-sale Securities
Marketable Securities	454,232	435,186
Money Market Funds
Schedule of Available-for-sale Securities
Cash and cash equivalents	123,892	158,937
Corporate Securities
Schedule of Available-for-sale Securities
Total amortized cost	144,584	119,782
Gross unrealized gains		57
Gross unrealized losses	(166)	(6)
Marketable Securities	144,418	119,833
Government Securities
Schedule of Available-for-sale Securities
Total amortized cost	311,148	315,319
Gross unrealized gains	1	37
Gross unrealized losses	(1,335)	(3)
Marketable Securities	309,814	315,353
Cash and Cash Equivalents
Schedule of Available-for-sale Securities
Cash and cash equivalents	$ 123,892	$ 158,937

Marketable Debt and Equity Se_4

Marketable Debt and Equity Securities - Maturities (Details) $ in Thousands	Dec. 31, 2021USD ($)
Amortized Cost
Maturing in one year or less	$ 153,871
Maturing within two years	301,861
Total amortized cost	455,732
Estimate Fair Value
Maturing in one year or less	153,767
Maturing within two years	300,465
Total estimated fair value	$ 454,232

Marketable Debt and Equity Se_5

Marketable Debt and Equity Securities - Unrealized losses (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair value
Fair value, less than 12 months	$ 90,246	$ 56,645
Fair value, 12 months or greater	300,465
Unrealized losses
Unrealized losses, Less than 12 months	(105)	(9)
Unrealized losses, 12 months or greater	(1,396)
Corporate Securities
Fair value
Fair value, less than 12 months	50,337	15,843
Fair value, 12 months or greater	45,872
Unrealized losses
Unrealized losses, Less than 12 months	(51)	(6)
Unrealized losses, 12 months or greater	(115)
Government Securities
Fair value
Fair value, less than 12 months	39,909	40,802
Fair value, 12 months or greater	254,593
Unrealized losses
Unrealized losses, Less than 12 months	(54)	$ (3)
Unrealized losses, 12 months or greater	$ (1,281)

Marketable Debt and Equity Se_6

Marketable Debt and Equity Securities - Equity Securities with Readily Determinable Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Equity Securities
Equity Securities with Readily Determinable Fair Value	$ 36,860	$ 5,303
Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	36,860	5,303
Astria/Catabasis | Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	3,449
INmune | Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	19,233
MiRagen/Viridian | Common Stock
Equity Securities
Equity Securities with Readily Determinable Fair Value	$ 14,178	$ 5,303

Marketable Debt and Equity Se_7

Marketable Debt and Equity Securities - Equity Securities without Readily Determinable Fair Value (Details) - Preferred Stock - USD ($) $ in Thousands	Dec. 31, 2021	Jul. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Equity securities without readily determinable fair value
Equity Securities without Readily Determinable Fair Value	$ 31,262			$ 16,071
Astria/Catabasis
Equity securities without readily determinable fair value
Equity Securities without Readily Determinable Fair Value	312	$ 1,100	$ 12,100
Zenas Bio Pharma Limited
Equity securities without readily determinable fair value
Equity Securities without Readily Determinable Fair Value	$ 30,950			$ 16,071

Marketable Debt and Equity Se_8

Marketable Debt and Equity Securities - Equity Securities Transactions (Details) $ in Thousands	1 Months Ended							12 Months Ended
	Dec. 31, 2021USD ($)shares	Sep. 30, 2021USD ($)shares	Aug. 31, 2021	Jul. 31, 2021USD ($)shares	Jun. 30, 2021USD ($)shares	Dec. 31, 2020USD ($)shares	Oct. 31, 2017USD ($)shares	Dec. 31, 2021USD ($)shares	Dec. 31, 2020USD ($)	Dec. 31, 2017shares
Equity Securities
Net gains recognized on equity securities | $								$ 39,289	$ 105
Impairment | $								762
Preferred Stock
Equity Securities
Equity Securities without Readily Determinable Fair Value | $	$ 31,262					$ 16,071		$ 31,262	$ 16,071
Astria/Catabasis | Common Stock
Equity Securities
Shares received in noncash transaction					259,206
Shares issued upon conversion					3,580,539
Reverse stock split ratio			0.166
Number of shares								3,839,745
Astria/Catabasis | Preferred Stock
Equity Securities
Shares received in noncash transaction				347	3,928
Number of preferred stock converted (in shares)					3,581
Equity Securities without Readily Determinable Fair Value | $	$ 312			$ 1,100	$ 12,100			$ 312
Impairment | $								$ 800
Technology License Agreement | MiRagen/Viridian
Equity Securities
Shares received in noncash transaction	394,737					322,407
Purchase amount of share options or equity in noncash transaction | $	$ 7,500					$ 6,000
Technology License Agreement | MiRagen/Viridian | Common Stock
Equity Securities
Shares received in noncash transaction	394,737					322,407
Technology License Agreement | Astria/Catabasis | Common Stock
Equity Securities
Reverse stock split ratio			0.166
License Agreement | INmune
Equity Securities
Shares received in noncash transaction							1,585,000
Purchase amount of share options or equity in noncash transaction | $							$ 10,000
Number of shares					192,533
Cash consideration on sale of option | $					$ 15,000
License Agreement | INmune | Common Stock
Equity Securities
Shares received in noncash transaction										1,585,000
Additional equity interests (as a percentage)					10.00%					10.00%
Option to acquire shares							108,000			108,000
Shares issued upon conversion					192,533
Purchase amount of share options or equity in noncash transaction | $		$ 800
Net gains recognized on equity securities | $		$ 900
Number of shares		108,000						1,885,533
Cash consideration on sale of option | $					$ 15,000

