FibroGen (FGEN) 10-Q 8 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Jul. 31, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Trading Symbol	FGEN
Entity Registrant Name	FIBROGEN, INC.
Entity Central Index Key	0000921299
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.01 par value
Security Exchange Name	NASDAQ
Entity File Number	001-36740
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0357827
Entity Address, Address Line One	409 Illinois Street
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94158
City Area Code	415
Local Phone Number	978-1200
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock Shares Outstanding		93,741,180

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 167,758	$ 171,223
Short-term investments	270,375	233,967
Accounts receivable, net ($26,779 and $10,930 from related parties)	33,573	17,401
Inventories	40,899	31,015
Prepaid expenses and other current assets	8,038	20,453
Total current assets	520,643	474,059
Restricted time deposits	2,072	2,072
Long-term investments	45,920	167,796
Property and equipment, net	24,505	28,277
Equity method investment in unconsolidated variable interest entity	4,494	3,825
Operating lease right-of-use assets	84,654	91,112
Other assets	4,501	6,680
Total assets	686,789	773,821
Current liabilities:
Accounts payable	29,360	26,097
Accrued and other current liabilities ($43,286 and $4 to a related party)	193,099	172,599
Deferred revenue ($5,204 and $3,201 to related parties)	6,897	15,857
Operating lease liabilities, current	10,984	10,944
Total current liabilities	240,340	225,497
Product development obligations	16,439	17,613
Deferred revenue, net of current ($49,2733 and $25,891 to a related party)	205,351	186,801
Operating lease liabilities, non-current	83,080	88,776
Other long-term liabilities	17,832	26,021
Total liabilities	563,042	544,708
Commitments and Contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value; 125,000 shares authorized; no shares issued and outstanding at June 30, 2022 and December 31, 2021
Common stock, $0.01 par value; 225,000 shares authorized at June 30, 2022 and December 31, 2021; 93,733 and 92,881 shares issued and outstanding at June 30, 2022 and December 31, 2021	937	929
Additional paid-in capital	1,509,636	1,476,414
Accumulated other comprehensive loss	(6,930)	(4,163)
Accumulated deficit	(1,399,863)	(1,264,034)
Total stockholders’ equity	103,780	209,146
Non-controlling interests	19,967	19,967
Total equity	123,747	229,113
Total liabilities, stockholders’ equity and non-controlling interests	$ 686,789	$ 773,821

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Accounts receivable from related parties	$ 26,779	$ 10,930
Accrued and other current liabilities to related party	43,286	4
Deferred revenue current to related party	5,204	3,201
Deferred revenue non-current to related party	$ 49,733	$ 25,891
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	125,000	125,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	225,000	225,000
Common stock, shares issued	93,733	92,881
Common stock, shares outstanding	93,733	92,881

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue:
Total revenue	$ 29,806	$ 24,364	$ 90,633	$ 62,793
Operating costs and expenses:
Cost of goods sold	$ 6,809	$ 3,078	$ 11,048	$ 6,479
Cost, Product and Service [Extensible List]	Product Revenue, Net [Member]	Product Revenue, Net [Member]	Product Revenue, Net [Member]	Product Revenue, Net [Member]
Research and development	$ 70,963	$ 122,567	$ 159,981	$ 197,243
General and administrative			60,820	63,334
Selling, general and administrative	30,258	32,554
Total operating costs and expenses	108,030	158,199	231,849	267,056
Loss from operations	(78,224)	(133,835)	(141,216)	(204,263)
Interest and other, net
Interest expense	(141)	(355)	(238)	(856)
Interest income and other income (expenses), net	5,199	(363)	4,876	(817)
Total interest and other, net	5,058	(718)	4,638	(1,673)
Loss before income taxes	(73,166)	(134,553)	(136,578)	(205,936)
Provision for (benefit from) income taxes	23	(3)	136	130
Investment income in unconsolidated variable interest entity	565	562	885	323
Net loss	$ (72,624)	$ (133,988)	$ (135,829)	$ (205,743)
Net loss per share - basic	$ (0.78)	$ (1.45)	$ (1.46)	$ (2.24)
Net loss per share - diluted	$ (0.78)	$ (1.45)	$ (1.46)	$ (2.24)
Weighted average number of common shares used to calculate net loss per share - basic	93,475	92,276	93,260	91,983
Weighted average number of common shares used to calculate net loss per share - diluted	93,475	92,276	93,260	91,983
License Revenue [Member]
Revenue:
Total revenue	$ 0	$ 0	$ 22,590	$ 0
Development and Other Revenue [Member]
Revenue:
Total revenue	5,457	19,641	17,219	34,228
Product Revenue, Net [Member]
Revenue:
Total revenue	23,256	13,371	42,137	28,733
Drug Product Revenue [Member]
Revenue:
Total revenue	$ 1,093	$ 8,648	$ 8,687	$ (168)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations (Unaudited) (Parenthetical) - Astellas Agreement [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
License and milestone revenue from a related party	$ 0	$ 0	$ 22,590	$ 0
Collaboration services and other revenue from a related party	1,825	2,645	7,005	6,256
Product revenue from a related party	19,736	11,760	35,959	22,167
Drug product revenue from a related party	$ 1,093	$ (1,974)	$ 8,687	$ 2,056

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net loss	$ (72,624)	$ (133,988)	$ (135,829)	$ (205,743)
Other comprehensive income (loss):
Foreign currency translation adjustments	159	40	408	(30)
Available-for-sale investments:
Unrealized gain (loss) on investments, net of tax effect	(584)	17	(3,175)	(38)
Other comprehensive gain (loss), net of taxes	(425)	57	(2,767)	(68)
Comprehensive loss	$ (73,049)	$ (133,931)	$ (138,596)	$ (205,811)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2020	$ 441,449	$ 914	$ 1,399,774	$ (4,499)	$ (974,011)	$ 19,271
Balance, Shares at Dec. 31, 2020		91,440,633
Net loss	(205,743)	$ 0	0	0	(205,743)	0
Change in unrealized gain or loss on investments	(38)	0	0	(38)	0	0
Foreign currency translation adjustments	(30)	0	0	(30)	0	0
Shares issued from stock plans, net of payroll taxes paid	5,828	$ 12	5,816	0	0	0
Shares issued from stock plans, net of payroll taxes paid, Shares		1,168,296
Stock-based compensation	38,385	$ 0	38,385	0	0	0
Balance at Jun. 30, 2021	279,851	$ 926	1,443,975	(4,567)	(1,179,754)	19,271
Balance, Shares at Jun. 30, 2021		92,608,929
Balance at Mar. 31, 2021	390,273	$ 921	1,420,471	(4,624)	(1,045,766)	19,271
Balance, Shares at Mar. 31, 2021		92,080,399
Net loss	(133,988)	$ 0	0	0	(133,988)	0
Change in unrealized gain or loss on investments	17			17
Foreign currency translation adjustments	40	0	0	40	0	0
Shares issued from stock plans, net of payroll taxes paid	4,508	$ 5	4,503	0	0	0
Shares issued from stock plans, net of payroll taxes paid, Shares		528,530
Stock-based compensation	19,001	$ 0	19,001	0	0	0
Balance at Jun. 30, 2021	279,851	$ 926	1,443,975	(4,567)	(1,179,754)	19,271
Balance, Shares at Jun. 30, 2021		92,608,929
Balance at Dec. 31, 2021	229,113	$ 929	1,476,414	(4,163)	(1,264,034)	19,967
Balance, Shares at Dec. 31, 2021		92,880,533
Net loss	(135,829)	$ 0	0	0	(135,829)	0
Change in unrealized gain or loss on investments	(3,175)	0	0	(3,175)	0	0
Foreign currency translation adjustments	408	0	0	408	0	0
Shares issued from stock plans, net of payroll taxes paid	(580)	$ 8	(588)	0	0	0
Shares issued from stock plans, net of payroll taxes paid, Shares		852,501
Stock-based compensation	33,810	$ 0	33,810	0	0	0
Balance at Jun. 30, 2022	123,747	$ 937	1,509,636	(6,930)	(1,399,863)	19,967
Balance, Shares at Jun. 30, 2022		93,733,034
Balance at Mar. 31, 2022	178,015	$ 933	1,490,859	(6,505)	(1,327,239)	19,967
Balance, Shares at Mar. 31, 2022		93,288,584
Net loss	(72,624)				(72,624)
Change in unrealized gain or loss on investments	(584)	0	0	(584)	0	0
Foreign currency translation adjustments	159	0	0	159	0	0
Shares issued from stock plans, net of payroll taxes paid	2,123	$ 4	2,119	0	0	0
Shares issued from stock plans, net of payroll taxes paid, Shares		444,450
Stock-based compensation	16,658	$ 0	16,658	0	0	0
Balance at Jun. 30, 2022	$ 123,747	$ 937	$ 1,509,636	$ (6,930)	$ (1,399,863)	$ 19,967
Balance, Shares at Jun. 30, 2022		93,733,034

Condensed Consolidated Statem_5

Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities
Net loss	$ (135,829)	$ (205,743)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	4,966	5,242
Amortization of finance lease right-of-use assets	269	4,393
Net accretion of premium and discount on investments	1,512	767
Unrealized loss on equity investments	0	4
Investment income in unconsolidated variable interest entity	(885)	(323)
(Gain) / loss on disposal of property and equipment	(1)	13
Stock-based compensation	33,810	38,385
Expense for acquired in-process research and development asset	0	25,000
Realized loss on sales of available-for-sale securities	5	8
Changes in operating assets and liabilities:
Accounts receivable, net	(16,200)	17,868
Inventories	(10,858)	(7,861)
Prepaid expenses and other current assets	11,596	2,231
Operating lease right-of-use assets	6,256	(1,800)
Other assets	1,487	(3,066)
Accounts payable	4,192	(1,013)
Accrued and other liabilities	61,005	27,745
Operating lease liabilities, current	108	295
Deferred revenue	9,651	33,078
Accrued interest for finance lease liabilities	14	(73)
Operating lease liabilities, non-current	(5,574)	1,388
Other long-term liabilities	(7,064)	(8,065)
Net cash used in operating activities	(41,540)	(71,527)
Investing activities
Purchases of property and equipment	(2,543)	(2,215)
Payment made for acquired in-process research and development asset	(35,000)	0
Proceeds from sale of property and equipment	6	0
Purchases of available-for-sale securities	(59,123)	(266,647)
Proceeds from sales of available-for-sale securities	7,382	4,000
Proceeds from maturities of investments	132,518	10,610
Net cash provided by (used in) investing activities	43,240	(254,252)
Financing activities
Repayments of finance lease liabilities	(23)	(5,326)
Repayments of lease obligations	(201)	(201)
Cash paid for payroll taxes on restricted stock unit releases	(3,361)	(5,928)
Proceeds from issuance of common stock	2,779	11,756
Net cash provided by (used in) financing activities	(806)	301
Effect of exchange rate change on cash and cash equivalents	(4,359)	446
Net increase (decrease) in cash and cash equivalents	(3,465)	(325,032)
Total cash and cash equivalents at beginning of period	171,223	678,393
Total cash and cash equivalents at end of period	$ 167,758	$ 353,361

