Global Blood Therapeutics (GBT) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Cover [Abstract]
Document Type	10-Q
Document Period End Date	Jun. 30, 2020
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		61,360,776
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	2020
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, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 384,716	$ 302,237
Short-term marketable securities	156,014	307,732
Accounts receivable, net	12,471	2,637
Inventories	27,334	1,277
Prepaid expenses and other current assets	13,498	14,114
Total current assets	594,033	627,997
Property and equipment, net	39,668	27,113
Long-term marketable securities	33,479	85,030
Operating lease right-of-use assets	51,580	52,775
Restricted cash	2,395	2,395
Other assets, noncurrent	512	789
Total assets	721,667	796,099
Current liabilities:
Accounts payable	5,690	10,621
Accrued liabilities	43,733	41,358
Accrued compensation	16,463	17,578
Other liabilities, current	3,516	1,896
Total current liabilities	69,402	71,453
Long-term debt	73,775	73,559
Operating lease liabilities, noncurrent	81,903	72,359
Other liabilities, noncurrent	771	34
Total liabilities	225,851	217,405
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized as of June 30, 2020 (unaudited) and December 31, 2019; no shares issued and outstanding
Common stock, $0.001 par value, 150,000,000 shares authorized as of June 30, 2020 (unaudited) and December 31, 2019, respectively; 61,330,987 and 60,644,380 shares issued and outstanding as of June 30, 2020 (unaudited) and December 31, 2019, respectively	61	61
Additional paid-in capital	1,359,310	1,316,795
Accumulated other comprehensive income	1,227	754
Accumulated deficit	(864,782)	(738,916)
Total stockholders' equity	495,816	578,694
Total liabilities and stockholders' equity	$ 721,667	$ 796,099

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
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	61,330,987	60,644,380
Common stock, shares outstanding	61,330,987	60,644,380

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues [Abstract]
Product sales, net	$ 31,501		$ 45,619
Costs and operating expenses:
Cost of sales	377		512
Research and development	34,085	$ 36,010	73,858	$ 70,476
Selling, general and administrative	49,075	24,794	96,736	42,849
Total costs and operating expenses	83,537	60,804	171,106	113,325
Loss from operations	(52,036)	(60,804)	(125,487)	(113,325)
Other income (expense):
Interest income	1,514	3,706	4,370	7,537
Interest expense	(2,282)	(160)	(4,596)	(341)
Other expenses, net	(36)	(63)	(153)	(115)
Total other income (loss), net	(804)	3,483	(379)	7,081
Net loss	(52,840)	(57,321)	(125,866)	(106,244)
Other comprehensive loss:
Net unrealized gain on marketable securities, net of tax	12	615	472	1,239
Comprehensive loss	$ (52,828)	$ (56,706)	$ (125,394)	$ (105,005)
Basic and diluted net loss per common share	$ (0.86)	$ (1.01)	$ (2.06)	$ (1.88)
Weighted-average number of shares used in computing basic and diluted net loss per common share	61,116,707	56,539,760	60,952,269	56,386,560

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 (Loss) [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2018	$ 572,799	$ 56	$ 1,044,941	$ (48)	$ (472,150)
Beginning Balance, Shares at Dec. 31, 2018		55,640,299
Issuance of common stock upon equity offerings, net of issuance costs	21,246		21,246
Issuance of common stock upon equity offerings, net of issuance costs, Shares		511,363
Issuance of common stock upon exercise of stock options	817		817
Issuance of common stock upon exercise of stock options, Shares		52,288
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes	(686)		(686)
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares		78,155
Issuance of common stock pursuant to ESPP purchases	1,128		1,128
Issuance of common stock pursuant to ESPP purchases, Shares		30,745
Vesting of restricted stock purchases	80		80
Vesting of restricted stock purchases, Shares		24,195
Stock-based compensation expense	9,453		9,453
Net unrealized gain on marketable securities	624			624
Net loss	(48,923)				(48,923)
Ending Balance at Mar. 31, 2019	556,538	$ 56	1,076,979	576	(521,073)
Ending Balance, Shares at Mar. 31, 2019		56,337,045
Beginning Balance at Dec. 31, 2018	572,799	$ 56	1,044,941	(48)	(472,150)
Beginning Balance, Shares at Dec. 31, 2018		55,640,299
Net loss	(106,244)
Ending Balance at Jun. 30, 2019	704,190	$ 60	1,281,333	1,191	(578,394)
Ending Balance, Shares at Jun. 30, 2019		59,906,199
Beginning Balance at Mar. 31, 2019	556,538	$ 56	1,076,979	576	(521,073)
Beginning Balance, Shares at Mar. 31, 2019		56,337,045
Issuance of common stock upon equity offerings, net of issuance costs	192,297	$ 3	192,294
Issuance of common stock upon equity offerings, net of issuance costs, Shares		3,375,527
Issuance of common stock upon exercise of stock options	2,332	$ 1	2,331
Issuance of common stock upon exercise of stock options, Shares		123,513
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes	(1,297)		(1,297)
Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares		47,258
Vesting of restricted stock purchases	78		78
Vesting of restricted stock purchases, Shares		22,856
Stock-based compensation expense	10,948		10,948
Net unrealized gain on marketable securities	615			615
Net loss	(57,321)				(57,321)
Ending Balance at Jun. 30, 2019	704,190	$ 60	1,281,333	1,191	(578,394)
Ending Balance, Shares at Jun. 30, 2019		59,906,199
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 expense	16,705		16,705
Net unrealized gain 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
Issuance of common stock upon exercise of stock options, Shares	368,391
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 expense	17,128		17,128
Net unrealized gain on marketable securities	12			12
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

