DURECT (DRRX) 10-Q 30 Jul 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Jul. 28, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Title of 12(b) Security	Common Stock $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Trading Symbol	DRRX
Entity Registrant Name	DURECT CORP
Entity Central Index Key	0001082038
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		227,496,180
Entity Shell Company	false
Entity Incorporation, State or Country Code	DE
Entity File Number	000-31615
Entity Tax Identification Number	94-3297098
Entity Address, Address Line One	10260 Bubb Road
Entity Address, City or Town	Cupertino
Entity Address, State or Province	CA
Entity Current Reporting Status	Yes
Entity Address, Postal Zip Code	95014
City Area Code	408
Local Phone Number	777-1417
Document Quarterly Report	true
Document Transition Report	false

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 56,073	$ 21,312
Cash held in escrow		14,979
Short-term investments	32,357	19,421
Accounts receivable (net of allowances of $16 at June 30, 2021 and $72 at December 31, 2020)	816	940
Inventories, net	1,918	1,864
Prepaid expenses and other current assets	4,192	4,545
Total current assets	95,356	63,061
Property and equipment, net	211	251
Operating lease right-of-use assets	4,120	4,749
Goodwill	6,169	6,169
Long-term investments		1,000
Long-term restricted investments	150	150
Other long-term assets	261	261
Total assets	106,267	75,641
Current liabilities:
Accounts payable	1,086	1,678
Accrued liabilities	5,114	5,801
Contract research liabilities	192	545
Deferred revenue, current portion	5
Term loan, current portion, net		884
Operating lease liabilities, current portion	1,821	1,795
Total current liabilities	8,218	10,703
Deferred revenue, non-current portion	812	812
Operating lease liabilities, non-current portion	2,541	3,202
Term loan, non-current portion, net	20,360	19,936
Other long-term liabilities	873	873
Commitments and contingencies
Stockholders’ equity:
Common stock	23	20
Additional paid-in capital	582,505	529,884
Accumulated other comprehensive loss	(1)	(5)
Accumulated deficit	(509,064)	(489,784)
Stockholders’ equity	73,463	40,115
Total liabilities and stockholders’ equity	$ 106,267	$ 75,641

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Allowances for accounts receivable	$ 16	$ 72

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive (Loss) Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Total revenues	$ 2,303	$ 24,498	$ 4,515	$ 26,093
Operating expenses:
Cost of product revenues	$ 359	$ 253	$ 711	$ 649
Type of cost, good or service [extensible list]	Product Revenue, Net [Member]	Product Revenue, Net [Member]	Product Revenue, Net [Member]	Product Revenue, Net [Member]
Research and development	$ 7,433	$ 6,567	$ 15,408	$ 14,154
Selling, general and administrative	3,168	3,337	6,699	6,768
Total operating expenses	10,960	10,157	22,818	21,571
(Loss) income from operations	(8,657)	14,341	(18,303)	4,522
Other income (expense):
Interest and other income	39	135	76	393
Interest expense	(528)	(552)	(1,053)	(1,144)
Net other expense	$ (489)	$ (417)	$ (977)	$ (751)
(Loss) income from continuing operations	$ (9,146)	$ 13,924	$ (19,280)	$ 3,771
Income from discontinued operations		$ 414		$ 619
Net (loss) income	$ (9,146)	14,338	$ (19,280)	4,390
Net change in unrealized gain on available-for-sale securities, net of reclassification adjustments and taxes	13	89	4	74
Total comprehensive (loss) income	$ (9,133)	$ 14,427	$ (19,276)	$ 4,464
Net (loss) income per share
Weighted-average shares used in computing net (loss) income per share, basic	227,428	196,866	222,510	196,306
Weighted-average shares used in computing net (loss) income per share, diluted	227,428	207,477	222,510	206,111
Basic and diluted
(Loss) income from continuing operations	$ (0.04)	$ 0.07	$ (0.09)	$ 0.02
Income from discontinued operations		$ 0		$ 0
Collaborative Research and Development and Other Revenue [Member]
Total revenues	$ 735	$ 23,347	$ 1,309	$ 23,317
Product Revenue, Net [Member]
Total revenues	$ 1,568	$ 1,151	$ 3,206	$ 2,776

Condensed Statements of Stockho

Condensed 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, 2019	$ 22,860	$ 19	$ 512,046	$ (3)	$ (489,202)
Beginning balance, shares at Dec. 31, 2019		195,257,000
Stock-based compensation expense from stock options and ESPP shares	761		761
Fully vested options issued to settle accrued liabilities	416		416
Net income (loss)	(9,948)				(9,948)
Unrealized gain (loss) on available-for-sale securities, net of tax	(15)			(15)
Ending balance at Mar. 31, 2020	14,074	$ 19	513,223	(18)	(499,150)
Ending balance, shares at Mar. 31, 2020		195,834,000
Beginning balance at Dec. 31, 2019	22,860	$ 19	512,046	(3)	(489,202)
Beginning balance, shares at Dec. 31, 2019		195,257,000
Net income (loss)	4,390
Ending balance at Jun. 30, 2020	36,342	$ 19	521,064	71	(484,812)
Ending balance, shares at Jun. 30, 2020		199,563,000
Stock-based compensation expense from stock options and ESPP shares, shares		577,000
Beginning balance at Mar. 31, 2020	14,074	$ 19	513,223	(18)	(499,150)
Beginning balance, shares at Mar. 31, 2020		195,834,000
Issuance of common stock upon equity financings, net of issuance costs	6,202		6,202
Issuance of common stock upon equity financings, net of issuance cost, shares		2,610,000
Issuance of common stock upon ESPP purchases	1,145		1,145
Issuance of common stock upon ESPP purchases, shares		1,119,000
Stock-based compensation expense from stock options and ESPP shares	494		494
Net income (loss)	14,338				14,338
Unrealized gain (loss) on available-for-sale securities, net of tax	89			89
Ending balance at Jun. 30, 2020	36,342	$ 19	521,064	71	(484,812)
Ending balance, shares at Jun. 30, 2020		199,563,000
Beginning balance at Dec. 31, 2020	40,115	$ 20	529,884	(5)	(489,784)
Beginning balance, shares at Dec. 31, 2020		203,533,000
Issuance of common stock upon exercise of stock options	3,263	$ 1	3,262
Issuance of common stock upon exercise of stock options, Shares		2,502,000
Issuance of common stock upon equity financings, net of issuance costs	47,786	$ 2	47,784
Issuance of common stock upon equity financings, net of issuance cost, shares		21,315,000
Stock-based compensation expense from stock options and ESPP shares	702		702
Net income (loss)	(10,134)				(10,134)
Unrealized gain (loss) on available-for-sale securities, net of tax	(9)			(9)
Ending balance at Mar. 31, 2021	81,723	$ 23	581,632	(14)	(499,918)
Ending balance, shares at Mar. 31, 2021		227,350,000
Beginning balance at Dec. 31, 2020	40,115	$ 20	529,884	(5)	(489,784)
Beginning balance, shares at Dec. 31, 2020		203,533,000
Net income (loss)	(19,280)
Ending balance at Jun. 30, 2021	73,463	$ 23	582,505	(1)	(509,064)
Ending balance, shares at Jun. 30, 2021		227,496,000
Beginning balance at Mar. 31, 2021	81,723	$ 23	581,632	(14)	(499,918)
Beginning balance, shares at Mar. 31, 2021		227,350,000
Issuance of common stock upon exercise of stock options, ESPP purchases and other	163		163
Issuance of common stock upon exercise of stock options, ESPP purchases and other, shares		146,000
Stock-based compensation expense from stock options and ESPP shares	710		710
Net income (loss)	(9,146)				(9,146)
Unrealized gain (loss) on available-for-sale securities, net of tax	13			13
Ending balance at Jun. 30, 2021	$ 73,463	$ 23	$ 582,505	$ (1)	$ (509,064)
Ending balance, shares at Jun. 30, 2021		227,496,000

Condensed Statements of Stock_2

Condensed Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Jun. 30, 2020
Statement Of Stockholders Equity [Abstract]
Stock issuance costs	$ 269	$ 192