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Significant Accounting Policies	1. Significant Accounting Policies Description of Operations FibroGen, Inc. (“FibroGen” or the “Company”) is headquartered in San Francisco, California, with subsidiary offices in Beijing and Shanghai, People’s Republic of China (“China”). FibroGen is a leading biopharmaceutical company developing and commercializing a pipeline of first-in-class therapeutics. The Company applies its pioneering expertise in hypoxia-inducible factor ("HIF") biology, 2-oxoglutarate enzymology, and connective tissue growth factor to advance innovative medicines for the treatment of anemia, fibrotic disease, and cancer. Pamrevlumab, a human monoclonal antibody targeting connective tissue growth factor, is in Phase 3 clinical development for the treatment of idiopathic pulmonary fibrosis, locally advanced unresectable pancreatic cancer and Duchenne muscular dystrophy. To date, the Company has retained exclusive worldwide rights for pamrevlumab. Roxadustat is an oral small molecule inhibitor of HIF prolyl hydroxylase (“HIF-PH”) activity. Roxadustat (爱瑞卓 ® , EVRENZO TM ) is now approved in China, Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (“CKD”) patients on dialysis and those not on dialysis. Astellas Pharma Inc. (“Astellas”) and FibroGen are collaborating on the development and commercialization of roxadustat for the potential treatment of anemia in territories including Japan, Europe, Turkey, Russia and the Commonwealth of Independent States, the Middle East, and South Africa. FibroGen and AstraZeneca are collaborating on the development and commercialization of roxadustat for the potential treatment of anemia in the U.S., China, other markets in the Americas, Australia/New Zealand, and Southeast Asia. Roxadustat is in Phase 3 clinical development for anemia associated with myelodysplastic syndromes. The Company has completed a Phase 2 study of roxadustat in chemotherapy-induced anemia and is running a Phase 3 trial of roxadustat chemotherapy-induced anemia in China. The Company has a pipeline of late-stage clinical programs as well as preclinical drug candidates at various stages of development that include both small molecules and biologics. The Company has leveraged its internally developed 2-oxoglutarate and connective tissue growth factor biology expertise as well as in-licensing of additional programs, such as antibodies targeting Galectin-9 protein (“Gal-9”) and C-C Motif Chemokine Receptor 8 (“CCR8”), to further enhance its late-stage preclinical pipeline. FibroGen's goal is to build a diversified pipeline with novel drugs that will address unmet patient needs in oncology, immunology, and fibrosis. Basis of Presentation and Principles of Consolidation The condensed consolidated financial statements include the accounts of FibroGen, its wholly-owned subsidiaries and its majority-owned subsidiaries, FibroGen Europe Oy and FibroGen China Anemia Holdings, Ltd. All inter-company transactions and balances have been eliminated in consolidation. For the variable interest entity (“VIE”) for which FibroGen is not the primary beneficiary, the Company uses the equity method of accounting. The Company operates as one reportable segment — the discovery, development and commercialization of novel therapeutics to treat serious unmet medical needs. The unaudited condensed consolidated financial statements and related disclosures have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) applicable to interim financial reporting and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the U.S. Securities and Exchange Commission (“SEC”) and, therefore, do not include all information and footnote disclosures normally included in the annual consolidated financial statements. The financial information included herein should be read in conjunction with the consolidated financial statements and related notes in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed on February 28, 2022 and as amended on March 4, 2022 (“2021 Form 10-K”). Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no impact on previously reported financial position, results of operations, or cash flows. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions include valuation and recognition of revenue and deferred revenue, specifically, estimates in variable consideration for drug product sales, and estimates in transaction price per unit for the China manufacturing and supply obligation. On an ongoing basis, management reviews these estimates and assumptions. Changes in facts and circumstances may alter such estimates and actual results could differ from those estimates. In the Company’s opinion, the accompanying unaudited condensed consolidated financial statements include all normal recurring adjustments necessary for a fair statement of its financial position, results of operations and cash flows for the interim periods presented. Significant Accounting Policies The accounting policies used by the Company in its presentation of interim financial results are consistent with those presented in Note 2 to the consolidated financial statements included in the 2021 Form 10-K, except for the updates to the following: Stock-Based Compensation The Company maintains equity incentive plans under which incentive and nonqualified stock options are granted to employees, which are comprised of stock options, service-based restricted stock units ("RSUs"), performance-based RSUs and total shareholder return (“TSR”) awards. The Company measures and recognizes compensation expense for all stock options, service and performance-based restricted stock units granted to its employees and directors based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes valuation model to estimate the fair value of stock option awards. The determination of the grant date fair value of options using the Black-Scholes valuation model is affected by the Company’s estimated common stock fair value and requires management to make a number of assumptions including the expected life of the option, the volatility of the underlying stock, the risk-free interest rate and expected dividends. To estimate the fair value of the TSR awards, the Company uses the Monte Carlo valuation model to simulate the probabilities of achievement, which requires management to make a number of assumptions including 30-day average price, volatility of the underlying stock and the Company's peers, and the risk-free interest rate. The compensation cost of service-based stock options and restricted stock units is recognized net of any estimated forfeitures on a straight-line basis over the employee requisite service period. Compensation cost for performance-based RSUs is expensed over the respective vesting periods when the achievement of performance criteria is probable. Compensation cost for the TSR awards is recognized over the requisite service period, regardless of when, if ever, the market condition is satisfied. The Company believes that the fair value of stock options granted to non-employees is more reliably measured than the fair value of the services received. Net Loss per Share Potential common shares that would have the effect of increasing diluted earnings per share are considered to be anti-dilutive and as such, these shares are not included in the calculation of diluted earnings per share. The Company reported a net loss for each interim period presented. Therefore, dilutive common shares are not assumed to have been issued since their effect is anti-dilutive. Diluted weighted average shares excluded potential common shares related to stock options, restricted stock units (including service-based RSUs, performance-based RSUs and TSR awards) and shares to be purchased under the employee stock purchase plan totaling 14.2 million and 11.4 million for the three months ended June 30, 2022 and 2021 , and totaling 13.3 million and 9.4 million for the six months ended June 30, 2022 and 2021 , respectively, as they were anti-dilutive. Risks and Uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, the results of clinical trials and the achievement of milestones, research developments, actions by regulatory authorities, market acceptance of the Company’s product candidates, competition from other products and larger companies, intellectual property protection for the Company's proprietary technology, strategic relationships, and dependence on key individuals, suppliers, clinical organization, and other third parties. Recently Issued Accounting Guidance Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ ASU 2020-04” ) , which provides companies with optional financial reporting alternatives to reduce the cost and complexity associated with the accounting for contracts and hedging relationships affected by reference rate reform. This guidance is effective as of March 12, 2020 through December 31, 2022. Subsequently in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848): Scope , which clarifies ASU 2020-04 and provides certain optional expedients that allow derivative instruments impacted by changes in the interest rate used for margining, discounting or contract price alignment to qualify for certain optional relief. ASU 2021-01 is effective in the same timeframe as ASU2020-04. The relief offered by this guidance, if adopted, is available to companies for the period March 12, 2020 through December 31, 2022. The Company has certain lease arrangements that are linked to the London Inter-Bank Offered Rate ("LIBOR"). The Company is in the process of evaluating options for transitioning away from LIBOR and expects to complete this analysis by the time LIBOR is phased out. The Company did not elect to apply any of the expedients or exceptions as of and for the three and six months ended June 30, 2022 and is currently evaluating the impact on its condensed consolidated financial statements and related disclosures upon adoption of this guidance.

