DURECT (DRRX) 10-K 1 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 18, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
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 Common Stock, Shares Outstanding		122,065,924
Entity Public Float			$ 242,145,190

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 3,583	$ 2,680
Short-term investments	25,457	30,016
Accounts receivable (net of allowances of $161 at December 31, 2015 and $211 at December 31, 2014)	2,222	2,122
Inventories	3,917	3,642
Prepaid expenses and other current assets	3,142	1,034
Total current assets	38,321	39,494
Property and equipment, net	1,566	1,749
Goodwill	6,399	6,399
Long-term investments		1,804
Long-term restricted investments	250	350
Other long-term assets	236	288
Total assets	46,772	50,084
Current liabilities:
Accounts payable	1,286	1,021
Accrued liabilities	4,970	5,051
Contract research liabilities	575	358
Deferred revenue, current portion	616	538
Total current liabilities	7,447	6,968
Deferred revenue, non-current portion	2,269	2,742
Long-term debt, net	19,684	19,824
Other long-term liabilities	$ 2,489	$ 2,035
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: 200,000 shares authorized; 121,839 and 113,733 shares issued and outstanding at December 31, 2015 and 2014, respectively	$ 12	$ 11
Additional paid-in capital	420,453	401,322
Accumulated other comprehensive income (loss)	(14)	87
Accumulated deficit	(405,568)	(382,905)
Stockholders' equity	14,883	18,515
Total liabilities and stockholders' equity	$ 46,772	$ 50,084

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowances for accounts receivable	$ 161	$ 211
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	200,000,000	200,000,000
Common stock, shares issued	121,839,000	113,733,000
Common stock, shares outstanding	121,839,000	113,733,000

Statements of Operations And Co

Statements of Operations And Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Collaborative research and development and other revenue	$ 7,832	$ 8,256	$ 3,590
Product revenue, net	11,292	11,145	11,736
Total revenues	19,124	19,401	15,326
Operating expenses:
Cost of product revenues	3,905	5,686	4,837
Research and development	24,317	22,429	18,945
Selling, general and administrative	11,566	12,284	12,706
Total operating expenses	39,788	40,399	36,488
Loss from operations	(20,664)	(20,998)	(21,162)
Other income (expense):
Interest and other income (expenses)	237	39	(284)
Interest expense	(2,236)	(1,151)	(6)
Net other income (expense)	(1,999)	(1,112)	(290)
Net loss	(22,663)	(22,110)	(21,452)
Net change in unrealized gain (loss) on available-for-sale securities, net of tax	(101)	86	(5)
Total comprehensive loss	$ (22,764)	$ (22,024)	$ (21,457)
Net loss per share
Basic	$ (0.19)	$ (0.20)	$ (0.21)
Diluted	$ (0.19)	$ (0.20)	$ (0.21)
Weighted-average shares used in computing net loss per share
Basic	118,523	111,666	103,078
Diluted	118,523	111,666	103,078

Statement of Stockholders' Equi

Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive income [Member]	Accumulated deficit [Member]
Beginning balance at Dec. 31, 2012	$ 36,331	$ 10	$ 375,658	$ 6	$ (339,343)
Beginning balance, shares at Dec. 31, 2012		101,880,000
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	315		315
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		315,000
Issuance of common stock upon equity financing, net of issuance costs	10,675	$ 1	10,674
Issuance of common stock upon equity financing, net of issuance cost, shares		8,214,000
Stock-based compensation expense from stock options and ESPP shares	4,857		4,857
Net income (loss)	(21,452)				(21,452)
Change in unrealized gain on available-for-sale securities, net of tax	(5)			(5)
Ending balance at Dec. 31, 2013	30,721	$ 11	391,504	1	(360,795)
Ending balance, shares at Dec. 31, 2013		110,409,000
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	399		399
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		416,000
Issuance of common stock upon equity financing, net of issuance costs	$ 4,618		4,618
Issuance of common stock upon equity financing, net of issuance cost, shares	2,907,664	2,908,000
Stock-based compensation expense from stock options and ESPP shares	$ 4,801		4,801
Net income (loss)	(22,110)				(22,110)
Change in unrealized gain on available-for-sale securities, net of tax	86			86
Ending balance at Dec. 31, 2014	18,515	$ 11	401,322	87	(382,905)
Ending balance, shares at Dec. 31, 2014		113,733,000
Issuance of common stock upon exercise of stock options and purchases of ESPP shares	1,175		1,175
Issuance of common stock upon exercise of stock options and purchases of ESPP shares, shares		1,039,000
Issuance of common stock upon equity financing, net of issuance costs	$ 14,290	$ 1	14,289
Issuance of common stock upon equity financing, net of issuance cost, shares	7,066,607	7,067,000
Stock-based compensation expense from stock options and ESPP shares	$ 3,667		3,667
Net income (loss)	(22,663)				(22,663)
Change in unrealized gain on available-for-sale securities, net of tax	(101)			(101)
Ending balance at Dec. 31, 2015	$ 14,883	$ 12	$ 420,453	$ (14)	$ (405,568)
Ending balance, shares at Dec. 31, 2015		121,839,000

Statement of Stockholders' Equ6

Statement of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Stock issuance costs	$ 491	$ 192	$ 825

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net loss	$ (22,663)	$ (22,110)	$ (21,452)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	425	601	558
Stock-based compensation	2,660	3,080	3,426
Inventory write-off	303	1,227	574
Amortization of debt issuance cost	100	38
Realized gain from sale of marketable equity security, net of tax	(117)
Changes in assets and liabilities:
Accounts receivable	(100)	227	(183)
Inventories	(579)	(1,369)	(681)
Prepaid expenses and other assets	(2,056)	854	370
Accounts payable	265	285	(1,049)
Accrued liabilities	1,385	1,200	3,734
Contract research liability	217	29	(154)
Deferred revenue	(395)	1,729	(591)
Total adjustments	2,108	7,901	6,004
Net cash used in operating activities	(20,555)	(14,209)	(15,448)
Cash flows from investing activities
Purchases of property and equipment	(225)	(204)	(69)
Purchases of available-for-sale securities	(34,318)	(31,823)	(20,403)
Proceeds from maturities of available-for-sale securities	40,619	16,294	21,580
Proceeds from sales of short-term investment	178
Net cash provided by (used in) investing activities	6,254	(15,733)	1,108
Cash flows from financing activities
Payments on equipment financing obligations	(21)	(17)	(9)
Net proceeds from issuances of common stock upon exercise of stock options, and purchases of ESPP shares	1,175	399	315
Net proceeds from issuances of common stock in connection with equity financings	14,290	4,618	10,675
Payment of additional issuance cost for long-term debt	(240)
Net proceeds from issuance of long-term debt		19,786
Net cash provided by financing activities	15,204	24,786	10,981
Net increase (decrease) in cash and cash equivalents	903	(5,156)	(3,359)
Cash and cash equivalents at beginning of year	2,680	7,836	11,195
Cash and cash equivalents at end of year	3,583	2,680	7,836
Supplemental disclosure of cash flow information
Cash paid for interest	$ 1,595	$ 691	$ 6

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
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 developing therapies based on its proprietary drug formulations and delivery platform technologies and its expertise in drug development. 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). Certain other expense balances on the statements of operations and comprehensive income (loss) have been reclassified to conform to the current period presentation. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements, the reported amounts of revenue and expenses during the reported period and related disclosures. Actual results could differ materially from those estimates. 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 and 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 within management’s expectations. 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 REMOXY and another product. In 2015, revenue from the ALZET product line and the LACTEL product line accounted for 36% and 22% of total revenue, respectively. In 2014, revenue from the ALZET product line and the LACTEL product line accounted for 37% and 19% of total revenue, respectively. In 2013, revenue from the ALZET product line and the LACTEL product line accounted for 48% and 26% of total revenue, respectively. In 2015, Zogenix and Tolmar accounted for 26% and 11% of the Company’s total revenues. In 2014, Zogenix and Impax accounted for 23% and 11% of the Company’s total revenues. In 2013, Tolmar accounted for 15% of the Company’s total revenues. Total revenue by geographic region for the years 2015, 2014 and 2013 are as follows (in thousands): Year ended December 31, 2015 2014 2013 United States $ 14,289 $ 15,532 $ 11,087 Japan 1,897 898 1,104 Europe 1,817 1,986 2,089 Other 1,121 985 1,046 Total $ 19,124 $ 19,401 $ 15,326 Revenue by geography is determined by the location of the customer. Inventories Inventories are stated at the lower of cost or market, with cost determined on a first-in, first-out basis. Inventories, in part, include certain excipients that are sold to a customer and included in products awaiting regulatory approval. These inventories are capitalized based on management’s judgment of probable sale prior to their expiration date which in turn is primarily based on non-binding forecasts from our customers as well as management’s internal estimates. The valuation of inventory requires management to estimate the value of inventory that may become expired prior to use. The Company may be required to expense previously capitalized inventory costs upon a change in management’s judgment, due to, among other potential factors, a denial or delay of approval of a customer’s product by the necessary regulatory bodies, or new information that suggests that the inventory will not be saleable. In addition, these circumstances may cause the Company to record a liability related to minimum purchase agreements that the Company has in place for raw materials. In 2014, the Company recorded charges to cost of goods sold of approximately $1.6 million, of which approximately $1.1 million related to the write-down of the cost basis of inventory and $500,000 related to the accrual of a liability for the minimum purchase commitment for the excipients. As of December 31, 2015, the remaining carrying value of the excipients in the Company’s inventory was $1.1 million. In addition, the Company has remaining unrecorded future purchase commitments totaling $1.5 million through 2018. 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 and a reserve for future purchase commitments. The Company’s inventories consisted of the following (in thousands): December 31, 2015 2014 Raw materials $ 1,168 $ 1,242 Work in-process 1,412 1,120 Finished goods 1,337 1,280 Total inventories $ 3,917 $ 3,642 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. Acquired Intangible Assets and Goodwill Acquired intangible assets consist of patents, developed technology, trademarks and customer lists related to the Company’s acquisitions accounted for using the purchase method. Amortization of these purchased intangibles is calculated on a straight-line basis over the respective estimated useful lives of the assets ranging from four to seven years. The Company assesses goodwill for impairment at least annually. 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, 2015, 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 Revenue from the sale of products is recognized when there is persuasive evidence that an arrangement exists, the product is shipped and title transfers to customers, provided no continuing obligation on the Company’s part exists, the price is fixed or determinable and the collectability of the amounts owed is reasonably assured. The Company enters into license and collaboration agreements under which it may receive upfront license fees, research funding and contingent milestone payments and royalties. The Company’s deliverables under these arrangements typically consist of granting licenses to intellectual property rights and providing research and development services. The accounting standards contain a presumption that separate contracts entered into at or near the same time with the same entity or related parties were negotiated as a package and should be evaluated as a single agreement. For multiple element arrangements entered into prior to January 1, 2011, the Company determined whether the elements had value on a stand-alone basis and whether there was objective and reliable evidence of fair value. When the delivered element did not have stand-alone value or there was insufficient evidence of fair value for the undelivered element(s), 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 are 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 represents 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. Returns or credits related to the sale of products have not had a material impact on the Company’s revenues or net loss. Research and development revenue related to services performed under the collaborative arrangements with the Company’s third-party collaborators is recognized as the related research and development services are performed. These research payments received under each respective agreement are not refundable and are generally based on reimbursement of qualified expenses, as defined in the agreements. Research and development expenses under the collaborative research and development agreements generally approximate or exceed the revenue recognized under such agreements over the term of the respective agreements. Deferred revenue may result when the Company does not expend the required level of effort during a specific period in comparison to funds received under the respective agreement. For joint control and funding development activities, the Company recognizes revenue from the net reimbursement of the research and development expenses from our collaborators and records the net payment of research and development expenses to our collaborators as additional research and development expense. Milestone payments under collaborative arrangements are triggered either by the results of the Company’s research and development efforts or by specified sales results by a third-party collaborator. Milestones related to the Company’s development-based activities may include initiation of various phases of clinical trials, successful completion of a phase of development or results from a clinical trial, acceptance of a New Drug Application by the FDA or an equivalent filing with an equivalent regulatory agency in another territory, or regulatory approval by the FDA or by an equivalent regulatory agency in another territory. Due to the uncertainty involved in meeting these development-based milestones, the development-based milestones are considered to be substantial (i.e., not just achieved through passage of time) at the inception of the collaboration agreement. In addition, the amounts of the payments assigned thereto are considered to be commensurate with the enhancement of the value of the delivered intellectual property as a result of the Company’s performance. The Company’s involvement is necessary to the achievement of development-based milestones. The Company would account for development-based milestones as revenue upon achievement of the substantive milestone events. Milestones related to sales-based activities may be triggered upon events such as the first commercial sale of a product or when sales first achieve a defined level. Under the Company’s collaborative agreements, the Company’s third-party collaborators will take the lead in commercialization activities and the Company is typically not involved in the achievement of sales-based milestones. These sales-based milestones would be achieved after the completion of the Company’s development activities. The Company would account for the sales-based milestones in the same manner as royalties, with revenue recognized upon achievement of the milestone. In addition, upon the achievement of either development-based or sales-based milestone events, the Company has no future performance obligations related to any milestone payments. Revenue on cost-plus-fee contracts, such as under contracts to perform research and development for others, is recognized as the related services are rendered as determined by the extent of reimbursable costs incurred plus estimated fees thereon. 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, net reimbursements of research and development expenses incurred by the Company’s partners are recorded as collaborative research and development revenue. Net payments of research and development expenses to the Company’s partners are recorded as an addition to research and development expenses in the period incurred. Comprehensive Income (Loss) Accumulated other comprehensive income (loss) as of December 31, 2015, 2014 and 2013 is entirely comprised of unrealized gains or losses on available-for-sale securities. 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 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 and warrants to purchase common stock) outstanding during the period, if dilutive, using the treasury stock method for options and warrants. 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, 2015 2014 2013 Numerators: Net loss $ (22,663 ) $ (22,110 ) $ (21,452 ) Denominators: Weighted average shares used to compute basic net loss per share 118,523 111,666 103,078 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute basic net loss per share 118,523 111,666 103,078 Net loss per share: Basic $ (0.19 ) $ (0.20 ) $ (0.21 ) Diluted $ (0.19 ) $ (0.20 ) $ (0.21 ) The computation of diluted net loss per share for the years ended December 31, 2015, 2014 and 2013 excludes the impact of options to purchase 16.5 million, 20.0 million and 19.6 million shares of common stock outstanding, respectively, at December 31, 2015, 2014 and 2013, 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 May 2014, the Financial Accounting Standards Board (FASB) issued guidance codified in ASC 606, Revenue Recognition—Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The guidance provides companies with two implementation methods. Companies can choose to apply the standard retrospectively to each prior reporting period presented (full retrospective application) or retrospectively with the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings of the annual reporting period that includes the date of initial application (modified retrospective application). The standard was to have been effective for public entities for annual and interim periods beginning after December 15, 2016. In July 2015, the FASB voted to delay the effective date for this guidance. This guidance is effective for the Company in the first quarter of 2018. Early adoption up to the first quarter of 2017 is permitted. The Company is currently evaluating the impact of the provisions of ASC 606. In August 2014, the FASB issued Accounting Standards Update 2014-15, Presentation of Financial Statements – Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (ASU 2014-15). This update is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 requires management to assess an entity’s ability to continue as a going concern by incorporating and expanding upon certain principles that are currently in U.S. auditing standards. Specifically, the amendments: (1) provide a definition of the term substantial doubt; (2) require an evaluation every reporting period including interim periods; (3) provide principles for considering the mitigating effect of management’s plans; (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans; (5) require an express statement and other disclosures when substantial doubt is not alleviated; and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 will be effective for annual periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016, with early adoption permitted. ASU 2014-15 will be effective for the Company beginning with its annual report for fiscal 2016 and interim periods thereafter. The Company is currently evaluating the impact that ASU 2014-15 will have on its financial statements. In November 2015, the FASB issued Accounting Standards Update 2015-17(ASU 2015-17), Balance Sheet Classification of Deferred Taxes to simplify the presentation of deferred income taxes. The amendments in this update require that deferred tax liabilities and assets be classified as noncurrent on the balance sheet instead of separating deferred taxes into current and noncurrent amounts. The new guidance will be effective for public business entities in fiscal years beginning after December 15, 2016, including interim periods within those years (i.e., in the first quarter of 2017 for calendar year-end companies). Early adoption is permitted for all entities as of the beginning of an interim or annual reporting period. The guidance may be applied either prospectively, for all deferred tax assets and liabilities, or retrospectively (i.e., by reclassifying the comparative balance sheet). The Company has elected to early adopt ASU 2015-17, on a prospective basis, for the year ended December 31, 2015. Prior periods were not retrospectively adjusted. There is no impact to the balance sheet amounts as a result of early adoption.

