DURECT (DRRX) 10-K 8 Mar 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2022	Mar. 03, 2023	Jun. 30, 2022
Document Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Trading Symbol	DRRX
Entity Registrant Name	DURECT CORP
Entity Central Index Key	0001082038
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Common Stock, Shares Outstanding		24,484,867
Entity Public Float			$ 107,820,564
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity File Number	000-31615
Entity Incorporation, State or Country Code	DE
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 Address, Postal Zip Code	95014
City Area Code	408
Local Phone Number	777-1417
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference	Part III incorporates information by reference from the definitive Proxy Statement for the 2022 annual meeting of stockholders, which is expected to be filed not later than 120 days after the Registrant’s fiscal year ended December 31, 2022.
Auditor Name	ERNST & YOUNG LLP
Auditor Location	San Francisco, California
Auditor Firm ID	42

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 43,483	$ 49,844
Short-term investments		19,966
Accounts receivable (net of allowances of $21 at December 31, 2022 and $15 at December 31, 2021)	3,423	6,477
Inventories, net	2,113	1,870
Prepaid expenses and other current assets	2,375	3,580
Total current assets	51,394	81,737
Property and equipment, net	188	227
Operating lease right-of-use assets	1,943	3,446
Goodwill	6,169	6,169
Long-term restricted investments	150	150
Other long-term assets	256	261
Total assets	60,100	91,990
Current liabilities:
Accounts payable	3,106	1,311
Accrued liabilities	7,896	6,799
Deferred revenue, current portion		98
Term loan, current portion, net	21,170
Operating lease liabilities, current portion	1,832	1,848
Total current liabilities	34,004	10,056
Deferred revenue, non-current portion		812
Operating lease liabilities, non-current portion	260	1,824
Term loan, non-current portion, net		20,632
Other long-term liabilities	851	884
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value: 10,000 shares authorized; none issued and outstanding
Common stock, $0.0001 par value: 150,000 shares and 35,000 shares authorized at December 31, 2022 and 2021, respectively; 22,785 and 22,768 shares issued and outstanding at December 31, 2022 and 2021, respectively	23	23
Additional paid-in capital	586,357	583,818
Accumulated other comprehensive loss	(13)	(10)
Accumulated deficit	(561,382)	(526,049)
Stockholders’ equity	24,985	57,782
Total liabilities and stockholders’ equity	$ 60,100	$ 91,990

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Allowances for accounts receivable	$ 21	$ 15
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	35,000,000
Common stock, shares issued	22,785,000	22,768,000
Common stock, shares outstanding	22,785,000	22,768,000

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Total revenues	$ 19,283	$ 13,977	$ 30,111
Operating expenses:
Cost of product revenues	$ 1,588	$ 1,955	$ 1,406
Type of cost, good or service [extensible list]	Product Revenue, Net [Member]	Product Revenue, Net [Member]	Product Revenue, Net [Member]
Research and development	$ 36,862	$ 31,846	$ 27,709
Selling, general and administrative	15,915	14,449	13,611
Total operating expenses	54,365	48,250	42,726
Loss from operations	(35,082)	(34,273)	(12,615)
Other income (expense):
Interest and other income	2,148	156	517
Interest expense	(2,399)	(2,148)	(2,237)
Net other expense	(251)	(1,992)	(1,720)
Loss from continuing operations	(35,333)	(36,265)	(14,335)
Income from discontinued operations (Note 11)			13,753
Net loss	(35,333)	(36,265)	(582)
Net change in unrealized loss on available-for-sale securities, net of tax	(3)	(5)	(2)
Total comprehensive loss	$ (35,336)	$ (36,270)	$ (584)
Basic
Loss from continuing operations	$ (1.55)	$ (1.61)	$ (0.72)
Income from discontinued operations			0.69
Net income per share, Basic	(1.55)	(1.61)	(0.03)
Diluted
Loss from continuing operations	(1.55)	(1.61)	(0.72)
Income from discontinued operations			0.69
Net income per share, diluted	$ (1.55)	$ (1.61)	$ (0.03)
Weighted-average shares used in computing net income per share, Basic	22,777	22,505	19,946
Weighted-average shares used in computing net income per share, diluted	22,777	22,505	19,946
Collaborative Research and Development and Other Revenue [Member]
Total revenues	$ 13,204	$ 6,331	$ 23,941
Product Revenue, Net [Member]
Total revenues	$ 6,079	$ 7,646	$ 6,170

Statements of Stockholders' Equ

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		19,526,000
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	3,381		3,381
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		297,000
Issuance of common stock upon equity financings, net of issuance costs	12,283	$ 1	12,282
Issuance of common stock upon equity financings, net of issuance cost, shares		530,000
Stock-based compensation expense from stock options and ESPP shares	2,175		2,175
Net loss	(582)				(582)
Change in unrealized loss on available-for-sale securities, net of tax	(2)			(2)
Ending balance at Dec. 31, 2020	40,115	$ 20	529,884	(5)	(489,784)
Ending balance, shares at Dec. 31, 2020		20,353,000
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	3,587	$ 1	3,586
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		283,000
Issuance of common stock upon equity financings, net of issuance costs	47,660	$ 2	47,658
Issuance of common stock upon equity financings, net of issuance cost, shares		2,132,000
Stock-based compensation expense from stock options and ESPP shares	2,690		2,690
Net loss	(36,265)				(36,265)
Change in unrealized loss on available-for-sale securities, net of tax	(5)			(5)
Ending balance at Dec. 31, 2021	57,782	$ 23	583,818	(10)	(526,049)
Ending balance, shares at Dec. 31, 2021		22,768,000
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	59		59
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		14,000
Issuance of common stock upon equity financings, net of issuance costs	25		25
Issuance of common stock upon equity financings, net of issuance cost, shares		3,000
Stock-based compensation expense from stock options and ESPP shares	2,455		2,455
Net loss	(35,333)				(35,333)
Change in unrealized loss on available-for-sale securities, net of tax	(3)			(3)
Ending balance at Dec. 31, 2022	$ 24,985	$ 23	$ 586,357	$ (13)	$ (561,382)
Ending balance, shares at Dec. 31, 2022		22,785,000

Statements of Stockholders' E_2

Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Stockholders' Equity [Abstract]
Stock issuance costs	$ 0	$ 395	$ 380

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net loss		$ (35,333)	$ (36,265)	$ (582)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on sale of equipment			(11)
Depreciation and accretion		119	288	297
Stock-based compensation		2,457	2,688	2,170
Inventory write-down				194
Amortization of debt issuance cost		479	451	453
Net accretion/amortization on investments		16	(76)	(313)
Changes in operating lease liabilities		(77)	(22)	(61)
Gain on sale of LACTEL product line				(12,845)
Changes in assets and liabilities:
Accounts receivable		3,054	(5,440)	389
Inventories		(245)	(4)	(249)
Prepaid expenses and other assets		1,210	965	(2,178)
Accounts payable		1,795	(367)	(241)
Accrued liabilities		1,155	384	(3,059)
Deferred revenue		(910)	98	(22,679)
Total adjustments		9,053	(1,046)	(38,122)
Net cash used in operating activities		(26,280)	(37,311)	(38,704)
Cash flows from investing activities
Purchases of property and equipment		(111)	(194)	(208)
Purchases of available-for-sale securities			(52,298)	(45,066)
Proceeds from maturities of available-for-sale securities		19,947	48,830	54,706
Proceeds from sales of available-for-sale securities			3,994
Net proceeds from sale of LACTEL product line			14,979
Net cash provided by investing activities		19,836	15,311	9,432
Cash flows from financing activities
Payments on equipment financing obligations		(1)	(2)	(4)
Net proceeds from issuances of common stock upon exercise of stock options, and purchases of ESPP shares		59	3,587	3,381
Net proceeds from issuances of common stock in connection with equity financings		25	47,660	12,283
Term loan amendment cost			(713)
Net cash provided by financing activities		83	50,532	15,660
Net (decrease) increase in cash and cash equivalents		(6,361)	28,532	(13,612)
Cash, cash equivalents, and restricted cash, beginning of the period	[1]	49,994	21,462	35,074
Cash, cash equivalents, and restricted cash, end of the period	[1]	43,633	49,994	21,462
Supplemental disclosure of cash flow information
Cash paid for interest		$ 1,800	$ 1,617	1,678
Supplementary disclosure of non-cash investing and financing information
Cash held in escrow				$ 14,979
[1] Includes restricted cash of $ 150,000 (presented as long-term restricted investments) on the balance sheets at each of December 31, 2022, 2021 and 2020.