Marketable Debt and Equity Se_9

Marketable Debt and Equity Securities - Net gains and losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Marketable Debt and Equity Securities
Net gains recognized on equity securities	$ 39,289	$ 105
Less: net gains recognized on equity securities redeemed	18,301	801
Unrealized gains (losses) recognized on equity securities	$ 20,988	$ (696)

Sale of Additional Common Sto_2

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

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property and equipment
Property and equipment, gross	$ 51,068	$ 38,713
Less accumulated depreciation and amortization	(22,828)	(17,031)
Property and equipment, net	28,240	21,682
Depreciation and amortization expense	6,300	4,700	$ 3,400
Computers, software and equipment
Property and equipment
Property and equipment, gross	41,955	31,229
Furniture and fixtures
Property and equipment
Property and equipment, gross	539	527
Leasehold and tenant improvements
Property and equipment
Property and equipment, gross	$ 8,574	$ 6,957

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of federal statutory income tax to effective income tax
Federal statutory income tax	$ 17,352	$ (14,559)	$ 5,709
State and local income taxes	783	(4,659)	2,549
Research and development credit	(10,492)	(9,669)	(6,747)
Stock based compensation	2,424	529	1,927
State credit			1,725
Other	95	56	(301)
Change in state rate	2,599
Net change in valuation allowance	(12,761)	28,302	(4,550)
Income tax provision	$ 0	$ 0	$ 312

Income Taxes - Deferred tax ass

Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred income tax assets
Net operating loss carryforwards	$ 46,629	$ 56,182
Research credits	48,128	38,047
Unrealized loss on securities	327	195
Capitalized lease assets	489	288
Accrued compensation	9,207	8,464
Deferred revenue		11,925
Gross deferred income tax assets	104,780	115,101
Valuation allowance	(93,580)	(105,995)
Net deferred income tax assets	11,200	9,106
Deferred income tax liabilities
Patent costs	(3,416)	(4,219)
Equity investment	(3,508)	(4,497)
Licensing costs	(151)	(194)
Capitalized legal costs	(13)	(21)
Depreciation	(288)	(151)
Unrealized gain on securities	(3,824)	(24)
Gross deferred income tax liabilities	$ (11,200)	$ (9,106)

Income Taxes - TCJA and Net ope

Income Taxes - TCJA and Net operating loss carryforwards (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Increase (decrease) in deferred tax asset valuation allowance	$ (12.4)
Federal
Income Taxes [Line Items]
Income tax refund		$ 0.8	$ 0.8
Cumulative net operating loss carryforwards	168.2
Tax credit carryforwards	$ 34
Tax credits expiring in next five years			$ 0.5
Period to use tax credit carryforward	4 years
State
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	$ 161.6
Tax credit carryforwards	17.8
Years Prior to 2018 | Federal
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	63.9
Years After 2018 | Federal
Income Taxes [Line Items]
Cumulative net operating loss carryforwards	$ 104.3

Stock-Based Compensation - Plan

Stock-Based Compensation - Plan details (Details)	Jan. 01, 2021shares	Jan. 01, 2014shares	Dec. 31, 2021item$ / sharesshares	Dec. 31, 2020$ / sharesshares	Dec. 31, 2019$ / sharesshares	Dec. 31, 2018shares	Dec. 31, 2017shares	Dec. 31, 2016shares	Dec. 31, 2015shares	Dec. 31, 2021item$ / sharesshares	Nov. 30, 2013shares
Stock options
Stock-based compensation
Total number of shares of common stock available for issuance			3,597,371	3,346,092	3,975,160					3,597,371
Options granted (in shares)			1,827,234	1,679,324
Information with respect to stock options outstanding
Exercisable options (in shares)			5,576,430	4,668,179	3,950,965					5,576,430
Weighted-average exercise price per share of exercisable options (in dollars per share) | $ / shares			$ 24.15	$ 21.75	$ 17.79					$ 24.15
Weighted average grant date fair value per share of options granted during the year (in dollars per share) | $ / shares			$ 21.65	$ 16.96	$ 20.74
Weighted-average remaining contractual life			6 years 7 months 24 days	7 years	7 years 3 months 25 days
Employee stock purchase plan
Stock-based compensation
Total number of shares of common stock available for issuance											581,286
Initial term of plan			2 years
Second term of plan			2 years
Number of six month purchase periods | item			4							4
Purchase period			6 months
Increase in shares of common stock available for issuance (in shares)		313,545	0	0	0	0	0	0	0
Awards issued under the plan (in shares)										529,852
Employee stock purchase plan | Minimum
Stock-based compensation
Percentage of compensation that employees may withhold to purchase stock at a discount			1.00%							1.00%
Employee stock purchase plan | Maximum
Stock-based compensation
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 percentage increase in shares of common stock available for issuance			1.00%
Annual increase in shares of common stock available for issuance (in shares)			621,814
Restricted stock units
Stock-based compensation
Restricted stock granted (in shares)			670,700	348,288
The 2010 Plan
Stock-based compensation
Total number of shares of common stock available for issuance			0							0
The 2013 Plan
Stock-based compensation
Total number of shares of common stock available for issuance			13,122,238							13,122,238
Annual percentage increase in shares of common stock available for issuance			4.00%
Increase in shares of common stock available for issuance (in shares)	2,314,937
Awards issued under the plan (in shares)										12,400,073
The 2013 Plan | Restricted stock units
Stock-based compensation
Restricted stock granted (in shares)										1,124,487
The 2013 Plan | Restricted stock units | Minimum
Stock-based compensation
Vesting period			2 years
The 2013 Plan | Restricted stock units | Maximum
Stock-based compensation
Vesting period			3 years

