Viracta Therapeutics (VIRX) 10-Q 5 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	SNSS
Entity Registrant Name	SUNESIS PHARMACEUTICALS INC
Entity Central Index Key	1061027
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		72,960,303

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$18,784	$22,186	[1]
Marketable securities	21,009	20,795	[1]
Prepaids and other current assets	1,478	1,223	[1]
Total current assets	41,271	44,204	[1]
Property and equipment, net	31	42	[1]
Total assets	41,302	44,246	[1]
Current liabilities:
Accounts payable	2,121	3,177	[1]
Accrued clinical expense	2,225	3,112	[1]
Accrued compensation	1,029	2,287	[1]
Other accrued liabilities	2,781	3,087	[1]
Current portion of deferred revenue	3,418	3,418	[1]
Current portion of notes payable	713	9,257	[1]
Warrant liability	3,632	3,543	[1]
Total current liabilities	15,919	27,881	[1]
Non-current portion of deferred revenue	1,709	2,563	[1]
Non-current portion of notes payable	6,881
Commitments			[1]
Stockholders’ equity:
Common stock	7	7	[1]
Additional paid-in capital	548,616	536,499	[1]
Accumulated other comprehensive loss	-5	-7	[1]
Accumulated deficit	-531,825	-522,697	[1]
Total stockholders’ equity	16,793	13,802	[1]
Total liabilities and stockholders’ equity	$41,302	$44,246	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2014 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, 2014.

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue:
License and other revenue	$854	$1,995
Total revenues	854	1,995
Operating expenses:
Research and development	4,512	7,552
General and administrative	5,111	3,417
Total operating expenses	9,623	10,969
Loss from operations	-8,769	-8,974
Interest expense	-239	-547
Other income (expense), net	-120	-5,052
Net loss	-9,128	-14,573
Unrealized gain (loss) on available-for-sale securities	2	7
Comprehensive loss	-9,126	-14,566
Basic and diluted loss per common share:
Net loss	($9,128)	($14,573)
Shares used in computing basic and diluted loss per common share	67,641	56,313
Basic and diluted loss per common share	($0.13)	($0.26)

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Cash flows from operating activities
Net loss	($9,128)		($14,573)
Adjustments to reconcile loss to net cash used in operating activities:
Stock-based compensation expense	1,964		1,306
Depreciation and amortization	11		5
Amortization of debt discount and debt issuance costs	44		116
Increase in fair value of warrant liability	89		4,937
Changes in operating assets and liabilities:
Prepaids and other assets	-259		68
Accounts payable	-1,056		58
Accrued clinical expense	-887		-1,113
Accrued compensation	-1,258		-848
Other accrued liabilities	-268		599
Deferred revenue	-853		-1,988
Net cash used in operating activities	-11,601		-11,433
Cash flows from investing activities
Purchases of property and equipment			-23
Purchases of marketable securities	-7,942		-12,303
Proceeds from maturities of marketable securities	7,730		16,180
Net cash (used in) provided by investing activities	-212		3,854
Cash flows from financing activities
Principal payments on notes payable	-1,642		-2,261
Proceeds from issuance of common stock and warrants in underwritten offering, net			40,022
Proceeds from issuance of common stock through controlled equity offering facilities, net	10,011		4,726
Proceeds from exercise of warrants, stock options and stock purchase rights	42		325
Net cash provided by financing activities	8,411		42,812
Net (decrease) increase in cash and cash equivalents	-3,402		35,233
Cash and cash equivalents at beginning of period	22,186	[1]	15,121
Cash and cash equivalents at end of period	18,784		50,354
Supplemental disclosure of non-cash activities
Fair value of warrants issued in connection with notes payable	$100
[1]	The condensed consolidated balance sheet as of December 31, 2014 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, 2014.