Statements of Cash Flows (Paren

Statements of Cash Flows (Parenthetical) - Long Term Restricted Investments [Member] - USD ($)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Restricted Cash and Cash Equivalents, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Restricted Investments, Noncurrent	Restricted Investments, Noncurrent	Restricted Investments, Noncurrent
Restricted cash	$ 150,000	$ 150,000	$ 150,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	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 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. Basis of Presentation and Use of Estimates The Company’s financial statements have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP). The preparation of the accompanying Financial Statements conforms to accounting principles generally accepted in the U.S. which requires management to make judgments, estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosures. On an ongoing basis, management evaluates its estimates including, but not limited to, those related to revenue recognition, the period of performance, identification of performance obligations and evaluation of milestones with respect to our collaborations, the amounts of revenues, recoverability of inventory, certain accrued liabilities including accrued clinical costs, asset retirement obligations, and stock-based compensation. The Company bases its estimates on historical experience and on various other market-specific and other relevant assumptions that the Company believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates. Reverse Stock Split On December 5, 2022, the Company effected a 1-for- 10 reverse stock split of its outstanding common stock. The reverse stock split also affected our outstanding stock options, purchase rights and equity incentive plans and resulted in the shares underlying such instruments being reduced and the exercise price being increased proportionately. For all financial statement periods presented, references to number of shares, net loss per share, stock price and exercise price have been conformed to reflect the effects of the Company’s 1-for- 10 reverse stock split , effective December 5, 2022, unless otherwise specified herein. Discontinued Operations On December 31, 2020, the Company sold its LACTEL Absorbable Polymer (LACTEL) product line to Evonik. The accompanying financial statements have been recast to reflect the assets, liabilities, revenue and expenses related to the Company’s LACTEL product line as discontinued operations for the years ended December 31, 2020 (see Note 11). The Company believes this format provides comparability with its previously filed financial statements. Liquidity and Need to Raise Additional Capital As of December 31, 2022, the Company has an accumulated deficit of $ 561.4 million as well as negative cash flows from operating activities. Presently, the Company does not have sufficient cash resources to meet its plans for the next twelve months following the issuance of these financial statements. The Company will continue to require substantial funds to continue research and development, including clinical trials of its product candidates. These factors raise substantial doubt regarding the Company’s ability to continue as a going concern for a period of one year from the issuance of these financial statements. Management’s plans in order to meet its operating cash flow requirements include seeking additional collaborative agreements for certain of its programs 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 and that the Company will succeed in its future operations. If the Company cannot successfully raise additional capital and implement its strategic development plan, its liquidity, financial condition and business prospects will be materially and adversely affected, and the Company may have to cease operations. As further described in Note 8, the Company reclassified the remaining balance of its term loan to current liabilities from non-current liabilities on the Company’s balance sheet as of December 31, 2022 due to recurring losses, liquidity concerns and a subjective acceleration clause in the Company’s Loan Agreement. These financial statements have been prepared on a going concern basis and do not include any adjustments to the amounts and classification of assets and liabilities that may be necessary in the event the Company can no longer continue as a going concern. Cash, Cash Equivalents and Investments The Company considers all highly liquid investments with maturities of 90 days or less from the date of purchase to be cash equivalents. Investments with original maturities of greater than 90 days from the date of purchase but less than one year from the balance sheet date are classified as short-term investments, while investments with maturities in one year or beyond one year from the balance sheet date are classified as long-term investments. Management determines the appropriate classification of its cash equivalents and investment securities at the time of purchase and re-evaluates such determination as of each balance sheet date. Management has classified the Company’s cash equivalents and investments as available-for-sale securities in the accompanying financial statements. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported as a component of accumulated other comprehensive loss. Realized gains and losses are included in interest income. There were no material realized gains or losses in the periods presented. The cost of securities sold is based on the specific identification method. The Company invests in debt instruments of government agencies, corporations, and money market funds with high credit ratings. The Company has established guidelines regarding diversification of its investments and their maturities with the objectives of maintaining safety and liquidity, while maximizing yield. Total cash held in escrow (related to the sale of the LACTEL product line) was $ 15 million as of December 31, 2020; the $ 15 million was released from escrow in January 2021. Concentrations of Credit Risk Financial instruments that potentially subject the Company to credit risk consist principally of interest-bearing investments and trade receivables. The Company maintains cash, cash equivalents and investments with various major financial institutions. The Company performs periodic evaluations of the relative credit standing of these financial institutions. In addition, the Company performs periodic evaluations of the relative credit quality of its investments. Pharmaceutical companies and academic institutions account for a substantial portion of the Company’s trade receivables. The Company provides credit in the normal course of business to its customers and collateral for these receivables is generally not required. The risk associated with this concentration is limited to a certain extent due to the large number of accounts and their geographic dispersion. The Company monitors the creditworthiness of its customers to which it grants credit terms in the normal course of business. The Company maintains reserves for estimated credit losses and, to date, such losses have been immaterial in all periods presented. Customer and Product Line Concentrations Revenue from the sale of products from the ALZET product line accounted for 31 %, 46 % and 20 % of total revenue for 2022, 2021 and 2020, respectively. Innocoll accounted for 52 % and 37 % of the Company’s total revenue for 2022 and 2021, respectively. Gilead accounted for 76 % of the Company’s total revenue for 2020. Total revenue by geographic region for the years 2022, 2021 and 2020 are as follows (in thousands): Year ended December 31, 2022 2021 2020 United States $ 5,447 $ 5,690 $ 26,894 Europe 11,791 6,630 1,386 Japan 1,488 1,015 1,174 Others 557 642 657 Total $ 19,283 $ 13,977 $ 30,111 Revenue by geography is determined by the location of the customer. Allowance for Doubtful Account s Allowance for doubtful accounts as of December 31, 2022, 2021 and 2020 were comprised as follows (in thousands): Balance at Additions (Reductions) to allowances Deductions Balance at Allowance for doubtful accounts Year ended December 31, 2022 $ ( 15 ) $ ( 6 ) $ — $ ( 21 ) Year ended December 31, 2021 $ ( 72 ) $ 56 $ 1 $ ( 15 ) Year ended December 31, 2020 $ ( 27 ) $ ( 46 ) $ 1 $ ( 72 ) 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 a 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 or little associated cost of goods for these materials. The Company’s inventories consisted of the following (in thousands): December 31, 2022 2021 Raw materials $ 168 $ 143 Work in-process 1,151 712 Finished goods 794 1,015 Total inventories $ 2,113 $ 1,870 Property and Equipment Property and equipment are stated at cost less accumulated depreciation, which is computed using the straight-line method over the estimated useful lives of the assets, which range from three to five years . Leasehold improvements are amortized using the straight-line method over the estimated useful lives of the assets, or the terms of the related leases, whichever are shorter. Goodwill Goodwill is periodically assessed and evaluated for impairment. The Company operates in one operating segment and also has only one reporting unit, which is the research, development and manufacturing of pharmaceutical products. The Company assesses the impairment of goodwill at least annually and whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Factors the Company considers important which could trigger an impairment review include the following: • significant decline in our stock price for a prolonged period; • our market capitalization relative to net book value; • new information affecting the commercial value of the asset; • significant underperformance relative to historical or projected future operating results; • significant changes in the manner of our use of the acquired assets or the strategy for the Company’s overall business; and • significant negative industry or economic trends. The Company evaluates goodwill for impairment at least annually. To date, the Company has not recorded any impairment charge related to goodwill. Impairment of Long-Lived Assets The Company reviews long-lived assets, including property and equipment, intangible assets, and other long-term assets, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition is less than its carrying amount. Impairment, if any, is calculated as the amount by which an asset’s carrying value exceeds its fair value, typically using discounted cash flows to determine fair value. Through December 31, 2022, there have been no material impairment losses. Leases ASC 842 requires the Company to recognize an operating lease right-of-use asset and corresponding operating lease liability for the Company’s leased properties. The Company’s operating lease right-of-use assets and liabilities are recognized under ASC 842 based on the present value of lease payments over the remaining lease term at the lease commencement date. In determining the net present value of lease payments, we estimate the incremental borrowing rate based on the information available, including remaining lease term. As of December 31, 2022, the weighted-average remaining lease term was 0.99 years for the Company’s leased properties. Stock-Based Compensation The Company accounts for share-based payments using a fair-value based method for costs related to all share-based payments, including stock options and stock issued under the Company’s employee stock purchase plan (ESPP). The Company estimates the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company recognizes compensation costs on a straight-line basis over the requisite service period and accounts for forfeitures as they occur. See Note 9 for further information regarding stock-based compensation. Revenue Recognition Product Revenue, Net The Company manufacture and sell ALZET osmotic pumps used in laboratory research, and manufacture and sell certain excipients used by pharmaceutical companies as raw materials in certain of their products, including POSIMIR, an animal health product and Methydur. 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: The Company generally offers customers a limited right of return for products that have been purchased. The Company estimates the amount of its product sales that are probable of being 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 primarily using its historical sales information. The Company expects 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 or products 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, intellectual property and commercial milestone payments; payments for manufacturing supply services the Company provides itself or 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 and earn-out revenues, 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. For arrangements that are determined to include multiple performance obligations, the Company must develop assumptions that require judgment to determine the estimated stand-alone selling price for each performance obligation identified. These assumptions 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 the transaction price 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 performance obligations comprised of licenses that are bundled with other promises, the Company utilizes its 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 Company applies an appropriate method of measuring progress for purposes of recognizing related revenues from the allocated transaction price. For performance obligations recognized over time, the Company evaluates the measure of progress each reporting period and recognizes revenues on a cumulative catch-up basis as collaborative research and development revenues. 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. Manufacturing Supply Services: Arrangements that include a promise for future supply of raw materials or 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 and allocated a portion of the transaction price based on the estimated standalone selling price of the material right. If the Company is entitled to additional payments when the customer exercises these options, the deferred transaction price and any additional payments are recorded in collaborative research and development revenue when the customer obtains control of the goods. Royalties and Earn-outs: For arrangements that include sales-based royalties or earn-outs, including milestone payments based on first commercial sale or 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 revenues from any of the Company’s agreements. Research and development services: Revenue from research and development services that are determined to represent a distinct performance obligation with the Company’s third-party collaborators is recognized over time as the related research and development services are performed using an appropriate method of measuring progress. The Company evaluates the measure of progress each reporting period and recognizes revenue on a cumulative catch-up basis, as collaborative research and development revenue. Research and development expenses under the collaborative research and development agreements generally approximate or exceed the revenue recognized under such agreements over the term of the respective agreements. Deferred revenue may result when the Company does not expend the required level of effort during a specific period in comparison to funds received under the respective agreement. 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. Prepaid and Accrued Clinica l Costs The Company incurs significant costs associated with third party consultants and organizations for pre-clinical studies, clinical trials, contract research, 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. Estimates are determined each reporting period by reviewing the terms and conditions of the underlying contracts, reviewing open purchase orders and by having detailed discussions with internal clinical personnel and third-party service providers as to the nature and status of the services performed in relation to amounts billed. The costs for unbilled services are estimated by applying the rates and fees applicable in the underlying contracts. If these good faith estimates are inac curate, actual expenses incurred could materially differ from these estimates. Prepaid and Accrued Manufacturing Costs The Company incurs significant costs associated with third party consultants and organizations for manufacturing, validation, testing 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. Estimates are determined each reporting period by reviewing the terms and conditions of the underlying contracts, reviewing open purchase orders and by having detailed discussions with internal personnel and third-party service providers as to the nature and status of the services performed in relation to amounts billed. The costs for unbilled services are estimated by applying the rates and fees applicable in the underlying contracts. If these good faith estimates are inaccurate, actual expenses incurred could materially differ from these estimates. Research and Development Expenses 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, research and development expenses incurred that are reimbursed by the Company’s partners are recorded as collaborative research and development revenue. Comprehensive Loss 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 Operations and Comprehensive Loss. Segment Reporting The Company operates in one operating segment, which is the research, development and manufacturing of pharmaceutical products. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding. Diluted net loss 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 per share were as follows (in thousands except per share amounts): Year Ended December 31, 2022 2021 2020 Numerators: Net loss $ ( 35,333 ) $ ( 36,265 ) $ ( 582 ) Denominators: Weighted average shares used to compute basic 22,777 22,505 19,946 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute diluted 22,777 22,505 19,946 Net loss per share: Basic $ ( 1.55 ) $ ( 1.61 ) $ ( 0.03 ) Diluted $ ( 1.55 ) $ ( 1.61 ) $ ( 0.03 ) The computation of diluted net loss per share for 2022, 2021 and 2020 excludes the impact of options to purchase 2.8 million, 834,000 and 752,000 shares of common stock outstanding at December 31, 2022, 2021 and 2020, respectively, as such impact would be antidilutive. Shipping and Handling Costs related to shipping and handling are included in cost of revenues for all periods presented. 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 adopted the standard on January 1, 2023 and the adoption did not have a material effect on the financial statements. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. In response to concerns about structural risks of the cessation of London Interbank Offered Rate (LIBOR), the amendments in this ASU provide optional guidance for a limited time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendments in this ASU provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU apply only to contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022. The amendments in this ASU are elective and are effective for all entities as of March 12, 2020 through December 31, 2022. The adoption of the standard did not have a material effect on the financial statements.

Strategic Agreements

Strategic Agreements	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Strategic Agreements	2. Strategic Agreements The collaborative research and development and other revenue associated with the Company’s major third-party collaborators are as follows (in thousands): Year ended December 31, 2022 2021 2020 Collaborator/Counterparty Innocoll (1) $ 10,015 $ 4,100 $ — Gilead (2) — — 22,879 Other (3) 3,189 2,231 1,062 Total collaborative research and development and other revenue $ 13,204 $ 6,331 $ 23,941 (1) The Company signed a license agreement with Innocoll on December 21, 2021, pursuant to which Innocoll agreed to pay a nonrefundable upfront license fee of $ 4.0 million and $ 1.3 million primarily for the sale of manufacturing supplies and excipients. In December 2021, upon the transfer of control of the license, the manufacturing supplies and excipients, and equipment to Innocoll, the Company recognized $ 4.1 million as collaborative research and development and other revenue, $ 1.1 million as product revenue, and a reduction of $ 0.1 million in net equipment. In the twelve months ended December 31, 2022, the Company recognized $ 8.0 million of patent milestone revenue and $ 2.0 million of first commercial sale milestone revenue under the license agreement with Innocoll. (2) The Company signed a license agreement with Gilead on July 19, 2019. Amounts related to recognition of upfront fees and milestone payments were zero , zero and $ 22.7 million for the twelve months ended December 31, 2022, 2021 and 2020, respectively. The Company received a nonrefundable upfront license fee and a milestone payment totaling $ 35.0 million in 2019 which was being recognized as revenue as its obligation was being satisfied using the cost-to-cost input method. In June 2020, the Company received notice that Gilead was terminating the License Agreement and a related R&D agreement between Gilead and the Company. 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. Amounts recognized as revenue during the twelve months ended December 31, 2020 also included the Company’s reimbursable collaborative research and development services performed under its agreement with Gilead. (3) Includes: (a) amounts related to earn-out revenue from Indivior UK Limited (Indivior) with respect to PER SERIS net sales; (b) royalty revenue from OP Pharma with respect to Methydur net sales; and (c) revenue from other agreements, including research and development activities funded by our collaborators and recognition of deferred revenue. As of December 31, 2022, the Company had potential milestones of up to $ 122.0 million that the Company may receive in the future under its collaborative arrangements, of which $ 10.0 million are development-based milestones, $ 2.0 million are patent-based milestones and $ 110.0 million are sales-based milestones. Within the category of development-based milestones, $ 10.0 million are related to regulatory approvals. In January 2023, the Company received a $ 2.0 million sales-based milestone payment that was achieved in September 2022 for the first commercial sale of POSIMIR by Innocoll. Agreement with Innocoll On December 21, 2021, the Company entered into a license agreement (the “Innocoll Agreement”) with Innocoll Pharmaceuticals Limited (“Innocoll”). Pursuant to the Innocoll Agreement, the Company has granted Innocoll an exclusive, royalty-bearing, sublicensable right and license to develop, manufacture and commercialize in the United States, POSIMIR ® , the Company’s FDA-approved post-surgical pain product, with respect to all uses and applications in humans. The Innocoll Agreement provides for the assignment of the Company’s supply agreement with its contract manufacturing organization to Innocoll and also provides Innocoll with the right, within the United States, to expand the approved indications of POSIMIR. The Company retains, outside the United States, all of the global rights to POSIMIR. Upon execution of the Innocoll Agreement, Innocoll paid the Company an initial nonrefundable, upfront fee of $ 4.0 million as well as a fee in the amount of $ 1.3 million primarily to cover the manufacturing supplies and excipients and certain equipment transferred to Innocoll pursuant to the terms of the Innocoll Agreement, and certain recently incurred DURECT expenses the parties negotiated for Innocoll to reimburse. The Innocoll Agreement includes customary representations and warranties on behalf of the Company and Innocoll, including representations as to the licensed intellectual property, regulatory matters and compliance with applicable laws. The Innocoll Agreement also provides for certain mutual indemnities for breaches of representations, warranties and covenants. The Company also evaluated Innocoll’s future purchases of an excipient from the Company and concluded that these purchases are option rights, and are at market rates, and do not constitute a material right performance obligation. As such, these future purchases have been excluded from the allocation of transaction price and the Company will account for them as separate contracts when and if Innocoll elects to issue purchase orders for the excipient. During December 2021, the upfront fee of $ 4.0 million as well as a fee in the amount of $ 1.2 million to cover reimbursed expenses, the manufacturing supplies and excipients transferred to Innocoll pursuant to the terms of the Innocoll Agreement was recognized as revenue when the performance obligations were satisfied in December 2021 and $ 0.1 million was recorded as a net reduction in equipment in December 2021. At December 31, 2021, the Company included $ 5.3 million due from Innocoll in accounts receivable on its balance sheet; these funds were received in January 2022. In August 2022, the Company was issued a new patent by the U.S. Patent and Trademark Office, extending U.S. patent coverage of POSIMIR to at least 2041, resulting in an $ 8.0 million milestone payment by Innocoll to the Company. In September 2022, Innocoll launched POSIMIR in the U.S., triggering a $ 2.0 million milestone payment to the Company for the first commercial sale of POSIMIR. Thus, the Company recognized $ 10.0 million of milestone revenue under the agreement with Innocoll during the twelve months ended December 31, 2022. As the commercial launch of POSIMIR progresses, the Company will receive tiered, low double-digit to mid-teen royalties on net product sales of POSIMIR in the United States. The Company may earn additional milestone payments of up to $ 122.0 million in the aggregate, depending on the achievement of certain regulatory, commercial, and intellectual property milestones with respect to POSIMIR. Agreement with Gilead Sciences, Inc. On July 19, 2019, the Company entered into a license agreement (the “Gilead Agreement”) with Gilead Sciences, Inc. (“Gilead”). Pursuant to the Gilead Agreement, the Company granted Gilead the exclusive worldwide rights to develop and commercialize a long-acting injectable HIV product utilizing DURECT’s SABER ® technology. Gilead also received exclusive access to the SABER platform for HIV and Hepatitis B Virus (HBV) and the exclusive option to license additional SABER-based products directed to HIV and HBV. Under the terms of the Gilead Agreement, Gilead made a non-refundable upfront payment to DURECT of $ 25 million, and in October 2019, the Company also received a $ 10 million milestone payment from Gilead for further development of the product candidate. During the twelve months ended December 31, 2019, the upfront and milestone consideration of $ 35 million received in 2019 associated with the Primary Services was being recognized as revenue when the first performance obligation was being satisfied using the cost-to-cost input method, which the Company believes best depicts the transfer of control to the customer. Under the cost-to-cost input method, the extent of progress towards completion is measured based on the ratio of actual costs incurred to the total estimated costs. Revenue is recorded as a percentage of the transaction price based on the extent of progress towards completion. The estimate of the Company’s measure of progress, which can include additional Primary Services, if any, and the estimate of any additional consideration for those additional Primary Services, are included in the transaction price which is updated at each reporting date, and revenue is recognized on a cumulative catchup basis. As such, management applies a certain amount of judgment in estimating both the Primary Services and the corresponding timeline through completion of the first performance obligation, which are key inputs when using the cost-to-cost input method. During the twelve months ended December 31, 2019, the Company recognized $ 12.3 million of the deferred revenue within collaborative research and development and other revenue. The Company also recognized $ 4.8 million from Gilead during the twelve months ended December 31, 2019 from feasibility related collaborative research and development services. In June 2020, Gilead terminated the Gilead Agreement and a related R&D agreement between Gilead and the Company. As a result, the Company recognized $ 22.7 million as revenue during the year ended December 31, 2020, which represented all of the remaining upfront fee and milestone payment that had previously been deferred 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. Patent Purchase Agreement with Indivior In September 2017, we entered into an agreement with Indivior (the “Indivior Agreement”), under which we assigned to Indivior certain patents that may provide further intellectual property protection for PERSERIS, Indivior’s extended-release injectable suspension for the treatment of schizophrenia in adults. In consideration for such assignment, Indivior made non-refundable upfront and milestone payments to DURECT totaling $ 17.5 million. Additionally, under the terms of the agreement with Indivior, DURECT receives quarterly earn-out payments into 2026 that are based on a single digit percentage of U.S. net sales of PERSERIS. Indivior commercially launched PERSERIS in the U.S. in February 2019. The Indivior Agreement contains customary representations, warranties and indemnities of the parties. Amounts recognized during the twelve months ended December 31, 2022, 2021 and 2020 related to earn-out revenues from PERSERIS have been immaterial and are included in collaborative research and development and other revenue.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Financial Instruments	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. The following table sets forth the fair value of the Company’s financial assets that were measured at fair value on a recurring basis as of December 31, 2022 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 633 $ — $ — $ 633 Certificates of deposit — 150 — 150 Commercial paper — 40,465 — 40,465 Total $ 633 $ 40,615 $ — $ 41,248 The following table sets forth the fair value of our financial assets that were measured at fair value on a recurring basis as of December 31, 2021 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 2,089 $ — $ — $ 2,089 Certificates of deposit — 150 — 150 Commercial paper — 62,495 — 62,495 U.S. Government agencies — 1,293 — 1,293 Total $ 2,089 $ 63,938 $ — $ 66,027 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 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 December 31, 2022 is less than twelve months and these investments are rated by S&P and Moody’s at AAA or AA- for securities and A1 or P1 for commercial paper. The following is a summary of available-for-sale securities as of December 31, 2022 and 2021 (in thousands): December 31, 2022 Amortized Unrealized Unrealized Estimated Money market funds $ 633 $ — $ — $ 633 Certificates of deposit 150 — — 150 Commercial paper 40,478 — ( 13 ) 40,465 $ 41,261 $ — $ ( 13 ) $ 41,248 Reported as: Cash and cash equivalents $ 41,111 $ — $ ( 13 ) $ 41,098 Long-term restricted investments 150 — — 150 $ 41,261 $ — $ ( 13 ) $ 41,248 December 31, 2021 Amortized Unrealized Unrealized Estimated Money market funds $ 2,089 $ — $ — $ 2,089 Certificates of deposit 150 — — 150 Commercial paper 62,505 — ( 10 ) 62,495 Corporate debt 1,293 — — 1,293 $ 66,037 $ — $ ( 10 ) $ 66,027 Reported as: Cash and cash equivalents $ 45,913 $ — $ ( 2 ) $ 45,911 Short-term investments 19,974 — ( 8 ) 19,966 Long-term restricted investments 150 — — 150 $ 66,037 $ — $ ( 10 ) $ 66,027 The following is a summary of the cost and estimated fair value of available-for-sale securities at December 31, 2022, by contractual maturity (in thousands): December 31, 2022 Amortized Estimated Mature in one year or less $ 40,478 $ 40,465 Mature after one year through five years 150 150 $ 40,628 $ 40,615 There were no securities that have had an unrealized loss for more than 12 months as of December 31, 2022. As of December 31, 2022, 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.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment consist of the following (in thousands): December 31, 2022 2021 Equipment $ 10,791 $ 10,696 Leasehold improvements 8,490 8,474 19,281 19,170 Less accumulated depreciation and amortization ( 19,093 ) ( 18,943 ) Property and equipment, net $ 188 $ 227 Depreciation expense was $ 150,000 , $ 132,000 and $ 297,000 in 2022, 2021 and 2020, respectively. As of December 31, 2022 and 2021, the Company recorded $ 607,000 and $ 638,000 , respectively, as a liability which was included in other long-term liabilities on its balance sheet for asset retirement obligations associated with the estimated restoration cost for its leased buildings.