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation
Total employee, director and non-employee stock-based compensation expense	$ 36,975	$ 31,619	$ 31,851
Options to purchase common stock
Stock-based compensation
Total employee, director and non-employee stock-based compensation expense	27,909	26,045	30,502
Employee stock purchase plan
Stock-based compensation
Total employee, director and non-employee stock-based compensation expense	992	804	687
Restricted stock units
Stock-based compensation
Total employee, director and non-employee stock-based compensation expense	8,074	4,770	662
General and administrative
Stock-based compensation
Total employee, director and non-employee stock-based compensation expense	12,813	10,769	8,854
Research and development
Stock-based compensation
Total employee, director and non-employee stock-based compensation expense	$ 24,162	$ 20,850	$ 22,997

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock option activity, Number of Shares
Balance at the beginning of the period (in shares)	7,751,789	7,174,319
Options granted (in shares)	1,827,234	1,679,324
Options forfeited (in shares)	(382,454)	(243,384)
Options exercised (in shares)	(520,240)	(858,470)
Balance at the end of the period (in shares)	8,676,329	7,751,789	7,174,319
Options vested and expected to vest (in shares)	8,676,329
Exercisable (in shares)	5,576,430	4,668,179	3,950,965
Weighted Average Exercise Price (Per Share)
Balance at the beginning of the period (in dollars per share)	$ 26.23	$ 24.03
Options granted (in dollars per share)	41.22	33.08
Options forfeited (in dollars per share)	36.15	32.93
Options exercised (in dollars per share)	23.61	19.36
Balance at the end of the period (in dollars per share)	29.11	26.23	$ 24.03
Options vested and expected to vest (in dollars per share)	29.11
Exercisable (in dollars per share)	$ 24.15	$ 21.75	$ 17.79
Additional information
Weighted-Average Remaining Contractual Term, Balance outstanding	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 7 months 24 days
Weighted-Average Remaining Contractual Term, Exercisable	5 years 6 months 10 days
Aggregate Intrinsic Value, Balance outstanding	$ 100,057	$ 134,941	$ 79,116
Aggregate Intrinsic Value, Options vested and expected to vest	100,057
Aggregate Intrinsic Value, Exercisable	89,287
Intrinsic value of options exercised	$ 9,200	$ 16,300	$ 11,500

Stock-Based Compensation - Opti

Stock-Based Compensation - Options by exercise price (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Stock options outstanding and exercisable by exercise price
Stock Options Outstanding, Number of Shares | shares	8,676,329
Stock Options Outstanding, Remaining Contractual Term	6 years 7 months 24 days
Stock Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 29.11
Stock Options Exercisable, Number of Shares | shares	5,576,430
Stock Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 24.15
$4.25 - $10.28
Stock options outstanding and exercisable by exercise price
Range of Exercise Prices, lower limit (in dollars per share)	4.25
Range of Exercise Prices, upper limit (in dollars per share)	$ 10.28
Stock Options Outstanding, Number of Shares | shares	151,488
Stock Options Outstanding, Remaining Contractual Term	1 year 8 months 4 days
Stock Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 4.29
Stock Options Exercisable, Number of Shares | shares	151,488
Stock Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 4.29
$10.52 - $15.78
Stock options outstanding and exercisable by exercise price
Range of Exercise Prices, lower limit (in dollars per share)	10.52
Range of Exercise Prices, upper limit (in dollars per share)	$ 15.78
Stock Options Outstanding, Number of Shares | shares	1,508,709
Stock Options Outstanding, Remaining Contractual Term	3 years 3 months 29 days
Stock Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 13.15
Stock Options Exercisable, Number of Shares | shares	1,507,724
Stock Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 13.15
$15.91 - $23.87
Stock options outstanding and exercisable by exercise price
Range of Exercise Prices, lower limit (in dollars per share)	15.91
Range of Exercise Prices, upper limit (in dollars per share)	$ 23.87
Stock Options Outstanding, Number of Shares | shares	1,777,216
Stock Options Outstanding, Remaining Contractual Term	5 years 6 months 7 days
Stock Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 22.77
Stock Options Exercisable, Number of Shares | shares	1,756,016
Stock Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 22.76
$23.96 - $35.94
Stock options outstanding and exercisable by exercise price
Range of Exercise Prices, lower limit (in dollars per share)	23.96
Range of Exercise Prices, upper limit (in dollars per share)	$ 35.94
Stock Options Outstanding, Number of Shares | shares	2,312,270
Stock Options Outstanding, Remaining Contractual Term	7 years 10 months 28 days
Stock Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 32.08
Stock Options Exercisable, Number of Shares | shares	1,168,530
Stock Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 31.65
$35.99 - $53.99
Stock options outstanding and exercisable by exercise price
Range of Exercise Prices, lower limit (in dollars per share)	35.99
Range of Exercise Prices, upper limit (in dollars per share)	$ 53.99
Stock Options Outstanding, Number of Shares | shares	2,926,646
Stock Options Outstanding, Remaining Contractual Term	8 years 3 months 21 days
Stock Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 40.12
Stock Options Exercisable, Number of Shares | shares	992,672
Stock Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 37.52

