DURECT (DRRX) 10-K 8 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Mar. 04, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	DRRX
Entity Registrant Name	DURECT CORP
Entity Central Index Key	1,082,038
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	Accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		162,059,718
Entity Public Float			$ 207,649,177

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 31,644	$ 29,375
Short-term investments	2,671	7,384
Accounts receivable (net of allowances of $102 at December 31, 2018 and $155 at December 31, 2017)	1,757	2,376
Inventories, net	3,421	3,163
Prepaid expenses and other current assets	2,247	3,060
Total current assets	41,740	45,358
Property and equipment, net	605	929
Goodwill	6,399	6,399
Long-term restricted investments	150	150
Other long-term assets	1,105	277
Total assets	49,999	53,113
Current liabilities:
Accounts payable	1,589	1,520
Accrued liabilities	4,668	5,511
Contract research liabilities	1,405	834
Deferred revenue, current portion		682
Term loan, current portion, net		7,281
Total current liabilities	7,662	15,828
Deferred revenue, non-current portion	812	1,093
Term loan, non-current portion, net	20,533	13,578
Other long-term liabilities	992	1,126
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: 350,000 shares authorized; 162,060 and 150,837 shares issued and outstanding at December 31, 2018 and 2017, respectively	16	15
Additional paid-in capital	488,608	465,246
Accumulated other comprehensive loss		(1)
Accumulated deficit	(468,624)	(443,772)
Stockholders’ equity	20,000	21,488
Total liabilities and stockholders’ equity	$ 49,999	$ 53,113

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Allowances for accounts receivable	$ 102	$ 155
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	350,000,000	350,000,000
Common stock, shares issued	162,060,000	150,837,000
Common stock, shares outstanding	162,060,000	150,837,000

Statements of Operations And Co

Statements of Operations And Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total revenues	$ 18,564	$ 49,170	$ 14,025
Operating expenses:
Cost of product revenues	$ 4,263	$ 6,633	$ 5,290
Type of cost, good or service [extensible list]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
Research and development	$ 25,501	$ 31,609	$ 29,274
Selling, general and administrative	12,419	13,165	11,825
Total operating expenses	42,183	51,407	46,389
Loss from operations	(23,619)	(2,237)	(32,364)
Other income (expense):
Interest and other income	870	967	143
Interest expense	(2,573)	(2,425)	(2,288)
Net other expense	(1,703)	(1,458)	(2,145)
Net loss	(25,322)	(3,695)	(34,509)
Net change in unrealized gain on available-for-sale securities, net of tax	1	2	11
Total comprehensive loss	$ (25,321)	$ (3,693)	$ (34,498)
Net loss per share
Basic	$ (0.16)	$ (0.03)	$ (0.26)
Diluted	$ (0.16)	$ (0.03)	$ (0.26)
Weighted-average shares used in computing net loss per share
Basic	159,834	145,273	133,163
Diluted	159,834	145,273	133,163
Collaborative Research and Development and Other Revenue [Member]
Total revenues	$ 8,207	$ 23,577	$ 1,880
Product Revenue, Net [Member]
Total revenues	$ 10,357	13,093	$ 12,145
Revenue From Sale of Intellectual Property Rights [Member]
Total revenues		$ 12,500

Statement of Stockholders' Equi

Statement of Stockholders' Equity - USD ($) shares in Thousands, $ 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, 2015	$ 14,883	$ 12	$ 420,453	$ (14)	$ (405,568)
Beginning balance, shares at Dec. 31, 2015		121,839
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	410		410
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		413
Issuance of common stock upon equity financings, net of issuance costs	23,745	$ 2	23,743
Issuance of common stock upon equity financings, net of issuance cost, shares		19,045
Issuance of fully vested options to settle accrued liabilities	1,143		1,143
Stock-based compensation expense from stock options and ESPP shares	2,655		2,655
Net loss	(34,509)				(34,509)
Change in unrealized gain on available-for-sale securities, net of tax	11			11
Ending balance at Dec. 31, 2016	8,338	$ 14	448,404	(3)	(440,077)
Ending balance, shares at Dec. 31, 2016		141,297
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	649		649
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		667
Issuance of common stock upon equity financings, net of issuance costs	11,989	$ 1	11,988
Issuance of common stock upon equity financings, net of issuance cost, shares		8,873
Issuance of fully vested options to settle accrued liabilities	1,600		1,600
Stock-based compensation expense from stock options and ESPP shares	2,605		2,605
Net loss	(3,695)				(3,695)
Change in unrealized gain on available-for-sale securities, net of tax	2			2
Ending balance at Dec. 31, 2017	21,488	$ 15	465,246	(1)	(443,772)
Ending balance, shares at Dec. 31, 2017		150,837
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	1,725		1,725
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		1,594
Issuance of common stock upon equity financings, net of issuance costs	16,780	$ 1	16,779
Issuance of common stock upon equity financings, net of issuance cost, shares		9,629
Issuance of fully vested options to settle accrued liabilities	1,860		1,860
Stock-based compensation expense from stock options and ESPP shares	2,998		2,998
Net loss	(25,322)				(25,322)
Change in unrealized gain on available-for-sale securities, net of tax	1			$ 1
Adjustment due to changes in accounting policies	470				470
Ending balance at Dec. 31, 2018	$ 20,000	$ 16	$ 488,608		$ (468,624)
Ending balance, shares at Dec. 31, 2018		162,060

Statement of Stockholders' Eq_2

Statement of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Stockholders Equity [Abstract]
Stock issuance costs	$ 566	$ 374	$ 1,364

Statement of Cash Flows

Statement of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net loss		$ (25,322)	$ (3,695)	$ (34,509)
Adjustments to reconcile net loss to net cash used in operating activities:
Sale of intellectual property rights for non-operating purposes			(500)
Depreciation and amortization		254	437	416
Stock-based compensation		2,998	2,605	2,655
Inventory write-down		291	2,259	687
Amortization of debt issuance cost		149	62	104
Loss on debt extinguishment				9
Net accretion/amortization on investments		84	(41)	(216)
Changes in assets and liabilities:
Accounts receivable		619	(1,222)	1,068
Inventories		(549)	(140)	(552)
Prepaid expenses and other assets		(15)	(1,115)	656
Accounts payable		69	(566)	800
Accrued liabilities		1,594	1,594	1,419
Contract research liability		571	51	208
Deferred revenue		(493)	(1,072)	(38)
Total adjustments		5,572	2,352	7,216
Net cash used in operating activities		(19,750)	(1,343)	(27,293)
Cash flows from investing activities
Sale of intellectual property rights for non-operating purposes			500
Purchases of property and equipment		(93)	(69)	(147)
Purchases of available-for-sale securities		(9,588)	(8,373)	(24,400)
Proceeds from maturities of available-for-sale securities		14,218	20,632	30,584
Net cash provided by investing activities		4,537	12,690	6,037
Cash flows from financing activities
Payments on equipment financing obligations		(9)	(14)	(19)
Net proceeds from issuances of common stock upon exercise of stock options, and purchases of ESPP shares		1,725	649	410
Net proceeds from issuances of common stock in connection with equity financings		16,780	11,989	23,745
Term loan amendment cost		(1,014)		(173)
Payment of final payment for term loan				(886)
Net cash provided by financing activities		17,482	12,624	23,077
Net increase in cash and cash equivalents		2,269	23,971	1,821
Cash, cash equivalents, and restricted cash, beginning of the period	[1]	29,525	5,554	3,733
Cash, cash equivalents, and restricted cash, end of the period	[1]	31,794	29,525	5,554
Supplemental disclosure of cash flow information
Cash paid for interest		1,886	1,703	1,611
Supplementary disclosure of non-cash financing information
Fully vested options issued to settle accrued liabilities		$ 1,860	$ 1,600	$ 1,143
[1]	Includes restricted cash of $150,000 (presented as long term restricted investments) on the balance sheets at both December 31, 2018 and 2017, respectively, and $250,000 at December 31, 2016.

Statement of Cash Flows (Parent

Statement of Cash Flows (Parenthetical) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Long Term Restricted Investments [Member]
Restricted cash	$ 150,000	$ 150,000	$ 250,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
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 has several products under development by itself and with third party collaborators. The Company also manufactures and sells osmotic pumps used in laboratory research, and designs, develops and manufactures a wide range of standard and custom biodegradable polymers and excipients for pharmaceutical and medical device clients for use as raw materials in their products. In addition, the Company conducts research and development of pharmaceutical products in collaboration with third party pharmaceutical and biotechnology companies. Basis of Presentation 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 deliverables and evaluation of milestones with respect to our collaborations, the amounts of revenues, recoverability of inventory, certain accrued liabilities including accrued clinical trial liability, 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 believe 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. Reclassifications Certain prior period amounts on the accompanying Balance Sheets have been reclassified to conform to current period presentation. The Company has reclassified the accretion of final payment of the term loan from other long-term liabilities to net non-current portion of the term loan on the balance sheets as of December 31, 2018 and 2017. Liquidity and Need to Raise Additional Capital As of December 31, 2018, the Company has an accumulated deficit of $468.6 million as well as negative cash flows from operating activities. The Company historically has had negative cash flows from operating activities and expects its negative cash flows to continue. The Company will continue to require substantial funds to continue research and development, including clinical trials of its product candidates. Management’s plans in order to meet its operating cash flow requirements include seeking additional collaborative agreements for certain of its programs and achieving milestone and other payments under its collaboration and licensing agreements as well as financing activities such as public offerings and private placements of its common stock, preferred stock offerings, issuances of debt and convertible debt instruments. There are no assurances that such additional funding will be obtained 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. 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. 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 A portion of the Company’s revenue is derived from its ALZET mini pump product line, LACTEL biodegradable polymer product line and the sale of certain excipients for Methydur and one excipient that is included in a currently marketed animal health product. In 2018, revenue from the sale of products from the ALZET product line and the LACTEL product line accounted for 38% and 18% of total revenue, respectively. In 2017, revenue from the ALZET product line and the LACTEL product line accounted for 14% and 12% of total revenue, respectively. In 2016, revenue from the ALZET product line and the LACTEL product line accounted for 51% and 31% of total revenue, respectively. In 2018, Indivior and a pharmaceutical company with which the Company has a feasibility agreement accounted for 27% and 14% of the Company’s total revenues, respectively. In 2017, Sandoz and Indivior accounted for 41% and 25% of the Company’s total revenues, respectively. In 2016, Tolmar accounted for 15% of the Company’s total revenues. Total revenue by geographic region for the years 2018, 2017 and 2016 are as follows (in thousands): Year ended December 31, 2018 2017 2016 Europe $ 8,118 $ 34,261 $ 1,945 United States 7,990 11,323 9,082 Japan 978 1,395 1,413 Others 1,478 2,191 1,585 Total $ 18,564 $ 49,170 $ 14,025 Revenue by geography is determined by the location of the customer. Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. Inventories, in part, include certain excipients that are sold to a customer for a currently marketed animal health product and included in several products in development, or awaiting regulatory approval or commercial launch. In October 2017, the Company announced that PERSIST, the Phase 3 clinical trial for POSIMIR, did not meet its primary efficacy endpoint. As a result, the Company wrote down certain lots of inventory which are no longer considered to be probable for use prior to expiration and prepaid inventory related to a minimum purchase agreement for an excipient. In addition, the Company recorded a liability related to a minimum purchase agreement for the same excipient. In 2017, the Company recorded charges to cost of goods sold of approximately $2.0 million, of which approximately $503,000 related to the write-down of the cost basis of inventory on hand, $500,000 related to the prepaid inventory for the minimum purchase commitment for this excipient, and $1.0 million related to the accrual of a liability for the remaining minimum purchase commitment for the same excipient. As of December 31, 2018, the remaining carrying value of the excipient in the Company’s inventory was $68,000. In the event that management determines that the Company will not utilize all of these materials, there could be a potential write-off related to this inventory. If the Company is able to subsequently sell products made with raw materials that were previously written down, the Company will report an unusually high gross profit as there will be no associated cost of goods for these materials. The Company’s inventories consisted of the following (in thousands): December 31, 2018 2017 Raw materials $ 223 $ 282 Work in-process 1,486 1,182 Finished goods 1,712 1,699 Total inventories $ 3,421 $ 3,163 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 at the reporting unit level. 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 expected 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. As of December 31, 2018, the carrying value of goodwill was approximately $6.4 million and no impairment of goodwill has been recorded for any of the periods presented. The Company evaluates goodwill for impairment at least annually. In 2018, 2017 and 2016, goodwill was evaluated and no indicators of impairment were identified. 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, 2018, there have been no material impairment losses. 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. See Note 8 for further information regarding stock-based compensation. Revenue Recognition The Company enters into license and collaboration agreements under which the Company may receive upfront license fees, research funding and contingent milestone payments and royalties. Prior to January 1, 2018, the Company evaluated the accounting treatment under these agreements including whether multiple deliverables existed, how the deliverables should be separated and how the consideration should be allocated to one or more units of accounting. For the Company’s collaborations with multiple deliverables, the Company had concluded that the deliverables were not separable and the arrangements should be accounted for as a combined unit of accounting. As a combined unit of accounting, the Company recognized the consideration for the combined unit of accounting in the same manner as the revenue was recognized for the final deliverable, which was generally ratably over the longest period of involvement. For example, upfront payments received upon execution of collaborative agreements were recorded as deferred revenue and recognized as collaborative research and development revenue based on a straight-line basis over the period of the Company’s continuing involvement with the third-party collaborator pursuant to the applicable agreement. Such period generally represented the longer of the estimated research and development period or other continuing obligation period defined in the respective agreements between the Company and its third-party collaborators. If the Company determined that the expected timeline for a project and therefore the Company’s continuing involvement was materially different than we previously assumed, the Company adjusted the period over which it recognized the deferred revenue. Effective January 1, 2018, the Company adopted FASB ASC Topic 606, Revenue from Contracts with Customers, or ASC 606. In accordance with ASC 606, the Company changed certain characteristics of its revenue recognition accounting policy as described below. ASC 606 was applied using the modified retrospective method, where the cumulative effect of the initial application was recognized as an adjustment to opening retained earnings at January 1, 2018. Therefore, comparative prior periods have not been adjusted and continue to be reported under FASB ASC Topic 605, Revenue Recognition, or ASC 605. The Company recorded a net increase to opening accumulated deficit of $470,000 with a corresponding entry to deferred revenue as of January 1, 2018 due to the cumulative impact of adopting Topic 606, with the impact relating to a reduction in the Company’s deferred collaborative research and development revenues. There was no impact to reported total assets, revenues and operating expenses for the twelve months ended December 31, 2018 as a result of applying Topic 606. Product Revenue, Net The Company sells osmotic pumps used in laboratory research, and designs, develops and manufactures a wide range of standard and custom biodegradable polymers and excipients for pharmaceutical and medical device clients for use as raw materials in their products. Revenues from product sales are recognized when the customer obtains control of the Company’s product, which occurs at a point in time, typically upon shipment to the customer. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less. Trade Discounts and Allowances: The Company provides certain customers with discounts that are explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized. Product Returns: Consistent with industry practice, the Company generally offers customers a limited right of return for products that have been purchased from the Company. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using its historical sales information. The Company expects product returns to be minimal. Collaborative Research and Development Revenues The Company enters into license agreements which are within the scope of Topic 606, under which it licenses certain rights to its product candidates to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees; reimbursement of development costs incurred by the Company under approved work plans; development, regulatory and commercial milestone payments; payments for manufacturing supply services the Company provides through its contract manufacturers; and royalties on net sales of licensed products. Each of these payments results in collaborative research and development revenues, except for revenues from royalties on net sales of licensed products, which are classified as royalty revenues. In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the standalone selling price, which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. The Company expects to recognize revenue for the variable consideration currently being constrained when it is probable that a significant revenue reversal will not occur. Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments: At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaborative research and development revenues and net income (loss) in the period of adjustment. Manufacturing Supply Services: Arrangements that include a promise for future supply of drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide a material right to the customer and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded in collaborative research and development revenue when the customer obtains control of the goods, which is upon delivery. Royalties and Earn-outs: For arrangements that include sales-based royalties or earn-outs, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any significant royalty revenue resulting from the Company’s collaborative arrangements or any earn-out revenue from the Company’s patent purchase agreement with Indivior. The cumulative effect of the changes made to the Company’s January 1, 2018 balance sheet for the adoption of ASC 606 Revenue – Revenue from Contract with Customers was as follows (in thousands): Balance at December 31, 2017 Adjustments Due to ASC 606 Balance at January 1, 2018 Balance Sheet Liabilities Deferred revenue, non-current portion $ 1,093 $ 470 $ 623 Equity Accumulated deficit $ (443,772 ) $ 470 $ (443,302 ) During the twelve months ended December 31, 2018, the Company did not recognize any revenue as a result of changes in the contract asset and the contract liability balances associated with the Company’s deferred research and development revenues for the Company’s collaboration agreements as a result of adoption of ASC 606. In accordance with the new revenue standard requirements, the disclosure of the impact of adoption on balance sheet, statement of operations and comprehensive loss, and statement of cash flows for the twelve months ended December 31, 2018 was as follows (in thousands): As of December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Balance Sheet Liabilities Deferred revenue, non-current portion $ 812 $ 1,282 $ (470 ) For the year ended December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Statement of Operations and Comprehensive Loss Collaborative research and development and other revenue $ 8,207 $ 8,207 $ - Product revenue, net 10,357 10,357 - Total revenues $ 18,564 $ 18,564 $ - For the year ended December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Statement of Cash Flows Cash flow from Operating Activities Deferred revenue, non-current portion $ (493 ) $ (23 ) $ (470 ) 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, reimbursements of research and development expenses incurred 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 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, 2018 2017 2016 Numerators: Net loss $ (25,322 ) $ (3,695 ) $ (34,509 ) Denominators: Weighted average shares used to compute basic net loss per share 159,834 145,273 133,163 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute diluted net loss per share 159,834 145,273 133,163 Net loss per share: Basic $ (0.16 ) $ (0.03 ) $ (0.26 ) Diluted $ (0.16 ) $ (0.03 ) $ (0.26 ) The computation of diluted net loss per share for the years ended 2018, 2017 and 2016 excludes the impact of options to purchase 16.6 million, 20.1 million and 18.7 million shares of common stock outstanding, respectively, at December 31, 2018, 2017 and 2016, 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. Operating Leases The Company leases administrative, manufacturing and laboratory facilities under operating leases. Lease agreements may include rent holidays, rent escalation clauses and tenant improvement allowances. The Company recognizes scheduled rent increases on a straight-line basis over the lease term beginning with the date the Company takes possession of the leased space. The Company records tenant improvement allowances as deferred rent liabilities and amortizes the deferred rent over the terms of the lease to rent expense on the statements of operations and comprehensive loss. Recent Accounting Pronouncements In August 2018, the FASB issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates certain disclosure requirements for fair value measurements for all entities, requires public entities to disclose certain new information and modifies some disclosure requirements. This standard is effective for fiscal years beginning after December 15, 2019, including interim reporting periods within those years, with early adoption permitted. The Company does not expect the adoption of this standard to have a material effect on its financial statements. In June 2018, the FASB issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation – Stock Compensation (Topic 718), which expands the scope of ASC 718 to include all share-based payment arrangements related to the acquisition of goods and services from both nonemployees and employees. Under the new standard, most of the guidance on stock compensation payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. This standard is effective for fiscal years beginning after December 15, 2018, including interim reporting periods within those years, with early adoption permitted. The Company does not expect the adoption of this standard to have a material effect on its financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Commitments,