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net (loss) income		$ (19,280)	$ 4,390
Adjustments to reconcile net (loss) income to net cash used in by operating activities:
Depreciation and amortization		60	139
Stock-based compensation		1,412	906
Amortization of debt issuance cost		209	225
Net amortization on investments		(77)	(76)
Changes in operating lease liabilities		(5)	34
Changes in assets and liabilities:
Accounts receivable		124	316
Inventories		(55)	(74)
Prepaid expenses and other assets		353	(1,198)
Accounts payable		(592)	(94)
Accrued and other liabilities		(642)	(2,448)
Contract research liabilities		(353)	(1,081)
Deferred revenue		5	(22,679)
Total adjustments		439	(26,030)
Net cash used in operating activities		(18,841)	(21,640)
Cash flows from investing activities
Purchases of property and equipment		(20)	(146)
Purchases of available-for-sale securities		(42,323)	(28,156)
Proceeds from maturities of available-for-sale securities		30,468	25,357
Net proceeds from sale of LACTEL product line		14,979
Net cash provided by (used in) investing activities		3,104	(2,945)
Cash flows from financing activities
Payments on equipment financing obligations		(1)	(1)
Payment for long-term debt amendment fee		(713)
Net proceeds from issuances of common stock		51,212	8,108
Net cash provided by financing activities		50,498	8,107
Net increase (decrease) in cash, cash equivalents, and restricted cash		34,761	(16,478)
Cash, cash equivalents, and restricted cash, beginning of the period	[1]	21,462	35,074
Cash, cash equivalents, and restricted cash, end of the period	[1]	$ 56,223	$ 18,596
[1]	Includes restricted cash of $150,000 (in long term restricted investments) included in the condensed balance sheets at June 30, 2021 and December 31, 2020.

Condensed Statement of Cash Flo

Condensed Statement of Cash Flows (Parenthetical) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Long Term Restricted Investments [Member]
Restricted cash	$ 150,000	$ 150,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1. Summary of Significant Accounting Policies Nature of Operations DURECT Corporation (the Company) was incorporated in the state of Delaware on February 6, 1998. The Company is a biopharmaceutical company with research and development programs broadly falling into two categories: (i) new chemical entities derived from our Epigenetics Regulator Program, in which the Company attempts to discover and develop molecules which have not previously been approved and marketed as therapeutics, and (ii) Proprietary Pharmaceutical Programs, in which the Company applies its formulation expertise and technologies largely to active pharmaceutical ingredients whose safety and efficacy have previously been established but which the Company aims to improve in some manner through a new formulation. The Company has several product candidates under development by itself and with third party collaborators. The Company also manufactures and sells osmotic pumps used in laboratory research, and manufactures certain excipients for certain clients for use as raw materials in their products. In addition, the Company conducts research and development of pharmaceutical products in collaboration with third party pharmaceutical and biotechnology companies. Basis of Presentation These financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (SEC), and therefore do not include all the information and footnotes necessary for a complete presentation of the Company’s results of operations, financial position and cash flows in conformity with U.S. generally accepted accounting principles (U.S. GAAP). The unaudited financial statements reflect all adjustments (consisting only of normal recurring adjustments) which are, in the opinion of management, necessary for a fair presentation of the financial position at June 30, 2021, the operating results and comprehensive (loss) income, and stockholders’ equity for the three and six months ended June 30, 2021 and 2020, and cash flows for the six months ended June 30, 2021 and 2020. The balance sheet as of December 31, 2020 has been derived from audited financial statements at that date but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These financial statements and notes should be read in conjunction with the Company’s audited financial statements and notes thereto, included in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2020 filed with the SEC. The results of operations for the interim periods presented are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year. Discontinued Operations In December 2020, the Company announced its decision to sell its LACTEL Absorbable Polymer (LACTEL) product line to Evonik, which was completed on December 31, 2020 and therefore the accompanying statement of operations for the three and six months ended June 30, 2020 has been recast to reflect the revenue and expenses related to the Company’s LACTEL product line as discontinued operations (see Note 8). The Company believes this format provides comparability with its previously filed financial statements. Risks and Uncertainties The pandemic caused by an outbreak of a new strain of coronavirus, COVID-19, has resulted, and is likely to continue to result, in significant national and global economic disruption and may adversely affect our business. COVID-19 initially also had a negative impact on orders for our ALZET product line as many ALZET customers reduced their activities during the pandemic. ALZET orders have recovered significantly in 2021, a trend that may or may Liquidity and Need to Raise Additional Capital As of June 30, 2021, the Company had an accumulated deficit of $509.1 million as well as negative cash flows from operating activities for the six months ended June 30, 2021, condensed financial statements are filed, may include seeking additional collaborative agreements for certain of the Company’s programs and achieving revenue from its collaboration and licensing agreements , as well as financing activities such as public offerings and private placements of its common stock, preferred stock offerings, issuances of debt and convertible debt instruments . There are no assurances that such additional funding will be obtained or that the Company will succeed in its future operations. If the Company cannot successfully raise additional capital when needed and implement its strategic development plan, its liquidity, financial condition and business prospects will be materially and adversely affected. Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. The Company capitalizes inventories produced in preparation for product launches after receiving regulatory approval on the product. The Company may be required to expense previously capitalized inventory costs upon a change in management’s judgment due to new information that suggests that the inventory will not be saleable. If the Company is able to subsequently sell products made with raw materials that were previously written down, the Company will report an unusually high gross profit as there will be no associated cost of goods for these materials. The Company’s inventories consist of the following (in thousands): June 30, 2021 December 31, 2020 (unaudited) Raw materials $ 268 $ 136 Work in process 623 796 Finished goods 1,027 932 Total inventories $ 1,918 $ 1,864 Revenue Recognition The Company enters into license and collaboration agreements under which the Company may receive upfront license fees, research funding and contingent milestone payments and royalties. Product Revenue, Net The Company sells osmotic pumps used in laboratory research, and manufactures certain excipients for pharmaceutical clients for use as raw materials in their products. Revenues from product sales are recognized when the customer obtains control of the Company’s product, which occurs at a point in time, typically upon shipment to the customer. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less. Trade Discounts and Allowances: The Company provides certain customers with discounts that are explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized. Product Returns: Consistent with industry practice, the Company generally offers customers a limited right of return for products that have been purchased from the Company. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using its historical sales information. Consistent with historical experience, the Company continues to expect product returns to be minimal. Collaborative Research and Development and Other Revenue The Company enters into license agreements, under which it licenses certain rights to its product candidates to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees; reimbursement of development costs incurred by the Company under approved work plans; development, regulatory and commercial milestone payments; payments for manufacturing supply services the Company provides through its contract manufacturers; and royalties on net sales of licensed products. Each of these payments results in collaborative research and development revenues, except for revenues from royalties on net sales of licensed products, which are classified as other revenues. In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the standalone selling price, which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. The Company expects to recognize revenue for the variable consideration currently being constrained when it is probable that a significant revenue reversal will not occur. Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaborative research and development revenues and net income (loss) in the period of adjustment. Milestone Payments: At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaborative research and development revenues and net income (loss) in the period of adjustment. Manufacturing Supply Services: Arrangements that include a promise for future supply of drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide a material right to the customer and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded in collaborative research and development revenue when the customer obtains control of the goods, which is upon delivery. Royalties and Earn-outs: For arrangements that include sales-based royalties or earn-outs, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized material royalty revenue resulting from the Company’s collaborative arrangements or material earn-out revenue from the Company’s patent purchase agreement with Indivior. The Company receives payments from its customers based on development cost schedules established in each contract. Up-front payments are recorded as deferred revenue upon receipt or when due, and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. Total revenue by geographic region (based on the location of the customer) for the three and six months ended June 30, 2021 and 2020 are as follows (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 United States $ 1,684 $ 23,900 $ 2,932 $ 24,741 Japan 165 228 645 502 Europe 282 256 583 566 Other 172 114 355 284 Total $ 2,303 $ 24,498 $ 4,515 $ 26,093 Prepaid and Accrued Contract Research Expenses The Company incurs significant costs associated with third party consultants and organizations for pre-clinical studies, clinical trials, contract research and manufacturing, validation, testing, regulatory advice and other research and development-related services. The Company is required to estimate periodically the cost of services rendered but unbilled based on management’s estimates of project status. If these good faith estimates are inaccurate, actual expenses incurred could materially differ from these estimates. Research and development expenses are primarily comprised of salaries and benefits associated with research and development personnel, overhead and facility costs, preclinical and non-clinical development costs, clinical trial and related clinical manufacturing costs, contract services, and other outside costs. Research and development costs are expensed as incurred. Research and development costs paid to third parties under sponsored research agreements are recognized as the related services are performed. In addition, reimbursements of research and development expenses incurred by the Company’s partners are recorded as collaborative research and development revenue . Comprehensive (Loss) income Components of other comprehensive loss are comprised entirely of unrealized gains and losses on the Company’s available-for-sale securities for all periods presented. Total comprehensive loss has been disclosed in the Company’s Statements of Comprehensive Loss. Net (Loss) income Per Share Basic net (loss) income per share is calculated by dividing the net (loss) income by the weighted-average number of common shares outstanding. Diluted net (loss) income per share is computed using the weighted-average number of common shares outstanding and common stock equivalents (i.e., options to purchase common stock) outstanding during the period, if dilutive, using the treasury stock method for options. The numerators and denominators in the calculation of basic and diluted net (loss) income per share were as follows (in thousands except per share amounts): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Numerators: Net (loss) income $ (9,146 ) $ 14,338 $ (19,280 ) $ 4,390 Denominator: Weighted average shares used to compute basic net (loss) income per share 227,428 196,866 222,510 196,306 Dilutive common shares from stock options and ESPP — 10,611 — 9,805 Weighted average shares used to compute diluted net (loss) income per share 227,428 207,477 222,510 206,111 Net (loss) income per share: Basic $ (0.04 ) $ 0.07 $ (0.09 ) $ 0.02 Diluted $ (0.04 ) $ 0.07 $ (0.09 ) $ 0.02 Options to purchase approximately 8.1 million and 7.9 million shares of common stock were excluded from the denominator in the calculation of diluted net loss per share for the three and six months ended June 30, 2021, respectively, as the effect would be antidilutive. Options to purchase approximately 4.4 million and 7.2 million shares of common stock were excluded from the denominator in the calculation of diluted net income per share for the three and six months ended June 30, 2020, respectively, as the effect would be anti-dilutive. Recent Accounting Pronouncements In June 2016, the FASB issued Accounting Standards Update No. 2016-13 (ASU 2016-13) “Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires measurement and recognition of expected credit losses for financial assets. This standard is effective for fiscal years beginning after December 15, 2022 for small reporting companies, including interim reporting periods within those years and must be adopted using a modified retrospective approach, with certain exceptions. Early adoption is permitted. The Company does not expect the adoption of this standard to have a material effect on its financial statements.