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (125,866)	$ (106,244)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	5,577	4,187
Amortization (accretion) of premium (discount) on marketable securities	(61)	(1,204)
Non-cash interest expense	824
Amortization of operating lease right-of-use assets	580	212
Stock-based compensation	32,938	20,401
Changes in operating assets and liabilities:
Accounts receivables	(9,834)
Inventories	(24,926)
Prepaid expenses and other assets	181	59
Accounts payable	(4,918)	558
Accrued liabilities	(1,326)	6,136
Accrued compensation	(1,114)	(1,795)
Other liabilities, current	156
Operating lease liabilities	1,686	(563)
Net cash used in operating activities	(126,103)	(78,253)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(3,918)	(548)
Purchase of marketable securities	(57,936)	(195,297)
Maturities of marketable securities	261,738	120,923
Net cash provided by (used in) investing activities	199,884	(74,922)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock in public offering, net of issuance costs		213,989
Proceeds from issuance of common stock in settlement of employee stock purchase plan and exercise of stock options	11,000	4,266
Payments of debt issuance costs	(130)
Tax paid related to net share settlement of equity awards	(2,172)	(1,983)
Net cash provided by financing activities	8,698	216,272
Net increase (decrease) in cash, cash equivalents and restricted cash	82,479	63,097
Cash, cash equivalents and restricted cash at beginning of period	304,632	277,752
Cash, cash equivalents and restricted cash at end of period	387,111	340,849
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest	3,419
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Leasehold improvements paid for by landlord	10,709	851
Accrued purchase of property and equipment	3,773	147
Accrued issuance costs	$ (85)	$ 446

Organization and Basis of Prese

Organization and Basis of Presentation	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation 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 commercial launch of Oxbryta, research and development and business development activities. Since inception through June 30, 2020, we have incurred cumulative net losses of $864.8 million. 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, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Preparation 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, 2019 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, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 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, 2019 included in our Annual Report on Form 10-K, Use of Estimates The preparation of the accompanying 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 revenues 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 a specialty distributor. For the six months ended June 30, 2020, our two largest customers represented approximately 95% of our product revenue and approximately 94% of our accounts receivable balance at June 30, 2020. 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 one third-party supplier that is 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 August 2018, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2018-15, Intangibles—Goodwill and Other—Internal-Use 350-40), Arrangement That Is a Service Contract 2018-15. No. 2018-15 internal-use 350-40 No. 2018-15 In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) No. 2018-13 No. 2018-13. No. 2018-13 In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) Available-for-sale available-for-sale No. 2016-13