Strategic Agreements

Strategic Agreements	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 2013 Collaborator Zogenix, Inc. (Zogenix) (1) $ 4,898 $ 4,431 $ 918 Pain Therapeutics, Inc. (Pain Therapeutics) 1,385 1,359 750 Santen Pharmaceutical Co. Ltd. (Santen) (2) 824 16 — Impax Laboratories, Inc. (Impax) (3) — 2,106 — Pfizer Inc. (Pfizer) — 118 42 Others 725 226 1,880 Total collaborative research and development and other revenue $ 7,832 $ 8,256 $ 3,590 (1) Amounts related to ratable recognition of upfront fees were $255,000 in 2015 and 2014, and $241,000 in 2013. (2) Amounts related to ratable recognition of upfront fees were $274,000 in 2015, $15,000 in 2014, and zero in 2013, respectively; the Company and Santen signed a license agreement effective December 11, 2014. (3) Amounts related to recognition of upfront fees were zero in 2015, $2.0 million in 2014 and zero in 2013, respectively; the Company and Impax signed a license agreement effective January 3, 2014. As of February 18, 2016, the Company had potential milestones of up to $245.5 million that the Company may receive in the future under its collaborative arrangements, of which $77.5 million are development-based milestones and $168.0 million are sales-based milestones. Within the category of development-based milestones, $5.0 million are related to early stage clinical testing (defined as Phase 1 or 2 activities), $12.5 million are related to late stage clinical testing (defined as Phase 3 activities), $20.5 million are related to regulatory filings, and $39.5 million are related to regulatory approvals. No payments were received between December 31, 2015 and February 18, 2016. 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 and other oral sustained release, abuse deterrent opioid products incorporating four specified opioid drugs, using the ORADUR technology. Total collaborative research and development revenue recognized under the agreements with Pain Therapeutics was $1.4 million in 2015, $1.4 million in 2014, and $750,000 in 2013. In May 2015, Pain Therapeutics sent a letter to the Company that provided the Company with formal written notice that Pain Therapeutics was deleting, effective as of January 12, 2015, the opioid drug hydrocodone (and only hydrocodone) as a licensed product under the agreement. The letter did not alter the terms of the agreement regarding the remaining three licensed products (REMOXY, hydromorphone or oxymorphone) or otherwise amend the agreement. Under the agreement with Pain Therapeutics, subject to and upon the achievement of predetermined development and regulatory milestones for the three drug candidates, the Company is entitled to receive milestone payments of up to $7.2 million in the aggregate. The cumulative aggregate payments received by the Company from Pain Therapeutics as of December 31, 2015 were $38.5 million under this agreement. 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 $7.2 million in performance milestone payments based on the successful development and approval of the three ORADUR-based opioids. Of these potential milestones, all $7.2 million are development-based milestones. There are no sales-based milestones under the agreement. As of December 31, 2015, the Company had received $1.7 million in cumulative milestone payments. In March 2009, King Pharmaceuticals (King) assumed the responsibility for further development of REMOXY from Pain Therapeutics. As a result of this change, the Company continued to perform REMOXY-related activities in accordance with the terms and conditions set forth in the license agreement between the Company and Pain Therapeutics. King was substituted in lieu of Pain Therapeutics with respect to interactions with the Company in its performance of those activities including the obligation to pay the Company with respect to all REMOXY-related costs incurred by the Company. In February 2011, Pfizer acquired King and thereby assumed the rights and obligations of King with respect to REMOXY; accordingly, amounts attributed to King are shown as Pfizer figures. In October 2014, Pfizer notified Pain Therapeutics that Pfizer had decided to discontinue development of REMOXY, and that Pfizer would return all rights, including responsibility for regulatory activities, to Pain Therapeutics and that Pfizer would continue ongoing activities under the agreement until the scheduled termination date in April 2015. In July 2015, Pain Therapeutics stated that it had substantially completed the transition of REMOXY from Pfizer, and that Pain Therapeutics expected to resubmit the NDA in the first quarter of 2016. Total collaborative research and development revenue recognized for REMOXY-related work performed by the Company for Pfizer was zero, $118,000 and $42,000 for the years ended December 31, 2015, 2014 and 2013, respectively. Total collaborative research and development revenue recognized for REMOXY-related work performed by the Company for Pain Therapeutics was $740,000, zero and zero for the years ended December 31, 2015, 2014 and 2013, respectively. Prior to March 2009 and after November 2014, the Company recognized collaborative research and development revenue for REMOXY-related work under the agreement with Pain Therapeutics. The cumulative aggregate payments received by the Company from Pfizer as of December 31, 2015 were $7.1 million under this agreement. Long Term Supply Agreement with King (now Pfizer) In August 2009, the Company signed an exclusive long term excipient supply agreement with respect to REMOXY with King. In February 2011, Pfizer acquired King and thereby assumed the rights and obligations of King with respect to this long term supply agreement. This agreement stipulated the terms and conditions under which the Company would supply to King, based on the Company’s manufacturing cost plus a specified percentage mark-up, two key excipients used in the manufacture of REMOXY. The term of the agreement commenced in August 2009 and continued in effect until April 2015, when the related development and license agreement between Pain Therapeutics and King terminated. In 2015, 2014 and 2013, the Company recognized $96,000, $33,000 and $273,000 of product revenue, respectively, related to key excipients for REMOXY and the associated cost of goods sold was $51,000, zero and $165,000, respectively. 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 will be 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 ® Zogenix paid a non-refundable upfront fee to the Company of $2.25 million in July 2011. The Company’s research and development services are considered integral to utilizing the licensed intellectual property and, accordingly, the deliverables are accounted for as a single unit of accounting. The $2.25 million upfront fee is being recognized as collaborative research and development revenue ratably over the term of the Company’s continuing research and development involvement with Zogenix with respect to this product candidate. Zogenix is obligated to pay the Company up to $103 million in total future milestone payments with respect to the product subject to and upon the achievement of various developments, regulatory and sales milestones. Of these potential milestones, $28 million are development-based milestones (none of which has been achieved as of December 31, 2015), and $75 million are sales-based milestones (none of which has been achieved as of December 31, 2015). Zogenix is also required to pay a mid single-digit to low double-digit percentage patent royalty on annual net sales of the product determined on a jurisdiction-by-jurisdiction basis. The patent royalty term is equal to the later of the expiration of all DURECT technology patents or joint patent rights in a particular jurisdiction, the expiration of marketing exclusivity rights in such jurisdiction, or 15 years from first commercial sale in such jurisdiction. After the patent royalty term, Zogenix will continue to pay royalties on annual net sales of the product at a reduced rate for so long as Zogenix continues to sell the product in the jurisdiction. Zogenix is also required to pay to the Company a tiered percentage of fees received in connection with any sublicense of the licensed rights. 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 retains the right to supply Zogenix’s Phase III clinical trial and commercial product requirements on the terms set forth in the Zogenix Agreement. Zogenix may terminate the Zogenix Agreement without cause at any time upon prior written notice, and either party may terminate the Zogenix Agreement upon certain circumstances including written notice of a material uncured breach. 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, 2015 were $19.3 million under these agreements. Year Ended December 31, 2015 2014 2013 Ratable recognition of upfront payment $ 255 $ 255 $ 241 Research and development expenses reimbursable by Zogenix 4,643 4,176 677 Total collaborative research and development revenue $ 4,898 $ 4,431 $ 918 Agreement with Impax Laboratories, Inc. On January 3, 2014, the Company and Impax Laboratories, Inc. (Impax) entered into a definitive agreement (the Impax Agreement). Pursuant to the Impax Agreement, the Company granted Impax an exclusive worldwide license to the Company’s proprietary TRANSDUR transdermal delivery technology and other intellectual property to develop and commercialize ELADUR, the Company’s investigational transdermal bupivacaine patch for the treatment of pain associated with post-herpetic neuralgia (PHN), in addition to selling certain assets and rights in and related to the product. Impax will control and fund the development and commercialization programs, and the parties established a joint management committee to oversee, review and coordinate the development and commercialization activities of the parties under the Impax Agreement. Impax will reimburse the Company for certain future research and development it may be requested to conduct on the product. In connection with the Impax Agreement, Impax paid a non-refundable upfront fee to the Company of $2.0 million in January 2014. The Company’s technology transfer activities were considered integral to utilizing the licensed intellectual property and, accordingly, the deliverables were accounted for as a single unit of accounting. The $2.0 million upfront fee was recognized as collaborative research and development revenue in the first quarter of 2014 when the license to the intellectual property right was delivered and the technology transfer with respect to this product candidate was completed. Impax agreed to make contingent cash payments to the Company of up to $61.0 million payable based upon the achievement of predefined milestones, of which $31.0 million are development-based milestones and $30.0 million are sales-based milestones (none of which has been achieved as of December 31, 2015). Since the milestones are expected to be achieved at a point in time when there are no performance obligations or remaining deliverables of the Company, the milestones are expected to be recognized in full upon achievement. Upon the first commercialization of ELADUR by Impax, the Company would also receive a tiered mid single-digit to low double-digit royalty on annual net product sales determined on a country-by-country basis. Impax is also required to pay to the Company a percentage of fees received in connection with any sublicense of the licensed rights. Impax may terminate the Impax Agreement without cause at any time upon prior written notice, and either party may terminate the Impax Agreement upon certain circumstances including written notice of a material uncured breach. The following table provides a summary of collaborative research and development revenue recognized under the Impax Agreement (in thousands). The cumulative aggregate payments received by the Company as of December 31, 2015 were $2.1 million under the agreement. Year Ended December 31, 2015 2014 2013 Ratable recognition of upfront payment $ — $ 2,000 $ — Research and development expenses reimbursable by Impax — 106 — Total collaborative research and development revenue $ — $ 2,106 $ — 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, 2015). 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, 2015, the cumulative aggregate payments received by the Company under this agreement were $2.4 million. The following table provides a summary of collaborative research and development revenue recognized under the Santen Agreement (in thousands). Year Ended December 31, 2015 2014 2013 Ratable recognition of upfront payment $ 274 $ 15 $ — Research and development expenses reimbursable by Santen 550 1 — Total collaborative research and development revenue $ 824 $ 16 $ —

