Global Blood Therapeutics (GBT) 10-Q 3 Aug 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Jul. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Period End Date	Jun. 30, 2021
Entity Registrant Name	Global Blood Therapeutics, Inc.
Entity Filer Category	Large Accelerated Filer
Trading Symbol	GBT
Entity Emerging Growth Company	false
Entity Small Business	false
Document Transition Report	false
Entity Common Stock, Shares Outstanding		62,412,062
Document Quarterly Report	true
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity File Number	001-37539
Entity Tax Identification Number	27-4825712
Entity Shell Company	false
Entity Address, Address Line One	181 Oyster Point Boulevard
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
City Area Code	650
Local Phone Number	741-7700
Entity Address, Postal Zip Code	94080
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001629137
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 419,311	$ 494,766
Short-term marketable securities	18,085	66,126
Accounts receivable, net	19,544	17,500
Inventories	47,991	40,223
Prepaid expenses and other current assets	19,928	13,548
Total current assets	524,859	632,163
Property and equipment, net	36,775	37,882
Operating lease right-of-use assets	49,421	50,722
Restricted cash	2,395	2,436
Other assets, noncurrent	1,522	799
Total assets	614,972	724,002
Current liabilities:
Accounts payable	9,198	19,078
Accrued liabilities	38,904	31,133
Accrued compensation	19,330	23,985
Operating lease liabilities, current	5,243	4,836
Total current liabilities	72,675	79,032
Long-term debt	149,268	148,815
Operating lease liabilities, noncurrent	76,441	79,176
Other liabilities, noncurrent	822	822
Total liabilities	299,206	307,845
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized as of June 30, 2021 (unaudited) and December 31, 2020; no shares issued and outstanding
Common stock, $0.001 par value, 150,000,000 shares authorized as of June 30, 2021 (unaudited) and December 31, 2020, respectively; 62,379,118 and 61,898,090 shares issued and outstanding as of June 30, 2021 (unaudited) and December 31, 2020, respectively	62	62
Additional paid-in capital	1,446,393	1,402,262
Accumulated other comprehensive loss	302	302
Accumulated deficit	(1,130,991)	(986,469)
Total stockholders' equity	315,766	416,157
Total liabilities and stockholders' equity	$ 614,972	$ 724,002

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	62,379,118	61,898,090
Common stock, shares outstanding	62,379,118	61,898,090

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues [Abstract]
Product sales, net	$ 47,555	$ 31,501	$ 86,598	$ 45,619
Costs and operating expenses:
Cost of sales	748	377	1,332	512
Research and development	51,784	34,085	102,641	73,858
Selling, general and administrative	61,093	49,075	120,059	96,736
Total costs and operating expenses	113,625	83,537	224,032	171,106
Loss from operations	(66,070)	(52,036)	(137,434)	(125,487)
Other income (expense):
Interest income	164	1,514	493	4,370
Interest expense	(3,677)	(2,282)	(7,366)	(4,596)
Other expenses, net	(9)	(36)	(215)	(153)
Total other income, net	(3,522)	(804)	(7,088)	(379)
Net loss	(69,592)	(52,840)	(144,522)	(125,866)
Other comprehensive loss:
Net unrealized gain (loss) on marketable securities, net of tax	(78)	12	(259)	472
Cumulative translation adjustment	259	0	259	0
Comprehensive loss	$ (69,411)	$ (52,828)	$ (144,522)	$ (125,394)
Basic and diluted net loss per common share	$ (1.12)	$ (0.86)	$ (2.32)	$ (2.06)
Weighted-average number of shares used in computing basic and diluted net loss per common share	62,312,418	62,207,328	61,116,707	60,952,269

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2019	$ 578,694	$ 61	$ 1,316,795	$ 754	$ (738,916)
Beginning Balance, Shares at Dec. 31, 2019		60,644,380
Issuance of common stock upon exercise of stock options	967		967
Issuance of common stock upon exercise of stock options, Shares		33,937
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes	(2,099)		(2,099)
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares		160,594
Issuance of common stock pursuant to ESPP purchases	1,870		1,870
Issuance of common stock pursuant to ESPP purchases, Shares		47,460
Stock-based compensation	16,705		16,705
Net unrealized gain (loss) on marketable securities	461			461
Net loss	(73,026)				(73,026)
Ending Balance at Mar. 31, 2020	523,572	$ 61	1,334,238	1,215	(811,942)
Ending Balance, Shares at Mar. 31, 2020		60,886,371
Beginning Balance at Dec. 31, 2019	578,694	$ 61	1,316,795	754	(738,916)
Beginning Balance, Shares at Dec. 31, 2019		60,644,380
Cumulative translation adjustment	0
Net loss	(125,866)
Ending Balance at Jun. 30, 2020	495,816	$ 61	1,359,310	1,227	(864,782)
Ending Balance, Shares at Jun. 30, 2020		61,330,987
Beginning Balance at Mar. 31, 2020	523,572	$ 61	1,334,238	1,215	(811,942)
Beginning Balance, Shares at Mar. 31, 2020		60,886,371
Issuance of common stock upon exercise of stock options	8,018		8,018
Issuance of common stock upon exercise of stock options, Shares		334,454
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes	(74)		(74)
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares		110,162
Stock-based compensation	17,128		17,128
Net unrealized gain (loss) on marketable securities	12			12
Cumulative translation adjustment	0
Net loss	(52,840)				(52,840)
Ending Balance at Jun. 30, 2020	495,816	$ 61	1,359,310	1,227	(864,782)
Ending Balance, Shares at Jun. 30, 2020		61,330,987
Beginning Balance at Dec. 31, 2020	416,157	$ 62	1,402,262	302	(986,469)
Beginning Balance, Shares at Dec. 31, 2020		61,898,090
Issuance of common stock upon exercise of stock options	1,110		1,110
Issuance of common stock upon exercise of stock options, Shares		47,763
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes	(1,897)		(1,897)
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares		229,087
Issuance of common stock pursuant to ESPP purchases	2,558		2,558
Issuance of common stock pursuant to ESPP purchases, Shares		65,110
Stock-based compensation	20,378		20,378
Net unrealized gain (loss) on marketable securities	(181)			(181)
Net loss	(74,930)				(74,930)
Ending Balance at Mar. 31, 2021	363,195	$ 62	1,424,411	121	(1,061,399)
Ending Balance, Shares at Mar. 31, 2021		62,240,050
Beginning Balance at Dec. 31, 2020	$ 416,157	$ 62	1,402,262	302	(986,469)
Beginning Balance, Shares at Dec. 31, 2020		61,898,090
Issuance of common stock upon exercise of stock options, Shares	76,338
Cumulative translation adjustment	$ 259
Net loss	(144,522)
Ending Balance at Jun. 30, 2021	315,766	$ 62	1,446,393	302	(1,130,991)
Ending Balance, Shares at Jun. 30, 2021		62,379,118
Beginning Balance at Mar. 31, 2021	363,195	$ 62	1,424,411	121	(1,061,399)
Beginning Balance, Shares at Mar. 31, 2021		62,240,050
Issuance of common stock upon exercise of stock options	403		403
Issuance of common stock upon exercise of stock options, Shares		28,575
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes	(65)		(65)
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares		110,493
Stock-based compensation	21,644		21,644
Cumulative translation adjustment	259			259
Other comprehensive losses	(78)			(78)
Net loss	(69,592)				(69,592)
Ending Balance at Jun. 30, 2021	$ 315,766	$ 62	$ 1,446,393	$ 302	$ (1,130,991)
Ending Balance, Shares at Jun. 30, 2021		62,379,118

