Talphera (TLPH) 10-Q 10 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 24, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'ACRX	'
Entity Registrant Name	'ACELRX PHARMACEUTICALS INC	'
Entity Central Index Key	'0001427925	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	43,707,390

Condensed_Balance_Sheets

Condensed Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$70,241	$88,401	[1]
Short-term investments	15,329	15,262	[1]
Prepaid expenses and other current assets	1,071	897	[1]
Total current assets	86,641	104,560	[1]
Property and equipment, net	9,467	5,179	[1]
Restricted cash	250	250	[1]
Other assets	84	42	[1]
Total Assets	96,442	110,031	[1]
Current Liabilities:	'	'
Accounts payable	2,869	2,341	[1]
Accrued liabilities	2,036	3,904	[1]
Deferred revenue	952	623	[1]
Long-term debt, current portion	4,510	'
Total current liabilities	10,367	6,868	[1]
Deferred rent	303	188	[1]
Long-term debt, net of current portion	20,359	14,364	[1]
Deferred revenue	1,687	2,007	[1]
Contingent put option liability	325	334	[1]
Warrant liability	4,324	13,111	[1]
Total liabilities	37,365	36,872	[1]
Stockholders' Equity:	'	'
Common stock, $0.001 par value-100,000,000 shares authorized as of September 30, 2014 and December 31, 2013; 43,703,390 and 43,050,580 shares issued and outstanding as of September 30, 2014 and December 31, 2013	43	43	[1]
Additional paid-in capital	224,021	218,568	[1]
Accumulated deficit	-164,988	-145,453	[1]
Accumulated other comprehensive income	1	1	[1]
Total stockholders' equity	59,077	73,159	[1]
Total Liabilities and Stockholders' Equity	$96,442	$110,031	[1]
[1]	The condensed balance sheet as of December 31, 2013 has been derived from the audited financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.

Condensed_Balance_Sheets_Paren

Condensed Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]	'	'
Common stock, par value	$0.00	$0.00	[1]
Common stock, shares authorized	100,000,000	100,000,000	[1]
Common stock, shares issued	43,703,390	43,050,580	[1]
Common stock, shares outstanding	43,703,390	43,050,580	[1]
[1]	The condensed balance sheet as of December 31, 2013 has been derived from the audited financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.

Condensed_Statements_of_Compre

Condensed Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue:	'	'	'	'
Collaboration agreement	$4,825	'	$4,991	'
Research grant	0	548	0	1,895
Total revenue	4,825	548	4,991	1,895
Operating expenses:	'	'	'	'
Research and development	5,244	6,548	17,239	21,974
General and administrative	4,650	2,310	13,622	6,571
Total operating expenses	9,894	8,858	30,861	28,545
Loss from operations	-5,069	-8,310	-25,870	-26,650
Interest expense	-816	-348	-1,818	-1,205
Interest income and other income (expense), net	6,556	-2,328	8,153	-13,340
Net income (loss)	671	-10,986	-19,535	-41,195
Other comprehensive income (loss):	'	'	'	'
Unrealized gains (losses) on available-for-sale securities	1	5	-1	3
Comprehensive income (loss)	$672	($10,981)	($19,536)	($41,192)
Net income (loss) per share of common stock, basic	$0.02	($0.26)	($0.45)	($1.07)
Net loss per share of common stock, diluted	($0.13)	($0.26)	($0.63)	($1.07)
Shares used in computing net income (loss) per share of common stock, basic	43,469,354	41,462,425	43,332,013	38,635,370
Shares used in computing net loss per share of common stock, diluted-see Note 8	44,263,492	41,462,425	44,287,959	38,635,370

Condensed_Statements_of_Cash_F

Condensed Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Cash flows from operating activities:	'		'
Net loss	($19,535)		($41,195)
Adjustments to reconcile net loss to net cash used in operating activities:	'		'
Depreciation and amortization	469		439
Amortization of premium/discount on investments, net	187		134
Interest expense related to debt financing	514		359
Stock-based compensation	3,068		2,435
Revaluation of put option and PIPE warrant liabilities	-8,796		13,612
Changes in operating assets and liabilities:	'		'
Prepaid expenses and other assets	-226		1,012
Restricted cash	'		-45
Accounts payable	528		-987
Accrued liabilities	-1,744		-1,615
Deferred revenue	9		'
Deferred rent	-9		-84
Net cash used in operating activities	-25,535		-25,935
Cash flows from investing activities:	'		'
Purchase of property and equipment	-4,756		-1,366
Purchase of investments	-14,884		-25,704
Proceeds from maturity of investments	14,629		22,232
Net cash used in investing activities	-5,011		-4,838
Cash flows from financing activities:	'		'
Proceeds from issuance of common stock in equity offerings, net of offerings costs	'		47,944
Proceeds from issuance of long-term debt	10,000		'
Payment of long-term debt	'		-5,789
Net proceeds from issuance of common stock through equity plans and exercise of warrants	2,386		1,481
Net cash provided by financing activities	12,386		43,636
Net (decrease) increase in cash and cash equivalents	-18,160		12,863
Cash and cash equivalents-Beginning of period	88,401	[1]	47,932
Cash and cash equivalents-End of period	$70,241		$60,795
[1]	The condensed balance sheet as of December 31, 2013 has been derived from the audited financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Organization and Summary of Significant Accounting Policies	'
	1. Organization and Summary of Significant Accounting Policies
	The Company
	AcelRx Pharmaceuticals, Inc., or the Company or AcelRx, was incorporated in Delaware on July 13, 2005 as SuRx, Inc., and in January 2006, the Company changed its name to AcelRx Pharmaceuticals, Inc. The Company’s operations are based in Redwood City, California.
	AcelRx is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain. AcelRx intends to commercialize its product candidates in the United States and license the development and commercialization rights to its product candidates for sale outside of the United States through strategic partnerships and collaborations. On July 25, 2014, the U.S. Food and Drug Administration, or FDA, issued a Complete Response Letter, or CRL, for the Company’s new drug application, or NDA, for Zalviso™ (sufentanil sublingual tablet system), formerly known as ARX-01. The proposed indication for Zalviso is for the management of moderate-to-severe acute pain in adult patients in the hospital setting. Zalviso consists of sufentanil tablets delivered by the Zalviso System, a needle-free, handheld, patient-administered, pain management system (together, “Zalviso”). In the third quarter of 2014, the Company held a meeting with the FDA to discuss the Zalviso CRL received in July. During the meeting the Company discussed the resubmission of the Zalviso NDA and the steps necessary for the resubmission. In advance of resubmitting the Zalviso NDA, the Company has agreed with the FDA to submit protocols for the bench testing and a Human Factors Study for their review and comment. In the interim, the Company continues the preparation necessary to initiate the bench testing and Human Factors study in the near term. Subject to the timing of the FDA review and comment on the protocols, the adequacy of such protocols, and the results generated from the bench testing and Human Factors Study, the Company is targeting resubmission of the Zalviso NDA in the first quarter of 2015. However, if the FDA review of the protocols takes longer than expected, the timing of the filing of the NDA could be later than the first quarter of 2015.
	In addition, in December 2013, the Company entered into a collaboration agreement with Grünenthal, a European-based pharmaceutical company, for the commercialization of Zalviso in Europe and Australia. The Marketing Authorization Application, or MAA, for Zalviso was filed by Grünenthal under the centralized procedure in the European Union, or EU, in July 2014.
	The Company has incurred recurring operating losses and negative cash flows from operating activities since inception and expects to continue to incur negative cash flows in the future as it prepares for the commercial launch of Zalviso and continues its research and development activities. In previous years, prior to the commercial collaboration of Zalviso with Grünenthal, AcelRx was considered a development stage company.
	The Company has one business activity, which is the development and commercialization of product candidates for the treatment of pain, and a single reporting and operating unit structure.
	Basis of Presentation
	The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and the rules and regulations of the U.S. Securities and Exchange Commission, or SEC. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included.
	Operating results for the three and nine months ended September 30, 2014, are not necessarily indicative of the results that may be expected for the year ending December 31, 2014. The condensed balance sheet as of December 31, 2013, was derived from the Company’s audited financial statements as of December 31, 2013, included in the Company’s Annual Report on Form 10-K filed with the SEC. These financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2013, which includes a broader discussion of the Company’s business and the risks inherent therein.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying notes. Management evaluates its estimates on an ongoing basis including critical accounting policies. Estimates are based on historical experience and on various other market-specific and other relevant assumptions that the Company believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.
	Recently Issued Accounting Standards
	In August 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. ASU 2014-15 will explicitly require management to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosure in certain circumstances. The new standard will be effective for AcelRx beginning in fiscal 2017. Earlier adoption is permitted. The Company is currently evaluating the potential impact of the adoption of ASU 2014-15.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, issued as a new Topic, Accounting Standards Codification (ASC) Topic 606. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle of the guidance is that a Company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU is effective for AcelRx beginning in fiscal 2017 and can be adopted by the Company either retrospectively or as a cumulative-effect adjustment as of the date of adoption. The Company is currently evaluating the effect that adopting this new accounting guidance will have on its results of operations, cash flows and financial position.