Stock-Based Compensation - FV o

Stock-Based Compensation - FV of employee stock options (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Options to purchase common stock
Weighted average assumptions for estimated fair value of employee stock options
Common stock fair value per share minimum	30.65	20.69	29.96
Common stock fair value per share maximum	49.47	45.91	44.19
Expected volatility, low end of range (as a percent)	53.91%	52.93%	60.67%
Expected volatility, high end of range (as a percent)	56.82%	58.95%	61.33%
Risk-free interest rate, low end of range (as a percent)	0.47%	0.29%	1.37%
Risk-free interest rate, high end of range (as a percent)	1.33%	1.71%	2.60%
Compensation expense
Unamortized compensation expense related to unvested awards	$ 54.5	$ 48.9
Period to recognize unamortized compensation expense	2 years 7 months 13 days
Options to purchase common stock | Minimum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	6 years	5 years 2 months 23 days	5 years 2 months 23 days
Options to purchase common stock | Maximum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	7 years 7 months 24 days	7 years 7 months 24 days	6 years 7 months 2 days
Employee stock purchase plan
Weighted average assumptions for estimated fair value of employee stock options
Expected volatility, low end of range (as a percent)	46.08%	50.77%	50.77%
Expected volatility, high end of range (as a percent)	66.37%	66.37%	71.37%
Risk-free interest rate, low end of range (as a percent)	0.04%	0.09%	1.47%
Risk-free interest rate, high end of range (as a percent)	1.65%	1.65%	2.70%
Compensation expense
Unamortized compensation expense related to unvested awards	$ 2.3	$ 0.9
Period to recognize unamortized compensation expense	1 year 11 months 8 days
Employee stock purchase plan | Minimum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	6 months	6 months	6 months
Employee stock purchase plan | Maximum
Weighted average assumptions for estimated fair value of employee stock options
Expected term (years)	2 years	2 years	2 years

Stock Based Compensation - Rest

Stock Based Compensation - Restricted stock units (Details) - Restricted stock units $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Stock-based compensation
Beginning balance | shares	358,825	90,006
Granted | shares	670,700	348,288
Vested | shares	(151,555)	(62,355)
Forfeited | shares	(51,822)	(17,114)
Ending balance | shares	826,148	358,825
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 33.04	$ 34.66
Weighted Average Grant Date Fair Value, Granted | $ / shares	39.11	32.51
Weighted Average Grant Date Fair Value, Vested | $ / shares	32.76	32.61
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	36.68	32.33
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 37.79	$ 33.04
Compensation expense
Unamortized compensation expense related to unvested restricted stock units | $	$ 24.8	$ 8.5
Period to recognize unamortized compensation expense	1 year 11 months 12 days

Leases (Details)

Leases (Details)	Jul. 01, 2022USD ($)ft²	Jun. 30, 2021USD ($)ft²item	Dec. 31, 2021USD ($)	Sep. 30, 2026USD ($)ft²	Dec. 31, 2020USD ($)
Lessee, Lease, Description [Line Items]
Option to extend			true
2022			$ 2,097,000
2023			5,566,000
2024			5,713,000
2025			5,817,000
2026			5,279,000
Thereafter			52,117,000
Total undiscounted lease payments			76,589,000
Less: Tenant allowance			(17,032,000)
Less: Imputed interest			(25,588,000)
Present value of lease payments			33,969,000
Lease liability - long-term			$ 33,969,000		$ 9,739,000
Monrovia, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Area of property | ft²		7,020
Initial base monthly rent		$ 15,000
Lease term		18 months
Renewal term			5 years
ROU assets exchanged for operating lease liabilities			$ 300,000
Monrovia, CA - office and laboratory space with additional space
Lessee, Lease, Description [Line Items]
Renewal term			5 years
San Diego, CA - office space
Lessee, Lease, Description [Line Items]
Renewal term			5 years
Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Area of property | ft²		129,543
Phases of lease term | item		2
ROU assets exchanged for operating lease liabilities			$ 29,700,000
Forecast | Pasadena, CA - office and laboratory space
Lessee, Lease, Description [Line Items]
Area of property | ft²	83,083			46,460
Initial base monthly rent	$ 386,335.95
Rent expense per square foot	4.65
Rent increase (as a percentage)	3.00%
Improvement allowance	$ 17,032,015			$ 3,252,000
Lease term	13 years

Leases - Lease costs (Details)

Leases - Lease costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases
Operating lease cost	$ 4,342	$ 2,503	$ 2,596
Variable lease cost	58	150	80
Total lease costs	4,400	2,653	2,676
Cash paid for amounts included in the measurement of lease liabilities	$ 2,773	$ 2,233	$ 1,929
Remaining lease term	12 years 3 months 18 days	7 years 4 months 24 days	5 years 6 months
Discount rate	5.80%	5.50%	5.50%