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
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 fair value in the consolidated financial statements on a recurring basis (at least annually). Our financial instruments consist of cash and cash equivalents, marketable securities, accounts receivables, accounts payable and accrued liabilities. Cash and cash equivalents, marketable securities and restricted cash are reported at their respective fair values on our condensed consolidated balance sheets. The remaining financial instruments are reported on our condensed consolidated balance sheets at cost that approximate current fair values due to their relatively short maturities. 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 – Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 – Level 3 – Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. The following table summarizes our financial assets measured at fair value on a recurring basis (in thousands): June 30, 2020 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 384,515 $ 384,515 $ — $ — Corporate debt securities 84,046 — 84,046 — U.S. government agency securities 43,524 — 43,524 — Certificates of deposits 3,899 — 3,899 — U.S. government securities 58,025 — 58,025 — Total financial assets $ 574,009 $ 384,515 $ 189,494 $ — December 31, 2019 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 250,535 $ 250,535 $ — $ — Corporate debt securities 152,149 — 152,149 — U.S. government agency securities 95,032 — 95,032 — Certificates of deposits 6,282 — 6,282 — U.S. government securities 140,244 — 140,244 — Total financial assets $ 644,242 $ 250,535 $ 393,707 $ — 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, 2020
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, 2020 December 31, 2019 Amortized Unrealized Unrealized Estimated Fair Amortized Unrealized Unrealized Estimated Fair Financial Assets: Money market funds $ 384,515 $ — $ — $ 384,515 $ 250,535 $ — $ — $ 250,535 Corporate debt securities 83,385 661 — 84,046 151,773 384 (8 ) 152,149 U.S. government agency securities 43,418 108 (2 ) 43,524 94,963 73 (4 ) 95,032 Certificates of deposits 3,868 31 — 3,899 6,239 43 — 6,282 U.S. government securities 57,596 429 — 58,025 139,978 266 — 140,244 Total $ 572,782 $ 1,229 $ (2 ) $ 574,009 $ 643,488 $ 766 $ (12 ) $ 644,242 The following table summarizes the classification of the available-for-sale June 30, 2020 December 31, 2019 Cash and cash equivalents $ 384,516 $ 251,480 Short-term marketable securities 156,014 307,732 Long-term marketable securities 33,479 85,030 Total $ 574,009 $ 644,242 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. We have determined that the gross unrealized losses on our marketable securities were temporary in nature during the periods presented.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	5. Balance Sheet Components Inventories We began capitalizing inventories in November 2019 once the FDA approved Oxbryta. Inventories consist of the following (in thousands): June 30, 2020 December 31, 2019 Raw materials $ 10,210 $ 700 Work-in-process 15,617 525 Finished goods 1,507 52 Total inventories $ 27,334 $ 1,277 Property and Equipment, Net Property and equipment consists of the following June 30, 2020 December 31, 2019 Laboratory equipment $ 11,612 $ 8,314 Computer equipment 2,600 2,224 Leasehold improvements 32,231 13,785 Construction-in-progress 515 19,289 Total property and equipment 46,958 43,612 Less: accumulated depreciation and amortization (7,290 ) (16,499 ) Property and equipment, net $ 39,668 $ 27,113 Accrued liabilities Accrued liabilities consist of the following (in thousands): June 30, 2020 December 31, 2019 Accrued research and development costs $ 6,951 $ 26,480 Accrued manufacturing costs 23,782 9,466 Accrued professional and consulting services 3,283 4,564 Accrued sales deductions 5,302 529 Other 4,415 319 Total accrued liabilities $ 43,733 $ 41,358 Other liabilities, current Other liabilities consist of the following (in thousands): June 30, 2020 December 31, 2019 Operating lease liabilities, current $ 3,486 $ 1,866 Other payable 30 30 Total other liabilities, current $ 3,516 $ 1,896

Long-term Debt

Long-term Debt	6 Months Ended
	Jun. 30, 2020
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. In June 2020, in accordance with the terms of the Loan Agreement, we provided notification to Lenders of our intention to draw the second tranche of the Term Loan, in the amount of $75.0 million, prior to December 31, 2020, subject to certain closing conditions. As of June 30, 2020, the second tranche of the Term Loan has not been drawn. The Term Loan carries a 72-month annum 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 $0.4 million were accounted for 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. As of June 30, 2020, there were unamortized issuance costs and debt discounts of $1.4 million, which were recorded as a direct deduction from the Term Loan on the condensed consolidated balance sheet. In addition, we paid the Lenders $1.1 million for the option to draw the additional $75 million, which was capitalized as a deferred asset and which is included in other assets, current and amortized on a straight-line basis through December 31, 2020. As of June 30, 2020, the unamortized fee for the option to draw the additional funds was $0.6 million. Future payments of principal and interest on the Term Loan as of June 30, 2020 were as follows (in thousands): Year ending December 31, Amount 2020 (six months) $ 3,375 2021 6,750 2022 6,750 2023 31,406 2024 29,156 2025 26,906 Total minimum payments 104,343 Less amount representing interest (27,843 ) Less amount representing Paydown Fee (1,500 ) Long-term debt, gross 75,000 Discount on notes payable (1,411 ) Accretion of Paydown Fee 186 Long-term debt $ 73,775