Investments_and_Fair_Value_Mea

Investments and Fair Value Measurement	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Investments and Fair Value Measurement	'
	2. Investments and Fair Value Measurement
	Investments
	The Company classifies its marketable securities as available-for-sale and records its investments at fair value. Available-for-sale securities are carried at estimated fair value based on quoted market prices or observable market inputs of almost identical assets, with the unrealized holding gains and losses included in accumulated other comprehensive income. Marketable securities which have maturities beyond one year as of the end of the reporting period are classified as non-current.
	The table below summarizes the Company’s cash, cash equivalents and investments (in thousands):
		As of September 30, 2014
		Amortized Cost			Gross Unrealized			Gross Unrealized		Fair
					Gains			Losses		Value
	Cash and cash equivalents:
	Cash	$	70,238		$	—		$	—	$	70,238
	Money market funds		3			—			—		3
	Total cash and cash equivalents		70,241			—			—		70,241
	Marketable securities:
	U.S. government agency securities		15,328			1			—	$	15,329
	Total marketable securities		15,328			1			—	$	15,329
	Total cash, cash equivalents and investments	$	85,569		$	1		$	—	$	85,570
		As of December 31, 2013
		Amortized Cost			Gross Unrealized			Gross Unrealized		Fair
					Gains			Losses		Value
	Cash and cash equivalents:
	Cash	$	88,390		$	—		$	—	$	88,390
	Money market funds		11			—			—		11
	Total cash and cash equivalents		88,401			—			—	$	88,401
	Marketable securities:
	U.S. government agency securities		15,261			1			—		15,262
	Total marketable securities		15,261			1			—	$	15,262
	Total cash, cash equivalents and investments	$	103,662		$	1		$	—	$	103,663
	As of September 30, 2014 and December 31, 2013, none of the available-for-sale securities held by the Company had material unrealized losses. There were no other-than-temporary impairments for these securities at September 30, 2014 or December 31, 2013. No gross realized gains or losses were recognized on the available-for-sale securities and, accordingly, there were no amounts reclassified out of accumulated other comprehensive income to earnings during the three and nine months ended September 30, 2014 and 2013.
	As of September 30, 2014 and December 31, 2013, the contractual maturity of all investments held was less than one year.
	Fair Value Measurement
	The Company’s financial instruments consist of Level I and Level II assets and Level III liabilities. Level I securities include highly liquid money market funds and are valued based on quoted market prices. For Level II instruments, the Company estimates fair value by utilizing third party pricing services in developing fair value measurements where fair value is based on valuation methodologies such as models using observable market inputs, including benchmark yields, reported trades, broker/dealer quotes, bids, offers and other reference data. Such Level II instruments typically include U.S. treasury and U.S. government agency obligations. As of September 30, 2014 and December 31, 2013, the Company held, in addition to Level I and Level II assets, a contingent put option liability associated with the Company’s Amended and Restated Loan and Security Agreement, or the Amended Loan Agreement, with Hercules Technology II, L.P. and Hercules Technology Growth Capital, Inc., collectively referred to as Hercules, which amends and restates the loan and security agreement with Hercules dated as of June 29, 2011, or the Original Loan Agreement, and which was classified as a Level III liability. See Note 5 “Long-Term Debt,” for further description. The Company’s estimate of fair value of the contingent put option liability was determined by using a risk-neutral valuation model, wherein the fair value of the underlying debt facility is estimated both with and without the presence of the default provisions, holding all other assumptions constant. The resulting difference between the two estimated fair values is the estimated fair value of the default provisions, or the contingent put option. Changes to the estimated fair value of these liabilities are recorded in interest income and other income (expense), net in the condensed statements of comprehensive loss. The fair value of the underlying debt facility is estimated by calculating the expected cash flows in consideration of an estimated probability of default and expected recovery rate in default, and discounting such cash flows back to the reporting date using a risk-free rate. As of September 30, 2014 and December 31, 2013, the Company also held a Level III liability associated with warrants, or PIPE warrants, issued in connection with the Company’s private placement equity offering, completed in June 2012. The PIPE warrants are considered a liability and are valued using the Black-Scholes option-pricing model, the inputs for which include exercise price of the PIPE warrants, market price of the underlying common shares, expected term, volatility based on a group of the Company’s peers and the risk-free rate corresponding to the expected term of the PIPE warrants. Changes to any of the inputs can have a significant impact to the estimated fair value of the PIPE warrants.
	The following table sets forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy (in thousands):
		As of September 30, 2014
		Fair Value			Level I			Level II		Level III
	Assets
	Money market funds	$	3		$	3		$	—	$	—
	U.S. government agency obligations		15,329			—			15,329		—
	Total assets measured at fair value	$	15,332		$	3		$	15,329	$	—
	Liabilities
	PIPE warrants	$	4,324			—			—	$	4,324
	Contingent put option liability		325			—			—		325
	Total liabilities measured at fair value	$	4,649		$	—		$	—	$	4,649
		As of December 31, 2013
		Fair Value			Level I			Level II		Level III
	Assets
	Money market funds	$	11		$	11		$	—	$	—
	U.S. government agency obligations		15,262			—			15,262		—
	Total assets measured at fair value	$	15,273		$	11		$	15,262	$	—
	Liabilities
	PIPE warrants	$	13,111			—			—	$	13,111
	Contingent put option liability	$	334			—			—	$	334
	Total liabilities measured at fair value	$	13,445		$	—		$	—	$	13,445
	The following table sets forth the assumptions used in the Black-Scholes option-pricing model to estimate the fair value of the PIPE warrants as of September 30, 2014:
	Market price	$	5.49
	Exercise price	$	3.4
	Risk-free interest rate		1.07	%
	Expected volatility		65	%
	Expected life (in years)		3.17
	Expected dividend yield		0	%
	The following table sets forth the assumptions used in the Black-Scholes option-pricing model to estimate the fair value of the PIPE warrants as of December 31, 2013:
	Market price	$	11.31
	Exercise price	$	3.4
	Risk-free interest rate		1.27	%
	Expected volatility		69	%
Expected life (in years)		3.92
Expected dividend yield		0	%
The following tables set forth a summary of the changes in the fair value of the Company’s Level III financial liabilities for the three and nine months ended September 30, 2014 and September 30, 2013 (in thousands):
	Three Months			Nine Months
	Ended			Ended
	September 30,			September 30,
	2014			2014
Fair value—beginning of period	$	11,726		$	13,445
Change in fair value of PIPE warrants		(6,964	)		(8,787	)
Change in fair value of contingent put option associated with Amended Loan Agreement with Hercules		(113	)		(9	)
Fair value—end of period	$	4,649		$	4,649
	Three Months			Nine Months
	Ended			Ended
	September 30,			September 30,
	2013			2013
Fair value—beginning of period	$	17,889		$	7,500
Change in fair value of PIPE warrants		(5,459	)		4,973
Change in fair value of contingent put option associated with Original Loan Agreement with Hercules		(7	)		(50	)
Fair value—end of period	$	12,423		$	12,423

Research_Grant_Agreement

Research Grant Agreement	9 Months Ended
	Sep. 30, 2014
Research and Development [Abstract]	'
Research Grant Agreement	'
	3. Research Grant Agreement
	In May 2011, AcelRx received a grant from the US Army Medical Research and Materiel Command, or USAMRMC, in which the USAMRMC granted $5.6 million to the Company in order to support the development of a new product candidate, ARX-04, a sufentanil tablet for the treatment of moderate-to-severe acute pain. Under the terms of the grant, the USAMRMC reimbursed the Company for development, manufacturing and clinical costs necessary to prepare for and complete the planned Phase 2 dose-finding trial in a study of acute moderate-to-severe pain, and to prepare to enter Phase 3 development. The grant gives the USAMRMC the option to extend the term of the grant and provide additional funding for the research. As of December 31, 2013, the full amount of the grant, $5.6 million, had been received and recognized as revenue.
	Revenue is recognized based on expenses incurred by AcelRx in conducting research and development activities set forth in the agreement. Revenue attributable to the research and development performed under the USAMRMC grant was $548,000 and $1.9 million for the three and nine months ended September 30, 2013, respectively. There was no such revenue recognized for the three and nine months ended September 30, 2014.