Strategic Agreements

Strategic Agreements	12 Months Ended
	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Strategic Agreements	2. Strategic Agreements The collaborative research and development and other revenues associated with the Company’s major third-party collaborators are as follows (in thousands): Year ended December 31, 2018 2017 2016 Collaborator/Counterparty Indivior UK Limited (Indivior) (1) $ 5,019 $ — $ — Santen Pharmaceutical Co. Ltd. (Santen) (2) 102 294 514 Sandoz AG (Sandoz) (3) — 20,000 — Zogenix, Inc. (Zogenix) (4) — 835 555 Pain Therapeutics, Inc. (Pain Therapeutics) — 109 670 Other (5) 3,086 2,339 141 Total collaborative research and development and other revenue $ 8,207 $ 23,577 $ 1,880 (1) Amount consists of a $5.0 million milestone payment earned from Indivior upon NDA approval of PERSERIS in 2018 and earn-out revenue from PERSERIS net sales compared with zero in 2017 and 2016; we and Indivior signed a license agreement effective July 2017. ( 2 ) Amounts related to recognition of upfront fees were zero in 2018, $199,000 in 2017, and $228,000 in 2016. The Company and Santen signed a license agreement effective December 2014. In January 2018, the Company was notified by Santen that due to a shift in near term priorities, Santen has elected to reallocate research and development resources and put the Company’s program on pause until further notice. While the main program is on pause, the parties are working together on a limited set of research and development activities funded by Santen. ( 3 ) Amounts related to recognition of upfront fees were zero in 2018, $20.0 million in 2017 and zero in 2016; the Company and Sandoz signed a license agreement effective June 2017. As of December 31, 2017, all of the $20.0 million upfront fee had been recognized as revenue as the Company’s contractual performance obligations had been fulfilled. In January 2019, the license agreement was terminated. ( 4 ) Amounts related to ratable recognition of upfront fees were zero in 2018, $833,000 in 2017, and $208,000 in 2016. The Company and Zogenix signed a license agreement effective July 2011. In August 2017, the Company and Zogenix terminated their Development and License Agreement dated July 11, 2011 relating to the development and commercialization of Relday. ( 5 ) Includes revenue recognized associated with the Company’s feasibility agreements for years ended December 31, 2018, 2017 and 2016. As of March 4, 2019, the Company had potential milestones of up to $77.5 million that the Company may receive in the future under its collaborative arrangements, of which $14.5 million are development-based milestones and $63.0 million are sales-based milestones. Within the category of development-based milestones, $2.0 million are related to early stage clinical testing (defined as Phase 1 or 2 activities), $3.0 million are related to late stage clinical testing (defined as Phase 3 activities), $3.0 million are related to regulatory filings, and $6.5 million are related to regulatory approvals. No payments were received between December 31, 2018 and March 4, 2019. Patent Purchase Agreement with Indivior On September 26, 2017, the Company entered into a Patent Purchase Agreement (the “Agreement”) with Indivior. Pursuant to the Agreement, the Company assigned to Indivior certain patents that may provide further intellectual property protection for PERSERIS ™ Agreement with Pain Therapeutics, Inc. In December 2002, the Company entered into an exclusive agreement with Pain Therapeutics, Inc. (Pain Therapeutics) to develop and commercialize on a worldwide basis REMOXY ER and other oral sustained release, abuse deterrent opioid products incorporating four specified opioid drugs, using the ORADUR technology. This agreement currently covers only REMOXY ER. Under the terms of this agreement, Pain Therapeutics paid the Company an upfront license fee of $1.0 million, with the potential for an additional $3.0 million in performance milestone payments based on the successful development and approval of REMOXY ER. Of these potential milestones, all $3.0 million are development-based milestones. There are no sales-based milestones under the agreement. As of December 31, 2018, the Company had received $1.5 million in cumulative milestone payments. Total collaborative research and development revenue recognized for REMOXY-related work performed by the Company for Pain Therapeutics was zero in 2018, $109,000 in 2017, and $670,000 in 2016. The cumulative aggregate payments received by the Company from Pain Therapeutics as of December 31, 2018 were $40.4 million under this agreement. In 2018, 2017 and 2016, the Company recognized zero, zero and $653,000 of product revenue related to key excipients for REMOXY ER and the associated cost of goods sold was zero, zero and $216,000, respectively. Agreement with Santen Pharmaceutical Co., Ltd. On December 11, 2014, the Company and Santen Pharmaceutical Co., Ltd. (Santen) entered into a definitive agreement (the Santen Agreement). Pursuant to the Santen Agreement, the Company granted Santen an exclusive worldwide license to the Company’s proprietary SABER formulation platform and other intellectual property to develop and commercialize a sustained release product utilizing the Company’s SABER technology to deliver an ophthalmology drug. Santen controls and funds the development and commercialization program, and the parties established a joint management committee to oversee, review and coordinate the development activities of the parties under the Santen Agreement. In connection with the Santen agreement, Santen agreed to pay the Company an upfront fee of $2.0 million in cash and to make contingent cash payments to the Company of up to $76.0 million upon the achievement of certain milestones, of which $13.0 million are development-based milestones and $63.0 million are commercialization-based milestones including milestones requiring the achievement of certain product sales targets (none of which has been achieved as of December 31, 2018). Santen will also pay for certain Company costs incurred in the development of the licensed product. If the product is commercialized, the Company would also receive a tiered royalty on annual net product sales ranging from single-digit to the low double digits, determined on a country-by-country basis. As of December 31, 2018, the cumulative aggregate payments received by the Company under this agreement were $3.3 million. In January 2018, the Company was notified by Santen that due to a shift in near term priorities, Santen elected to reallocate research and development resources and put the Company’s program on pause until further notice. The following table provides a summary of collaborative research and development revenue recognized under the Santen Agreement (in thousands). Year Ended December 31, 2018 2017 2016 Ratable recognition of upfront payment $ — $ 199 $ 228 Research and development expenses reimbursable by Santen 102 95 286 Total collaborative research and development revenue $ 102 $ 294 $ 514 Agreement with Sandoz AG. In May 2017, the Company and Sandoz AG (“Sandoz”) entered into a license agreement to develop and market POSIMIR (bupivacaine extended release solution) in the United States. Following expiration of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (HSR), the agreement became effective in June 2017. The Company retained commercialization rights in the rest of the world. Under terms of the agreement, Sandoz made an upfront payment of $20 million, and the Company remained eligible for up to an additional $30 million in milestone payments based on successful development and regulatory milestones, up to an additional $230 million in sales-based milestones, and a tiered double-digit royalty on product sales for a defined period. DURECT was responsible for the completion of the ongoing PERSIST Phase 3 clinical trial for POSIMIR as well as FDA interactions through potential approval. If approved, DURECT also has certain manufacturing obligations under this agreement. Sandoz will have exclusive commercialization rights in the United States upon regulatory approval with sole funding responsibility for commercialization activities. Sandoz will pay the Company a tiered double-digit royalty on product sales for a defined period, after which the license granted to Sandoz shall convert to a non-exclusive, fully paid, royalty-free, irrevocable and perpetual license. The term of the agreement shall be for the duration of Sandoz’s obligation to pay royalties for product sales under the Agreement. The agreement provides each party with specified termination rights, including the right of Sandoz to terminate at will after a specified period and each party to terminate the agreement upon material breach of the agreement by the other party. The failure of the PERSIST trial for POSIMIR to achieve its primary endpoint gives Sandoz a right to terminate the Company’s agreement with them on thirty days’ notice, in addition to the rights they have to terminate for convenience on six months’ notice. In May 2018, the Company and Sandoz entered into an amendment (the “Amendment”) to the license agreement. Pursuant to the Amendment, the Company is eligible for up to $30 million in milestone payments based on NDA approval, and remains eligible for up to an additional $230 million in sales-based milestones and a tiered double-digit royalty on product sales for a defined period. Pursuant to the Amendment, each party is also permitted to develop or commercialize competing products. The Amendment also includes modifications to the Company’s development obligations and to both parties’ termination provisions, including a right for the Company to terminate for convenience prior to NDA approval, and a new termination fee payable to the Company in the event that Sandoz terminates the agreement for convenience. The Company evaluated the agreement under the accounting guidance for multiple element arrangements and identified three deliverables: the license to develop and market POSIMIR, the research and development services and the manufacturing services. Given that the delivery of the manufacturing services by the Company is dependent upon approval of POSIMIR by the FDA, and that the fee to be received by the Company for these services, should they be delivered, is consistent with their estimated selling price, the Company considers the manufacturing services to be a contingent deliverable and has excluded them from the initial measurement and allocation of the arrangement consideration. The Company evaluated the license deliverable and concluded that it did not have stand alone value separate from the research and development services and accordingly combined these deliverables into a single unit of accounting. The Company allocated the arrangement consideration, which consists of the $20.0 million upfront payment, to this single unit of accounting. As of December 31, 2017, all of the $20.0 million upfront fee had been recognized as revenue as the Company’s contractual performance obligations had been fulfilled. Total collaborative research and development revenue recognized by the Company for Sandoz was zero for 2018 and 2016, respectively, compared with $20.0 million for 2017. The cumulative aggregate payments received by the Company from Sandoz as of December 31, 2018 were $20.0 million under this agreement. On January 2, 2019, the Company received written notice from Sandoz AG that effective January 27, 2019, Sandoz AG is terminating the Development and Commercialization Agreement, dated May 5, 2017, as amended (the “Sandoz Agreement”). As a result of this termination, Sandoz AG will be returning its exclusive commercialization rights to develop and market POSIMIR® (bupivacaine extended release solution) in the United States. POSIMIR is the Company’s investigational post-operative pain relief depot that utilizes the Company’s patented SABER® technology and is designed to deliver bupivacaine to provide up to three days of pain relief after surgery. The parties are in dispute with regard to Sandoz AG’s obligation to pay a termination fee to the Company. The Company has initiated a formal dispute resolution process related to the termination fee. Agreement with Zogenix, Inc. On July 11, 2011, the Company and Zogenix, Inc. (Zogenix) entered into a Development and License Agreement (the Zogenix Agreement). The Company and Zogenix had previously been working together under a feasibility agreement pursuant to which the Company’s research and development costs were reimbursed by Zogenix. Under the Zogenix Agreement, Zogenix was responsible for the clinical development and commercialization of a proprietary, long-acting injectable formulation of risperidone using the Company’s SABER controlled-release formulation technology potentially in combination with Zogenix’s DosePro® needle-free, subcutaneous drug delivery system. DURECT was responsible for non-clinical, formulation and CMC development activities. The Company was to be reimbursed by Zogenix for its research and development efforts on the product. Zogenix paid a non-refundable upfront fee to the Company of $2.25 million in July 2011. The Company’s research and development services were considered integral to utilizing the licensed intellectual property and, accordingly, the deliverable were accounted for as a single unit of accounting. The $2.25 million upfront fee had been recognized as collaborative research and development revenue ratably over the term of the Company’s research and development involvement with Zogenix with respect to this product candidate. The Company granted to Zogenix an exclusive worldwide license, with sub-license rights, to the Company’s intellectual property rights related to the Company’s proprietary polymeric and non-polymeric controlled-release formulation technology to make and have made, use, offer for sale, sell and import risperidone products, where risperidone is the sole active agent, for administration by injection in the treatment of schizophrenia, bipolar disorder or other psychiatric related disorders in humans. The Company retained the right to supply Zogenix’s Phase 3 clinical trial and commercial product requirements on the terms set forth in the Zogenix Agreement. Zogenix was permitted to terminate the Zogenix Agreement without cause at any time upon prior written notice, and either party was permitted to terminate the Zogenix Agreement upon certain circumstances including written notice of a material uncured breach. In August 2017, the Company and Zogenix terminated the Zogenix Agreement. Under the mutual termination agreement, Zogenix’s development and commercialization rights were returned to the Company, and Zogenix transferred to the Company all regulatory filings and development information related to Relday. As a result of the termination of the Zogenix agreement, the Company recognized revenue during the third quarter of 2017 for the remaining $750,000 of deferred revenue related to the upfront fee as the Company had no remaining performance obligations under the agreement; this recognition of revenue did not result in additional cash proceeds to the Company. The following table provides a summary of collaborative research and development revenue recognized under the agreements with Zogenix (in thousands). The cumulative aggregate payments received by the Company as of December 31, 2018 were $20.1 million under these agreements. Year Ended December 31, 2018 2017 2016 Ratable recognition of upfront payment $ — $ 833 $ 208 Research and development expenses reimbursable by Zogenix — 2 347 Total collaborative research and development revenue $ — $ 835 $ 555