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Leases We have operating leases for our headquarters, 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 expenses in the consolidated statement of operations in relation to these operating leases were $3.1 million and $1.4 million for the three months ended June 30, 2020 and 2019, respectively; and $6.2 million and $3.3 million for the six months ended June 30, 2020 and 2019, respectively. Included in these lease costs were variable lease costs, which were not included within the measurement of our operating ROU assets and operating lease liabilities in the amount of $0.6 million and $0.4 million for the three months ended June 30, 2020 and 2019, respectively; and $1.3 million and $1.3 million for the six months ended June 30, 2020 and 2019, respectively. The variable lease cost is comprised primarily of our proportionate share of operating expenses, property taxes, and insurance in relation with our facility lease. These costs are classified as operating lease expense due to our election to not separate lease and non-lease components. Supplemental cash flow 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 June 30, 2020 2019 ROU assets obtained in exchange for new operating lease $ 205 $ 14,177 Cash paid for amounts included in the measurement of lease liabilities 2,590 2,235 Weighted-average remaining lease term of operating leases (in years) 9.7 8.4 Weighted-average discount rate of operating leases 8.7 % 13.2 % The majority of our lease costs are driven by our operating lease for our headquarters in South San Francisco, 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. We acquired $11.1 million of leasehold improvements at the Prior Premises with the tenant inducement allowance provided under the Original Lease. We are required to repay $1.7 million of the tenant inducement allowance , or Initial Allowance, to the landlord in the form of additional monthly rent with interest applied over the term of the Original Lease. In August 2018, we entered into an amendment to the Original to-be-constructed 10-year 10-year We vacated the Prior Premises and 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 As of June 30, 2020, the maturities of our operating lease liabilities were as follows (in thousands): Year ending December 31, Amount 2020 ( six $ 4,837 2021 11,822 2022 12,202 2023 12,564 2024 12,927 2025 13,347 Thereafter 61,146 Total lease payments 128,845 Less: Imputed interest (43,456 ) Present value of operating lease liabilities $ 85,389 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, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	8. Stock-Based Compensation We have three stock-based compensation plans – Amended and Restated 10-K Stock Options The following summarizes option activity under the 2017 Inducement Plan, 2015 Plan and 2012 Plan: Number of Weighted- Outstanding 3,573,860 $ 36.24 Options granted 666,633 65.91 Options exercised (368,391 ) 24.39 Options canceled (297,650 ) 52.93 Outstanding 3,574,452 $ 41.61 The fair values of stock options granted to employees were calculated using the following assumptions: Three Months Ended Six Months Ended 2020 2019 2020 2019 Expected term (in years) 5.1-6.1 5.3-6.1 5.1-6.1 5.3-6.1 Volatility 71.0%-71.8% 70.5%-71.7% 69.6%-71.8% 70.5%-72.2% Risk-free interest rate 0.4% 1.8%-2.4% 0.4%-1.8% 1.8%-2.6% 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- Non-vested 1,848,772 $ 49.19 RSUs granted 1,183,637 66.28 RSUs vested (304,495 ) 48.25 RSUs forfeited (275,732 ) 54.75 Non-vested 2,452,182 $ 56.93 Market-Condition RSUs Granted to Employees The Compensation Committee of granted, effective June 1, 2020, an aggregate 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. Upon the achievement of the respective stock price targets, fifty percent of the RSUs allotted to that tranche will vest, while the remaining fifty percent 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 the Company 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. The target prices and vesting tranches are set forth in the table below: Stock Price Targets Number of Units Allotted $109.20 82,940 $145.60 145,145 $182.00 186,615 The grant date fair value of the market-condition 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 activity of the market-condition awards under the 2015 Plan and related information (in thousands, except share, per share amounts and vesting period): Number U Weighted- Weighted- Aggregate Non-vested — $ — — Granted 414,700 49.95 Vested — — Forfeited — — Non-vested 414,700 $ 49.95 1.71 $ 26,180 The following table summarizes the assumptions used to estimate the fair value of the market-condition awards as of the grant date Valuation date stock price $ 68.67 Volatility 68.1 % Risk-free interest rate 0.26 % Dividend yield — At June 30, 2020 , non-vested three months 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 2020 2019 2020 2019 Research and development $ 3,430 $ 4,715 $ 8,780 $ 8,738 Selling, general and administrative 13,141 6,233 24,158 11,663 Total stock-based compensation expense $ 16,571 $ 10,948 $ 32,938 $ 20,401