Collaboration_Agreement

Collaboration Agreement	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Collaboration Agreement	'
	4. Collaboration Agreement
	On December 16, 2013, AcelRx and Grünenthal GmbH, or Grünenthal, entered into a Collaboration and License Agreement (the “License Agreement”) and related Manufacture and Supply Agreement (the “Manufacturing Agreement” and together with the License Agreement, the “Grünenthal Agreements”). The License Agreement grants Grünenthal rights to commercialize Zalviso in the EU, Switzerland, Liechtenstein, Iceland, Norway and Australia, for pain treatment within or dispensed by hospitals, hospices, nursing homes and other medically-supervised settings. Under the Supply Agreement, the Company will exclusively manufacture and supply Zalviso to Grünenthal for sale in their territories.
	License Agreement
	Under the terms of the License Agreement, Grünenthal has the exclusive right to commercialize Zalviso in their territories. The Company retains control of clinical development, and together with Grünenthal will be responsible for certain development activities. The Company will not receive separate payment for such development activities. Grünenthal is responsible for marketing approval applications and other regulatory filings relating to the sufentanil drug cartridge for Zalviso, while the Company is responsible for the CE Mark and other regulatory filings relating to the device portions.
	The Company received an upfront non-refundable cash payment of $30.0 million in December 2013, and a milestone payment of $5.0 million related to the MAA submission in the third quarter of 2014. The Company is eligible to receive an additional $15.0 million milestone payment upon the approval of the MAA, if approved. If the MAA is approved, the Company is eligible to receive approximately $200.0 million in additional milestone payments, based upon successful regulatory and product development efforts ($28.5 million) and net sales target achievements ($171.5 million). Grünenthal will also make tiered royalty and supply and trademark fee payments in the mid-teens up to the mid-twenties percent range on net sales of Zalviso.
	Unless earlier terminated, the License Agreement continues in effect until the expiration of the obligation of Grünenthal to make royalty and supply and trademark fee payments, which supply and trademark fee continues for so long as the Company continues to supply Zalviso to Grünenthal. The License Agreement is subject to earlier termination in the event the parties mutually agree, by a party in the event of an uncured material breach by the other party, upon the bankruptcy or insolvency of either party, or by Grünenthal for convenience.
	Manufacturing Agreement
	Under the terms of the Manufacturing Agreement, the Company will manufacture and supply Zalviso exclusively for Grünenthal. The Company will supply Zalviso at the Company’s fully burdened manufacturing cost (as defined in the Manufacturing Agreement). The Manufacturing Agreement requires the Company to use commercially reasonable efforts to enter stand-by contracts with third party contract manufacturers to ensure continual supply of Zalviso and under certain conditions permits Grünenthal to use a third party back-up manufacturer to manufacture Zalviso for commercial sale in their territories.
	Unless earlier terminated, the Manufacturing Agreement continues in effect until the later of the expiration of the obligation of Grünenthal to make royalty and supply and trademark fee payments or the end of any transition period for manufacturing obligations due to the expiration or termination of the License Agreement. The Manufacturing Agreement is subject to earlier termination in connection with certain termination events in the License Agreement, in the event the parties mutually agree, by a party in the event of an uncured material breach by the other party or upon the bankruptcy or insolvency of either party.
	The Company identified the following four significant non-contingent performance deliverables under the agreements: 1) intellectual property (license), 2) the obligation to provide research and development services, 3) the significant and incremental discount on the manufacturing of Zalviso for commercial purposes, and 4) the obligation to participate on the joint steering committee. The Company developed best estimates of selling prices for each deliverable in order to allocate the non-contingent arrangement consideration to the four units of accounting.
	The Company’s management determined the best estimate of selling price for the license based on Grünenthal’s estimated future cash flows arising from the arrangement. Embedded in the estimate were significant assumptions regarding regulatory expenses, revenue, including potential customer market for the product and product price, costs to manufacture the product and the discount rate. The Company’s management determined the best estimate of selling price of the research and development services and committee participation based on the nature and timing of the services to be performed and in consideration of personnel and other costs incurred in the delivery of the services. For the discount on manufacturing services, the Company’s management estimated the selling price based on the market level of contract manufacturing margin it could have received if it were engaged to supply products to a customer in a separate transaction.
	The Agreements entitle the Company to receive additional payments upon the achievement of certain development and sales milestones. Based on ASC Topic 605-28, Revenue Recognition — Milestone Method, the Company evaluates contingent milestones at the inception of the agreement, and recognizes consideration that is contingent upon the achievement of a milestone in its entirety as revenue in the period in which the milestone is achieved only if the milestone is considered substantive in its entirety. Milestones are events which have the following characteristics: (i) they can be achieved based in whole or in part on either the Company’s performance or on the occurrence of a specific outcome resulting from the Company’s performance, (ii) there was substantive uncertainty at the date the agreement was entered into that the event would be achieved and, (iii) they would result in additional payments due to the Company. A milestone is considered substantive if the following criteria are met: (i) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item (s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (ii) the consideration relates solely to past performance and, (iii) the consideration is reasonable relative to all of the other deliverables and payment terms, including other potential milestone consideration, within the arrangement.
	The substantive milestone payments will be recognized as revenue in their entirety upon the achievement of each substantive milestone. Based on the criteria noted above, the identified substantive milestones in the agreement pertain to post-approval product enhancements, expanded market opportunities and manufacturing efficiencies for Zalviso. Each of these potential achievements is based primarily on the Company’s performance and involves substantive uncertainty as achievement of these milestones requires future research, development and regulatory activities, which are inherently uncertain in nature. The Company determined that the consideration for each milestone was commensurate with the Company’s performance to achieve the milestone, including future research, development, manufacturing and regulatory activities and that the consideration is reasonable relative to all of the other deliverables and payments within the arrangement. Aggregate potential payments for these milestones total $28.5 million.
	In addition to substantive milestones, two milestones associated with the Agreements were deemed not to be substantive. These milestones pertain to regulatory developments for Zalviso in Europe, which the Company’s management deemed to be not substantive due to the level of performance associated with future achievement of these milestones. Aggregate potential payments for these milestones total $20.0 million. When achieved, the value of these milestones will be allocated to the four separate units of accounting based on estimated selling prices and recognized as revenue in the period of achievement to the extent the services underlying the separate units of accounting have been performed. In July 2014, Grünenthal submitted a Marketing Authorization Application, or MAA, to the European Medicines Agency, or EMA, for Zalviso for the management of moderate-to-severe acute pain in adult patients in a medically supervised environment. Under the terms of the License Agreement with Grünenthal, the Company received a cash payment of $5.0 million for the MAA submission in the third quarter of 2014. The Company is eligible to receive an additional $15.0 million milestone payment upon the approval of the MAA.
	The Agreements also include milestone payments related to specified net sales targets, totaling $171.5 million. The sales-based milestones do not meet the definition of a milestone under ASU 2010-17 because the achievement of these milestones is solely dependent on counter-party performance and not on any performance obligations of the Company.
	The Company allocated the $30.0 million upfront fee across the four deliverables based on estimated selling prices and for the quarter ended December 31, 2013, recognized $27.4 million attributable to the license. The remaining $2.6 million was recorded as deferred revenue at December 31, 2013, to be recognized in future periods to the extent services are performed related to the other non-contingent performance deliverables under the agreements.
	The Company recognized $4.8 million and $5.0 million, of previously deferred revenue related to research and development services under the collaboration agreement during the three and nine months ended September 30, 2014, respectively. As of September 30, 2014, the Company had a deferred revenue balance of $2.6 million. As mentioned above, the Company received a milestone payment of $5.0 million related to the MAA submission, of which $4.6 million was recognized during the three months ended September 30, 2014. There were no other milestone payments received or recognized under these Agreements during the three and nine months ended September 30, 2014.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	5. Long-Term Debt
	Hercules Loan and Security Agreements
	In June 2011, AcelRx entered into a Loan and Security Agreement, or the Original Loan Agreement, with Hercules Technology II, L.P. and Hercules Technology Growth Capital, Inc., collectively referred to as Hercules, under which AcelRx borrowed $20.0 million in two tranches of $10.0 million each, represented by secured convertible term promissory notes, or collectively, the Original Notes. The Company’s obligations associated with the agreement were secured by a security interest in substantially all of its assets, other than its intellectual property.
	The Company borrowed the first tranche of $10.0 million upon the closing of the transaction on June 29, 2011 and borrowed the second tranche of $10.0 million in December 2011. The interest rate for each tranche was 8.50%. In connection with the Original Loan Agreement, the Company issued Hercules seven-year warrants to purchase an aggregate of 274,508 shares of common stock at a price of $3.06 per share. See Note 6 “Warrants,” for further description.
	On December 16, 2013, AcelRx entered into an Amended and Restated Loan and Security Agreement, or the Amended Loan Agreement, with Hercules, under which the Company may borrow up to $40.0 million in three tranches. These loans are represented by secured convertible term promissory notes, or collectively, the Amended Notes. The Amended Loan Agreement amends and restates the Original Loan Agreement, as noted above. The Company borrowed the first tranche of $15.0 million upon closing of the transaction on December 16, 2013 and the second tranche of $10.0 million on June 16, 2014. The Company used approximately $8.6 million of the proceeds from the first tranche to repay its obligations under the Original Loan Agreement. The Company recorded the new debt at an estimated fair value of $24.9 million and $14.3 million as of September 30, 2014 and December 31, 2013, respectively.
	On September 24, 2014, the Company entered into an amendment, or the Amendment, to the Amended Loan Agreement with Hercules. The Amendment extends the time period under which the Company can draw down the third tranche, of up to $15.0 million, from March 15, 2015 to August 1, 2015, subject to the Company obtaining approval for Zalviso from the U.S. Food and Drug Administration.
	The interest rate for each tranche will be calculated at a rate equal to the greater of either (i) 9.10% plus the prime rate as reported from time to time in The Wall Street Journal minus 5.25%, and (ii) 9.10%. Payments under the Amended Loan Agreement are interest only until April 1, 2015 (which will be extended until January 1, 2016 if the Company achieves the Milestone on or before April 1, 2015) followed by equal monthly payments of principal and interest through the scheduled maturity date on October 1, 2017 (which would be extended until January 1, 2018 if the Company achieves the Milestone on or prior to April 1, 2015), or the Loan Maturity Date. In addition, a final payment equal to $1.7 million will be due on the Loan Maturity Date, or such earlier date specified in the Amended Loan Agreement. The Company’s obligations under the Amended Loan Agreement are secured by a security interest in substantially all of its assets, other than its intellectual property.
	If the Company prepays the Amended Loan Agreement prior to maturity, it will pay Hercules a prepayment charge, based on a percentage of the then outstanding principal balance, equal to 3% if the prepayment occurs prior to December 16, 2014, 2% if the prepayment occurs after December 16, 2014, but prior to December 16, 2015, or 1% if the prepayment occurs after December 16, 2015.
	Subject to certain conditions and limitations set forth in the Amended Loan Agreement, the Company has the right to convert up to $5.0 million of scheduled principal installments under the Notes into freely tradeable shares of the Company’s common stock, or Common Stock. The number of shares of Common Stock that would be issued upon conversion of the Amended Notes would be equal to the number determined by dividing (x) the product of (A) the principal amount to be paid in shares of Common Stock and (B) 103%, by (y) $9.30 (subject to certain proportional adjustments as provided for in the Amended Loan Agreement).
	The Amended Loan Agreement includes customary affirmative and restrictive covenants, but does not include any financial maintenance covenants, and also includes standard events of default, including payment defaults, breaches of covenants following any applicable cure period, a material impairment in the perfection or priority of Hercules’ security interest or in the value of the collateral, and events relating to bankruptcy or insolvency. Upon the occurrence of an event of default, a default interest rate of an additional 5% may be applied to the outstanding loan balances, and Hercules may declare all outstanding obligations immediately due and payable and take such other actions as set forth in the Amended Loan Agreement.
	In connection with the Amended Loan Agreement, the Company issued a warrant to each Lender which, collectively, are exercisable for an aggregate of 176,730 shares of Common Stock and each carry an exercise price of $6.79. See Note 6 “Warrants,” for further description.
	Upon an event of default, including a change of control, Hercules has the option to accelerate repayment of the Amended Loan Agreement, including payment of any applicable prepayment charges, which range from 1%-3% of the outstanding loan balance and accrued interest, as well as a final payment fee of $1.7 million. This option is considered a contingent put option liability, as the holder of the loan may exercise the option in the event of default, and is considered an embedded derivative, which must be valued and separately accounted for in the Company’s financial statements. As the amendment of the loan agreement was considered an extinguishment, the contingent put option liability associated with the Original Loan Agreement, which had an estimated fair value of $32,000 at the time of the amendment, was written off as a part of the loss on extinguishment, and a new contingent put option liability was established. As of September 30, 2014 and December 31, 2013, the estimated fair value of the contingent put option liability was $325,000 and $334,000, respectively, which was determined by using a risk-neutral valuation model, wherein the fair value of the underlying debt facility is estimated both with and without the presence of the default provisions, holding all other assumptions constant. The resulting difference between the two estimated fair values is the estimated fair value of the default provisions, or the contingent put option. The fair value of the underlying debt facility is estimated by calculating the expected cash flows in consideration of an estimated probability of default and expected recovery rate in default, and discounting such cash flows back to the reporting date using a risk-free rate. The contingent put option liability was recorded as a debt discount to the loan and consequently a reduction to the carrying value of the loan. The contingent put option liability is revalued at the end of each reporting period and any change in the fair value is recognized in interest income and other income (expense), net in the condensed statements of comprehensive loss.
	As of September 30, 2014 and December 31, 2013, the Company had outstanding borrowings under the Amended Loan Agreement of $25.0 million and $15.0 million, respectively. Interest expense related to the Amended Loan Agreement was $813,000 and $1.8 million for the three and nine months ended September 30, 2014, respectively, $231,000 and $504,000 of which represented amortization of the debt discount for the three and nine months ended September 30, 2014, respectively. Interest expense related to the Original Loan Agreement was $348,000 and $1.2 million for the three and nine months ended September 30, 2013, respectively, $85,000 and $290,000 of which represented amortization of the debt discount for the three and nine months ended September 30, 2013, respectively.