Strategic Agreements

Strategic Agreements	6 Months Ended
	Jun. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Strategic Agreements	Note 2. Strategic Agreements The collaborative research and development and other revenues associated with the Company’s collaborators or counterparties are as follows (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Collaborator/Counterparty Gilead (1) $ — $ 23,144 $ — $ 22,876 Others (2) 735 203 1,309 441 Total collaborative research and development and other revenue $ 735 $ 23,347 $ 1,309 $ 23,317 (1) Amounts related to recognition of a license upfront fee and milestone payment were zero for both the three and six months ended June 30, 2021 compared to $23.1 million and $22.7 million for the corresponding periods in 2020, respectively. The Company signed a license agreement with Gilead on July 19, 2019 and received a nonrefundable upfront license fee and a milestone payment totaling $35.0 million in 2019 which was being recognized as revenue as the Company’s obligation was being satisfied. In June 2020, the Company received notice that Gilead was terminating the License Agreement and a related R&D agreement and as a result, the Company recognized all its remaining deferred revenue as there were no remaining substantive performance obligations to be provided to Gilead by the Company as of the date when the termination notice was received. (2) Includes: (a) amounts related to earn-out revenue from Indivior UK Limited (Indivior) with respect to PERSERIS net sales; (b) feasibility programs; (c) research and development activities funded by Santen Pharmaceutical Co. Ltd. (Santen); and (d) royalty revenue from OP Pharma with respect to Methydur net sales. Note that in January 2018, the Company was notified by Santen that due to a shift in priorities, Santen had elected to reallocate research and development resources and put the Company’s program on pause until further notice. While the main program is on pause, the parties are working together on a limited set of research and development activities funded by Santen. Patent Purchase Agreement with Indivior On September 26, 2017, the Company entered into a Patent Purchase Agreement (the “Indivior Agreement”) with Indivior. Pursuant to the Indivior Agreement, the Company assigned to Indivior certain patent rights including granted patents extending through at least 2026. The Indivior Agreement contains customary representations, warranties and indemnities of the parties. Amounts recognized in the three and six months ended June 30, 2021 and 2020 related to earn-out revenues from PERSERIS have been immaterial and are included in collaborative research and development and other revenue. Agreement with Santen Pharmaceutical Co., Ltd. On December 11, 2014, the Company and Santen Pharmaceutical Co., Ltd. (Santen) entered into a definitive agreement (the Santen Agreement). Pursuant to the Santen Agreement, the Company granted Santen an exclusive worldwide license to the Company’s proprietary SABER formulation platform and other intellectual property to develop and commercialize a sustained release product utilizing the Company’s SABER technology to deliver an ophthalmology drug. Santen controls and funds the development and commercialization program, and the parties established a joint management committee to oversee, review and coordinate the development activities of the parties under the Santen Agreement. In connection with the Santen agreement, Santen agreed to pay the Company an upfront fee of $2.0 million in cash and to make contingent cash payments to the Company of up to $76.0 million upon the achievement of certain milestones, of which $13.0 million are development-based milestones and $63.0 million are commercialization-based milestones including milestones requiring the achievement of certain product sales targets (none of which has been achieved as of June 30, 2021). Santen will also pay for certain Company costs incurred in the development of the licensed product. If the product is commercialized, the Company would also receive a tiered royalty on annual net product sales ranging from single-digit to the low double digits, determined on a country-by-country basis. In January 2018, the Company was notified by Santen that due to a shift in near term priorities, Santen elected to reallocate research and development resources and put the Company’s program on pause until further notice . While the main program is on pause, the parties are working together on a limited set of research and development activities funded by Santen. As of June 30 , 2021 , the cumulative aggregate payments received by the Company under this agreement were $ 3.3 million.