Collaboration Agreements, Licen

Collaboration Agreements, License Agreement and Revenues	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration Agreements, License Agreement and Revenues	2. Collaboration Agreements, License Agreement and Revenues Astellas Agreements Japan Agreement In June 2005, the Company entered into a collaboration agreement with Astellas for the development and commercialization (but not manufacture) of roxadustat for the treatment of anemia in Japan (“Japan Agreement”). Under this agreement, Astellas agreed to pay license fees, other upfront consideration and various milestone payments, totaling $ 172.6 million . The Japan Agreement also provides for tiered payments based on net sales of product (as defined) in the low 20% range of the list price published by Japan’s Ministry of Health, Labour and Welfare, adjusted for certain elements, after commercial launch. The aggregate amount of consideration received through June 30, 2022 totaled $ 105.1 million , excluding drug product revenue that is discussed separately below. Amounts recognized as license revenue and development revenue under the Japan Agreement with Astellas were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 Japan License revenue $ — $ — $ — $ — Development revenue $ 79 $ 99 $ 111 $ 179 The transaction price related to consideration received and accounts receivable has been allocated to each of the following performance obligations under the Japan Agreement with Astellas, along with any associated deferred revenue as follows (in thousands): Japan Agreement Cumulative Deferred Total License $ 100,347 $ — $ 100,347 Development revenue 16,709 — 16,709 Total license and development revenue $ 117,056 $ — $ 117,056 There was no rev enue resulting from changes to estimated variable consideration in the current period relating to performance obligations satisfied or partially satisfied in previous periods for the three months ended June 30, 2022 under the Japan Agreement. The Company does no t expect material variable consideration from estimated future co-development billing beyond the development period in the transaction price related to the Japan Agreement. In 2018, FibroGen and Astellas entered into an amendment to the Japan Agreement that allows Astellas to manufacture roxadustat drug product for commercialization in Japan (the “Japan Amendment”). The related drug product revenue, as described under Drug Product Revenue section below, was immaterial for the three months ended June 30, 2022, $( 2.0 ) million for the three months ended June 30, 2021, and $ 7.6 million and $ 2.1 million for the six months ended June 30, 2022 and 2021, respectively. Europe Agreement In April 2006, the Company entered into a separate collaboration agreement with Astellas for the development and commercialization of roxadustat for the treatment of anemia in Europe, the Middle East, the Commonwealth of Independent States and South Africa (“Europe Agreement”). Under the terms of the Europe Agreement, Astellas agreed to pay license fees, other upfront consideration and various milestone payments, totaling $ 745.0 million . U nder the Europe Agreement, Astellas committed to fund 50 % of joint development costs for Europe and North America, and all territory-specific costs. The Europe Agreement also provides for tiered payments based on net sales of product (as defined) in the low 20% range . On March 21, 2022, EVRENZO ® (roxadustat) was registered with the Russian Ministry of Health. The Company evaluated the regulatory milestone payment associated with the approval in Russia under the Europe Agreement and concluded that this milestone was achieved in the first quarter of 2022. Accordingly, the consideration of $ 25.0 million associated with this milestone was included in the transaction price and allocated to performance obligations under the Europe Agreement, all of which was recognized as revenue during the first quarter of 2022 from performance obligations satisfied. Such amount was billed and recorded in accounts receivable from Astellas as of March 31, 2022 and received in April 2022. The aggregate amount of consideration received under the Europe Agreement through June 30, 2022 totaled $ 685.0 million , excluding drug product revenue that is discussed separately below. Amounts recognized as license revenue and development revenue under the Europe Agreement with Astellas were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 Europe License revenue $ — $ — $ 22,590 $ — Development revenue $ 1,746 $ 2,546 $ 6,894 $ 6,077 The transaction price related to consideration received and accounts receivable has been allocated to each of the following performance obligations under the Europe Agreement with Astellas, along with any associated deferred revenue as follows (in thousands): Europe Agreement Cumulative Deferred Total License $ 618,975 $ — $ 618,975 Development revenue 277,536 — 277,536 Total license and development revenue $ 896,511 $ — $ 896,511 There was no rev enue resulting from changes to estimated variable consideration in the current period relating to performance obligations satisfied or partially satisfied in previous periods for three months ended June 30, 2022 under the Europe Agreement. The remainder of the transaction price related to the Europe Agreement includes $ 7.6 million of variable consideration from estimated future co-development billing and is estimated to be recognized over the remaining development service period. Under the Europe Agreement, Astellas has an option to purchase roxadustat bulk drug product in support of commercial supplies. During the first quarter of 2021, the Company entered into an EU Supply Agreement under the Europe Agreement with Astellas (“EU Supply Agreement”) to define general forecast, order, supply and payment terms for Astellas to purchase roxadustat bulk drug product from FibroGen in support of commercial supplies. The related drug product revenue, as described under Drug Product Revenue section below, was $ 1.1 million for the three and six months ended June 30, 2022, respectively. There was no related drug product revenue for the three and six months ended June 30, 2021. AstraZeneca Agreements U.S./Rest of World (“RoW”) Agreement Effective July 30, 2013, the Company entered into a collaboration agreement with AstraZeneca AB ("AstraZeneca") for the development and commercialization of roxadustat for the treatment of anemia in the U.S. and all other countries in the world, other than China, not previously licensed under the Astellas Europe and Astellas Japan Agreements (“U.S./RoW Agreement”). It also excludes China, which is covered by a separate agreement with AstraZeneca described below. Under the terms of the U.S./RoW Agreement, AstraZeneca agreed to pay upfront, non-contingent, non-refundable and time-based payments, and potential milestone payments, totaling $ 1.2 billion . AstraZeneca will pay the Comp any tiered royalty payments on AstraZeneca’s future net sales (as defined in the agreement) of roxadustat in the low 20% range . In addition, the Company will receive a transfer price for shipment of commercial product based on a percentage of AstraZeneca’s net sales (as defined in the agreement) in the low- to mid-single digit range. The aggregate amount of consideration received under the U.S./RoW Agreement through June 30, 2022 totaled $ 439.0 million , excluding drug product revenue that is discussed separately below. While FibroGen and AstraZeneca continue to develop roxadustat in the U.S. for the treatment of anemia in patients with myelodysplastic syndromes, the Company has not been able to agree on a path forward for AstraZeneca to fund further roxadustat development for CKD anemia in the U.S. Therefore, the Company does not expect to receive most or all of the remaining U.S./RoW Agreement milestones from AstraZeneca. In 2020, the Company entered into Master Supply Agreement under the U.S./RoW Agreement with AstraZeneca (“Master Supply Agreement”) to define general forecast, order, supply and payment terms for AstraZeneca to purchase roxadustat bulk drug product from FibroGen in support of commercial supplies. There was no related drug product revenue for the three and six months ended June 30, 2022, and the related drug product revenue was $( 6.7 ) million and $( 2.2 ) million for the three and six months ended June 30, 2021, respectively. See Drug Product Revenue section below. China Agreement Effective July 30, 2013, the Company (through its subsidiaries affiliated with China) entered into the China Agreement (“China Agreement”). Under the terms of the China Agreement, AstraZeneca agreed to pay upfront consideration and potential milestone payments, totaling $ 376.7 million . The China Agreement is structured as a 50/50 profit or loss share (as defined), which was amended under the China Amendment discussed below in 2020, and provides for joint development costs (including capital and equipment costs for construction of the manufacturing plant in China), to be shared equally during the development period. The aggregate amount of such consideration received for milestone and upfront payments through June 30, 2022 totaled $ 77.2 million . China Amendment In July 2020, FibroGen China Anemia Holdings, Ltd., FibroGen (China) Medical Technology Development Co., Ltd. ("FibroGen Beijing"), and FibroGen International (Hong Kong) Limited (collectively “FibroGen China”) and AstraZeneca entered into the China Amendment, relating to the development and commercialization of roxadustat in China. Under the China Amendment, in September 2020, FibroGen Beijing and AstraZeneca completed the establishment of a jointly owned entity, Beijing Falikang Pharmaceutical Co., Ltd. ("Falikang"), which performs roxadustat distribution, as well as conducts sales and marketing through AstraZeneca. Since Falikang became fully operational in January 2021, substantially all direct roxadustat product sales to distributors in China are made by Falikang, while FibroGen Beijing continues to sell roxadustat product directly in one province in China. FibroGen Beijing manufactures and supplies commercial product to Falikang based on a gross transfer price, which is adjusted for the estimated profit share. Amounts recognized as revenue under the U.S./RoW Agreement and China Agreement with AstraZeneca were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 U.S. / RoW License revenue $ — $ — $ — $ — Development revenue 3,352 16,993 9,171 27,969 The transaction price relat ed to consideration received and accounts receivable has been allocated to each of the following performance obligations under the U.S./RoW Agreement and China Agreement with AstraZeneca, along with any associated deferred revenue as follows (in thousands): U.S. / RoW and China Agreements Cumulative Deferred Total License $ 341,844 $ — $ 341,844 Co-development, information sharing & 612,290 — 612,290 China performance obligation * 71,527 170,514 242,041 Total license and development revenue $ 1,025,661 $ 170,514 ** $ 1,196,175 * China performance obligation revenue is recognized as product revenue, as described under Product Revenue, Net section below. ** Contract assets and liabilities related to rights and obligations in the same contract are recorded net on the consolidated balance sheets. As of June 30, 2022, deferred revenue included $ 157.3 million related to the U.S./RoW Agreement and China Agreement, which represents the net of $ 170.5 million of deferred revenue presented above and a $ 13.2 million unbilled co-development revenue under the China Amendment with AstraZeneca. There was no revenue resulting from changes to estimated variable consideration in the current period relating to performance obligations satisfied or partially satisfied in previous periods for the three months ended June 30, 2022 under the U.S./RoW Agreement. The remainder of the transaction price related to the U.S./R oW Agreement and China Agreement includes $ 18.0 million of variable consideration from estimated future co-development billing and is estimated to be recognized over the remaining development service period, except for amounts allocated to the China performance obligation. The amount allocated to the China performance obligation is expected to be recognized as the Company transfers control of the commercial drug product to Falikang. The net product revenue from the sales to Falikang was $ 19.7 million and $ 11.8 million for the three months ended June 30, 2022 and 2021, and $ 36.0 million and $ 22.2 million for the six months ended June 30, 2022 and 2021, respectively, as described under Product Revenue, Net section below. In addition to sales to Falikang, the net product revenue from direct sales distributors in China was $ 3.5 million and $ 1.6 million for the three months ended June 30, 2022 and 2021, and $ 6.2 million and $ 6.6 million for the six months ended June 30, 2022 and 2021, respectively, as described as direct sales under Product Revenue, Net section below. Product Revenue, Net Product revenue, net from the sales of roxadustat commercial product in China was as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Direct Sales: Gross revenue $ 3,533 $ 2,230 $ 6,362 $ 7,659 Discounts and rebates ( 13 ) ( 618 ) ( 187 ) ( 1,181 ) Sales returns ( 1 ) ( 1 ) 3 88 Direct sales revenue, net 3,519 1,611 6,178 6,566 Sales to Falikang: Gross transaction price 28,281 26,714 51,007 51,115 Profit share ( 10,065 ) ( 9,573 ) ( 18,914 ) ( 19,636 ) Net transaction price 18,216 17,141 32,093 31,479 Decrease (increase) in deferred revenue 1,521 ( 5,381 ) 3,866 ( 9,312 ) Sales to Falikang revenue, net 19,737 11,760 35,959 22,167 Total product revenue, net $ 23,256 $ 13,371 $ 42,137 $ 28,733 Direct Sales Product revenue from direct roxadustat product sales to distributors in China is recognized in an amount that reflects the consideration that the Company expects to be entitled to in exchange for those products, net of various sales rebates and discounts. The total discounts and rebates were immaterial for the periods presented. Due to the Company’s legal right to offset, at each balance sheet date, the rebates and discounts are presented as reductions to gross accounts receivable from the distributor, or as a current liability to the distributor to the extent that the total amount exceeds the gross accounts receivable or when the Company expects to settle the discount in cash. The Company’s legal right to offset is calculated at the individual distributor level. The following table includes a roll-forward of the contract liabilities (in thousands): Balance at Additions Deduction Currency Balance at Product revenue - Direct sales - contract liabilities $ ( 3,176 ) $ ( 286 ) $ 1,903 $ 157 $ ( 1,402 ) The above contract liabilities were included in accrued and other current liabilities in the condensed consolidated balance sheet. The rebates and discounts reflected as reductions to gross accounts receivable for direct sales wer e $ 0.7 million and $ 1.1 million a s of June 30, 2022 and December 31, 2021, respectively. Sales to Falikang – China Performance Obligation Since Falikang became fully operational in January 2021, substantially all direct roxadustat product sales to distributors in China are made by Falikang. FibroGen Beijing manufactures and supplies commercial product to Falikang. The net transfer price for FibroGen Beijing’s product sales to Falikang is based on a gross transfer price, which is adjusted to account for the 50/50 profit share for the period. The roxadustat sales to Falikang marked the beginning of the Company’s China performance obligation under the Company’s agreements with AstraZeneca . Product revenue is based on the transaction price of the China performance obligation. Revenue is recognized when control of the product is transferred to Falikang, in an amount that reflects the allocation of the transaction price to the performance obligation satisfied during the reporting period. Any net transaction price in excess of the revenue recognized is added to the deferred balance to date, and will be recognized over future periods as the performance obligation is satisfied. Following updates to its estimates, the Company recognized $ 1.5 million and $ 3.9 million from the previously deferred revenue of the China performance obligation during the three and six months ended June 30, 2022, respectively. The following table includes a roll-forward of the related deferred revenue that is considered as a contract liability (in thousands): Balance at Additions Recognized as Revenue Currency Balance at Product revenue - AstraZeneca China $ ( 171,516 ) $ ( 36,184 ) $ 35,959 $ 1,227 $ ( 170,514 ) Deferred revenue includes amounts allocated to the China performance obligation under the AstraZeneca arrangement as revenue recognition associated with this unit of accounting is tied to the commercial launch of the products within China and to when the control of the manufactured commercial products is transferred to AstraZeneca. As of June 30, 2022 , approximately $ 14.9 million of the above deferred revenue related to the China unit of accounting was included in short-term deferred revenue, which represents the amount of deferred revenue associated with the China unit of accounting that is expected to be recognized within the next 12 months, associated with the commercial sales in China. Due to the Company’s legal right to offset, at each balance sheet date, the rebates and discounts, mainly related to profit sharing, are presented as reductions to gross accounts receivable from Falikang, which was $ 6.5 million and $ 13.4 million as of June 30, 2022 and December 31, 2021 , respectively. Drug Product Revenue Drug product revenue from commercial-grade active pharmaceutical ingredient (“API”) or bulk drug product sales to Astellas and AstraZeneca was as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Astellas - Japan Agreement $ 17 $ ( 1,974 ) $ 7,611 $ 2,056 Astellas - Europe Agreement 1,076 — 1,076 — AstraZeneca - U.S. Agreement — ( 6,674 ) — ( 2,224 ) Drug product revenue $ 1,093 $ ( 8,648 ) $ 8,687 $ ( 168 ) During the first quarter of 2022, the Company fulfilled a shipment obligation under the terms of Japan Amendment with Astellas, and recognized related drug product revenue of $ 9.8 million in the same period. In addition, the Company updated its estimate of variable consideration related to the API shipments fulfilled under the terms of Japan Amendment with Astellas, and accordingly recorded adjustments to the drug product revenue of $( 2.2 ) million, $( 2.0 ) million and $ 4.0 million for the first quarter of 2022, the second quarter of 2021 and the first quarter of 2021, respectively. Specifically, the change in estimated variable consideration was based on the API held by Astellas at period end, adjusted to reflect the changes in the estimated bulk product strength mix intended to be manufactured by Astellas, estimated cost to convert the API to bulk product tablets, and estimated yield from the manufacture of bulk product tablets, among others. During the second quarter of 2022, the Company transferred bulk drug product for commercial purposes under the terms of the Europe Agreement and the EU Supply Agreement with Astellas, and recognized the related fully burdened manufacturing costs of $ 1.0 million as drug product revenue, and recorded $ 23.2 million as deferred revenue due to a high degree of uncertainty associated with the final consideration. In addition, the Company recognized royalty revenue of $ 0.1 million as drug product revenue from the deferred revenue under the Europe Agreement during the second quar ter of 2022. The remainder of the deferred revenue will be recognized as and when uncertainty is resolved, based on the performance of roxadustat product sales in the territory. During the first quarter of 2022, the Company billed and received $ 49.2 million from Astellas related to the annual transfer price true up for bulk drug product transferred for commercial purposes. This amount was recorded in deferred revenue and netted against an unbilled contract asset as of December 31, 2021. During the first and second quarter of 2022, the Company updated its estimate of variable consideration related to the bulk drug product transferred in prior years. Specifically, the change in estimated variable consideration was based on the bulk drug product held by Astellas at the period end, adjusted to reflect the changes in the estimated transfer price, forecast information, shelf-life estimates and other items. As a result, the Company reclassified $ 43.3 million from deferred revenue to accrued liabilities as of June 30, 2022, representing its best estimate that this amount will be paid in the first quarter of 2023. During the first quarter of 2022, the Company evaluated the current developments in the U.S. market, and updated its estimates of variable consideration associated with bulk drug product shipments to AstraZeneca in prior years as commercial supply. As a result, the Company reclassified $ 11.2 million from the related deferred revenue to accrued liabilities as of June 30, 2022. The following table includes a roll-forward of the above-mentioned deferred revenues that are considered as contract liabilities related to drug product (in thousands): Balance at Additions Recognized as Revenue Reclassified to Accrued Liability / Accounts Payable Balance at Astellas - Japan Agreement $ ( 1,974 ) $ ( 2,226 ) $ — $ 4,200 $ — Astellas - Europe Agreement ( 25,891 ) ( 72,409 ) 90 43,273 ( 54,937 ) AstraZeneca - U.S. Agreement ( 11,171 ) — — 11,171 — Drug product revenue - deferred revenue $ ( 39,036 ) $ ( 74,635 ) $ 90 $ 58,644 $ ( 54,937 ) Eluminex Agreement In July 2021, FibroGen exclusively licensed to Eluminex Biosciences (Suzhou) Limited (“Eluminex”) global rights to its investigational biosynthetic cornea derived from recombinant human collagen Type III. Under the terms of the agreement with Eluminex , as amended and restated on January 21, 2022, Eluminex made an $ 8.0 million upfront payment to FibroGen during the first quarter of 2022, which was recorded as an unbilled contract asset as of December 31, 2021 in the prepaid expenses and other current assets in the condensed consolidated balance sheets. In addition, FibroGen may receive up to a total of $ 64.0 million in future manufacturing, clinical, regulatory, and commercial milestone payments for the biosynthetic cornea program, as well as $ 36.0 million in commercial milestones for the first recombinant collagen III product that is not the biosynthetic cornea. FibroGen will also be eligible to receive mid single-digit to low double-digit royalties based upon worldwide net sales of cornea products, and low single-digit to mid single-digit royalties based upon worldwide n et sales of other recombinant human collagen type III products that are not cornea products. During the first quarter of 2022, FibroGen and Eluminex entered into a separate contract manufacturing agreement, under which the Company is responsible for supplying the cornea product at 110 % of its product manufacturing costs until its manufacturing technology is fully transferred to Eluminex. The related contract manufacturing revenue was recorded as other revenue and included in development and other revenue in the condensed consolidated statement of operations. Amounts recognized as revenue under the Eluminex were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 Eluminex Other revenue - contract manufacturing $ 280 $ — $ 1,042 $ —

Variable Interest Entity

Variable Interest Entity	6 Months Ended
	Jun. 30, 2022
Acquisition And Variable Interest Entity [Abstract]
Variable Interest Entity	3. Variable Interest Entity Falikang is a distribution entity jointly owned by AstraZeneca and FibroGen Beijing. FibroGen Beijing owns 51.1 % of the outstanding shares of Falikang. Pursuant to the guidance under ASC 810, Consolidation (“ASC 810”), the Company concluded that Falikang qualifies as a VIE. As Falikang is a distribution entity and AstraZeneca is the final decision maker for all the roxadustat commercialization activities, the Company lacks the power criterion, while AstraZeneca meets both the power and economic criteria under the ASC 810 to direct the activities of Falikang that most significantly impact its performance. Therefore, the Company is not the primary beneficiary of this VIE for accounting purposes. As a result, the Company accounts for its investment in Falikang under the equity method, and Falikang is not consolidated into the Company’s condensed consolidated financial statements. The Company records its total investments in Falikang as an equity method investment in an unconsolidated VIE in the condensed consolidated balance sheet. In addition, the Company recognizes its proportionate share of the reported profits or losses of Falikang as investment gain or loss in unconsolidated VIE in the condensed consolidated statement of operations and as an adjustment to its investment in Falikang in the condensed consolidated balance sheet. Falikang has not incurred material profit or loss to date. The Company may provide shareholder loans to Falikang to meet necessary financial obligations as part of its operations. To date, these loans have been immaterial. The Company’s equity method investment in Falikang was as follows (in thousands): Entity Ownership Percentage Balance at Share of Net Income Currency Balance at Falikang 51.1 % $ 3,825 $ 885 $ ( 216 ) $ 4,494 Falikang is considered a related party to the Company. See Note 7, Related Party Transactions , for related disclosures.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The fair values of the Company’s financial assets that are measured on a recurring basis are as follows (in thousands): June 30, 2022 Level 1 Level 2 Level 3 Total Money market funds $ 34,123 $ — $ — $ 34,123 Corporate bonds — 125,491 — 125,491 Commercial paper — 55,307 — 55,307 U.S. government bonds 105,383 10,972 — 116,355 Agency bonds — 14,930 — 14,930 Asset-backed securities — 4,741 — 4,741 Foreign government bonds — 4,954 — 4,954 Total $ 139,506 $ 216,395 $ — $ 355,901 December 31, 2021 Level 1 Level 2 Level 3 Total Money market funds $ 58,801 $ — $ — $ 58,801 Corporate bonds — 182,646 — 182,646 Commercial paper — 69,079 — 69,079 U.S. government bonds 91,522 — — 91,522 Agency bonds — 23,275 — 23,275 Asset-backed securities — 27,087 — 27,087 Foreign government bonds — 9,154 — 9,154 Total $ 150,323 $ 311,241 $ — $ 461,564 The Company’s Level 2 investments are valued using third-party pricing sources. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar investments, issuer credit spreads, benchmark investments, prepayment/default projections based on historical data, and other observable inputs. There were no transfers of assets between levels during the three and six months ended June 30, 2022 .