Warrants

Warrants	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Warrants	'
	6. Warrants
	Series A Warrants
	In March 2007, the Company entered into an equipment financing agreement in which the Company issued immediately exercisable and fully vested warrants to purchase 2,500 shares of its Series A convertible preferred stock, or the Series A warrants, with an exercise price of $10.00 per share. The fair value of the Series A warrants on the date of issuance was $1,000, as determined using the Black-Scholes option-pricing model. This fair value was recorded as a convertible preferred stock warrant liability and as a deferred financing cost in other assets. The fair value was remeasured at the end of each reporting period. In connection with the IPO, the Series A warrants were automatically converted into warrants to purchase 3,425 shares of common stock. As a result of the conversion, these common stock warrants were no longer recorded as liabilities and were, therefore, no longer remeasured as of the end of each reporting period.
	As of September 30, 2014, warrants to purchase 3,425 shares of common stock had not been exercised and were still outstanding. These warrants expire in March 2017.
	Pinnacle Warrants
	In September 2008, the Company entered into a $12.0 million loan and security agreement with Pinnacle Ventures. In connection with this loan and security agreement, the Company issued immediately exercisable and fully vested warrants, or the Series B warrants, to purchase 56,250 shares of Series B convertible preferred stock with an exercise price of $16.00 per share which were ultimately converted into warrants to purchase 228,264 shares of common stock with an exercise price of $3.94 per share in connection with the Company’s initial public offering in 2011.
	In February 2013, warrants to purchase 228,264 shares were net exercised, for 58,580 shares of common stock. As of September 30, 2014, no warrants to purchase shares of common stock issued to Pinnacle were outstanding.
	Hercules Warrants
	In connection with the Amended Loan Agreement, executed in December 2013, the Company issued warrants to Hercules which are exercisable for an aggregate of 176,730 shares of Common Stock and each carry an exercise price of $6.79 (the “Warrants”). Each Warrant may be exercised on a cashless basis. The Warrants are exercisable for a term beginning on the date of issuance and ending on the earlier to occur of five years from the date of issuance or the consummation of certain acquisitions of the Company as set forth in the Warrants. The number of shares for which the Warrants are exercisable and the associated exercise price are subject to certain proportional adjustments as set forth in the Warrants. The Company estimated the fair value of these warrants as of the issuance date to be $1.1 million, which was recorded as equity. The fair value of the warrants was calculated using the Black-Scholes option-valuation model, and was based on the strike price of $6.79, the stock price at issuance of $9.67, the five-year contractual term of the warrants, a risk-free interest rate of 1.55%, expected volatility of 71% and 0% expected dividend yield.
	As of September 30, 2014, warrants to purchase 176,730 shares of common stock issued to Hercules had not been exercised and were still outstanding. These warrants expire in December 2018.
	In connection with the Original Loan Agreement with Hercules, executed in June 2011, the Company issued warrants to Hercules to purchase an aggregate of 274,508 shares of common stock at a price of $3.06 per share.
	During June and July 2013, warrants to purchase 274,508 shares were net exercised, for 183,404 shares of common stock.
	2012 Private Placement Warrants
	In connection with the Private Placement, completed in June 2012, the Company issued PIPE warrants to purchase up to 2,630,103 shares of common stock. The per share exercise price of the PIPE warrants was $3.40 which equals the closing consolidated bid price of the Company’s common stock on May 29, 2012, the effective date of the Purchase Agreement. The PIPE warrants issued in the Private Placement became exercisable six months after the issuance date, and expire on the five year anniversary of the initial exercisability date. Under the terms of the PIPE warrants, upon certain transactions, including a merger, tender offer, sale of all or substantially all of the assets of the Company or if a person or group shall become the owner of 50% of the Company’s issued and outstanding common stock, which is outside of the Company’s control, each PIPE warrant holder may elect to receive a cash payment in exchange for the warrant, in an amount determined by application of the Black-Scholes option-pricing model. Accordingly, the PIPE warrants were recorded as a liability at fair value, as determined by the Black-Scholes option-pricing model, and then marked to fair value each reporting period, with changes in estimated fair value recorded through interest income and other income (expense), net in the condensed statements of comprehensive loss. The Black-Scholes assumptions used to value the PIPE warrants are disclosed in Note 2.
	Upon execution of the Purchase Agreement, the fair value of the PIPE warrants was estimated to be $5.8 million, which was recorded as a liability. As of September 30, 2014, the fair value of the PIPE warrants was estimated to be $4.3 million. As of December 31, 2013, the fair value of the PIPE warrants was estimated to be $13.1 million. The change in fair value for the three and nine months ended September 30, 2014, which was recorded as other income, was $6.4 million and $8.2 million, respectively. The change in fair value for the three and nine months ended September 30, 2013, recorded as other expense, was $2.4 million and $13.4 million, respectively.
	During the three and nine months ended September 30, 2014, PIPE warrants to purchase 135,000 shares were net exercised for 91,488 shares of common stock. As of September 30, 2014, PIPE warrants to purchase 1,359,514 shares of common stock issued in connection with the Private Placement had not been exercised and were outstanding. These warrants expire in November 2017.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	7. Stock-Based Compensation
	The Company recorded total stock-based compensation expense for stock options, stock awards and the 2011 Employee Stock Purchase Plan as follows (in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Expenses:
	Research and development	$	568	$	427	$	1,607	$	1,193
	General and administrative		631		449		1,461		1,242
	Total stock-based compensation expense	$	1,199	$	876	$	3,068	$	2,435
	As of September 30, 2014 there were 1,160,866 shares available for grant, 5,313,236 options outstanding and 0 restricted stock units outstanding under the Company’s 2011 Equity Incentive Plan.

Net_Loss_per_Share_of_Common_S

Net Loss per Share of Common Stock	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Net Loss per Share of Common Stock	'
	8. Net Loss per Share of Common Stock
	The Company’s basic net loss per share of common stock is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. The diluted net loss per share of common stock is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, options to purchase common stock and warrants to purchase common stock were considered to be common stock equivalents. In periods with a reported net loss, common stock equivalents are excluded from the calculation of diluted net loss per share of common stock if their effect is antidilutive.
	During the three and nine months ended September 30, 2014, the PIPE warrants had a dilutive impact to net loss per share due to a lower share price at September 30, 2014, compared to the closing share price on June 30, 2014 and December 31, 2013. The decrease in share price created a lower Black-Scholes value and lower liability for the PIPE warrants, which resulted in other income during the three and nine months ended September 30, 2014. The calculation of diluted net loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the PIPE warrants and the presumed exercise of such securities are dilutive to loss per share for the period, adjustments to net loss used in the calculation are required to remove the change in fair value of the PIPE warrants for the period. Likewise, adjustments to the denominator are required to reflect the related dilutive shares.
	The following table sets forth the computation of the Company’s basic and diluted net loss per share of common stock during the three and nine months ended September 30, 2014 and 2013 (in thousands, except for share and per share amounts):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in thousands, except share and per share amounts)
	Numerator
	Net income (loss) used to compute net income (loss) per share:
	Basic	$	671		$	(10,986	)	$	(19,535	)	$	(41,195	)
	Adjustments for change in fair value of warrant liability		(6,418	)		—			(8,241	)		—
	Diluted	$	(5,747	)	$	(10,986	)	$	(27,776	)	$	(41,195	)
	Denominator
	Weighted average shares outstanding used to compute net loss per share:
	Basic		43,469,354			41,462,425			43,332,013			38,635,370
	Dilutive effect of warrants		794,138			—			955,946			—
	Diluted		44,263,492			41,462,425			44,287,959			38,635,370
	Net income (loss) per share—basic	$	0.02		$	(0.26	)	$	(0.45	)	$	(1.07	)
	Net loss per share—diluted	$	(0.13	)	$	(0.26	)	$	(0.63	)	$	(1.07	)
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share of common stock for the periods presented because including them would have been antidilutive:
		September 30,
		2014			2013
	Stock options to purchase common stock		5,313,236			4,923,633
	Restricted stock units		—			65,765
	Common stock warrants		180,155			1,497,939