Company_Overview

Company Overview	3 Months Ended
	Mar. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Company Overview	1. Company Overview
	Description of Business
	Sunesis Pharmaceuticals, Inc. (the “Company” or “Sunesis”) was incorporated in the state of Delaware on February 10, 1998, and its facilities are located in South San Francisco, California. Sunesis is a biopharmaceutical company focused on the development and commercialization of new oncology therapeutics for the treatment of solid and hematologic cancers. The Company’s primary activities since incorporation have been conducting research and development internally and through corporate collaborators, in-licensing and out-licensing pharmaceutical compounds and technology, conducting clinical trials and raising capital.
	In October 2014, the Company announced the results of a Phase 3, multi-national, randomized, double-blind, placebo-controlled, clinical trial of vosaroxin in combination with cytarabine in patients with relapsed or refractory acute myeloid leukemia (the “VALOR trial”). The trial did not meet its primary endpoint of demonstrating a statistically significant improvement in overall survival, but based upon the results of other predefined analyses of the data, Sunesis plans to meet with its European Rapporteur and Co-Rapporteur, who are two appointed members of the EMA’s Committee of Human Medicinal Products, in mid-2015 to discuss the planned filing of a marketing authorization application (“MAA”) with the European Medicines Agency (“EMA”). The Company is also currently engaged in discussions with the U.S. Food and Drug Administration (“FDA”) to determine a potential regulatory path forward in the United States.
	Significant Risks and Uncertainties
	The Company has incurred significant losses and negative cash flows from operations since its inception, and as of March 31, 2015, had cash, cash equivalents and marketable securities totaling $39.8 million and an accumulated deficit of $531.8 million.
	The Company will need to raise substantial additional capital to pursue a regulatory strategy for the potential commercialization of QINPREZOTM (vosaroxin), its product candidate for the potential treatment of acute myeloid leukemia, and to continue the development of vosaroxin and the Company’s other programs. The Company expects to finance its future cash needs primarily through equity issuances, debt arrangements, one or more possible licenses, collaborations or other similar arrangements with respect to development and/or commercialization rights to vosaroxin and its other development programs, or a combination of the above. However, the Company does not know whether additional funding will be available on acceptable terms, or at all. If the Company is unable to raise required funding on acceptable terms or at all, it will need to reduce operating expenses, enter into a collaboration or other similar arrangement with respect to development and/or commercialization rights to vosaroxin, outlicense intellectual property rights to vosaroxin or our other development programs, sell unsecured assets, or a combination of the above, or be forced to delay or reduce the scope of its vosaroxin development program, potentially including any regulatory filings related to the VALOR trial, and/or limit or cease its operations.
	Concentrations of Credit Risk
	In accordance with its investment policy, the Company invests cash that is not currently being used for operational purposes. The policy allows for the purchase of low risk debt securities issued by: (a) the United States and certain European governments and government agencies, and (b) highly rated banks and corporations, denominated in U.S. dollars, Euros or British pounds, subject to certain concentration limits. The policy limits maturities of securities purchased to no longer than 24 months and the weighted average maturity of the portfolio to 12 months. Management believes these guidelines ensure both the safety and liquidity of any investment portfolio the Company may hold.
	Financial instruments that potentially subject the Company to concentrations of credit risk generally consist of cash, cash equivalents and marketable securities. The Company is exposed to credit risk in the event of default by the institutions holding its cash, cash equivalents and any marketable securities to the extent of the amounts recorded in the balance sheets.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. The financial statements include all adjustments (consisting only of normal recurring adjustments) that management believes are necessary for a fair presentation of the periods presented. The balance sheet as of December 31, 2014 was derived from the audited financial statements as of that date. These interim financial results are not necessarily indicative of results to be expected for the full year or any other period. These unaudited condensed consolidated financial statements and the notes accompanying them should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014.