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2020
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 2020 2019 2020 2019 Options to purchase common stock 3,574,452 3,758,846 3,574,452 3,758,846 Restricted stock units 2,866,882 1,730,348 2,866,882 1,730,348 Total 6,441,334 5,489,194 6,441,334 5,489,194

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Preparation 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, 2019 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, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 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, 2019 included in our Annual Report on Form 10-K,
Use of Estimates	Use of Estimates The preparation of the accompanying 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 revenues 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 a specialty distributor. For the six months ended June 30, 2020, our two largest customers represented approximately 95% of our product revenue and approximately 94% of our accounts receivable balance at June 30, 2020. 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 one third-party supplier that is 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 August 2018, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2018-15, Intangibles—Goodwill and Other—Internal-Use 350-40), Arrangement That Is a Service Contract 2018-15. No. 2018-15 internal-use 350-40 No. 2018-15 In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) No. 2018-13 No. 2018-13. No. 2018-13 In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326) Available-for-sale available-for-sale No. 2016-13

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 384,515 $ 384,515 $ — $ — Corporate debt securities 84,046 — 84,046 — U.S. government agency securities 43,524 — 43,524 — Certificates of deposits 3,899 — 3,899 — U.S. government securities 58,025 — 58,025 — Total financial assets $ 574,009 $ 384,515 $ 189,494 $ — December 31, 2019 Total Level 1 Level 2 Level 3 Financial Assets: Money market funds $ 250,535 $ 250,535 $ — $ — Corporate debt securities 152,149 — 152,149 — U.S. government agency securities 95,032 — 95,032 — Certificates of deposits 6,282 — 6,282 — U.S. government securities 140,244 — 140,244 — Total financial assets $ 644,242 $ 250,535 $ 393,707 $ —

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	6 Months Ended
	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Securities	The following table is a summary of available-for-sale June 30, 2020 December 31, 2019 Amortized Unrealized Unrealized Estimated Fair Amortized Unrealized Unrealized Estimated Fair Financial Assets: Money market funds $ 384,515 $ — $ — $ 384,515 $ 250,535 $ — $ — $ 250,535 Corporate debt securities 83,385 661 — 84,046 151,773 384 (8 ) 152,149 U.S. government agency securities 43,418 108 (2 ) 43,524 94,963 73 (4 ) 95,032 Certificates of deposits 3,868 31 — 3,899 6,239 43 — 6,282 U.S. government securities 57,596 429 — 58,025 139,978 266 — 140,244 Total $ 572,782 $ 1,229 $ (2 ) $ 574,009 $ 643,488 $ 766 $ (12 ) $ 644,242
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, 2020 December 31, 2019 Cash and cash equivalents $ 384,516 $ 251,480 Short-term marketable securities 156,014 307,732 Long-term marketable securities 33,479 85,030 Total $ 574,009 $ 644,242

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventories	We began capitalizing inventories in November 2019 once the FDA approved Oxbryta. Inventories consist of the following (in thousands): June 30, 2020 December 31, 2019 Raw materials $ 10,210 $ 700 Work-in-process 15,617 525 Finished goods 1,507 52 Total inventories $ 27,334 $ 1,277
Property and Equipment, Net	Property and Equipment, Net Property and equipment consists of the following June 30, 2020 December 31, 2019 Laboratory equipment $ 11,612 $ 8,314 Computer equipment 2,600 2,224 Leasehold improvements 32,231 13,785 Construction-in-progress 515 19,289 Total property and equipment 46,958 43,612 Less: accumulated depreciation and amortization (7,290 ) (16,499 ) Property and equipment, net $ 39,668 $ 27,113
Accrued Liabilities	Accrued liabilities Accrued liabilities consist of the following (in thousands): June 30, 2020 December 31, 2019 Accrued research and development costs $ 6,951 $ 26,480 Accrued manufacturing costs 23,782 9,466 Accrued professional and consulting services 3,283 4,564 Accrued sales deductions 5,302 529 Other 4,415 319 Total accrued liabilities $ 43,733 $ 41,358
Other Liabilities	Other liabilities, current Other liabilities consist of the following (in thousands): June 30, 2020 December 31, 2019 Operating lease liabilities, current $ 3,486 $ 1,866 Other payable 30 30 Total other liabilities, current $ 3,516 $ 1,896