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2018
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, 2018 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 502 $ — $ — $ 502 Certificates of deposit — 150 — 150 Commercial paper — 32,224 — 32,224 Total $ 502 $ 32,374 $ — $ 32,876 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, 2017 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 568 $ — $ — $ 568 Certificates of deposit — 150 — 150 Commercial paper — 33,307 — 33,307 Corporate debt — 1,297 — 1,297 Total $ 568 $ 34,754 $ — $ 35,322 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, corporate debt securities, and U.S. Government agency securities are classified as Level 2 financial assets. The fair value of the Level 2 assets is estimated using pricing models using current observable market information for similar securities. The Company’s Level 2 investments include U.S. government-backed securities and corporate securities that are valued based upon observable inputs that may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data including market research publications. The fair value of commercial paper is based upon the time to maturity and discounted using the three-month treasury bill rate. The average remaining maturity of the Company’s Level 2 investments as of December 31, 2018 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, 2018 and 2017 (in thousands): December 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 502 $ — $ — $ 502 Certificates of deposit 150 — — 150 Commercial paper 32,224 — — 32,224 $ 32,876 $ — $ — $ 32,876 Reported as: Cash and cash equivalents $ 30,055 $ — $ — $ 30,055 Short-term investments 2,671 — — 2,671 Long-term restricted investments 150 — — 150 $ 32,876 $ — $ — $ 32,876 December 31, 2017 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 568 $ — $ — $ 568 Certificates of deposit 150 — — 150 Commercial paper 33,307 — — 33,307 Corporate debt 1,298 — (1 ) 1,297 $ 35,323 $ — $ (1 ) $ 35,322 Reported as: Cash and cash equivalents $ 27,788 $ — $ — $ 27,788 Short-term investments 7,385 — (1 ) 7,384 Long-term restricted investments 150 — — 150 $ 35,323 $ — $ (1 ) $ 35,322 The following is a summary of the cost and estimated fair value of available-for-sale securities at December 31, 2018, by contractual maturity (in thousands): December 31, 2018 Amortized Cost Estimated Fair Value Mature in one year or less $ 32,374 $ 32,374 $ 32,374 $ 32,374 There were no securities that have had an unrealized loss for more than 12 months as of December 31, 2018. As of December 31, 2018, 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, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment consist of the following (in thousands): December 31, 2018 2017 Equipment $ 12,785 $ 12,688 Leasehold improvement 9,828 9,929 Construction-in-progress 33 119 22,646 22,736 Less accumulated depreciation and amortization (22,041 ) (21,807 ) Property and equipment, net $ 605 $ 929 Depreciation expense was $254,000, $437,000 and $416,000 in 2018, 2017 and 2016, respectively. Amortization expense was zero in 2018, 2017 and 2016 for assets held under capital leases. As of December 31, 2018, the Company has recorded $470,000 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, 2018
Text Block [Abstract]
Restricted Investments	5. Restricted Investments As of December 31, 2018 and 2017, 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, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments	6. Commitments Operating Leases In April 2018, the Company entered into a lease amendment on a 24,634 square foot facility in Vacaville, California. In August 2018 and September 2018, the Company entered into lease amendments on a 30,149 square foot facility and a 20,100 square foot facility in Cupertino, California. 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) Birmingham, AL 21,540 sq. ft. Office, Laboratory and Manufacturing Lease expires 2021 (with two options to renew the lease term for an additional five years each after the current lease expires) 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 the years ended December 31, 2018, 2017 and 2016, respectively. Future minimum payments under these noncancelable leases are as follows (in thousands): Year ending December 31, Operating Leases 2019 $ 2,122 2020 2,200 2021 2,126 2022 1,991 2023 and thereafter 2,245 $ 10,684 Other Purchase Commitments In 2005, the Company entered into a supply agreement with a vendor. The remaining minimum purchase commitment under this agreement was $500,000 in 2018, which had been recorded as an accrued liability on the Company’s Balance Sheet at December 31, 2018, and which was charged to cost of goods sold in the Company’s Statements of Operations and Comprehensive Loss in 2017.

Term Loan

Term Loan	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Term Loan	7. Term Loan In July 2016, the Company entered a $20.0 million secured single-draw term loan with Oxford Finance LLC (Oxford Finance). The Loan Agreement provides for interest only payments for the first 18 months, followed by consecutive monthly payments of principal and interest in arrears starting on March 1, 2018 and continuing through the maturity date of the term loan of August 1, 2020. The Loan Agreement also provides for a floating interest rate (7.95% initially and 9.83% as of December 31, 2018) based on an index rate plus a spread, a $150,000 facility fee that was paid at closing and an additional payment equal to 9.25% of the principal amount of the term loan, which 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 between 1% and 3% of the principal amount of the term loan depending on the timing of prepayment. The facility fee and other debt offering/issuance costs have been recorded as debt discount on the Company’s balance sheet and together with the final $1.9 million payment are being amortized to interest expense during the life of the term loan using the effective interest rate method. 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 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. In February 2018, the Company and Oxford Finance entered into a First Amendment of the Loan Agreement, which modified the terms of the Loan Agreement to change the first principal payment date from March 1, 2018 to December 1, 2018 and to increase the additional payment due when the term loan becomes due or upon the prepayment of the facility from 9.25% of the principal amount of the term loan to 10% of such amount. The interest rate and the maturity date remain unchanged, and the Company paid Oxford Finance a loan modification fee of $100,000. On November 1, 2018, the Company and Oxford Finance entered into a Second Amendment of the Loan Agreement, which modified the terms of the Loan Agreement to change the first principal payment date from December 1, 2018 to June 1, 2020 and the final maturity date from August 1, 2020 to November 1, 2022. 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 interest rate and the final payment remained unchanged, however the Company paid Oxford Finance a Second Amendment fee of $900,000. This amount was recorded as additional debt discount and presented within net non-current portion of term loan on the Company’s balance sheet as of December 31, 2018 and will be amortized as interest expense using the effective interest method over the revised term of the loan. The fair value of the term loan approximates the carrying value. Future maturities and interest payments under the term loan as of December 31, 2018, are as follows (in thousands): 2019 $ 1,612 2020 6,824 2021 8,885 2022 8,912 Total minimum payments 26,233 Less amount representing interest (4,750 ) Gross balance of term loan 21,483 Less unamortized debt discount (950 ) Carrying value of term loan 20,533 Less term loan, current portion, net — Term loan, non-current portion, net $ 20,533

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Common Stock In November 2015, the Company filed a shelf registration statement on Form S-3 with the SEC, which upon being declared effective in November 2015, terminated the December 2013 registration statement and allowed the Company to offer up to $125.0 million of securities from time to time in one or more public offerings of its common stock. In addition, the Company entered into a Controlled Equity Offering sales agreement with Cantor Fitzgerald, under which the Company may sell, subject to certain limitations, up to $40 million of common stock through Cantor Fitzgerald, acting as agent. In 2016, the Company raised net proceeds of approximately $16.1 million (after deducting underwriting discounts and commissions and offering expense) through the sale of approximately 13.8 million shares of its common stock in an underwritten public offering at a price to the public of $1.25 per share and raised net proceeds (net of commissions) of approximately $7.6 million from the sale of approximately 5.2 million shares of its common stock in the open market through the Controlled Equity Offering program with Cantor Fitzgerald at a weighted average price of $1.50 per share. In 2017, the Company raised net proceeds (net of commissions) of approximately $12.0 million from the sale of approximately 8.9 million shares of common stock in the open market through the Controlled Equity Offering program with Cantor Fitzgerald at a weighted average price of $1.39 per share. In 2018, the Company raised net proceeds (net of commissions) of approximately $16.8 million from the sale of approximately 9.6 million shares of common stock in the open market through the Controlled Equity Offering program with Cantor Fitzgerald at a weighted average price of $1.80 per share. 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 the November 2015 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. 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 and June 2016, 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 5,500,000 shares, 4,000,000 shares and 5,000,000 shares, respectively, each of which had previously been approved by the Board of Directors. A total of 33,449,989 shares of common stock have been reserved for issuance under this plan. The plan expires in June 2020. 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 30,000 to 70,000 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. As of December 31, 2018, 9,257,933 shares of common stock were available for future grant and options to purchase 30,217,615 shares of common stock were outstanding under the 2000 Stock Plan. 2000 Directors’ Stock Option Plan In March 2000, the Board of Directors adopted the 2000 Directors’ Stock Option Plan, which provided for the issuance of stock options to non-employee directors of the Company. As of December 31, 2018, options to purchase 100,000 shares of common stock were outstanding under this plan, all of which were vested. The 2000 Directors’ Stock Option Plan expired in September 2000. Grants of stock options to our non-employee directors are made through the 2000 Stock Plan since September 2000. 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 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 250,000 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 350,000 shares; and (ii) extend the term of the ESPP to the date that is ten (10) years following the stockholders meeting. The plan expires in June 2025. A total of 2,900,000 shares of common stock have been reserved for issuance under this plan. As of December 31, 2018, 361,185 shares of common stock were available for future grant and 2,538,815 shares of common stock have been issued under the 2000 Employee Stock Purchase Plan. As of December 31, 2018, shares of common stock reserved for future issuance consisted of the following: December 31, 2018 Stock options outstanding 30,317,615 Stock options available for grant 9,257,933 Employee Stock Purchase Plan 361,185 39,936,733 A summary of stock option activity under all stock-based compensation plans is as follows: Number of Options Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (in Years) Aggregate Intrinsic Value (in millions) Outstanding at December 31, 2017 30,301,405 $ 1.87 5.18 $ 0.4 Options granted 4,267,360 $ 1.31 Options exercised (1,474,441 ) $ 1.11 Options forfeited (672,015 ) $ 1.33 Options expired (2,104,694 ) $ 4.86 Outstanding at December 31, 2018 30,317,615 $ 1.63 5.02 $ — Exercisable at December 31, 2018 27,130,089 $ 1.67 4.65 $ — Vested and expected to vest at December 31, 2018 30,317,615 $ 1.63 5.02 $ — 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 2018 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, 2018. This amount changes based on the fair market value of the Company’s common stock. The total intrinsic value of options exercised was $1.6 million, $328,000 and $158,000 for the years ended December 31, 2018, 2017 and 2016, respectively. In lieu of providing cash bonuses to certain employees, in January 2018, 2017 and 2016, the Company granted its employees stock options to purchase 1.9 million, 1.7 million and 1.4 million shares, respectively, of the Company’s common stock, which vested immediately on the grant date. The weighted-average grant-date fair value of all options granted with exercise prices equal to fair market value was $0.94 in 2018, $0.92 in 2017 and $0.81 in 2016 determined by the Black-Scholes option valuation method. There were no options granted with exercise prices lower than fair market value in 2018, 2017 and 2016. 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, 2018, 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, 2018 2017 2016 Cost of product revenues $ 94 $ 109 $ 106 Research and development 1,549 1,415 1,433 Selling, general and administrative 1,355 1,081 1,116 $ 2,998 $ 2,605 $ 2,655 Because the Company had a net operating loss carryforward as of December 31, 2018, no excess tax benefits for the tax deductions related to stock-based compensation expense were recognized in the statement of operations. Additionally, no incremental tax benefits were recognized from stock options exercised during 2018, 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 (including fully vested options issued in January 2018, 2017 and 2016) and shares purchased under its stock plans and employee stock purchase plan for the years ended December 31, 2018, 2017 and 2016: Year ended December 31, 2018 2017 2016 Stock Options Risk-free rate 2.7-3.1% 2.0-2.5% 1.3-2.4% Expected dividend yield — — — Expected term (in years) 7.0-10.0 6.8-10.0 6.5-10.0 Volatility 78-86% 75-86% 76-83% Forfeiture rate (1) 0.0 % 0.0 % 4.2 % (1) Effective January 1, 2017, the Company elected to account for forfeitures as they occur. Year ended December 31, 2018 2017 2016 Employee Stock Purchase Plan Risk-free rate 1.3-2.5% 0.6-1.3% 0.3-0.6% Expected dividend yield — — — Expected term (in years) 0.5 0.5 0.5 Volatility 60-146% 44-146% 65-81% There were 119,097, 122,033 and 114,025 shares purchased under the Company’s employee stock purchase plan during the years ended December 31, 2018, 2017 and 2016, respectively. Included in the statement of operations and comprehensive loss for the year ended December 31, 2018, 2017 and 2016 was $24,000, $34,000 and $45,000, 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, 2018, $2.5 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 2022. 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, 2018: Options Outstanding Options Exercisable Range of Exercise Price Number of Options Outstanding Weighted- Average Remaining Contractual Life (In years) Weighted- Average Exercise Price Number of Options Exercisable Weighted- Average Exercise Price $0.73 - $0.88 4,574,794 4.80 $ 0.84 4,482,934 $ 0.84 $0.93 - $1.19 3,164,866 6.80 $ 1.15 2,666,690 $ 1.15 $1.20 - $1.20 114,293 5.55 $ 1.20 114,293 $ 1.20 $1.21 - $1.21 3,151,604 4.11 $ 1.21 3,140,354 $ 1.21 $1.24 - $1.24 3,345,280 8.86 $ 1.24 2,101,191 $ 1.24 $1.26 - $1.26 140,000 4.16 $ 1.26 140,000 $ 1.26 $1.31 - $1.31 3,239,274 7.63 $ 1.31 2,275,895 $ 1.31 $1.33 - $2.04 2,171,924 6.79 $ 1.48 2,113,048 $ 1.47 $2.09 - $2.09 3,691,859 3.69 $ 2.09 3,684,734 $ 2.09 $2.10 - $3.61 6,723,721 1.75 $ 2.76 6,410,950 $ 2.79 $0.73 - $3.61 30,317,615 5.02 $ 1.63 27,130,089 $ 1.67 The Company received $1.6 million, $562,000 and $290,000 in cash from option exercises under all stock-based compensation plans for the years ended December 31, 2018, 2017 and 2016, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes The Company accounts for income taxes using the liability method under ASC 740, Income Taxes The reconciliation of income tax expenses (benefit) at the statutory federal income tax rate of 21% for 2018, and 34% for 2017 and 2016, to net income tax benefit included in the statements of operations and comprehensive loss for the years ended December 31, 2018, 2017 and 2016 is as follows (in thousands): Year Ended December 31, 2018 2017 2016 U.S. federal taxes benefit at statutory rate $ (5,318 ) $ (1,307 ) $ (11,733 ) State taxes — 3 — Change in valuation allowance 5,143 (41,865 ) 10,847 Stock-based compensation 999 1,832 2,045 Change in deferred 175 12 (3 ) Deferred Tax Remeasurement 0 42,528 — Other (999 ) (1,353 ) (1,156 ) Total income tax provision (benefit) $ — $ (150 ) $ — In 2018, 2017 and 2016, total income tax provision (benefit) expense was zero, $(150,000) and zero, respectively. The Company has presented these amounts within interest and other income, net in the Statements of Operations and Comprehensive Loss. Deferred tax assets and liabilities reflect the net tax effects of net operating loss and 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, 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 87,275 $ 82,369 Research and other credits 17,524 16,303 Deferred revenue 277 395 Stock-based compensation 4,755 5,053 Other 2,823 2,261 Total deferred tax assets 112,654 106,381 Valuation allowance for deferred tax assets (112,654 ) (106,381 ) Deferred tax liabilities—Intangibles (244 ) (244 ) 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 reduce the provision for income taxes. 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 $6.3 million and $11.4 million during 2018 and 2016, respectively, and decreased by $43.1 million during 2017. As of December 31, 2018, the Company had net operating loss carryforwards for federal income tax purposes of approximately $347.9 million, of which $327.1 million will expire in the years 2019 through 2037, and 20.8 million which do not expire, and federal research and development tax credits of approximately $13.5 million, which expire at various dates beginning in 2019 through 2038, if not utilized. As of December 31, 2018, the Company had net operating loss carryforwards for state income tax purposes of approximately $211.8 million, which expire in the years 2019 through 2038, if not utilized, and state research and development tax credits of approximately $14.6 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, 2018 and December 31, 2017, the Company had unrecognized tax benefits of approximately $8.4 million and $7.8 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, 2018 2017 Balance at beginning of the year $ 7,849 $ 6,982 Decreased related to prior year tax positions (7 ) — Increased related to current year tax positions 590 867 Balance at end of the year $ 8,432 $ 7,849 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 not recognize any interest and penalties expenses related to unrecognized tax benefits for the years ended December 31, 2018, 2017 and 2016. 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 1998 through 2018 due to unutilized net operating losses and research credits. On December 22, 2017, the 2017 Tax Cut and Jobs Act (the Act) was enacted into law and the new legislation contains several key tax provisions, with a primary impact to the Company being a reduction of the corporate income tax rate to 21% effective January 1, 2018. We are required to recognize the effect of the tax law changes in the period of enactment, such as re-measuring our U.S. deferred tax assets and liabilities at a 21% rate as well as reassessing the net realizability of our deferred tax assets and liabilities. The provisional amount related to the re-measurement of our deferred tax balance was estimated to be a reduction of approximately $42.5 million at December 31, 2017. Due to the corresponding valuation allowance fully offsetting deferred taxes, there was no income statement impact. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118) which allows companies to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. Since the Act was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation was yet to be issued, our accounting of the deferred tax re-measurements was incomplete as of December 31, 2017. The 2017 federal corporate income tax return was filed in the fourth quarter of 2018. The final analysis and impact of the Act is reflected in the tax provision and related tax disclosures for the year ended December 31, 2018. There were no material differences to the originally estimated $42.5 million remeasurement of deferred tax assets.