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), that will supersede most existing revenue recognition guidance under US GAAP. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach. Entities electing the full retrospective adoption will apply the standard to each period presented in the financial statements. This means that entities will have to apply the new guidance as if it had been in effect since the inception of all its contracts with customers presented in the financial statements. Entities that elect the modified retrospective approach will apply the guidance retrospectively only to the most current period presented in the financial statements. This means that entities will have to recognize the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings at the date of initial application. The new revenue standard will be applied to contracts that are in progress at the date of initial application. As currently issued, the standard will be effective for annual and interim periods beginning after December 15, 2016. The Company has yet to evaluate which adoption method it plans to use or the potential effect of the new standard on its consolidated financial statements. On April 1, 2015, the FASB voted to propose to defer the effective date of the new revenue recognition standard by one year.
	In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern (“ASU 2014-15”), which will require a reporting entity to evaluate, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the reporting entity's ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. The standard will be effective for annual and interim periods beginning after December 15, 2016, with early adoption permitted. The Company has yet to evaluate the potential effect of the new standard on its consolidated financial statements.
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, Sunesis Europe Limited, a United Kingdom corporation, and Sunesis Pharmaceuticals (Bermuda) Ltd., a Bermuda corporation, as well as a Bermuda limited partnership, Sunesis Pharmaceuticals International LP. All intercompany balances and transactions have been eliminated in consolidation.
	Segment Reporting
	Management has determined that the Company operates as a single reportable segment.
	Significant Estimates and Judgments
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s consolidated financial statements and accompanying notes thereto. Actual results could differ materially from these estimates. Estimates, assumptions and judgments made by management include those related to the valuation of equity and related instruments, revenue recognition, stock-based compensation and clinical trial accounting.
	Cash Equivalents and Marketable Securities
	Invoices for certain services provided to the Company are denominated in foreign currencies. To manage the risk of future movements in foreign exchange rates that would affect such amounts, the Company may purchase certain European currencies or highly-rated investments denominated in those currencies, subject to similar criteria as for other investments defined in the Company’s investment policy. There is no guarantee that the related gains and losses will substantially offset each other, and the Company may be subject to significant exchange gains or losses as currencies fluctuate from quarter to quarter. To date, the Company has purchased Euros and Euro-denominated obligations of foreign governments and corporate debt. As of March 31, 2015 and December 31, 2014, the Company held cash and investments denominated in Euros with an aggregate fair value of $0.7 million and $0, respectively. Any cash, cash equivalent and marketable securities balances denominated in foreign currencies are recorded at their fair value based on the current exchange rate as of each balance sheet date. The resulting exchange gains or losses and those from amounts payable for services originally denominated in foreign currencies are recorded in other income (expense), net in the statements of operations and comprehensive loss.
	Fair Value Measurements
	The Company measures cash equivalents, marketable securities and warrant liabilities at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, in accordance with applicable GAAP:
	Level 1 - quoted prices (unadjusted) in active markets for identical assets and liabilities that can be accessed at the measurement date.
	Level 2 - inputs other than quoted prices included within Level 1 that are observable, either directly or indirectly.
	Level 3 - unobservable inputs.
	The Company’s Level 2 valuations of marketable securities are generally derived from independent pricing services based upon quoted prices in active markets for similar securities, with prices adjusted for yield and number of days to maturity, or based on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets.
	The fair value of the Company’s liability for warrants issued in connection with an underwritten offering completed in October 2010 (the “2010 Offering”) is determined using the Black-Scholes model, which requires inputs such as the expected term of the warrants, share price volatility, expected dividend yield and risk-free interest rate. As some of these inputs are unobservable, and require significant analysis and judgment to measure, these variables are classified as Level 3.
	The Company does not measure cash, prepayments, accounts payable, accrued liabilities, deferred revenue and notes payable at fair value, as their carrying amounts approximated their fair value as of March 31, 2015 and December 31, 2014.