Collaboration and Licensing A_3

Collaboration and Licensing Agreements (Details)	Nov. 12, 2021USD ($)shares	Oct. 01, 2021USD ($)itemD$ / shares	Feb. 04, 2020USD ($)shares	Mar. 29, 2019USD ($)	Dec. 31, 2021USD ($)itemshares	Nov. 30, 2021USD ($)	Sep. 30, 2021USD ($)shares	Aug. 31, 2021	Jun. 30, 2021USD ($)shares	Dec. 31, 2020USD ($)shares	Nov. 30, 2020USD ($)item	Aug. 31, 2020USD ($)item	Apr. 30, 2020USD ($)	Jan. 31, 2020USD ($)itemOption	Dec. 31, 2019USD ($)	Nov. 30, 2019USD ($)	Mar. 31, 2019USD ($)company	Feb. 28, 2019	Oct. 31, 2017USD ($)shares	Jun. 30, 2016item	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020item	Sep. 30, 2019USD ($)	Dec. 31, 2021USD ($)itemProgramshares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)item	Dec. 31, 2017USD ($)shares	May 31, 2018USD ($)	Sep. 30, 2015USD ($)item
Collaboration research and licensing agreements
Receivable					$ 66,384,000					$ 11,443,000															$ 66,384,000	$ 11,443,000
Proceeds from sale of common stock																									28,920,000
Revenue recorded																									275,111,000	122,694,000	$ 156,700,000
Other income																									(1,274,000)	95,000	(256,000)
Impairment																									762,000
Net gains recognized on sale of equity securities																									18,301,000	801,000
Unrealized gains (losses) recognized on equity securities																									20,988,000	(696,000)
Net gains recognized on equity securities																									39,289,000	105,000
Deferred revenue					37,300,000					92,600,000															37,300,000	92,600,000
Licensing
Collaboration research and licensing agreements
Revenue recorded																									80,800,000	50,200,000	112,200,000
Royalties
Collaboration research and licensing agreements
Revenue recorded																									80,300,000	17,800,000	5,000,000
Milestone
Collaboration research and licensing agreements
Revenue recorded																									21,000,000	50,200,000	23,200,000
Research collaboration
Collaboration research and licensing agreements
Revenue recorded																									93,000,000	4,500,000	16,300,000
Aimmune
Collaboration research and licensing agreements
Revenue recorded																										9,600,000
Alexion Pharmaceuticals, Inc.
Collaboration research and licensing agreements
Revenue recorded																									$ 22,200,000	26,200,000	13,000,000
Amgen, Inc.
Collaboration research and licensing agreements
Revenue recorded																											5,000,000
Astellas
Collaboration research and licensing agreements
Revenue recorded																										3,500,000	14,000,000
Astria/Catabasis | Common Stock
Collaboration research and licensing agreements
Shares received in noncash transaction | shares									259,206
Shares issued upon conversion | shares									3,580,539
Reverse stock split ratio								0.166
Number of shares | shares																									3,839,745
Genentech
Collaboration research and licensing agreements
Revenue recorded																									$ 2,500,000	3,500,000	113,900,000
Gilead
Collaboration research and licensing agreements
Revenue recorded																										13,500,000
MiRagen/Viridian
Collaboration research and licensing agreements
Revenue recorded																									7,500,000	6,000,000
MorphoSys
Collaboration research and licensing agreements
Revenue recorded																									18,400,000	39,000,000
Novartis
Collaboration research and licensing agreements
Revenue recorded																									43,100,000		10,000,000
Omeros
Collaboration research and licensing agreements
Revenue recorded																										5,000,000
Zenas Bio Pharma Limited
Collaboration research and licensing agreements
Revenue recorded																									14,900,000	16,100,000
Vir
Collaboration research and licensing agreements
Revenue recorded																									52,700,000	300,000	800,000
License, Development, and Commercialization Agreement | Aimmune
Collaboration research and licensing agreements
Transaction price			$ 9,600,000
Nonrefundable upfront payment			5,000,000
Potential milestone payment			$ 385,000,000
Revenue recognized																									0	9,600,000
Shares received in noncash transaction | shares			156,238
Purchase amount of share options or equity in noncash transaction			$ 4,600,000
Deferred revenue					0					$ 0															0	0
Option and license agreement | Alexion Pharmaceuticals, Inc.
Collaboration research and licensing agreements
Receivable					10,800,000																				10,800,000
Revenue recognized																									22,200,000	26,200,000	13,000,000
Deferred revenue					0																				0
Option and license agreement | Alexion Pharmaceuticals, Inc. | Royalties
Collaboration research and licensing agreements
Revenue recognized																									22,200,000	16,200,000	5,000,000
Option and license agreement | Alexion Pharmaceuticals, Inc. | Milestone
Collaboration research and licensing agreements
Revenue recognized																										10,000,000	8,000,000
Research and License Agreement | Amgen, Inc.
Collaboration research and licensing agreements
Potential milestone payment																														$ 255,000,000
Revenue recognized																									0	0	5,000,000
Deferred revenue					0																				0
Research and License Agreement | Amgen, Inc. | Discovery Program
Collaboration research and licensing agreements
Revenue recognized																								$ 5,000,000
Previous targets which bispecific technology will be applied | item																														5
Research and License Agreement | Astellas
Collaboration research and licensing agreements
Nonrefundable upfront payment				$ 15,000,000
Potential milestone payment				240,000,000
Revenue recognized																									0	3,500,000	14,000,000
Deferred revenue					0																				0
Research and License Agreement | Astellas | Bispecific
Collaboration research and licensing agreements
Revenue recognized																											13,600,000
Research and License Agreement | Astellas | Research service
Collaboration research and licensing agreements
Revenue recognized				1,400,000
Research and License Agreement | Astellas | Milestone
Collaboration research and licensing agreements
Revenue recognized																										2,500,000
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
Transaction price																	$ 120,000,000
Nonrefundable upfront payment																	$ 120,000,000
Percentage of profits on net sales of the product																	45.00%
Research license term																	2 years	2 years
Revenue recognized																									2,500,000	3,500,000	113,900,000
Number of companies that conduct integrated research plan | company																	2
Cost sharing receivable (payable)					(2,200,000)																				(2,200,000)
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
Transaction price					8,300,000																				8,300,000
Revenue recognized																									2,500,000	3,500,000	2,200,000
Deferred revenue					0																				0
Standalone selling price																	4,200,000
Collaboration and License Agreement | Genentech | Licensing
Collaboration research and licensing agreements
Transaction price																	111,700,000
Collaboration and License Agreement | Genentech | Maximum | XmAb306
Collaboration research and licensing agreements
Potential milestone payment																	160,000,000
Collaboration and License Agreement | Genentech | Maximum | XmAb435
Collaboration research and licensing agreements
Potential milestone payment																	180,000,000
Collaboration and License Agreement | Genentech | Cost approach | Research service
Collaboration research and licensing agreements