Unaudited Selected Quarterly Fi

Unaudited Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Unaudited Selected Quarterly Financial Data	10. Unaudited Selected Quarterly Financial Data (in thousands, except per share amounts) First Quarter Second Quarter Third Quarter Fourth Quarter 2018 2017 2018 2017 2018 2017 2018 2017 Revenue (1) $ 3,488 $ 4,567 $ 3,413 $ 4,319 $ 8,036 $ 20,746 $ 3,627 $ 19,538 Net income (loss) $ (8,297 ) $ (8,114 ) $ (7,011 ) $ (9,927 ) $ (2,715 ) $ 6,111 $ (7,299 ) $ 8,235 Basic net income (loss) per share $ (0.05 ) $ (0.06 ) $ (0.04 ) $ (0.07 ) $ (0.02 ) $ 0.04 $ (0.05 ) $ 0.06 Diluted net income (loss) per share $ (0.05 ) $ (0.06 ) $ (0.04 ) $ (0.07 ) $ (0.02 ) $ 0.04 $ (0.05 ) $ 0.05 (1) The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	11. Subsequent Events On January 2, 2019, the Company received written notice from Sandoz AG that effective January 27, 2019, Sandoz AG is terminating the Development and Commercialization Agreement, dated May 5, 2017, as amended (the “Sandoz Agreement”). As a result of this termination, Sandoz AG will be returning its exclusive commercialization rights to develop and market POSIMIR® (bupivacaine extended release solution) in the United States. POSIMIR is the Company’s investigational post-operative pain relief depot that utilizes the Company’s patented SABER® technology and is designed to deliver bupivacaine to provide up to three days of pain relief after surgery. The parties are in dispute with regard to Sandoz AG’s obligation to pay a termination fee to the Company. The Company has initiated a formal dispute resolution process related to the termination fee.

Schedule II-Valuation and Quali

Schedule II-Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
Valuation And Qualifying Accounts [Abstract]
Schedule II-Valuation and Qualifying Accounts	SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS Year Ended December 31, 2018, 2017 and 2016 (in thousands) Balance at beginning of the year Additions (Reductions) to allowances Deductions Balance at end of the year Allowance for doubtful accounts Year ended December 31, 2018 $ 155 $ (52 ) $ (1 ) $ 102 Year ended December 31, 2017 $ 73 $ 165 $ (83 ) $ 155 Year ended December 31, 2016 $ 161 $ (70 ) $ (18 ) $ 73

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations DURECT Corporation (the Company) was incorporated in the state of Delaware on February 6, 1998. The Company is a biopharmaceutical company with research and development programs broadly falling into two categories: (i) new chemical entities derived from our Epigenetics Regulator Program, in which the Company attempts to discover and develop molecules which have not previously been approved and marketed as therapeutics, and (ii) Proprietary Pharmaceutical Programs, in which the Company applies its formulation expertise and technologies largely to active pharmaceutical ingredients whose safety and efficacy have previously been established but which the Company aims to improve in some manner through a new formulation. The Company has several products under development by itself and with third party collaborators. The Company also manufactures and sells osmotic pumps used in laboratory research, and designs, develops and manufactures a wide range of standard and custom biodegradable polymers and excipients for pharmaceutical and medical device clients for use as raw materials in their products. In addition, the Company conducts research and development of pharmaceutical products in collaboration with third party pharmaceutical and biotechnology companies.
Basis of Presentation and Use of Estimates	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 deliverables and evaluation of milestones with respect to our collaborations, the amounts of revenues, recoverability of inventory, certain accrued liabilities including accrued clinical trial liability, 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 believe 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.
Reclassifications	Reclassifications Certain prior period amounts on the accompanying Balance Sheets have been reclassified to conform to current period presentation. The Company has reclassified the accretion of final payment of the term loan from other long-term liabilities to net non-current portion of the term loan on the balance sheets as of December 31, 2018 and 2017.
Liquidity and Need to Raise Additional Capital	Liquidity and Need to Raise Additional Capital As of December 31, 2018, the Company has an accumulated deficit of $468.6 million as well as negative cash flows from operating activities. The Company historically has had negative cash flows from operating activities and expects its negative cash flows to continue. The Company will continue to require substantial funds to continue research and development, including clinical trials of its product candidates. Management’s plans in order to meet its operating cash flow requirements include seeking additional collaborative agreements for certain of its programs and achieving milestone and other payments under its collaboration and licensing agreements as well as financing activities such as public offerings and private placements of its common stock, preferred stock offerings, issuances of debt and convertible debt instruments. There are no assurances that such additional funding will be obtained 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.
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.
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 A portion of the Company’s revenue is derived from its ALZET mini pump product line, LACTEL biodegradable polymer product line and the sale of certain excipients for Methydur and one excipient that is included in a currently marketed animal health product. In 2018, revenue from the sale of products from the ALZET product line and the LACTEL product line accounted for 38% and 18% of total revenue, respectively. In 2017, revenue from the ALZET product line and the LACTEL product line accounted for 14% and 12% of total revenue, respectively. In 2016, revenue from the ALZET product line and the LACTEL product line accounted for 51% and 31% of total revenue, respectively. In 2018, Indivior and a pharmaceutical company with which the Company has a feasibility agreement accounted for 27% and 14% of the Company’s total revenues, respectively. In 2017, Sandoz and Indivior accounted for 41% and 25% of the Company’s total revenues, respectively. In 2016, Tolmar accounted for 15% of the Company’s total revenues. Total revenue by geographic region for the years 2018, 2017 and 2016 are as follows (in thousands): Year ended December 31, 2018 2017 2016 Europe $ 8,118 $ 34,261 $ 1,945 United States 7,990 11,323 9,082 Japan 978 1,395 1,413 Others 1,478 2,191 1,585 Total $ 18,564 $ 49,170 $ 14,025 Revenue by geography is determined by the location of the customer.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. Inventories, in part, include certain excipients that are sold to a customer for a currently marketed animal health product and included in several products in development, or awaiting regulatory approval or commercial launch. In October 2017, the Company announced that PERSIST, the Phase 3 clinical trial for POSIMIR, did not meet its primary efficacy endpoint. As a result, the Company wrote down certain lots of inventory which are no longer considered to be probable for use prior to expiration and prepaid inventory related to a minimum purchase agreement for an excipient. In addition, the Company recorded a liability related to a minimum purchase agreement for the same excipient. In 2017, the Company recorded charges to cost of goods sold of approximately $2.0 million, of which approximately $503,000 related to the write-down of the cost basis of inventory on hand, $500,000 related to the prepaid inventory for the minimum purchase commitment for this excipient, and $1.0 million related to the accrual of a liability for the remaining minimum purchase commitment for the same excipient. As of December 31, 2018, the remaining carrying value of the excipient in the Company’s inventory was $68,000. In the event that management determines that the Company will not utilize all of these materials, there could be a potential write-off related to this inventory. If the Company is able to subsequently sell products made with raw materials that were previously written down, the Company will report an unusually high gross profit as there will be no associated cost of goods for these materials. The Company’s inventories consisted of the following (in thousands): December 31, 2018 2017 Raw materials $ 223 $ 282 Work in-process 1,486 1,182 Finished goods 1,712 1,699 Total inventories $ 3,421 $ 3,163
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 at the reporting unit level. 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 expected 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. As of December 31, 2018, the carrying value of goodwill was approximately $6.4 million and no impairment of goodwill has been recorded for any of the periods presented. The Company evaluates goodwill for impairment at least annually. In 2018, 2017 and 2016, goodwill was evaluated and no indicators of impairment were identified. 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, 2018, there have been no material impairment losses.
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. See Note 8 for further information regarding stock-based compensation.
Revenue Recognition	Revenue Recognition The Company enters into license and collaboration agreements under which the Company may receive upfront license fees, research funding and contingent milestone payments and royalties. Prior to January 1, 2018, the Company evaluated the accounting treatment under these agreements including whether multiple deliverables existed, how the deliverables should be separated and how the consideration should be allocated to one or more units of accounting. For the Company’s collaborations with multiple deliverables, the Company had concluded that the deliverables were not separable and the arrangements should be accounted for as a combined unit of accounting. As a combined unit of accounting, the Company recognized the consideration for the combined unit of accounting in the same manner as the revenue was recognized for the final deliverable, which was generally ratably over the longest period of involvement. For example, upfront payments received upon execution of collaborative agreements were recorded as deferred revenue and recognized as collaborative research and development revenue based on a straight-line basis over the period of the Company’s continuing involvement with the third-party collaborator pursuant to the applicable agreement. Such period generally represented the longer of the estimated research and development period or other continuing obligation period defined in the respective agreements between the Company and its third-party collaborators. If the Company determined that the expected timeline for a project and therefore the Company’s continuing involvement was materially different than we previously assumed, the Company adjusted the period over which it recognized the deferred revenue. Effective January 1, 2018, the Company adopted FASB ASC Topic 606, Revenue from Contracts with Customers, or ASC 606. In accordance with ASC 606, the Company changed certain characteristics of its revenue recognition accounting policy as described below. ASC 606 was applied using the modified retrospective method, where the cumulative effect of the initial application was recognized as an adjustment to opening retained earnings at January 1, 2018. Therefore, comparative prior periods have not been adjusted and continue to be reported under FASB ASC Topic 605, Revenue Recognition, or ASC 605. The Company recorded a net increase to opening accumulated deficit of $470,000 with a corresponding entry to deferred revenue as of January 1, 2018 due to the cumulative impact of adopting Topic 606, with the impact relating to a reduction in the Company’s deferred collaborative research and development revenues. There was no impact to reported total assets, revenues and operating expenses for the twelve months ended December 31, 2018 as a result of applying Topic 606. Product Revenue, Net The Company sells osmotic pumps used in laboratory research, and designs, develops and manufactures a wide range of standard and custom biodegradable polymers and excipients for pharmaceutical and medical device clients for use as raw materials in their products. Revenues from product sales are recognized when the customer obtains control of the Company’s product, which occurs at a point in time, typically upon shipment to the customer. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less. Trade Discounts and Allowances: The Company provides certain customers with discounts that are explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized. Product Returns: Consistent with industry practice, the Company generally offers customers a limited right of return for products that have been purchased from the Company. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using its historical sales information. The Company expects product returns to be minimal. Collaborative Research and Development Revenues The Company enters into license agreements which are within the scope of Topic 606, under which it licenses certain rights to its product candidates to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees; reimbursement of development costs incurred by the Company under approved work plans; development, regulatory and commercial milestone payments; payments for manufacturing supply services the Company provides through its contract manufacturers; and royalties on net sales of licensed products. Each of these payments results in collaborative research and development revenues, except for revenues from royalties on net sales of licensed products, which are classified as royalty revenues. In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the standalone selling price, which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. The Company expects to recognize revenue for the variable consideration currently being constrained when it is probable that a significant revenue reversal will not occur. Licenses of intellectual property: If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments: At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaborative research and development revenues and net income (loss) in the period of adjustment. Manufacturing Supply Services: Arrangements that include a promise for future supply of drug product for either clinical development or commercial supply at the customer’s discretion are generally considered as options. The Company assesses if these options provide a material right to the customer and if so, they are accounted for as separate performance obligations. If the Company is entitled to additional payments when the customer exercises these options, any additional payments are recorded in collaborative research and development revenue when the customer obtains control of the goods, which is upon delivery. Royalties and Earn-outs: For arrangements that include sales-based royalties or earn-outs, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any significant royalty revenue resulting from the Company’s collaborative arrangements or any earn-out revenue from the Company’s patent purchase agreement with Indivior. The cumulative effect of the changes made to the Company’s January 1, 2018 balance sheet for the adoption of ASC 606 Revenue – Revenue from Contract with Customers was as follows (in thousands): Balance at December 31, 2017 Adjustments Due to ASC 606 Balance at January 1, 2018 Balance Sheet Liabilities Deferred revenue, non-current portion $ 1,093 $ 470 $ 623 Equity Accumulated deficit $ (443,772 ) $ 470 $ (443,302 ) During the twelve months ended December 31, 2018, the Company did not recognize any revenue as a result of changes in the contract asset and the contract liability balances associated with the Company’s deferred research and development revenues for the Company’s collaboration agreements as a result of adoption of ASC 606. In accordance with the new revenue standard requirements, the disclosure of the impact of adoption on balance sheet, statement of operations and comprehensive loss, and statement of cash flows for the twelve months ended December 31, 2018 was as follows (in thousands): As of December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Balance Sheet Liabilities Deferred revenue, non-current portion $ 812 $ 1,282 $ (470 ) For the year ended December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Statement of Operations and Comprehensive Loss Collaborative research and development and other revenue $ 8,207 $ 8,207 $ - Product revenue, net 10,357 10,357 - Total revenues $ 18,564 $ 18,564 $ - For the year ended December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Statement of Cash Flows Cash flow from Operating Activities Deferred revenue, non-current portion $ (493 ) $ (23 ) $ (470 )
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, reimbursements of research and development expenses incurred 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 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, 2018 2017 2016 Numerators: Net loss $ (25,322 ) $ (3,695 ) $ (34,509 ) Denominators: Weighted average shares used to compute basic net loss per share 159,834 145,273 133,163 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute diluted net loss per share 159,834 145,273 133,163 Net loss per share: Basic $ (0.16 ) $ (0.03 ) $ (0.26 ) Diluted $ (0.16 ) $ (0.03 ) $ (0.26 ) The computation of diluted net loss per share for the years ended 2018, 2017 and 2016 excludes the impact of options to purchase 16.6 million, 20.1 million and 18.7 million shares of common stock outstanding, respectively, at December 31, 2018, 2017 and 2016, 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.
Operating Leases	Operating Leases The Company leases administrative, manufacturing and laboratory facilities under operating leases. Lease agreements may include rent holidays, rent escalation clauses and tenant improvement allowances. The Company recognizes scheduled rent increases on a straight-line basis over the lease term beginning with the date the Company takes possession of the leased space. The Company records tenant improvement allowances as deferred rent liabilities and amortizes the deferred rent over the terms of the lease to rent expense on the statements of operations and comprehensive loss.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2018, the FASB issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates certain disclosure requirements for fair value measurements for all entities, requires public entities to disclose certain new information and modifies some disclosure requirements. This standard is effective for fiscal years beginning after December 15, 2019, including interim reporting periods within those years, with early adoption permitted. The Company does not expect the adoption of this standard to have a material effect on its financial statements. In June 2018, the FASB issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation – Stock Compensation (Topic 718), which expands the scope of ASC 718 to include all share-based payment arrangements related to the acquisition of goods and services from both nonemployees and employees. Under the new standard, most of the guidance on stock compensation payments to nonemployees would be aligned with the requirements for share-based payments granted to employees. This standard is effective for fiscal years beginning after December 15, 2018, including interim reporting periods within those years, with early adoption permitted. The Company does not expect the adoption of this standard to have a material effect on its financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Commitments,