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Financial Instruments	Note 3. Financial Instruments Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company’s valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. The Company follows a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value. These levels of inputs are the following: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company’s financial instruments are valued using quoted prices in active markets or based upon other observable inputs. Money market funds are classified as Level 1 financial assets. Certificates of deposit, commercial paper, municipal bonds, corporate debt securities, and U.S. Government agency securities are classified as Level 2 financial assets. The fair value of the Level 2 assets is estimated using pricing models using current observable market information for similar securities. The Company’s Level 2 investments include U.S. government-backed securities and corporate securities that are valued based upon observable inputs that may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data including market research publications. The fair value of commercial paper is based upon the time to maturity and discounted using the three-month treasury bill rate. The average remaining maturity of the Company’s Level 2 investments as of June 30, 2021 is less than twelve months and these investments are rated by S&P and Moody’s at AAA or AA- for securities and A1, A2, P1 or P2 for commercial paper. The following is a summary of available-for-sale securities as of June 30, 2021 and December 31, 2020 (in thousands): June 30, 2021 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 23,886 $ — $ — $ 23,886 Certificates of deposit 150 — — 150 Commercial paper 56,668 4 (4 ) 56,668 Municipal bonds 1,972 — (1 ) 1,971 Corporate debt 1,309 — — 1,309 $ 83,985 $ 4 $ (5 ) $ 83,984 Reported as: Cash and cash equivalents $ 51,479 $ — $ (2 ) $ 51,477 Short-term investments 32,356 4 (3 ) 32,357 Long-term restricted investments 150 — — 150 $ 83,985 $ 4 $ (5 ) $ 83,984 December 31, 2020 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 522 $ — $ — $ 522 Certificates of deposit 150 — — 150 Commercial paper 32,213 2 (2 ) 32,213 Municipal bonds 6,310 — (5 ) 6,305 U.S. Government agencies 1,000 — — 1,000 $ 40,195 $ 2 $ (7 ) $ 40,190 Reported as: Cash and cash equivalents $ 19,619 $ 1 $ (1 ) $ 19,619 Short-term investments 19,426 1 (6 ) 19,421 Long-term investments 1,000 — — 1,000 Long-term restricted investments 150 — — 150 $ 40,195 $ 2 $ (7 ) $ 40,190 The following is a summary of the cost and estimated fair value of available-for-sale securities at June 30, 2021, by contractual maturity (in thousands): June 30, 2021 Amortized Cost Estimated Fair Value Mature in one year or less $ 59,949 $ 59,948 Mature after one year through five years 150 150 $ 60,099 $ 60,098 There were no securities that have had an unrealized loss for more than 12 months as of June 30, 2021. As of June 30, 2021, unrealized losses on available-for-sale investments are not attributed to credit risk and are considered to be temporary. The Company believes that it is more-likely-than-not that investments in an unrealized loss position will be held until maturity or the recovery of the cost basis of the investment. To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	Note 4. Stock-Based Compensation As of June 30, 2021, the Company has two stock-based compensation plans. The stock-based compensation cost that has been included in the statements of comprehensive (loss) income is shown as below (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Cost of product revenues $ 6 $ 3 $ 11 $ 5 Research and development 320 245 635 452 Selling, general and administrative 384 216 766 394 Total stock-based compensation $ 710 $ 464 $ 1,412 $ 851 As of June 30, 2021 and 2020, $16,000 and $15,000 of stock-based compensation cost was capitalized in inventory on the Company’s balance sheets, respectively. The Company uses the Black-Scholes option pricing model to value its stock options. The expected life computation is based on historical exercise patterns and post-vesting termination behavior. The Company considered its historical volatility in developing its estimate of expected volatility. The Company used the following assumptions to estimate the fair value of stock options granted and shares purchased under its employee stock purchase plan for the three and six months ended June 30, 2021 and 2020: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Stock Options Risk-free rate 1.2-1.3% 0.5% 0.8-1.3% 0.5-1.4% Expected dividend yield — — — — Expected life of option (in years) 7.0 7.0-7.3 7.0-7.3 7.0-7.3 Volatility 86% 86-87% 74-86% 84-87% Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Employee Stock Purchase Plan Risk-free rate 0.04% 0.1% 0.04-0.1% 0.1-1.6% Expected dividend yield — — — — Expected life of option (in years) 0.5 0.5 0.5 0.5 Volatility 71-78% 105-124% 71-78% 105-124%

Term Loan

Term Loan	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Term Loan	Note 5. Term Loan In July 2016, the Company entered into a $20.0 million secured single-draw term loan with Oxford Finance LLC (Oxford Finance). The Company and Oxford Finance entered into five subsequent amendments to the Loan Agreement in February 2018, November 2018, December 2019, March 2021 and May 2021. For amendments 1-3 and 5, the Company paid Oxford Finance loan modification fees of $100,000, $900,000, $825,000 and $712,500 respectively. As amended, the Loan Agreement provides for interest only payments through June 1, 2023, followed by consecutive monthly payments of principal and interest in arrears starting on June 1, 2023 and continuing through the maturity date of the term loan of September 1, 2025. The Loan Agreement provides for a floating interest rate (7.95% initially and 7.95% as of June 30, 2021) based on an index rate plus a spread. In addition, a payment equal to 10% of the principal amount of the term loan is due when the term loan becomes due or upon the prepayment of the facility. If the Company elects to prepay the loan, there is also a prepayment fee of between 0.75% and 2.5% of the principal amount of the term loan depending on the timing of prepayment. The $150,000 facility fee that was paid at the original closing, the loan modification fees and other debt offering/issuance costs have been recorded as debt discount on the Company’s balance sheet and together with the final $2.0 million payment are being amortized to interest expense using the effective interest method over the revised term of the loan. The term loan is secured by substantially all of the assets of the Company, except that the collateral does not include any intellectual property (including licensing, collaboration and similar agreements relating thereto), and certain other excluded assets. The 2016 Loan Agreement contains customary representations, warranties and covenants by the Company, which covenants limit the Company’s ability to convey, sell, lease, transfer, assign or otherwise dispose of certain assets of the Company; engage in any business other than the businesses currently engaged in by the Company or reasonably related thereto; liquidate or dissolve; make certain management changes; undergo certain change of control events; create, incur, assume, or be liable with respect to certain indebtedness; grant certain liens; pay dividends and make certain other restricted payments; make certain investments; and make payments on any subordinated debt. The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, the Company’s failure to fulfill certain obligations of the Company under the Loan Agreement and the occurrence of a material adverse change which is defined as a material adverse change in the Company’s business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of lender’s lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the lender would be entitled to exercise its remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement, which could harm the Company’s financial condition. The conditionally exercisable call option related to the event of default is considered to be an embedded derivative which is required to be bifurcated and accounted for as a separate financial instrument. In the periods presented, the value of the embedded derivative is not material, but could become material in future periods if an event of default became more probable than is currently estimated. The fair value of the term loan approximates the carrying value. Future maturities and interest payments due under the term loan as of June 30, 2021, are as follows (in thousands): Six months ended December 31, 2021 $ 813 2022 1,612 2023 7,191 2024 9,408 2025 7,885 Total minimum payments 26,909 Less amount representing interest (5,088 ) Gross balance of term loan 21,821 Less unamortized debt discount (1,461 ) Carrying value of term loan, net 20,360 Less term loan, current portion, net — Term loan, non-current portion, net $ 20,360 As of June 30, 2021, the Company was in compliance with all material covenants under the Loan Agreement and there had been no material adverse change.

Commitments

Commitments	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments	Note 6. Commitments Operating Leases The Company has lease arrangements for its facilities as follows. Location Approximate Square Feet Operation Expiration Cupertino, CA 30,149 sq. ft. Office, Laboratory and Manufacturing Lease expires 2024 (with an option to renew for an additional five years) Cupertino, CA 20,100 sq. ft. Office and Laboratory Lease expires 2024 (with an option to renew for an additional five years) Vacaville, CA 24,634 sq. ft. Manufacturing Lease expires 2023 Under these leases, the Company is required to pay certain maintenance expenses in addition to monthly rent. Rent expense is recognized on a straight-line basis over the lease term for leases that have scheduled rental payment increases. The lease expense includes the amortization of the right-of-assets with the associated interest component estimated by applying the effective interest method. Rent expense under all operating leases was $478,000 and $957,000 for the three and six months ended June 30, 2021, respectively, compared to $483,000 and $968,000 for the corresponding periods in 2020. Future minimum payments under these noncancelable leases are as follows (in thousands): Operating Leases Six months ended December 31, 2021 $ 946 2022 1,991 2023 1,970 2024 275 $ 5,182

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Equity	Note 7. Stockholders’ Equity In August 2018, the Company filed a shelf registration statement on Form S-3 with the SEC (the “2018 Registration Statement”) (File No. 333-226518), which upon being declared effective in October 2018, terminated the Company’s registration statement filed in November 2015 (File No. 333-207776) and allowed the Company to offer up to $175.0 million of securities from time to time in one or more public offerings, inclusive of up to $75.0 million of shares of the Company’s common stock which the Company may sell, subject to certain limitations, pursuant to a sales agreement dated November 3, 2015 with Cantor Fitzgerald & Co. (the “2015 Sales Agreement”). In February 2021, the Company completed an underwritten public offering of 20,364,582 shares of its common stock at a price of $2.2386 per share pursuant to an underwriting agreement with Cantor Fitzgerald & Co., raising total gross proceeds to the Company of approximately $45.6 million before deducting estimated offering expenses payable by the Company. Total stock issuance costs related to this financing were approximately $195,000. After deducting estimated offering expenses payable by the Company, the net proceeds to the Company were approximately $45.4 million. During the three months ended June 30, 2021, the Company did not issue any shares pursuant to the 2018 Registration Statement and the 2015 Sales Agreement. During the six months ended June 30, 2021, the Company raised net proceeds (net of commissions) of approximately $2.4 million from the sale of 950,009 shares of the Company’s common stock in the open market at a weighted average price of $2.60 per share pursuant to the 2018 Registration Statement and the 2015 Sales Agreement. During the three and six months ended June 30, 2020, the Company raised net proceeds (net of commissions) of approximately $6.2 million from the sale of 2,610,375 shares of the Company’s common stock in the open market at a weighted average price of $2.45 per share, pursuant to the 2018 Registration Statement and the 2015 Sales Agreement.