Restricted Investments

Restricted Investments	12 Months Ended
	Dec. 31, 2022
Text Block [Abstract]
Restricted Investments	5. Restricted Investments As of December 31, 2022 and 2021, the Company had $ 150,000 recorded as restricted investments, which primarily served as collateral for letters of credit securing a leased facility in California.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments	6. Commitments Operating Leases The Company has lease arrangements for its facilities in California 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 (with an option to renew for an additional five years ) 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. Rent expense under all operating leases was $ 1.9 million for each of the years ended December 31, 2022, 2021 and 2020. In determining the net present value of lease payments, the Company used its incremental borrowing rat e of 13.8 % based on the information available, including remaining lease term, at the adoption date of ASC 842. As of December 31, 2022 and 2021, the weighted-average remaining lease term was 0.99 years and 1.99 years, respectively, for the Company’s leased properties. Future minimum payments under these noncancelable leases are as follows (in thousands): Year ending December 31, Operating 2023 1,970 2024 275 2,245 Less present value adjustment ( 153 ) Operating lease liabilities recognized $ 2,092

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Liabilities	7. Accrued Liabilities Accrued liabilities as of December 31, 2022 and 2021 were comprised as follows (in thousands): December 31, 2022 2021 Accrued compensation and benefits $ 3,970 $ 4,099 Accrued clinical costs 1,966 97 Accrued contract research and manufacturing cost 861 757 Others 1,099 1,846 Total $ 7,896 $ 6,799

Term Loan

Term Loan	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Term Loan	8. Term Loan In July 2016, the Company entered into a $ 20.0 million secured single-draw term loan (as amended, the “Loan Agreement”) 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 11.45 % as of December 31, 2022) 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 sheets 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. As of December 31, 2022, the Company was in compliance with all material covenants under the Loan Agreement and there had been no material adverse change. In accordance with ASC 470-10-45-2, the term loan was reclassified to current liabilities from non-current liabilities on the Company’s balance sheet as of December 31, 2022 due to recurring losses, liquidity concerns and a subjective acceleration clause in the Company’s Loan Agreement. The fair value of the term loan approximates the carrying value. Future maturities due under the term loan as of December 31, 2022, are as follows (in thousands): 2023 $ 5,714 2024 8,571 2025 7,715 Total minimum payments 22,000 Less unamortized debt discount and accrued final payment ( 830 ) Carrying value of term loan, net 21,170