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	5. Balance Sheet Components Cash and Cash Equivalents Cash and cash equivalents consisted of the following (in thousands): June 30, 2022 December 31, 2021 Cash $ 128,152 $ 111,422 Commercial paper 5,483 1,000 Money market funds 34,123 58,801 Total cash and cash equivalents $ 167,758 $ 171,223 At June 30, 2022 and December 31, 2021 , a total of $ 98.8 million and $ 91.2 million, respectively, of the Company’s cash and cash equivalents were held outside of the U.S. in its foreign subsidiaries to be used primarily for its China operations. Investments The Company’s investments consist of available-for-sale debt investments and marketable equity investments. The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s investments by major investments type are summarized in the tables below (in thousands): June 30, 2022 Amortized Cost Gross Unrealized Gross Unrealized Fair Value Corporate bonds $ 127,387 $ — $ ( 1,896 ) $ 125,491 Commercial paper 49,824 — — 49,824 U.S. government bonds 118,142 — ( 1,787 ) 116,355 Agency bonds 15,235 — ( 305 ) 14,930 Asset-backed securities 4,751 — ( 10 ) 4,741 Foreign government bonds 5,032 — ( 78 ) 4,954 Total investments $ 320,371 $ — $ ( 4,076 ) $ 316,295 December 31, 2021 Amortized Cost Gross Unrealized Gross Unrealized Fair Value Corporate bonds $ 183,136 $ 2 $ ( 492 ) $ 182,646 Commercial paper 68,079 — — 68,079 U.S. government bonds 91,840 — ( 318 ) 91,522 Agency bonds 23,339 — ( 64 ) 23,275 Asset-backed securities 27,105 — ( 18 ) 27,087 Foreign government bonds 9,165 — ( 11 ) 9,154 Total investments $ 402,664 $ 2 $ ( 903 ) $ 401,763 At June 30, 2022 , the available-for-sale investments had contractual maturities range from several months to two years . The Company periodically reviews its available-for-sale investments for other-than-temporary impairment. The Company considers factors such as the duration, severity and the reason for the decline in value, the potential recovery period and its intent to sell. For debt securities, the Company also considers whether (i) it is more likely than not that the Company will be required to sell the debt securities before recovery of their amortized cost basis, and (ii) the amortized cost basis cannot be recovered as a result of credit losses. Based on the results of its review, the Company did no t recognize any other-than-temporary impairment loss during the three and six months ended June 30, 2022 and 2021. Inventories Inventories consisted of the following (in thousands): June 30, 2022 December 31, 2021 Raw materials $ 1,220 $ 1,363 Work-in-progress 34,488 21,499 Finished goods 5,191 8,153 Total inventories $ 40,899 $ 31,015 Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following (in thousands): June 30, 2022 December 31, 2021 Preclinical and clinical trial accruals $ 66,553 $ 56,283 API and bulk drug product price true-up 54,443 — Acquired in-process research and development asset — 35,000 Payroll and related accruals 13,480 20,909 Accrued co-promotion expenses - current 32,352 25,746 Contract liabilities to pharmaceutical distributors 1,402 3,176 Roxadustat profit share to AstraZeneca 7,497 7,895 Property taxes and other taxes 5,449 12,610 Professional services 4,929 6,074 Other 6,994 4,906 Total accrued and other current liabilities $ 193,099 $ 172,599 The accrued liabilities of $ 54.4 million for API and bulk drug product price true-up as of June 30, 2022 resulted from changes in estimated variable consideration associated with the API shipments fulfilled under the terms of the Japan Amendment with Astellas, the bulk drug product transferred under the terms of the Europe Agreement and the EU Supply Agreement with Astellas, and the bulk drug product shipments to AstraZeneca under the terms of the Master Supply Agreement. See Note 2, Collaboration Agreements, License Agreement and Revenues, for details. The acquired in-process research and development asset of $ 35.0 million as of December 31, 2021 was related to the upfront payment under an exclusive license and option agreement with HiFiBiO Therapeutics (“HiFiBiO”), which was paid during the six months ended June 30, 2022 .

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	6. Income Taxes Provisions for (benefit from) income tax for the three and six months ended June 30, 2022 and 2021 were primarily due to foreign taxes. Based upon the weight of available evidence, which includes its historical operating performance, reported cumulative net losses since inception, the Company has established and continues to maintain a full valuation allowance against its net deferred tax assets as it does not currently believe that realization of those assets is more likely than not.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	7. Related Party Transactions Astellas is an equity investor in the Company and is considered a related party. The Company recorded revenue related to collaboration agreements with Astellas of $ 1.8 million and $ 2.6 million for the three months ended June 30, 2022 and 2021 , and $ 29.6 million and $ 6.3 million for the six months ended June 30, 2022 and 2021 , respectively. The Company also recorded drug product revenue from Astellas of $ 1.1 million and $( 2.0 ) million for the three months ended June 30, 2022 and 2021, and $ 8.7 million and $ 2.1 million for the six months ended June 30, 2022 and 2021, respectively. See Note 2, Collaboration Agreements, License Agreement and Revenues , for details. The Company’s expense related to collaboration agreements with Astellas was immaterial for each of the three and six months ended June 30, 2022 and 2021. As of June 30, 2022 and December 31, 2021 , accounts receivable from Astellas were $ 26.1 million and $ 10.9 million, respectively. As of June 30, 2022 and December 31, 2021 , total deferred revenue from Astellas was $ 54.9 million and $ 27.9 million, respectively. As of June 30, 2022 , the amount due to Astellas was $ 43.3 million. As of December 31, 2021, amount due to Astellas was immaterial. Falikang, an entity jointly owned by FibroGen Beijing and AstraZeneca is an unconsolidated VIE accounted for as an equity method investment, and considered as a related party to the Company. FibroGen Beijing owns 51.1 % of Falikang’s equity. See Note 3, Variable Interest Entity , for details. The net product revenue from Falikang was $ 19.7 million and $ 11.8 million for the three months ended June 30, 2022 and 2021, and $ 36.0 million and $ 22.2 million for the six months ended June 30, 2022 and 2021, respectively. See Note 2, Collaboration Agreements, License Agreement and Revenues , for details. The investment income in Falikang was $ 0.6 million for each of the three months ended June 30, 2022 and 2021, and $ 0.9 million and $ 0.3 million for the six months ended June 30, 2022 and 2021, respectively. As of June 30, 2022 and December 31, 2021, the Company’s equity method investment in Falikang was $ 4.5 million and $ 3.8 million , respectively. See Note 3, Variable Interest Entity , for details. As of June 30, 2022 , accounts receivable, net, from Falikang was of $ 0.7 million. As of December 31, 2021 , accounts receivable, net, from Falikang was zero . The total deferred revenue from Falikang was zero as of June 30, 2022 . The total deferred revenue from Falikang was $ 1.2 million as of December 31, 2021 .

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Contract Obligations As of June 30, 2022, the Company had $ 94.1 million of operating lease liabilities. As of June 30, 2022 , the Company had outstanding total non-cancelable purchase obligations of $ 57.7 million, including $ 33.2 million for manufacture and supply of pamrevlumab, $ 9.2 million for manufacture and supply of roxadustat, and $ 15.3 million for other purchases and programs. The Company expects to fulfill its commitments under these agreements in the normal course of business, and as such, no liability has been recorded. Some of the Company’s license agreements provide for periodic maintenance fees over specified time periods, as well as payments by the Company upon the achievement of development, regulatory and commercial milestones. As of June 30, 2022 , future milestone payments for research and preclinical stage development programs consisted of up to approximately $ 697.9 million in total potential future milestone payments under the Company’s license agreements with HiFiBiO (for Gal-9 and CCR8), Medarex, Inc. and others. These milestone payments generally become due and payable only upon the achievement of certain developmental, clinical, regulatory and/or commercial milestones. The event triggering such payment or obligation has not yet occurred. Legal Proceedings and Other Matters From time to time, the Company is a party to various legal actions, both inside and outside the U.S., arising in the ordinary course of its business or otherwise. The Company accrues amounts, to the extent they can be reasonably estimated, that the Company believes will result in a probable loss (including, among other things, probable settlement value) to adequately address any liabilities related to legal proceedings and other loss contingencies. A loss or a range of loss is disclosed when it is reasonably possible that a material loss will incur and can be estimated, or when it is reasonably possible that the amount of a loss, when material, will exceed the recorded provision. The Company did not have any material accruals for any active legal action in its condensed consolidated balance sheets as of June 30, 2022, as the Company could not predict the ultimate outcome of these matters, or reasonably estimate the potential exposure. In April 2021, three putative securities class action complaints were filed against FibroGen and certain of its current and former executive officers (collectively, the “Defendants”) in the U.S. District Court for the Northern District of California. The lawsuits allege that Defendants violated the Securities Exchange Act of 1934 by making materially false and misleading statements regarding FibroGen’s Phase 3 clinical studies data and prospects for U.S. Food and Drug Administration approval between November 2019 and December 2020. Plaintiffs seek to represent a class of persons or entities that purchased FibroGen securities between November 8, 2019 and April 6, 2021. In May 2021, two additional putative securities class action complaints were filed against Defendants alleging the same claims. One of the lawsuits alleges that Defendants made materially false and misleading statements between October 2017 and December 2020 and seeks to represent a class of persons or entities that purchased FibroGen securities between October 18, 2017 and April 6, 2021. The other lawsuit alleges that Defendants made materially false and misleading statements between December 2018 and February 2020 and seeks to represent a class of persons or entities that purchased FibroGen securities between December 20, 2018 and April 6, 2021. All plaintiffs seek unspecified monetary damages and other relief. On August 30, 2021, the Court consolidated the actions and appointed a group of lead plaintiffs. Plaintiffs filed their consolidated amended complaint on October 29, 2021 and a corrected consolidated amended complaint on November 19, 2021 (the “Complaint”). The Complaint alleges false and misleading statements between December 2018 and June 2021 and seeks to represent a class of persons or entities that purchased FibroGen securities between December 20, 2018 and July 15, 2021. Defendants filed motions to dismiss the Complaint on January 14, 2022. Plaintiffs’ opposition to Defendants’ motions to dismiss was due March 4, 2022 and Defendants’ reply briefs were due April 8, 2022. On July 15, 2022, the court issued an order denying Defendants’ motions to dismiss. Defendants’ answer to the Complaint is due September 13, 2022. On July 30, 2021, a purported shareholder derivative complaint was filed in the U.S. District Court for the Northern District of California. The complaint names as defendants ten of FibroGen’s current and former officers and directors, as well as FibroGen as nominal defendant, and asserts state and federal claims based on some of the same alleged misstatements as the securities class action complaint. The complaint seeks unspecified damages, attorneys’ fees, and other costs. The action remains stayed at this time. On December 27, 2021, a second purported shareholder derivative complaint was filed in the U.S. District Court for the District of Delaware. The complaint names seventeen of FibroGen’s current and former officers and directors as defendants, as well as FibroGen as nominal defendant, and asserts state and federal claims based on some of the same alleged misstatements as the securities class action complaint, as well as allegations of insider trading against certain defendants. The complaint seeks unspecified damages, attorneys’ fees, and other costs. The action remains stayed at this time. On April 14, 2022, a third purported shareholder derivative complaint was filed in the Delaware Court of Chancery. It names the same defendants as the second purported shareholder derivative action and asserts similar claims based upon similar allegations. The complaint seeks unspecified damages, attorneys’ fees, and other costs. Defendants have not been served in the third action. The Company believes that the claims are without merit and it intends to vigorously defend against them. However, any litigation is inherently uncertain, and any judgment or injunctive relief entered against FibroGen or any adverse settlement could materially and adversely impact its business, results of operations, financial condition, and prospects. In the fourth quarter of 2021, the Company received a subpoena from the SEC requesting documents related to roxadustat’s pooled cardiovascular safety data. The Company is fully cooperating with the SEC. The Company cannot predict with any degree of certainty the outcome of the SEC’s investigation or determine the extent of any potential liabilities. The Company also cannot predict whether there will be any loss as a result of the investigation nor can it provide an estimate of the possible loss or range of loss. Any adverse outcome in this matter or any related proceeding could expose the Company to substantial damages, penalties, or reputational harm that may have a material adverse impact on the Company’s business, results of operations, financial condition, growth prospects, and price of its common stock. On August 3, 2022, the Company's Board of Directors received two litigation demands from purported shareholders of the Company, asking the Board of Directors to investigate and take action against certain current and former officers and directors of the Company for alleged wrongdoing based on the same allegations in the pending derivative and securities class action lawsuits. The Company may in the future receive such additional demands. Indemnification Agreements The Company enters into standard indemnification arrangements in the ordinary course of business, including for example, service, manufacturing and collaboration agreements. Pursuant to these arrangements, the Company indemnifies, holds harmless, and agrees to reimburse the indemnified parties for losses suffered or incurred by the indemnified party, including in connection with intellectual property infringement claims by any third party with respect to its technology. The term of these indemnification agreements is generally perpetual any time after the execution of the agreement. The Company has entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the extent permissible under applicable law. The maximum potential amount of future payments the Company could be required to make under these arrangements is not determinable. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. As a result, the Company believes the estimated fair value of these arrangements is minimal.