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	3. Intangible Assets and Goodwill Intangible assets recorded in connection with the Company’s acquisitions consist of developed technology, patents and certain other intangible assets. The intangible assets were being amortized on a straight-line basis over estimated useful lives ranging from four to seven years. The net amount of intangible assets at December 31, 2015 and 2014 was zero. Goodwill totaled $6.4 million at December 31, 2015. The Company evaluates goodwill for impairment at least annually. In 2015, 2014 and 2013 goodwill was evaluated and no indicators of impairment were noted. Should goodwill become impaired, the Company may be required to record an impairment charge. To date, the Company has not recorded any impairment charge to goodwill.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Financial Instruments	4. 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, 2015 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 81 $ — $ — $ 81 Certificates of deposit — 250 — 250 Commercial paper — 898 — 898 Corporate debt — 5,211 — 5,211 U.S. Government agencies — 19,548 — 19,548 Total $ 81 $ 25,907 $ — $ 25,988 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, 2014 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 1,558 $ — $ — $ 1,558 Certificates of deposit — 350 — 350 Marketable equity security 155 — — 155 Commercial paper — 1,250 — 1,250 Corporate debt — 7,740 — 7,740 U.S. Government agencies — 22,675 — 22,675 Total $ 1,713 $ 32,015 $ — $ 33,728 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, 2015 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, 2015 and 2014 (in thousands): December 31, 2015 Amortized Unrealized Unrealized Estimated Money market funds $ 81 $ — $ — $ 81 Certificates of deposit 250 — — 250 Commercial paper 898 — — 898 Corporate debt 5,215 1 (5 ) 5,211 U.S. Government agencies 19,558 1 (11 ) 19,548 $ 26,002 $ 2 $ (16 ) $ 25,988 Reported as: Cash and cash equivalents $ 281 $ — $ — $ 281 Short-term investments 25,471 2 (16 ) 25,457 Long-term restricted investments 250 — — 250 $ 26,002 $ 2 $ (16 ) $ 25,988 December 31, 2014 Amortized Unrealized Unrealized Estimated Money market funds $ 1,558 $ — $ — $ 1,558 Certificates of deposit 350 — — 350 Marketable equity security — 155 — 155 Commercial paper 1,250 — — 1,250 Corporate debt 7,744 — (4 ) 7,740 U.S. Government agencies 22,678 2 (5 ) 22,675 $ 33,580 $ 157 $ (9 ) $ 33,728 Reported as: Cash and cash equivalents $ 1,558 $ — $ — $ 1,558 Short-term investments 29,867 157 (8 ) 30,016 Long-term investments 1,805 — (1 ) 1,804 Long-term restricted investments 350 — — 350 $ 33,580 $ 157 $ (9 ) $ 33,728 The following is a summary of the cost and estimated fair value of available-for-sale securities at December 31, 2015, by contractual maturity (in thousands): December 31, 2015 Amortized Estimated Mature in one year or less $ 25,921 $ 25,907 Mature after one year through five years — — $ 25,921 $ 25,907 There were no securities that have had an unrealized loss for more than 12 months as of December 31, 2015. As of December 31, 2015, 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, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment consist of the following (in thousands): December 31, 2015 2014 Equipment $ 12,372 $ 12,161 Leasehold improvement 9,987 9,968 Construction-in-progress 178 227 22,537 22,356 Less accumulated depreciation and amortization (20,971 ) (20,607 ) Property and equipment, net $ 1,566 $ 1,749 Depreciation expense was $425,000, $582,000 and $541,000 in 2015, 2014 and 2013, respectively. Amortization expense was $1,000, $17,000 and $9,000 in 2015, 2014 and 2013 for assets held under capital leases, respectively. As of December 31, 2015, the Company has recorded $669,500 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, 2015
Text Block [Abstract]
Restricted Investments	6. Restricted Investments As of December 31, 2015 and 2014, the Company had $250,000 and $350,000, respectively, recorded as restricted investments, which primarily served as collateral for letters of credit securing its leased facilities in Alabama and California.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Commitments	7. Commitments Operating Leases The Company has lease arrangements for its facilities in California and Alabama. 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, $1.8 million, and $1.5 million, for the years ended December 31, 2015, 2014 and 2013, respectively. Future minimum payments under these noncancelable leases are as follows (in thousands): Year ending December 31, Operating 2016 $ 1,970 2017 2,000 2018 1,948 2019 539 Thereafter 518 $ 6,975 Other Purchase Commitments In 2005, the Company entered into a supply agreement with a vendor. The remaining minimum purchase commitments under this agreement are $500,000 per year through 2018. The Company accrued $500,000 as a loss on a purchase obligation and recorded this amount as a charge in cost of goods of sold in the statement of operations and comprehensive income (loss) for the year ended December 31, 2014.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Long-Term Debt	8. Long-Term Debt On June 26, 2014, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Oxford Finance LLC, pursuant to which Oxford provided a $20 million secured single-draw term loan to the Company with a maturity date of July 1, 2018. The term loan was fully drawn at close and the proceeds are to be used for working capital and general business requirements. The term loan repayment schedule provides for interest only payments for the first 18 months, followed by consecutive equal monthly payments of principal and interest in arrears starting on February 1, 2016 and continuing through the maturity date. The Loan Agreement provides for a 7.95% interest rate on the term loan, a $150,000 facility fee that was paid at closing and an additional payment equal to 8% 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 and circumstances of prepayment. In connection with the term loan, the Company received proceeds of $19.8 million, net of debt offering/issuance costs. The debt offering/issuance costs have been recorded as debt discount on the Company’s balance sheet which together with the final $1.6 million payment and fixed interest rate payments will be amortized to interest expense throughout 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, our 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 July 2015, the Company and Oxford Finance entered into the First Amendment of the Loan Agreement and modified the terms to the Loan Agreement to change the maturity date from July 1, 2018 to July 1, 2019 and to change the first principal payment date from February 1, 2016 to February 1, 2017. The interest rate remains unchanged, the Company paid a loan modification fee of $240,000 and the additional payment originally equal to 8% of the principal amount of the term loan, which is due when the term loan becomes due or upon the prepayment of the facility, was increased to 10%. As of December 31, 2015, the Company was in compliance with all material covenants under the Loan Agreement and there had been no material adverse change. The fair value of the term loan approximates the carrying value. Future maturities and interest payments under the term loan as of December 31, 2015, are as follows (in thousands): 2016 $ 1,590 2017 8,848 2018 8,848 2019 6,423 Total minimum payments 25,709 Less amount representing interest (5,709 ) Gross balance of long-term debt 20,000 Less unamortized debt discount (316 ) Carrying value of long-term debt 19,684 Less current portion of long-term debt — Long-term debt, less current portion and unamortized debt discount $ 19,684