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (144,522)	$ (125,866)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,908	5,577
Amortization (accretion) of premium (discount) on marketable securities	112	(61)
Non-cash interest expense	476	824
Amortization of operating lease right-of-use assets	1,301	580
Stock-based compensation	41,184	32,938
Changes in operating assets and liabilities:
Accounts receivable	(2,044)	(9,834)
Inventories	(6,841)	(24,926)
Prepaid expenses and other assets	(7,121)	181
Accounts payable	(9,730)	(4,918)
Accrued liabilities	7,683	(1,326)
Accrued compensation	(4,655)	(1,114)
Other liabilities		156
Operating lease liabilities	(2,328)	1,686
Net cash used in operating activities	(123,577)	(126,103)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(1,920)	(3,918)
Purchase of marketable securities		(57,936)
Maturities of marketable securities	47,670	261,738
Net cash provided by investing activities	45,750	199,884
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock in settlement of employee stock purchase plan and exercise of stock options	4,083	11,000
Payments of debt issuance costs	(49)	(130)
Tax paid related to net share settlement of equity awards	(1,962)	(2,172)
Net cash provided by financing activities	2,072	8,698
Effect of exchange rate changes on cash and cash equivalents	259
Net (decrease) increase in cash, cash equivalents and restricted cash	(75,496)	82,479
Cash, cash equivalents and restricted cash at beginning of period	497,202	304,632
Cash, cash equivalents and restricted cash at end of period	421,706	387,111
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest	6,788	3,419
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Leasehold improvements paid for by landlord		10,709
Accrued purchase of property and equipment	(36)	3,773
Accrued issuance costs	(26)	(85)
RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH TO THE CONDENSED CONSOLIDATED BALANCE SHEETS
Cash and cash equivalents	419,311	384,716
Restricted cash	2,395	2,395
Total cash and cash equivalents and restricted cash	$ 421,706	$ 387,111

Organization

Organization	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Global Blood Therapeutics, Inc., or the Company, we, us, or our, was incorporated in Delaware in February 2011 and commenced operations in May 2012. We are a biopharmaceutical company dedicated to the discovery, development and delivery of life-changing treatments that provide hope to underserved patient communities. In late November 2019, we received U.S. Food and Drug Administration, or FDA, accelerated approval for our first medicine, Oxbryta ® Need for Additional Capital In the course of our development activities, we have sustained operating losses and we expect such losses to continue over the next several years. Our ultimate success depends on the outcome of our commercialization of Oxbryta and research and development activities. Since inception through June 30, 2021, we have incurred cumulative net losses of $1.13 billion. We expect to incur additional losses for the foreseeable future to commercialize Oxbryta and conduct product research and development, and expect to potentially raise additional capital to fully implement our business plan. If needed, we intend to raise such capital through borrowings, the issuance of additional equity, and potentially through strategic alliances with partner companies or other transactions. However, if such financing is not available at adequate levels, we will need to re-evaluate

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Preparation and Presentation of Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and, accordingly, the balance sheet as of December 31, 2020, has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as our annual consolidated financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair presentation of our financial information. The results of operations for the six months ended June 30, 2021, are not necessarily indicative of the results to be expected for the year ending December 31, 2021, or for any other interim period or for any other future year. The accompanying unaudited interim condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2020, included in our Annual Report on Form 10-K, Use of Estimates The preparation of the accompanying unaudited interim condensed consolidated financial statements in accordance with U.S. GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of variable consideration and costs and expenses during the reporting period. We base our estimates and assumptions on historical experience when available and on various factors that we believe to be reasonable under the circumstances. We evaluate our estimates and assumptions on an ongoing basis. Our actual results could differ from these estimates under different assumptions or conditions. Concentration of Risk Credit Risk We invest in a variety of financial instruments and, by our Board approved investment policy, limit the amount of credit exposure with any one issuer, industry or geographic area for investments other than instruments backed by the U.S. federal government. Major Customers We have entered into distribution agreements with certain limited specialty pharmacies and specialty distributors. For the six months ended June 30, 2021, our two largest customers represented approximately 85% of our product revenue and approximately 81% of our accounts receivable balance at June 30, 2021. Major Suppliers We do not currently have any of our own manufacturing facilities, and, therefore, depend on an outsourced manufacturing strategy for the production of Oxbryta for commercial use and for the production of our product candidates for clinical trials. We have contracts in place with one third-party manufacturer that is approved for the commercial production of Oxbryta and two third-party suppliers that are approved for Oxbryta’s active pharmaceutical ingredient. Although there are potential sources of supply other than our existing manufacturers and suppliers, any new supplier would be required to qualify under applicable regulatory requirements. Principles of Consolidation The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation. Significant Accounting Policies Except as noted below, there have been no material revisions in our significant accounting policies described in Note 2 to the consolidated financial statements included in our Annual Report on Form 10-K Accounting Pronouncements Adopted In December 2019, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2019-12, Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes 2019-12 No. 2019-12 2019-12 2019-12, In August 2020, FASB issued ASU No. 2020-08, Codification Improvement to Subtopic 310-20, 310-20. 2020-08 No. 2020-08 Accounting Pronouncement Issued But Not Yet Adopted In March 2020, FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) 2020-04