Standalone selling price																	8,500,000
Collaboration and License Agreement | Genentech | Cost approach | Licensing
Collaboration research and licensing agreements
Standalone selling price																	$ 114,400,000
Collaboration and License Agreement | Janssen Biotech, Inc
Collaboration research and licensing agreements
Transaction price											$ 50,000,000
Nonrefundable upfront payment											50,000,000
Potential milestone payment											$ 662,500,000
Research license term		2 years
Revenue recognized					5,000,000																				113,800,000	0
Deferred revenue					$ 37,300,000																				$ 37,300,000
Percentage of funding for development costs											20.00%
Percentage of co-detailing activities											30.00%
Number of collaboration and license agreements | item					2																				2
Collaboration and License Agreement | Janssen Biotech, Inc | Milestone
Collaboration research and licensing agreements
Revenue recognized																									$ 5,000,000
Collaboration and License Agreement | Janssen Biotech, Inc | Research collaboration
Collaboration research and licensing agreements
Revenue recognized																									50,000,000
Collaboration and License Agreement | MorphoSys
Collaboration research and licensing agreements
Revenue recognized																											0
Deferred revenue					$ 0																				0
Collaboration and License Agreement | MorphoSys | Royalties
Collaboration research and licensing agreements
Revenue recognized																									5,900,000	1,500,000
Contract asset					1,900,000																				1,900,000
Collaboration and License Agreement | MorphoSys | Milestone
Collaboration research and licensing agreements
Revenue recognized																									12,500,000	37,500,000
Collaboration and License Agreement | Novartis
Collaboration research and licensing agreements
Receivable					600,000																				600,000
Revenue recognized																									43,100,000	0	10,000,000
Deferred revenue					0																				$ 0
Remaining cost sharing settlement amount																$ 1,400,000
Collaboration and License Agreement | Novartis | Bispecific FC Technologies
Collaboration research and licensing agreements
Number of development stage products | item																				2
Collaboration and License Agreement | Novartis | Global Discovery Program
Collaboration research and licensing agreements
Number of programs delivered | Program																									2
Proceeds from milestone payments															$ 10,000,000									10,000,000
Revenue recognized																								$ 10,000,000	$ 40,100,000			$ 40,100,000
Collaboration and License Agreement | Novartis | Global Discovery Program | Maximum
Collaboration research and licensing agreements
Number of antibody targets for which bispecific technology applied | item																				4
Collaboration and License Agreement | Novartis | FC Licenses | Maximum
Collaboration research and licensing agreements
Number of targets against which non-exclusive license is provided | item																				10
Technology License Agreement | Quellis | Maximum
Collaboration research and licensing agreements
Potential milestone payment																													$ 66,000,000
Technology License Agreement | Astria/Catabasis
Collaboration research and licensing agreements
Impairment					800,000																				800,000
Unrealized gains (losses) recognized on equity securities																									4,500,000
Deferred revenue					0																				0
Technology License Agreement | Astria/Catabasis | Common Stock
Collaboration research and licensing agreements
Reverse stock split ratio								0.166
Technology License Agreement | Gilead
Collaboration research and licensing agreements
Transaction price														$ 13,500,000
Nonrefundable upfront payment														6,000,000
Potential milestone payment														$ 67,000,000
Revenue recognized													$ 7,500,000												0	13,500,000
Deferred revenue					$ 0																				0
Options exercised														3									3
Number of compounds | item														3
Option fee														$ 7,500,000
Technology License Agreement | MiRagen/Viridian
Collaboration research and licensing agreements
Number of antibodies | item					3
Transaction price					$ 6,000,000																				6,000,000
Research license term					1 year
Revenue recognized																									7,500,000	6,000,000
Shares received in noncash transaction | shares					394,737					322,407
Purchase amount of share options or equity in noncash transaction					$ 7,500,000					$ 6,000,000
Deferred revenue					$ 0																				0
Technology License Agreement | MiRagen/Viridian | Common Stock
Collaboration research and licensing agreements
Shares received in noncash transaction | shares					394,737					322,407
Technology License Agreement | MiRagen/Viridian | Maximum
Collaboration research and licensing agreements
Potential milestone payment					$ 24,750,000					$ 55,000,000															24,750,000	55,000,000
Technology License Agreement | MiRagen/Viridian | Xtend Fc Technology
Collaboration research and licensing agreements
Transaction price					6,000,000																				6,000,000
Technology License Agreement | MiRagen/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
Nonrefundable upfront payment												$ 5,000,000
Revenue recognized																									0	5,000,000
Deferred revenue					0																				0
Number of additional antibodies | item												3
Technology License Agreement | Omeros | Maximum
Collaboration research and licensing agreements
Potential milestone payment												$ 65,000,000
Technology License Agreement | Bristol Myers Squibb
Collaboration research and licensing agreements
Revenue recognized																									0
Deferred revenue					0																				0
License Agreement | INmune
Collaboration research and licensing agreements
Revenue recognized																									0	0	0
Shares received in noncash transaction | shares																			1,585,000
Purchase amount of share options or equity in noncash transaction																			$ 10,000,000
Consideration on sale of option									$ 18,300,000
Cash consideration on sale of option									15,000,000
Shares issues on sale of option value									3,300,000
Net gains recognized on sale of equity securities									$ 18,300,000																18,300,000
Unrealized gains (losses) recognized on equity securities																									$ 15,100,000
Option term																			6 years
Number of shares | shares									192,533
License Agreement | INmune | Common Stock
Collaboration research and licensing agreements
Shares received in noncash transaction | shares																												1,585,000
Purchase amount of share options or equity in noncash transaction							$ 800,000
Cash consideration on sale of option									$ 15,000,000
Shares issued upon conversion | shares									192,533
Unrealized gains (losses) recognized on equity securities																					$ 2,000,000
Gain on fair value of option																					1,100,000
Net gains recognized on equity securities							$ 900,000
Additional equity interests (as a percentage)									10.00%																			10.00%
Option to acquire shares | shares																			108,000									108,000
Number of shares | shares							108,000																		1,885,533
License Agreement | INmune | Maximum
Collaboration research and licensing agreements
Additional equity interests (as a percentage)																			10.00%
License Agreement | INmune | Other Income
Collaboration research and licensing agreements
Unrealized gains (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 Bio Pharma Limited