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity Common Stock In December 2013, the Company filed a shelf registration statement on Form S-3 with the SEC, which upon being declared effective in January 2014, allowed for the offer of up to $100.9 million of securities from time to time in one or more public offerings of common stock. In addition, the Company entered into a Controlled Equity Offering sales agreement with Cantor Fitzgerald & Co., (Cantor Fitzgerald), under which it may sell, subject to certain limitations, up to $25 million of common stock through Cantor Fitzgerald, acting as agent. In November 2015, we filed a new 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 us to offer up to $125.0 million of securities from time to time in one or more public offerings of our common stock. In addition, we entered into a Controlled Equity Offering sales agreement with Cantor Fitzgerald & Co., (Cantor Fitzgerald), under which we may sell, subject to certain limitations, up to $40 million of common stock through Cantor Fitzgerald, acting as agent. During 2014, we raised net proceeds (net of commissions) of approximately $4.7 million from the sale of 2,907,664 shares of common stock in the open market through the December 2013 agreement with Cantor Fitzgerald at a weighted average price of $1.65 per share. In 2015, we raised net proceeds (net of commissions) of approximately $14.3 million from the sale of 7,066.607 shares of our common stock in the open market through the agreements with Cantor Fitzgerald at a weighted average price of $2.09 per share. 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. In April 2010, the Board of Directors approved certain amendments to the 2000 Stock Plan. At the Company’s annual stockholders meeting in June 2010, the stockholders approved the 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. In March 2011, the Board of Directors approved an amendment to the 2000 Stock Plan. At the Company’s annual stockholders meeting in June 2011, the stockholders approved the amendment 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. A total of 29,294,260 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, 2015, 2,405,807 shares of common stock were available for future grant and options to purchase 26,888,453 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. A total of 300,000 shares of common stock had been reserved initially for issuance under this plan. The directors’ plan provides that each person who becomes a non-employee director of the Company after the effective date of the Company’s initial public offering will be granted a non-statutory stock option to purchase 20,000 shares of common stock on the date on which the optionee first becomes a non-employee director of the Company. This plan also provides that each option granted to a new director shall vest at the rate of 33 1 /3% per year and each annual option of 5,000 shares shall vest in full at the end of one year. At the Company’s annual stockholders meeting in June 2002, the stockholders approved an amendment of the 2000 Directors’ Stock Option 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 20,000 to 30,000 shares of common stock; (ii) increase the number of stock options granted to each non-employee director on the date of each annual meeting of the stockholders after which the director remains on the Board from 5,000 to 12,000 shares of common stock; and (iii) reserve 200,000 additional shares of common stock for issuance under the 2000 Directors’ Stock Option Plan so that the total number of shares reserved for issuance is 500,000. In April 2005, the Board of Directors approved certain amendments to the 2000 Directors’ Stock Option Plan. At the Company’s annual stockholders meeting in June 2005, the stockholders approved the amendments of the 2000 Directors’ Stock Option Plan to: (i) increase the number of shares of common stock issuable under the Director’s Plan by an additional 425,000 shares, to an aggregate of 925,000 shares; (ii) increase the number of option shares issued to nonemployee directors annually in connection with their continued service on the Board from 12,000 shares to 20,000 shares; and (iii) modify the vesting of such annual option grants so that such shares vest completely on the day before the first anniversary of the date of grant. The plan expired in September 2010. Awards to our non-employee directors have been granted under the 2000 Stock Plan following that date. As of December 31, 2015, no shares of common stock were available for future grant and options to purchase 410,000 shares of common stock were outstanding under the 2000 Director’s Stock Option Plan. 2000 Employee Stock Purchase Plan In August 2000, the Company adopted the 2000 Employee Stock Purchase Plan. This purchase plan is implemented by a series of overlapping offering periods of approximately 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 2,550,000 shares of common stock have been reserved for issuance under this plan. As of December 31, 2015, 366,340 shares of common stock were available for future grant and 2,183,660 shares of common stock have been issued under the 2000 Employee Stock Purchase Plan. As of December 31, 2015, shares of common stock reserved for future issuance consisted of the following: December 31, Stock options outstanding 27,298,453 Stock options available for grant 2,405,807 Employee Stock Purchase Plan 366,340 30,070,600 A summary of stock option activity under all stock-based compensation plans is as follows: Number of Weighted Weighted Aggregate Outstanding at December 31, 2012 20,902,156 $ 3.07 5.41 $ — Options granted 4,592,849 $ 1.21 Options exercised (187,014 ) $ 1.01 Options forfeited (94,055 ) $ 1.38 Options expired (1,517,352 ) $ 3.17 Outstanding at December 31, 2013 23,696,584 $ 2.73 5.45 $ 5.2 Options granted 3,747,428 $ 1.94 Options exercised (300,602 ) $ 0.99 Options forfeited (144,611 ) $ 1.50 Options expired (2,758,960 ) $ 2.95 Outstanding at December 31, 2014 24,239,839 $ 2.61 5.72 $ — Options granted 4,299,290 $ 1.09 Options exercised (925,636 ) $ 1.13 Options forfeited (15,990 ) $ 1.34 Options expired (299,050 ) $ 3.58 Outstanding at December 31, 2015 27,298,453 $ 2.41 5.39 $ 13.5 Exercisable at December 31, 2015 23,222,277 $ 2.59 4.86 $ 10.1 Vested and expected to vest at December 31, 2015 27,028,688 $ 2.42 5.36 $ 13.2 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 2015 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 options on December 31, 2015. This amount changes based on the fair market value of the Company’s common stock. The total intrinsic value of options exercised was $985,000, $178,000, and $77,000 for the years ended December 31, 2015, 2014 and 2013, respectively. In January 2015, January 2014 and February 2013, the Company granted its employees stock options to purchase $1.5 million, 966,000, and 1.7 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 $0.65 in 2015, $1.53 in 2014 and $0.85 in 2013 determined by the Black-Scholes option valuation method. There were no options granted with exercise prices lower than fair market value in 2015, 2014 and 2013. Expenses for non-employee stock options are recorded over the vesting period of the options, with the value determined by the Black-Scholes option valuation method and remeasured over the vesting term. As of December 31, 2015, 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, 2015 2014 2013 Cost of product revenues $ 108 $ 149 $ 170 Research and development 1,400 1,697 1,999 Selling, general and administrative 1,152 1,234 1,257 $ 2,660 $ 3,080 $ 3,426 Because the Company had a net operating loss carryforward as of December 31, 2015, 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 2015, 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. Expected Term. Expected Volatility. Risk-Free Rate. Dividends. The Company used the following assumptions to estimate the fair value of options granted (including fully vested options issued in January 2015 and 2014, and February 2013) and shares purchased under its stock plans and employee stock purchase plan for the years ended December 31, 2015, 2014 and 2013: Year ended December 31, 2015 2014 2013 Stock Options Risk-free rate 1.5-2.4 % 1.9-2.8 % 0.9-2.9 % Expected dividend yield — — — Expected term (in years) 6.5-10.0 6.5-10.0 5.3-10.0 Volatility 78-85 % 76-85 % 77-86 % Forfeiture rate 6.0 % 7.2 % 8.4 % Year ended December 31, 2015 2014 2013 Employee Stock Purchase Plan Risk-free rate 0.1-0.3 % 0.1 % 0.1-0.2 % Expected dividend yield — — — Expected term (in years) 0.5 0.5 0.5 Volatility 68-95 % 60-81 % 64-81 % There were 113,625, 115,412 and 128,433 shares purchased under the Company’s employee stock purchase plan during the years ended December 31, 2015, 2014 and 2013, respectively. Included in the statement of operations and comprehensive loss for the year ended December 31, 2015, 2014 and 2013 was $62,000, $43,000 and $56,000, 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, 2015, $3.5 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 2018. 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, 2015: Options Outstanding Options Exercisable Range of Number of Weighted- Weighted- Number of Weighted- $0.73 – 0.87 2,494,482 6.18 $ 0.78 2,346,554 $ 0.78 $0.88 – 0.88 3,235,932 9.02 $ 0.88 1,631,647 $ 0.88 $1.00 – 1.20 388,855 7.63 $ 1.08 310,292 $ 1.10 $1.21 – 1.21 3,537,417 7.09 $ 1.21 3,015,494 $ 1.21 $1.24 – 1.93 1,436,463 8.16 $ 1.46 1,033,358 $ 1.46 $2.09 – 2.09 3,956,166 6.73 $ 2.09 2,949,018 $ 2.09 $2.13 – 2.77 2,739,429 4.32 $ 2.22 2,636,205 $ 2.21 $2.80 – 3.26 4,166,269 4.38 $ 3.16 3,956,269 $ 3.18 $3.29 – 5.27 3,695,694 0.81 $ 4.59 3,695,694 $ 4.59 $5.38 – 6.32 1,647,746 1.92 $ 5.91 1,647,746 $ 5.91 $0.73 – 6.32 27,298,453 5.39 $ 2.41 23,222,277 $ 2.59 The Company received $1.0 million, $299,000 and $188,000 in cash from option exercises under all stock-based compensation plans for the years ended December 31, 2015, 2014 and 2013, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	10. 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 34% to net income tax benefit included in the statements of operations and comprehensive loss for the years ended December 31, 2015, 2014 and 2013 is as follows (in thousands): Year Ended December 31, 2015 2014 2013 U.S. federal taxes provision (benefit) at statutory rate $ (7,681 ) $ (7,502 ) $ (7,184 ) State taxes — — — Change in valuation allowance 7,725 6,854 9,517 Stock-based compensation 530 1,139 375 Change in deferreds 56 (2 ) (1,718 ) Other (577 ) (465 ) (670 ) Total income tax provision $ 53 $ 24 $ 320 In 2015, 2014 and 2013, total income tax provision expense was $53,000, $24,000 and $320,000, respectively. The Company has presented the $53,000, $24,000 and $320,000 of deferred income tax provision in interest and other income (expenses) in its statements of operation and comprehensive income (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, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 111,696 $ 105,609 Research and other credits 12,001 10,995 Capitalized research and development expenses 132 456 Deferred revenue 1,045 516 Stock-based compensation 9,605 9,402 Other 3,645 3,967 Total deferred tax assets 138,124 130,945 Valuation allowance for deferred tax assets (138,124 ) (130,945 ) Deferred tax liabilities—Intangibles (397 ) (405 ) Net deferred tax assets and liabilities $ (397 ) $ (405 ) Realization of deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $7.2, $8.9 million, and $11.7 million during 2015, 2014 and 2013, respectively. As of December 31, 2015, the Company had net operating loss carryforwards for federal income tax purposes of approximately $295.6 million, which expire in the years 2019 through 2035, and federal research and development tax credits of approximately $9.9 million which expire at various dates beginning in 2018 through 2035, if not utilized. As of December 31, 2015, the Company had net operating loss carryforwards for state income tax purposes of approximately $211.3 million, which expire in the years 2015 through 2035, if not utilized, and state research and development tax credits of approximately $10.8 million, which do not expire. Utilization of the net operating losses may be subject to a substantial annual limitation due to federal and state ownership change limitations. The annual limitation may result in the expiration of net operating losses before utilization. At December 31, 2015 and December 31, 2014, the Company had unrecognized tax benefits of approximately $7.0 and $5.7 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, 2015 2014 Balance at beginning of the year $ 5,702 $ 5,252 Increases (decrease) related to prior year tax positions 737 — Increases (decrease) related to current year tax positions 526 450 Settlements — — Reductions due to lapse of applicable statute of limitations — — Balance at end of the year $ 6,965 $ 5,702 Interest and penalty costs related to unrecognized tax benefits, if any, are classified as a component of interest income and other income (expense), net in the accompanying Statements of Operations and Comprehensive Loss. The Company did not recognize any interest and penalty expense related to unrecognized tax benefits for the years ended December 31, 2015, 2014 and 2013. 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 2015 due to unutilized net operating losses and research credits.

Unaudited Selected Quarterly Fi

Unaudited Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Unaudited Selected Quarterly Financial Data	11. Unaudited Selected Quarterly Financial Data (in thousands, except per share amounts) First Quarter Second Quarter Third Quarter Fourth Quarter 2015 2014 2015 2014 2015 2014 2015 2014 Revenue $ 4,773 $ 6,293 $ 4,441 $ 4,581 $ 4,743 $ 4,258 $ 5,167 $ 4,269 Net loss $ (4,853 ) $ (3,600 ) $ (5,478 ) $ (5,478 ) $ (6,487 ) $ (7,092 ) $ (5,845 ) $ (5,940 ) Basic net loss per share $ (0.04 ) $ (0.03 ) $ (0.05 ) $ (0.05 ) $ (0.05 ) $ (0.06 ) $ (0.05 ) $ (0.05 ) Diluted net loss per share $ (0.04 ) $ (0.03 ) $ (0.05 ) $ (0.05 ) $ (0.05 ) $ (0.06 ) $ (0.05 ) $ (0.05 )

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Event	12. Subsequent Event During the first quarter of 2016, the Company raised net proceeds (net of commissions) of approximately $494,000 from the sale of 226,698 shares of the Company’s common stock in the open market through the November 2015 Controlled Equity Offering agreement with Cantor Fitzgerald at a weighted average price of $2.25 per share. As of February 18, 2016, the Company had up to $37.6 million of common stock available for sale under the Controlled Equity Offering program and $122.6 million of common stock available for sale under its shelf registration statement.

Schedule II-Valuation and Quali

Schedule II-Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule II-Valuation and Qualifying Accounts	SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS Year Ended December 31, 2015, 2014 and 2013 (in thousands) Balance at Provision Recoveries/ Balance at December 31, 2015 Allowance for doubtful accounts $ 211 $ (38 ) $ (12 ) $ 161 December 31, 2014 Allowance for doubtful accounts $ 144 $ 88 $ (21 ) $ 211 December 31, 2013 Allowance for doubtful accounts $ 154 $ (20 ) $ 10 $ 144