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Fair value accounting is applied for all financial assets and liabilities that are recognized or disclosed at f a Assets and liabilities recorded at fair value on a recurring basis in the condensed consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1 Level 2 Level 3 The following table summarizes our financial assets measured at fair value on a recurring basis (in thousands): June 30, 2021 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 358,206 $ 358,206 $ — $ — Corporate debt securities 11,272 — 11,272 — U.S. government agency securities 1,800 — 1,800 — U.S. government securities 5,013 — 5,013 — Total financial assets $ 376,291 $ 358,206 $ 18,085 $ — December 31, 2020 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 486,174 $ 486,174 $ — $ — Corporate debt securities 29,804 — 29,804 — U.S. government agency securities 15,943 — 15,943 — Certificates of deposits 243 — 243 — U.S. government securities 20,136 — 20,136 — Total financial assets $ 552,300 $ 486,174 $ 66,126 $ — We estimate the fair values of our investments in corporate debt securities, government and government related securities and certificates of deposits by taking into consideration valuations obtained from third-party pricing services. The fair value of our marketable securities classified within Level 2 is based upon observable inputs that may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided A-1/P-1

Available-for-Sale Securities

Available-for-Sale Securities	6 Months Ended
	Jun. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Available-for-Sale Securities	4. Available-for-Sale Estimated fair values of available-for-sale available-for-sale June 30,2021 December 31, 2020 Amortized Unrealized Unrealized Estimated Amortized Unrealized Unrealized Estimated Cost Gains (Losses) Value Cost Gains (Losses) Value Financial Assets: Money market funds $ 358,206 $ — $ — $ 358,206 $ 486,174 $ — $ — $ 486,174 Corporate debt securities 11,239 33 — 11,272 29,641 163 — 29,804 U.S. government agency securities 1,800 — — 1,800 15,906 37 — 15,943 Certificates of deposits — — — — 241 2 — 243 U.S. government securities 5,003 10 — 5,013 20,036 100 — 20,136 Total $ 376,248 $ 43 $ — $ 376,291 $ 551,998 $ 302 $ — $ 552,300 The following table summarizes the classification of the available-for-sale June 30, 2021 December 31, 2020 Cash and cash equivalents $ 358,206 $ 486,174 Short-term marketable securities 18,085 66,126 Total $ 376,291 $ 552,300 We do not intend to sell the investments that are in an unrealized loss position, and it is unlikely that we will be required to sell the investments before recovery of their amortized cost basis, which may be maturity.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	5. Balance Sheet Components Inventories Inventories consist of the following (in thousands): June 30, 2021 December 31, 2020 Raw materials $ 9,013 $ 11,273 Work-in-process 36,389 26,994 Finished goods 2,589 1,956 Total inventories $ 47,991 $ 40,223 We have capitalized $408,000 and $557,000 of share-based compensation expense to our inventories for the three months ended June 30, 2021 and 2020, respectively; and $838,000 and $894,000 for the six months ended June 30, 2021 and 2020, respectively. We also have capitalized $45,000 and $141,000 of depreciation expense to our inventories for the three months ended June 30, 2021 and 2020, respectively; and $89,000 and $237,000 for the six months ended June 30, 2021 and 2020, respectively. See Note 8—Share-based Compensation for details on share-based compensation expenses recognized during the three- and six-months Property and Equipment Property and equipment consists of the following (in thousands): June 30, 2021 December 31, 2020 Laboratory equipment $ 13,649 $ 11,922 Computer equipment 3,241 3,023 Leasehold improvements 32,281 32,281 Construction-in-progress 456 517 Total property and equipment 49,627 47,743 Less: accumulated depreciation and amortization (12,852 ) (9,861 ) Property and equipment, net $ 36,775 $ 37,882 Accrued liabilities Accrued liabilities consist of the following (in thousands): June 30, 2021 December 31, 2020 Accrued research and development costs $ 11,976 $ 10,677 Accrued manufacturing costs 13,633 9,125 Accrued professional and consulting services 4,771 4,107 Accrued sales deductions 7,635 6,405 Other 889 819 Total accrued liabilities $ 38,904 $ 31,133

Long-term Debt

Long-term Debt	6 Months Ended
	Jun. 30, 2021
Disclosure Text Block [Abstract]
Long-term Debt	6. Long-term Debt Term Loan On December 17, 2019, we entered into the Loan Agreement, or Term Loan, with funds managed by Pharmakon Advisors LP, which are BioPharma Credit PLC, as collateral agent, Biopharma Credit Investments V (Master) LP, as a lender, and BPCR Limited Partnership, as a lender, and collectively, the Lenders, for a senior secured credit facility consisting of an initial tranche of $75.0 million and the option to draw an additional $75.0 million until December 31, 2020. The first tranche, in the amount of $75.0 million, was funded in connection with the closing date of the Term Loan in December 2019, and the second tranche in the amount of $75.0 million was funded in November 2020. The Term Loan carries a 72-month 3-month We have the option to prepay all or a portion of the borrowed amounts under the Term Loan. If we exercise this option, we must pay a prepayment fee between 1% and 3% of the principal amount being prepaid depending on the timing of the prepayment, or Prepayment Fee. If the prepayment occurs before December 2022, we must also pay an amount equal to the sum of all interest that would have accrued and been payable from date of prepayment through December 2022, or Make Whole Amount. We are obligated to pay an additional fee to the Lenders determined by multiplying the principal amount being paid or prepaid multiplied by 2%, or Paydown Fee, when such payments are made. In the event of default or change in control, all unpaid principal and all accrued and unpaid interest amounts (if any) become immediately due and payable, at which point, we will be subject to the Prepayment Fee, the Make Whole Amount (if any) and the Paydown Fee. Events of default include, but are not limited to, a payment default, a material adverse change, and insolvency. The obligations under the Term Loan are secured by a first priority security interest in and a lien on substantially all of our assets, subject to certain exceptions. Debt issuance costs paid directly to the Lenders of $1.1 million and the other debt issuance costs of $0.5 million were treated as discounts on the Term Loan. These debt discounts along with the Paydown Fee are being amortized or accreted to interest expenses throughout the life of the Term Loan using the effective interest rate method. In addition, we paid the Lenders $1.1 million for the option to draw the additional $75.0 million, which was capitalized as a deferred asset and amortized on a straight-line basis through December 31, 2020. Any remaining unamortized amount was reclassed to debt discount at the time of closing of the second tranche of the Term Loan. We closed the second tranche of the Term Loan in November 2020, and $0.2 million of the unamortized deferred asset related to the option to draw the second tranche was reclassed as the discount on the notes payable. As of June 30, 2021, there were unamortized issuance costs and debt discounts of $1.5 million, which were recorded as a direct deduction from the Term Loan on the condensed consolidated balance sheet. Future payments of principal and interest on the Term Loan as of June 30, 2021 (in thousands): 2021 (six months) $ 6,750 2022 13,500 2023 62,813 2024 58,313 2025 53,813 Total minimum payments 195,189 Less amount representing interest (42,189 ) Less amount representing Paydown Fee (3,000 ) Long-term debt, gross 150,000 Discount on notes payable (1,501 ) Accretion of Paydown Fee 769 Long-term debt $ 149,268