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity Common Stock In August 2018, the Company filed a new shelf registration statement on Form S-3 with the SEC, which upon being declared effective in October 2018, terminated an earlier registration statement 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 additional shares of common stock which the Company may sell, subject to certain limitations, under the 2015 Sales Agreement through Cantor Fitzgerald, acting as agent. On June 20, 2019, the Company entered into a transaction to sell 2,900,000 shares of our common stock to certain investors in a registered offering at a price of $ 5.20 per share, raising total gross proceeds to the Company of approximately $ 15.1 million. In 2020, the Company raised net proceeds of approximately $ 12.3 million from the sale of 530,800 shares of the Company’s common stock in the open market at a weighted average price of $ 23.90 per share pursuant to the October 2018 registration statement. In February 2021, the Company completed an underwritten public offering of 2,036,458 shares of its common stock at a price of $ 22.39 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. In 2019, the Company raised net proceeds of approximately $ 3.5 million from the sale of 234,982 shares of the Company’s common stock in the open market at a weighted average price of $ 15.50 per share pursuant to the October 2018 registration statement. In 2021, the Company raised net proceeds (net of commissions) of approximately $ 2.4 million from the sale of 95,000 shares of the Company’s common stock in the open market at a weighted average price of $ 26.00 per share pursuant to the 2018 Registration Statement and the 2015 Sales Agreement. In July 2021, the Company filed a shelf registration statement on Form S-3 with the SEC (the “2021 Registration Statement”) (File No. 333-258333), which upon being declared effective in August 2021, terminated the 2018 Registration Statement and allows the Company to offer up to $ 250.0 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 July 30, 2021 with Cantor Fitzgerald & Co. (the “2021 Sales Agreement”). The 2021 Sales Agreement replaced the 2015 Sales Agreement. On December 5, 2022, the Company effected a 1-for- 10 reverse stock split of its outstanding common stock. The reverse stock split also affected our outstanding stock options, purchase rights and equity incentive plans and resulted in the shares underlying such instruments being reduced and the exercise price being increased proportionately. Description of Stock-Based Compensation Plans 2000 Stock Plan (Incentive Stock Plan) In January 2000, the Company’s Board of Directors and stockholders adopted the DURECT Corporation 2000 Stock Plan, under which incentive stock options and non-statutory stock options and stock purchase rights may be granted to employees, consultants and non-employee directors. The 2000 Stock Plan was amended by written consent of the Board of Directors in March 2000 and written consent of the stockholders in August 2000. In April 2005, the Board of Directors approved certain amendments to the 2000 Stock Plan. At the Company’s annual stockholders meeting in June 2005, the stockholders approved the amendments of the 2000 Stock Plan to: (i) expand the types of awards that the Company may grant to eligible service providers under the Stock Plan to include restricted stock units, stock appreciation rights and other similar types of awards (including other awards under which recipients are not required to pay any purchase or exercise price) as well as cash awards; and (ii) include certain performance criteria that may be applied to awards granted under the Stock Plan. At the Company’s annual stockholders meeting in June 2010, the stockholders approved amendments of the 2000 Stock Plan to: (i) provide that the number of shares that remain available for issuance will be reduced by two shares for each share issued pursuant to an award (other than an option or stock appreciation right) granted on or after the date of the 2010 Annual Meeting; (ii) expand the types of transactions that might be considered repricings and option exchanges for which stockholder approval is required; (iii) provide that shares tendered or withheld in payment of the exercise price of an option or withheld to satisfy a withholding obligation, and all shares with respect to which a stock appreciation right is exercised, will not again be available for issuance under the Stock Plan; (iv) require that options and stock appreciation rights have an exercise price or base appreciation amount that is at least fair market value on the grant date, except in connection with certain corporate transactions, and that stock appreciation rights may not have longer than a 10 -year term; (v) add new performance goals that may be used to provide “performance-based compensation” under the 2000 Stock Plan; (vi) extend the term of the 2000 Stock Plan to the date that is ten ( 10 ) years following the stockholders meeting; and (vii) expand the treatment of outstanding awards in connection with certain changes of control of the Company to cover mergers in which the consideration payable to stockholders is not solely securities of the successor corporation. At the Company’s annual stockholders meeting in June 2011, June 2014, June 2016 and June 2018, the stockholders approved amendments of the 2000 Stock Plan to increase the number of shares of the Company’s common stock available for issuance by 550,000 shares, 400,000 shares, 500,000 shares and 750,000 shares, respectively, each of which had previously been approved by the Board of Directors. At the Company’s annual stockholders meeting in June 2019, the stockholders approved an amendment of the 2000 Stock Plan to extend the term of the 2000 Stock Plan to the date that is ten ( 10 ) years following the stockholders meeting. In April 2013, the Board of Directors approved certain amendments to the 2000 Stock Plan to: (i) increase the number of stock options granted to a non-employee director on the date which such person first becomes a director from 3,000 to 7,000 shares of common stock; each option shall have a ten-year term, become exercisable in installments of one-third of the total number of options granted on each anniversary of the grant and have a two-year period following termination of Director status in which the former director can exercise the option; (ii) modify the exercise period for future option grants to a non-employee director in which a former director can exercise the option following termination of Director status from a one year period to a two-year period. Options granted under the 2000 Stock Plan expire no later than ten years from the date of grant. Options may be granted with different vesting terms from time to time not to exceed five years from the date of grant. The option price of an incentive stock option granted to an employee or of a nonstatutory stock option granted to any person who owns stock representing more than 10 % of the total combined voting power of all classes of stock of the Company (or any parent or subsidiary) shall be no less than 110 % of the fair market value per share on the date of grant. The option price of an incentive stock option granted to any other employee shall be no less than 100 % of the fair market value per share on the date of grant. At the Company’s annual stockholders meeting in June 2022, the stockholders approved an amendment of the 2000 Stock Plan to increase the number of shares of the Company’s common stock available for issuance by 1,800,000 shares and to extend the term of the 2000 Stock Plan to the date that is ten ( 10 ) years following the stockholders meeting. A total of 6,429,650 shares of common stock have been reserved for issuance under this plan. The plan expires in June 2032 . As of December 31, 2022, 2,171,128 shares of common stock were available for future grant and options to purchase 2,843,416 shares of common stock were outstanding under the 2000 Stock Plan. 2000 Employee Stock Purchase Plan In August 2000, the Company adopted the 2000 Employee Stock Purchase Plan. This purchase plan is implemented by a series of overlapping offering periods of 24 months’ duration, with new offering periods, other than the first offering period, beginning on May 1 and November 1 of each year and ending April 30 and October 31, respectively, two years later. The purchase plan allows eligible employees to purchase common stock through payroll deductions at a price equal to the lower of 85 % of the fair market value of the Company’s common stock at the beginning of each offering period or at the end of each purchase period. The initial offering period commenced on the effectiveness of the Company’s initial public offering. In April 2010, the Board of Directors approved certain amendments to the 2000 Employee Stock Purchase Plan. At the Company’s annual stockholders meeting in June 2010, the stockholders approved the amendment of the 2000 Employee Stock Purchase Plan to: (i) increase the number of shares of our common stock authorized for issuance under the ESPP by 25,000 shares; (ii) extend the term of the ESPP to the date that is ten ( 10 ) years following the stockholders meeting; (iii) provide for six-month consecutive offering periods beginning on November 1, 2010; (iv) revise certain provisions to reflect the final regulations issued under Section 423 of the Code by the Internal Revenue Service; and (v) provide for the cash-out of options outstanding under an offering period in effect prior to the consummation of certain corporate transactions as an alternative to providing for a final purchase under such offering period. In March 2015, the Board of Directors approved certain amendments to the 2000 Employee Stock Purchase Plan. At the Company’s annual stockholders meeting in June 2015, the stockholders approved the amendments of the 2000 Employee Stock Purchase Plan to: (i) increase the number of shares of our common stock authorized for issuance under the ESPP by 35,000 shares; and (ii) extend the term of the ESPP to the date that is ten ( 10 ) years following the stockholders meeting. At each of the Company’s annual stockholders meeting in June 2017 and in June 2020, the stockholders approved amendments of the 2000 Employee Stock Purchase Plan to increase the number of shares our common stock authorized for issuance under the ESPP by 35,000 shares and to re-approve its material terms. The plan expires in June 2030. A total of 325,000 shares of common stock have been reserved for issuance under this plan. As of December 31, 2022, 25,455 shares of common stock were available for future grant and 299,545 shares of common stock have been issued under the 2000 Employee Stock Purchase Plan. As of December 31, 2022, shares of common stock reserved fo r future issuance consisted of the following: December 31, Stock options outstanding 2,843,416 Stock options available for grant 2,171,128 Employee Stock Purchase Plan 25,455 5,039,999 A summary of stock option activity under all stock-based compensation plans is as follows: Number of Weighted Weighted Aggregate Outstanding at December 31, 2021 2,535,943 $ 13.89 4.74 $ 1.7 Options granted 517,851 $ 7.76 Options exercised ( 1,450 ) $ 5.77 Options forfeited ( 95,339 ) $ 12.48 Options expired ( 113,589 ) $ 10.26 Outstanding at December 31, 2022 2,843,416 $ 12.97 4.82 $ — Exercisable at December 31, 2022 2,216,215 $ 13.28 3.79 $ — Vested and expected to vest at 2,843,416 $ 12.97 4.82 $ — The weighted-average grant date fair value of options granted during the years ended December 31, 2022, 2021 and 2020 was $ 7.76 , $ 19.38 , and $ 21.17 per share, respectively. The aggregate intrinsic value in the table above represents the total intrinsic value (i.e., the difference between the Company’s closing stock price on the last trading day of 2022 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their in-the-money options on December 31, 2022. This amount changes based on the fair market value of the Company’s common stock. The total value of options exercised was $ 2,300 , $ 3.1 million and $ 3.6 million for the years ended December 31, 2022, 2021 and 2020, respectively. Expenses for non-employee stock options are recorded over the vesting period of the options, which closely approximates the non-employee’s performance period, with the value determined by the Black-Scholes option valuation method and remeasured over the vesting term. As of December 31, 2022, the Company had three stock-based equity compensation plans, which are described above. The employee stock-based compensation cost that has been included in the statements of operations and comprehensive loss is shown as below (in thousands): Year ended December 31, 2022 2021 2020 Cost of product revenues $ 20 $ 19 $ 13 Research and development 1,215 1,245 981 Selling, general and administrative 1,222 1,424 1,085 $ 2,457 $ 2,688 $ 2,079 Because the Company had a net operating loss carryforward as of December 31, 2022, no excess tax benefits for the tax deductions related to stock-based compensation were recognized in the statement of operations. Additionally, no incremental tax benefits were recognized from stock options exercised during 2021, which would have resulted in a reclassification to reduce net cash provided by operating activities with an offsetting increase in net cash provided by financing activities. Determining Fair Value Valuation and Expense Recognition. The Company estimates the fair value of stock options granted using the Black-Scholes option valuation model. The Company recognizes the expense on a straight-line basis. The expense for options is recognized over the requisite service periods of the awards, which is generally the vesting period. Expected Term. The expected term of options granted represents the period of time that the options are expected to be outstanding. The Company determines the expected life using historical options experience. This develops the expected life by taking the weighted average of the actual life of options exercised and cancelled and assumes that outstanding options are exercised uniformly from the current holding period through the end of the contractual life. Expected Volatility. The Company estimates the volatility of its common stock at the date of grant based on the historical volatility of the Company’s common stock. Risk-Free Rate. The Company bases the risk-free rate that it uses in the Black-Scholes option valuation model on the implied yield in effect at the time of option grant on U.S. Treasury zero-coupon issues with substantially equivalent remaining terms. Dividends. The Company has never paid any cash dividends on its common stock and the Company does not anticipate paying any cash dividends in the foreseeable future. Consequently, the Company uses an expected dividend yield of zero in the Black-Scholes option valuation model. The Company used the following assumptions to estimate the fair value of options granted and shares purchased under its stock plans and employee stock purchase plan for the years ended December 31, 2022, 2021 and 2020: Year ended December 31, 2022 2021 2020 Stock Options Risk-free rate 1.8 - 4.2 % 0.8 - 1.5 % 0.5 - 1.4 % Expected dividend yield — — — Expected term (in years) 7.0 - 7.3 7.0 - 7.8 7.0 - 7.3 Volatility 83 - 86 % 85 - 86 % 84 - 87 % Forfeiture rate (1) 0.0 % 0.0 % 0.0 % (1) The Company accounts for forfeitures as they occur. Year ended December 31, 2022 2021 2020 Employee Stock Purchase Plan Risk-free rate 0.04 - 1.49 % 0.04 % 0.1 % Expected dividend yield — — — Expected term (in years) 0.5 0.5 0.5 Volatility 56 - 80 % 56 - 71 % 78 - 124 % There were 13,575 , 11,367 and 10,179 shares purchased under the Company’s employee stock purchase plan during the years ended December 31, 2022, 2021 and 2020, respectively. Included in the statements of operations and comprehensive loss for the year ended December 31, 2022, 2021 and 2020 was $ 19,000 , $ 57,000 and $ 86,000 , respectively, in stock-based compensation expense related to the recognition of expenses related to shares purchased under the Company’s employee stock purchase plan. As of December 31, 2022, $ 3.7 million of total unrecognized compensation costs related to nonvested stock options is expected to be recognized over the respective vesting terms of each award through 2025. The weighted average term of the unrecognized stock-based compensation expense is 2.1 years. The following table summarizes information about stock options outstanding at December 31, 2022: Options Outstanding Options Exercisable Range of Number of Weighted- Weighted- Number of Weighted- $ 4.00 -$ 5.77 388,747 6.64 $ 5.52 275,052 $ 5.76 $ 5.82 -$ 6.77 71,147 7.74 $ 6.34 40,936 $ 6.09 $ 8.71 -$ 7.77 315,022 8.99 $ 8.71 59,600 $ 8.71 $ 8.80 -$ 8.77 422,420 2.30 $ 10.18 417,574 $ 10.19 $ 11.70 -$ 9.77 486,885 2.79 $ 12.26 483,510 $ 12.26 $ 12.60 -$ 10.77 297,424 3.18 $ 13.16 282,424 $ 13.16 $ 14.00 -$ 11.77 388,454 6.64 $ 18.17 241,237 $ 17.07 $ 20.90 -$ 12.77 380,089 3.56 $ 20.98 331,545 $ 20.97 $ 21.90 -$ 13.77 75,728 6.57 $ 24.32 66,837 $ 24.27 $ 28.00 -$ 14.77 17,500 2.45 $ 28.00 17,500 $ 28.00 $ 4.00 - $ 28.00 2,843,416 4.82 $ 12.97 2,216,215 $ 13.28 The Company received $ 8,000 , $ 3.4 million and $ 3.2 million in cash from option exercises under all stock-based compensation plans for the years ended December 31, 2022, 2021 and 2020, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The Company accounts for income taxes using the liability method under ASC 740, Income Taxes . Under this method, deferred tax assets and liabilities are determined based on temporary differences resulting from the different treatment of items for tax and financial reporting purposes. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. Additionally, the Company must assess the likelihood that deferred tax assets will be recovered as deductions from future taxable income. The Company has provided a full valuation allowance on the Company’s deferred tax assets because the Company believes it is more likely than not that its deferred tax assets will not be realized. The Company evaluates the realizability of its deferred tax assets on a quarterly basis. The Company recorded a deferred tax liability of $ 244,000 on its balance sheet at both December 31, 2022 and 2021 that arose from tax amortization of an indefinite-lived intangible asset. The Company recorded no tax expense in each of the years ended December 31, 2022, 2021 and 2020. The reconciliation of income tax expenses (benefit), at the statutory federal income tax rate of 21 %, to net income tax benefit included in the statements of operations and comprehensive loss for the years ended December 31, 2022, 2021 and 2020 is as follows (in thousands): Year Ended December 31, 2022 2021 2020 U.S. federal taxes benefit at statutory rate $ ( 7,420 ) $ ( 7,616 ) $ ( 122 ) Change in valuation allowance 1,152 2,266 ( 2,022 ) Stock-based compensation 371 641 268 Research and development tax credits ( 1,449 ) ( 954 ) ( 1,132 ) Expiring net operating losses 7,313 5,612 2,991 Other 33 51 17 Total income tax (benefit) provision $ — $ — $ — In 2022, 2021 and 2020, total income tax provision (benefit) expense was zero . Deferred tax assets and liabilities reflect the net tax effects of net operating loss, research and other credit carryforwards, and the temporary differences between the carrying amounts of assets and liabilities for financial reporting and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands): December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards 83,262 90,114 Research and other credits 20,602 19,197 Section 174 R&D capitalization 6,911 — Deferred revenue — 202 Stock-based compensation 2,603 2,741 Other 4,765 4,962 Total deferred tax assets 118,143 117,216 Valuation allowance for deferred tax assets ( 117,639 ) ( 116,358 ) Deferred tax liabilities - right of use asset ( 748 ) ( 1,102 ) Net deferred tax assets and liabilities $ ( 244 ) $ ( 244 ) The Company recognizes deferred tax assets to the extent that the Company believes that these assets are more likely than not to be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If it is determined that the Company would be able to realize deferred tax assets in the future in excess of their net recorded amount, the Company would make an adjustment to the deferred tax asset valuation allowance, which would cause a provision benefit to be recognized. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of tax benefit might change as new information becomes available. Given the Company’s history of operating losses, the net deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $ 1.3 million and $ 2.0 million during 2022 and 2021, and decreased by $ 2.9 million during 2020, respectively. As of December 31, 2022, the Company had net operating loss carryforwards for federal income tax purposes of approximately $ 317.7 million, of which approximately $ 245.2 million will expire in the years 2023 through 2037 , and approximately $ 72.5 million which do not expire, and federal research and development tax credits of approximately $ 18.0 million, which expire at various dates beginning in 2023 through 2042 , if not utilized. As of December 31, 2022, the Company had net operating loss carryforwards for state income tax purposes of approximately $ 243.8 million, which expire in the years 2023 through 2042 , if not utilized, and state research and development tax credits of approximately $ 17.8 million, which do not expire. Utilization of the net operating losses may be subject to a substantial annual limitation due to federal and state ownership change limitations. The annual limitation may result in the expiration of net operating losses before utilization. At December 31, 2022 and December 31, 2021, the Company had unrecognized tax benefits of approximately $ 13.1 million and $ 12.4 million, respectively (none of which, if recognized, would affect the Company’s effective tax rate). The Company does not believe there will be any material changes in its unrecognized tax positions over the next twelve months. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): December 31, 2022 2021 Balance at beginning of the year $ 12,421 $ 10,888 Increase related to prior year tax positions ( 188 ) 911 Increase related to current year tax positions 835 622 Balance at end of the year $ 13,068 $ 12,421 Interest and penalty costs related to unrecognized tax benefits, if any, are classified as a component of interest and other income, net in the Statements of Operations and Comprehensive Loss. The Company did no t recognize any interest and penalties expenses related to unrecognized tax benefits for the years ended December 31, 2022, 2021 and 2020. The Company files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. The Company is subject to U.S. federal and state income tax examination for calendar tax years ending 2002 through 2022 due to unutilized net operating losses and research credits. California Assembly Bill 85 (AB 85) was signed into law in June 2021. The legislation suspended the use of California Net Operating Loss deductions for 2020, 2021, and 2022 for certain taxpayers and imposed a limitation on the use of certain California Tax Credits for 2020, 2021, and 2022. The carryover periods for Net Operating Loss deductions disallowed by this provision were extended. California enacted Senate Bill 113 on February 14, 2022, which removed the net operating loss suspension and limited use of business tax credits for 2022. Senate Bill 113 had no income tax impact as the Company continues to record full valuation allowance against the deferred tax assets due to the cumulative tax losses. Beginning with 2022, the Tax Cuts and Jobs Act eliminated the option to deduct research and development expenditures when incurred under Section 174 and requires taxpayers to capitalize and amortize domestic expenditures over five years and foreign expenditures over fifteen years. Given the lack of current legislative guidance available, the Company has provided for an estimate of their expenditures subject to the Section 174 requirements and established a deferred tax asset, offset by the Company’s 100 % valuation allowance.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2022
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Discontinued Operations	11. Discontinued Operations On December 31, 2020, the C ompany completed the sale of its LACTEL Absorbable Polymers product line to Evonik. Under the terms of the Asset Purchase Agreement, Evonik paid DURECT approximately $ 15.1 million, 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 our LACTEL product line have been excluded from continuing operations and presented as discontinued operations in the accompanying Statements of Operations and Comprehensive Loss for all periods presented. During the twelve months ended December 31, 2020, we 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 and gain from discontinued operations presented 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): Year ended December 31, 2020 Total revenues 4,918 Operating expenses: Cost of product revenues 3,019 Research and development 476 Selling, general and administrative 515 Total costs and expenses 4,010 Income from discontinued operations 908 Other income: Gain on sale of the LACTEL product line 12,845 Net income from discontinued operations $ 13,753 Net income per share Basic and diluted $ 0.69 Weighted-average shares used in computing net income per share basic and diluted Basic and diluted 19,946 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): Years ended December 31, 2020 Depreciation $ 198 Stock-based compensation expense 91 Goodwill 229 Loss on disposal of property and equipment 129 $ 647 Gain on sale of the LACTEL product line $ 12,845 Non-cash items, net $ ( 12,198 )