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
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 developing therapies based on its proprietary drug formulations and delivery platform technologies and its expertise in drug development. 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). Certain other expense balances on the statements of operations and comprehensive income (loss) have been reclassified to conform to the current period presentation. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements, the reported amounts of revenue and expenses during the reported period and related disclosures. Actual results could differ materially from those estimates.
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 and 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 within management’s expectations.
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 REMOXY and another product. In 2015, revenue from the ALZET product line and the LACTEL product line accounted for 36% and 22% of total revenue, respectively. In 2014, revenue from the ALZET product line and the LACTEL product line accounted for 37% and 19% of total revenue, respectively. In 2013, revenue from the ALZET product line and the LACTEL product line accounted for 48% and 26% of total revenue, respectively. In 2015, Zogenix and Tolmar accounted for 26% and 11% of the Company’s total revenues. In 2014, Zogenix and Impax accounted for 23% and 11% of the Company’s total revenues. In 2013, Tolmar accounted for 15% of the Company’s total revenues. Total revenue by geographic region for the years 2015, 2014 and 2013 are as follows (in thousands): Year ended December 31, 2015 2014 2013 United States $ 14,289 $ 15,532 $ 11,087 Japan 1,897 898 1,104 Europe 1,817 1,986 2,089 Other 1,121 985 1,046 Total $ 19,124 $ 19,401 $ 15,326 Revenue by geography is determined by the location of the customer.
Inventories	Inventories Inventories are stated at the lower of cost or market, with cost determined on a first-in, first-out basis. Inventories, in part, include certain excipients that are sold to a customer and included in products awaiting regulatory approval. These inventories are capitalized based on management’s judgment of probable sale prior to their expiration date which in turn is primarily based on non-binding forecasts from our customers as well as management’s internal estimates. The valuation of inventory requires management to estimate the value of inventory that may become expired prior to use. The Company may be required to expense previously capitalized inventory costs upon a change in management’s judgment, due to, among other potential factors, a denial or delay of approval of a customer’s product by the necessary regulatory bodies, or new information that suggests that the inventory will not be saleable. In addition, these circumstances may cause the Company to record a liability related to minimum purchase agreements that the Company has in place for raw materials. In 2014, the Company recorded charges to cost of goods sold of approximately $1.6 million, of which approximately $1.1 million related to the write-down of the cost basis of inventory and $500,000 related to the accrual of a liability for the minimum purchase commitment for the excipients. As of December 31, 2015, the remaining carrying value of the excipients in the Company’s inventory was $1.1 million. In addition, the Company has remaining unrecorded future purchase commitments totaling $1.5 million through 2018. 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 and a reserve for future purchase commitments. The Company’s inventories consisted of the following (in thousands): December 31, 2015 2014 Raw materials $ 1,168 $ 1,242 Work in-process 1,412 1,120 Finished goods 1,337 1,280 Total inventories $ 3,917 $ 3,642
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.
Acquired Intangible Assets and Goodwill	Acquired Intangible Assets and Goodwill Acquired intangible assets consist of patents, developed technology, trademarks and customer lists related to the Company’s acquisitions accounted for using the purchase method. Amortization of these purchased intangibles is calculated on a straight-line basis over the respective estimated useful lives of the assets ranging from four to seven years. The Company assesses goodwill for impairment at least annually.
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, 2015, 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 Revenue from the sale of products is recognized when there is persuasive evidence that an arrangement exists, the product is shipped and title transfers to customers, provided no continuing obligation on the Company’s part exists, the price is fixed or determinable and the collectability of the amounts owed is reasonably assured. The Company enters into license and collaboration agreements under which it may receive upfront license fees, research funding and contingent milestone payments and royalties. The Company’s deliverables under these arrangements typically consist of granting licenses to intellectual property rights and providing research and development services. The accounting standards contain a presumption that separate contracts entered into at or near the same time with the same entity or related parties were negotiated as a package and should be evaluated as a single agreement. For multiple element arrangements entered into prior to January 1, 2011, the Company determined whether the elements had value on a stand-alone basis and whether there was objective and reliable evidence of fair value. When the delivered element did not have stand-alone value or there was insufficient evidence of fair value for the undelivered element(s), 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 are 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 represents 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. Returns or credits related to the sale of products have not had a material impact on the Company’s revenues or net loss. Research and development revenue related to services performed under the collaborative arrangements with the Company’s third-party collaborators is recognized as the related research and development services are performed. These research payments received under each respective agreement are not refundable and are generally based on reimbursement of qualified expenses, as defined in the agreements. Research and development expenses under the collaborative research and development agreements generally approximate or exceed the revenue recognized under such agreements over the term of the respective agreements. Deferred revenue may result when the Company does not expend the required level of effort during a specific period in comparison to funds received under the respective agreement. For joint control and funding development activities, the Company recognizes revenue from the net reimbursement of the research and development expenses from our collaborators and records the net payment of research and development expenses to our collaborators as additional research and development expense. Milestone payments under collaborative arrangements are triggered either by the results of the Company’s research and development efforts or by specified sales results by a third-party collaborator. Milestones related to the Company’s development-based activities may include initiation of various phases of clinical trials, successful completion of a phase of development or results from a clinical trial, acceptance of a New Drug Application by the FDA or an equivalent filing with an equivalent regulatory agency in another territory, or regulatory approval by the FDA or by an equivalent regulatory agency in another territory. Due to the uncertainty involved in meeting these development-based milestones, the development-based milestones are considered to be substantial (i.e., not just achieved through passage of time) at the inception of the collaboration agreement. In addition, the amounts of the payments assigned thereto are considered to be commensurate with the enhancement of the value of the delivered intellectual property as a result of the Company’s performance. The Company’s involvement is necessary to the achievement of development-based milestones. The Company would account for development-based milestones as revenue upon achievement of the substantive milestone events. Milestones related to sales-based activities may be triggered upon events such as the first commercial sale of a product or when sales first achieve a defined level. Under the Company’s collaborative agreements, the Company’s third-party collaborators will take the lead in commercialization activities and the Company is typically not involved in the achievement of sales-based milestones. These sales-based milestones would be achieved after the completion of the Company’s development activities. The Company would account for the sales-based milestones in the same manner as royalties, with revenue recognized upon achievement of the milestone. In addition, upon the achievement of either development-based or sales-based milestone events, the Company has no future performance obligations related to any milestone payments. Revenue on cost-plus-fee contracts, such as under contracts to perform research and development for others, is recognized as the related services are rendered as determined by the extent of reimbursable costs incurred plus estimated fees thereon.
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, net reimbursements of research and development expenses incurred by the Company’s partners are recorded as collaborative research and development revenue. Net payments of research and development expenses to the Company’s partners are recorded as an addition to research and development expenses in the period incurred.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Accumulated other comprehensive income (loss) as of December 31, 2015, 2014 and 2013 is entirely comprised of unrealized gains or losses on available-for-sale securities.
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 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 and warrants to purchase common stock) outstanding during the period, if dilutive, using the treasury stock method for options and warrants. 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, 2015 2014 2013 Numerators: Net loss $ (22,663 ) $ (22,110 ) $ (21,452 ) Denominators: Weighted average shares used to compute basic net loss per share 118,523 111,666 103,078 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute basic net loss per share 118,523 111,666 103,078 Net loss per share: Basic $ (0.19 ) $ (0.20 ) $ (0.21 ) Diluted $ (0.19 ) $ (0.20 ) $ (0.21 ) The computation of diluted net loss per share for the years ended December 31, 2015, 2014 and 2013 excludes the impact of options to purchase 16.5 million, 20.0 million and 19.6 million shares of common stock outstanding, respectively, at December 31, 2015, 2014 and 2013, 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 May 2014, the Financial Accounting Standards Board (FASB) issued guidance codified in ASC 606, Revenue Recognition—Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The guidance provides companies with two implementation methods. Companies can choose to apply the standard retrospectively to each prior reporting period presented (full retrospective application) or retrospectively with the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings of the annual reporting period that includes the date of initial application (modified retrospective application). The standard was to have been effective for public entities for annual and interim periods beginning after December 15, 2016. In July 2015, the FASB voted to delay the effective date for this guidance. This guidance is effective for the Company in the first quarter of 2018. Early adoption up to the first quarter of 2017 is permitted. The Company is currently evaluating the impact of the provisions of ASC 606. In August 2014, the FASB issued Accounting Standards Update 2014-15, Presentation of Financial Statements – Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (ASU 2014-15). This update is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 requires management to assess an entity’s ability to continue as a going concern by incorporating and expanding upon certain principles that are currently in U.S. auditing standards. Specifically, the amendments: (1) provide a definition of the term substantial doubt; (2) require an evaluation every reporting period including interim periods; (3) provide principles for considering the mitigating effect of management’s plans; (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans; (5) require an express statement and other disclosures when substantial doubt is not alleviated; and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 will be effective for annual periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016, with early adoption permitted. ASU 2014-15 will be effective for the Company beginning with its annual report for fiscal 2016 and interim periods thereafter. The Company is currently evaluating the impact that ASU 2014-15 will have on its financial statements. In November 2015, the FASB issued Accounting Standards Update 2015-17(ASU 2015-17), Balance Sheet Classification of Deferred Taxes to simplify the presentation of deferred income taxes. The amendments in this update require that deferred tax liabilities and assets be classified as noncurrent on the balance sheet instead of separating deferred taxes into current and noncurrent amounts. The new guidance will be effective for public business entities in fiscal years beginning after December 15, 2016, including interim periods within those years (i.e., in the first quarter of 2017 for calendar year-end companies). Early adoption is permitted for all entities as of the beginning of an interim or annual reporting period. The guidance may be applied either prospectively, for all deferred tax assets and liabilities, or retrospectively (i.e., by reclassifying the comparative balance sheet). The Company has elected to early adopt ASU 2015-17, on a prospective basis, for the year ended December 31, 2015. Prior periods were not retrospectively adjusted. There is no impact to the balance sheet amounts as a result of early adoption.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Total Revenue by Geographic Region	Total revenue by geographic region for the years 2015, 2014 and 2013 are as follows (in thousands): Year ended December 31, 2015 2014 2013 United States $ 14,289 $ 15,532 $ 11,087 Japan 1,897 898 1,104 Europe 1,817 1,986 2,089 Other 1,121 985 1,046 Total $ 19,124 $ 19,401 $ 15,326
Summary of Components of Inventories	The Company’s inventories consisted of the following (in thousands): December 31, 2015 2014 Raw materials $ 1,168 $ 1,242 Work in-process 1,412 1,120 Finished goods 1,337 1,280 Total inventories $ 3,917 $ 3,642
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, 2015 2014 2013 Numerators: Net loss $ (22,663 ) $ (22,110 ) $ (21,452 ) Denominators: Weighted average shares used to compute basic net loss per share 118,523 111,666 103,078 Effect of dilutive securities: Dilution from stock options — — — Dilution from ESPP — — — Dilutive common shares — — — Weighted average shares used to compute basic net loss per share 118,523 111,666 103,078 Net loss per share: Basic $ (0.19 ) $ (0.20 ) $ (0.21 ) Diluted $ (0.19 ) $ (0.20 ) $ (0.21 )

Strategic Agreements (Tables)

Strategic Agreements (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 2014 2013 Collaborator Zogenix, Inc. (Zogenix) (1) $ 4,898 $ 4,431 $ 918 Pain Therapeutics, Inc. (Pain Therapeutics) 1,385 1,359 750 Santen Pharmaceutical Co. Ltd. (Santen) (2) 824 16 — Impax Laboratories, Inc. (Impax) (3) — 2,106 — Pfizer Inc. (Pfizer) — 118 42 Others 725 226 1,880 Total collaborative research and development and other revenue $ 7,832 $ 8,256 $ 3,590 (1) Amounts related to ratable recognition of upfront fees were $255,000 in 2015 and 2014, and $241,000 in 2013. (2) Amounts related to ratable recognition of upfront fees were $274,000 in 2015, $15,000 in 2014, and zero in 2013, respectively; the Company and Santen signed a license agreement effective December 11, 2014. (3) Amounts related to recognition of upfront fees were zero in 2015, $2.0 million in 2014 and zero in 2013, respectively; the Company and Impax signed a license agreement effective January 3, 2014.
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, 2015 were $19.3 million under these agreements. Year Ended December 31, 2015 2014 2013 Ratable recognition of upfront payment $ 255 $ 255 $ 241 Research and development expenses reimbursable by Zogenix 4,643 4,176 677 Total collaborative research and development revenue $ 4,898 $ 4,431 $ 918
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, 2015 2014 2013 Ratable recognition of upfront payment $ 274 $ 15 $ — Research and development expenses reimbursable by Santen 550 1 — Total collaborative research and development revenue $ 824 $ 16 $ —
Agreement with Impax Laboratories, 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 Impax Agreement (in thousands). The cumulative aggregate payments received by the Company as of December 31, 2015 were $2.1 million under the agreement. Year Ended December 31, 2015 2014 2013 Ratable recognition of upfront payment $ — $ 2,000 $ — Research and development expenses reimbursable by Impax — 106 — Total collaborative research and development revenue $ — $ 2,106 $ —