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Leases We have operating leases for our headquarters in South San Francisco, where we have office and research and development laboratory facilities, and equipment. Our leases have remaining lease terms of 1 to 10 years. Most of these leases require monthly lease payments that may be subject to annual increases throughout the lease term. Certain of these leases include renewal options at our election, with renewal terms that can extend the lease term from 1 to 10 years. These optional periods have not been considered in the determination of the right-of-use Lease costs included in operating expense in the condensed consolidated statement of operations and comprehensive loss in relation to these operating leases were $2.4 million and $3.1 million for the three months ended June 30, 2021, and 2020, respectively ; non-lease Supplemental information related to leases for the period reported is as follows (in thousands, except weighted-average remaining lease term and weighted-average discount rate): Six Months Ended 2021 2020 ROU assets obtained in exchange for new operating lease $ — $ 205 Cash paid for amounts included in the measurement of lease liabilities 5,883 2,590 Weighted-average remaining lease term of operating leases (in years) 8.7 9.7 Weighted-average discount rate of operating leases 8.7 % 8.7 % The majority of our lease costs are driven by our operating lease for our headquarters, where we have office and research and development laboratory facilities. In March 2017, we entered into a noncancelable operating lease, or Original Lease, for approximately 67,185 square feet of space in South San Francisco, California, or Prior Premises. The Original Lease term commenced in November 2017 as we gained control over physical access to the Prior Premises for a 10-year In August 2018, we entered into an amendment to the Original Lease, or Lease Amendment, to relocate the leased premises from the Prior Premises to a to-be-constructed 10-year 10-year After relocating to the Substitute Premises, we surrendered and delivered the Prior Premises to the landlord in May 2020, upon which time we had no further obligations with respect to the Prior Premises other than with respect to the Initial Allowance, which we will repay to the landlord in the form of additional monthly rent with interest applied over the term of the Original Lease through November 2027. Upon signing of the Lease Amendment, we re-evaluated As of June 30, 2021, the maturities of our operating lease liabilities were as follows (in thousands): Year ending December 31, Amount 2021 (six months) $ 5,958 2022 12,222 2023 12,584 2024 12,948 2025 13,368 Thereafter 60,507 Total lease payments 117,587 Less: Imputed interest (35,903 ) Present value of operating lease liabilities $ 81,684 The operating leases require us to share in prorated operating expenses and property taxes based upon actual amounts incurred; those amounts are not fixed for future periods and, therefore, are not included in the future commitments listed above. Contingencies In the ordinary course of business, we may be subject to legal claims and regulatory actions that could have a material adverse effect on our business or financial position. We assess our potential liability in such situations by analyzing potential outcomes, assuming various litigation, regulatory and settlement strategies. If we determine a loss is probable and its amount can be reasonably estimated, we accrue an amount equal to the estimated loss. No losses and no provision for a loss contingency have been recorded to date.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation We have three stock-based compensation plans – the Amended and Restated 2017 Inducement Equity Plan, or 2017 Inducement Plan, the Amended and Restated 2015 Stock Option and Incentive Plan, or 2015 Plan, and the 2012 Stock Option and Grant Plan, or 2012 Plan. As of June 30, 2021, there were 2,006,772 shares reserved under the 2017 Inducement Plan and 4,964,617 shares reserved under the 2015 Plan for the future issuance of equity awards. Upon adoption of the 2015 Plan in July 2015, no new awards or grants are permitted under the 2012 Plan. See Note 10 to the Consolidated Financial Statements included in our Annual Report on Form 10-K Stock Options The following summarizes option activity under the 2017 Inducement Plan, 2015 Plan and 2012 Plan: Number of Weighted- Outstanding — December 31, 2020 3,327,330 $ 42.07 Options granted 658,480 43.57 Options exercised (76,338 ) 19.82 Options canceled (170,068 ) 52.52 Outstanding — June 30, 2021 3,739,404 $ 42.32 The fair values of stock options granted to employees were calculated using the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Expected term (in years) 5.3-6.1 5.1-6.1 5.3-6.1 5.1-6.1 Volatility 68.1%-72.2% 71.0%-71.8% 68.1%-72.7% 69.6%-71.8% Risk-free interest rate 1.0%-1.1% 0.4% 0.9%-1.1% 0.4%-1.8% Dividend yield — — — — Restricted Stock Units The following table summarizes activity of restricted stock units, or RSUs, granted to employees with service-based vesting under the 2017 Inducement Plan and 2015 Plan and related information: Number Weighted- Fair Value Non-vested 2,210,356 $ 57.80 RSUs granted 1,409,417 44.28 RSUs vested (379,635 ) 55.06 RSUs forfeited (302,565 ) 53.34 Non-vested 2,937,573 $ 52.13 Market-Condition Awards Granted to Employees Market-Condition RSU Awards Beginning in June 2020, the Compensation Committee of our Board of Directors has granted awards of RSUs to certain of our senior management, including our executive officers, under the 2015 Plan, the vesting of which is contingent upon the achievement of three escalating stock price targets, which we refer to as the Market-Condition RSU Awards. Since June 1, 2020, certain awards have been forfeited in connection with employee terminations and new awards have been granted in connection with new appointments, respectively, with awards for up to an aggregate of 414,700 RSUs outstanding as of June 30, 2021. Upon the achievement of the respective stock price targets, 50% of the RSUs allotted to that tranche will vest, while the remaining 50% will vest on the first anniversary of the date the stock price target was achieved, subject to the employee’s continued employment or other service relationship with us through such vesting date. Under the terms of the awards, if the stock price targets are not achieved for all or some of the tranches on or before June 30, 2024, the unvested awards will be automatically terminated and forfeited. The compensation cost for the RSUs with a market condition is not reversed when the market condition is not satisfied. Stock Price Targets Number of Units Allowed $ 109.20 82,940 $ 145.60 145,145 $ 182.00 186,615 The grant date fair value of the Market-Condition RSU Awards was estimated using a Monte Carlo simulation model, which includes variables such as the expected volatility of the Company’s share price and interest rates to generate potential future outcomes. We recognize the related compensation expense on a straight-line basis over the applicable derived service periods, which are the estimated periods of time that would be required to satisfy the market conditions. The following table summarizes the Market-Condition RSU Awards granted and forfeited during the six months ended June 30, 2021: Number Weighted- Weighted- Aggregate Non-vested 414,700 $ 49.95 1.21 Granted 42,400 13.80 2.23 Forfeited (42,400 ) 49.95 0.71 Non-vested 414,700 $ 46.26 0.76 $ 14,523 The following table summarizes the assumptions used to estimate the fair value of the Market-Condition RSU Awards as of the grant date: Valuation date stock price $ 37.20 Expected term 3.1 years Volatility 66.6 % Risk-free interest rate 0.3 % Dividend yield — At June 30, 2021, total unrecognized compensation expense related to non-vested The weighted average remaining derived service period is million, respectively, in stock-based compensation expense related to the Market-Condition RSU Awards. Stock-Based Compensation Expense Total stock-based compensation recognized by function included in the condensed consolidated statements of operations and comprehensive loss was as follows (in thousands): Three Months Ended Six Months Ended 2021 2020 2021 2020 Research and development $ 4,906 $ 3,430 $ 10,216 $ 8,780 Selling, general and administrative 15,064 13,141 30,134 24,158 Total stock-based compensation expense $ 19,970 $ 16,571 $ 40,350 $ 32,938