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Event	9. Subsequent Event On July 26, 2022, the Company received a written evidence from China’s State Taxation Administration, which confirms the transfer of certain intellectual property rights in 2020 relating to the Company’s Chinese business between its wholly owned subsidiaries is exempted from value added tax (“VAT”). The Company evaluated this subsequent event and concluded that it required adjustment and disclosure in the condensed consolidated financial statements. Specifically, the Company released the previously accrued input VAT and output VAT (with a zero net impact to the condensed consolidated balance sheet), the related VAT surcharge, and the estimated late payment fees. As a result, for the three months ended June 30, 2022, the Company recorded a reduction of $ 8.2 million to the accrued and other current liabilities, and a reduction of $ 2.3 million to the other assets in the condensed consolidated balance sheet, and a reduction of $ 6.0 million to other expenses in the condensed consolidated statement of operations.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Description of Operations	Description of Operations FibroGen, Inc. (“FibroGen” or the “Company”) is headquartered in San Francisco, California, with subsidiary offices in Beijing and Shanghai, People’s Republic of China (“China”). FibroGen is a leading biopharmaceutical company developing and commercializing a pipeline of first-in-class therapeutics. The Company applies its pioneering expertise in hypoxia-inducible factor ("HIF") biology, 2-oxoglutarate enzymology, and connective tissue growth factor to advance innovative medicines for the treatment of anemia, fibrotic disease, and cancer. Pamrevlumab, a human monoclonal antibody targeting connective tissue growth factor, is in Phase 3 clinical development for the treatment of idiopathic pulmonary fibrosis, locally advanced unresectable pancreatic cancer and Duchenne muscular dystrophy. To date, the Company has retained exclusive worldwide rights for pamrevlumab. Roxadustat is an oral small molecule inhibitor of HIF prolyl hydroxylase (“HIF-PH”) activity. Roxadustat (爱瑞卓 ® , EVRENZO TM ) is now approved in China, Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (“CKD”) patients on dialysis and those not on dialysis. Astellas Pharma Inc. (“Astellas”) and FibroGen are collaborating on the development and commercialization of roxadustat for the potential treatment of anemia in territories including Japan, Europe, Turkey, Russia and the Commonwealth of Independent States, the Middle East, and South Africa. FibroGen and AstraZeneca are collaborating on the development and commercialization of roxadustat for the potential treatment of anemia in the U.S., China, other markets in the Americas, Australia/New Zealand, and Southeast Asia. Roxadustat is in Phase 3 clinical development for anemia associated with myelodysplastic syndromes. The Company has completed a Phase 2 study of roxadustat in chemotherapy-induced anemia and is running a Phase 3 trial of roxadustat chemotherapy-induced anemia in China. The Company has a pipeline of late-stage clinical programs as well as preclinical drug candidates at various stages of development that include both small molecules and biologics. The Company has leveraged its internally developed 2-oxoglutarate and connective tissue growth factor biology expertise as well as in-licensing of additional programs, such as antibodies targeting Galectin-9 protein (“Gal-9”) and C-C Motif Chemokine Receptor 8 (“CCR8”), to further enhance its late-stage preclinical pipeline. FibroGen's goal is to build a diversified pipeline with novel drugs that will address unmet patient needs in oncology, immunology, and fibrosis.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The condensed consolidated financial statements include the accounts of FibroGen, its wholly-owned subsidiaries and its majority-owned subsidiaries, FibroGen Europe Oy and FibroGen China Anemia Holdings, Ltd. All inter-company transactions and balances have been eliminated in consolidation. For the variable interest entity (“VIE”) for which FibroGen is not the primary beneficiary, the Company uses the equity method of accounting. The Company operates as one reportable segment — the discovery, development and commercialization of novel therapeutics to treat serious unmet medical needs. The unaudited condensed consolidated financial statements and related disclosures have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) applicable to interim financial reporting and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the U.S. Securities and Exchange Commission (“SEC”) and, therefore, do not include all information and footnote disclosures normally included in the annual consolidated financial statements. The financial information included herein should be read in conjunction with the consolidated financial statements and related notes in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed on February 28, 2022 and as amended on March 4, 2022 (“2021 Form 10-K”). Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no impact on previously reported financial position, results of operations, or cash flows.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions include valuation and recognition of revenue and deferred revenue, specifically, estimates in variable consideration for drug product sales, and estimates in transaction price per unit for the China manufacturing and supply obligation. On an ongoing basis, management reviews these estimates and assumptions. Changes in facts and circumstances may alter such estimates and actual results could differ from those estimates. In the Company’s opinion, the accompanying unaudited condensed consolidated financial statements include all normal recurring adjustments necessary for a fair statement of its financial position, results of operations and cash flows for the interim periods presented.
Significant Accounting Policies	1. Significant Accounting Policies Description of Operations FibroGen, Inc. (“FibroGen” or the “Company”) is headquartered in San Francisco, California, with subsidiary offices in Beijing and Shanghai, People’s Republic of China (“China”). FibroGen is a leading biopharmaceutical company developing and commercializing a pipeline of first-in-class therapeutics. The Company applies its pioneering expertise in hypoxia-inducible factor ("HIF") biology, 2-oxoglutarate enzymology, and connective tissue growth factor to advance innovative medicines for the treatment of anemia, fibrotic disease, and cancer. Pamrevlumab, a human monoclonal antibody targeting connective tissue growth factor, is in Phase 3 clinical development for the treatment of idiopathic pulmonary fibrosis, locally advanced unresectable pancreatic cancer and Duchenne muscular dystrophy. To date, the Company has retained exclusive worldwide rights for pamrevlumab. Roxadustat is an oral small molecule inhibitor of HIF prolyl hydroxylase (“HIF-PH”) activity. Roxadustat (爱瑞卓 ® , EVRENZO TM ) is now approved in China, Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (“CKD”) patients on dialysis and those not on dialysis. Astellas Pharma Inc. (“Astellas”) and FibroGen are collaborating on the development and commercialization of roxadustat for the potential treatment of anemia in territories including Japan, Europe, Turkey, Russia and the Commonwealth of Independent States, the Middle East, and South Africa. FibroGen and AstraZeneca are collaborating on the development and commercialization of roxadustat for the potential treatment of anemia in the U.S., China, other markets in the Americas, Australia/New Zealand, and Southeast Asia. Roxadustat is in Phase 3 clinical development for anemia associated with myelodysplastic syndromes. The Company has completed a Phase 2 study of roxadustat in chemotherapy-induced anemia and is running a Phase 3 trial of roxadustat chemotherapy-induced anemia in China. The Company has a pipeline of late-stage clinical programs as well as preclinical drug candidates at various stages of development that include both small molecules and biologics. The Company has leveraged its internally developed 2-oxoglutarate and connective tissue growth factor biology expertise as well as in-licensing of additional programs, such as antibodies targeting Galectin-9 protein (“Gal-9”) and C-C Motif Chemokine Receptor 8 (“CCR8”), to further enhance its late-stage preclinical pipeline. FibroGen's goal is to build a diversified pipeline with novel drugs that will address unmet patient needs in oncology, immunology, and fibrosis. Basis of Presentation and Principles of Consolidation The condensed consolidated financial statements include the accounts of FibroGen, its wholly-owned subsidiaries and its majority-owned subsidiaries, FibroGen Europe Oy and FibroGen China Anemia Holdings, Ltd. All inter-company transactions and balances have been eliminated in consolidation. For the variable interest entity (“VIE”) for which FibroGen is not the primary beneficiary, the Company uses the equity method of accounting. The Company operates as one reportable segment — the discovery, development and commercialization of novel therapeutics to treat serious unmet medical needs. The unaudited condensed consolidated financial statements and related disclosures have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) applicable to interim financial reporting and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the U.S. Securities and Exchange Commission (“SEC”) and, therefore, do not include all information and footnote disclosures normally included in the annual consolidated financial statements. The financial information included herein should be read in conjunction with the consolidated financial statements and related notes in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed on February 28, 2022 and as amended on March 4, 2022 (“2021 Form 10-K”). Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no impact on previously reported financial position, results of operations, or cash flows. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions include valuation and recognition of revenue and deferred revenue, specifically, estimates in variable consideration for drug product sales, and estimates in transaction price per unit for the China manufacturing and supply obligation. On an ongoing basis, management reviews these estimates and assumptions. Changes in facts and circumstances may alter such estimates and actual results could differ from those estimates. In the Company’s opinion, the accompanying unaudited condensed consolidated financial statements include all normal recurring adjustments necessary for a fair statement of its financial position, results of operations and cash flows for the interim periods presented. Significant Accounting Policies The accounting policies used by the Company in its presentation of interim financial results are consistent with those presented in Note 2 to the consolidated financial statements included in the 2021 Form 10-K, except for the updates to the following: Stock-Based Compensation The Company maintains equity incentive plans under which incentive and nonqualified stock options are granted to employees, which are comprised of stock options, service-based restricted stock units ("RSUs"), performance-based RSUs and total shareholder return (“TSR”) awards. The Company measures and recognizes compensation expense for all stock options, service and performance-based restricted stock units granted to its employees and directors based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes valuation model to estimate the fair value of stock option awards. The determination of the grant date fair value of options using the Black-Scholes valuation model is affected by the Company’s estimated common stock fair value and requires management to make a number of assumptions including the expected life of the option, the volatility of the underlying stock, the risk-free interest rate and expected dividends. To estimate the fair value of the TSR awards, the Company uses the Monte Carlo valuation model to simulate the probabilities of achievement, which requires management to make a number of assumptions including 30-day average price, volatility of the underlying stock and the Company's peers, and the risk-free interest rate. The compensation cost of service-based stock options and restricted stock units is recognized net of any estimated forfeitures on a straight-line basis over the employee requisite service period. Compensation cost for performance-based RSUs is expensed over the respective vesting periods when the achievement of performance criteria is probable. Compensation cost for the TSR awards is recognized over the requisite service period, regardless of when, if ever, the market condition is satisfied. The Company believes that the fair value of stock options granted to non-employees is more reliably measured than the fair value of the services received. Net Loss per Share Potential common shares that would have the effect of increasing diluted earnings per share are considered to be anti-dilutive and as such, these shares are not included in the calculation of diluted earnings per share. The Company reported a net loss for each interim period presented. Therefore, dilutive common shares are not assumed to have been issued since their effect is anti-dilutive. Diluted weighted average shares excluded potential common shares related to stock options, restricted stock units (including service-based RSUs, performance-based RSUs and TSR awards) and shares to be purchased under the employee stock purchase plan totaling 14.2 million and 11.4 million for the three months ended June 30, 2022 and 2021 , and totaling 13.3 million and 9.4 million for the six months ended June 30, 2022 and 2021 , respectively, as they were anti-dilutive. Risks and Uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, the results of clinical trials and the achievement of milestones, research developments, actions by regulatory authorities, market acceptance of the Company’s product candidates, competition from other products and larger companies, intellectual property protection for the Company's proprietary technology, strategic relationships, and dependence on key individuals, suppliers, clinical organization, and other third parties. Recently Issued Accounting Guidance Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ ASU 2020-04” ) , which provides companies with optional financial reporting alternatives to reduce the cost and complexity associated with the accounting for contracts and hedging relationships affected by reference rate reform. This guidance is effective as of March 12, 2020 through December 31, 2022. Subsequently in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848): Scope , which clarifies ASU 2020-04 and provides certain optional expedients that allow derivative instruments impacted by changes in the interest rate used for margining, discounting or contract price alignment to qualify for certain optional relief. ASU 2021-01 is effective in the same timeframe as ASU2020-04. The relief offered by this guidance, if adopted, is available to companies for the period March 12, 2020 through December 31, 2022. The Company has certain lease arrangements that are linked to the London Inter-Bank Offered Rate ("LIBOR"). The Company is in the process of evaluating options for transitioning away from LIBOR and expects to complete this analysis by the time LIBOR is phased out. The Company did not elect to apply any of the expedients or exceptions as of and for the three and six months ended June 30, 2022 and is currently evaluating the impact on its condensed consolidated financial statements and related disclosures upon adoption of this guidance.
Stock-Based Compensation	Stock-Based Compensation The Company maintains equity incentive plans under which incentive and nonqualified stock options are granted to employees, which are comprised of stock options, service-based restricted stock units ("RSUs"), performance-based RSUs and total shareholder return (“TSR”) awards. The Company measures and recognizes compensation expense for all stock options, service and performance-based restricted stock units granted to its employees and directors based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes valuation model to estimate the fair value of stock option awards. The determination of the grant date fair value of options using the Black-Scholes valuation model is affected by the Company’s estimated common stock fair value and requires management to make a number of assumptions including the expected life of the option, the volatility of the underlying stock, the risk-free interest rate and expected dividends. To estimate the fair value of the TSR awards, the Company uses the Monte Carlo valuation model to simulate the probabilities of achievement, which requires management to make a number of assumptions including 30-day average price, volatility of the underlying stock and the Company's peers, and the risk-free interest rate. The compensation cost of service-based stock options and restricted stock units is recognized net of any estimated forfeitures on a straight-line basis over the employee requisite service period. Compensation cost for performance-based RSUs is expensed over the respective vesting periods when the achievement of performance criteria is probable. Compensation cost for the TSR awards is recognized over the requisite service period, regardless of when, if ever, the market condition is satisfied. The Company believes that the fair value of stock options granted to non-employees is more reliably measured than the fair value of the services received.
Net Loss per Share	Net Loss per Share Potential common shares that would have the effect of increasing diluted earnings per share are considered to be anti-dilutive and as such, these shares are not included in the calculation of diluted earnings per share. The Company reported a net loss for each interim period presented. Therefore, dilutive common shares are not assumed to have been issued since their effect is anti-dilutive. Diluted weighted average shares excluded potential common shares related to stock options, restricted stock units (including service-based RSUs, performance-based RSUs and TSR awards) and shares to be purchased under the employee stock purchase plan totaling 14.2 million and 11.4 million for the three months ended June 30, 2022 and 2021 , and totaling 13.3 million and 9.4 million for the six months ended June 30, 2022 and 2021 , respectively, as they were anti-dilutive.
Risks and Uncertainties	Risks and Uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, the results of clinical trials and the achievement of milestones, research developments, actions by regulatory authorities, market acceptance of the Company’s product candidates, competition from other products and larger companies, intellectual property protection for the Company's proprietary technology, strategic relationships, and dependence on key individuals, suppliers, clinical organization, and other third parties.
Recently Issued Accounting Guidance Not Yet Adopted	Recently Issued Accounting Guidance Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ ASU 2020-04” ) , which provides companies with optional financial reporting alternatives to reduce the cost and complexity associated with the accounting for contracts and hedging relationships affected by reference rate reform. This guidance is effective as of March 12, 2020 through December 31, 2022. Subsequently in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848): Scope , which clarifies ASU 2020-04 and provides certain optional expedients that allow derivative instruments impacted by changes in the interest rate used for margining, discounting or contract price alignment to qualify for certain optional relief. ASU 2021-01 is effective in the same timeframe as ASU2020-04. The relief offered by this guidance, if adopted, is available to companies for the period March 12, 2020 through December 31, 2022. The Company has certain lease arrangements that are linked to the London Inter-Bank Offered Rate ("LIBOR"). The Company is in the process of evaluating options for transitioning away from LIBOR and expects to complete this analysis by the time LIBOR is phased out. The Company did not elect to apply any of the expedients or exceptions as of and for the three and six months ended June 30, 2022 and is currently evaluating the impact on its condensed consolidated financial statements and related disclosures upon adoption of this guidance.
Collaboration Agreements, License Agreement and Revenues	Astellas Agreements Japan Agreement In June 2005, the Company entered into a collaboration agreement with Astellas for the development and commercialization (but not manufacture) of roxadustat for the treatment of anemia in Japan (“Japan Agreement”). Under this agreement, Astellas agreed to pay license fees, other upfront consideration and various milestone payments, totaling $ 172.6 million . The Japan Agreement also provides for tiered payments based on net sales of product (as defined) in the low 20% range of the list price published by Japan’s Ministry of Health, Labour and Welfare, adjusted for certain elements, after commercial launch. The aggregate amount of consideration received through June 30, 2022 totaled $ 105.1 million , excluding drug product revenue that is discussed separately below.
Product Revenue, Net	Product Revenue, Net Product revenue, net from the sales of roxadustat commercial product in China was as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Direct Sales: Gross revenue $ 3,533 $ 2,230 $ 6,362 $ 7,659 Discounts and rebates ( 13 ) ( 618 ) ( 187 ) ( 1,181 ) Sales returns ( 1 ) ( 1 ) 3 88 Direct sales revenue, net 3,519 1,611 6,178 6,566 Sales to Falikang: Gross transaction price 28,281 26,714 51,007 51,115 Profit share ( 10,065 ) ( 9,573 ) ( 18,914 ) ( 19,636 ) Net transaction price 18,216 17,141 32,093 31,479 Decrease (increase) in deferred revenue 1,521 ( 5,381 ) 3,866 ( 9,312 ) Sales to Falikang revenue, net 19,737 11,760 35,959 22,167 Total product revenue, net $ 23,256 $ 13,371 $ 42,137 $ 28,733 Direct Sales Product revenue from direct roxadustat product sales to distributors in China is recognized in an amount that reflects the consideration that the Company expects to be entitled to in exchange for those products, net of various sales rebates and discounts. The total discounts and rebates were immaterial for the periods presented. Due to the Company’s legal right to offset, at each balance sheet date, the rebates and discounts are presented as reductions to gross accounts receivable from the distributor, or as a current liability to the distributor to the extent that the total amount exceeds the gross accounts receivable or when the Company expects to settle the discount in cash. The Company’s legal right to offset is calculated at the individual distributor level. The following table includes a roll-forward of the contract liabilities (in thousands): Balance at Additions Deduction Currency Balance at Product revenue - Direct sales - contract liabilities $ ( 3,176 ) $ ( 286 ) $ 1,903 $ 157 $ ( 1,402 ) The above contract liabilities were included in accrued and other current liabilities in the condensed consolidated balance sheet. The rebates and discounts reflected as reductions to gross accounts receivable for direct sales wer e $ 0.7 million and $ 1.1 million a s of June 30, 2022 and December 31, 2021, respectively. Sales to Falikang – China Performance Obligation Since Falikang became fully operational in January 2021, substantially all direct roxadustat product sales to distributors in China are made by Falikang. FibroGen Beijing manufactures and supplies commercial product to Falikang. The net transfer price for FibroGen Beijing’s product sales to Falikang is based on a gross transfer price, which is adjusted to account for the 50/50 profit share for the period. The roxadustat sales to Falikang marked the beginning of the Company’s China performance obligation under the Company’s agreements with AstraZeneca . Product revenue is based on the transaction price of the China performance obligation. Revenue is recognized when control of the product is transferred to Falikang, in an amount that reflects the allocation of the transaction price to the performance obligation satisfied during the reporting period. Any net transaction price in excess of the revenue recognized is added to the deferred balance to date, and will be recognized over future periods as the performance obligation is satisfied. Following updates to its estimates, the Company recognized $ 1.5 million and $ 3.9 million from the previously deferred revenue of the China performance obligation during the three and six months ended June 30, 2022, respectively. The following table includes a roll-forward of the related deferred revenue that is considered as a contract liability (in thousands): Balance at Additions Recognized as Revenue Currency Balance at Product revenue - AstraZeneca China $ ( 171,516 ) $ ( 36,184 ) $ 35,959 $ 1,227 $ ( 170,514 ) Deferred revenue includes amounts allocated to the China performance obligation under the AstraZeneca arrangement as revenue recognition associated with this unit of accounting is tied to the commercial launch of the products within China and to when the control of the manufactured commercial products is transferred to AstraZeneca. As of June 30, 2022 , approximately $ 14.9 million of the above deferred revenue related to the China unit of accounting was included in short-term deferred revenue, which represents the amount of deferred revenue associated with the China unit of accounting that is expected to be recognized within the next 12 months, associated with the commercial sales in China. Due to the Company’s legal right to offset, at each balance sheet date, the rebates and discounts, mainly related to profit sharing, are presented as reductions to gross accounts receivable from Falikang, which was $ 6.5 million and $ 13.4 million as of June 30, 2022 and December 31, 2021 , respectively.
Drug Product Revenue	Drug Product Revenue Drug product revenue from commercial-grade active pharmaceutical ingredient (“API”) or bulk drug product sales to Astellas and AstraZeneca was as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Astellas - Japan Agreement $ 17 $ ( 1,974 ) $ 7,611 $ 2,056 Astellas - Europe Agreement 1,076 — 1,076 — AstraZeneca - U.S. Agreement — ( 6,674 ) — ( 2,224 ) Drug product revenue $ 1,093 $ ( 8,648 ) $ 8,687 $ ( 168 ) During the first quarter of 2022, the Company fulfilled a shipment obligation under the terms of Japan Amendment with Astellas, and recognized related drug product revenue of $ 9.8 million in the same period. In addition, the Company updated its estimate of variable consideration related to the API shipments fulfilled under the terms of Japan Amendment with Astellas, and accordingly recorded adjustments to the drug product revenue of $( 2.2 ) million, $( 2.0 ) million and $ 4.0 million for the first quarter of 2022, the second quarter of 2021 and the first quarter of 2021, respectively. Specifically, the change in estimated variable consideration was based on the API held by Astellas at period end, adjusted to reflect the changes in the estimated bulk product strength mix intended to be manufactured by Astellas, estimated cost to convert the API to bulk product tablets, and estimated yield from the manufacture of bulk product tablets, among others. During the second quarter of 2022, the Company transferred bulk drug product for commercial purposes under the terms of the Europe Agreement and the EU Supply Agreement with Astellas, and recognized the related fully burdened manufacturing costs of $ 1.0 million as drug product revenue, and recorded $ 23.2 million as deferred revenue due to a high degree of uncertainty associated with the final consideration. In addition, the Company recognized royalty revenue of $ 0.1 million as drug product revenue from the deferred revenue under the Europe Agreement during the second quar ter of 2022. The remainder of the deferred revenue will be recognized as and when uncertainty is resolved, based on the performance of roxadustat product sales in the territory. During the first quarter of 2022, the Company billed and received $ 49.2 million from Astellas related to the annual transfer price true up for bulk drug product transferred for commercial purposes. This amount was recorded in deferred revenue and netted against an unbilled contract asset as of December 31, 2021. During the first and second quarter of 2022, the Company updated its estimate of variable consideration related to the bulk drug product transferred in prior years. Specifically, the change in estimated variable consideration was based on the bulk drug product held by Astellas at the period end, adjusted to reflect the changes in the estimated transfer price, forecast information, shelf-life estimates and other items. As a result, the Company reclassified $ 43.3 million from deferred revenue to accrued liabilities as of June 30, 2022, representing its best estimate that this amount will be paid in the first quarter of 2023. During the first quarter of 2022, the Company evaluated the current developments in the U.S. market, and updated its estimates of variable consideration associated with bulk drug product shipments to AstraZeneca in prior years as commercial supply. As a result, the Company reclassified $ 11.2 million from the related deferred revenue to accrued liabilities as of June 30, 2022. The following table includes a roll-forward of the above-mentioned deferred revenues that are considered as contract liabilities related to drug product (in thousands): Balance at Additions Recognized as Revenue Reclassified to Accrued Liability / Accounts Payable Balance at Astellas - Japan Agreement $ ( 1,974 ) $ ( 2,226 ) $ — $ 4,200 $ — Astellas - Europe Agreement ( 25,891 ) ( 72,409 ) 90 43,273 ( 54,937 ) AstraZeneca - U.S. Agreement ( 11,171 ) — — 11,171 — Drug product revenue - deferred revenue $ ( 39,036 ) $ ( 74,635 ) $ 90 $ 58,644 $ ( 54,937 )