Long-term Debt (Table)

Long-term Debt (Table)	6 Months Ended
	Jun. 30, 2020
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, 2020 were as follows (in thousands): Year ending December 31, Amount 2020 (six months) $ 3,375 2021 6,750 2022 6,750 2023 31,406 2024 29,156 2025 26,906 Total minimum payments 104,343 Less amount representing interest (27,843 ) Less amount representing Paydown Fee (1,500 ) Long-term debt, gross 75,000 Discount on notes payable (1,411 ) Accretion of Paydown Fee 186 Long-term debt $ 73,775

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Summary of supplemental cash flow information related to leases	Supplemental cash flow 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 June 30, 2020 2019 ROU assets obtained in exchange for new operating lease $ 205 $ 14,177 Cash paid for amounts included in the measurement of lease liabilities 2,590 2,235 Weighted-average remaining lease term of operating leases (in years) 9.7 8.4 Weighted-average discount rate of operating leases 8.7 % 13.2 %
Schedule of Lessee, Operating Lease, Liability, Maturity	As of June 30, 2020, the maturities of our operating lease liabilities were as follows (in thousands): Year ending December 31, Amount 2020 ( six $ 4,837 2021 11,822 2022 12,202 2023 12,564 2024 12,927 2025 13,347 Thereafter 61,146 Total lease payments 128,845 Less: Imputed interest (43,456 ) Present value of operating lease liabilities $ 85,389

Stock-based Compensation (Table

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Stock Option Activity	The following summarizes option activity under the 2017 Inducement Plan, 2015 Plan and 2012 Plan: Number of Weighted- Outstanding 3,573,860 $ 36.24 Options granted 666,633 65.91 Options exercised (368,391 ) 24.39 Options canceled (297,650 ) 52.93 Outstanding 3,574,452 $ 41.61
Valuation Assumptions for Stock Awards	The fair values of stock options granted to employees were calculated using the following assumptions: Three Months Ended Six Months Ended 2020 2019 2020 2019 Expected term (in years) 5.1-6.1 5.3-6.1 5.1-6.1 5.3-6.1 Volatility 71.0%-71.8% 70.5%-71.7% 69.6%-71.8% 70.5%-72.2% Risk-free interest rate 0.4% 1.8%-2.4% 0.4%-1.8% 1.8%-2.6% Dividend yield — — — —
Summary of Activity of Market-Condition Awards	The following table summarizes activity of the market-condition awards under the 2015 Plan and related information (in thousands, except share, per share amounts and vesting period): Number U Weighted- Weighted- Aggregate Non-vested — $ — — Granted 414,700 49.95 Vested — — Forfeited — — Non-vested 414,700 $ 49.95 1.71 $ 26,180
Valuation Assumptions of Market-Condition Awards	The following table summarizes the assumptions used to estimate the fair value of the market-condition awards as of the grant date Valuation date stock price $ 68.67 Volatility 68.1 % Risk-free interest rate 0.26 % 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 2020 2019 2020 2019 Research and development $ 3,430 $ 4,715 $ 8,780 $ 8,738 Selling, general and administrative 13,141 6,233 24,158 11,663 Total stock-based compensation expense $ 16,571 $ 10,948 $ 32,938 $ 20,401
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 Allotted $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- Non-vested 1,848,772 $ 49.19 RSUs granted 1,183,637 66.28 RSUs vested (304,495 ) 48.25 RSUs forfeited (275,732 ) 54.75 Non-vested 2,452,182 $ 56.93

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2020
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 2020 2019 2020 2019 Options to purchase common stock 3,574,452 3,758,846 3,574,452 3,758,846 Restricted stock units 2,866,882 1,730,348 2,866,882 1,730,348 Total 6,441,334 5,489,194 6,441,334 5,489,194

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Cumulative net losses	$ 864,782	$ 738,916

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, 2020
Revenue, Product and Service Benchmark [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	95.00%
Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	94.00%

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, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	$ 574,009	$ 644,242
U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	58,025	140,244
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	384,515	250,535
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	189,494	393,707
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	58,025	140,244
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	384,515	250,535
Money Market Funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	384,515	250,535
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	84,046	152,149
Corporate Debt Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	84,046	152,149
U.S. Government Agency Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	43,524	95,032
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	43,524	95,032
Certificates of Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	3,899	6,282
Certificates of Deposits [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	$ 3,899	$ 6,282