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Net Loss per Share	9. Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding for the period. Since we were in a loss position for all periods presented, diluted net loss per share is the same as basic net loss per share for all periods as the inclusion of all potential common shares outstanding would have been anti-dilutive. The following securities were not included in the diluted net loss per share calculations because their effect was anti-dilutive: Three Months Ended Six Months Ended June 30, 2021 2020 2021 2020 Options to purchase common stock 3,739,404 3,574,452 3,739,404 3,574,452 Restricted stock units 3,352,273 2,866,882 3,352,273 2,866,882 Total 7,091,677 6,441,334 7,091,677 6,441,334

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Preparation and Presentation of Financial Information	Basis of Preparation and Presentation of Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and, accordingly, the balance sheet as of December 31, 2020, has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements have been prepared on the same basis as our annual consolidated financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair presentation of our financial information. The results of operations for the six months ended June 30, 2021, are not necessarily indicative of the results to be expected for the year ending December 31, 2021, or for any other interim period or for any other future year. The accompanying unaudited interim condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2020, included in our Annual Report on Form 10-K,
Use of Estimates	Use of Estimates The preparation of the accompanying unaudited interim condensed consolidated financial statements in accordance with U.S. GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of variable consideration and costs and expenses during the reporting period. We base our estimates and assumptions on historical experience when available and on various factors that we believe to be reasonable under the circumstances. We evaluate our estimates and assumptions on an ongoing basis. Our actual results could differ from these estimates under different assumptions or conditions.
Concentration of Risk	Concentration of Risk Credit Risk We invest in a variety of financial instruments and, by our Board approved investment policy, limit the amount of credit exposure with any one issuer, industry or geographic area for investments other than instruments backed by the U.S. federal government. Major Customers We have entered into distribution agreements with certain limited specialty pharmacies and specialty distributors. For the six months ended June 30, 2021, our two largest customers represented approximately 85% of our product revenue and approximately 81% of our accounts receivable balance at June 30, 2021. Major Suppliers We do not currently have any of our own manufacturing facilities, and, therefore, depend on an outsourced manufacturing strategy for the production of Oxbryta for commercial use and for the production of our product candidates for clinical trials. We have contracts in place with one third-party manufacturer that is approved for the commercial production of Oxbryta and two third-party suppliers that are approved for Oxbryta’s active pharmaceutical ingredient. Although there are potential sources of supply other than our existing manufacturers and suppliers, any new supplier would be required to qualify under applicable regulatory requirements.
Principles of Consolidation	Principles of Consolidation The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation.
Significant Accounting Policies	Significant Accounting Policies Except as noted below, there have been no material revisions in our significant accounting policies described in Note 2 to the consolidated financial statements included in our Annual Report on Form 10-K
Accounting Pronouncements Adopted	Accounting Pronouncements Adopted In December 2019, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2019-12, Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes 2019-12 No. 2019-12 2019-12 2019-12, In August 2020, FASB issued ASU No. 2020-08, Codification Improvement to Subtopic 310-20, 310-20. 2020-08 No. 2020-08
Accounting Pronouncement Issued But Not Yet Adopted	Accounting Pronouncement Issued But Not Yet Adopted In March 2020, FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) 2020-04

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis	The following table summarizes our financial assets measured at fair value on a recurring basis (in thousands): June 30, 2021 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 358,206 $ 358,206 $ — $ — Corporate debt securities 11,272 — 11,272 — U.S. government agency securities 1,800 — 1,800 — U.S. government securities 5,013 — 5,013 — Total financial assets $ 376,291 $ 358,206 $ 18,085 $ — December 31, 2020 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 486,174 $ 486,174 $ — $ — Corporate debt securities 29,804 — 29,804 — U.S. government agency securities 15,943 — 15,943 — Certificates of deposits 243 — 243 — U.S. government securities 20,136 — 20,136 — Total financial assets $ 552,300 $ 486,174 $ 66,126 $ —