Collaboration Agreements, Lic_2

Collaboration Agreements, License Agreement and Revenues (Tables)	6 Months Ended
	Jun. 30, 2022
Transaction Price Related to Consideration Received and Accounts Receivable Allocated to Performance Obligations along with Associated Deferred Revenue and Product Revenue Net	Product revenue, net from the sales of roxadustat commercial product in China was as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Direct Sales: Gross revenue $ 3,533 $ 2,230 $ 6,362 $ 7,659 Discounts and rebates ( 13 ) ( 618 ) ( 187 ) ( 1,181 ) Sales returns ( 1 ) ( 1 ) 3 88 Direct sales revenue, net 3,519 1,611 6,178 6,566 Sales to Falikang: Gross transaction price 28,281 26,714 51,007 51,115 Profit share ( 10,065 ) ( 9,573 ) ( 18,914 ) ( 19,636 ) Net transaction price 18,216 17,141 32,093 31,479 Decrease (increase) in deferred revenue 1,521 ( 5,381 ) 3,866 ( 9,312 ) Sales to Falikang revenue, net 19,737 11,760 35,959 22,167 Total product revenue, net $ 23,256 $ 13,371 $ 42,137 $ 28,733
Roll-forward of Related Contract Liabilities	The following table includes a roll-forward of the contract liabilities (in thousands): Balance at Additions Deduction Currency Balance at Product revenue - Direct sales - contract liabilities $ ( 3,176 ) $ ( 286 ) $ 1,903 $ 157 $ ( 1,402 )
Schedule of Drug Product Revenue	Drug product revenue from commercial-grade active pharmaceutical ingredient (“API”) or bulk drug product sales to Astellas and AstraZeneca was as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Astellas - Japan Agreement $ 17 $ ( 1,974 ) $ 7,611 $ 2,056 Astellas - Europe Agreement 1,076 — 1,076 — AstraZeneca - U.S. Agreement — ( 6,674 ) — ( 2,224 ) Drug product revenue $ 1,093 $ ( 8,648 ) $ 8,687 $ ( 168 )
Summary of Amounts Recognized as Revenue	Amounts recognized as revenue under the Eluminex were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 Eluminex Other revenue - contract manufacturing $ 280 $ — $ 1,042 $ —
Drug Product Revenue [Member]
Roll-forward of Related Contract Liabilities	The following table includes a roll-forward of the above-mentioned deferred revenues that are considered as contract liabilities related to drug product (in thousands): Balance at Additions Recognized as Revenue Reclassified to Accrued Liability / Accounts Payable Balance at Astellas - Japan Agreement $ ( 1,974 ) $ ( 2,226 ) $ — $ 4,200 $ — Astellas - Europe Agreement ( 25,891 ) ( 72,409 ) 90 43,273 ( 54,937 ) AstraZeneca - U.S. Agreement ( 11,171 ) — — 11,171 — Drug product revenue - deferred revenue $ ( 39,036 ) $ ( 74,635 ) $ 90 $ 58,644 $ ( 54,937 )
AstraZeneca Agreements [Member]
Roll-forward of Related Contract Liabilities	The following table includes a roll-forward of the related deferred revenue that is considered as a contract liability (in thousands): Balance at Additions Recognized as Revenue Currency Balance at Product revenue - AstraZeneca China $ ( 171,516 ) $ ( 36,184 ) $ 35,959 $ 1,227 $ ( 170,514 )
Japan [Member]
Summary of License Revenue and Development Revenue Recognized under Agreement	Amounts recognized as license revenue and development revenue under the Japan Agreement with Astellas were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 Japan License revenue $ — $ — $ — $ — Development revenue $ 79 $ 99 $ 111 $ 179
Transaction Price Related to Consideration Received and Accounts Receivable Allocated to Performance Obligations along with Associated Deferred Revenue and Product Revenue Net	The transaction price related to consideration received and accounts receivable has been allocated to each of the following performance obligations under the Japan Agreement with Astellas, along with any associated deferred revenue as follows (in thousands): Japan Agreement Cumulative Deferred Total License $ 100,347 $ — $ 100,347 Development revenue 16,709 — 16,709 Total license and development revenue $ 117,056 $ — $ 117,056
Europe [Member]
Summary of License Revenue and Development Revenue Recognized under Agreement	Amounts recognized as license revenue and development revenue under the Europe Agreement with Astellas were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 Europe License revenue $ — $ — $ 22,590 $ — Development revenue $ 1,746 $ 2,546 $ 6,894 $ 6,077
Transaction Price Related to Consideration Received and Accounts Receivable Allocated to Performance Obligations along with Associated Deferred Revenue and Product Revenue Net	The transaction price related to consideration received and accounts receivable has been allocated to each of the following performance obligations under the Europe Agreement with Astellas, along with any associated deferred revenue as follows (in thousands): Europe Agreement Cumulative Deferred Total License $ 618,975 $ — $ 618,975 Development revenue 277,536 — 277,536 Total license and development revenue $ 896,511 $ — $ 896,511
U.S./RoW and China [Member]
Summary of License Revenue and Development Revenue Recognized under Agreement	Amounts recognized as revenue under the U.S./RoW Agreement and China Agreement with AstraZeneca were as follows for the three and six months ended June 30, 2022 and 2021 (in thousands): Three Months Ended June 30, Six Months Ended June 30, Agreement Performance Obligation 2022 2021 2022 2021 U.S. / RoW License revenue $ — $ — $ — $ — Development revenue 3,352 16,993 9,171 27,969
Transaction Price Related to Consideration Received and Accounts Receivable Allocated to Performance Obligations along with Associated Deferred Revenue and Product Revenue Net	The transaction price relat ed to consideration received and accounts receivable has been allocated to each of the following performance obligations under the U.S./RoW Agreement and China Agreement with AstraZeneca, along with any associated deferred revenue as follows (in thousands): U.S. / RoW and China Agreements Cumulative Deferred Total License $ 341,844 $ — $ 341,844 Co-development, information sharing & 612,290 — 612,290 China performance obligation * 71,527 170,514 242,041 Total license and development revenue $ 1,025,661 $ 170,514 ** $ 1,196,175 * China performance obligation revenue is recognized as product revenue, as described under Product Revenue, Net section below. ** Contract assets and liabilities related to rights and obligations in the same contract are recorded net on the consolidated balance sheets. As of June 30, 2022, deferred revenue included $ 157.3 million related to the U.S./RoW Agreement and China Agreement, which represents the net of $ 170.5 million of deferred revenue presented above and a $ 13.2 million unbilled co-development revenue under the China Amendment with AstraZeneca.