Manufacturing_Agreements

Manufacturing Agreements	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Manufacturing Agreements	'
	9. Manufacturing Agreements
	Patheon
	In January 2013, the Company and Patheon Pharmaceuticals Inc., or Patheon, entered into a Manufacturing Services Agreement, or the Services Agreement, and a related Amended and Restated Capital Expenditure and Equipment Agreement, or the Capital Agreement, relating to the manufacture of sufentanil tablets, or the Product, for use with the Company’s Zalviso drug product.
	Under the terms of the Services Agreement, the Company has agreed to purchase, subject to Patheon’s continued material compliance with the terms of the Services Agreement, all of its Product requirements for the United States, Canada and Mexico from Patheon during the Initial Term of the Services Agreement (as defined below), and at least eighty percent (80%) of its Product requirements for such territories after the Initial Term.
	The term of the Services Agreement extends until December 31, 2017, or the Initial Term, and will automatically renew thereafter for periods of two years, unless terminated by either party upon eighteen months’ prior written notice; provided, however, that the Services Agreement may not be terminated without cause prior to the end of the Initial Term.
	The Company also entered into a Capital Expenditure and Equipment Agreement, or the Capital Agreement. Under the terms of the Capital Agreement, as amended in January 2014, the Company has made and continues to make certain modifications to Patheon’s Cincinnati facility. Property and equipment, net in the condensed balance sheet at September 30, 2014, includes $3.6 million related to certain modifications the Company is making at Patheon’s Cincinnati facility under the terms of the Capital Agreement.
	Expenditures associated with the aforementioned agreements are primarily driven by the potential commercial requirements and demand for the Company’s products, none of which have been approved for commercialization; accordingly, the amounts and timing of such future expenditures cannot be determined at this time.
	Grünenthal
	On December 16, 2013, AcelRx and Grünenthal entered into a Collaboration and License Agreement (the “License Agreement”) and related Manufacture and Supply Agreement (the “Manufacturing Agreement” and together with the License Agreement, the “Grünenthal Agreements”). The License Agreement grants Grünenthal rights to commercialize Zalviso in the EU, Switzerland, Liechtenstein, Iceland, Norway and Australia, for pain treatment within or dispensed by hospitals hospices, nursing homes and other medically-supervised settings.
	Under the terms of the Manufacturing Agreement, the Company will manufacture and supply Zalviso exclusively for Grünenthal. The Company will supply Zalviso at the Company’s fully burdened manufacturing cost (as defined in the Manufacturing Agreement). The Manufacturing Agreement requires the Company to use commercially reasonable efforts to enter stand-by contracts with third party contract manufacturers to ensure a continual supply of Zalviso and under certain conditions permits Grünenthal to use a third party back-up manufacturer to manufacture Zalviso for commercial sale in their territories.
	Unless earlier terminated, the Manufacturing Agreement continues in effect until the later of the expiration of the obligation of Grünenthal to make royalty and supply and trademark fee payments or the end of any transition period for manufacturing obligations due to the expiration or termination of the License Agreement. The Manufacturing Agreement is subject to earlier termination in connection with certain termination events in the License Agreement, in the event the parties mutually agree, by a party in the event of an uncured material breach by the other party or upon the bankruptcy or insolvency of either party.
	Under the Supply Agreement, the Company will exclusively manufacture and supply Zalviso to Grünenthal for commercial sale in their territories.
	Expenditures associated with the aforementioned agreements are primarily driven by the potential commercial requirements and demand for the Company’s products, none of which have been approved for commercialization; accordingly, the amounts and timing of such future expenditures cannot be determined at this time.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	10. Commitments and Contingencies
	Operating Leases
	In May 2014, the Company entered into an amendment, or the Lease Amendment, to that certain lease dated December 21, 2011, with Metropolitan Life Insurance Company, or the Existing Lease, for 13,787 square feet of space located at 301 Galveston Drive, Redwood City, California, or the Current Premises. Pursuant to the Lease Amendment, the term of the Existing Lease has been extended for a period of twenty (20) months and twenty-two (22) days and expiring January 31, 2018, or the Expiration Date, unless sooner terminated pursuant to the terms of the Existing Lease. In addition, the Lease Amendment included a new lease on an additional 12,106 square feet of office space, or the Expansion Space, which is adjacent to the current premises. The new lease for the Expansion Space has a term of 42 months commencing on August 1, 2014, and expiring on the Expiration Date. The Company has an option to extend the term of the Lease Amendment for an additional five years, which would commence upon the Expiration Date, at a market rate determined according to the Existing Lease.
	Base rent payable under the Lease Amendment during the Extended Term for the Current Premises will be as follows:
	Period from/to	Monthly Base
		Rent
	May 9, 2016 to May 8, 2017	$	35,961.55
	May 9, 2017 to January 31, 2018		37,040.40
	Base rent payable under the Lease Amendment for the Expansion Space, commencing August 1, 2014, will be as follows:
	Months of Lease Term	Monthly Base
		Rent
	12-Jan	$	23,001.40
	13-24		23,691.44
	25-36		24,402.18
	37-42		25,134.25
	In addition, the Company will pay the Landlord specified percentages of certain operating expenses and taxes related to the leased facility incurred by the Landlord.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	11. Subsequent Events
	On October 1, 2014, a securities class action complaint was filed in the U.S. District Court for the Northern District of California against the Company and certain of its current and former officers. The complaint alleges that between December 2, 2013 and September 25, 2014, the Company and certain of its officers violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 in connection with statements related to the Company’s lead drug candidate, Zalviso. Specifically, the complaint alleges that the Company’s statements were false and misleading because the Company failed to disclose that the Instructions for Use for Zalviso were designed improperly and the Company did not submit to the FDA sufficient data to support the shelf life of the product. The complaint seeks unspecified damages, interest, attorneys’ fees, and other costs. The Company believes that it has meritorious defenses and intends to defend against this lawsuit vigorously.
	From time to time, the Company may be involved in additional legal proceedings arising in the ordinary course of business.

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
The Company	'
	The Company
	AcelRx Pharmaceuticals, Inc., or the Company or AcelRx, was incorporated in Delaware on July 13, 2005 as SuRx, Inc., and in January 2006, the Company changed its name to AcelRx Pharmaceuticals, Inc. The Company’s operations are based in Redwood City, California.
	AcelRx is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain. AcelRx intends to commercialize its product candidates in the United States and license the development and commercialization rights to its product candidates for sale outside of the United States through strategic partnerships and collaborations. On July 25, 2014, the U.S. Food and Drug Administration, or FDA, issued a Complete Response Letter, or CRL, for the Company’s new drug application, or NDA, for Zalviso™ (sufentanil sublingual tablet system), formerly known as ARX-01. The proposed indication for Zalviso is for the management of moderate-to-severe acute pain in adult patients in the hospital setting. Zalviso consists of sufentanil tablets delivered by the Zalviso System, a needle-free, handheld, patient-administered, pain management system (together, “Zalviso”). In the third quarter of 2014, the Company held a meeting with the FDA to discuss the Zalviso CRL received in July. During the meeting the Company discussed the resubmission of the Zalviso NDA and the steps necessary for the resubmission. In advance of resubmitting the Zalviso NDA, the Company has agreed with the FDA to submit protocols for the bench testing and a Human Factors Study for their review and comment. In the interim, the Company continues the preparation necessary to initiate the bench testing and Human Factors study in the near term. Subject to the timing of the FDA review and comment on the protocols, the adequacy of such protocols, and the results generated from the bench testing and Human Factors Study, the Company is targeting resubmission of the Zalviso NDA in the first quarter of 2015. However, if the FDA review of the protocols takes longer than expected, the timing of the filing of the NDA could be later than the first quarter of 2015.
	In addition, in December 2013, the Company entered into a collaboration agreement with Grünenthal, a European-based pharmaceutical company, for the commercialization of Zalviso in Europe and Australia. The Marketing Authorization Application, or MAA, for Zalviso was filed by Grünenthal under the centralized procedure in the European Union, or EU, in July 2014.
	The Company has incurred recurring operating losses and negative cash flows from operating activities since inception and expects to continue to incur negative cash flows in the future as it prepares for the commercial launch of Zalviso and continues its research and development activities. In previous years, prior to the commercial collaboration of Zalviso with Grünenthal, AcelRx was considered a development stage company.
	The Company has one business activity, which is the development and commercialization of product candidates for the treatment of pain, and a single reporting and operating unit structure.
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and the rules and regulations of the U.S. Securities and Exchange Commission, or SEC. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included.
	Operating results for the three and nine months ended September 30, 2014, are not necessarily indicative of the results that may be expected for the year ending December 31, 2014. The condensed balance sheet as of December 31, 2013, was derived from the Company’s audited financial statements as of December 31, 2013, included in the Company’s Annual Report on Form 10-K filed with the SEC. These financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2013, which includes a broader discussion of the Company’s business and the risks inherent therein.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying notes. Management evaluates its estimates on an ongoing basis including critical accounting policies. Estimates are based on historical experience and on various other market-specific and other relevant assumptions that the Company believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.
Recently Issued Accounting Standards	'
	Recently Issued Accounting Standards
	In August 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. ASU 2014-15 will explicitly require management to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosure in certain circumstances. The new standard will be effective for AcelRx beginning in fiscal 2017. Earlier adoption is permitted. The Company is currently evaluating the potential impact of the adoption of ASU 2014-15.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, issued as a new Topic, Accounting Standards Codification (ASC) Topic 606. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle of the guidance is that a Company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU is effective for AcelRx beginning in fiscal 2017 and can be adopted by the Company either retrospectively or as a cumulative-effect adjustment as of the date of adoption. The Company is currently evaluating the effect that adopting this new accounting guidance will have on its results of operations, cash flows and financial position.
Investments	'
	Investments
	The Company classifies its marketable securities as available-for-sale and records its investments at fair value. Available-for-sale securities are carried at estimated fair value based on quoted market prices or observable market inputs of almost identical assets, with the unrealized holding gains and losses included in accumulated other comprehensive income. Marketable securities which have maturities beyond one year as of the end of the reporting period are classified as non-current.
Fair Value Measurement	'
	Fair Value Measurement
	The Company’s financial instruments consist of Level I and Level II assets and Level III liabilities. Level I securities include highly liquid money market funds and are valued based on quoted market prices. For Level II instruments, the Company estimates fair value by utilizing third party pricing services in developing fair value measurements where fair value is based on valuation methodologies such as models using observable market inputs, including benchmark yields, reported trades, broker/dealer quotes, bids, offers and other reference data. Such Level II instruments typically include U.S. treasury and U.S. government agency obligations. As of September 30, 2014 and December 31, 2013, the Company held, in addition to Level I and Level II assets, a contingent put option liability associated with the Company’s Amended and Restated Loan and Security Agreement, or the Amended Loan Agreement, with Hercules Technology II, L.P. and Hercules Technology Growth Capital, Inc., collectively referred to as Hercules, which amends and restates the loan and security agreement with Hercules dated as of June 29, 2011, or the Original Loan Agreement, and which was classified as a Level III liability. See Note 5 “Long-Term Debt,” for further description. The Company’s estimate of fair value of the contingent put option liability was determined by using a risk-neutral valuation model, wherein the fair value of the underlying debt facility is estimated both with and without the presence of the default provisions, holding all other assumptions constant. The resulting difference between the two estimated fair values is the estimated fair value of the default provisions, or the contingent put option. Changes to the estimated fair value of these liabilities are recorded in interest income and other income (expense), net in the condensed statements of comprehensive loss. The fair value of the underlying debt facility is estimated by calculating the expected cash flows in consideration of an estimated probability of default and expected recovery rate in default, and discounting such cash flows back to the reporting date using a risk-free rate. As of September 30, 2014 and December 31, 2013, the Company also held a Level III liability associated with warrants, or PIPE warrants, issued in connection with the Company’s private placement equity offering, completed in June 2012. The PIPE warrants are considered a liability and are valued using the Black-Scholes option-pricing model, the inputs for which include exercise price of the PIPE warrants, market price of the underlying common shares, expected term, volatility based on a group of the Company’s peers and the risk-free rate corresponding to the expected term of the PIPE warrants. Changes to any of the inputs can have a significant impact to the estimated fair value of the PIPE warrants.
Manufacturing Agreement	'
	Manufacturing Agreement
	Under the terms of the Manufacturing Agreement, the Company will manufacture and supply Zalviso exclusively for Grünenthal. The Company will supply Zalviso at the Company’s fully burdened manufacturing cost (as defined in the Manufacturing Agreement). The Manufacturing Agreement requires the Company to use commercially reasonable efforts to enter stand-by contracts with third party contract manufacturers to ensure continual supply of Zalviso and under certain conditions permits Grünenthal to use a third party back-up manufacturer to manufacture Zalviso for commercial sale in their territories.
	Unless earlier terminated, the Manufacturing Agreement continues in effect until the later of the expiration of the obligation of Grünenthal to make royalty and supply and trademark fee payments or the end of any transition period for manufacturing obligations due to the expiration or termination of the License Agreement. The Manufacturing Agreement is subject to earlier termination in connection with certain termination events in the License Agreement, in the event the parties mutually agree, by a party in the event of an uncured material breach by the other party or upon the bankruptcy or insolvency of either party.
	The Company identified the following four significant non-contingent performance deliverables under the agreements: 1) intellectual property (license), 2) the obligation to provide research and development services, 3) the significant and incremental discount on the manufacturing of Zalviso for commercial purposes, and 4) the obligation to participate on the joint steering committee. The Company developed best estimates of selling prices for each deliverable in order to allocate the non-contingent arrangement consideration to the four units of accounting.
	The Company’s management determined the best estimate of selling price for the license based on Grünenthal’s estimated future cash flows arising from the arrangement. Embedded in the estimate were significant assumptions regarding regulatory expenses, revenue, including potential customer market for the product and product price, costs to manufacture the product and the discount rate. The Company’s management determined the best estimate of selling price of the research and development services and committee participation based on the nature and timing of the services to be performed and in consideration of personnel and other costs incurred in the delivery of the services. For the discount on manufacturing services, the Company’s management estimated the selling price based on the market level of contract manufacturing margin it could have received if it were engaged to supply products to a customer in a separate transaction.
	The Agreements entitle the Company to receive additional payments upon the achievement of certain development and sales milestones. Based on ASC Topic 605-28, Revenue Recognition — Milestone Method, the Company evaluates contingent milestones at the inception of the agreement, and recognizes consideration that is contingent upon the achievement of a milestone in its entirety as revenue in the period in which the milestone is achieved only if the milestone is considered substantive in its entirety. Milestones are events which have the following characteristics: (i) they can be achieved based in whole or in part on either the Company’s performance or on the occurrence of a specific outcome resulting from the Company’s performance, (ii) there was substantive uncertainty at the date the agreement was entered into that the event would be achieved and, (iii) they would result in additional payments due to the Company. A milestone is considered substantive if the following criteria are met: (i) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item (s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (ii) the consideration relates solely to past performance and, (iii) the consideration is reasonable relative to all of the other deliverables and payment terms, including other potential milestone consideration, within the arrangement.
	The substantive milestone payments will be recognized as revenue in their entirety upon the achievement of each substantive milestone. Based on the criteria noted above, the identified substantive milestones in the agreement pertain to post-approval product enhancements, expanded market opportunities and manufacturing efficiencies for Zalviso. Each of these potential achievements is based primarily on the Company’s performance and involves substantive uncertainty as achievement of these milestones requires future research, development and regulatory activities, which are inherently uncertain in nature. The Company determined that the consideration for each milestone was commensurate with the Company’s performance to achieve the milestone, including future research, development, manufacturing and regulatory activities and that the consideration is reasonable relative to all of the other deliverables and payments within the arrangement. Aggregate potential payments for these milestones total $28.5 million.
	In addition to substantive milestones, two milestones associated with the Agreements were deemed not to be substantive. These milestones pertain to regulatory developments for Zalviso in Europe, which the Company’s management deemed to be not substantive due to the level of performance associated with future achievement of these milestones. Aggregate potential payments for these milestones total $20.0 million. When achieved, the value of these milestones will be allocated to the four separate units of accounting based on estimated selling prices and recognized as revenue in the period of achievement to the extent the services underlying the separate units of accounting have been performed. In July 2014, Grünenthal submitted a Marketing Authorization Application, or MAA, to the European Medicines Agency, or EMA, for Zalviso for the management of moderate-to-severe acute pain in adult patients in a medically supervised environment. Under the terms of the License Agreement with Grünenthal, the Company received a cash payment of $5.0 million for the MAA submission in the third quarter of 2014. The Company is eligible to receive an additional $15.0 million milestone payment upon the approval of the MAA.
	The Agreements also include milestone payments related to specified net sales targets, totaling $171.5 million. The sales-based milestones do not meet the definition of a milestone under ASU 2010-17 because the achievement of these milestones is solely dependent on counter-party performance and not on any performance obligations of the Company.
	The Company allocated the $30.0 million upfront fee across the four deliverables based on estimated selling prices and for the quarter ended December 31, 2013, recognized $27.4 million attributable to the license. The remaining $2.6 million was recorded as deferred revenue at December 31, 2013, to be recognized in future periods to the extent services are performed related to the other non-contingent performance deliverables under the agreements.
Hercules Loan and Security Agreements	'
	Upon an event of default, including a change of control, Hercules has the option to accelerate repayment of the Amended Loan Agreement, including payment of any applicable prepayment charges, which range from 1%-3% of the outstanding loan balance and accrued interest, as well as a final payment fee of $1.7 million. This option is considered a contingent put option liability, as the holder of the loan may exercise the option in the event of default, and is considered an embedded derivative, which must be valued and separately accounted for in the Company’s financial statements. As the amendment of the loan agreement was considered an extinguishment, the contingent put option liability associated with the Original Loan Agreement, which had an estimated fair value of $32,000 at the time of the amendment, was written off as a part of the loss on extinguishment, and a new contingent put option liability was established. As of September 30, 2014 and December 31, 2013, the estimated fair value of the contingent put option liability was $325,000 and $334,000, respectively, which was determined by using a risk-neutral valuation model, wherein the fair value of the underlying debt facility is estimated both with and without the presence of the default provisions, holding all other assumptions constant. The resulting difference between the two estimated fair values is the estimated fair value of the default provisions, or the contingent put option. The fair value of the underlying debt facility is estimated by calculating the expected cash flows in consideration of an estimated probability of default and expected recovery rate in default, and discounting such cash flows back to the reporting date using a risk-free rate. The contingent put option liability was recorded as a debt discount to the loan and consequently a reduction to the carrying value of the loan. The contingent put option liability is revalued at the end of each reporting period and any change in the fair value is recognized in interest income and other income (expense), net in the condensed statements of comprehensive loss.
2012 Private Placement Warrants	'
	2012 Private Placement Warrants
	In connection with the Private Placement, completed in June 2012, the Company issued PIPE warrants to purchase up to 2,630,103 shares of common stock. The per share exercise price of the PIPE warrants was $3.40 which equals the closing consolidated bid price of the Company’s common stock on May 29, 2012, the effective date of the Purchase Agreement. The PIPE warrants issued in the Private Placement became exercisable six months after the issuance date, and expire on the five year anniversary of the initial exercisability date. Under the terms of the PIPE warrants, upon certain transactions, including a merger, tender offer, sale of all or substantially all of the assets of the Company or if a person or group shall become the owner of 50% of the Company’s issued and outstanding common stock, which is outside of the Company’s control, each PIPE warrant holder may elect to receive a cash payment in exchange for the warrant, in an amount determined by application of the Black-Scholes option-pricing model. Accordingly, the PIPE warrants were recorded as a liability at fair value, as determined by the Black-Scholes option-pricing model, and then marked to fair value each reporting period, with changes in estimated fair value recorded through interest income and other income (expense), net in the condensed statements of comprehensive loss. The Black-Scholes assumptions used to value the PIPE warrants are disclosed in Note 2.