Discontinued Operations

Discontinued Operations	6 Months Ended
	Jun. 30, 2021
Disposal Group Not Discontinued Operation Income Statement Disclosures [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure	Note 8. On December 31, 2020, the Company completed the sale of its LACTEL Absorbable Polymers product line to Evonik. Under the terms of the Asset Purchase Agreement, Evonik paid DURECT approximately $15 million subjects to certain adjustments, and also agreed to assume certain liabilities with respect to the transferred assets. As a result of the sale of the LACTEL product line, the operating results from the Company’s LACTEL product line have been excluded from continuing operations and presented as discontinued operations in the accompanying Statement of Operations and Comprehensive (Loss) Income for the three and six months ended June 30, 2020. During the twelve months ended December 31, 2020, the Company recorded a gain on sale of the LACTEL product line of $12.8 million, upon the completion of sale to Evonik. The results of operations below include certain allocations that management believes fairly reflect the utilization of services provided to the LACTEL product line. The allocations do not include amounts related to general corporate administrative expenses or interest expense. Therefore, these results of operations do not necessarily reflect what the results of operations would have been had the LACTEL product line operated as a stand-alone entity. The components of income from discontinued operations as reported in the Company’s statement of operations were as follows (in thousands): Three months ended June 30, Six months ended June 30, 2020 2020 Product revenue, net $ 1,346 $ 2,526 Total revenues 1,346 2,526 Operating expenses: Cost of product revenues 711 1,547 Research and development 118 248 Selling, general and administrative 103 112 Total costs and expenses 932 1,907 Net income from discontinued operations $ 414 $ 619 Net income per share Basic and diluted $ 0.00 $ 0.00 Weighted-average shares used in computing net income per share Basic 196,866 196,306 Diluted 207,477 206,111 The following table presents certain non-cash items related to discontinued operations, which are included in the Company’s statement of cash flows (in thousands): Three months ended June 30, Six months ended June 30, 2020 2020 Depreciation $ 49 $ 99 Stock-based compensation expense 28 55 Non-cash items, net $ 77 $ 154

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations DURECT Corporation (the Company) was incorporated in the state of Delaware on February 6, 1998. The Company is a biopharmaceutical company with research and development programs broadly falling into two categories: (i) new chemical entities derived from our Epigenetics Regulator Program, in which the Company attempts to discover and develop molecules which have not previously been approved and marketed as therapeutics, and (ii) Proprietary Pharmaceutical Programs, in which the Company applies its formulation expertise and technologies largely to active pharmaceutical ingredients whose safety and efficacy have previously been established but which the Company aims to improve in some manner through a new formulation. The Company has several product candidates under development by itself and with third party collaborators. The Company also manufactures and sells osmotic pumps used in laboratory research, and manufactures certain excipients for certain clients for use as raw materials in their products. In addition, the Company conducts research and development of pharmaceutical products in collaboration with third party pharmaceutical and biotechnology companies.
Basis of Presentation	Basis of Presentation These financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (SEC), and therefore do not include all the information and footnotes necessary for a complete presentation of the Company’s results of operations, financial position and cash flows in conformity with U.S. generally accepted accounting principles (U.S. GAAP). The unaudited financial statements reflect all adjustments (consisting only of normal recurring adjustments) which are, in the opinion of management, necessary for a fair presentation of the financial position at June 30, 2021, the operating results and comprehensive (loss) income, and stockholders’ equity for the three and six months ended June 30, 2021 and 2020, and cash flows for the six months ended June 30, 2021 and 2020. The balance sheet as of December 31, 2020 has been derived from audited financial statements at that date but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These financial statements and notes should be read in conjunction with the Company’s audited financial statements and notes thereto, included in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2020 filed with the SEC. The results of operations for the interim periods presented are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year.
Discontinued Operations	Discontinued Operations In December 2020, the Company announced its decision to sell its LACTEL Absorbable Polymer (LACTEL) product line to Evonik, which was completed on December 31, 2020 and therefore the accompanying statement of operations for the three and six months ended June 30, 2020 has been recast to reflect the revenue and expenses related to the Company’s LACTEL product line as discontinued operations (see Note 8). The Company believes this format provides comparability with its previously filed financial statements.
Risks And Uncertainties	Risks and Uncertainties The pandemic caused by an outbreak of a new strain of coronavirus, COVID-19, has resulted, and is likely to continue to result, in significant national and global economic disruption and may adversely affect our business. COVID-19 initially also had a negative impact on orders for our ALZET product line as many ALZET customers reduced their activities during the pandemic. ALZET orders have recovered significantly in 2021, a trend that may or may
Liquidity and Need to Raise Additional Capital	Liquidity and Need to Raise Additional Capital As of June 30, 2021, the Company had an accumulated deficit of $509.1 million as well as negative cash flows from operating activities for the six months ended June 30, 2021, condensed financial statements are filed, may include seeking additional collaborative agreements for certain of the Company’s programs and achieving revenue from its collaboration and licensing agreements , as well as financing activities such as public offerings and private placements of its common stock, preferred stock offerings, issuances of debt and convertible debt instruments . There are no assurances that such additional funding will be obtained or that the Company will succeed in its future operations. If the Company cannot successfully raise additional capital when needed and implement its strategic development plan, its liquidity, financial condition and business prospects will be materially and adversely affected.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. The Company capitalizes inventories produced in preparation for product launches after receiving regulatory approval on the product. The Company may be required to expense previously capitalized inventory costs upon a change in management’s judgment due to new information that suggests that the inventory will not be saleable. If the Company is able to subsequently sell products made with raw materials that were previously written down, the Company will report an unusually high gross profit as there will be no associated cost of goods for these materials. The Company’s inventories consist of the following (in thousands): June 30, 2021 December 31, 2020 (unaudited) Raw materials $ 268 $ 136 Work in process 623 796 Finished goods 1,027 932 Total inventories $ 1,918 $ 1,864
Revenue Recognition	Revenue Recognition The Company enters into license and collaboration agreements under which the Company may receive upfront license fees, research funding and contingent milestone payments and royalties. Product Revenue, Net The Company sells osmotic pumps used in laboratory research, and manufactures certain excipients for pharmaceutical clients for use as raw materials in their products. Revenues from product sales are recognized when the customer obtains control of the Company’s product, which occurs at a point in time, typically upon shipment to the customer. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less. Trade Discounts and Allowances: The Company provides certain customers with discounts that are explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized. Product Returns: Consistent with industry practice, the Company generally offers customers a limited right of return for products that have been purchased from the Company. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using its historical sales information. Consistent with historical experience, the Company continues to expect product returns to be minimal. Collaborative Research and Development and Other Revenue The Company enters into license agreements, under which it licenses certain rights to its product candidates to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees; reimbursement of development costs incurred by the Company under approved work plans; development, regulatory and commercial milestone payments; payments for manufacturing supply services the Company provides through its contract manufacturers; and royalties on net sales of licensed products. Each of these payments results in collaborative research and development revenues, except for revenues from royalties on net sales of licensed products, which are classified as other revenues. In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the standalone selling price, which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. The Company expects to recognize revenue for the variable consideration currently being constrained when it is probable that a significant revenue reversal will not occur. Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaborative research and development revenues and net income (loss) in the period of adjustment. Milestone Payments: At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaborative research and development revenues and net income (loss) in the period of adjustment. Manufacturing Supply Services: Arrangements that include a promise for future supply of drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide a material right to the customer and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded in collaborative research and development revenue when the customer obtains control of the goods, which is upon delivery. Royalties and Earn-outs: For arrangements that include sales-based royalties or earn-outs, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized material royalty revenue resulting from the Company’s collaborative arrangements or material earn-out revenue from the Company’s patent purchase agreement with Indivior. The Company receives payments from its customers based on development cost schedules established in each contract. Up-front payments are recorded as deferred revenue upon receipt or when due, and may require deferral of revenue recognition to a future period until the Company performs its obligations under these arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. Total revenue by geographic region (based on the location of the customer) for the three and six months ended June 30, 2021 and 2020 are as follows (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 United States $ 1,684 $ 23,900 $ 2,932 $ 24,741 Japan 165 228 645 502 Europe 282 256 583 566 Other 172 114 355 284 Total $ 2,303 $ 24,498 $ 4,515 $ 26,093
Prepaid and Accrued Contract Research Expenses	Prepaid and Accrued Contract Research Expenses The Company incurs significant costs associated with third party consultants and organizations for pre-clinical studies, clinical trials, contract research and manufacturing, validation, testing, regulatory advice and other research and development-related services. The Company is required to estimate periodically the cost of services rendered but unbilled based on management’s estimates of project status. If these good faith estimates are inaccurate, actual expenses incurred could materially differ from these estimates. Research and development expenses are primarily comprised of salaries and benefits associated with research and development personnel, overhead and facility costs, preclinical and non-clinical development costs, clinical trial and related clinical manufacturing costs, contract services, and other outside costs. Research and development costs are expensed as incurred. Research and development costs paid to third parties under sponsored research agreements are recognized as the related services are performed. In addition, reimbursements of research and development expenses incurred by the Company’s partners are recorded as collaborative research and development revenue .
Comprehensive (Loss) Income	Comprehensive (Loss) income Components of other comprehensive loss are comprised entirely of unrealized gains and losses on the Company’s available-for-sale securities for all periods presented. Total comprehensive loss has been disclosed in the Company’s Statements of Comprehensive Loss.
Net (Loss) Income Per Share	Net (Loss) income Per Share Basic net (loss) income per share is calculated by dividing the net (loss) income by the weighted-average number of common shares outstanding. Diluted net (loss) income per share is computed using the weighted-average number of common shares outstanding and common stock equivalents (i.e., options to purchase common stock) outstanding during the period, if dilutive, using the treasury stock method for options. The numerators and denominators in the calculation of basic and diluted net (loss) income per share were as follows (in thousands except per share amounts): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Numerators: Net (loss) income $ (9,146 ) $ 14,338 $ (19,280 ) $ 4,390 Denominator: Weighted average shares used to compute basic net (loss) income per share 227,428 196,866 222,510 196,306 Dilutive common shares from stock options and ESPP — 10,611 — 9,805 Weighted average shares used to compute diluted net (loss) income per share 227,428 207,477 222,510 206,111 Net (loss) income per share: Basic $ (0.04 ) $ 0.07 $ (0.09 ) $ 0.02 Diluted $ (0.04 ) $ 0.07 $ (0.09 ) $ 0.02 Options to purchase approximately 8.1 million and 7.9 million shares of common stock were excluded from the denominator in the calculation of diluted net loss per share for the three and six months ended June 30, 2021, respectively, as the effect would be antidilutive. Options to purchase approximately 4.4 million and 7.2 million shares of common stock were excluded from the denominator in the calculation of diluted net income per share for the three and six months ended June 30, 2020, respectively, as the effect would be anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the FASB issued Accounting Standards Update No. 2016-13 (ASU 2016-13) “Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires measurement and recognition of expected credit losses for financial assets. This standard is effective for fiscal years beginning after December 15, 2022 for small reporting companies, including interim reporting periods within those years and must be adopted using a modified retrospective approach, with certain exceptions. Early adoption is permitted. The Company does not expect the adoption of this standard to have a material effect on its financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Summary of Components of Inventories	The Company’s inventories consist of the following (in thousands): June 30, 2021 December 31, 2020 (unaudited) Raw materials $ 268 $ 136 Work in process 623 796 Finished goods 1,027 932 Total inventories $ 1,918 $ 1,864
Summary of Total Revenue by Geographic Region	Total revenue by geographic region (based on the location of the customer) for the three and six months ended June 30, 2021 and 2020 are as follows (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 United States $ 1,684 $ 23,900 $ 2,932 $ 24,741 Japan 165 228 645 502 Europe 282 256 583 566 Other 172 114 355 284 Total $ 2,303 $ 24,498 $ 4,515 $ 26,093
Summary of Numerators and Denominators in Calculation of Basic and Diluted Net (Loss) Income per Share	The numerators and denominators in the calculation of basic and diluted net (loss) income per share were as follows (in thousands except per share amounts): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Numerators: Net (loss) income $ (9,146 ) $ 14,338 $ (19,280 ) $ 4,390 Denominator: Weighted average shares used to compute basic net (loss) income per share 227,428 196,866 222,510 196,306 Dilutive common shares from stock options and ESPP — 10,611 — 9,805 Weighted average shares used to compute diluted net (loss) income per share 227,428 207,477 222,510 206,111 Net (loss) income per share: Basic $ (0.04 ) $ 0.07 $ (0.09 ) $ 0.02 Diluted $ (0.04 ) $ 0.07 $ (0.09 ) $ 0.02