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Summary of Total Revenue by Geographic Region	Total revenue by geographic region for the years 2018, 2017 and 2016 are as follows (in thousands): Year ended December 31, 2018 2017 2016 Europe $ 8,118 $ 34,261 $ 1,945 United States 7,990 11,323 9,082 Japan 978 1,395 1,413 Others 1,478 2,191 1,585 Total $ 18,564 $ 49,170 $ 14,025
Summary of Components of Inventories	The Company’s inventories consisted of the following (in thousands): December 31, 2018 2017 Raw materials $ 223 $ 282 Work in-process 1,486 1,182 Finished goods 1,712 1,699 Total inventories $ 3,421 $ 3,163
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, 2018 2017 2016 Numerators: Net loss $ (25,322 ) $ (3,695 ) $ (34,509 ) Denominators: Weighted average shares used to compute basic net loss per share 159,834 145,273 133,163 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute diluted net loss per share 159,834 145,273 133,163 Net loss per share: Basic $ (0.16 ) $ (0.03 ) $ (0.26 ) Diluted $ (0.16 ) $ (0.03 ) $ (0.26 )
Accounting Standards Update 2014-09
Schedule of Cumulative Effect of Changes made to Balance Sheet for Adoption of ASC 606	The cumulative effect of the changes made to the Company’s January 1, 2018 balance sheet for the adoption of ASC 606 Revenue – Revenue from Contract with Customers was as follows (in thousands): Balance at December 31, 2017 Adjustments Due to ASC 606 Balance at January 1, 2018 Balance Sheet Liabilities Deferred revenue, non-current portion $ 1,093 $ 470 $ 623 Equity Accumulated deficit $ (443,772 ) $ 470 $ (443,302 )
Schedule of Impact of Adoption with New Revenue Standard Requirements on Financial Statements	In accordance with the new revenue standard requirements, the disclosure of the impact of adoption on balance sheet, statement of operations and comprehensive loss, and statement of cash flows for the twelve months ended December 31, 2018 was as follows (in thousands): As of December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Balance Sheet Liabilities Deferred revenue, non-current portion $ 812 $ 1,282 $ (470 ) For the year ended December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Statement of Operations and Comprehensive Loss Collaborative research and development and other revenue $ 8,207 $ 8,207 $ - Product revenue, net 10,357 10,357 - Total revenues $ 18,564 $ 18,564 $ - For the year ended December 31, 2018 As reported Balances without adoption of ASC 606 Effect of change Higher/(Lower) Statement of Cash Flows Cash flow from Operating Activities Deferred revenue, non-current portion $ (493 ) $ (23 ) $ (470 )

Strategic Agreements (Tables)

Strategic Agreements (Tables)	12 Months Ended
	Dec. 31, 2018
Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators	The collaborative research and development and other revenues associated with the Company’s major third-party collaborators are as follows (in thousands): Year ended December 31, 2018 2017 2016 Collaborator/Counterparty Indivior UK Limited (Indivior) (1) $ 5,019 $ — $ — Santen Pharmaceutical Co. Ltd. (Santen) (2) 102 294 514 Sandoz AG (Sandoz) (3) — 20,000 — Zogenix, Inc. (Zogenix) (4) — 835 555 Pain Therapeutics, Inc. (Pain Therapeutics) — 109 670 Other (5) 3,086 2,339 141 Total collaborative research and development and other revenue $ 8,207 $ 23,577 $ 1,880 (1) Amount consists of a $5.0 million milestone payment earned from Indivior upon NDA approval of PERSERIS in 2018 and earn-out revenue from PERSERIS net sales compared with zero in 2017 and 2016; we and Indivior signed a license agreement effective July 2017. ( 2 ) Amounts related to recognition of upfront fees were zero in 2018, $199,000 in 2017, and $228,000 in 2016. The Company and Santen signed a license agreement effective December 2014. In January 2018, the Company was notified by Santen that due to a shift in near term priorities, Santen has elected to reallocate research and development resources and put the Company’s program on pause until further notice. While the main program is on pause, the parties are working together on a limited set of research and development activities funded by Santen. ( 3 ) Amounts related to recognition of upfront fees were zero in 2018, $20.0 million in 2017 and zero in 2016; the Company and Sandoz signed a license agreement effective June 2017. As of December 31, 2017, all of the $20.0 million upfront fee had been recognized as revenue as the Company’s contractual performance obligations had been fulfilled. In January 2019, the license agreement was terminated. ( 4 ) Amounts related to ratable recognition of upfront fees were zero in 2018, $833,000 in 2017, and $208,000 in 2016. The Company and Zogenix signed a license agreement effective July 2011. In August 2017, the Company and Zogenix terminated their Development and License Agreement dated July 11, 2011 relating to the development and commercialization of Relday. ( 5 ) Includes revenue recognized associated with the Company’s feasibility agreements for years ended December 31, 2018, 2017 and 2016.
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Summary of Collaborative Research and Development Revenue Recognized	The following table provides a summary of collaborative research and development revenue recognized under the Santen Agreement (in thousands). Year Ended December 31, 2018 2017 2016 Ratable recognition of upfront payment $ — $ 199 $ 228 Research and development expenses reimbursable by Santen 102 95 286 Total collaborative research and development revenue $ 102 $ 294 $ 514
Agreement with Zogenix, Inc. [Member]
Summary of Collaborative Research and Development Revenue Recognized	The following table provides a summary of collaborative research and development revenue recognized under the agreements with Zogenix (in thousands). The cumulative aggregate payments received by the Company as of December 31, 2018 were $20.1 million under these agreements. Year Ended December 31, 2018 2017 2016 Ratable recognition of upfront payment $ — $ 833 $ 208 Research and development expenses reimbursable by Zogenix — 2 347 Total collaborative research and development revenue $ — $ 835 $ 555

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 502 $ — $ — $ 502 Certificates of deposit — 150 — 150 Commercial paper — 32,224 — 32,224 Total $ 502 $ 32,374 $ — $ 32,876 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, 2017 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 568 $ — $ — $ 568 Certificates of deposit — 150 — 150 Commercial paper — 33,307 — 33,307 Corporate debt — 1,297 — 1,297 Total $ 568 $ 34,754 $ — $ 35,322
Summary of Money Market Funds and Available-for-Sale Securities	The following is a summary of available-for-sale securities as of December 31, 2018 and 2017 (in thousands): December 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 502 $ — $ — $ 502 Certificates of deposit 150 — — 150 Commercial paper 32,224 — — 32,224 $ 32,876 $ — $ — $ 32,876 Reported as: Cash and cash equivalents $ 30,055 $ — $ — $ 30,055 Short-term investments 2,671 — — 2,671 Long-term restricted investments 150 — — 150 $ 32,876 $ — $ — $ 32,876 December 31, 2017 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Money market funds $ 568 $ — $ — $ 568 Certificates of deposit 150 — — 150 Commercial paper 33,307 — — 33,307 Corporate debt 1,298 — (1 ) 1,297 $ 35,323 $ — $ (1 ) $ 35,322 Reported as: Cash and cash equivalents $ 27,788 $ — $ — $ 27,788 Short-term investments 7,385 — (1 ) 7,384 Long-term restricted investments 150 — — 150 $ 35,323 $ — $ (1 ) $ 35,322
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, 2018, by contractual maturity (in thousands): December 31, 2018 Amortized Cost Estimated Fair Value Mature in one year or less $ 32,374 $ 32,374 $ 32,374 $ 32,374

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	Property and equipment consist of the following (in thousands): December 31, 2018 2017 Equipment $ 12,785 $ 12,688 Leasehold improvement 9,828 9,929 Construction-in-progress 33 119 22,646 22,736 Less accumulated depreciation and amortization (22,041 ) (21,807 ) Property and equipment, net $ 605 $ 929

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2018
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) Birmingham, AL 21,540 sq. ft. Office, Laboratory and Manufacturing Lease expires 2021 (with two options to renew the lease term for an additional five years each after the current lease expires)
Schedule of Future Operating Lease Minimum Payments	Future minimum payments under these noncancelable leases are as follows (in thousands): Year ending December 31, Operating Leases 2019 $ 2,122 2020 2,200 2021 2,126 2022 1,991 2023 and thereafter 2,245 $ 10,684

Term Loan (Tables)

Term Loan (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Future Maturities and Interest Payments under Term Loan	Future maturities and interest payments under the term loan as of December 31, 2018, are as follows (in thousands): 2019 $ 1,612 2020 6,824 2021 8,885 2022 8,912 Total minimum payments 26,233 Less amount representing interest (4,750 ) Gross balance of term loan 21,483 Less unamortized debt discount (950 ) Carrying value of term loan 20,533 Less term loan, current portion, net — Term loan, non-current portion, net $ 20,533