Collaboration research and licensing agreements
Transaction price						$ 14,900,000					$ 16,100,000
Revenue recognized																									$ 14,900,000	16,100,000
Purchase amount of share options or equity in noncash transaction											$ 16,100,000
Deferred revenue					$ 0																				$ 0
Percentage of equity of private company						15.00%					15.00%
Number of drug candidates | item											3
Milestones or royalties in transaction price						$ 0					$ 0
Number of collaboration and license agreements | item					2																				2
Patent License Agreement | Vir
Collaboration research and licensing agreements
Receivable					$ 45,000,000																				$ 45,000,000
Potential milestone payment															154,500,000												154,500,000
Revenue recognized																									52,700,000	300,000	800,000
Contract asset									$ 500,000													$ 500,000
Deferred revenue					0																				0
Upfront and milestone payment received																											$ 1,500,000
Number of different target programs | item																											2
Patent License Agreement | Vir | Royalties
Collaboration research and licensing agreements
Revenue recognized																									52,200,000
Second Collaboration And License Agreement [Member] | Janssen Biotech, Inc
Collaboration research and licensing agreements
Discount on proceeds from sale																									3,900,000
Transaction price					96,100,000																				96,100,000
Share development percentage						80.00%
Number of candidates for which option to advance for development and commercialization | item		4
Proceeds from sale of common stock	$ 28,900,000
Nonrefundable upfront payment		$ 100,000,000																							100,000,000
Potential milestone payment		$ 1,187,500,000
Research license term		2 years
Number of drug candidates | item		4
Percentage of responsibility for development costs						20.00%
Second Collaboration And License Agreement [Member] | Janssen Biotech, Inc | Research service
Collaboration research and licensing agreements
Performance obligation					37,600,000	$ 37,600,000																			37,600,000
Revenue recognized																									300,000
Standalone selling price					37,600,000																				37,600,000
Second Collaboration And License Agreement [Member] | Janssen Biotech, Inc | Licensing
Collaboration research and licensing agreements
Transaction price					58,500,000																				58,500,000
Revenue recognized						58,500,000
Standalone selling price					58,500,000																				58,500,000
Second Collaboration And License Agreement [Member] | Johnson & Johnson Innovation, JJDC, Inc. | Common Stock
Collaboration research and licensing agreements
Total equity shares | shares	748,062
Number of trading days | D		30
Weighted average price | $ / shares		$ 33.4197
Proceeds from sale of common stock		$ 25,000,000
Second Collaboration And License Agreement [Member] | Zenas Bio Pharma Limited
Collaboration research and licensing agreements
Warrants						14,900,000
Potential milestone payment						$ 470,000,000
Development-based | License, Development, and Commercialization Agreement | Aimmune
Collaboration research and licensing agreements
Potential milestone payment			22,000,000
Development-based | Research and License Agreement | Astellas
Collaboration research and licensing agreements
Potential milestone payment				32,500,000
Development-based | Collaboration and License Agreement | Janssen Biotech, Inc
Collaboration research and licensing agreements
Potential milestone payment											161,900,000
Development-based | Technology License Agreement | Quellis
Collaboration research and licensing agreements
Potential milestone payment																													6,000,000
Development-based | Technology License Agreement | Gilead
Collaboration research and licensing agreements
Potential milestone payment														10,000,000
Development-based | Technology License Agreement | MiRagen/Viridian
Collaboration research and licensing agreements
Potential milestone payment					1,750,000					10,000,000															1,750,000	10,000,000
Development-based | Technology License Agreement | Omeros
Collaboration research and licensing agreements
Potential milestone payment												15,000,000
Development-based | Patent License Agreement | Vir
Collaboration research and licensing agreements
Potential milestone payment															4,500,000												$ 4,500,000
Development-based | Second Collaboration And License Agreement [Member] | Janssen Biotech, Inc
Collaboration research and licensing agreements
Potential milestone payment		289,400,000
Regulatory-based | License, Development, and Commercialization Agreement | Aimmune
Collaboration research and licensing agreements
Potential milestone payment			53,000,000
Regulatory-based | Research and License Agreement | Astellas
Collaboration research and licensing agreements
Potential milestone payment				57,500,000
Regulatory-based | Collaboration and License Agreement | Janssen Biotech, Inc
Collaboration research and licensing agreements
Potential milestone payment											240,600,000
Regulatory-based | Technology License Agreement | Quellis
Collaboration research and licensing agreements
Potential milestone payment																													30,000,000
Regulatory-based | Technology License Agreement | Gilead
Collaboration research and licensing agreements
Potential milestone payment														27,000,000
Regulatory-based | Technology License Agreement | MiRagen/Viridian
Collaboration research and licensing agreements
Potential milestone payment					3,000,000					20,000,000															3,000,000	20,000,000
Regulatory-based | Technology License Agreement | Omeros
Collaboration research and licensing agreements
Potential milestone payment												25,000,000
Regulatory-based | Patent License Agreement | Vir
Collaboration research and licensing agreements
Potential milestone payment															30,000,000												30,000,000
Regulatory-based | Second Collaboration And License Agreement [Member] | Janssen Biotech, Inc
Collaboration research and licensing agreements
Potential milestone payment		378,100,000
Sales-based | License, Development, and Commercialization Agreement | Aimmune
Collaboration research and licensing agreements
Potential milestone payment			$ 310,000,000
Sales-based | Research and License Agreement | Astellas
Collaboration research and licensing agreements
Potential milestone payment				$ 150,000,000
Sales-based | Collaboration and License Agreement | Janssen Biotech, Inc
Collaboration research and licensing agreements
Potential milestone payment											$ 260,000,000
Sales-based | Technology License Agreement | Quellis
Collaboration research and licensing agreements
Potential milestone payment																													$ 30,000,000
Sales-based | Technology License Agreement | Gilead
Collaboration research and licensing agreements
Potential milestone payment														$ 30,000,000
Sales-based | Technology License Agreement | MiRagen/Viridian
Collaboration research and licensing agreements
Potential milestone payment					$ 20,000,000					$ 25,000,000															$ 20,000,000	$ 25,000,000
Sales-based | Technology License Agreement | Omeros
Collaboration research and licensing agreements
Potential milestone payment												$ 25,000,000
Sales-based | Patent License Agreement | Vir
Collaboration research and licensing agreements
Potential milestone payment															$ 120,000,000												$ 120,000,000
Sales-based | Second Collaboration And License Agreement [Member] | Janssen Biotech, Inc
Collaboration research and licensing agreements
Potential milestone payment		$ 520,000,000