Investments_and_Fair_Value_Mea1

Investments and Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2014
Text Block [Abstract]	'
Summary of Cash, Cash Equivalents and Investments	'
	The table below summarizes the Company’s cash, cash equivalents and investments (in thousands):
		As of September 30, 2014
		Amortized Cost			Gross Unrealized			Gross Unrealized		Fair
					Gains			Losses		Value
	Cash and cash equivalents:
	Cash	$	70,238		$	—		$	—	$	70,238
	Money market funds		3			—			—		3
	Total cash and cash equivalents		70,241			—			—		70,241
	Marketable securities:
	U.S. government agency securities		15,328			1			—	$	15,329
	Total marketable securities		15,328			1			—	$	15,329
	Total cash, cash equivalents and investments	$	85,569		$	1		$	—	$	85,570
		As of December 31, 2013
		Amortized Cost			Gross Unrealized			Gross Unrealized		Fair
					Gains			Losses		Value
	Cash and cash equivalents:
	Cash	$	88,390		$	—		$	—	$	88,390
	Money market funds		11			—			—		11
	Total cash and cash equivalents		88,401			—			—	$	88,401
	Marketable securities:
	U.S. government agency securities		15,261			1			—		15,262
	Total marketable securities		15,261			1			—	$	15,262
	Total cash, cash equivalents and investments	$	103,662		$	1		$	—	$	103,663
Fair Value of Financial Assets and Liabilities by Level within Fair Value Hierarchy	'
	The following table sets forth the fair value of the Company’s financial assets and liabilities by level within the fair value hierarchy (in thousands):
		As of September 30, 2014
		Fair Value			Level I			Level II		Level III
	Assets
	Money market funds	$	3		$	3		$	—	$	—
	U.S. government agency obligations		15,329			—			15,329		—
	Total assets measured at fair value	$	15,332		$	3		$	15,329	$	—
	Liabilities
	PIPE warrants	$	4,324			—			—	$	4,324
	Contingent put option liability		325			—			—		325
	Total liabilities measured at fair value	$	4,649		$	—		$	—	$	4,649
		As of December 31, 2013
		Fair Value			Level I			Level II		Level III
	Assets
	Money market funds	$	11		$	11		$	—	$	—
	U.S. government agency obligations		15,262			—			15,262		—
	Total assets measured at fair value	$	15,273		$	11		$	15,262	$	—
	Liabilities
	PIPE warrants	$	13,111			—			—	$	13,111
	Contingent put option liability	$	334			—			—	$	334
	Total liabilities measured at fair value	$	13,445		$	—		$	—	$	13,445
Assumptions Used in Black-Scholes Option-Pricing Model to Estimate Fair Value of PIPE Warrants	'
	The following table sets forth the assumptions used in the Black-Scholes option-pricing model to estimate the fair value of the PIPE warrants as of September 30, 2014:
	Market price	$	5.49
	Exercise price	$	3.4
	Risk-free interest rate		1.07	%
	Expected volatility		65	%
	Expected life (in years)		3.17
	Expected dividend yield		0	%
	The following table sets forth the assumptions used in the Black-Scholes option-pricing model to estimate the fair value of the PIPE warrants as of December 31, 2013:
	Market price	$	11.31
	Exercise price	$	3.4
	Risk-free interest rate		1.27	%
	Expected volatility		69	%
	Expected life (in years)		3.92
	Expected dividend yield		0	%
Summary of Changes in Fair Value of Level III Financial Liabilities	'
	The following tables set forth a summary of the changes in the fair value of the Company’s Level III financial liabilities for the three and nine months ended September 30, 2014 and September 30, 2013 (in thousands):
		Three Months			Nine Months
		Ended			Ended
		September 30,			September 30,
		2014			2014
	Fair value—beginning of period	$	11,726		$	13,445
	Change in fair value of PIPE warrants		(6,964	)		(8,787	)
	Change in fair value of contingent put option associated with Amended Loan Agreement with Hercules		(113	)		(9	)
	Fair value—end of period	$	4,649		$	4,649
		Three Months			Nine Months
		Ended			Ended
		September 30,			September 30,
		2013			2013
	Fair value—beginning of period	$	17,889		$	7,500
	Change in fair value of PIPE warrants		(5,459	)		4,973
	Change in fair value of contingent put option associated with Original Loan Agreement with Hercules		(7	)		(50	)
	Fair value—end of period	$	12,423		$	12,423