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	6 Months Ended
	Jun. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Securities	The following table is a summary of available-for-sale June 30,2021 December 31, 2020 Amortized Unrealized Unrealized Estimated Amortized Unrealized Unrealized Estimated Cost Gains (Losses) Value Cost Gains (Losses) Value Financial Assets: Money market funds $ 358,206 $ — $ — $ 358,206 $ 486,174 $ — $ — $ 486,174 Corporate debt securities 11,239 33 — 11,272 29,641 163 — 29,804 U.S. government agency securities 1,800 — — 1,800 15,906 37 — 15,943 Certificates of deposits — — — — 241 2 — 243 U.S. government securities 5,003 10 — 5,013 20,036 100 — 20,136 Total $ 376,248 $ 43 $ — $ 376,291 $ 551,998 $ 302 $ — $ 552,300
Summary of Classification of Available-for-Sale Securities on Consolidated Balance Sheets	The following table summarizes the classification of the available-for-sale June 30, 2021 December 31, 2020 Cash and cash equivalents $ 358,206 $ 486,174 Short-term marketable securities 18,085 66,126 Total $ 376,291 $ 552,300

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventories	Inventories consist of the following (in thousands): June 30, 2021 December 31, 2020 Raw materials $ 9,013 $ 11,273 Work-in-process 36,389 26,994 Finished goods 2,589 1,956 Total inventories $ 47,991 $ 40,223
Property and Equipment, Net	Property and equipment consists of the following (in thousands): June 30, 2021 December 31, 2020 Laboratory equipment $ 13,649 $ 11,922 Computer equipment 3,241 3,023 Leasehold improvements 32,281 32,281 Construction-in-progress 456 517 Total property and equipment 49,627 47,743 Less: accumulated depreciation and amortization (12,852 ) (9,861 ) Property and equipment, net $ 36,775 $ 37,882
Accrued Liabilities	Accrued liabilities consist of the following (in thousands): June 30, 2021 December 31, 2020 Accrued research and development costs $ 11,976 $ 10,677 Accrued manufacturing costs 13,633 9,125 Accrued professional and consulting services 4,771 4,107 Accrued sales deductions 7,635 6,405 Other 889 819 Total accrued liabilities $ 38,904 $ 31,133

Long-term Debt (Tables)

Long-term Debt (Tables)	6 Months Ended
	Jun. 30, 2021
Text Block [Abstract]
Schedule of Future payments of principal and interest on the Term Loan	Future payments of principal and interest on the Term Loan as of June 30, 2021 (in thousands): 2021 (six months) $ 6,750 2022 13,500 2023 62,813 2024 58,313 2025 53,813 Total minimum payments 195,189 Less amount representing interest (42,189 ) Less amount representing Paydown Fee (3,000 ) Long-term debt, gross 150,000 Discount on notes payable (1,501 ) Accretion of Paydown Fee 769 Long-term debt $ 149,268

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Summary of supplemental information related to leases	Supplemental information related to leases for the period reported is as follows (in thousands, except weighted-average remaining lease term and weighted-average discount rate): Six Months Ended 2021 2020 ROU assets obtained in exchange for new operating lease $ — $ 205 Cash paid for amounts included in the measurement of lease liabilities 5,883 2,590 Weighted-average remaining lease term of operating leases (in years) 8.7 9.7 Weighted-average discount rate of operating leases 8.7 % 8.7 %
Schedule of Lessee, Operating Lease, Liability, Maturity	As of June 30, 2021, the maturities of our operating lease liabilities were as follows (in thousands): Year ending December 31, Amount 2021 (six months) $ 5,958 2022 12,222 2023 12,584 2024 12,948 2025 13,368 Thereafter 60,507 Total lease payments 117,587 Less: Imputed interest (35,903 ) Present value of operating lease liabilities $ 81,684

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Stock Option Activity	The following summarizes option activity under the 2017 Inducement Plan, 2015 Plan and 2012 Plan: Number of Weighted- Outstanding — December 31, 2020 3,327,330 $ 42.07 Options granted 658,480 43.57 Options exercised (76,338 ) 19.82 Options canceled (170,068 ) 52.52 Outstanding — June 30, 2021 3,739,404 $ 42.32
Valuation Assumptions for Stock Awards	The fair values of stock options granted to employees were calculated using the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Expected term (in years) 5.3-6.1 5.1-6.1 5.3-6.1 5.1-6.1 Volatility 68.1%-72.2% 71.0%-71.8% 68.1%-72.7% 69.6%-71.8% Risk-free interest rate 1.0%-1.1% 0.4% 0.9%-1.1% 0.4%-1.8% Dividend yield — — — —
Stock-based Compensation Expense Recognized	Total stock-based compensation recognized by function included in the condensed consolidated statements of operations and comprehensive loss was as follows (in thousands): Three Months Ended Six Months Ended 2021 2020 2021 2020 Research and development $ 4,906 $ 3,430 $ 10,216 $ 8,780 Selling, general and administrative 15,064 13,141 30,134 24,158 Total stock-based compensation expense $ 19,970 $ 16,571 $ 40,350 $ 32,938
Summary of Share-based Compensation Arrangements by Share-based Payment Award	The target prices and vesting tranches are set forth in the table below: Stock Price Targets Number of Units Allowed $ 109.20 82,940 $ 145.60 145,145 $ 182.00 186,615
Restricted Stock Units [Member]
Non-Vested Restricted Stock Activity	The following table summarizes activity of restricted stock units, or RSUs, granted to employees with service-based vesting under the 2017 Inducement Plan and 2015 Plan and related information: Number Weighted- Fair Value Non-vested 2,210,356 $ 57.80 RSUs granted 1,409,417 44.28 RSUs vested (379,635 ) 55.06 RSUs forfeited (302,565 ) 53.34 Non-vested 2,937,573 $ 52.13
Market Condition Awards Granted to Employees [Member]
Summary of Activity of Market-Condition Awards	The following table summarizes the Market-Condition RSU Awards granted and forfeited during the six months ended June 30, 2021: Number Weighted- Weighted- Aggregate Non-vested 414,700 $ 49.95 1.21 Granted 42,400 13.80 2.23 Forfeited (42,400 ) 49.95 0.71 Non-vested 414,700 $ 46.26 0.76 $ 14,523
Valuation Assumptions of Market-Condition Awards	The following table summarizes the assumptions used to estimate the fair value of the Market-Condition RSU Awards as of the grant date: Valuation date stock price $ 37.20 Expected term 3.1 years Volatility 66.6 % Risk-free interest rate 0.3 % Dividend yield —