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, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	$ 572,782	$ 643,488
Available for sale securities, Unrealized Gains	1,229	766
Available for sale securities, Unrealized (Losses)	(2)	(12)
Available for sale securities, Estimated Fair Value	574,009	644,242
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	83,385	151,773
Available for sale securities, Unrealized Gains	661	384
Available for sale securities, Unrealized (Losses)		(8)
Available for sale securities, Estimated Fair Value	84,046	152,149
U.S. Government Agency Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	43,418	94,963
Available for sale securities, Unrealized Gains	108	73
Available for sale securities, Unrealized (Losses)	(2)	(4)
Available for sale securities, Estimated Fair Value	43,524	95,032
Money Market Funds [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	384,515	250,535
Available for sale securities, Estimated Fair Value	384,515	250,535
Certificates of Deposits [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	3,868	6,239
Available for sale securities, Unrealized Gains	31	43
Available for sale securities, Unrealized (Losses)
Available for sale securities, Estimated Fair Value	3,899	6,282
U.S. Government Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for sale securities, Amortized Cost	57,596	139,978
Available for sale securities, Unrealized Gains	429	266
Available for sale securities, Unrealized (Losses)
Available for sale securities, Estimated Fair Value	$ 58,025	$ 140,244

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, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Cash and cash equivalents	$ 384,516	$ 251,480
Short-term marketable securities	156,014	307,732
Long-term marketable securities	33,479	85,030
Total	$ 574,009	$ 644,242

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Raw materials	$ 10,210	$ 700
Work-in-process	15,617	525
Finished goods	1,507	52
Inventories	$ 27,334	$ 1,277

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 46,958	$ 43,612
Less: accumulated depreciation and amortization	(7,290)	(16,499)
Property and equipment, net	39,668	27,113
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	11,612	8,314
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	2,600	2,224
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	32,231	13,785
Construction-in-Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 515	$ 19,289

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Accrued research and development costs	$ 6,951	$ 26,480
Accrued manufacturing costs	23,782	9,466
Accrued professional and consulting services	3,283	4,564
Accrued sales deductions	5,302	529
Other	4,415	319
Total accrued liabilities	$ 43,733	$ 41,358

Balance Sheet Components - Othe

Balance Sheet Components - Other Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Operating lease liabilities, current	$ 3,486	$ 1,866
Other payable	30	30
Total other liabilities, current	$ 3,516	$ 1,896

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Dec. 17, 2019
Long term debt	$ 73,775	$ 73,559
Debt issuance costs paid	130
Unamortized fee	600
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	400
Unamortized issuance costs and debt discounts	1,400
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, 2020	Dec. 31, 2019
Contractual Obligation, Fiscal Year Maturity Schedule [Abstract]
2020 (six months)	$ 3,375
2021	6,750
2022	6,750
2023	31,406
2024	29,156
2025	26,906
Total minimum payments	104,343
Less amount representing interest	(27,843)
Less amount representing Paydown Fee	(1,500)
Long-term debt, gross	75,000
Discount on notes payable	(1,411)
Accretion of Paydown Fee	186
Long-term debt	$ 73,775	$ 73,559

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended		3 Months Ended		6 Months Ended
	Aug. 31, 2018USD ($)ft²	Mar. 31, 2017USD ($)ft²	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)
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			$ 3,100,000	$ 1,400,000	6,200,000	$ 3,300,000
variable lease cost			$ 600,000	$ 400,000	1,300,000	1,300,000
Repayemnt of tenant inducement allowance to the landlord		$ 1,700,000
Acceleration of depreciation expenses					$ 3,800,000	$ 3,400,000
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					$ 32,200,000
Lease Agreements [Member]
Commitment And Contingencies [Line Items]
leasehold improvements Acquired		$ 11,100,000
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) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Commitment And Contingencies [Line Items]
ROU assets obtained in exchange for new operating lease	$ 205	$ 14,177
Cash paid for amounts included in the measurement of lease liabilities	$ 2,590	$ 2,235
Weighted-average remaining lease term of operating leases (in years)	9 years 8 months 12 days	8 years 4 months 24 days
Weighted-average discount rate of operating leases	8.70%	13.20%