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Employee Stock Purchase Plan	'
	The Company recorded total stock-based compensation expense for stock options, stock awards and the 2011 Employee Stock Purchase Plan as follows (in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Expenses:
	Research and development	$	568	$	427	$	1,607	$	1,193
	General and administrative		631		449		1,461		1,242
	Total stock-based compensation expense	$	1,199	$	876	$	3,068	$	2,435

Net_Loss_per_Share_of_Common_S1

Net Loss per Share of Common Stock (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Net Loss per Share of Common Stock	'
	The following table sets forth the computation of the Company’s basic and diluted net loss per share of common stock during the three and nine months ended September 30, 2014 and 2013 (in thousands, except for share and per share amounts):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in thousands, except share and per share amounts)
	Numerator
	Net income (loss) used to compute net income (loss) per share:
	Basic	$	671		$	(10,986	)	$	(19,535	)	$	(41,195	)
	Adjustments for change in fair value of warrant liability		(6,418	)		—			(8,241	)		—
	Diluted	$	(5,747	)	$	(10,986	)	$	(27,776	)	$	(41,195	)
	Denominator
	Weighted average shares outstanding used to compute net loss per share:
	Basic		43,469,354			41,462,425			43,332,013			38,635,370
	Dilutive effect of warrants		794,138			—			955,946			—
	Diluted		44,263,492			41,462,425			44,287,959			38,635,370
	Net income (loss) per share—basic	$	0.02		$	(0.26	)	$	(0.45	)	$	(1.07	)
	Net loss per share—diluted	$	(0.13	)	$	(0.26	)	$	(0.63	)	$	(1.07	)
Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share	'
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share of common stock for the periods presented because including them would have been antidilutive:
		September 30,
		2014			2013
	Stock options to purchase common stock		5,313,236			4,923,633
	Restricted stock units		—			65,765
	Common stock warrants		180,155			1,497,939

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2014
Lease Extended Term	'
Schedule of Base Rent Payable Under Lease Amendment	'
	Base rent payable under the Lease Amendment during the Extended Term for the Current Premises will be as follows:
	Period from/to	Monthly Base
		Rent
	May 9, 2016 to May 8, 2017	$	35,961.55
	May 9, 2017 to January 31, 2018		37,040.40
Lease Expansion Space	'
Schedule of Base Rent Payable Under Lease Amendment	'
	Base rent payable under the Lease Amendment for the Expansion Space, commencing August 1, 2014, will be as follows:
	Months of Lease Term	Monthly Base
		Rent
	12-Jan	$	23,001.40
	13-24		23,691.44
	25-36		24,402.18
	37-42		25,134.25

Organization_and_Summary_of_Si2

Organization and Summary of Significant Accounting Policies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Place of incorporation	'Delaware
Date of incorporation	13-Jul-05

Investments_and_Fair_Value_Mea2

Investments and Fair Value Measurement - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Investment Holdings [Line Items]	'	'	'	'	'
Maturity period of non-current marketable securities	'	'	'Beyond one year	'	'
Unrealized losses on available-for-sale securities	$0	'	$0	'	$0
Realized gains or losses in available-for-sale of securities	0	0	0	0	'
Other than temporary impairment for available-for-sale securities	'	'	0	'	0
Amounts reclassified out of other comprehensive income to earnings	$0	$0	$0	$0	'
Maximum	'	'	'	'	'
Investment Holdings [Line Items]	'	'	'	'	'
Contractual maturity period for all investments	'	'	'1 year	'	'1 year

Summary_of_Cash_Cash_Equivalen

Summary of Cash, Cash Equivalents and Investments (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Amortized Cost	$85,569	$103,662
Gross Unrealized Gains	1	1
Gross Unrealized Losses	'	'
Fair Value	85,570	103,663
Cash and cash equivalents	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Amortized Cost	70,241	88,401
Gross Unrealized Gains	'	'
Gross Unrealized Losses	'	'
Fair Value	70,241	88,401
Cash and cash equivalents | Cash	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Amortized Cost	70,238	88,390
Gross Unrealized Gains	'	'
Gross Unrealized Losses	'	'
Fair Value	70,238	88,390
Cash and cash equivalents | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Amortized Cost	3	11
Gross Unrealized Gains	'	'
Gross Unrealized Losses	'	'
Fair Value	3	11
Marketable securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Amortized Cost	15,328	15,261
Gross Unrealized Gains	1	1
Gross Unrealized Losses	'	'
Fair Value	15,329	15,262
Marketable securities | U.S. government agency securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Amortized Cost	15,328	15,261
Gross Unrealized Gains	1	1
Gross Unrealized Losses	'	'
Fair Value	$15,329	$15,262

Fair_Value_of_Financial_Assets

Fair Value of Financial Assets and Liabilities by Level within Fair Value Hierarchy (Detail) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	$15,332	$15,273
Total liabilities measured at fair value	4,649	13,445
Contingent put option liability	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	325	334
PIPE warrants	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	4,324	13,111
Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	3	11
U.S. government agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	15,329	15,262
Level I	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	3	11
Total liabilities measured at fair value	0	'
Level I | Contingent put option liability	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	0	'
Level I | PIPE warrants	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	0	'
Level I | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	3	11
Level I | U.S. government agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	0	'
Level II	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	15,329	15,262
Total liabilities measured at fair value	0	'
Level II | Contingent put option liability	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	0	'
Level II | PIPE warrants	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	0	'
Level II | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	0	'
Level II | U.S. government agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	15,329	15,262
Level III	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	0	'
Total liabilities measured at fair value	4,649	13,445
Level III | Contingent put option liability	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	325	334
Level III | PIPE warrants	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total liabilities measured at fair value	4,324	13,111
Level III | Money market funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	0	'
Level III | U.S. government agency obligations	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total assets measured at fair value	$0	'

Assumptions_Used_in_BlackSchol

Assumptions Used in Black-Scholes Option-Pricing Model to Estimate Fair Value of PIPE Warrants (Detail) (PIPE warrants, USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
PIPE warrants	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Market price	$5.49	$11.31
Exercise price	$3.40	$3.40
Risk-free interest rate	1.07%	1.27%
Expected volatility	65.00%	69.00%
Expected life (in years)	'3 years 2 months 1 day	'3 years 11 months 1 day
Expected dividend yield	0.00%	0.00%

Summary_of_Changes_in_Fair_Val

Summary of Changes in Fair Value of Level III Financial Liabilities (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'	'
Change in fair value of PIPE warrants	($6,418)	'	($8,241)	'
Level III	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'	'
Fair value-beginning of period	11,726	17,889	13,445	7,500
Change in fair value of PIPE warrants	-6,964	-5,459	-8,787	4,973
Fair value-end of period	4,649	12,423	4,649	12,423
Level III | Amended Loan Agreement with Hercules	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'	'
Change in fair value of contingent put option	-113	'	-9	'
Level III | Original Loan Agreement with Hercules	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'	'
Change in fair value of contingent put option	'	($7)	'	($50)

Research_Grant_Agreement_Addit

Research Grant Agreement - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	31-May-11	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Research and Development [Abstract]	'	'	'	'	'	'
Attributable revenue for product development from US Army Medical Research and Material Command	$5,600,000	'	'	'	'	$5,600,000
Research grant revenue	'	$0	$548,000	$0	$1,895,000	'

Collaboration_Agreement_Additi

Collaboration Agreement - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended		3 Months Ended
	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
				Up Front Fee	Zalviso	Zalviso	Marketing Authorization Application
						Europe
Revenue Recognition, Milestone Method [Line Items]	'	'	'	'	'	'	'
Aggregate potential payments	$30,000,000	'	'	'	$28,500,000	$20,000,000	'
Milestone payment to be received	'	5,000,000	5,000,000	'	'	'	'
Additional payments receivable	'	15,000,000	15,000,000	'	'	'	'
Additional payments receivable based on efforts and targets	'	200,000,000	200,000,000	'	'	'	'
Milestone payments related to net sales net sales target	'	'	171,500,000	'	'	'	'
Milestone payments related to regulatory and product development	'	'	28,500,000	'	'	'	'
License revenue recognized	'	'	'	27,400,000	'	'	'
Deferred revenue	'	2,600,000	2,600,000	2,600,000	'	'	'
Recognized deferred revenue related to research and development	'	4,800,000	5,000,000	'	'	'	'
Revenue recognized	'	4,825,000	4,991,000	'	'	'	4,600,000
Milestone payments received	'	$0	$0	'	'	'	'

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Jun. 30, 2011

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Dec. 16, 2013

Jun. 29, 2011

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 29, 2011

Dec. 31, 2011

Sep. 30, 2014

Dec. 31, 2013

Dec. 16, 2013

Sep. 30, 2014

Dec. 16, 2013

Jun. 16, 2014

Sep. 24, 2014

Hercules Warrants

Hercules Warrants

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Hercules Loan and Security Agreements

Amended Loan And Security Agreement

Amended Loan And Security Agreement

Amended Loan And Security Agreement

Amended Loan And Security Agreement

Amended Loan And Security Agreement

Amended Loan And Security Agreement

Amended Loan And Security Agreement

Tranche

Maximum

Minimum

Prior to December 16, 2014

After December 16, 2014, but Prior to December 16, 2015

After December 16, 2015

Hercules Warrants

First Tranche

Second Tranche

Prime Rate

First Tranche

Second Tranche

Third Tranche

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

$20,000,000

'

'

'

'

'

'

$10,000,000

$10,000,000

'

'

'

'

$15,000,000

$10,000,000

'

Number of tranches

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants exercisable term

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'7 years

'

'

'

'

'

'

'

'

'

Debt, interest rate percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.50%

'

'

'

'

'

'

'

'

'

Warrants exercise price per share

'

'

'

'

'

$3.06

$6.79

'

'

$6.79

'

'

'

'

'

'

'

'

'

$3.06

'

'

'

'

'

'

'

'

'

Warrants to purchase common stock

'

'

'

'

'

274,508

'

'

'

'

'

'

'

'

'

'

'

'

'

274,508

'

'

'

'

'

'

'

'

'

Maximum borrowing capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

40,000,000

'

'

'

'

Proceeds used for repayment of obligation

'

'

'

5,789,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,600,000

'

'