Strategic Agreements (Tables)

Strategic Agreements (Tables)	6 Months Ended
	Jun. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Collaborative Research and Development and Other Revenues Associated with Company's Collaborators or Counterparties	The collaborative research and development and other revenues associated with the Company’s collaborators or counterparties are as follows (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Collaborator/Counterparty Gilead (1) $ — $ 23,144 $ — $ 22,876 Others (2) 735 203 1,309 441 Total collaborative research and development and other revenue $ 735 $ 23,347 $ 1,309 $ 23,317 (1) Amounts related to recognition of a license upfront fee and milestone payment were zero for both the three and six months ended June 30, 2021 compared to $23.1 million and $22.7 million for the corresponding periods in 2020, respectively. The Company signed a license agreement with Gilead on July 19, 2019 and received a nonrefundable upfront license fee and a milestone payment totaling $35.0 million in 2019 which was being recognized as revenue as the Company’s obligation was being satisfied. In June 2020, the Company received notice that Gilead was terminating the License Agreement and a related R&D agreement and as a result, the Company recognized all its remaining deferred revenue as there were no remaining substantive performance obligations to be provided to Gilead by the Company as of the date when the termination notice was received. (2) Includes: (a) amounts related to earn-out revenue from Indivior UK Limited (Indivior) with respect to PERSERIS net sales; (b) feasibility programs; (c) research and development activities funded by Santen Pharmaceutical Co. Ltd. (Santen); and (d) royalty revenue from OP Pharma with respect to Methydur net sales. Note that in January 2018, the Company was notified by Santen that due to a shift in priorities, Santen had elected to reallocate research and development resources and put the Company’s program on pause until further notice. While the main program is on pause, the parties are working together on a limited set of research and development activities funded by Santen.

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Money Market Funds and Available-for-Sale Securities	The following is a summary of available-for-sale securities as of June 30, 2021 and December 31, 2020 (in thousands): June 30, 2021 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 23,886 $ — $ — $ 23,886 Certificates of deposit 150 — — 150 Commercial paper 56,668 4 (4 ) 56,668 Municipal bonds 1,972 — (1 ) 1,971 Corporate debt 1,309 — — 1,309 $ 83,985 $ 4 $ (5 ) $ 83,984 Reported as: Cash and cash equivalents $ 51,479 $ — $ (2 ) $ 51,477 Short-term investments 32,356 4 (3 ) 32,357 Long-term restricted investments 150 — — 150 $ 83,985 $ 4 $ (5 ) $ 83,984 December 31, 2020 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 522 $ — $ — $ 522 Certificates of deposit 150 — — 150 Commercial paper 32,213 2 (2 ) 32,213 Municipal bonds 6,310 — (5 ) 6,305 U.S. Government agencies 1,000 — — 1,000 $ 40,195 $ 2 $ (7 ) $ 40,190 Reported as: Cash and cash equivalents $ 19,619 $ 1 $ (1 ) $ 19,619 Short-term investments 19,426 1 (6 ) 19,421 Long-term investments 1,000 — — 1,000 Long-term restricted investments 150 — — 150 $ 40,195 $ 2 $ (7 ) $ 40,190
Summary of Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturity	The following is a summary of the cost and estimated fair value of available-for-sale securities at June 30, 2021, by contractual maturity (in thousands): June 30, 2021 Amortized Cost Estimated Fair Value Mature in one year or less $ 59,949 $ 59,948 Mature after one year through five years 150 150 $ 60,099 $ 60,098