Commitments and Contingencies_3

Commitments and Contingencies - Lessee Operating Lease Liability Maturity (Detail) $ in Thousands	Jun. 30, 2020USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2020 (six months)	$ 4,837
2021	11,822
2022	12,202
2023	12,564
2024	12,927
2025	13,347
Thereafter	61,146
Total lease payments	128,845
Less: Imputed interest	(43,456)
Present value of operating lease liabilities	$ 85,389

Stock-based Compensation - Plan

Stock-based Compensation - Plan Summary - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 01, 2020	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
weighted average derived service period			1 year 9 months 14 days
Stock-based compensation			$ 32,938	$ 20,401
Market Condition Awards Granted to Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense		$ 19,700	$ 19,700
Stock-based compensation		$ 1,100
2017 Inducement Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance		1,628,836	1,628,836
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance		4,522,527	4,522,527
2015 Plan [Member] | RSU [Member] | Senior Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted in period	414,700
2015 Plan [Member] | Market Condition Awards Granted to Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted in period			414,700

Stock-based Compensation - Stoc

Stock-based Compensation - Stock Option Activity (Detail)	6 Months Ended
	Jun. 30, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, outstanding, Number of Options | shares	3,573,860
Options granted, Number of Options | shares	666,633
Options exercised, Number of Options | shares	(368,391)
Options canceled, Number of Options | shares	(297,650)
Ending balance, outstanding, Number of Options | shares	3,574,452
Weighted- Average Exercise Price
Beginning balance, Outstanding, Weighted-Average Exercise Price | $ / shares	$ 36.24
Options granted, Weighted-Average Exercise Price | $ / shares	65.91
Options exercised, Weighted-Average Exercise Price | $ / shares	24.39
Options canceled, Weighted-Average Exercise Price | $ / shares	52.93
Ending balance, Outstanding, Weighted-Average Exercise Price | $ / shares	$ 41.61

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	71.00%	70.50%	69.60%	70.50%
Volatility, maximum	71.80%	71.70%	71.80%	72.20%
Risk-free interest rate	0.40%
Risk-free interest rate, minimum		1.80%	0.40%	1.80%
Risk-free interest rate, maximum		2.40%	1.80%	2.60%
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 1 month 6 days	5 years 3 months 18 days	5 years 1 month 6 days	5 years 3 months 18 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, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance - Non-vested market-condition awards | shares	1,848,772
RSUs granted, Number of RSUs | shares	1,183,637
RSUs vested, Number of RSUs | shares	(304,495)
RSUs forfeited, Number of RSUs | shares	(275,732)
Ending Balance - Non-vested market-condition awards | shares	2,452,182
Beginning Balance - Non-vested units, Weighted-Average Grant Date Fair Value | $ / shares	$ 49.19
RSUs granted, Weighted-Average Grant Date Fair Value | $ / shares	66.28
RSUs vested, Weighted-Average Grant Date Fair Value | $ / shares	48.25
RSUs forfeited, Weighted-Average Grant Date Fair Value | $ / shares	54.75
Ending Balance - Non-vested units, Weighted-Average Grant Date Fair Value | $ / shares	$ 56.93

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Detail)	Jun. 30, 2020$ / sharesshares
Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Price Targets | $ / shares	$ 109.20
Number of Units Allotted | 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 Allotted | 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 Allotted | 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] $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance - Non-vested market-condition awards	0
Number of Units granted	414,700
Ending Balance - Non-vested market-condition awards	414,700
Weighted-Average Grant Date Fair Value granted | $ / shares	$ 49.95
Ending Balance - Non-vested units, Weighted-Average Grant Date Fair Value | $ / shares	$ 49.95
Non-vested units, Weighted-Average remaining vesting period(years)	1 year 8 months 15 days
Non-vested units, Aggregate Intrinsic Value | $	$ 26,180

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	9 Months Ended
	Jun. 30, 2020$ / shares	Jun. 30, 2020$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Valuation date stock price	$ 68,670	$ 68,670
Volatility		68.10%
Risk-free interest rate		0.26%
Dividend yield

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 16,571	$ 10,948	$ 32,938	$ 20,401
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	3,430	4,715	8,780	8,738
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 13,141	$ 6,233	$ 24,158	$ 11,663

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	6,441,334	5,489,194	6,441,334	5,489,194
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	3,574,452	3,758,846	3,574,452	3,758,846
RSU [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	2,866,882	1,730,348	2,866,882	1,730,348