New debt at estimated fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

24,900,000

14,300,000

'

'

'

'

'

Borrowing capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,000,000

Payment terms

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'Payments under the Amended Loan Agreement are interest only until April 1, 2015 (which will be extended until January 1, 2016 if the Company achieves the Milestone on or before April 1, 2015) followed by equal monthly payments of principal and interest through the scheduled maturity date on October 1, 2017 (which would be extended until January 1, 2018 if the Company achieves the Milestone on or prior to April 1, 2015), or the Loan Maturity Date. In addition, a final payment equal to $1.7 million will be due on the Loan Maturity Date

'

'

'

'

'

'

Interest rate terms

'

'

'The interest rate for each tranche will be calculated at a rate equal to the greater of either (i) 9.10% plus the prime rate as reported from time to time in The Wall Street Journal minus 5.25%, and (ii) 9.10%.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.10%

'

'

'

Basis spread on variable interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.25%

'

'

'

Final payment due on maturity date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,700,000

'

'

'

'

'

'

Prepayment terms

'

'

'

'

'

'

'

'

'

'If the Company prepays the Amended Loan Agreement prior to maturity, it will pay Hercules a prepayment charge, based on a percentage of the then outstanding principal balance, equal to 3% if the prepayment occurs prior to December 16, 2014, 2% if the prepayment occurs after December 16, 2014, but prior to December 16, 2015, or 1% if the prepayment occurs after December 16, 2015.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Prepayment charge on loan percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

2.00%

1.00%

'

'

'

'

'

'

'

'

'

'

Convertible debt amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible debt terms

'

'

'

'

'

'

'

'

'

'Subject to certain conditions and limitations set forth in the Loan Agreement, the Company has the right to convert up to $5.0 million of scheduled principal installments under the Notes into freely tradeable shares of the Companybs common stock (bCommon Stockb). The number of shares of Common Stock that would be issued upon conversion of the Notes would be equal to the number determined by dividing (x) the product of (A) the principal amount to be paid in shares of Common Stock and (B) 103%, by (y) $9.30 (subject to certain proportional adjustments as provided for in the Loan Agreement).

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Default interest rate

'

'

'

'

'

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrants outstanding

'

'

'

'

'

'

176,730

176,730

'

176,730

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Prepayment charges for accelerated repayment of credit facility, percentage of outstanding balance

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

1.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Final payment fee for early repayment of facility

'

'

'

'

'

'

'

'

'

1,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Contingent put option liability

325,000

'

325,000

'

334,000

[1]

'

'

325,000

'

325,000

'

334,000

32,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, amount outstanding

'

'

'

'

'

'

'

25,000,000

'

25,000,000

'

15,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of debt discounts

'

'

'

'

'

'

'

231,000

85,000

504,000

290,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest expense

$816,000

$348,000

$1,818,000

$1,205,000

'

'

'

$813,000

$348,000

$1,800,000

$1,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

The condensed balance sheet as of December 31, 2013 has been derived from the audited financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.

Warrants_Additional_Informatio

Warrants - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

2 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Feb. 28, 2013

Sep. 30, 2014

Sep. 30, 2008

Sep. 30, 2014

Sep. 30, 2014

Jun. 30, 2011

Jul. 31, 2013

Sep. 30, 2014

Jun. 30, 2012

Sep. 30, 2014

Mar. 31, 2007

Sep. 30, 2014

Mar. 31, 2007

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Pinnacle [Member]

Pinnacle [Member]

Pinnacle [Member]

Pinnacle [Member]

Pinnacle [Member]

Hercules Warrants

Hercules Warrants

Hercules Warrants

PIPE warrants

PIPE warrants

Series Warrants

Series Warrants

Series Warrants

Series Warrants

2012 Private Placement

2012 Private Placement

2012 Private Placement

2012 Private Placement

2012 Private Placement

Pinnacle Loan and Security Agreement

Pinnacle Loan and Security Agreement

Pinnacle Loan and Security Agreement

Common Stock

Series B Preferred Stock

Series A Preferred Stock

Common Stock

Class of Warrant or Right [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

PIPE warrants to purchase shares

'

'

'

'

'

'

'

228,264

56,250

274,508

'

'

'

'

'

3,425

2,500

'

'

'

'

'

'

PIPE warrants, exercise price per share

'

'

'

'

'

'

'

$3.94

$16

$3.06

'

$6.79

$3.40

'

$10

'

'

'

'

'

'

'

'

Fair value of warrants

'

'

'

'

'

'

'

'

'

'

'

$1,100,000

'

'

'

$1,000

'

'

'

'

'

'

'

Warrants outstanding

'

'

'

'

'

0

'

'

'

'

'

176,730

2,630,103

'

'

'

'

3,425

1,359,514

'

1,359,514

'

'

Warrants, expiration date

'

'

'

'

'

'

'

'

'

'

'

31-Dec-18

'

'

'

'

'

1-Mar-17

'

'

1-Nov-17

'

'

Loan and security agreement, maximum potential borrowings

'

'

'

'

'

'

12,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock warrants exercised

135,000

'

135,000

'

228,264

'

'

'

'

'

274,508

'

'

'

'

'

'

'

'

'

'

'

'

Common stock issued upon exercise of warrants

91,488

'

91,488

'

58,580

'

'

'

'

'

183,404

'

'

'

'

'

'

'

'

'

'

'

'

Warrants exercisable term

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'6 months

'

'

'

'

'

'

'

'

'

Warrants strike price

'

'

'

'

'

'

'

'

'

'

'

6.79

'

'

'

'

'

'

'

'

'

'

'

Warrants stock issuance price

'

'

'

'

'

'

'

'

'

'

'

$9.67

'

'

'

'

'

'

'

'

'

'

'

Risk-free interest rate

'

'

'

'

'

'

'

'

'

'

'

1.55%

'

'

'

'

'

'

'

'

'

'

'

Expected volatility

'

'

'

'

'

'

'

'

'

'

'

71.00%

'

'

'

'

'

'

'

'

'

'

'

Expected dividend yield

'

'

'

'

'

'

'

'

'

'

'

0.00%

'

'

'

'

'

'

'

'

'

'

'

Warrant expiration period after the initial exercisability date

'

'

'

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

'

Exercise of warrants description

'

'

'

'

'

'

'

'

'

'

'

'

'

'Under the terms of the PIPE warrants, upon certain transactions, including a merger, tender offer, sale of all or substantially all of the assets of the Company or if a person or group shall become the owner of 50% of the Company's issued and outstanding common stock, which is outside of the Company's control, each PIPE warrant holder may elect to receive a cash payment in exchange for the warrant, in an amount determined by application of the Black-Scholes option-pricing model.

'

'

'

'

'

'

'

'

'

Estimated fair value of PIPE warrants upon execution of Purchase Agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,800,000

'

5,800,000

'

'

Estimated fair value of PIPE warrants at end of period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,300,000

'

4,300,000

'

13,100,000

Income (expense) recorded related to change in fair value of PIPE warrants

$6,556,000

($2,328,000)

$8,153,000

($13,340,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$6,556,000

($2,328,000)

$8,153,000

($13,340,000)

'

Employee_Stock_Purchase_Plan_D

Employee Stock Purchase Plan (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$1,199	$876	$3,068	$2,435
Research and development	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	568	427	1,607	1,193
General and administrative	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock-based compensation expense	$631	$449	$1,461	$1,242

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail)	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Shares available for grant	1,160,866
Number of stock options outstanding	5,313,236
Restricted stock unit outstanding	0

Computation_of_Basic_and_Dilut

Computation of Basic and Diluted Net Loss per Share of Common Stock (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income (loss) used to compute net income (loss) per share:	'	'	'	'
Basic	$671	($10,986)	($19,535)	($41,195)
Adjustments for change in fair value of warrant liability	-6,418	'	-8,241	'
Diluted	($5,747)	($10,986)	($27,776)	($41,195)
Weighted average shares outstanding used to compute net loss per share:	'	'	'	'
Basic	43,469,354	41,462,425	43,332,013	38,635,370
Dilutive effect of warrants	794,138	'	955,946	'
Diluted	44,263,492	41,462,425	44,287,959	38,635,370
Net income (loss) per share-basic	$0.02	($0.26)	($0.45)	($1.07)
Net loss per share-diluted	($0.13)	($0.26)	($0.63)	($1.07)

Outstanding_Shares_of_Common_S

Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Detail)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Stock options to purchase common stock	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Shares of common stock equivalents excluded from the computation of diluted net loss per share of common stock	5,313,236	4,923,633
Restricted stock units	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Shares of common stock equivalents excluded from the computation of diluted net loss per share of common stock	'	65,765
Common stock warrants	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Shares of common stock equivalents excluded from the computation of diluted net loss per share of common stock	180,155	1,497,939

Manufacturing_Agreements_Addit

Manufacturing Agreements - Additional Information (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Long-term Purchase Commitment [Line Items]	'	'
Service agreement date	'2013-01	'
Product requirement percentage under Services Agreement	80.00%	'
Service Agreement expiration date	31-Dec-17	'
Services Agreement renewal period	'2 years	'
Services Agreement termination notice period	'18 months	'
Property and equipment, net	$9,467	$5,179	[1]
Patheon's Cincinnati Facility	'	'
Long-term Purchase Commitment [Line Items]	'	'
Property and equipment, net	$3,600	'
[1]	The condensed balance sheet as of December 31, 2013 has been derived from the audited financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2013.

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended
	31-May-14
	sqft
Lease Extended Term	'
Commitment And Contingencies [Line Items]	'
Area of premises leased under lease agreement	13,787
Extended term of lease agreement	'20 months 22 days
Lease expiration date	31-Jan-18
Additional term of extension in Lease Amendment	'5 years
Lease Expansion Space	'
Commitment And Contingencies [Line Items]	'
Area of premises leased under lease agreement	12,106
Term of lease agreement	'42 months
Lease commencement date	1-Aug-14

Commitments_and_Contingencies_2

Commitments and Contingencies - Schedule of Base Rent Payable Under Lease Amendment (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Lease Extended Term | May 9, 2016 to May 8, 2017	'
Operating Leased Assets [Line Items]	'
Monthly Base Rent payable	$35,961.55
Lease Extended Term | May 9, 2017 to January 31, 2018	'
Operating Leased Assets [Line Items]	'
Monthly Base Rent payable	37,040.40
Lease Expansion Space	'
Operating Leased Assets [Line Items]	'
Lease Term Months from 1-12	23,001.40
Lease Term Months from 13-24	23,691.44
Lease Term Months from 25-36	24,402.18
Lease Term Months from 37-42	$25,134.25