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Summary of Shares of Common Stock Reserved for Future Issuance	As of December 31, 2018, shares of common stock reserved for future issuance consisted of the following: December 31, 2018 Stock options outstanding 30,317,615 Stock options available for grant 9,257,933 Employee Stock Purchase Plan 361,185 39,936,733
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 Options Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (in Years) Aggregate Intrinsic Value (in millions) Outstanding at December 31, 2017 30,301,405 $ 1.87 5.18 $ 0.4 Options granted 4,267,360 $ 1.31 Options exercised (1,474,441 ) $ 1.11 Options forfeited (672,015 ) $ 1.33 Options expired (2,104,694 ) $ 4.86 Outstanding at December 31, 2018 30,317,615 $ 1.63 5.02 $ — Exercisable at December 31, 2018 27,130,089 $ 1.67 4.65 $ — Vested and expected to vest at December 31, 2018 30,317,615 $ 1.63 5.02 $ —
Summary of Employee Stock-Based Compensation Cost that has been Included in Statements of Operations and Comprehensive Loss	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, 2018 2017 2016 Cost of product revenues $ 94 $ 109 $ 106 Research and development 1,549 1,415 1,433 Selling, general and administrative 1,355 1,081 1,116 $ 2,998 $ 2,605 $ 2,655
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 (including fully vested options issued in January 2018, 2017 and 2016) and shares purchased under its stock plans and employee stock purchase plan for the years ended December 31, 2018, 2017 and 2016: Year ended December 31, 2018 2017 2016 Stock Options Risk-free rate 2.7-3.1% 2.0-2.5% 1.3-2.4% Expected dividend yield — — — Expected term (in years) 7.0-10.0 6.8-10.0 6.5-10.0 Volatility 78-86% 75-86% 76-83% Forfeiture rate (1) 0.0 % 0.0 % 4.2 % (1) Effective January 1, 2017, the Company elected to account for forfeitures as they occur. Year ended December 31, 2018 2017 2016 Employee Stock Purchase Plan Risk-free rate 1.3-2.5% 0.6-1.3% 0.3-0.6% Expected dividend yield — — — Expected term (in years) 0.5 0.5 0.5 Volatility 60-146% 44-146% 65-81%
Summary of Stock Options Outstanding	The following table summarizes information about stock options outstanding at December 31, 2018: Options Outstanding Options Exercisable Range of Exercise Price Number of Options Outstanding Weighted- Average Remaining Contractual Life (In years) Weighted- Average Exercise Price Number of Options Exercisable Weighted- Average Exercise Price $0.73 - $0.88 4,574,794 4.80 $ 0.84 4,482,934 $ 0.84 $0.93 - $1.19 3,164,866 6.80 $ 1.15 2,666,690 $ 1.15 $1.20 - $1.20 114,293 5.55 $ 1.20 114,293 $ 1.20 $1.21 - $1.21 3,151,604 4.11 $ 1.21 3,140,354 $ 1.21 $1.24 - $1.24 3,345,280 8.86 $ 1.24 2,101,191 $ 1.24 $1.26 - $1.26 140,000 4.16 $ 1.26 140,000 $ 1.26 $1.31 - $1.31 3,239,274 7.63 $ 1.31 2,275,895 $ 1.31 $1.33 - $2.04 2,171,924 6.79 $ 1.48 2,113,048 $ 1.47 $2.09 - $2.09 3,691,859 3.69 $ 2.09 3,684,734 $ 2.09 $2.10 - $3.61 6,723,721 1.75 $ 2.76 6,410,950 $ 2.79 $0.73 - $3.61 30,317,615 5.02 $ 1.63 27,130,089 $ 1.67

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
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% for 2018, and 34% for 2017 and 2016, to net income tax benefit included in the statements of operations and comprehensive loss for the years ended December 31, 2018, 2017 and 2016 is as follows (in thousands): Year Ended December 31, 2018 2017 2016 U.S. federal taxes benefit at statutory rate $ (5,318 ) $ (1,307 ) $ (11,733 ) State taxes — 3 — Change in valuation allowance 5,143 (41,865 ) 10,847 Stock-based compensation 999 1,832 2,045 Change in deferred 175 12 (3 ) Deferred Tax Remeasurement 0 42,528 — Other (999 ) (1,353 ) (1,156 ) Total income tax provision (benefit) $ — $ (150 ) $ —
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, 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 87,275 $ 82,369 Research and other credits 17,524 16,303 Deferred revenue 277 395 Stock-based compensation 4,755 5,053 Other 2,823 2,261 Total deferred tax assets 112,654 106,381 Valuation allowance for deferred tax assets (112,654 ) (106,381 ) Deferred tax liabilities—Intangibles (244 ) (244 ) 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, 2018 2017 Balance at beginning of the year $ 7,849 $ 6,982 Decreased related to prior year tax positions (7 ) — Increased related to current year tax positions 590 867 Balance at end of the year $ 8,432 $ 7,849

Unaudited Selected Quarterly _2

Unaudited Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	First Quarter Second Quarter Third Quarter Fourth Quarter 2018 2017 2018 2017 2018 2017 2018 2017 Revenue (1) $ 3,488 $ 4,567 $ 3,413 $ 4,319 $ 8,036 $ 20,746 $ 3,627 $ 19,538 Net income (loss) $ (8,297 ) $ (8,114 ) $ (7,011 ) $ (9,927 ) $ (2,715 ) $ 6,111 $ (7,299 ) $ 8,235 Basic net income (loss) per share $ (0.05 ) $ (0.06 ) $ (0.04 ) $ (0.07 ) $ (0.02 ) $ 0.04 $ (0.05 ) $ 0.06 Diluted net income (loss) per share $ (0.05 ) $ (0.06 ) $ (0.04 ) $ (0.07 ) $ (0.02 ) $ 0.04 $ (0.05 ) $ 0.05 (1) The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) shares in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2018USD ($)

Sep. 30, 2018USD ($)

[1]

Jun. 30, 2018USD ($)

[1]

Mar. 31, 2018USD ($)

[1]

Dec. 31, 2017USD ($)

Sep. 30, 2017USD ($)

[1]

Jun. 30, 2017USD ($)

[1]

Mar. 31, 2017USD ($)

[1]

Dec. 31, 2018USD ($)Segmentshares

Dec. 31, 2017USD ($)shares

Dec. 31, 2016USD ($)shares

Jan. 01, 2019USD ($)

Jan. 01, 2018USD ($)

Summary Of Significant Accounting Policies [Line Items]

State of incorporation

Delaware

Date of incorporation

Feb. 6, 1998

Accumulated deficit

$ 468,624,000

$ 443,772,000

$ 468,624,000

$ 443,772,000

Highly liquid investments maturity period

90 days or less

Long-term investments maturity period

One year or beyond

Realized gains or losses on cash, cash equivalents and investments

$ 0

0

Cost of goods sold

4,263,000

6,633,000

$ 5,290,000

Write-down of the cost basis of inventory on hand

291,000

2,259,000

687,000

Minimum purchase commitment

500,000

Inventories

3,421,000

3,163,000

$ 3,421,000

3,163,000

Number of operating segment | Segment

1

Number of reporting segment | Segment

1

Goodwill

6,399,000

6,399,000

$ 6,399,000

6,399,000

Goodwill impairment

0

0

0

Long-lived assets, impairment losses

0

Revenue recognized as a result of changes in the contract asset and the contract liability balances

3,627,000

[1]

$ 8,036,000

$ 3,413,000

$ 3,488,000

$ 19,538,000

[1]

$ 20,746,000

$ 4,319,000

$ 4,567,000

$ 18,564,000

$ 49,170,000

$ 14,025,000

Options to purchase common stock excluded from computation of diluted net loss per share | shares

16.6

20.1

18.7

Recognize additional lease liabilities

$ 7,700,000

Right-of-use assets

$ 7,300,000

Accounting Standards Update 2014-09

Summary Of Significant Accounting Policies [Line Items]

Accumulated deficit

$ 443,302,000

Increase in retained earnings due to cumulative impact of adopting Topic 606

$ 470,000

Agreement with Pain Therapeutics, Inc. [Member]

Summary Of Significant Accounting Policies [Line Items]

Revenue recognized as a result of changes in the contract asset and the contract liability balances

$ 0

$ 109,000

$ 670,000

Agreement with Pain Therapeutics, Inc. [Member] | PERSIST, Phase 3 Clinical Trial for POSIMIR [Member]

Summary Of Significant Accounting Policies [Line Items]

Cost of goods sold

2,000,000

Write-down of the cost basis of inventory on hand

503,000

Minimum purchase commitment

1,000,000

Inventories

$ 68,000

68,000

Agreement with Pain Therapeutics, Inc. [Member] | PERSIST, Phase 3 Clinical Trial for POSIMIR [Member] | Prepaid Inventory [Member]

Summary Of Significant Accounting Policies [Line Items]

Minimum purchase commitment

$ 500,000

Collaborative Research and Development Revenue [Member] | Accounting Standards Update 2014-09

Summary Of Significant Accounting Policies [Line Items]

Revenue recognized as a result of changes in the contract asset and the contract liability balances

$ 0

Sales Revenue Net [Member] | Customer Concentration Risk [Member] | Customer With Feasibility Agreement [Member]

Summary Of Significant Accounting Policies [Line Items]

Percentage of revenue accounted in Company's total revenue

14.00%

Sales Revenue Net [Member] | Customer Concentration Risk [Member] | Sandoz [Member]

Summary Of Significant Accounting Policies [Line Items]

Percentage of revenue accounted in Company's total revenue

41.00%

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

27.00%

25.00%

Sales Revenue Net [Member] | Customer Concentration Risk [Member] | Tolmar Inc. [Member]

Summary Of Significant Accounting Policies [Line Items]

Percentage of revenue accounted in Company's total revenue

15.00%

Sales Revenue Net [Member] | ALZET Product Line [Member] | Product Concentration Risk [Member]

Summary Of Significant Accounting Policies [Line Items]

Percentage of revenue accounted in Company's total revenue

38.00%

14.00%

51.00%

Sales Revenue Net [Member] | LACTEL Product Line [Member] | Product Concentration Risk [Member]

Summary Of Significant Accounting Policies [Line Items]

Percentage of revenue accounted in Company's total revenue

18.00%

12.00%

31.00%

Minimum [Member]

Summary Of Significant Accounting Policies [Line Items]

Short-term investments maturity period

90 days

Property and equipment, estimated useful life

3 years

Operating lease assets and liabilities recognition period

12 months

Maximum [Member]

Summary Of Significant Accounting Policies [Line Items]

Short-term investments maturity period

1 year

Property and equipment, estimated useful life

5 years

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Total Revenue by Geographic Region (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2018

[1]

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Dec. 31, 2017

[1]

Sep. 30, 2017

[1]

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue

$ 3,627

$ 8,036

$ 3,413

$ 3,488

$ 19,538

$ 20,746

$ 4,319

$ 4,567

$ 18,564

$ 49,170

$ 14,025

Europe [Member]

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue

8,118

34,261

1,945

United States [Member]

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue

7,990

11,323

9,082

Japan [Member]

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue

978

1,395

1,413

Others [Member]

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue

$ 1,478

$ 2,191

$ 1,585

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Components of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Inventory Net [Abstract]
Raw materials	$ 223	$ 282
Work in-process	1,486	1,182
Finished goods	1,712	1,699
Total inventories	$ 3,421	$ 3,163

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Schedule of Cumulative Effect of Changes made to Balance Sheet for Adoption of ASC 606 (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Liabilities
Deferred revenue, non-current portion	$ 812		$ 1,093
Stockholders’ equity:
Accumulated deficit	(468,624)		$ (443,772)
Accounting Standards Update 2014-09
Liabilities
Deferred revenue, non-current portion		$ 623
Stockholders’ equity:
Accumulated deficit		(443,302)
Adjustments Due to ASC 606 | Accounting Standards Update 2014-09
Liabilities
Deferred revenue, non-current portion	$ (470)	470
Stockholders’ equity:
Accumulated deficit		$ 470

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Impact of Adoption with New Revenue Standard Requirements on Financial Statements (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2018

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Dec. 31, 2017

Sep. 30, 2017

[1]

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Jan. 01, 2018

Liabilities

Deferred revenue, non-current portion

$ 812

$ 1,093

$ 812

$ 1,093

Total revenues

3,627

[1]

$ 8,036

$ 3,413

$ 3,488

$ 19,538

[1]

$ 20,746

$ 4,319

$ 4,567

18,564

49,170

$ 14,025

Cash flows from operating activities

Deferred revenue

(493)

(1,072)

(38)

Collaborative Research and Development and Other Revenue [Member]

Liabilities

Total revenues

8,207

23,577

1,880

Product Revenue, Net [Member]

Liabilities

Total revenues

10,357

$ 13,093

$ 12,145

Accounting Standards Update 2014-09

Liabilities

Deferred revenue, non-current portion

$ 623

Balances without adoption of ASC 606 | Accounting Standards Update 2014-09

Liabilities

Deferred revenue, non-current portion

1,282

1,282

Total revenues

18,564

Cash flows from operating activities

Deferred revenue

(23)

Balances without adoption of ASC 606 | Accounting Standards Update 2014-09 | Collaborative Research and Development and Other Revenue [Member]

Liabilities

Total revenues

8,207

Balances without adoption of ASC 606 | Accounting Standards Update 2014-09 | Product Revenue, Net [Member]

Liabilities

Total revenues

10,357

Effect of change Higher/(Lower) | Accounting Standards Update 2014-09

Liabilities

Deferred revenue, non-current portion

$ (470)

(470)

$ 470

Cash flows from operating activities

Deferred revenue

$ (470)

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Summary of Significant Accoun_9

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	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerators:
Net loss	$ (7,299)	$ (2,715)	$ (7,011)	$ (8,297)	$ 8,235	$ 6,111	$ (9,927)	$ (8,114)	$ (25,322)	$ (3,695)	$ (34,509)
Denominators:
Weighted average shares used to compute basic net loss per share									159,834	145,273	133,163
Effect of dilutive securities:
Dilution from stock options									0	0	0
Dilution from ESPP									0	0	0
Dilutive common shares									0	0	0
Weighted average shares used to compute diluted net loss per share									159,834	145,273	133,163
Net loss per share:
Basic	$ (0.05)	$ (0.02)	$ (0.04)	$ (0.05)	$ 0.06	$ 0.04	$ (0.07)	$ (0.06)	$ (0.16)	$ (0.03)	$ (0.26)
Diluted	$ (0.05)	$ (0.02)	$ (0.04)	$ (0.05)	$ 0.05	$ 0.04	$ (0.07)	$ (0.06)	$ (0.16)	$ (0.03)	$ (0.26)

Strategic Agreements - Summary

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2018

[1]

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Dec. 31, 2017

[1]

Sep. 30, 2017

[1]

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

$ 3,627

$ 8,036

$ 3,413

$ 3,488

$ 19,538

$ 20,746

$ 4,319

$ 4,567

$ 18,564

$ 49,170

$ 14,025

Agreement with Pain Therapeutics, Inc. [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

0

109

670

Collaborative Research and Development and Other Revenue [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

8,207

23,577

1,880

Collaborative Research and Development and Other Revenue [Member] | Patent Purchase Agreement with Indivior [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

5,019

Collaborative Research and Development and Other Revenue [Member] | Agreement with Santen Pharmaceutical Co., Ltd. [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

102

294

514

Collaborative Research and Development and Other Revenue [Member] | Agreement with Sandoz AG [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

20,000

Collaborative Research and Development and Other Revenue [Member] | Agreement with Zogenix, Inc. [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

835

555

Collaborative Research and Development and Other Revenue [Member] | Agreement with Pain Therapeutics, Inc. [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

109

670

Collaborative Research and Development and Other Revenue [Member] | Agreements With Other Collaborators or Counterparties [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue