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events On February 3, 2023 , the Company entered into a securities purchase agreement (the “Purchase Agreement”) with two institutional investors (the “Purchasers”) relating to the purchase and sale of an aggregate of (i) 1,700,000 shares (the “Shares”) of its common stock, par value $ 0.0001 per share (“Common Stock”), (ii) pre-funded warrants to purchase 300,000 shares of Common Stock, and (iii) accompanying common warrants, to purchase an aggregate of 2,000,000 shares of Common Stock in a registered direct offering (the “Offering”). The aggregate gross proceeds to the Company from the Offering were $ 10.0 million before deducting placement agent fees and other estimated offering expenses payable by DURECT and excluding the proce eds, if any, from the exercise of the pre-funded warrants and common warrants issued in the Offering. The aggregate net proceeds to the Company from the Offering were approximately $ 8.8 million after deducting placement agent fees and other estimated offering expenses payable by us. The pre-funded warrants are exercisable immediately foll owing the closing date of the Offering and have an unlimited term and an initial exercise price of $ 0.00001 per share. The common warrants will be immediately exercisable and have a five year term and an initial exercise price of $ 5.00 per share. The combined offering price is $ 5.00 per Share and accompanying common warrant, or in the case of pre-funded warrants, $ 4.99999 per pre-funded warrant and accompanying common warrant. A holder (together with its affiliates) may not exercise any portion of a pre-funded warrant or common warrant to the extent that the holder would own more than 4.99 % (or, at the election of the holder 9.99 %) of DURECT’s outstanding Common Stock immediately after exercise.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Nature Of Operations Policy	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 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.
Basis of Presentation	Basis of Presentation and Use of Estimates The Company’s financial statements have been prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP). The preparation of the accompanying Financial Statements conforms to accounting principles generally accepted in the U.S. which requires management to make judgments, estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosures. On an ongoing basis, management evaluates its estimates including, but not limited to, those related to revenue recognition, the period of performance, identification of performance obligations and evaluation of milestones with respect to our collaborations, the amounts of revenues, recoverability of inventory, certain accrued liabilities including accrued clinical costs, asset retirement obligations, and stock-based compensation. The Company bases its estimates on historical experience and on various other market-specific and other relevant assumptions that the Company believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates. Reverse Stock Split On December 5, 2022, the Company effected a 1-for- 10 reverse stock split of its outstanding common stock. The reverse stock split also affected our outstanding stock options, purchase rights and equity incentive plans and resulted in the shares underlying such instruments being reduced and the exercise price being increased proportionately. For all financial statement periods presented, references to number of shares, net loss per share, stock price and exercise price have been conformed to reflect the effects of the Company’s 1-for- 10 reverse stock split , effective December 5, 2022, unless otherwise specified herein.
Reverse Stock Split	Reverse Stock Split On December 5, 2022, the Company effected a 1-for- 10 reverse stock split of its outstanding common stock. The reverse stock split also affected our outstanding stock options, purchase rights and equity incentive plans and resulted in the shares underlying such instruments being reduced and the exercise price being increased proportionately. For all financial statement periods presented, references to number of shares, net loss per share, stock price and exercise price have been conformed to reflect the effects of the Company’s 1-for- 10 reverse stock split , effective December 5, 2022, unless otherwise specified herein.
Discontinued Operations	Discontinued Operations On December 31, 2020, the Company sold its LACTEL Absorbable Polymer (LACTEL) product line to Evonik. The accompanying financial statements have been recast to reflect the assets, liabilities, revenue and expenses related to the Company’s LACTEL product line as discontinued operations for the years ended December 31, 2020 (see Note 11). The Company believes this format provides comparability with its previously filed financial statements.
Liquidity and Need to Raise Additional Capital Policy	Liquidity and Need to Raise Additional Capital As of December 31, 2022, the Company has an accumulated deficit of $ 561.4 million as well as negative cash flows from operating activities. Presently, the Company does not have sufficient cash resources to meet its plans for the next twelve months following the issuance of these financial statements. The Company will continue to require substantial funds to continue research and development, including clinical trials of its product candidates. These factors raise substantial doubt regarding the Company’s ability to continue as a going concern for a period of one year from the issuance of these financial statements. Management’s plans in order to meet its operating cash flow requirements include seeking additional collaborative agreements for certain of its programs 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 and that the Company will succeed in its future operations. If the Company cannot successfully raise additional capital and implement its strategic development plan, its liquidity, financial condition and business prospects will be materially and adversely affected, and the Company may have to cease operations. As further described in Note 8, the Company reclassified the remaining balance of its term loan to current liabilities from non-current liabilities on the Company’s balance sheet as of December 31, 2022 due to recurring losses, liquidity concerns and a subjective acceleration clause in the Company’s Loan Agreement. These financial statements have been prepared on a going concern basis and do not include any adjustments to the amounts and classification of assets and liabilities that may be necessary in the event the Company can no longer continue as a going concern.
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments The Company considers all highly liquid investments with maturities of 90 days or less from the date of purchase to be cash equivalents. Investments with original maturities of greater than 90 days from the date of purchase but less than one year from the balance sheet date are classified as short-term investments, while investments with maturities in one year or beyond one year from the balance sheet date are classified as long-term investments. Management determines the appropriate classification of its cash equivalents and investment securities at the time of purchase and re-evaluates such determination as of each balance sheet date. Management has classified the Company’s cash equivalents and investments as available-for-sale securities in the accompanying financial statements. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported as a component of accumulated other comprehensive loss. Realized gains and losses are included in interest income. There were no material realized gains or losses in the periods presented. The cost of securities sold is based on the specific identification method. The Company invests in debt instruments of government agencies, corporations, and money market funds with high credit ratings. The Company has established guidelines regarding diversification of its investments and their maturities with the objectives of maintaining safety and liquidity, while maximizing yield. Total cash held in escrow (related to the sale of the LACTEL product line) was $ 15 million as of December 31, 2020; the $ 15 million was released from escrow in January 2021.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to credit risk consist principally of interest-bearing investments and trade receivables. The Company maintains cash, cash equivalents and investments with various major financial institutions. The Company performs periodic evaluations of the relative credit standing of these financial institutions. In addition, the Company performs periodic evaluations of the relative credit quality of its investments. Pharmaceutical companies and academic institutions account for a substantial portion of the Company’s trade receivables. The Company provides credit in the normal course of business to its customers and collateral for these receivables is generally not required. The risk associated with this concentration is limited to a certain extent due to the large number of accounts and their geographic dispersion. The Company monitors the creditworthiness of its customers to which it grants credit terms in the normal course of business. The Company maintains reserves for estimated credit losses and, to date, such losses have been immaterial in all periods presented.
Customer and Product Line Concentrations	Customer and Product Line Concentrations Revenue from the sale of products from the ALZET product line accounted for 31 %, 46 % and 20 % of total revenue for 2022, 2021 and 2020, respectively. Innocoll accounted for 52 % and 37 % of the Company’s total revenue for 2022 and 2021, respectively. Gilead accounted for 76 % of the Company’s total revenue for 2020. Total revenue by geographic region for the years 2022, 2021 and 2020 are as follows (in thousands): Year ended December 31, 2022 2021 2020 United States $ 5,447 $ 5,690 $ 26,894 Europe 11,791 6,630 1,386 Japan 1,488 1,015 1,174 Others 557 642 657 Total $ 19,283 $ 13,977 $ 30,111 Revenue by geography is determined by the location of the customer.
Allowance for Doubtful Accounts	s Allowance for doubtful accounts as of December 31, 2022, 2021 and 2020 were comprised as follows (in thousands): Balance at Additions (Reductions) to allowances Deductions Balance at Allowance for doubtful accounts Year ended December 31, 2022 $ ( 15 ) $ ( 6 ) $ — $ ( 21 ) Year ended December 31, 2021 $ ( 72 ) $ 56 $ 1 $ ( 15 ) Year ended December 31, 2020 $ ( 27 ) $ ( 46 ) $ 1 $ ( 72 )
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 a 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 or little associated cost of goods for these materials. The Company’s inventories consisted of the following (in thousands): December 31, 2022 2021 Raw materials $ 168 $ 143 Work in-process 1,151 712 Finished goods 794 1,015 Total inventories $ 2,113 $ 1,870
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation, which is computed using the straight-line method over the estimated useful lives of the assets, which range from three to five years . Leasehold improvements are amortized using the straight-line method over the estimated useful lives of the assets, or the terms of the related leases, whichever are shorter.
Goodwill	Goodwill Goodwill is periodically assessed and evaluated for impairment. The Company operates in one operating segment and also has only one reporting unit, which is the research, development and manufacturing of pharmaceutical products. The Company assesses the impairment of goodwill at least annually and whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Factors the Company considers important which could trigger an impairment review include the following: • significant decline in our stock price for a prolonged period; • our market capitalization relative to net book value; • new information affecting the commercial value of the asset; • significant underperformance relative to historical or projected future operating results; • significant changes in the manner of our use of the acquired assets or the strategy for the Company’s overall business; and • significant negative industry or economic trends. The Company evaluates goodwill for impairment at least annually. To date, the Company has not recorded any impairment charge related to goodwill.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets, including property and equipment, intangible assets, and other long-term assets, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition is less than its carrying amount. Impairment, if any, is calculated as the amount by which an asset’s carrying value exceeds its fair value, typically using discounted cash flows to determine fair value. Through December 31, 2022, there have been no material impairment losses.
Leases	Leases ASC 842 requires the Company to recognize an operating lease right-of-use asset and corresponding operating lease liability for the Company’s leased properties. The Company’s operating lease right-of-use assets and liabilities are recognized under ASC 842 based on the present value of lease payments over the remaining lease term at the lease commencement date. In determining the net present value of lease payments, we estimate the incremental borrowing rate based on the information available, including remaining lease term. As of December 31, 2022, the weighted-average remaining lease term was 0.99 years for the Company’s leased properties.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for share-based payments using a fair-value based method for costs related to all share-based payments, including stock options and stock issued under the Company’s employee stock purchase plan (ESPP). The Company estimates the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company recognizes compensation costs on a straight-line basis over the requisite service period and accounts for forfeitures as they occur. See Note 9 for further information regarding stock-based compensation.
Revenue Recognition	Revenue Recognition Product Revenue, Net The Company manufacture and sell ALZET osmotic pumps used in laboratory research, and manufacture and sell certain excipients used by pharmaceutical companies as raw materials in certain of their products, including POSIMIR, an animal health product and Methydur. 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: The Company generally offers customers a limited right of return for products that have been purchased. The Company estimates the amount of its product sales that are probable of being 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 primarily using its historical sales information. The Company expects 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 or products 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, intellectual property and commercial milestone payments; payments for manufacturing supply services the Company provides itself or 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 and earn-out revenues, 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. For arrangements that are determined to include multiple performance obligations, the Company must develop assumptions that require judgment to determine the estimated stand-alone selling price for each performance obligation identified. These assumptions 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 the transaction price 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 performance obligations comprised of licenses that are bundled with other promises, the Company utilizes its 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 Company applies an appropriate method of measuring progress for purposes of recognizing related revenues from the allocated transaction price. For performance obligations recognized over time, the Company evaluates the measure of progress each reporting period and recognizes revenues on a cumulative catch-up basis as collaborative research and development revenues. 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. Manufacturing Supply Services: Arrangements that include a promise for future supply of raw materials or 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 and allocated a portion of the transaction price based on the estimated standalone selling price of the material right. If the Company is entitled to additional payments when the customer exercises these options, the deferred transaction price and any additional payments are recorded in collaborative research and development revenue when the customer obtains control of the goods. Royalties and Earn-outs: For arrangements that include sales-based royalties or earn-outs, including milestone payments based on first commercial sale or 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 revenues from any of the Company’s agreements. Research and development services: Revenue from research and development services that are determined to represent a distinct performance obligation with the Company’s third-party collaborators is recognized over time as the related research and development services are performed using an appropriate method of measuring progress. The Company evaluates the measure of progress each reporting period and recognizes revenue on a cumulative catch-up basis, as collaborative research and development revenue. Research and development expenses under the collaborative research and development agreements generally approximate or exceed the revenue recognized under such agreements over the term of the respective agreements. Deferred revenue may result when the Company does not expend the required level of effort during a specific period in comparison to funds received under the respective agreement. 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.
Prepaid and Accrued Clinical Costs	Prepaid and Accrued Clinica l Costs The Company incurs significant costs associated with third party consultants and organizations for pre-clinical studies, clinical trials, contract research, 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. Estimates are determined each reporting period by reviewing the terms and conditions of the underlying contracts, reviewing open purchase orders and by having detailed discussions with internal clinical personnel and third-party service providers as to the nature and status of the services performed in relation to amounts billed. The costs for unbilled services are estimated by applying the rates and fees applicable in the underlying contracts. If these good faith estimates are inac curate, actual expenses incurred could materially differ from these estimates.
Prepaid and Accrued Manufacturing Costs	Prepaid and Accrued Manufacturing Costs The Company incurs significant costs associated with third party consultants and organizations for manufacturing, validation, testing 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. Estimates are determined each reporting period by reviewing the terms and conditions of the underlying contracts, reviewing open purchase orders and by having detailed discussions with internal personnel and third-party service providers as to the nature and status of the services performed in relation to amounts billed. The costs for unbilled services are estimated by applying the rates and fees applicable in the underlying contracts. If these good faith estimates are inaccurate, actual expenses incurred could materially differ from these estimates.
Research and Development Expenses	Research and Development Expenses 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, research and development expenses incurred that are reimbursed by the Company’s partners are recorded as collaborative research and development revenue.
Comprehensive Loss	Comprehensive Loss 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 Operations and Comprehensive Loss.
Segment Reporting	Segment Reporting The Company operates in one operating segment, which is the research, development and manufacturing of pharmaceutical products.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding. Diluted net loss 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 per share were as follows (in thousands except per share amounts): Year Ended December 31, 2022 2021 2020 Numerators: Net loss $ ( 35,333 ) $ ( 36,265 ) $ ( 582 ) Denominators: Weighted average shares used to compute basic 22,777 22,505 19,946 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute diluted 22,777 22,505 19,946 Net loss per share: Basic $ ( 1.55 ) $ ( 1.61 ) $ ( 0.03 ) Diluted $ ( 1.55 ) $ ( 1.61 ) $ ( 0.03 ) The computation of diluted net loss per share for 2022, 2021 and 2020 excludes the impact of options to purchase 2.8 million, 834,000 and 752,000 shares of common stock outstanding at December 31, 2022, 2021 and 2020, respectively, as such impact would be antidilutive.
Shipping and Handling	Shipping and Handling Costs related to shipping and handling are included in cost of revenues for all periods presented.
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 adopted the standard on January 1, 2023 and the adoption did not have a material effect on the financial statements. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. In response to concerns about structural risks of the cessation of London Interbank Offered Rate (LIBOR), the amendments in this ASU provide optional guidance for a limited time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendments in this ASU provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU apply only to contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022. The amendments in this ASU are elective and are effective for all entities as of March 12, 2020 through December 31, 2022. The adoption of the standard did not have a material effect on the financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Total Revenue by Geographic Region	Total revenue by geographic region for the years 2022, 2021 and 2020 are as follows (in thousands): Year ended December 31, 2022 2021 2020 United States $ 5,447 $ 5,690 $ 26,894 Europe 11,791 6,630 1,386 Japan 1,488 1,015 1,174 Others 557 642 657 Total $ 19,283 $ 13,977 $ 30,111
Summery of Allowance for Doubtful Accounts	Allowance for doubtful accounts as of December 31, 2022, 2021 and 2020 were comprised as follows (in thousands): Balance at Additions (Reductions) to allowances Deductions Balance at Allowance for doubtful accounts Year ended December 31, 2022 $ ( 15 ) $ ( 6 ) $ — $ ( 21 ) Year ended December 31, 2021 $ ( 72 ) $ 56 $ 1 $ ( 15 ) Year ended December 31, 2020 $ ( 27 ) $ ( 46 ) $ 1 $ ( 72 )
Summary of Components of Inventories	The Company’s inventories consisted of the following (in thousands): December 31, 2022 2021 Raw materials $ 168 $ 143 Work in-process 1,151 712 Finished goods 794 1,015 Total inventories $ 2,113 $ 1,870
Summary of Numerators and Denominators in Calculation of Basic and Diluted Net Income (Loss) per Share	The numerators and denominators in the calculation of basic and diluted net loss per share were as follows (in thousands except per share amounts): Year Ended December 31, 2022 2021 2020 Numerators: Net loss $ ( 35,333 ) $ ( 36,265 ) $ ( 582 ) Denominators: Weighted average shares used to compute basic 22,777 22,505 19,946 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute diluted 22,777 22,505 19,946 Net loss per share: Basic $ ( 1.55 ) $ ( 1.61 ) $ ( 0.03 ) Diluted $ ( 1.55 ) $ ( 1.61 ) $ ( 0.03 )