Collaborative and Licensing Agr

Collaborative and Licensing Agreements - Revenue Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	$ 275,111	$ 122,694	$ 156,700
Deferred revenue	37,300	92,600
Research collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	93,000	4,500	16,300
Milestone
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	21,000	50,200	23,200
Licensing
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	80,800	50,200	112,200
Royalties
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	80,300	17,800	5,000
Aimmune
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded		9,600
Alexion Pharmaceuticals, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	22,200	26,200	13,000
Amgen, Inc.
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded			5,000
Astellas
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded		3,500	14,000
Genentech
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	2,500	3,500	113,900
Gilead
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded		13,500
Janssen
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	113,800
MorphoSys
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	18,400	39,000
Novartis
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	43,100		10,000
MiRagen/Viridian
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	7,500	6,000
Omeros
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded		5,000
Vir
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	52,700	300	$ 800
Zenas Bio Pharma Limited
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recorded	$ 14,900	$ 16,100

401(k) Plan (Details)

401(k) Plan (Details) - USD ($) $ in Millions	Mar. 31, 2020	Jan. 01, 2018	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan employer matching contribution percent	4.00%	3.50%
Employer contributions			$ 1.1	$ 0.8	$ 0.6
Vesting period			3 years
Annual vesting percentage			33.00%
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%