Variable Interest Entity (Table

Variable Interest Entity (Tables)	6 Months Ended
	Jun. 30, 2022
Acquisition And Variable Interest Entity [Abstract]
Summary of Equity Method Investment	The Company’s equity method investment in Falikang was as follows (in thousands): Entity Ownership Percentage Balance at Share of Net Income Currency Balance at Falikang 51.1 % $ 3,825 $ 885 $ ( 216 ) $ 4,494

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Values of Financial Assets Measured on Recurring Basis	The fair values of the Company’s financial assets that are measured on a recurring basis are as follows (in thousands): June 30, 2022 Level 1 Level 2 Level 3 Total Money market funds $ 34,123 $ — $ — $ 34,123 Corporate bonds — 125,491 — 125,491 Commercial paper — 55,307 — 55,307 U.S. government bonds 105,383 10,972 — 116,355 Agency bonds — 14,930 — 14,930 Asset-backed securities — 4,741 — 4,741 Foreign government bonds — 4,954 — 4,954 Total $ 139,506 $ 216,395 $ — $ 355,901 December 31, 2021 Level 1 Level 2 Level 3 Total Money market funds $ 58,801 $ — $ — $ 58,801 Corporate bonds — 182,646 — 182,646 Commercial paper — 69,079 — 69,079 U.S. government bonds 91,522 — — 91,522 Agency bonds — 23,275 — 23,275 Asset-backed securities — 27,087 — 27,087 Foreign government bonds — 9,154 — 9,154 Total $ 150,323 $ 311,241 $ — $ 461,564

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Cash and Cash Equivalents	Cash and cash equivalents consisted of the following (in thousands): June 30, 2022 December 31, 2021 Cash $ 128,152 $ 111,422 Commercial paper 5,483 1,000 Money market funds 34,123 58,801 Total cash and cash equivalents $ 167,758 $ 171,223
Summary of Amortized Cost, Gross Unrealized Holding Gains or Losses, and Fair Value of Investments	The Company’s investments consist of available-for-sale debt investments and marketable equity investments. The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s investments by major investments type are summarized in the tables below (in thousands): June 30, 2022 Amortized Cost Gross Unrealized Gross Unrealized Fair Value Corporate bonds $ 127,387 $ — $ ( 1,896 ) $ 125,491 Commercial paper 49,824 — — 49,824 U.S. government bonds 118,142 — ( 1,787 ) 116,355 Agency bonds 15,235 — ( 305 ) 14,930 Asset-backed securities 4,751 — ( 10 ) 4,741 Foreign government bonds 5,032 — ( 78 ) 4,954 Total investments $ 320,371 $ — $ ( 4,076 ) $ 316,295 December 31, 2021 Amortized Cost Gross Unrealized Gross Unrealized Fair Value Corporate bonds $ 183,136 $ 2 $ ( 492 ) $ 182,646 Commercial paper 68,079 — — 68,079 U.S. government bonds 91,840 — ( 318 ) 91,522 Agency bonds 23,339 — ( 64 ) 23,275 Asset-backed securities 27,105 — ( 18 ) 27,087 Foreign government bonds 9,165 — ( 11 ) 9,154 Total investments $ 402,664 $ 2 $ ( 903 ) $ 401,763
Schedule of Inventory	Inventories consisted of the following (in thousands): June 30, 2022 December 31, 2021 Raw materials $ 1,220 $ 1,363 Work-in-progress 34,488 21,499 Finished goods 5,191 8,153 Total inventories $ 40,899 $ 31,015
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): June 30, 2022 December 31, 2021 Preclinical and clinical trial accruals $ 66,553 $ 56,283 API and bulk drug product price true-up 54,443 — Acquired in-process research and development asset — 35,000 Payroll and related accruals 13,480 20,909 Accrued co-promotion expenses - current 32,352 25,746 Contract liabilities to pharmaceutical distributors 1,402 3,176 Roxadustat profit share to AstraZeneca 7,497 7,895 Property taxes and other taxes 5,449 12,610 Professional services 4,929 6,074 Other 6,994 4,906 Total accrued and other current liabilities $ 193,099 $ 172,599

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Detail) shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022 shares	Jun. 30, 2021 shares	Jun. 30, 2022 Segment shares	Jun. 30, 2021 shares
Accounting Policy [Line Items]
Number of reportable segment | Segment			1
Anti-dilutive shares outstanding | shares	14.2	11.4	13.3	9.4

Collaboration Agreements, Lic_3

Collaboration Agreements, License Agreement and Revenues - Astellas Agreements - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended			6 Months Ended
	Apr. 30, 2006	Jun. 30, 2005	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue			$ 29,806,000		$ 24,364,000	$ 90,633,000	$ 62,793,000
Deferred Revenue			6,897,000			6,897,000		$ 15,857,000
Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue			1,093,000		8,648,000	8,687,000	(168,000)
Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction price, variable consideration from estimated future co-development billing						0
Japan [Member] | Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue				$ 9,800,000
Europe [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction price, variable consideration from estimated future co-development billing						$ 7,600,000
Astellas Agreement [Member] | Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront, non-contingent and time-based payments received		$ 172,600,000
Additional consideration based on net sales description						the low 20% range of the list price
Aggregate consideration received excluding drug product revenue			105,100,000			$ 105,100,000
Revenue resulting from changes to estimated variable consideration			0
Astellas Agreement [Member] | Japan [Member] | Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue					(2,000,000)	$ 7,600,000	2,100,000
Astellas Agreement [Member] | Europe [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront, non-contingent and time-based payments received	$ 745,000,000
Additional consideration based on net sales description						low 20% range
Aggregate consideration received excluding drug product revenue			685,000,000			$ 685,000,000
Total revenue			1,100,000		$ 0	$ 1,100,000	$ 0
Percentage of joint development costs committed to fund	50%
Transaction price and allocated to performance obligations				$ 25,000,000
Changes in revenue from changes to estimated variable consideration			$ 0

Collaboration Agreements, Lic_4

Collaboration Agreements, License Agreement and Revenues - AstraZeneca Agreements - Additional Information 1 (Detail) - USD ($)		3 Months Ended		6 Months Ended
	Jul. 30, 2013	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		$ 29,806,000	$ 24,364,000	$ 90,633,000	$ 62,793,000
Deferred Revenue		6,897,000		6,897,000		$ 15,857,000
Drug product revenue recognized		29,806,000	24,364,000	90,633,000	62,793,000
Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		23,256,000	13,371,000	42,137,000	28,733,000
Drug product revenue recognized		23,256,000	13,371,000	42,137,000	28,733,000
Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		1,093,000	8,648,000	8,687,000	(168,000)
Drug product revenue recognized		1,093,000	8,648,000	$ 8,687,000	(168,000)
AstraZeneca Agreements [Member] | U.S./RoW [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront, non-contingent, non-refundable and time-based payments	$ 1,200,000,000
Additional consideration based on net sales description				low 20% range
Aggregate consideration received excluding drug product revenue		439,000,000		$ 439,000,000
AstraZeneca Agreements [Member] | U.S./RoW [Member] | Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		0	(6,700,000)	0	(2,200,000)
Drug product revenue recognized		0	(6,700,000)	0	(2,200,000)
AstraZeneca Agreements [Member] | China [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront, non-contingent, non-refundable and time-based payments	$ 376,700,000
Aggregate considerations received				77,200,000
AstraZeneca Agreements [Member] | China [Member] | Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		19,700,000	11,800,000	36,000,000	22,200,000
Drug product revenue recognized		19,700,000	11,800,000	36,000,000	22,200,000
Direct Sales [Member] | Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		3,519,000	1,611,000	6,178,000	6,566,000
Drug product revenue recognized		3,519,000	1,611,000	6,178,000	6,566,000
Direct Sales [Member] | China [Member] | Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue		3,500,000	1,600,000	6,200,000	6,600,000
Drug product revenue recognized		$ 3,500,000	$ 1,600,000	$ 6,200,000	$ 6,600,000

Collaboration Agreements, Lic_5

Collaboration Agreements, License Agreement and Revenues - Summary of License Revenue and Development Revenue Recognized under Agreement (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	$ 29,806,000	$ 24,364,000	$ 90,633,000	$ 62,793,000
License Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	0	0	22,590,000	0
Development Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	5,457,000	19,641,000	17,219,000	34,228,000
Astellas Agreement [Member] | Europe [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	1,100,000	0	1,100,000	0
Astellas Agreement [Member] | License Revenue [Member] | Japan [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	0	0	0	0
Astellas Agreement [Member] | License Revenue [Member] | Europe [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	0	0	22,590,000	0
Astellas Agreement [Member] | Development Revenue [Member] | Japan [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	79,000	99,000	111,000	179,000
Astellas Agreement [Member] | Development Revenue [Member] | Europe [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	1,746,000	2,546,000	6,894,000	6,077,000
AstraZeneca Agreements [Member] | License Revenue [Member] | U.S./RoW and China [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	0	0	0	0
AstraZeneca Agreements [Member] | Development Revenue [Member] | U.S./RoW and China [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	$ 3,352,000	$ 16,993,000	$ 9,171,000	$ 27,969,000

Collaboration Agreements, Lic_6

Collaboration Agreements, License Agreement and Revenues - Transaction Price Related to Consideration Received and Accounts Receivable Allocated to Performance Obligations along with Associated Deferred Revenue (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Astellas Agreement [Member] | Japan [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	$ 117,056
Deferred Revenue	0
Total Consideration	117,056
Astellas Agreement [Member] | Japan [Member] | Development Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	16,709
Deferred Revenue	0
Total Consideration	16,709
Astellas Agreement [Member] | Japan [Member] | License Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	100,347
Deferred Revenue	0
Total Consideration	100,347
Astellas Agreement [Member] | Europe [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	896,511
Deferred Revenue	0
Total Consideration	896,511
Astellas Agreement [Member] | Europe [Member] | Development Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	277,536
Deferred Revenue	0
Total Consideration	277,536
Astellas Agreement [Member] | Europe [Member] | License Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	618,975
Deferred Revenue	0
Total Consideration	618,975
AstraZeneca Agreements [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred Revenue	170,514	$ 171,516
AstraZeneca Agreements [Member] | U.S./RoW and China [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	1,025,661
Deferred Revenue	170,514
Total Consideration	1,196,175
AstraZeneca Agreements [Member] | U.S./RoW and China [Member] | License Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	341,844
Deferred Revenue	0
Total Consideration	341,844
AstraZeneca Agreements [Member] | U.S./RoW and China [Member] | Co-development, information sharing & committee services [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	612,290
Deferred Revenue	0
Total Consideration	612,290
AstraZeneca Agreements [Member] | U.S./RoW and China [Member] | China performance obligation [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative Revenue	71,527
Deferred Revenue	170,514
Total Consideration	$ 242,041

Collaboration Agreements, Lic_7

Collaboration Agreements, License Agreement and Revenues - Summary of Revenue Recognized Under the Collaboration Agreements - Additional Information 4 (Detail) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022
Europe [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Remainder of transaction price, variable consideration from estimated future co-development billing		$ 7,600,000
Europe [Member] | Astellas Agreement [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Changes in revenue from changes to estimated variable consideration	$ 0
U.S./RoW and China [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Remainder of transaction price, variable consideration from estimated future co-development billing		18,000,000
Changes in revenue from changes to estimated variable consideration		$ 0

Collaboration Agreements, Lic_8

Collaboration Agreements, License Agreement and Revenues - Transaction Price Related to Consideration Received and Accounts Receivable Allocated to Performance Obligations Deferred Revenue (Parenthetical) (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred revenue, net of current ($49,2733 and $25,891 to a related party)	$ 205,351	$ 186,801
AstraZeneca Agreements [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred Revenue	170,514	$ 171,516
AstraZeneca Agreements [Member] | U.S./RoW [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred revenue, net of current ($49,2733 and $25,891 to a related party)	157,300
Deferred Revenue	170,500
Net unbilled co-development revenue	$ 13,200

Collaboration Agreements, Lic_9

Collaboration Agreements, License Agreement and Revenues - Summary of Product Revenue, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Line Items]
Total revenue	$ 29,806	$ 24,364	$ 90,633	$ 62,793
Product Revenue, Net [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	23,256	13,371	42,137	28,733
Product Revenue, Net [Member] | Direct Sales [Member]
Disaggregation Of Revenue [Line Items]
Gross revenue	3,533	2,230	6,362	7,659
Total revenue	3,519	1,611	6,178	6,566
Product Revenue, Net [Member] | Direct Sales [Member] | Discounts and Rebates [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	(13)	(618)	(187)	(1,181)
Product Revenue, Net [Member] | Direct Sales [Member] | Sales Returns [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	1	1	3	88
Product Revenue, Net [Member] | Sales To Falikang [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	19,737	11,760	35,959	22,167
Gross transfer price	28,281	26,714	51,007	51,115
Product Revenue, Net [Member] | Sales To Falikang [Member] | Profit Share [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	(10,065)	(9,573)	(18,914)	(19,636)
Product Revenue, Net [Member] | Sales To Falikang [Member] | Net Transfer Price [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	18,216	17,141	32,093	31,479
Product Revenue, Net [Member] | Sales To Falikang [Member] | Increase in Deferred Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ (1,521)	$ (5,381)	$ 3,866	$ (9,312)