Strategic Agreements (Tables)

Strategic Agreements (Tables)	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators	The collaborative research and development and other revenue associated with the Company’s major third-party collaborators are as follows (in thousands): Year ended December 31, 2022 2021 2020 Collaborator/Counterparty Innocoll (1) $ 10,015 $ 4,100 $ — Gilead (2) — — 22,879 Other (3) 3,189 2,231 1,062 Total collaborative research and development and other revenue $ 13,204 $ 6,331 $ 23,941 (1) The Company signed a license agreement with Innocoll on December 21, 2021, pursuant to which Innocoll agreed to pay a nonrefundable upfront license fee of $ 4.0 million and $ 1.3 million primarily for the sale of manufacturing supplies and excipients. In December 2021, upon the transfer of control of the license, the manufacturing supplies and excipients, and equipment to Innocoll, the Company recognized $ 4.1 million as collaborative research and development and other revenue, $ 1.1 million as product revenue, and a reduction of $ 0.1 million in net equipment. In the twelve months ended December 31, 2022, the Company recognized $ 8.0 million of patent milestone revenue and $ 2.0 million of first commercial sale milestone revenue under the license agreement with Innocoll. (2) The Company signed a license agreement with Gilead on July 19, 2019. Amounts related to recognition of upfront fees and milestone payments were zero , zero and $ 22.7 million for the twelve months ended December 31, 2022, 2021 and 2020, respectively. The Company received a nonrefundable upfront license fee and a milestone payment totaling $ 35.0 million in 2019 which was being recognized as revenue as its obligation was being satisfied using the cost-to-cost input method. In June 2020, the Company received notice that Gilead was terminating the License Agreement and a related R&D agreement between Gilead and the Company. 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. Amounts recognized as revenue during the twelve months ended December 31, 2020 also included the Company’s reimbursable collaborative research and development services performed under its agreement with Gilead. (3) Includes: (a) amounts related to earn-out revenue from Indivior UK Limited (Indivior) with respect to PER SERIS net sales; (b) royalty revenue from OP Pharma with respect to Methydur net sales; and (c) revenue from other agreements, including research and development activities funded by our collaborators and recognition of deferred revenue.

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements of Assets and Liabilities	The following table sets forth the fair value of the Company’s financial assets that were measured at fair value on a recurring basis as of December 31, 2022 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 633 $ — $ — $ 633 Certificates of deposit — 150 — 150 Commercial paper — 40,465 — 40,465 Total $ 633 $ 40,615 $ — $ 41,248 The following table sets forth the fair value of our financial assets that were measured at fair value on a recurring basis as of December 31, 2021 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 2,089 $ — $ — $ 2,089 Certificates of deposit — 150 — 150 Commercial paper — 62,495 — 62,495 U.S. Government agencies — 1,293 — 1,293 Total $ 2,089 $ 63,938 $ — $ 66,027
Summary of Money Market Funds and Available-for-Sale Securities	The following is a summary of available-for-sale securities as of December 31, 2022 and 2021 (in thousands): December 31, 2022 Amortized Unrealized Unrealized Estimated Money market funds $ 633 $ — $ — $ 633 Certificates of deposit 150 — — 150 Commercial paper 40,478 — ( 13 ) 40,465 $ 41,261 $ — $ ( 13 ) $ 41,248 Reported as: Cash and cash equivalents $ 41,111 $ — $ ( 13 ) $ 41,098 Long-term restricted investments 150 — — 150 $ 41,261 $ — $ ( 13 ) $ 41,248 December 31, 2021 Amortized Unrealized Unrealized Estimated Money market funds $ 2,089 $ — $ — $ 2,089 Certificates of deposit 150 — — 150 Commercial paper 62,505 — ( 10 ) 62,495 Corporate debt 1,293 — — 1,293 $ 66,037 $ — $ ( 10 ) $ 66,027 Reported as: Cash and cash equivalents $ 45,913 $ — $ ( 2 ) $ 45,911 Short-term investments 19,974 — ( 8 ) 19,966 Long-term restricted investments 150 — — 150 $ 66,037 $ — $ ( 10 ) $ 66,027
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 December 31, 2022, by contractual maturity (in thousands): December 31, 2022 Amortized Estimated Mature in one year or less $ 40,478 $ 40,465 Mature after one year through five years 150 150 $ 40,628 $ 40,615

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and equipment consist of the following (in thousands): December 31, 2022 2021 Equipment $ 10,791 $ 10,696 Leasehold improvements 8,490 8,474 19,281 19,170 Less accumulated depreciation and amortization ( 19,093 ) ( 18,943 ) Property and equipment, net $ 188 $ 227

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Summary of Lease Arrangements of Company Facilities	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 (with an option to renew for an additional five years )
Schedule of future operating lease minimum payments	Future minimum payments under these noncancelable leases are as follows (in thousands): Year ending December 31, Operating 2023 1,970 2024 275 2,245 Less present value adjustment ( 153 ) Operating lease liabilities recognized $ 2,092

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of accrued liabilities	Accrued liabilities as of December 31, 2022 and 2021 were comprised as follows (in thousands): December 31, 2022 2021 Accrued compensation and benefits $ 3,970 $ 4,099 Accrued clinical costs 1,966 97 Accrued contract research and manufacturing cost 861 757 Others 1,099 1,846 Total $ 7,896 $ 6,799

Term Loan (Tables)

Term Loan (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Future Maturities Due under Term Loan	The fair value of the term loan approximates the carrying value. Future maturities due under the term loan as of December 31, 2022, are as follows (in thousands): 2023 $ 5,714 2024 8,571 2025 7,715 Total minimum payments 22,000 Less unamortized debt discount and accrued final payment ( 830 ) Carrying value of term loan, net 21,170

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Summary of Shares of Common Stock Reserved for Future Issuance	As of December 31, 2022, shares of common stock reserved fo r future issuance consisted of the following: December 31, Stock options outstanding 2,843,416 Stock options available for grant 2,171,128 Employee Stock Purchase Plan 25,455 5,039,999
Summary of Stock Option Activity under all Stock-Based Compensation Plans	A summary of stock option activity under all stock-based compensation plans is as follows: Number of Weighted Weighted Aggregate Outstanding at December 31, 2021 2,535,943 $ 13.89 4.74 $ 1.7 Options granted 517,851 $ 7.76 Options exercised ( 1,450 ) $ 5.77 Options forfeited ( 95,339 ) $ 12.48 Options expired ( 113,589 ) $ 10.26 Outstanding at December 31, 2022 2,843,416 $ 12.97 4.82 $ — Exercisable at December 31, 2022 2,216,215 $ 13.28 3.79 $ — Vested and expected to vest at 2,843,416 $ 12.97 4.82 $ —
Summary of Employee Stock-Based Compensation Cost that has been Included in Statements of Operations and Comprehensive Loss	As of December 31, 2022, the Company had three stock-based equity compensation plans, which are described above. The employee stock-based compensation cost that has been included in the statements of operations and comprehensive loss is shown as below (in thousands): Year ended December 31, 2022 2021 2020 Cost of product revenues $ 20 $ 19 $ 13 Research and development 1,215 1,245 981 Selling, general and administrative 1,222 1,424 1,085 $ 2,457 $ 2,688 $ 2,079
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 options granted and shares purchased under its stock plans and employee stock purchase plan for the years ended December 31, 2022, 2021 and 2020: Year ended December 31, 2022 2021 2020 Stock Options Risk-free rate 1.8 - 4.2 % 0.8 - 1.5 % 0.5 - 1.4 % Expected dividend yield — — — Expected term (in years) 7.0 - 7.3 7.0 - 7.8 7.0 - 7.3 Volatility 83 - 86 % 85 - 86 % 84 - 87 % Forfeiture rate (1) 0.0 % 0.0 % 0.0 % (1) The Company accounts for forfeitures as they occur. Year ended December 31, 2022 2021 2020 Employee Stock Purchase Plan Risk-free rate 0.04 - 1.49 % 0.04 % 0.1 % Expected dividend yield — — — Expected term (in years) 0.5 0.5 0.5 Volatility 56 - 80 % 56 - 71 % 78 - 124 %
Summary of Stock Options Outstanding	The following table summarizes information about stock options outstanding at December 31, 2022: Options Outstanding Options Exercisable Range of Number of Weighted- Weighted- Number of Weighted- $ 4.00 -$ 5.77 388,747 6.64 $ 5.52 275,052 $ 5.76 $ 5.82 -$ 6.77 71,147 7.74 $ 6.34 40,936 $ 6.09 $ 8.71 -$ 7.77 315,022 8.99 $ 8.71 59,600 $ 8.71 $ 8.80 -$ 8.77 422,420 2.30 $ 10.18 417,574 $ 10.19 $ 11.70 -$ 9.77 486,885 2.79 $ 12.26 483,510 $ 12.26 $ 12.60 -$ 10.77 297,424 3.18 $ 13.16 282,424 $ 13.16 $ 14.00 -$ 11.77 388,454 6.64 $ 18.17 241,237 $ 17.07 $ 20.90 -$ 12.77 380,089 3.56 $ 20.98 331,545 $ 20.97 $ 21.90 -$ 13.77 75,728 6.57 $ 24.32 66,837 $ 24.27 $ 28.00 -$ 14.77 17,500 2.45 $ 28.00 17,500 $ 28.00 $ 4.00 - $ 28.00 2,843,416 4.82 $ 12.97 2,216,215 $ 13.28

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Reconciliation of Income Tax Expenses (Benefit)	The reconciliation of income tax expenses (benefit), at the statutory federal income tax rate of 21 %, to net income tax benefit included in the statements of operations and comprehensive loss for the years ended December 31, 2022, 2021 and 2020 is as follows (in thousands): Year Ended December 31, 2022 2021 2020 U.S. federal taxes benefit at statutory rate $ ( 7,420 ) $ ( 7,616 ) $ ( 122 ) Change in valuation allowance 1,152 2,266 ( 2,022 ) Stock-based compensation 371 641 268 Research and development tax credits ( 1,449 ) ( 954 ) ( 1,132 ) Expiring net operating losses 7,313 5,612 2,991 Other 33 51 17 Total income tax (benefit) provision $ — $ — $ —
Summary of Components of Company's Deferred Tax Assets	Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands): December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards 83,262 90,114 Research and other credits 20,602 19,197 Section 174 R&D capitalization 6,911 — Deferred revenue — 202 Stock-based compensation 2,603 2,741 Other 4,765 4,962 Total deferred tax assets 118,143 117,216 Valuation allowance for deferred tax assets ( 117,639 ) ( 116,358 ) Deferred tax liabilities - right of use asset ( 748 ) ( 1,102 ) Net deferred tax assets and liabilities $ ( 244 ) $ ( 244 )
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): December 31, 2022 2021 Balance at beginning of the year $ 12,421 $ 10,888 Increase related to prior year tax positions ( 188 ) 911 Increase related to current year tax positions 835 622 Balance at end of the year $ 13,068 $ 12,421

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2022
Disposal Group, Including 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): Year ended December 31, 2020 Total revenues 4,918 Operating expenses: Cost of product revenues 3,019 Research and development 476 Selling, general and administrative 515 Total costs and expenses 4,010 Income from discontinued operations 908 Other income: Gain on sale of the LACTEL product line 12,845 Net income from discontinued operations $ 13,753 Net income per share Basic and diluted $ 0.69 Weighted-average shares used in computing net income per share basic and diluted Basic and diluted 19,946
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): Years ended December 31, 2020 Depreciation $ 198 Stock-based compensation expense 91 Goodwill 229 Loss on disposal of property and equipment 129 $ 647 Gain on sale of the LACTEL product line $ 12,845 Non-cash items, net $ ( 12,198 )