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Potentially Dilutive Securities that were Not Included in Diluted Net Loss per Share Calculations	The following securities were not included in the diluted net loss per share calculations because their effect was anti-dilutive: Three Months Ended Six Months Ended June 30, 2021 2020 2021 2020 Options to purchase common stock 3,739,404 3,574,452 3,739,404 3,574,452 Restricted stock units 3,352,273 2,866,882 3,352,273 2,866,882 Total 7,091,677 6,441,334 7,091,677 6,441,334

Organization and Basis of Prese

Organization and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Cumulative net losses	$ (1,130,991)	$ (986,469)

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - Customer Concentration Risk [Member] - Two Major Customers [Member]	6 Months Ended
	Jun. 30, 2021
Revenue, Product and Service Benchmark [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	85.00%
Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	81.00%

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Assets Measured on Recurring Basis (Detail) - Fair Value Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	$ 376,291	$ 552,300
U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	5,013	20,136
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	358,206	486,174
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	18,085	66,126
Level 2 [Member] | U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	5,013	20,136
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	358,206	486,174
Money Market Funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	358,206	486,174
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	11,272	29,804
Corporate Debt Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	11,272	29,804
U.S. Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	1,800	15,943
U.S. Government Agency Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	$ 1,800	15,943
Certificates of Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value		243
Certificates of Deposits [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value		$ 243

Available-for-Sale Securities -

Available-for-Sale Securities - Summary of Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	$ 376,248	$ 551,998
Available for sale securities, Unrealized Gains	43	302
Available for sale securities, Estimated Fair Value	376,291	552,300
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	11,239	29,641
Available for sale securities, Unrealized Gains	33	163
Available for sale securities, Estimated Fair Value	11,272	29,804
U.S. Government Agency Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	1,800	15,906
Available for sale securities, Unrealized Gains		37
Available for sale securities, Estimated Fair Value	1,800	15,943
Money Market Funds [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	358,206	486,174
Available for sale securities, Estimated Fair Value	358,206	486,174
Certificates of Deposits [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost		241
Available for sale securities, Unrealized Gains		2
Available for sale securities, Estimated Fair Value		243
U.S. Government Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	5,003	20,036
Available for sale securities, Unrealized Gains	10	100
Available for sale securities, Estimated Fair Value	$ 5,013	$ 20,136

Available-for-Sale Securities_2

Available-for-Sale Securities - Summary of Classification of Available-for-Sale Securities on Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Cash and cash equivalents	$ 358,206	$ 486,174
Short-term marketable securities	18,085	66,126
Total	$ 376,291	$ 552,300

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Balance Sheet Components [Abstract]
Raw materials	$ 9,013	$ 11,273
Work-in-process	36,389	26,994
Finished goods	2,589	1,956
Total inventories	$ 47,991	$ 40,223

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 49,627	$ 47,743
Less: accumulated depreciation and amortization	(12,852)	(9,861)
Property and equipment, net	36,775	37,882
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	13,649	11,922
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	3,241	3,023
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	32,281	32,281
Construction-in-Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 456	$ 517

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Balance Sheet Components [Abstract]
Share based compensation expense capitalized	$ 408,000	$ 557,000	$ 838,000	$ 894,000
Capitalized depreciation expenses	$ 45,000	$ 141,000	$ 89,000	$ 237,000

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Balance Sheet Components [Abstract]
Accrued research and development costs	$ 11,976	$ 10,677
Accrued manufacturing costs	13,633	9,125
Accrued professional and consulting services	4,771	4,107
Accrued sales deductions	7,635	6,405
Other	889	819
Total accrued liabilities	$ 38,904	$ 31,133

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Nov. 30, 2020	Dec. 31, 2019	Dec. 17, 2019
Long term debt	$ 149,268		$ 148,815
Debt issuance costs paid	$ 49	$ 130
Unamortized dedt discount				$ 200
Term Loan
Debt additional borrowing capacity				75,000
Debt Instrument, Term	72 months
Debt Instrument, Basis Spread on Variable Rate	7.00%
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	2.00%
Debt Instrument Additional Interest Rate On Debt Default	3.00%
Debt Instrument Periodic Payment Of Interest	Interest on amounts outstanding are payable quarterly in arrears
Debt Instrument Periodic Payment Of Interest Term	39 months
Debt additional paydown fee	2.00%
Debt issuance costs paid	$ 1,100
Other debt issuance cost paid	500
Unamortized issuance costs and debt discounts	1,500
Debt additional paydown fee	$ 1,100
Term Loan | Maximum
Debt prepayment fee	3.00%
Term Loan | Minimum
Debt prepayment fee	1.00%
Secured Debt
Debt maximum borrowing capacity						$ 75,000
Debt additional borrowing capacity						$ 75,000
Long term debt				$ 75,000	$ 75,000

Long-term Debt-Schedule of Futu

Long-term Debt-Schedule of Future payments of principal and interest on the Term Loan (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Contractual Obligation, Fiscal Year Maturity Schedule [Abstract]
2021 (six months)	$ 6,750
2022	13,500
2023	62,813
2024	58,313
2025	53,813
Total minimum payments	195,189
Less amount representing interest	(42,189)
Less amount representing Paydown Fee	(3,000)
Long-term debt, gross	150,000
Discount on notes payable	(1,501)
Accretion of Paydown Fee	769
Long-term debt	$ 149,268	$ 148,815

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended		3 Months Ended		6 Months Ended
	Aug. 31, 2018USD ($)ft²	Mar. 31, 2017ft²	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)
Commitment And Contingencies [Line Items]
Facility size | ft²	164,150	67,185
Initial term		10 years
Future minimum rental payments under the Lease term	$ 121,500,000
Operating lease term	10 years
Operating lease term, optional extension	10 years
Repayment of tenant inducement allowance	$ 4,100,000
Contingency losses					$ 0
Provisions for loss contingency					0
Operating Lease Cost			$ 2,400,000	$ 3,100,000	5,600,000	$ 6,200,000
variable lease cost			1,200,000	600,000	2,000,000	1,300,000
Acceleration of depreciation expenses			$ 0		$ 0
Maximum [Member]
Commitment And Contingencies [Line Items]
Operating lease remaining lease term					10 years
Minimum [Member]
Commitment And Contingencies [Line Items]
Operating lease remaining lease term					1 year
Leasehold Improvements [Member]
Commitment And Contingencies [Line Items]
Property palnt and equipment additions					$ 32,300,000
Depreciation expense				$ 1,900,000		$ 3,800,000
Lease Agreements [Member] | Maximum [Member]
Commitment And Contingencies [Line Items]
Tenant inducement	$ 27,900,000