Collaboration Agreements, Li_10

Collaboration Agreements, License Agreement and Revenues - Product Revenue, Net - Additional Information 1 (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue	$ 29,806	$ 24,364	$ 90,633	$ 62,793
Rebates and Discounts [Member] | Gross Accounts Receivable [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue			700		$ 1,100
Constrained for Future Recognition [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenue	$ 1,500		$ 3,900

Collaboration Agreements, Li_11

Collaboration Agreements, License Agreement and Revenues - Roll-forward of Related Contract Liabilities (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)
AstraZeneca Agreements [Member]
Contract with Customer Liability [Line Items]
Balance at December 31, 2021	$ (171,516)
Additions	(36,184)
Currency Translation and Other	1,227
Recognized as Revenue	35,959
Balance at June 30, 2022	(170,514)
Product Revenue, Net [Member] | Direct Sales [Member] | Contract Liabilities [Member]
Contract with Customer Liability [Line Items]
Balance at December 31, 2021	(3,176)
Additions	(286)
Deduction	1,903
Currency Translation and Other	157
Balance at June 30, 2022	(1,402)
Drug Product Revenue [Member]
Contract with Customer Liability [Line Items]
Balance at December 31, 2021	(39,036)
Additions	(74,635)
Reclassified to Accrued Liability	58,644
Recognized as Revenue	90
Balance at June 30, 2022	(54,937)
Drug Product Revenue [Member] | AstraZeneca Agreements [Member] | U.S. [Member]
Contract with Customer Liability [Line Items]
Balance at December 31, 2021	(11,171)
Additions	0
Reclassified to Accrued Liability	11,171
Recognized as Revenue	0
Balance at June 30, 2022	0
Drug Product Revenue [Member] | Astellas Agreement [Member] | Japan [Member]
Contract with Customer Liability [Line Items]
Balance at December 31, 2021	(1,974)
Additions	(2,226)
Reclassified to Accrued Liability	4,200
Recognized as Revenue	0
Balance at June 30, 2022	0
Drug Product Revenue [Member] | Astellas Agreement [Member] | Europe [Member]
Contract with Customer Liability [Line Items]
Balance at December 31, 2021	(25,891)
Additions	(72,409)
Reclassified to Accrued Liability	43,273
Recognized as Revenue	90
Balance at June 30, 2022	$ (54,937)

Collaboration Agreements, Li_12

Collaboration Agreements, License Agreement and Revenues - Deferred Revenue - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Product Revenue, Net [Member] | Beijing Falikang Pharmaceutical Co Ltd
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Reductions to gross accounts receivable	$ 6,500	$ 13,400
AstraZeneca Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue	170,514	$ 171,516
AstraZeneca Agreements [Member] | China [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 14,900

Collaboration Agreements, Li_13

Collaboration Agreements, License Agreement and Revenues - Drug Product Revenue - Summary of Drug Product Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	$ 29,806		$ 24,364	$ 90,633	$ 62,793
Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	1,093		8,648	8,687	(168)
Drug Product Revenue [Member] | Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized		$ 9,800
Drug Product Revenue [Member] | Astellas Agreement [Member] | Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	17		(1,974)	7,611	2,056
Drug Product Revenue [Member] | Astellas Agreement [Member] | Europe [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	1,076		0	1,076	0
Drug Product Revenue [Member] | AstraZeneca Agreements [Member] | U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	$ 0		$ (6,674)	$ 0	$ (2,224)

Collaboration Agreements, Li_14

Collaboration Agreements, License Agreement and Revenues - Drug Product Revenue - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred Revenue	$ 6,897				$ 6,897		$ 15,857
Drug product revenue recognized	29,806		$ 24,364		90,633	$ 62,793
Royalty Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred Revenue	100				100
Drug Product Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	1,093		8,648		8,687	(168)
Drug Product Revenue [Member] | Europe [Member] | Astellas Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	1,076		0		1,076	0
Drug Product Revenue [Member] | Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized		$ 9,800
Drug Product Revenue [Member] | Japan [Member] | Astellas Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	17		(1,974)		7,611	$ 2,056
Drug Product Revenue [Member] | API Shipment [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized		(2,200)	$ (2,000)	$ 4,000
Bulk Drug Product [Member] | Astellas Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized					43,300
Bulk Drug Product [Member] | Astra Zeneca Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized					11,200
Bulk Drug Product [Member] | E U Supply And Astellas Agreement [Member] | Europe [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred Revenue	23,200				$ 23,200
Billed Contracts Receivable		$ 49,200
Burdened manufacturing costs	$ 1,000

Collaboration Agreements, Li_15

Collaboration Agreements, License Agreement and Revenues - Eluminex Agreement - Additional Information 2 (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Jul. 31, 2021	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue		$ 29,806		$ 24,364	$ 90,633	$ 62,793
Eluminex [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Aggregate consideration received for milestone and upfront payments	$ 8,000
Future manufacturing clinical regulatory and commercial milestone payments	64,000
Commercial milestone	$ 36,000
Eluminex [Member] | Cornea Products [Member] | ASC 606 [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Percentage of product manufacturing costs until manufacturing technology fully transferred			110%

Collaboration Agreements, Li_16

Collaboration Agreements, License Agreement and Revenues - Summary of Amounts Recognized as Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	$ 29,806	$ 24,364	$ 90,633	$ 62,793
License Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	0	0	22,590	0
License Revenue [Member] | Eluminex [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue	$ 280	$ 0	$ 1,042	$ 0

Variable Interest Entity - Addi

Variable Interest Entity - Additional Information (Detail)	Jun. 30, 2022
Beijing Kangda Yongfu Pharmaceutical Co., LTD [Member] | Beijing Falikang Pharmaceutical Co Ltd | FibroGen Beijing [Member] | AstraZenecaAB [Member]
Acquisition And Variable Interest Entity [Line Items]
Percentage of outstanding shares acquired	51.10%

Variable Interest Entity - Summ

Variable Interest Entity - Summary of Equity Method Investment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Acquisition And Variable Interest Entity [Line Items]
Beginning balance			$ 3,825
Share of Net Income	$ 565	$ 562	885	$ 323
Ending balance	$ 4,494		$ 4,494
Beijing Falikang Pharmaceutical Co. Ltd [Member]
Acquisition And Variable Interest Entity [Line Items]
Ownership Percentage	51.10%		51.10%
Beginning balance			$ 3,825
Share of Net Income			885
Currency Translation			(216)
Ending balance	$ 4,494		$ 4,494

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values of Financial Assets Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	$ 316,295	$ 401,763
Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	125,491	182,646
Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	49,824	68,079
Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	4,741	27,087
Foreign government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	4,954	9,154
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	355,901	461,564
Fair Value, Measurements, Recurring [Member] | Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	34,123	58,801
Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	125,491	182,646
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	55,307	69,079
Fair Value, Measurements, Recurring [Member] | U.S. government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	116,355	91,522
Fair Value, Measurements, Recurring [Member] | Agency bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	14,930	23,275
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	4,741	27,087
Fair Value, Measurements, Recurring [Member] | Foreign government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	4,954	9,154
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	139,506	150,323
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	34,123	58,801
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	105,383	91,522
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Agency bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Foreign government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	216,395	311,241
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	125,491	182,646
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	55,307	69,079
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | U.S. government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	10,972	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Agency bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	14,930	23,275
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	4,741	27,087
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Foreign government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	4,954	9,154
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets fair value disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | U.S. government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Agency bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Foreign government bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)
Fair Value Disclosures [Abstract]
Transfers of assets from level 1 to 2	$ 0	$ 0
Transfers of assets from level 2 to 1	0	0
Transfers of assets into level 3	0	0
Transfers of assets out of level 3	$ 0	$ 0

Leases - Schedule of Lease Asse

Leases - Schedule of Lease Assets and Related Lease Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease right-of-use assets, net	$ 84,654	$ 91,112
Operating lease liabilities	10,984	10,944
Operating lease liabilities	$ 83,080	$ 88,776

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Lessee Lease Description [Line Items]
Operating lease right-of-use assets	$ 84,654	$ 91,112
Operating lease liability	$ 94,100

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Finance lease cost:
Amortization of right-of-use assets	$ 269	$ 4,393

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Financing cash flows from finance leases	$ 23	$ 5,326

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Detail) $ in Millions	Jun. 30, 2022 USD ($)
Operating Leases
Present value of lease liabilities	$ 94.1

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash	$ 128,152	$ 111,422
Commercial paper	5,483	1,000
Money market funds	34,123	58,801
Total cash and cash equivalents	$ 167,758	$ 171,223

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Jul. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 167,758,000		$ 167,758,000		$ 171,223,000
Other-than-temporary impairment loss	0	$ 0	0	$ 0
API and bulk drug product price true-up	54,443,000		54,443,000
Acquired In Process Research And Development Asset					35,000,000
Profit share liability	6,897,000		$ 6,897,000		15,857,000
Eluminex [Member]
Schedule of Available-for-sale Securities [Line Items]
Unbilled upfront payment						$ 8,000,000
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Contractual maturities of available-for-sale investments			2 years
Foreign subsidiaries [Member]
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 98,800,000		$ 98,800,000		$ 91,200,000

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Amortized Cost, Gross Unrealized Holding Gains or Losses, and Fair Value of Available-for-Sale Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 320,371	$ 402,664
Gross Unrealized Holding Gains	0	2
Gross Unrealized Holding Losses	(4,076)	(903)
Fair Value	316,295	401,763
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	127,387	183,136
Gross Unrealized Holding Gains	0	2
Gross Unrealized Holding Losses	(1,896)	(492)
Fair Value	125,491	182,646
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,824	68,079
Gross Unrealized Holding Gains	0
Gross Unrealized Holding Losses	0
Fair Value	49,824	68,079
U.S. government bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	118,142	91,840
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	(1,787)	(318)
Fair Value	116,355	91,522
Agency bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,235	23,339
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	(305)	(64)
Fair Value	14,930	23,275
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,751	27,105
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	(10)	(18)
Fair Value	4,741	27,087
Foreign government bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,032	9,165
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	(78)	(11)
Fair Value	$ 4,954	$ 9,154

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule of Investments [Abstract]
Raw materials	$ 1,220	$ 1,363
Work-in-progress	34,488	21,499
Finished goods	5,191	8,153
Total inventories	$ 40,899	$ 31,015

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accrued Liabilities, Current [Abstract]
Preclinical and clinical trial accruals	$ 66,553	$ 56,283
API and bulk drug product price true-up	54,443
Acquired in-process research and development asset		35,000
Payroll and related accruals	13,480	20,909
Accrued co-promotion expenses - current	1,402	3,176
Contract liabilities to pharmaceutical distributors	7,497	7,895
Roxadustat profit share to AstraZeneca	32,352	25,746
Property taxes and other taxes	5,449	12,610
Professional services	4,929	6,074
Other	6,994	4,906
Total accrued and other current liabilities	$ 193,099	$ 172,599

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Accounts Receivable, Related Parties, Current	$ 26,779		$ 26,779		$ 10,930
Accrued liabilities to related party	43,286		43,286		4
Investment income (loss)	(565)	$ (562)	(885)	$ (323)
Equity method investments	4,494		4,494		3,825
Astellas [Member]
Related Party Transaction [Line Items]
Drug product revenue from a related party	1,100	(2,000)	8,700	2,100
Astellas [Member] | Collaborative Arrangement [Member]
Related Party Transaction [Line Items]
Revenue related to collaboration agreements	1,800	2,600	29,600	6,300
Accounts Receivable, Related Parties, Current	26,100		26,100		10,900
Accrued liabilities to related party	43,300		43,300
Contract with Customer, Liability	54,900		54,900		27,900
Falikang [Member]
Related Party Transaction [Line Items]
Accounts Receivable, Related Parties, Current	700		700		0
Investment income (loss)	600	600	(900)	(300)
Equity method investments	4,500		$ 4,500		3,800
Percentage of outstanding shares owned			51.10%
Deferred revenue	0		$ 0		$ 1,200
Falikang [Member] | Collaborative Arrangement [Member]
Related Party Transaction [Line Items]
Revenue related to collaboration agreements	$ 19,700	$ 11,800	$ 36,000	$ 22,200

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	1 Months Ended		6 Months Ended
	May 31, 2021 PutativeClassAction	Apr. 30, 2021 PutativeClassAction	Jun. 30, 2022 USD ($)
Commitments And Contingencies [Line Items]
Operating lease liability			$ 94.1
Outstanding non-cancelable purchase obligations			57.7
Putative securities class action complaints filed | PutativeClassAction	2	3
Manufacture and Supply of Roxadustat [Member]
Commitments And Contingencies [Line Items]
Outstanding non-cancelable purchase obligations			9.2
Manufacture and Supply of Pamrevlumab [Member]
Commitments And Contingencies [Line Items]
Outstanding non-cancelable purchase obligations			33.2
Other Purchases [Member]
Commitments And Contingencies [Line Items]
Outstanding non-cancelable purchase obligations			15.3
Research and Pre-Clinical Stage Development Programs [Member]
Commitments And Contingencies [Line Items]
Maximum future milestone payments			$ 697.9

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021
Subsequent Event [Line Items]
Reduction of accrued and other current liabilities		$ 61,005	$ 27,745
Intellectual Property Rights [Member]
Subsequent Event [Line Items]
Reduction of accrued and other current liabilities	$ 8,200
Reduction of other assets	2,300
Reduction of other expenses	$ 6,000