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)		12 Months Ended
	Dec. 05, 2022	Dec. 31, 2022 USD ($) Segment shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Jan. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit		$ (561,382,000)	$ (526,049,000)
Date of incorporation		Feb. 06, 1998
Reverse stock split ratio	10
Description of reverse stock split	1-for-10 reverse stock split	1-for-10 reverse stock split of its outstanding common stock.
Substantial Doubt about Going Concern, within One Year [true false]		true
Accumulated deficit		$ 561,382,000	526,049,000
Highly liquid investments maturity period		90 days or less
Long term investments maturity period description minimum		one year or beyond
Realized investment gains losses		$ 0	$ 0
Amount released from escrow					$ 15,000,000
Number of operating segments | Segment		1
Number of reportable segments | Segment		1
Impairment of long lived assets held for use		$ 0
Operating lease weighted average remaining lease term1		11 months 26 days	1 year 11 months 26 days
Antidilutive securities excluded from computation of earnings per share amount | shares		2,800,000	834,000	752,000
Sales Revenue Net [Member] | Customer Concentration Risk [Member] | Gilead [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted in Company's total revenue				76%
Sales Revenue Net [Member] | Customer Concentration Risk [Member] | Indivior [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted in Company's total revenue		52%	37%
LACTEL Product Line [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash held in escrow				$ 15,000,000
ALZET Product Line [Member] | Sales Revenue Net [Member] | Product Concentration Risk [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted in Company's total revenue		31%	46%	20%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Short term investment maturity period		90 days
Property plant and equipment useful life		3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Short term investment maturity period		1 year
Property plant and equipment useful life		5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Total Revenue by Geographic Region (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 19,283	$ 13,977	$ 30,111
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,447	5,690	26,894
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	11,791	6,630	1,386
Japan
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	1,488	1,015	1,174
Other Foreign Countries
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 557	$ 642	$ 657

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summery of Allowance for Doubtful Accounts (Detail) - Allowance for doubtful accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the year	$ (15)	$ (72)	$ (27)
Additions (Reductions) to allowances	(6)	56	(46)
Deductions		1	1
Balance at end of the year	$ (21)	$ (15)	$ (72)

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Components of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Raw materials	$ 168	$ 143
Work in-process	1,151	712
Finished goods	794	1,015
Total inventories	$ 2,113	$ 1,870

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Summary of Numerators and Denominators in Calculation of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerators:
Net loss	$ (35,333)	$ (36,265)	$ (582)
Denominators:
Weighted average shares used to compute basic net loss per share	22,777	22,505	19,946
Effect of dilutive securities:
Weighted average shares used to compute diluted net loss per share	22,777	22,505	19,946
Net loss per share:
Net income per share, Basic	$ (1.55)	$ (1.61)	$ (0.03)
Net income per share, diluted	$ (1.55)	$ (1.61)	$ (0.03)

Strategic Agreements - Summary

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators (Detail) - USD ($)			12 Months Ended
		Jul. 19, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue			$ 19,283,000	$ 13,977,000	$ 30,111,000
Collaborative Research and Development and Other Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue			13,204,000	6,331,000	23,941,000
Agreement With Innocoll
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue			10,000,000
Agreement With Innocoll | 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]		10,015,000	4,100,000
Agreement with Gilead [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		$ 25,000,000	0	0	22,700,000
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	[2]				22,879,000
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	[3]		$ 3,189,000	$ 2,231,000	$ 1,062,000
[1] The Company signed a license agreement with Innocoll on December 21, 2021, pursuant to which Innocoll agreed to pay a nonrefundable upfront license fee of $ 4.0 million and $ 1.3 million primarily for the sale of manufacturing supplies and excipients. In December 2021, upon the transfer of control of the license, the manufacturing supplies and excipients, and equipment to Innocoll, the Company recognized $ 4.1 million as collaborative research and development and other revenue, $ 1.1 million as product revenue, and a reduction of $ 0.1 million in net equipment. In the twelve months ended December 31, 2022, the Company recognized $ 8.0 million of patent milestone revenue and $ 2.0 million of first commercial sale milestone revenue under the license agreement with Innocoll. The Company signed a license agreement with Gilead on July 19, 2019. Amounts related to recognition of upfront fees and milestone payments were zero , zero and $ 22.7 million for the twelve months ended December 31, 2022, 2021 and 2020, respectively. The Company received a nonrefundable upfront license fee and a milestone payment totaling $ 35.0 million in 2019 which was being recognized as revenue as its obligation was being satisfied using the cost-to-cost input method. In June 2020, the Company received notice that Gilead was terminating the License Agreement and a related R&D agreement between Gilead and the Company. 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. Amounts recognized as revenue during the twelve months ended December 31, 2020 also included the Company’s reimbursable collaborative research and development services performed under its agreement with Gilead. Includes: (a) amounts related to earn-out revenue from Indivior UK Limited (Indivior) with respect to PER SERIS net sales; (b) royalty revenue from OP Pharma with respect to Methydur net sales; and (c) revenue from other agreements, including research and development activities funded by our collaborators and recognition of deferred revenue.

Strategic Agreements - Summar_2

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators (Parenthetical) (Detail) - USD ($)		12 Months Ended
	Jul. 19, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		$ 19,283,000	$ 13,977,000	$ 30,111,000
Reduction in net equipment			100,000
Other Research And Development Revenue			4,100,000
Sales-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned		110,000,000
Product Revenue, Net [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		6,079,000	7,646,000	6,170,000
Agreement with Gilead [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 25,000,000	0	0	$ 22,700,000
Agreement with Gilead [Member] | License Fees [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned					$ 35,000,000
Agreements With Other Collaborators or Counterparties [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount from sale of manufacturing supplies and excipients.			1,300,000
Reduction in net equipment			100,000
Agreements With Other Collaborators or Counterparties [Member] | License Fees [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned			4,000,000
Agreements With Other Collaborators or Counterparties [Member] | Product Revenue, Net [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues			$ 1,100,000
Agreement With Innocoll
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		10,000,000
Agreement With Innocoll | Patent Based Milestone [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		8,000,000
Agreement With Innocoll | Sales-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		2,000,000
Agreement With Innocoll | License Fees [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues		$ 4,000,000

Strategic Agreements - Addition

Strategic Agreements - Additional Information (Detail) - USD ($)	1 Months Ended			12 Months Ended
	Jan. 31, 2023	Sep. 30, 2022	Aug. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues				$ 19,283,000	$ 13,977,000	$ 30,111,000
Reduction in net equipment					100,000
Agreement With Innocoll
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues				10,000,000
Performance Milestone Payments Based On Successful Development				1,300,000
Additional Milestone Payment		$ 122,000,000
Upfront Fee					4,000,000
Agreement With Innocoll | Accounts Receivable
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Receivables from Customers					5,300,000
Agreement With Innocoll | Reimbursement Expense [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront Fee					$ 1,200,000
License Fees [Member] | Agreement With Innocoll
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues				4,000,000
Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned				122,000,000
Regulatory approvals [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development-based milestones				10,000,000
Subsequent Event [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 2,000,000
Development-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned				10,000,000
Sales-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned				110,000,000
Sales-Based Milestones [Member] | Agreement With Innocoll
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues				2,000,000
Milestone payment		$ 2,000,000
Patent Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned				$ 2,000,000
Patent Based Milestones [Member] | Agreement With Innocoll
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment			$ 8,000,000

Strategic Agreements - Agreemen

Strategic Agreements - Agreement with Gilead Sciences, Inc - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
	Jul. 19, 2019	Oct. 31, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues			$ 19,283,000	$ 13,977,000	$ 30,111,000
Deferred Revenue						$ 4,800,000
Upfront, Development, Regulatory and Sales-Based Milestones [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Performance Milestone Payments Based On Successful Development						35,000,000
Collaborative Research and Development and Other Revenue [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue recognized						$ 12,300,000
Agreement with Gilead [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues	$ 25,000,000		$ 0	$ 0	$ 22,700,000
Amount related to the milestone payment earned		$ 10,000,000

Strategic Agreements - Patent P

Strategic Agreements - Patent Purchase Agreement with Indivior - Additional Information (Detail) $ in Millions	1 Months Ended
	Sep. 30, 2017 USD ($)
Accounting Policies [Abstract]
Non Refundable Upfront Payment Received	$ 17.5

Financial Instruments - Fair Va

Financial Instruments - Fair Value Measurements of Assets (Detail) - Fair Value on Recurring Basis [Member] - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 41,248	$ 66,027
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	633	2,089
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	40,615	63,938
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	633	2,089
Money market funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	633	2,089
Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	150	150
Certificates of deposit [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	150	150
Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	40,465	62,495
Commercial paper [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 40,465	62,495
U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total		1,293
U.S. Government agencies [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total		$ 1,293

Financial Instruments - Summary

Financial Instruments - Summary of Money Market Funds and Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 41,261	$ 66,037
Unrealized Loss	(13)	(10)
Estimated Fair Value	41,248	66,027
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	633	2,089
Estimated Fair Value	633	2,089
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	40,478	62,505
Unrealized Loss	(13)	(10)
Estimated Fair Value	40,465	62,495
Corporate Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,293
Estimated Fair Value		1,293
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	41,111	45,913
Unrealized Loss	(13)	(2)
Estimated Fair Value	41,098	45,911
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		19,974
Unrealized Loss		(8)
Estimated Fair Value		19,966
Long Term Restricted Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	150	150
Estimated Fair Value	$ 150	$ 150

Financial Instruments - Summa_2

Financial Instruments - Summary of Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Investments, Debt and Equity Securities [Abstract]
Mature in one year or less, Amortized Cost	$ 40,478
Mature after one year through five years, Amortized Cost	150
Amortized Cost	40,628
Mature in one year or less, Estimated Fair Value	40,465
Mature after one year through five years, Estimated Fair Value	150
Estimated Fair Value	$ 40,615

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail)	Dec. 31, 2022 USD ($)
Investments, Debt and Equity Securities [Abstract]
Unrealized loss of securities	$ 0

Property and Equipment - Proper

Property and Equipment - Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 19,281	$ 19,170
Less accumulated depreciation and amortization	(19,093)	(18,943)
Property and equipment, net	188	227
Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	10,791	10,696
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 8,490	$ 8,474

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 150,000	$ 132,000	$ 297,000
Restoration cost	$ 607,000	$ 638,000

Restricted Investments - Additi

Restricted Investments - Additional Information (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Restricted Investments [Line Items]
Restricted investments in connection with deposits on letters of credit	$ 150,000	$ 150,000
California [Member]
Restricted Investments [Line Items]
Restricted investments in connection with deposits on letters of credit	$ 150,000	$ 150,000

Commitments - Summary of Lease

Commitments - Summary of Lease Arrangements of Company Facilities (Detail)	12 Months Ended
	Dec. 31, 2022 ft²
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
Lease Expiration Term	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
Lease Expiration Term	Lease expires 2024 (with an option to renew for an additional five years)
Vacaville, CA [Member] | Manufacturing [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet	24,634
Lease Expiration Term	Lease expires 2023 (with an option to renew for an additional five years)
Lease expiration year	2023
Lease renewal term	5 years

Commitments - Additional Inform

Commitments - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Rent expenses of operating leases	$ 1.9	$ 1.9	$ 1.9
Operating lease weighted average remaining lease term1	11 months 26 days	1 year 11 months 26 days
Incremental Borrowing Rate	13.80%

Commitments - Schedule of Futur

Commitments - Schedule of Future Operating Lease Minimum Payments (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Leases [Abstract]
2023	$ 1,970
2024	275
Total operating leases future minimum payments	2,245
Less present value adjustment	(153)
Operating lease liabilities recognized	$ 2,092

Accrued Liabilities (Details) -

Accrued Liabilities (Details) - Schedule of accrued liabilities - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Accrued Liabilities [Abstract]
Accrued compensation and benefits	$ 3,970	$ 4,099
Accrued clinical costs	1,966	97
Accrued contract research and manufacturing cost	861	757
Others	1,099	1,846
Total	$ 7,896	$ 6,799

Term Loan - Additional Informat

Term Loan - Additional Information (Detail) - Oxford Finance LLC Term Loan [Member] - USD ($)	1 Months Ended				2 Months Ended
	Dec. 31, 2019	Nov. 30, 2018	Feb. 28, 2018	Jul. 31, 2016	Mar. 01, 2021	Dec. 31, 2022
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. 01, 2023
Term loan, maturity date				Sep. 01, 2025
Interest rate on term loan				7.95%		11.45%
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%
Debt offering/issuance costs				$ 2,000,000
Loan modification fee	$ 825,000	$ 900,000	$ 100,000		$ 712,500
Minimum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee				0.75%
Maximum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee				2.50%

Term Loan - Schedule of Future

Term Loan - Schedule of Future Maturities Due under Term Loan (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Future maturities and interest payments under the term loan:
2023	$ 5,714
2024	8,571
2025	7,715
Total minimum payments	22,000
Less unamortized debt discount and accrued final payment	(830)
Carrying value of term loan, net	21,170
Less current portion of long-term debt, net	$ 21,170
Long-term debt, net		$ 20,632

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock - Additional Information (Detail)			1 Months Ended		12 Months Ended
	Dec. 05, 2022	Jun. 20, 2019 USD ($) $ / shares shares	Feb. 28, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares	Jul. 31, 2021 USD ($)	Oct. 31, 2018 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock number of shares issued in transaction | shares		2,900,000
Sale of stock price per share | $ / shares		$ 5.20
Gross proceeds from sale of common stock		$ 15,100,000
Net proceeds from issuances of common stock in connection with equity financings					$ 25,000	$ 47,660,000	$ 12,283,000
Reverse stock split ratio	10
Description of reverse stock split	1-for-10 reverse stock split				1-for-10 reverse stock split of its outstanding common stock.
October Two Thousand Eighteen Registration Statement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock weighted average price | $ / shares				$ 23.90		$ 26		$ 15.50
Net proceeds from issuances of common stock in connection with equity financings				$ 12,300,000		$ 2,400,000		$ 3,500,000
Issuance of common stock upon equity financings, net of issuance cost, shares | shares				530,800		95,000		234,982
2015 Sales Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available-for-sale Securities									$ 75,000,000
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered										$ 175,000,000
Maximum [Member] | October Two Thousand Eighteen Registration Statement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available-for-sale Securities									$ 250,000,000
Cantor Fitzgerald Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock number of shares issued in transaction | shares			2,036,458
Sale of stock price per share | $ / shares			$ 22.39
Gross proceeds from sale of common stock			$ 45,400,000
Net proceeds from issuances of common stock in connection with equity financings			45,600,000
Common stock issuance costs			$ 195,000
Cantor Fitzgerald Co [Member] | Maximum [Member] | Controlled Equity Offering Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered										$ 75,000,000