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-Based Compensation Cost that has been Included in Statements of Comprehensive (Loss) Income	The stock-based compensation cost that has been included in the statements of comprehensive (loss) income is shown as below (in thousands): Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Cost of product revenues $ 6 $ 3 $ 11 $ 5 Research and development 320 245 635 452 Selling, general and administrative 384 216 766 394 Total stock-based compensation $ 710 $ 464 $ 1,412 $ 851
Summary of Assumptions Used to Estimate Fair Value of Options Granted and Shares Purchased	The Company used the following assumptions to estimate the fair value of stock options granted and shares purchased under its employee stock purchase plan for the three and six months ended June 30, 2021 and 2020: Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Stock Options Risk-free rate 1.2-1.3% 0.5% 0.8-1.3% 0.5-1.4% Expected dividend yield — — — — Expected life of option (in years) 7.0 7.0-7.3 7.0-7.3 7.0-7.3 Volatility 86% 86-87% 74-86% 84-87% Three months ended June 30, Six months ended June 30, 2021 2020 2021 2020 Employee Stock Purchase Plan Risk-free rate 0.04% 0.1% 0.04-0.1% 0.1-1.6% Expected dividend yield — — — — Expected life of option (in years) 0.5 0.5 0.5 0.5 Volatility 71-78% 105-124% 71-78% 105-124%

Term Loan (Tables)

Term Loan (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Schedule of Future Maturities and Interest Payments due under Term Loan	The fair value of the term loan approximates the carrying value. Future maturities and interest payments due under the term loan as of June 30, 2021, are as follows (in thousands): Six months ended December 31, 2021 $ 813 2022 1,612 2023 7,191 2024 9,408 2025 7,885 Total minimum payments 26,909 Less amount representing interest (5,088 ) Gross balance of term loan 21,821 Less unamortized debt discount (1,461 ) Carrying value of term loan, net 20,360 Less term loan, current portion, net — Term loan, non-current portion, net $ 20,360

Commitments (Tables)

Commitments (Tables)	6 Months Ended
	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Summary of Lease Arrangements of Company Facilities	The Company has lease arrangements for its facilities as follows. Location Approximate Square Feet Operation Expiration Cupertino, CA 30,149 sq. ft. Office, Laboratory and Manufacturing Lease expires 2024 (with an option to renew for an additional five years) Cupertino, CA 20,100 sq. ft. Office and Laboratory Lease expires 2024 (with an option to renew for an additional five years) Vacaville, CA 24,634 sq. ft. Manufacturing Lease expires 2023
Schedule of Future Operating Lease Minimum Payments	Future minimum payments under these noncancelable leases are as follows (in thousands): Operating Leases Six months ended December 31, 2021 $ 946 2022 1,991 2023 1,970 2024 275 $ 5,182

Discontinued Operations (Tables

Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2021
Disposal Group Not Discontinued Operation Income Statement Disclosures [Abstract]
Summary of Discontinued Operations Reported in Statement of Operations	The components of income from discontinued operations as reported in the Company’s statement of operations were as follows (in thousands): Three months ended June 30, Six months ended June 30, 2020 2020 Product revenue, net $ 1,346 $ 2,526 Total revenues 1,346 2,526 Operating expenses: Cost of product revenues 711 1,547 Research and development 118 248 Selling, general and administrative 103 112 Total costs and expenses 932 1,907 Net income from discontinued operations $ 414 $ 619 Net income per share Basic and diluted $ 0.00 $ 0.00 Weighted-average shares used in computing net income per share Basic 196,866 196,306 Diluted 207,477 206,111
Summary of Non-cash Items Related to Discontinued Operations Included in Statement of Cash Flows	The following table presents certain non-cash items related to discontinued operations, which are included in the Company’s statement of cash flows (in thousands): Three months ended June 30, Six months ended June 30, 2020 2020 Depreciation $ 49 $ 99 Stock-based compensation expense 28 55 Non-cash items, net $ 77 $ 154

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Date of incorporation			Feb. 6, 1998
Accumulated deficit	$ 509,064		$ 509,064		$ 489,784
Options to purchase common stock excluded from computation of diluted net loss per share	8.1	4.4	7.9	7.2

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Components of Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Inventory Net [Abstract]
Raw materials	$ 268	$ 136
Work in process	623	796
Finished goods	1,027	932
Total inventories	$ 1,918	$ 1,864

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Total Revenue by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 2,303	$ 24,498	$ 4,515	$ 26,093
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,684	23,900	2,932	24,741
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	282	256	583	566
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	165	228	645	502
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 172	$ 114	$ 355	$ 284

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Numerators and Denominators in Calculation of Basic and Diluted Net (Loss) Income per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerators:
Net (loss) income	$ (9,146)	$ (10,134)	$ 14,338	$ (9,948)	$ (19,280)	$ 4,390
Denominator:
Weighted-average shares used in computing net (loss) income per share, basic	227,428		196,866		222,510	196,306
Dilutive common shares from stock options and ESPP	0		10,611		0	9,805
Weighted average shares used to compute diluted net (loss) income per share	227,428		207,477		222,510	206,111
Net (loss) income per share
Basic	$ (0.04)		$ 0.07		$ (0.09)	$ 0.02
Diluted	$ (0.04)		$ 0.07		$ (0.09)	$ 0.02

Strategic Agreements - Summary

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Collaborators or Counterparties (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		$ 2,303	$ 24,498	$ 4,515	$ 26,093
Collaborative Research and Development and Other Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		735	23,347	1,309	23,317
Agreement with Gilead [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		0	23,100	0	22,700
Agreement with Gilead [Member] | Collaborative Research and Development and Other Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	[1]		23,144		22,876
Agreements With Other Collaborators or Counterparties [Member] | Collaborative Research and Development and Other Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	[2]	$ 735	$ 203	$ 1,309	$ 441
[1]	Amounts related to recognition of a license upfront fee and milestone payment were zero for both the three and six months ended June 30, 2021 compared to $23.1 million and $22.7 million for the corresponding periods in 2020, respectively. The Company signed a license agreement with Gilead on July 19, 2019 and received a nonrefundable upfront license fee and a milestone payment totaling $35.0 million in 2019 which was being recognized as revenue as the Company’s obligation was being satisfied.    In June 2020, the Company received notice that Gilead was terminating the License Agreement and a related R&D agreement and as a result, the Company recognized all its remaining deferred revenue as there were no remaining substantive performance obligations to be provided to Gilead by the Company as of the date when the termination notice was received.
[2]	Includes: (a) amounts related to earn-out revenue from Indivior UK Limited (Indivior) with respect to PERSERIS net sales; (b) feasibility programs; (c) research and development activities funded by Santen Pharmaceutical Co. Ltd. (Santen); and (d) royalty revenue from OP Pharma with respect to Methydur net sales. Note that in January 2018, the Company was notified by Santen that due to a shift in priorities, Santen had elected to reallocate research and development resources and put the Company’s program on pause until further notice. While the main program is on pause, the parties are working together on a limited set of research and development activities funded by Santen.

Strategic Agreements - Summar_2

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Collaborators or Counterparties (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 2,303	$ 24,498	$ 4,515	$ 26,093
Agreement with Gilead [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 0	$ 23,100	$ 0	$ 22,700
Agreement with Gilead [Member] | License Fees [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned					$ 35,000

Strategic Agreements - Patent P

Strategic Agreements - Patent Purchase Agreement with Indivior - Additional Information (Detail)	Sep. 26, 2017
Patent Purchase Agreement with Indivior [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Granted patents extending year, minimum	2026

Strategic Agreements - Agreemen

Strategic Agreements - Agreement with Santen Pharmaceutical Co., Ltd. - Additional Information (Detail) - USD ($)	Dec. 11, 2014	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		$ 2,303,000	$ 24,498,000	$ 4,515,000	$ 26,093,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cumulative aggregate payments received by the Company				3,300,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member] | License Fees [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 2,000,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Performance milestone payments based on successful development	76,000,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Development-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Performance milestone payments based on successful development	13,000,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Commercialization-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Performance milestone payments based on successful development	$ 63,000,000
Amount related to the milestone payment earned				$ 0