Commitments and Contingencies_2

Commitments and Contingencies - Supplemental cash flow information (Detail) - Accounting Standards Update 2016-02 [Member] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Commitment And Contingencies [Line Items]
ROU assets obtained in exchange for new operating lease		$ 205
Cash paid for amounts included in the measurement of lease liabilities	$ 5,883	$ 2,590
Weighted-average remaining lease term of operating leases (in years)	8 years 8 months 12 days	9 years 8 months 12 days
Weighted-average discount rate of operating leases	8.70%	8.70%

Commitments and Contingencies_3

Commitments and Contingencies - Lessee Operating Lease Liability Maturity (Detail) $ in Thousands	Jun. 30, 2021USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2021 (six months)	$ 5,958
2022	12,222
2023	12,584
2024	12,948
2025	13,368
Thereafter	60,507
Total lease payments	117,587
Less: Imputed interest	(35,903)
Present value of operating lease liabilities	$ 81,684

Stock-Based Compensation - Plan

Stock-Based Compensation - Plan Summary - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average derived service period		9 months 3 days
Stock-based compensation		$ 41,184	$ 32,938
Market Condition Awards Granted to Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 7,100	7,100
Stock-based compensation	$ 1,500	$ 4,600
2017 Inducement Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance	2,006,772	2,006,772
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance	4,964,617	4,964,617
2015 Plan [Member] | Market Condition Awards Granted to Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Non-vested period	414,700	414,700		414,700

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Detail)	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, outstanding, Number of Options | shares	3,327,330
Options granted, Number of Options | shares	658,480
Options exercised, Number of Options | shares	(76,338)
Options canceled, Number of Options | shares	(170,068)
Ending balance, outstanding, Number of Options | shares	3,739,404
Weighted- Average Exercise Price
Beginning balance, Outstanding, Weighted-Average Exercise Price | $ / shares	$ 42.07
Options granted, Weighted-Average Exercise Price | $ / shares	43.57
Options exercised, Weighted-Average Exercise Price | $ / shares	19.82
Options canceled, Weighted-Average Exercise Price | $ / shares	52.52
Ending balance, Outstanding, Weighted-Average Exercise Price | $ / shares	$ 42.32

Stock-Based Compensation - Valu

Stock-Based Compensation - Valuation Assumptions for Stock Options Granted (Detail) - Stock Options [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	68.10%	71.00%	68.10%	69.60%
Volatility, maximum	72.20%	71.80%	72.70%	71.80%
Risk-free interest rate, minimum	1.00%		0.90%	0.40%
Risk-free interest rate, maximum	1.10%		1.10%	1.80%
Risk-free interest rate		0.40%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 18 days	5 years 1 month 6 days	5 years 3 months 18 days	5 years 1 month 6 days
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of RSU Activity Granted to Employees with Service-Based Vesting (Detail) - 2017 Inducement Plan and 2015 Plan [Member] - RSU [Member]	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance - Non-vested market-condition awards | shares	2,210,356
RSUs granted, Number of RSUs | shares	1,409,417
RSUs vested, Number of RSUs | shares	(379,635)
RSUs forfeited, Number of RSUs | shares	(302,565)
Ending Balance - Non-vested market-condition awards | shares	2,937,573
Beginning Balance - Non-vested units, Weighted-Average Grant Date Fair Value | $ / shares	$ 57.80
RSUs granted, Weighted-Average Grant Date Fair Value | $ / shares	44.28
RSUs vested, Weighted-Average Grant Date Fair Value | $ / shares	55.06
RSUs forfeited, Weighted-Average Grant Date Fair Value | $ / shares	53.34
Ending Balance - Non-vested units, Weighted-Average Grant Date Fair Value | $ / shares	$ 52.13

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Detail) - Market-Condition RSU Awards [Member]	Jun. 30, 2021$ / sharesshares
Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Targets | $ / shares	$ 109.20
Number of Units Allowed | shares	82,940
Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Targets | $ / shares	$ 145.60
Number of Units Allowed | shares	145,145
Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Targets | $ / shares	$ 182
Number of Units Allowed | shares	186,615

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Activity of Market-Condition Awards (Detail) - Market Condition Awards Granted to Employees [Member] - 2015 Plan [Member] - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance - Non-vested market-condition awards	414,700
Number of Units granted	42,400
Number of Units forfeited	(42,400)
Ending Balance - Non-vested market-condition awards	414,700	414,700
Beginning Balance - Non-vested units, Weighted-Average Grant Date Fair Value	$ 49.95
Weighted-Average Grant Date Fair Value granted	13.80
Weighted-Average Grant Date Fair Value forfeited	49.95
Ending Balance - Non-vested units, Weighted-Average Grant Date Fair Value	$ 46.26	$ 49.95
Non-vested units, Weighted-Average remaining vesting period(years)	9 months 3 days	1 year 2 months 15 days
Non-vested units, Weighted-Average remaining vesting period (years) granted	2 years 2 months 23 days
Non-vested units, Weighted-Average remaining vesting period (years) forfeited	8 months 15 days
Non-vested units, Aggregate Intrinsic Value	$ 14,523

Stock-Based Compensation - Va_2

Stock-Based Compensation - Valuation Assumptions of Market-Condition Awards (Detail) - Market Condition Awards Granted To Employees [Member]	6 Months Ended
	Jun. 30, 2021$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Valuation date stock price	$ 37.20
Expected term	3 years 1 month 6 days
Volatility	66.60%
Risk-free interest rate	0.30%
Dividend yield	0.00%

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock-Based Compensation Expense Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 19,970	$ 16,571	$ 40,350	$ 32,938
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	4,906	3,430	10,216	8,780
Selling, general and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 15,064	$ 13,141	$ 30,134	$ 24,158

Net Loss per Share - Potentiall

Net Loss per Share - Potentially Dilutive Securities that were Not Included in Diluted Net Loss per Share Calculations (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	7,091,677	6,441,334	7,091,677	6,441,334
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	3,739,404	3,574,452	3,739,404	3,574,452
RSU [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	3,352,273	2,866,882	3,352,273	2,866,882