Stockholders' Equity - 2000 Sto

Stockholders' Equity - 2000 Stock Plan (Incentive Stock Plan) - Additional Information (Detail) - shares	1 Months Ended							3 Months Ended	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2016	Jun. 30, 2014	Apr. 30, 2013	Jun. 30, 2011	Mar. 31, 2000	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved common stock for issuance									5,039,999
Options exercised, shares									517,851
Shares available for future grant									2,171,128
Common stock outstanding									2,843,416	2,535,943
2000 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum expiration term of stock appreciation rights									10 years
Extended term of stock plan to the date	10 years	10 years							10 years
Sale of common stock during period	1,800,000		750,000	500,000	400,000		550,000
Reserved common stock for issuance									6,429,650
Plan expiry date									Jun. 30, 2032
Options exercised, shares						7,000
Option plan vesting period						10 years
Options granted with different vesting terms									5 years
Minimum percentage of total combined voting power of stock									10%
Minimum exercise price as percentage of fair market value to holder of more than 10% voting power									110%
Minimum exercise price as percentage of fair market value to holder of 10% or less voting power									100%
Shares available for future grant									2,171,128
Common stock outstanding									2,843,416
2000 Stock Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercisable period						1 year
2000 Stock Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercisable period						2 years
2000 Stock Plan [Member] | Non-employee director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised, shares								3,000

Stockholders' Equity - 2000 Emp

Stockholders' Equity - 2000 Employee Stock Purchase Plan - Additional Information (Detail) - USD ($)	1 Months Ended			12 Months Ended
	Jun. 30, 2020	Mar. 31, 2015	Apr. 30, 2010	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued				22,785,000	22,768,000
Weighted-average grant date fair value of options granted				$ 7.76	$ 19.38	$ 21.17
Shares available for future grant				2,171,128
Excess tax benefits recognized for tax deductions on stock based compensation				$ 0
Incremental tax benefits recognized from stock options exercised				$ 0
2000 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan				24 months
Exercise price as percentage of fair market value minimum				85%
Stock option increase	35,000	35,000	25,000
Extended term of stock plan to the date		10 years	10 years
Options shares reserved for issuance				325,000
Common stock, shares issued				299,545
Intrinsic value of options exercised				$ 2,300	$ 3,100,000	$ 3,600,000
Shares available for future grant				25,455

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shares of Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding	2,843,416	2,535,943
Stock options available for grant	2,171,128
Shares of common stock reserved for future issuance	5,039,999
2000 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options available for grant	25,455
Shares of common stock reserved for future issuance	25,455

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Activity under all Stock-Based Compensation Plans (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Equity [Abstract]
Outstanding, Number of Options, beginning balance	2,535,943
Options granted, Number of Options	517,851
Options exercised, Number of Options	(1,450)
Options forfeited, Number of Options	(95,339)
Options expired, Number of Options	(113,589)
Outstanding, Number of Options, ending balance	2,843,416	2,535,943
Exercisable, Number of Options	2,216,215
Vested and expected to vest, Number of Options	2,843,416
Outstanding, Number of Options, Weighted Average Exercise Price Per Share, beginning balance	$ 13.89
Options granted, Weighted Average Exercise Price Per Share	7.76
Options exercised, Weighted Average Exercise Price Per Share	5.77
Options forfeited, Weighted Average Exercise Price Per Share	12.48
Options expired, Weighted Average Exercise Price Per Share	10.26
Outstanding, Number of Options, Weighted Average Exercise Price Per Share, ending balance	12.97	$ 13.89
Exercisable, Number of Options, Weighted Average Exercise Price Per Share	13.28
Vested and expected to vest, Number of Options, Weighted Average Exercise Price Per Share	$ 12.97
Outstanding, Number of Options, Weighted Average Remaining Contractual Term	4 years 9 months 25 days	4 years 8 months 26 days
Exercisable, Number of Options, Weighted Average Remaining Contractual Term	3 years 9 months 14 days
Vested and expected to vest, Number of Options, Weighted Average Remaining Contractual Term	4 years 9 months 25 days
Outstanding, Number of Options, Aggregate Intrinsic Value		$ 1.7

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Employee Stock-Based Compensation Cost that has been Included in Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	$ 2,457	$ 2,688	$ 2,079
Cost of product revenues [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	20	19	13
Research and development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	1,215	1,245	981
Selling, general and administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	$ 1,222	$ 1,424	$ 1,085

Stockholders' Equity - Determin

Stockholders' Equity - Determining Fair Value - Additional Information (Detail) - 2000 Employee Stock Purchase Plan [Member] - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield in Black-Scholes option valuation model	$ 0
Shares purchased under Company's employee stock purchase plan	13,575	11,367	10,179
Recognition of expenses on shares purchased under employee stock purchase plan	$ 19,000	$ 57,000	$ 86,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 3,700,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 1 month 6 days
Proceeds from Stock Options Exercised	$ 8,000	$ 3,400,000	$ 3,200,000

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of Assumptions Used to Estimate Fair Value of Options Granted and Shares Purchased (Detail)		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 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%
Risk-free rate, maximum		1.49%
Expected term (in years)		6 months	6 months	6 months
Volatility, minimum		56%	56%	78%
Volatility, maximum		80%	71%	124%
Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate, minimum		1.80%	0.80%	0.50%
Risk-free rate, maximum		4.20%	1.50%	1.40%
Volatility, minimum		83%	85%	84%
Volatility, maximum		86%	86%	87%
Forfeiture rate	[1]	0%	0%	0%
Stock Option Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (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 term (in years)		7 years 3 months 18 days	7 years 9 months 18 days	7 years 3 months 18 days
[1] The Company accounts for forfeitures as they occur.

Stockholders' Equity - Summar_5

Stockholders' Equity - Summary of Stock Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Range of Exercise Price, $4.00-$5.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	$ 5.77
Options Outstanding, Range of Exercise Price, maximum	$ 4
Number of Options Outstanding | shares	388,747
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 7 months 20 days
Options Outstanding, Weighted-Average Exercise Price	$ 5.52
Number of Options Exercisable | shares	275,052
Options Exercisable, Weighted-Average Exercise Price	$ 5.76
Range of Exercise Price, $5.82-$6.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	6.77
Options Outstanding, Range of Exercise Price, maximum	$ 5.82
Number of Options Outstanding | shares	71,147
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	7 years 8 months 26 days
Options Outstanding, Weighted-Average Exercise Price	$ 6.34
Number of Options Exercisable | shares	40,936
Options Exercisable, Weighted-Average Exercise Price	$ 6.09
Range of Exercise Price, $8.71-$7.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	7.77
Options Outstanding, Range of Exercise Price, maximum	$ 8.71
Number of Options Outstanding | shares	315,022
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	8 years 11 months 26 days
Options Outstanding, Weighted-Average Exercise Price	$ 8.71
Number of Options Exercisable | shares	59,600
Options Exercisable, Weighted-Average Exercise Price	$ 8.71
Range of Exercise Price, $8.80-$8.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	8.77
Options Outstanding, Range of Exercise Price, maximum	$ 8.80
Number of Options Outstanding | shares	422,420
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	2 years 3 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 10.18
Number of Options Exercisable | shares	417,574
Options Exercisable, Weighted-Average Exercise Price	$ 10.19
Range of Exercise Price, $11.70-$9.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	9.77
Options Outstanding, Range of Exercise Price, maximum	$ 11.70
Number of Options Outstanding | shares	486,885
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	2 years 9 months 14 days
Options Outstanding, Weighted-Average Exercise Price	$ 12.26
Number of Options Exercisable | shares	483,510
Options Exercisable, Weighted-Average Exercise Price	$ 12.26
Range of Exercise Price, $12.60-$10.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	10.77
Options Outstanding, Range of Exercise Price, maximum	$ 12.60
Number of Options Outstanding | shares	297,424
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	3 years 2 months 4 days
Options Outstanding, Weighted-Average Exercise Price	$ 13.16
Number of Options Exercisable | shares	282,424
Options Exercisable, Weighted-Average Exercise Price	$ 13.16
Range of Exercise Price, $14.00-$11.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	11.77
Options Outstanding, Range of Exercise Price, maximum	$ 14
Number of Options Outstanding | shares	388,454
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 7 months 20 days
Options Outstanding, Weighted-Average Exercise Price	$ 18.17
Number of Options Exercisable | shares	241,237
Options Exercisable, Weighted-Average Exercise Price	$ 17.07
Range of Exercise Price, $20.90-$12.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	12.77
Options Outstanding, Range of Exercise Price, maximum	$ 20.90
Number of Options Outstanding | shares	380,089
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	3 years 6 months 21 days
Options Outstanding, Weighted-Average Exercise Price	$ 20.98
Number of Options Exercisable | shares	331,545
Options Exercisable, Weighted-Average Exercise Price	$ 20.97
Range of Exercise Price, $21.90-$13.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	13.77
Options Outstanding, Range of Exercise Price, maximum	$ 21.90
Number of Options Outstanding | shares	75,728
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 6 months 25 days
Options Outstanding, Weighted-Average Exercise Price	$ 24.32
Number of Options Exercisable | shares	66,837
Options Exercisable, Weighted-Average Exercise Price	$ 24.27
Range of Exercise Price, $28.00-$14.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	14.77
Options Outstanding, Range of Exercise Price, maximum	$ 28
Number of Options Outstanding | shares	17,500
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	2 years 5 months 12 days
Options Outstanding, Weighted-Average Exercise Price	$ 28
Number of Options Exercisable | shares	17,500
Options Exercisable, Weighted-Average Exercise Price	$ 28
Range of Exercise Price, $4.00 - $28.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	28
Options Outstanding, Range of Exercise Price, maximum	$ 4
Number of Options Outstanding | shares	2,843,416
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	4 years 9 months 25 days
Options Outstanding, Weighted-Average Exercise Price	$ 12.97
Number of Options Exercisable | shares	2,216,215
Options Exercisable, Weighted-Average Exercise Price	$ 13.28

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Deferred tax liability	$ 244,000	$ 244,000
Deferred tax assets	$ 244,000	$ 244,000
Statutory federal income tax rate	0.0021%	0.0021%	0.0021%
Increase (decrease) in valuation allowance of net deferred tax assets	$ 1,300,000	$ 2,000,000	$ (2,900,000)
Unrecognized tax benefits	13,068,000	12,421,000	10,888,000
Interest and penalty expense related to unrecognized tax benefits	$ 0	0	0
Valuation allowance, percentage	100%
Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards for income tax purposes	$ 317,700,000
Net operating loss carryforwards expiration amount	245,200,000
Net operating loss carryforwards non-expiration amount	$ 72,500,000
Tax carryforwards expire date	2023 through 2037
Research [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Tax carryforwards expire date	2023 through 2042
Research and development tax credits	$ 18,000,000
Interest and other income, net [Member]
Income Tax Contingency [Line Items]
Total income tax provision (benefit) expense	0	0	0
State [Member]
Income Tax Contingency [Line Items]
Total income tax provision (benefit) expense	0	$ 0	$ 0
Net operating loss carryforwards for income tax purposes	$ 243,800,000
Tax carryforwards expire date	2023 through 2042
State [Member] | Research [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 17,800,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expenses (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. federal taxes benefit at statutory rate	$ (7,420)	$ (7,616)	$ (122)
Change in valuation allowance	1,152	2,266	(2,022)
Stock-based compensation	371	641	268
Research and development tax credits	(1,449)	(954)	(1,132)
Expiring net operating losses	7,313	5,612	2,991
Other	$ 33	$ 51	$ 17

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Company's Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 83,262,000	$ 90,114,000
Research and other credits	20,602,000	19,197,000
Section 174 R&D capitalization	6,911,000
Deferred revenue		202,000
Stock-based compensation	2,603,000	2,741,000
Other	4,765,000	4,962,000
Total deferred tax assets	118,143,000	117,216,000
Valuation allowance for deferred tax assets	(117,639,000)	(116,358,000)
Deferred tax liabilities - right of use asset	(748,000)	(1,102,000)
Net deferred tax assets and liabilities	$ (244,000)	$ (244,000)

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 12,421	$ 10,888
Increase related to prior year tax positions	(188)	911
Increase related to current year tax positions	835	622
Balance at end of the year	$ 13,068	$ 12,421

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain from discontinued operations		$ 12,845
Evonik [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Asset purchase agreement subject to certain adjustments paid	$ 15,100
Gain from discontinued operations		$ 12,800

Discontinued Operations - Summa

Discontinued Operations - Summary of Discontinued Operations Reported in Statement of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total revenues			$ 4,918
Operating expenses:
Cost of product revenues			3,019
Research and development			476
Selling, general and administrative			515
Total costs and expenses			4,010
Income from discontinued operations			908
Other income:
Gain from discontinued operations			12,845
Net income from discontinued operations			$ 13,753
Net income (loss) per share
Net income per share, basic			$ 0.69
Net income per share, diluted			$ 0.69
Weighted-average shares used in computing net income per share basic and diluted
Weighted-average shares used in computing net income per share, Basic	22,777	22,505	19,946
Weighted-average shares used in computing net income per share, diluted	22,777	22,505	19,946

Discontinued Operations - Sum_2

Discontinued Operations - Summary of Non-cash Items Related to Discontinued Operations Included in Statement of Cash Flows (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Depreciation	$ 198
Stock-based compensation expense	91
Goodwill	229
Loss on disposal of property and equipment	129
Non-cash items, gross	647
Gain from discontinued operations	12,845
Non-cash items, net	$ (12,198)

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Feb. 03, 2023	Jun. 20, 2019	Dec. 31, 2022
Subsequent Event [Line Items]
Number of shares related to purchase and sales agreement		2,900,000
Sale of stock price per share		$ 5.20
Net proceeds from purchase agreement		$ 15.1
Subsequent Event, Description			On February 3, 2023, the Company entered into a securities purchase agreement (the “Purchase Agreement”) with two institutional investors
Subsequent Event [Member]
Subsequent Event [Line Items]
Gross proceeds from purchase agreement	$ 10
Net proceeds from purchase agreement	$ 8.8
Subsequent Event, Date	Feb. 03, 2023
Subsequent Event [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Number of shares related to purchase and sales agreement	1,700,000
Sale of stock price per share	$ 0.0001
Subsequent Event [Member] | Pre-funded Warrants [Member]
Subsequent Event [Line Items]
Sale of stock price per share	$ 4.99999
Number of warrants to purchase common stock	300,000
Warrants exercise price	$ 0.00001
Subsequent Event [Member] | Warrants [Member]
Subsequent Event [Line Items]
Sale of stock price per share	$ 5
Number of warrants to purchase common stock	2,000,000
Warrants exercise price	$ 5
Warrants exercisable term	5 years
Subsequent Event [Member] | Pre-funded Warrant and Common Warrant [Member]
Subsequent Event [Line Items]
Percentage of ownership on outstanding common stock immediately after exercise	4.99%
Percentage of ownership on outstanding common stock at election of holder	9.99%