$ 3,086

$ 2,339

$ 141

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

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 ($) $ in Thousands	Aug. 31, 2017	Dec. 11, 2014	Dec. 31, 2017	May 31, 2017	Dec. 31, 2018	[1]	Sep. 30, 2018		Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017	[1]	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues					$ 3,627		$ 8,036	[1]	$ 3,413		$ 3,488		$ 19,538	[1]	$ 20,746	[1]	$ 4,319	[1]	$ 4,567		$ 18,564	$ 49,170	$ 14,025
Patent Purchase Agreement with Indivior [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amount related to the milestone payment earned							$ 5,000														5,000	0	0
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amounts related to the ratable recognition of upfront fees																					0	199	228
Agreement with Santen Pharmaceutical Co., Ltd. [Member] | License Fees [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues		$ 2,000
Agreement with Sandoz AG [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amounts related to the ratable recognition of upfront fees													$ 15,400		3,800		$ 800				$ 0	20,000	0
Agreement termination month and year																					2019-01
Agreement with Sandoz AG [Member] | License Fees [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues			$ 20,000	$ 20,000																		20,000
Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amounts related to the ratable recognition of upfront fees															$ 750						$ 0	$ 833	$ 208
Agreement termination month and year	2017-08
[1]	The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Strategic Agreements - Addition

Strategic Agreements - Additional Information (Detail) - Subsequent Event [Member]	Mar. 04, 2019USD ($)	Mar. 04, 2019USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments received	$ 0	$ 0
Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments	77,500,000
Early stage clinical testing [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones	2,000,000	2,000,000
Late stage clinical testing [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones	3,000,000	3,000,000
Regulatory filings [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones	3,000,000	3,000,000
Regulatory approvals [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones	6,500,000	$ 6,500,000
Development-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments	14,500,000
Sales-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments	$ 63,000,000

Strategic Agreements - Patent P

Strategic Agreements - Patent Purchase Agreement with Indivior - Additional Information (Detail) - USD ($) $ in Thousands

Sep. 26, 2017

Sep. 30, 2017

Dec. 31, 2018

[1]

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Dec. 31, 2017

[1]

Sep. 30, 2017

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Jul. 27, 2018

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 3,627

$ 8,036

$ 3,413

$ 3,488

$ 19,538

$ 20,746

[1]

$ 4,319

$ 4,567

$ 18,564

$ 49,170

$ 14,025

Intellectual Property Rights [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

12,500

Patent Purchase Agreement with Indivior [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Upfront non-refundable payment received

$ 12,500

$ 12,500

Granted patents extending year, minimum

2,026

Earn-out revenue recognized

19

Patent Purchase Agreement with Indivior [Member] | Intellectual Property Rights [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 12,500

$ 12,500

Patent Purchase Agreement with Indivior [Member] | Regulatory Based Milestone [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Performance milestone payments based on successful development

$ 5,000

$ 5,000

Revenue recognition milestone achieved

$ 5,000

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Strategic Agreements - Agreemen

Strategic Agreements - Agreement with Pain Therapeutics, Inc. - Additional Information (Detail)	1 Months Ended	3 Months Ended																12 Months Ended
	Dec. 31, 2002Drug	Dec. 31, 2018USD ($)		Sep. 30, 2018USD ($)	[1]	Jun. 30, 2018USD ($)	[1]	Mar. 31, 2018USD ($)	[1]	Dec. 31, 2017USD ($)	[1]	Sep. 30, 2017USD ($)	[1]	Jun. 30, 2017USD ($)	[1]	Mar. 31, 2017USD ($)	[1]	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues		$ 3,627,000	[1]	$ 8,036,000		$ 3,413,000		$ 3,488,000		$ 19,538,000		$ 20,746,000		$ 4,319,000		$ 4,567,000		$ 18,564,000	$ 49,170,000	$ 14,025,000
Cost of goods sold																		4,263,000	6,633,000	5,290,000
Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues																		10,357,000	13,093,000	12,145,000
Agreement with Pain Therapeutics, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of specified opioid drugs | Drug	4
Total revenues																		0	109,000	670,000
Performance milestone payments based on successful development		3,000,000																3,000,000
Revenue recognition milestone achieved																		1,500,000
Cumulative aggregate payments received by the Company																		40,400,000
Agreement with Pain Therapeutics, Inc. [Member] | License Fees [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues																		1,000,000
Agreement with Pain Therapeutics, Inc. [Member] | Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues																		0	0	653,000
Cost of goods sold																		0	$ 0	$ 216,000
Agreement with Pain Therapeutics, Inc. [Member] | Development-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Performance milestone payments based on successful development		3,000,000																3,000,000
Agreement with Pain Therapeutics, Inc. [Member] | Sales-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Performance milestone payments based on successful development		$ 0																$ 0
[1]	The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Strategic Agreements - Agreem_2

Strategic Agreements - Agreement with Santen Pharmaceutical Co., Ltd. - Additional Information (Detail) - USD ($)

Dec. 11, 2014

Dec. 31, 2018

[1]

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Dec. 31, 2017

[1]

Sep. 30, 2017

[1]

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 3,627,000

$ 8,036,000

$ 3,413,000

$ 3,488,000

$ 19,538,000

$ 20,746,000

$ 4,319,000

$ 4,567,000

$ 18,564,000

$ 49,170,000

$ 14,025,000

Agreement with Santen Pharmaceutical Co., Ltd. [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Revenue recognition milestone achieved

0

$ 199,000

$ 228,000

Cumulative aggregate payments received by the Company

3,300,000

Agreement with Santen Pharmaceutical Co., Ltd. [Member] | License Fees [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 2,000,000

Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Maximum [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Future milestone payments

76,000,000

Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Development-Based Milestones [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Future milestone payments

13,000,000

Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Commercialization-Based Milestones [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Future milestone payments

$ 63,000,000

Revenue recognition milestone achieved

$ 0

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Strategic Agreements - Summar_3

Strategic Agreements - Summary of Collaborative Research and Development Revenue Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018	[1]	Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 31, 2017	[1]	Sep. 30, 2017		Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development revenue	$ 3,627		$ 8,036		$ 3,413		$ 3,488		$ 19,538		$ 20,746	[1]	$ 4,319		$ 4,567		$ 18,564	$ 49,170	$ 14,025
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ratable recognition of upfront payment																	0	199	228
Research and development expenses reimbursable by the Company																	102	95	286
Agreement with Santen Pharmaceutical Co., Ltd. [Member] | Collaborative Research and Development Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development revenue																	102	294	514
Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ratable recognition of upfront payment											$ 750						$ 0	833	208
Research and development expenses reimbursable by the Company																		2	347
Agreement with Zogenix, Inc. [Member] | Collaborative Research and Development Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development revenue																		$ 835	$ 555
[1]	The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Strategic Agreements - Agreem_3

Strategic Agreements - Agreement with Sandoz AG - Additional Information (Detail) - USD ($)

1 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2017

May 31, 2017

Dec. 31, 2018

[1]

Sep. 30, 2018

[1]

Jun. 30, 2018

[1]

Mar. 31, 2018

[1]

Dec. 31, 2017

[1]

Sep. 30, 2017

[1]

Jun. 30, 2017

[1]

Mar. 31, 2017

[1]

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

May 31, 2018

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 3,627,000

$ 8,036,000

$ 3,413,000

$ 3,488,000

$ 19,538,000

$ 20,746,000

$ 4,319,000

$ 4,567,000

$ 18,564,000

$ 49,170,000

$ 14,025,000

Agreement with Sandoz AG [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Notice period to terminate agreement, in days

30 days

Notice period to terminate rights, in months

6 months

Cumulative aggregate payments received by the Company

20,000,000

Agreement with Sandoz AG [Member] | License Fees [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 20,000,000

$ 20,000,000

20,000,000

Agreement with Sandoz AG [Member] | Collaborative Research and Development Revenue [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Total revenues

$ 0

$ 20,000,000

$ 0

Maximum [Member] | Agreement with Sandoz AG [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Performance milestone payments based on successful development

30,000,000

Performance milestone payments based on NDA approval

$ 30,000,000

Sales-Based Milestones [Member] | Maximum [Member] | Agreement with Sandoz AG [Member]

Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]

Performance milestone payments based on successful development

$ 230,000,000

$ 230,000,000

[1]

The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Strategic Agreements - Agreem_4

Strategic Agreements - Agreement with Zogenix, Inc. - Additional Information (Detail) - Agreement with Zogenix, Inc. [Member] - USD ($) $ in Thousands	Aug. 31, 2017	Jul. 31, 2011	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable upfront fee		$ 2,250		$ 2,250
Agreement termination month and year	2017-08
Amounts related to the ratable recognition of upfront fees			$ 750	0	$ 833	$ 208
Cumulative aggregate payments received by the Company				$ 20,100

Financial Instruments - Fair Va

Financial Instruments - Fair Value Measurements of Assets (Detail) - Fair Value on Recurring Basis [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 32,876	$ 35,322
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	502	568
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	32,374	34,754
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	502	568
Money market funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	502	568
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	32,224	33,307
Commercial paper [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 32,224	33,307
Corporate Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total		1,297
Corporate Debt [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total		$ 1,297

Financial Instruments - Summary

Financial Instruments - Summary of Money Market Funds and Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 32,876	$ 35,323
Unrealized Loss		(1)
Estimated Fair Value	32,876	35,322
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	502	568
Estimated Fair Value	502	568
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	32,224	33,307
Estimated Fair Value	32,224	33,307
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	30,055	27,788
Estimated Fair Value	30,055	27,788
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,671	7,385
Unrealized Loss		(1)
Estimated Fair Value	2,671	7,384
Long-term restricted investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	150	150
Estimated Fair Value	$ 150	150
Corporate Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,298
Unrealized Loss		(1)
Estimated Fair Value		$ 1,297

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, 2018USD ($)
Investments Debt And Equity Securities [Abstract]
Mature in one year or less, Amortized Cost	$ 32,374
Amortized Cost	32,374
Mature in one year or less, Estimated Fair Value	32,374
Estimated Fair Value	$ 32,374

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail)	Dec. 31, 2018USD ($)
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, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 22,646	$ 22,736
Less accumulated depreciation and amortization	(22,041)	(21,807)
Property and equipment, net	605	929
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,785	12,688
Leasehold improvement [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,828	9,929
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 33	$ 119

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Depreciation expense	$ 254,000	$ 437,000	$ 416,000
Amortization expense	0	$ 0	$ 0
Restoration cost	$ 470,000

Restricted Investments - Additi

Restricted Investments - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
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 - Additional Inform

Commitments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2018ft²	Aug. 31, 2018ft²	Apr. 30, 2018ft²
Commitment And Contingencies [Line Items]
Rent expenses of operating leases	$ 1,900,000	$ 1,900,000	$ 1,900,000
Remaining minimum purchase commitment	500,000
Cost of goods sold	$ 4,263,000	6,633,000	$ 5,290,000
Product Revenue, Net [Member] | Other Purchase Commitments [Member]
Commitment And Contingencies [Line Items]
Cost of goods sold		$ 500,000
Vacaville, CA [Member] | Manufacturing [Member] | Lease Amendment [Member]
Commitment And Contingencies [Line Items]
Square foot facility under lease | ft²						24,634
Cupertino, California [Member] | Office, Laboratory and Manufacturing [Member] | Lease Amendment [Member]
Commitment And Contingencies [Line Items]
Square foot facility under lease | ft²					30,149
Cupertino, California [Member] | Office and Laboratory [Member] | Lease Amendment [Member]
Commitment And Contingencies [Line Items]
Square foot facility under lease | ft²				20,100

Commitments - Summary of Lease

Commitments - Summary of Lease Arrangements of Company Facilities (Detail)	Aug. 31, 2018ft²	Sep. 30, 2018ft²	Apr. 30, 2018ft²	Dec. 31, 2018ft²Option
Cupertino, CA [Member] | Office, Laboratory and Manufacturing [Member] | Lease Amendment [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet	30,149
Expiration				Lease expires 2024 (with an option to renew for an additional five years)
Lease expiration year	2,024
Lease renewal term	5 years
Cupertino, CA [Member] | Office and Laboratory [Member] | Lease Amendment [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet		20,100
Expiration				Lease expires 2024 (with an option to renew for an additional five years)
Lease expiration year		2,024
Lease renewal term		5 years
Vacaville, CA [Member] | Manufacturing [Member] | Lease Amendment [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet			24,634
Expiration				Lease expires 2023 (with an option to renew for an additional five years)
Lease expiration year			2,023
Lease renewal term			5 years
Birmingham,AL [Member] | Office, Laboratory and Manufacturing [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Approximate Square Feet				21,540
Expiration				Lease expires 2021 (with two options to renew the lease term for an additional five years each after the current lease expires)
Lease expiration year				2,021
Lease renewal term				5 years
Number of renewal option for lease | Option				2

Commitments - Schedule of Futur

Commitments - Schedule of Future Operating Lease Minimum Payments (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2,019	$ 2,122
2,020	2,200
2,021	2,126
2,022	1,991
2023 and thereafter	2,245
Total operating leases future minimum payments	$ 10,684

Term Loan - Additional Informat

Term Loan - Additional Information (Detail) - USD ($)	Nov. 01, 2018	Feb. 28, 2018	Jul. 31, 2016	Dec. 31, 2018
Oxford Finance LLC Term Loan [Member]
Debt Instrument [Line Items]
Secured term loan			$ 20,000,000
Term loan repayment description				The Loan Agreement provides for interest only payments for the first 18 months, followed by consecutive monthly payments of principal and interest in arrears starting on March 1, 2018
First principal payment date		Dec. 1, 2018	Mar. 1, 2018
Term loan, maturity date			Aug. 1, 2020
Interest rate on term loan			7.95%	9.83%
Term loan, floating interest rate basis				index rate plus a spread
Facility fee paid at final payment			$ 150,000
Percentage of an additional payment equal to principal amount		10.00%	9.25%
Debt offering/issuance costs			$ 1,900,000
Loan modification fee		$ 100,000
Oxford Finance LLC Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee			1.00%
Oxford Finance LLC Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee			3.00%
Oxford Finance Second Amendment Term Loan [Member]
Debt Instrument [Line Items]
First principal payment date	Jun. 1, 2020	Dec. 1, 2018
Term loan, maturity date	Nov. 1, 2022		Aug. 1, 2020
Loan modification fee	$ 900,000
Oxford Finance Second Amendment Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee	0.75%
Oxford Finance Second Amendment Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of prepayment fee	2.50%

Term Loan - Schedule of Future

Term Loan - Schedule of Future Maturities and Interest Payments under Term Loan (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Future maturities and interest payments under the term loan:
2,019	$ 1,612
2,020	6,824
2,021	8,885
2,022	8,912
Total minimum payments	26,233
Less amount representing interest	(4,750)
Gross balance of term loan	21,483
Less unamortized debt discount	(950)
Carrying value of term loan	20,533
Less term loan, current portion, net		$ (7,281)
Term loan, non-current portion, net	$ 20,533	$ 13,578