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 81 $ — $ — $ 81 Certificates of deposit — 250 — 250 Commercial paper — 898 — 898 Corporate debt — 5,211 — 5,211 U.S. Government agencies — 19,548 — 19,548 Total $ 81 $ 25,907 $ — $ 25,988 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, 2014 (in thousands): Level 1 Level 2 Level 3 Total Money market funds $ 1,558 $ — $ — $ 1,558 Certificates of deposit — 350 — 350 Marketable equity security 155 — — 155 Commercial paper — 1,250 — 1,250 Corporate debt — 7,740 — 7,740 U.S. Government agencies — 22,675 — 22,675 Total $ 1,713 $ 32,015 $ — $ 33,728
Summary of Money Market Funds and Available-for-Sale Securities	The following is a summary of available-for-sale securities as of December 31, 2015 and 2014 (in thousands): December 31, 2015 Amortized Unrealized Unrealized Estimated Money market funds $ 81 $ — $ — $ 81 Certificates of deposit 250 — — 250 Commercial paper 898 — — 898 Corporate debt 5,215 1 (5 ) 5,211 U.S. Government agencies 19,558 1 (11 ) 19,548 $ 26,002 $ 2 $ (16 ) $ 25,988 Reported as: Cash and cash equivalents $ 281 $ — $ — $ 281 Short-term investments 25,471 2 (16 ) 25,457 Long-term restricted investments 250 — — 250 $ 26,002 $ 2 $ (16 ) $ 25,988 December 31, 2014 Amortized Unrealized Unrealized Estimated Money market funds $ 1,558 $ — $ — $ 1,558 Certificates of deposit 350 — — 350 Marketable equity security — 155 — 155 Commercial paper 1,250 — — 1,250 Corporate debt 7,744 — (4 ) 7,740 U.S. Government agencies 22,678 2 (5 ) 22,675 $ 33,580 $ 157 $ (9 ) $ 33,728 Reported as: Cash and cash equivalents $ 1,558 $ — $ — $ 1,558 Short-term investments 29,867 157 (8 ) 30,016 Long-term investments 1,805 — (1 ) 1,804 Long-term restricted investments 350 — — 350 $ 33,580 $ 157 $ (9 ) $ 33,728
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, 2015, by contractual maturity (in thousands): December 31, 2015 Amortized Estimated Mature in one year or less $ 25,921 $ 25,907 Mature after one year through five years — — $ 25,921 $ 25,907

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and equipment consist of the following (in thousands): December 31, 2015 2014 Equipment $ 12,372 $ 12,161 Leasehold improvement 9,987 9,968 Construction-in-progress 178 227 22,537 22,356 Less accumulated depreciation and amortization (20,971 ) (20,607 ) Property and equipment, net $ 1,566 $ 1,749

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Schedule of Future Operating Lease Minimum Payments	Future minimum payments under these noncancelable leases are as follows (in thousands): Year ending December 31, Operating 2016 $ 1,970 2017 2,000 2018 1,948 2019 539 Thereafter 518 $ 6,975

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2015
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, 2015, are as follows (in thousands): 2016 $ 1,590 2017 8,848 2018 8,848 2019 6,423 Total minimum payments 25,709 Less amount representing interest (5,709 ) Gross balance of long-term debt 20,000 Less unamortized debt discount (316 ) Carrying value of long-term debt 19,684 Less current portion of long-term debt — Long-term debt, less current portion and unamortized debt discount $ 19,684

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Shares of Common Stock Reserved for Future Issuance	As of December 31, 2015, shares of common stock reserved for future issuance consisted of the following: December 31, Stock options outstanding 27,298,453 Stock options available for grant 2,405,807 Employee Stock Purchase Plan 366,340 30,070,600
Summary of Stock Option Activity under all Stock-Based Compensation Plans	A summary of stock option activity under all stock-based compensation plans is as follows: Number of Weighted Weighted Aggregate Outstanding at December 31, 2012 20,902,156 $ 3.07 5.41 $ — Options granted 4,592,849 $ 1.21 Options exercised (187,014 ) $ 1.01 Options forfeited (94,055 ) $ 1.38 Options expired (1,517,352 ) $ 3.17 Outstanding at December 31, 2013 23,696,584 $ 2.73 5.45 $ 5.2 Options granted 3,747,428 $ 1.94 Options exercised (300,602 ) $ 0.99 Options forfeited (144,611 ) $ 1.50 Options expired (2,758,960 ) $ 2.95 Outstanding at December 31, 2014 24,239,839 $ 2.61 5.72 $ — Options granted 4,299,290 $ 1.09 Options exercised (925,636 ) $ 1.13 Options forfeited (15,990 ) $ 1.34 Options expired (299,050 ) $ 3.58 Outstanding at December 31, 2015 27,298,453 $ 2.41 5.39 $ 13.5 Exercisable at December 31, 2015 23,222,277 $ 2.59 4.86 $ 10.1 Vested and expected to vest at December 31, 2015 27,028,688 $ 2.42 5.36 $ 13.2
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, 2015 2014 2013 Cost of product revenues $ 108 $ 149 $ 170 Research and development 1,400 1,697 1,999 Selling, general and administrative 1,152 1,234 1,257 $ 2,660 $ 3,080 $ 3,426
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 2015 and 2014, and February 2013) and shares purchased under its stock plans and employee stock purchase plan for the years ended December 31, 2015, 2014 and 2013: Year ended December 31, 2015 2014 2013 Stock Options Risk-free rate 1.5-2.4 % 1.9-2.8 % 0.9-2.9 % Expected dividend yield — — — Expected term (in years) 6.5-10.0 6.5-10.0 5.3-10.0 Volatility 78-85 % 76-85 % 77-86 % Forfeiture rate 6.0 % 7.2 % 8.4 % Year ended December 31, 2015 2014 2013 Employee Stock Purchase Plan Risk-free rate 0.1-0.3 % 0.1 % 0.1-0.2 % Expected dividend yield — — — Expected term (in years) 0.5 0.5 0.5 Volatility 68-95 % 60-81 % 64-81 %
Summary of Stock Options Outstanding	The following table summarizes information about stock options outstanding at December 31, 2015: Options Outstanding Options Exercisable Range of Number of Weighted- Weighted- Number of Weighted- $0.73 – 0.87 2,494,482 6.18 $ 0.78 2,346,554 $ 0.78 $0.88 – 0.88 3,235,932 9.02 $ 0.88 1,631,647 $ 0.88 $1.00 – 1.20 388,855 7.63 $ 1.08 310,292 $ 1.10 $1.21 – 1.21 3,537,417 7.09 $ 1.21 3,015,494 $ 1.21 $1.24 – 1.93 1,436,463 8.16 $ 1.46 1,033,358 $ 1.46 $2.09 – 2.09 3,956,166 6.73 $ 2.09 2,949,018 $ 2.09 $2.13 – 2.77 2,739,429 4.32 $ 2.22 2,636,205 $ 2.21 $2.80 – 3.26 4,166,269 4.38 $ 3.16 3,956,269 $ 3.18 $3.29 – 5.27 3,695,694 0.81 $ 4.59 3,695,694 $ 4.59 $5.38 – 6.32 1,647,746 1.92 $ 5.91 1,647,746 $ 5.91 $0.73 – 6.32 27,298,453 5.39 $ 2.41 23,222,277 $ 2.59

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
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 34% to net income tax benefit included in the statements of operations and comprehensive loss for the years ended December 31, 2015, 2014 and 2013 is as follows (in thousands): Year Ended December 31, 2015 2014 2013 U.S. federal taxes provision (benefit) at statutory rate $ (7,681 ) $ (7,502 ) $ (7,184 ) State taxes — — — Change in valuation allowance 7,725 6,854 9,517 Stock-based compensation 530 1,139 375 Change in deferreds 56 (2 ) (1,718 ) Other (577 ) (465 ) (670 ) Total income tax provision $ 53 $ 24 $ 320
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, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 111,696 $ 105,609 Research and other credits 12,001 10,995 Capitalized research and development expenses 132 456 Deferred revenue 1,045 516 Stock-based compensation 9,605 9,402 Other 3,645 3,967 Total deferred tax assets 138,124 130,945 Valuation allowance for deferred tax assets (138,124 ) (130,945 ) Deferred tax liabilities—Intangibles (397 ) (405 ) Net deferred tax assets and liabilities $ (397 ) $ (405 )
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): December 31, 2015 2014 Balance at beginning of the year $ 5,702 $ 5,252 Increases (decrease) related to prior year tax positions 737 — Increases (decrease) related to current year tax positions 526 450 Settlements — — Reductions due to lapse of applicable statute of limitations — — Balance at end of the year $ 6,965 $ 5,702

Unaudited Selected Quarterly 30

Unaudited Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	First Quarter Second Quarter Third Quarter Fourth Quarter 2015 2014 2015 2014 2015 2014 2015 2014 Revenue $ 4,773 $ 6,293 $ 4,441 $ 4,581 $ 4,743 $ 4,258 $ 5,167 $ 4,269 Net loss $ (4,853 ) $ (3,600 ) $ (5,478 ) $ (5,478 ) $ (6,487 ) $ (7,092 ) $ (5,845 ) $ (5,940 ) Basic net loss per share $ (0.04 ) $ (0.03 ) $ (0.05 ) $ (0.05 ) $ (0.05 ) $ (0.06 ) $ (0.05 ) $ (0.05 ) Diluted net loss per share $ (0.04 ) $ (0.03 ) $ (0.05 ) $ (0.05 ) $ (0.05 ) $ (0.06 ) $ (0.05 ) $ (0.05 )

Summary of Significant Accoun31

Summary of Significant Accounting Policies - Additional Information (Detail) shares in Millions	12 Months Ended
	Dec. 31, 2015USD ($)Segmentshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)shares
Summary Of Significant Accounting Policies [Line Items]
State of incorporation	Delaware
Date of incorporation	Feb. 6, 1998
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
Cost of goods sold	3,905,000	$ 5,686,000	$ 4,837,000
Write-down of the cost basis of inventory	303,000	1,227,000	$ 574,000
Minimum purchase commitment	500,000
Inventories	3,917,000	$ 3,642,000
Long-lived assets, impairment losses	$ 0
Number of operating segment | Segment	1
Options to purchase common stock excluded from computation of diluted net loss per share | shares	16.5	20	19.6
Agreement with Pain Therapeutics, Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Cost of goods sold	$ 1,600,000
Write-down of the cost basis of inventory	1,100,000
Minimum purchase commitment	500,000
Inventories	1,100,000
Remaining unrecorded future purchase commitments	$ 1,500,000
Sales Revenue Net [Member] | Zogenix [Member] | Customer Concentration Risk [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted in Company's total revenue	26.00%	23.00%
Sales Revenue Net [Member] | Impax [Member] | Customer Concentration Risk [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted in Company's total revenue		11.00%
Sales Revenue Net [Member] | Tolmar Inc. [Member] | Customer Concentration Risk [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted in Company's total revenue	11.00%		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	36.00%	37.00%	48.00%
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	22.00%	19.00%	26.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Short-term investments maturity period	90 days
Property and equipment, estimated useful life	3 years
Acquired intangible assets, estimated useful life	4 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Short-term investments maturity period	1 year
Property and equipment, estimated useful life	5 years
Acquired intangible assets, estimated useful life	7 years

Summary of Significant Accoun32

Summary of Significant Accounting Policies - Summary of Total Revenue by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 5,167	$ 4,743	$ 4,441	$ 4,773	$ 4,269	$ 4,258	$ 4,581	$ 6,293	$ 19,124	$ 19,401	$ 15,326
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									14,289	15,532	11,087
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,897	898	1,104
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,817	1,986	2,089
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 1,121	$ 985	$ 1,046

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Summary of Components of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory, Net [Abstract]
Raw materials	$ 1,168	$ 1,242
Work in-process	1,412	1,120
Finished goods	1,337	1,280
Total inventories	$ 3,917	$ 3,642

Summary of Significant Accoun34

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, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerators:
Net loss	$ (5,845)	$ (6,487)	$ (5,478)	$ (4,853)	$ (5,940)	$ (7,092)	$ (5,478)	$ (3,600)	$ (22,663)	$ (22,110)	$ (21,452)
Denominators:
Weighted average shares used to compute basic net loss per share									118,523	111,666	103,078
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 basic net loss per share									118,523	111,666	103,078
Net loss per share:
Basic									$ (0.19)	$ (0.20)	$ (0.21)
Diluted	$ (0.05)	$ (0.05)	$ (0.05)	$ (0.04)	$ (0.05)	$ (0.06)	$ (0.05)	$ (0.03)	$ (0.19)	$ (0.20)	$ (0.21)

Strategic Agreements - Summary

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	$ 7,832,000	$ 8,256,000	$ 3,590,000
Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	4,898,000	4,431,000	918,000
Agreement with Impax Laboratories, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		2,106,000
Agreement with Pain Therapeutics, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	1,385,000	1,359,000	750,000
Agreement with Pfizer [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	0	118,000	42,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	824,000	16,000
Agreements With Other Third Party Collaborators [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue	$ 725,000	$ 226,000	$ 1,880,000

Strategic Agreements - Summar36

Strategic Agreements - Summary of Collaborative Research and Development and Other Revenues Associated with Company's Major Third-Party Collaborators (Parenthetical) (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amounts related to the ratable recognition of upfront fees		$ 255	$ 255	$ 241
Agreement with Impax Laboratories, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amounts related to the ratable recognition of upfront fees		0	2,000	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	$ 274	$ 15	$ 0