Financial Instruments - Summary

Financial Instruments - Summary of Money Market Funds and Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 83,985	$ 40,195
Unrealized Gain	4	2
Unrealized Loss	(5)	(7)
Estimated Fair Value	83,984	40,190
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	23,886	522
Estimated Fair Value	23,886	522
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	150	150
Estimated Fair Value	150	150
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	56,668	32,213
Unrealized Gain	4	2
Unrealized Loss	(4)	(2)
Estimated Fair Value	56,668	32,213
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,972	6,310
Unrealized Loss	(1)	(5)
Estimated Fair Value	1,971	6,305
U.S. Government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,000
Estimated Fair Value		1,000
Corporate debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,309
Estimated Fair Value	1,309
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	51,479	19,619
Unrealized Gain		1
Unrealized Loss	(2)	(1)
Estimated Fair Value	51,477	19,619
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,356	19,426
Unrealized Gain	4	1
Unrealized Loss	(3)	(6)
Estimated Fair Value	32,357	19,421
Long Term Restricted Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	150	150
Estimated Fair Value	$ 150	150
Long-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,000
Estimated Fair Value		$ 1,000

Financial Instruments - Summa_2

Financial Instruments - Summary of Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) $ in Thousands	Jun. 30, 2021USD ($)
Investments Debt And Equity Securities [Abstract]
Mature in one year or less, Amortized Cost	$ 59,949
Mature after one year through five years, Amortized Cost	150
Amortized Cost	60,099
Mature in one year or less, Estimated Fair Value	59,948
Mature after one year through five years, Estimated Fair Value	150
Estimated Fair Value	$ 60,098

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail)	Jun. 30, 2021USD ($)
Investments Debt And Equity Securities [Abstract]
Unrealized loss of securities	$ 0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Cost that has been Included in Statements of Comprehensive (Loss) Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 710	$ 464	$ 1,412	$ 851
Cost of product revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	6	3	11	5
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	320	245	635	452
Selling, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 384	$ 216	$ 766	$ 394

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based compensation cost capitalized in inventory	$ 16,000	$ 15,000

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Assumptions Used to Estimate Fair Value of Options Granted and Shares Purchased (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Employees Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate	0.04%	0.10%
Risk-free rate, minimum			0.04%	0.10%
Risk-free rate, maximum			0.10%	1.60%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Expected life of option (in years)	6 months	6 months	6 months	6 months
Volatility, minimum	71.00%	105.00%	71.00%	105.00%
Volatility, maximum	78.00%	124.00%	78.00%	124.00%
Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate		0.50%
Risk-free rate, minimum	1.20%		0.80%	0.50%
Risk-free rate, maximum	1.30%		1.30%	1.40%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Expected life of option (in years)	7 years
Volatility	86.00%
Volatility, minimum		86.00%	74.00%	84.00%
Volatility, maximum		87.00%	86.00%	87.00%
Stock Option Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of option (in years)		7 years	7 years	7 years
Stock Option Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of option (in years)		7 years 3 months 18 days	7 years 3 months 18 days	7 years 3 months 18 days

Term Loan - Additional Informat

Term Loan - Additional Information (Detail) - USD ($)	1 Months Ended
	May 31, 2021	Dec. 31, 2019	Nov. 30, 2018	Feb. 28, 2018	Jul. 31, 2016	Jun. 30, 2021
Debt Instrument [Line Items]
Loan modification fee	$ 712,500	$ 825,000
Oxford Finance LLC Term Loan [Member]
Debt Instrument [Line Items]
Secured term loan					$ 20,000,000
Term loan repayment description					As amended, the Loan Agreement provides for interest only payments through June 1, 2023, followed by consecutive monthly payments of principal and interest in arrears starting on June 1, 2023 and continuing through the maturity date of the term loan of September 1, 2025
First principal payment date					Jun. 1, 2023
Term loan, maturity date					Sep. 1, 2025
Interest rate on term loan					7.95%	7.95%
Term loan, floating interest rate basis					an index rate plus a spread
Facility fee paid at final payment					$ 150,000
Percentage of an additional payment equal to principal amount					10.00%
Debt offering/issuance costs					$ 2,000,000
Loan modification fee			$ 900,000	$ 100,000
Oxford Finance LLC Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee					0.75%
Oxford Finance LLC Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee					2.50%

Term Loan - Schedule of Future

Term Loan - Schedule of Future Maturities and Interest Payments due under Term Loan (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Future maturities and interest payments under the term loan:
Six months ended December 31, 2021	$ 813
2022	1,612
2023	7,191
2024	9,408
2025	7,885
Total minimum payments	26,909
Less amount representing interest	(5,088)
Gross balance of term loan	21,821
Less unamortized debt discount	(1,461)
Carrying value of term loan, net	20,360
Less term loan, current portion, net		$ (884)
Term loan, non-current portion, net	$ 20,360	$ 19,936

Commitments - Summary of Lease

Commitments - Summary of Lease Arrangements of Company Facilities (Detail)	6 Months Ended
	Jun. 30, 2021ft²
Vacaville, CA [Member] | Manufacturing [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet	24,634
Expiration	Lease expires 2023
Lease expiration year	2023
Cupertino, CA [Member] | Office, Laboratory and Manufacturing [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Lease expiration year	2024
Lease renewal term	5 years
Cupertino, CA [Member] | Office, Laboratory and Manufacturing [Member] | Lease Amendment [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet	30,149
Expiration	Lease expires 2024 (with an option to renew for an additional five years)
Cupertino, CA [Member] | Office and Laboratory [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Lease expiration year	2024
Lease renewal term	5 years
Cupertino, CA [Member] | Office and Laboratory [Member] | Lease Amendment [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet	20,100
Expiration	Lease expires 2024 (with an option to renew for an additional five years)

Commitments - Additional Inform

Commitments - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Rent expenses of operating leases	$ 478,000	$ 483,000	$ 957,000	$ 968,000

Commitments - Schedule of Futur

Commitments - Schedule of Future Operating Lease Minimum Payments (Detail) $ in Thousands	Jun. 30, 2021USD ($)
Leases [Abstract]
Six months ended December 31, 2021	$ 946
2022	1,991
2023	1,970
2024	275
Total operating leases future minimum payments	$ 5,182

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jul. 28, 2021	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from sale of common stock, net of commission				$ 51,212,000	$ 8,108,000
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered							$ 175,000,000
Cantor Fitzgerald Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from sale of common stock, net of commission	$ 45,600,000
Sale of stock number of shares issued in transaction	20,364,582
Sale of stock price per share	$ 2.2386
Common stock issuance costs	$ 195,000,000
Gross proceeds from sale of common stock	$ 45,400,000
2015 Sales Agreement [Member] | IPO [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for sale						$ 56,200,000
2015 Sales Agreement [Member] | Cantor Fitzgerald Co [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered							$ 75,000,000
2018 Registration Statement and 2015 Sales Agreement [Member] | Cantor Fitzgerald Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from sale of common stock, net of commission			$ 6,200,000	$ 2,400,000	$ 6,200,000
Sale of common stock during period		0	2,610,375,000	950,009,000	2,610,375,000
Common stock weighted average price			$ 2.45	$ 2.60	$ 2.45
2018 Registration Statement [Member] | Maximum [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for sale						$ 95,600,000

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Detail) - Evonik [Member] $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Asset purchase agreement subject to certain adjustments paid	$ 15
Gain from discontinued operations	$ 12.8

Discontinued Operations - Summa

Discontinued Operations - Summary of Discontinued Operations Reported in Statement of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		$ 1,346		$ 2,526
Operating expenses:
Cost of product revenues		711		1,547
Research and development		118		248
Selling, general and administrative		103		112
Total costs and expenses		932		1,907
Net income from discontinued operations		$ 414		$ 619
Net income per share
Basic and diluted		$ 0		$ 0
Weighted-average shares used in computing net income per share
Basic	227,428	196,866	222,510	196,306
Diluted	227,428	207,477	222,510	206,111
Product Revenue, Net [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues		$ 1,346		$ 2,526

Discontinued Operations - Sum_2

Discontinued Operations - Summary of Non-cash Items Related to Discontinued Operations Included in Statement of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Disposal Group Not Discontinued Operation Income Statement Disclosures [Abstract]
Depreciation	$ 49	$ 99
Stock-based compensation expense	28	55
Non-cash items, net	$ 77	$ 154