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2018	Nov. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from sale of common stock, net of commission	$ 16,780,000	$ 11,989,000	$ 23,745,000
Underwritten public offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from sale of common stock, net of commission			$ 16,100,000
Sale of common stock during period			13.8
Public offering price for common stock			$ 1.25
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered				$ 175,000,000	$ 125,000,000
Cantor Fitzgerald Co [Member] | Controlled Equity Offering Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from sale of common stock, net of commission	$ 16,800,000	$ 12,000,000	$ 7,600,000
Sale of common stock during period	9.6	8.9	5.2
Common stock weighted average price	$ 1.80	$ 1.39	$ 1.50
Cantor Fitzgerald Co [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered					$ 40,000,000
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, 2016	Jun. 30, 2014	Apr. 30, 2013	Jun. 30, 2011	Mar. 31, 2000	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved common stock for issuance						39,936,733
Options exercised, shares						4,267,360
Shares available for future grant						9,257,933
Common stock outstanding						30,317,615	30,301,405
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
Issuance of common stock upon equity financing, net of issuance cost	5,000,000	4,000,000		5,500,000
Reserved common stock for issuance						33,449,989
Plan expiry date						Jun. 30, 2020
Options exercised, shares			70,000
Option plan vesting period			10 years
Options granted with different vesting terms						5 years
Minimum percentage of total combined voting power of stock						10.00%
Minimum exercise price as percentage of fair market value to holder of more than 10% voting power						110.00%
Minimum exercise price as percentage of fair market value to holder of 10% or less voting power						100.00%
Shares available for future grant						9,257,933
Common stock outstanding						30,217,615
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					30,000

Stockholders' Equity - 2000 Dir

Stockholders' Equity - 2000 Directors' Stock Option Plan - Additional Information (Detail) - shares	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock outstanding	30,317,615	30,301,405
2000 Directors' Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock outstanding	100,000

Stockholders' Equity - 2000 Emp

Stockholders' Equity - 2000 Employee Stock Purchase Plan - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Mar. 31, 2015	Apr. 30, 2010	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share available for future grant			9,257,933
Common stock, shares issued			162,060,000	150,837,000
Options granted with exercise prices lower than fair market			$ 0	$ 0	$ 0
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			85.00%
Stock option increase	350,000	250,000
Extended term of stock plan to the date	10 years	10 years
Plan expiry date			Jun. 30, 2025
Options shares reserved for issuance			2,900,000
Share available for future grant			361,185			1,900,000	1,700,000	1,400,000
Common stock, shares issued			2,538,815
Intrinsic value of options exercised			$ 1,600,000	$ 328,000	$ 158,000
Weighted-average grant-date fair value of all options granted with exercise prices			$ 0.94	$ 0.92	$ 0.81

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shares of Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2018	Jan. 31, 2018	Dec. 31, 2017	Jan. 31, 2017	Jan. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding	30,317,615		30,301,405
Stock options available for grant	9,257,933
Shares of common stock reserved for future issuance	39,936,733
2000 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options available for grant	361,185	1,900,000		1,700,000	1,400,000
Shares of common stock reserved for future issuance	361,185

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, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding, Number of Options, beginning balance	30,301,405
Options granted, Number of Options	4,267,360
Options exercised, Number of Options	(1,474,441)
Options forfeited, Number of Options	(672,015)
Options expired, Number of Options	(2,104,694)
Outstanding, Number of Options, ending balance	30,317,615	30,301,405
Exercisable, Number of Options	27,130,089
Vested and expected to vest, Number of Options	30,317,615
Outstanding, Number of Options, Weighted Average Exercise Price Per Share, beginning balance	$ 1.87
Options granted, Weighted Average Exercise Price Per Share	1.31
Options exercised, Weighted Average Exercise Price Per Share	1.11
Options forfeited, Weighted Average Exercise Price Per Share	1.33
Options expired, Weighted Average Exercise Price Per Share	4.86
Outstanding, Number of Options, Weighted Average Exercise Price Per Share, ending balance	1.63	$ 1.87
Exercisable, Number of Options, Weighted Average Exercise Price Per Share	1.67
Vested and expected to vest, Number of Options, Weighted Average Exercise Price Per Share	$ 1.63
Outstanding, Number of Options, Weighted Average Remaining Contractual Term	5 years 7 days	5 years 2 months 5 days
Exercisable, Number of Options, Weighted Average Remaining Contractual Term	4 years 7 months 24 days
Vested and expected to vest, Number of Options, Weighted Average Remaining Contractual Term	5 years 7 days
Outstanding, Number of Options, Aggregate Intrinsic Value		$ 0.4

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	$ 2,998	$ 2,605	$ 2,655
Cost of product revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	94	109	106
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	1,549	1,415	1,433
Selling, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	$ 1,355	$ 1,081	$ 1,116

Stockholders' Equity - Determin

Stockholders' Equity - Determining Fair Value - Additional Information (Detail) - 2000 Employee Stock Purchase Plan [Member] - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
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	119,097	122,033	114,025
Recognition of expenses on shares purchased under employee stock purchase plan	$ 24,000	$ 34,000	$ 45,000
Expected total unrecognized compensation costs related to nonvested stock options	$ 2,500,000
Weighted average term of unrecognized stock-based compensation expense	2 years 1 month 6 days
Cash received from option exercises under stock-based compensation plans	$ 1,600,000	$ 562,000	$ 290,000

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Employees Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate, minimum		1.30%	0.60%	0.30%
Risk-free rate, maximum		2.50%	1.30%	0.60%
Expected term (in years)		6 months	6 months	6 months
Volatility, minimum		60.00%	44.00%	65.00%
Volatility, maximum		146.00%	146.00%	81.00%
Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate, minimum		2.70%	2.00%	1.30%
Risk-free rate, maximum		3.10%	2.50%	2.40%
Volatility, minimum		78.00%	75.00%	76.00%
Volatility, maximum		86.00%	86.00%	83.00%
Forfeiture rate	[1]	0.00%	0.00%	4.20%
Stock Option Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		7 years	6 years 9 months 18 days	6 years 6 months
Stock Option Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		10 years	10 years	10 years
[1]	Effective January 1, 2017, the Company elected to account for forfeitures as they occur.

Stockholders' Equity - Summar_5

Stockholders' Equity - Summary of Stock Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Range of Exercise Price, $0.73 - $0.88 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	$ 0.73
Options Outstanding, Range of Exercise Price, maximum	$ 0.88
Number of Options Outstanding | shares	4,574,794
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	4 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 0.84
Number of Options Exercisable | shares	4,482,934
Options Exercisable, Weighted-Average Exercise Price	$ 0.84
Range of Exercise Price, $0.93 - $1.19 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	0.93
Options Outstanding, Range of Exercise Price, maximum	$ 1.19
Number of Options Outstanding | shares	3,164,866
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.15
Number of Options Exercisable | shares	2,666,690
Options Exercisable, Weighted-Average Exercise Price	$ 1.15
Range of Exercise Price, $1.20 - $1.20 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1.20
Options Outstanding, Range of Exercise Price, maximum	$ 1.20
Number of Options Outstanding | shares	114,293
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	5 years 6 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.20
Number of Options Exercisable | shares	114,293
Options Exercisable, Weighted-Average Exercise Price	$ 1.20
Range of Exercise Price, $1.21 - $1.21 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1.21
Options Outstanding, Range of Exercise Price, maximum	$ 1.21
Number of Options Outstanding | shares	3,151,604
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	4 years 1 month 9 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.21
Number of Options Exercisable | shares	3,140,354
Options Exercisable, Weighted-Average Exercise Price	$ 1.21
Range of Exercise Price, $1.24 - $1.24 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1.24
Options Outstanding, Range of Exercise Price, maximum	$ 1.24
Number of Options Outstanding | shares	3,345,280
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	8 years 10 months 9 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.24
Number of Options Exercisable | shares	2,101,191
Options Exercisable, Weighted-Average Exercise Price	$ 1.24
Range of Exercise Price, $1.26 - $1.26 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1.26
Options Outstanding, Range of Exercise Price, maximum	$ 1.26
Number of Options Outstanding | shares	140,000
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	4 years 1 month 28 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.26
Number of Options Exercisable | shares	140,000
Options Exercisable, Weighted-Average Exercise Price	$ 1.26
Range of Exercise Price, $1.31 - $1.31 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1.31
Options Outstanding, Range of Exercise Price, maximum	$ 1.31
Number of Options Outstanding | shares	3,239,274
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	7 years 7 months 17 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.31
Number of Options Exercisable | shares	2,275,895
Options Exercisable, Weighted-Average Exercise Price	$ 1.31
Range of Exercise Price, $1.33 - $2.04 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1.33
Options Outstanding, Range of Exercise Price, maximum	$ 2.04
Number of Options Outstanding | shares	2,171,924
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 9 months 14 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.48
Number of Options Exercisable | shares	2,113,048
Options Exercisable, Weighted-Average Exercise Price	$ 1.47
Range of Exercise Price, $2.09 - $2.09 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	2.09
Options Outstanding, Range of Exercise Price, maximum	$ 2.09
Number of Options Outstanding | shares	3,691,859
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	3 years 8 months 8 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.09
Number of Options Exercisable | shares	3,684,734
Options Exercisable, Weighted-Average Exercise Price	$ 2.09
Range of Exercise Price, $2.10 - $3.61 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	2.10
Options Outstanding, Range of Exercise Price, maximum	$ 3.61
Number of Options Outstanding | shares	6,723,721
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	1 year 9 months
Options Outstanding, Weighted-Average Exercise Price	$ 2.76
Number of Options Exercisable | shares	6,410,950
Options Exercisable, Weighted-Average Exercise Price	$ 2.79
Range of Exercise Price, $0.73 - $3.61 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	0.73
Options Outstanding, Range of Exercise Price, maximum	$ 3.61
Number of Options Outstanding | shares	30,317,615
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	5 years 7 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.63
Number of Options Exercisable | shares	27,130,089
Options Exercisable, Weighted-Average Exercise Price	$ 1.67

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Deferred tax liability	$ 244,000	$ 244,000
Deferred tax assets	244,000
Deferred income tax provision	$ 0	(153,000)	$ 0
Total income tax provision (benefit) expense		$ (150,000)
Statutory federal income tax rate	21.00%	34.00%	34.00%
Increase (decrease) in valuation allowance of net deferred tax assets	$ 6,300,000	$ (43,100,000)	$ 11,400,000
Unrecognized tax benefits	8,432,000	7,849,000	6,982,000
Interest and penalty expense related to unrecognized tax benefits	0	0	0
Provisional amount related to re-measurement of deferred tax balance due to Tax Cut and Jobs Act		42,500,000
Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards for income tax purposes	347,900,000
Net operating loss carryforwards expiration amount	327,100,000
Net operating loss carryforwards non-expiration amount	$ 20,800,000
Tax carryforwards expire date	2019 through 2037
Research [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Tax carryforwards expire date	2019 through 2038
Research and development tax credits	$ 13,500,000
Interest and other income, net [Member]
Income Tax Contingency [Line Items]
Total income tax provision (benefit) expense	0	(150,000)	$ 0
State [Member]
Income Tax Contingency [Line Items]
Total income tax provision (benefit) expense	0	$ 3,000
Net operating loss carryforwards for income tax purposes	$ 211,800,000
Tax carryforwards expire date	2019 through 2038
State [Member] | Research [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 14,600,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expenses (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. federal taxes benefit at statutory rate	$ (5,318)	$ (1,307)	$ (11,733)
State taxes	0	3	0
Change in valuation allowance	5,143	(41,865)	10,847
Stock-based compensation	999	1,832	2,045
Change in deferred	175	12	(3)
Deferred Tax Remeasurement	0	42,528
Other	$ (999)	(1,353)	$ (1,156)
Total income tax provision (benefit)		$ (150)

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Company's Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carryforwards	$ 87,275,000	$ 82,369,000
Research and other credits	17,524,000	16,303,000
Deferred revenue	277,000	395,000
Stock-based compensation	4,755,000	5,053,000
Other	2,823,000	2,261,000
Total deferred tax assets	112,654,000	106,381,000
Valuation allowance for deferred tax assets	(112,654,000)	(106,381,000)
Deferred tax liabilities—Intangibles	(244,000)	(244,000)
Net deferred tax 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, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 7,849	$ 6,982
Decreased related to prior year tax positions	(7)
Increased related to current year tax positions	590	867
Balance at end of the year	$ 8,432	$ 7,849

Unaudited Selected Quarterly _3

Unaudited Selected Quarterly Financial Data - Selected Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Revenue	$ 3,627	[1]	$ 8,036	[1]	$ 3,413	[1]	$ 3,488	[1]	$ 19,538	[1]	$ 20,746	[1]	$ 4,319	[1]	$ 4,567	[1]	$ 18,564	$ 49,170	$ 14,025
Net income (loss)	$ (7,299)		$ (2,715)		$ (7,011)		$ (8,297)		$ 8,235		$ 6,111		$ (9,927)		$ (8,114)		$ (25,322)	$ (3,695)	$ (34,509)
Basic net income (loss) per share	$ (0.05)		$ (0.02)		$ (0.04)		$ (0.05)		$ 0.06		$ 0.04		$ (0.07)		$ (0.06)		$ (0.16)	$ (0.03)	$ (0.26)
Diluted net income (loss) per share	$ (0.05)		$ (0.02)		$ (0.04)		$ (0.05)		$ 0.05		$ 0.04		$ (0.07)		$ (0.06)		$ (0.16)	$ (0.03)	$ (0.26)
[1]	The figures for the second, third and fourth quarters of 2017 include $0.8 million, $3.8 million and $15.4 million, respectively, related to the recognition of $20.0 million in revenue associated with a nonrefundable upfront payment that the Company received in June 2017 under its license agreement with SANDOZ. In addition, the third quarter of 2017 figure also includes the recognition of a non-refundable payment of $12.5 million received in September 2017 under the Company’s patent purchase agreement with Indivior. The third quarter of 2018 figure includes the recognition of $5.0 million in revenue associated with a nonrefundable milestone payment that the Company received in August 2018 under its agreement with Indivior.

Unaudited Selected Quarterly _4

Unaudited Selected Quarterly Financial Data - Selected Quarterly Financial Data (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 26, 2017	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Agreement with Sandoz AG [Member]
Quarterly Financial Data [Line Items]
Amounts related to the ratable recognition of upfront fees			$ 15,400	$ 3,800	$ 800	$ 0	$ 20,000	$ 0
Patent Purchase Agreement with Indivior [Member]
Quarterly Financial Data [Line Items]
Upfront non-refundable payment received	$ 12,500			$ 12,500
Amount related to the milestone payment earned		$ 5,000				$ 5,000	$ 0	$ 0

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail)	Jan. 27, 2019
Subsequent Event [Member] | Agreement with Sandoz AG [Member]
Subsequent Event [Line Items]
Agreement terminating date	Jan. 27, 2019

Schedule II-Valuation and Qua_2

Schedule II-Valuation and Qualifying Accounts (Detail) - Allowance for doubtful accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the year	$ 155	$ 73	$ 161
Additions (Reductions) to allowances	(52)	165	(70)
Deductions	(1)	(83)	(18)
Balance at end of the year	$ 102	$ 155	$ 73