Strategic Agreements - Addition

Strategic Agreements - Additional Information (Detail) - USD ($)	2 Months Ended	12 Months Ended
	Feb. 18, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments		$ 245,500,000
Milestone payments received		0
Subsequent event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payments received	$ 0
Development-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments		77,500,000
Sales-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments		168,000,000
Early stage clinical testing [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones		5,000,000
Late stage clinical testing [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones		12,500,000
Regulatory filings [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones		20,500,000
Regulatory approvals [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development-based milestones		$ 39,500,000

Strategic Agreements - Agreemen

Strategic Agreements - Agreement with Pain Therapeutics, Inc. - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Dec. 31, 2002Drug	Dec. 31, 2015USD ($)License	Dec. 31, 2014USD ($)Drug	Dec. 31, 2013USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		$ 7,832,000	$ 8,256,000	$ 3,590,000
Revenue recognition milestone achieved		245,500,000
Product revenue, net		11,292,000	11,145,000	11,736,000
Cost of goods sold		3,905,000	$ 5,686,000	4,837,000
Agreement with Pain Therapeutics, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of specified opioid drugs | Drug	4		3
Total collaborative research and development and other revenue		$ 1,385,000	$ 1,359,000	750,000
Number of remaining licensed products | License		3
Performance milestone payments based on successful development		$ 7,200,000	7,200,000
Cumulative aggregate payments received by the Company			38,500,000
Upfront license fee		1,000,000
Cost of goods sold		1,600,000
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		7,200,000
Revenue recognition milestone achieved		1,700,000
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
Agreement with Pfizer [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development and other revenue		0	118,000	42,000
Cumulative aggregate payments received by the Company		7,100,000
Product revenue, net		96,000	33,000	273,000
Cost of goods sold		$ 51,000	$ 0	$ 165,000

Strategic Agreements - Agreem39

Strategic Agreements - Agreement with Zogenix, Inc. - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2011	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognition milestone achieved		$ 245,500,000
Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments		$ 103,000,000
Patent royalty term		15 years
Cumulative aggregate payments received by the Company		$ 19,300,000
Agreement with Zogenix, Inc. [Member] | Development-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments		28,000,000
Revenue recognition milestone achieved		0
Agreement with Zogenix, Inc. [Member] | Sales-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments		75,000,000
Revenue recognition milestone achieved		0
Up-front Payment Arrangement [Member] | Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable upfront fee	$ 2,250,000	$ 2,250,000

Strategic Agreements - Summar40

Strategic Agreements - Summary of Collaborative Research and Development Revenue Recognized (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaborative research and development revenue		$ 7,832	$ 8,256	$ 3,590
Agreement with Zogenix, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ratable recognition of upfront payment		255	255	241
Research and development expenses reimbursable by the Company		4,643	4,176	677
Total collaborative research and development revenue		4,898	4,431	918
Agreement with Impax Laboratories, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ratable recognition of upfront payment		0	2,000	0
Research and development expenses reimbursable by the Company			106
Total collaborative research and development revenue			2,106
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ratable recognition of upfront payment	$ 0	274	15	$ 0
Research and development expenses reimbursable by the Company		550	1
Total collaborative research and development revenue		$ 824	$ 16

Strategic Agreements - Agreem41

Strategic Agreements - Agreement with Impax Laboratories, Inc. - Additional Information (Detail) - USD ($)	Jan. 03, 2014	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognition milestone achieved		$ 245,500,000
Agreement with Impax Laboratories, Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable upfront fee	$ 2,000,000
Future milestone payments	61,000,000
Cumulative aggregate payments received by the Company		2,100,000
Agreement with Impax Laboratories, Inc. [Member] | Development-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments	31,000,000
Agreement with Impax Laboratories, Inc. [Member] | Sales-Based Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments	$ 30,000,000
Revenue recognition milestone achieved		$ 0

Strategic Agreements - Agreem42

Strategic Agreements - Agreement with Santen Pharmaceutical Co., Ltd. - Additional Information (Detail) - USD ($)	Dec. 11, 2014	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognition milestone achieved		$ 245,500,000
Agreement with Santen Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront license fee	$ 2,000,000
Future milestone payments	76,000,000
Cumulative aggregate payments received by the Company		2,400,000
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

Intangible Assets and Goodwill

Intangible Assets and Goodwill - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Net amount of intangible assets	$ 0	$ 0
Goodwill	6,399,000	6,399,000
Goodwill impairment	$ 0	$ 0	$ 0
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, estimated useful life	4 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, estimated useful life	7 years

Financial Instruments - Fair Va

Financial Instruments - Fair Value Measurements of Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 25,988	$ 33,728
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	81	1,558
Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	250	350
Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	898	1,250
Corporate debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	5,211	7,740
U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	19,548	22,675
Marketable equity security [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total		155
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	81	1,713
Level 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	81	1,558
Level 1 [Member] | Marketable equity security [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total		155
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	25,907	32,015
Level 2 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	250	350
Level 2 [Member] | Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	898	1,250
Level 2 [Member] | Corporate debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	5,211	7,740
Level 2 [Member] | U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 19,548	$ 22,675

Financial Instruments - Summary

Financial Instruments - Summary of Money Market Funds and Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 26,002	$ 33,580
Unrealized Gain	2	157
Unrealized Loss	(16)	(9)
Estimated Fair Value	25,988	33,728
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	81	1,558
Estimated Fair Value	81	1,558
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	250	350
Estimated Fair Value	250	350
Marketable equity security [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gain		155
Estimated Fair Value		155
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	898	1,250
Estimated Fair Value	898	1,250
Corporate debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,215	7,744
Unrealized Gain	1
Unrealized Loss	(5)	(4)
Estimated Fair Value	5,211	7,740
U.S. Government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,558	22,678
Unrealized Gain	1	2
Unrealized Loss	(11)	(5)
Estimated Fair Value	19,548	22,675
Cash and cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	281	1,558
Estimated Fair Value	281	1,558
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25,471	29,867
Unrealized Gain	2	157
Unrealized Loss	(16)	(8)
Estimated Fair Value	25,457	30,016
Long-term restricted investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	250	350
Estimated Fair Value	$ 250	350
Long-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,805
Unrealized Loss		(1)
Estimated Fair Value		$ 1,804

Financial Instruments - Summa46

Financial Instruments - Summary of Cost and Estimated Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Investments, Debt and Equity Securities [Abstract]
Mature in one year or less, Amortized Cost	$ 25,921
Mature after one year through five years, Amortized Cost	0
Amortized Cost	25,921
Mature in one year or less, Estimated Fair Value	25,907
Mature after one year through five years, Estimated Fair Value	0
Estimated Fair Value	$ 25,907

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail)	Dec. 31, 2015USD ($)
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, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 22,537	$ 22,356
Less accumulated depreciation and amortization	(20,971)	(20,607)
Property and equipment, net	1,566	1,749
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,372	12,161
Leasehold improvement [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,987	9,968
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 178	$ 227

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 425,000	$ 582,000	$ 541,000
Amortization expense	1,000	$ 17,000	$ 9,000
Restoration cost	$ 669,500

Restricted Investments - Additi

Restricted Investments - Additional Information (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Restricted Investments [Line Items]
Restricted investments in connection with deposits on letters of credit	$ 250,000	$ 350,000
Alabama and California [Member]
Restricted Investments [Line Items]
Restricted investments in connection with deposits on letters of credit	$ 250,000	$ 350,000

Commitments - Additional Inform

Commitments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Rent expenses of operating leases	$ 1,900,000	$ 1,800,000	$ 1,500,000
Remaining minimum purchase commitments	500,000
Accrued loss on purchase obligation	$ (500,000)

Commitments - Schedule of Futur

Commitments - Schedule of Future Operating Lease Minimum Payments (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Leases [Abstract]
2,015	$ 1,970
2,016	2,000
2,017	1,948
2,018	539
Thereafter	518
Total operating leases future minimum payments	$ 6,975

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Detail) - USD ($)	Jun. 26, 2014	Jul. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Proceeds from long term debt, net				$ 19,786,000
Loan modification fee		$ 240,000
Oxford Finance LLC Term Loan [Member]
Debt Instrument [Line Items]
Secured term loan	$ 20,000,000
Term loan, maturity date		Jul. 1, 2019	Jul. 1, 2018
Interest rate on term loan	7.95%
Percentage of an additional payment equal to principal amount	8.00%	10.00%	8.00%
Facility fee paid at final payment	$ 150,000
Term loan repayment description			The term loan repayment schedule provides for interest only payments for the first 18 months, followed by consecutive equal monthly payments of principal and interest in arrears starting on February 1, 2016
Proceeds from long term debt, net	19,800,000
Debt offering/issuance costs	$ 1,600,000
First principal payment date		Feb. 1, 2017	Feb. 1, 2016
Debt instrument, covenants in compliance			The Company was in compliance with all material covenants under the Loan Agreement and there had been no material adverse change.
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%

Long-Term Debt - Schedule of Fu

Long-Term Debt - Schedule of Future Maturities and Interest Payments under Term Loan (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Future maturities and interest payments under the term loan:
2,016	$ 1,590
2,017	8,848
2,018	8,848
2,019	6,423
Total minimum payments	25,709
Total minimum payments	25,709
Less amount representing interest	(5,709)
Gross balance of long-term debt	20,000
Gross balance of long-term debt	20,000
Less unamortized debt discount	(316)
Carrying value of long-term debt	19,684
Carrying value of long-term debt:
Carrying value of long-term debt	19,684
Less current portion of long-term debt	0
Long-term debt, less current portion and unamortized debt discount	$ 19,684	$ 19,824

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Nov. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered			$ 100,900	$ 125,000
Proceeds from sale of common stock, net of commission	$ 14,290	$ 4,618	10,675
Sale of common stock during period	7,066,607	2,907,664
Common stock weighted average price	$ 2.09	$ 1.65
Cantor Fitzgerald Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Securities offered			$ 25,000	$ 40,000

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
	Apr. 30, 2013	Mar. 31, 2000	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock upon equity financing, net of issuance cost			7,066,607	2,907,664
Reserved common stock for issuance			30,070,600
Options exercised, shares			4,299,290	3,747,428	4,592,849
Shares available for future grant			2,405,807
Common stock outstanding			27,298,453	24,239,839	23,696,584	20,902,156
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			5,500,000
Reserved common stock for issuance			29,294,260
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			2,405,807
Common stock outstanding			26,888,453
2000 Stock Plan [Member] | Non-employee director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options exercised, shares		30,000
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

Stockholders' Equity - 2000 Dir

Stockholders' Equity - 2000 Directors' Stock Option Plan - Additional Information (Detail) - shares	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Apr. 30, 2005	Mar. 31, 2000	Jun. 30, 2002	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares vested for annual option				27,028,688
Options exercised, shares				4,299,290	3,747,428	4,592,849
Common stock outstanding				27,298,453	24,239,839	23,696,584	20,902,156
Shares available for future grant				2,405,807
2000 Directors' Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options shares reserved for issuance	925,000	300,000	500,000
Vesting percentage per year		33.33%
Number of shares vested for annual option		5,000
Options exercised, shares	12,000	5,000	30,000
Stock option increase	425,000		200,000
Common stock outstanding				410,000
Shares available for future grant				0
2000 Directors' Stock Option Plan [Member] | Non-employee director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options shares reserved for issuance		20,000
Options exercised, shares		20,000

Stockholders' Equity - 2000 Emp

Stockholders' Equity - 2000 Employee Stock Purchase Plan - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2015	Jan. 31, 2014	Feb. 28, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share available for future grant		2,405,807
Common stock, shares issued		121,839,000	113,733,000
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
Options shares reserved for issuance		2,550,000
Share available for future grant		366,340				1,500,000	966,000	1,700,000
Common stock, shares issued		2,183,660
Intrinsic value of options exercised		$ 985,000	$ 178,000	$ 77,000
Weighted-average grant-date fair value of all options granted with exercise prices		$ 0.65	$ 1.53	$ 0.85

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shares of Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2015	Jan. 31, 2015	Dec. 31, 2014	Jan. 31, 2014	Dec. 31, 2013	Feb. 28, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding	27,298,453		24,239,839		23,696,584		20,902,156
Stock options available for grant	2,405,807
Shares of common stock reserved for future issuance	30,070,600
2000 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options available for grant	366,340	1,500,000		966,000		1,700,000
Shares of common stock reserved for future issuance	366,340

Stockholders' Equity - Summar60

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, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding, Number of Options, beginning balance	24,239,839	23,696,584	20,902,156
Options granted, Number of Options	4,299,290	3,747,428	4,592,849
Options exercised, Number of Options	(925,636)	(300,602)	(187,014)
Options forfeited, Number of Options	(15,990)	(144,611)	(94,055)
Options expired, Number of Options	(299,050)	(2,758,960)	(1,517,352)
Outstanding, Number of Options, ending balance	27,298,453	24,239,839	23,696,584	20,902,156
Outstanding, Number of Options, Weighted Average Exercise Price Per Share, beginning balance	$ 2.61	$ 2.73	$ 3.07
Exercisable, Number of Options	23,222,277
Options granted, Weighted Average Exercise Price Per Share	$ 1.09	1.94	1.21
Vested and expected to vest, Number of Options	27,028,688
Options exercised, Weighted Average Exercise Price Per Share	$ 1.13	0.99	1.01
Options forfeited, Weighted Average Exercise Price Per Share	1.34	1.50	1.38
Options expired, Weighted Average Exercise Price Per Share	3.58	2.95	3.17
Outstanding, Number of Options, Weighted Average Exercise Price Per Share, ending balance	2.41	$ 2.61	$ 2.73	$ 3.07
Exercisable, Number of Options, Weighted Average Exercise Price Per Share	2.59
Vested and expected to vest, Number of Options, Weighted Average Exercise Price Per Share	$ 2.42
Outstanding, Number of Options, Weighted Average Remaining Contractual Term	5 years 4 months 21 days	5 years 8 months 19 days	5 years 5 months 12 days	5 years 4 months 28 days
Exercisable, Number of Options, Weighted Average Remaining Contractual Term	4 years 10 months 10 days
Vested and expected to vest, Number of Options, Weighted Average Remaining Contractual Term	5 years 4 months 10 days
Outstanding, Number of Options, Aggregate Intrinsic Value	$ 13.5		$ 5.2
Exercisable, Number of Options, Aggregate Intrinsic Value	10.1
Vested and expected to vest, Number of Options, Aggregate Intrinsic Value	$ 13.2

Stockholders' Equity - Summar61

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, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	$ 2,660	$ 3,080	$ 3,426
Cost of product revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	108	149	170
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	1,400	1,697	1,999
Selling, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total employee stock-based compensation cost	$ 1,152	$ 1,234	$ 1,257

Stockholders' Equity - Determin

Stockholders' Equity - Determining Fair Value - Additional Information (Detail) - 2000 Employee Stock Purchase Plan [Member] - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
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	113,625	115,412	128,433
Recognition of expenses on shares purchased under employee stock purchase plan	$ 62,000	$ 43,000	$ 56,000
Expected total unrecognized compensation costs related to nonvested stock options	$ 3,500,000
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	$ 1,000,000	$ 299,000	$ 188,000

Stockholders' Equity - Summar63

Stockholders' Equity - Summary of Assumptions Used to Estimate Fair Value of Options Granted and Shares Purchased (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employees Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate, minimum	0.10%	0.10%	0.10%
Risk-free rate, maximum	0.30%		0.20%
Expected dividend yield	0.00%
Expected term (in years)	6 months	6 months	6 months
Volatility, minimum	68.00%	60.00%	64.00%
Volatility, maximum	95.00%	81.00%	81.00%
Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free rate, minimum	1.50%	1.90%	0.90%
Risk-free rate, maximum	2.40%	2.80%	2.90%
Volatility, minimum	78.00%	76.00%	77.00%
Volatility, maximum	85.00%	85.00%	86.00%
Forfeiture rate	6.00%	7.20%	8.40%
Stock Option Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 6 months	6 years 6 months	5 years 3 months 18 days
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

Stockholders' Equity - Summar64

Stockholders' Equity - Summary of Stock Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Range of Exercise Price, $0.73 - 0.87 [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	$ 0.87
Number of Options Outstanding | shares	2,494,482
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 2 months 5 days
Options Outstanding, Weighted-Average Exercise Price	$ 0.78
Number of Options Exercisable | shares	2,346,554
Options Exercisable, Weighted-Average Exercise Price	$ 0.78
Range of Exercise Price, $0.88 - 0.88 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	0.88
Options Outstanding, Range of Exercise Price, maximum	$ 0.88
Number of Options Outstanding | shares	3,235,932
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	9 years 7 days
Options Outstanding, Weighted-Average Exercise Price	$ 0.88
Number of Options Exercisable | shares	1,631,647
Options Exercisable, Weighted-Average Exercise Price	$ 0.88
Range of Exercise Price, $1.00 - 1.20 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	1
Options Outstanding, Range of Exercise Price, maximum	$ 1.20
Number of Options Outstanding | shares	388,855
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	7 years 7 months 17 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.08
Number of Options Exercisable | shares	310,292
Options Exercisable, Weighted-Average Exercise Price	$ 1.10
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	3,537,417
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	7 years 1 month 2 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.21
Number of Options Exercisable | shares	3,015,494
Options Exercisable, Weighted-Average Exercise Price	$ 1.21
Range of Exercise Price, $1.24 - 1.93 [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	$ 1.93
Number of Options Outstanding | shares	1,436,463
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	8 years 1 month 28 days
Options Outstanding, Weighted-Average Exercise Price	$ 1.46
Number of Options Exercisable | shares	1,033,358
Options Exercisable, Weighted-Average Exercise Price	$ 1.46
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	3,956,166
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	6 years 8 months 23 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.09
Number of Options Exercisable | shares	2,949,018
Options Exercisable, Weighted-Average Exercise Price	$ 2.09
Range of Exercise Price, $2.13 - 2.77 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	2.13
Options Outstanding, Range of Exercise Price, maximum	$ 2.77
Number of Options Outstanding | shares	2,739,429
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	4 years 3 months 26 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.22
Number of Options Exercisable | shares	2,636,205
Options Exercisable, Weighted-Average Exercise Price	$ 2.21
Range of Exercise Price, $2.80 - 3.26 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	2.80
Options Outstanding, Range of Exercise Price, maximum	$ 3.26
Number of Options Outstanding | shares	4,166,269
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	4 years 4 months 17 days
Options Outstanding, Weighted-Average Exercise Price	$ 3.16
Number of Options Exercisable | shares	3,956,269
Options Exercisable, Weighted-Average Exercise Price	$ 3.18
Range of Exercise Price, $3.29 - 5.27 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	3.29
Options Outstanding, Range of Exercise Price, maximum	$ 5.27
Number of Options Outstanding | shares	3,695,694
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	9 months 22 days
Options Outstanding, Weighted-Average Exercise Price	$ 4.59
Number of Options Exercisable | shares	3,695,694
Options Exercisable, Weighted-Average Exercise Price	$ 4.59
Range of Exercise Price, $5.38 - 6.32 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Range of Exercise Price, minimum	5.38
Options Outstanding, Range of Exercise Price, maximum	$ 6.32
Number of Options Outstanding | shares	1,647,746
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	1 year 11 months 1 day
Options Outstanding, Weighted-Average Exercise Price	$ 5.91
Number of Options Exercisable | shares	1,647,746
Options Exercisable, Weighted-Average Exercise Price	$ 5.91
Range of Exercise Price, $0.73 - 6.32 [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	$ 6.32
Number of Options Outstanding | shares	27,298,453
Options Outstanding, Weighted-Average Remaining Contractual Life(In years)	5 years 4 months 21 days
Options Outstanding, Weighted-Average Exercise Price	$ 2.41
Number of Options Exercisable | shares	23,222,277
Options Exercisable, Weighted-Average Exercise Price	$ 2.59

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Deferred tax liability	$ 397,000	$ 405,000
Income tax expenses related to unrealized gain on a marketable equity security	61,000
Deferred income tax provision (benefit)	$ (8,000)	$ 85,000	$ 320,000
Statutory federal income tax rate	34.00%	34.00%	34.00%
Total income tax provision	$ 53,000	$ 24,000	$ 320,000
Increase in valuation allowance of net deferred tax assets	7,200,000	8,900,000	11,700,000
Unrecognized tax benefits	6,965,000	5,702,000	5,252,000
Interest and penalty expense related to unrecognized tax benefits	0	0	0
Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards for income tax purposes	$ 295,600,000
Tax carryforwards expire date	2019 through 2035
Interest and other income (expenses) [Member]
Income Tax Contingency [Line Items]
Deferred income tax provision (benefit)	$ 53,000	$ 24,000	$ 320,000
State [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforwards for income tax purposes	$ 211,300,000
Tax carryforwards expire date	2015 through 2035
Research [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 9,900,000
Tax carryforwards expire date	2018 through 2035
Research [Member] | State [Member]
Income Tax Contingency [Line Items]
Research and development tax credits	$ 10,800,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expenses (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. federal taxes provision (benefit) at statutory rate	$ (7,681)	$ (7,502)	$ (7,184)
State taxes	0	0	0
Change in valuation allowance	7,725	6,854	9,517
Stock-based compensation	530	1,139	375
Change in deferreds	56	(2)	(1,718)
Other	(577)	(465)	(670)
Total income tax provision	$ 53	$ 24	$ 320

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Company's Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Components of Deferred Tax Assets [Abstract]
Net operating loss carryforwards	$ 111,696	$ 105,609
Research and other credits	12,001	10,995
Capitalized research and development expenses	132	456
Deferred revenue	1,045	516
Stock-based compensation	9,605	9,402
Other	3,645	3,967
Total deferred tax assets	138,124	130,945
Valuation allowance for deferred tax assets	(138,124)	(130,945)
Deferred tax liabilities-Intangibles	(397)	(405)
Net deferred tax assets and liabilities	$ (397)	$ (405)

Income Taxes - Reconciliation68

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 5,702	$ 5,252
Increases (decrease) related to prior year tax positions	737
Increases (decrease) related to current year tax positions	526	450
Settlements	0	0
Reductions due to lapse of applicable statute of limitations	0	0
Balance at end of the year	$ 6,965	$ 5,702

Unaudited Selected Quarterly 69

Unaudited Selected Quarterly Financial Data - Selected Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Revenue	$ 5,167	$ 4,743	$ 4,441	$ 4,773	$ 4,269	$ 4,258	$ 4,581	$ 6,293	$ 19,124	$ 19,401	$ 15,326
Net loss	$ (5,845)	$ (6,487)	$ (5,478)	$ (4,853)	$ (5,940)	$ (7,092)	$ (5,478)	$ (3,600)	$ (22,663)	$ (22,110)	$ (21,452)
Basic net loss per share	$ (0.05)	$ (0.05)	$ (0.05)	$ (0.04)	$ (0.05)	$ (0.06)	$ (0.05)	$ (0.03)
Diluted net loss per share	$ (0.05)	$ (0.05)	$ (0.05)	$ (0.04)	$ (0.05)	$ (0.06)	$ (0.05)	$ (0.03)	$ (0.19)	$ (0.20)	$ (0.21)

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 18, 2016	Nov. 30, 2015
Subsequent Event [Line Items]
Proceeds from sale of common stock, net of commission		$ 14,290,000	$ 4,618,000	$ 10,675,000
Sale of common stock during period		7,066,607	2,907,664
Common stock weighted average price		$ 2.09	$ 1.65
Securities offered				100,900,000		$ 125,000,000
Cantor Fitzgerald Co [Member]
Subsequent Event [Line Items]
Securities offered				$ 25,000,000		$ 40,000,000
Subsequent event [Member]
Subsequent Event [Line Items]
Securities offered					$ 122,600,000
Subsequent event [Member] | Cantor Fitzgerald Co [Member]
Subsequent Event [Line Items]
Securities offered					$ 37,600,000
Scenario, Forecast [Member]
Subsequent Event [Line Items]
Proceeds from sale of common stock, net of commission	$ 494,000
Sale of common stock during period	226,698
Common stock weighted average price	$ 2.25

Schedule II-Valuation and Qua71

Schedule II-Valuation and Qualifying Accounts (Detail) - Allowance for doubtful accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the year	$ 211	$ 144	$ 154
Provision	(38)	88	(20)
Recoveries/Write- Offs	(12)	(21)	10
Balance at end of the year	$ 161	$ 211	$ 144