Loss_per_Common_Share

Loss per Common Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Loss per Common Share	3. Loss per Common Share
	Basic loss per common share is calculated by dividing net loss by the weighted-average number of common shares outstanding for the period. Diluted loss per common share is computed by dividing (a) net loss, less any anti-dilutive amounts recorded during the period for the change in the fair value of warrant liabilities, by (b) the weighted-average number of common shares outstanding for the period plus dilutive potential common shares as determined using the treasury stock method for options and warrants to purchase common stock.
	The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted loss per common share because their inclusion would have had an anti-dilutive effect (in thousands):
		Three months ended
		March 31,
		2015		2014
	Warrants to purchase shares of common stock		11,898		19,171
	Options to purchase shares of common stock		10,649		9,287
	Outstanding securities not included in calculations		22,547		28,458

Financial_Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Financial Instruments	4. Financial Instruments
	Financial Assets
	The following tables summarize the estimated fair value of the Company’s financial assets measured on a recurring basis as of the dates indicated, which were comprised solely of available-for-sale marketable securities with remaining contractual maturities of one year or less (in thousands):
	31-Mar-15		Input Level		Amortized				Gross		Gross			Estimated Fair
					Cost				Unrealized		Unrealized			Value
									Gains		Losses
	Money market funds		Level 1		$	6,340			$	—	$	—		$	6,340
	U.S. certificates of deposit		Level 1			8,905				—		—			8,905
	U.S. corporate debt obligations		Level 2			10,356				—		(6	)		10,350
	U.S. commercial paper		Level 2			1,999				—		—			1,999
	Total available-for-sale securities					27,600				—		(6	)		27,594
	Less amounts classified as cash equivalents					(6,585	)			—		—			(6,585	)
	Amounts classified as marketable securities				$	21,015			$	—	$	(6	)	$	21,009
	31-Dec-14		Input Level		Amortized				Gross		Gross			Estimated Fair
					Cost				Unrealized		Unrealized			Value
									Gains		Losses
	Money market funds		Level 1		$	9,287			$	—	$	—		$	9,287
	U.S. certificates of deposit		Level 1		$	6,360				—		—		$	6,360
	U.S. corporate debt obligations		Level 2			11,789				—		(7	)		11,782
	U.S. commercial paper		Level 2			2,898				—		—			2,898
	Total available-for-sale securities					30,334				—		(7	)		30,327
	Less amounts classified as cash equivalents					(9,532	)			—		—			(9,532	)
	Amounts classified as marketable securities				$	20,802			$	—	$	(7	)	$	20,795
	The following table summarizes the available-for-sale securities that were in an unrealized loss position as of the date indicated, having been in such a position for less than 12 months, and none having been deemed to be other-than-temporarily impaired (in thousands):
	31-Mar-15		Gross				Estimated Fair
			Unrealized				Value
			Losses
	U.S. corporate debt obligations		$	6			$	8,896
	No significant facts or circumstances have arisen to indicate that there has been any deterioration in the creditworthiness of the issuers of these securities. The gross unrealized losses are not considered to be significant and have generally been for relatively short durations. The Company does not intend to sell these securities before maturity and it is not likely that they will need to be sold prior to the recovery of their amortized cost basis. There were no sales of available-for-sale securities during either the three months ended March 31, 2015 or 2014.
	Financial Liabilities
	The following table summarizes the inputs and assumptions and estimated fair value of the Company’s financial liabilities measured on a recurring basis as of the dates indicated, which were comprised solely of a liability for warrants issued in connection with the 2010 Offering:
		March 31,				December 31,
		2015				2014
	Inputs and assumptions:
	Fair market value of Company’s common stock	$	2.45			$	2.55
	Exercise price	$	2.52			$	2.52
	Expected term (years)		0.5				0.8
	Expected volatility		193.4	%			144.9	%
	Risk-free interest rate		0.1	%			0.2	%
	Expected dividend yield		0	%			0	%
	Fair value:
	Estimated fair value per warrant share	$	1.24			$	1.21
	Shares underlying outstanding warrants classified as		2,920				2,920
	liabilities (in thousands)
	Total estimated fair value of outstanding warrants	$	3,632			$	3,543
	(in thousands)
	The warrants have been classified as a liability on the Company’s balance sheet due to the potential for the warrants to be settled in cash upon the occurrence of certain transactions specified in the warrant agreements. At each balance sheet date, the estimated fair value of the outstanding warrants is determined using the Black-Scholes model and recorded to the balance sheet, with the change in fair value recorded to other income (expense), net in the statements of operations and comprehensive loss, and the fair value of warrant exercises transferred to additional paid-in capital. During the three months ended March 31, 2015, no warrants to purchase shares of common stock issued in connection with the 2010 Offering were exercised.
	The Black-Scholes model requires Level 3 inputs such as the expected term of the warrants and share price volatility. These inputs are subjective and generally require significant analysis and judgment to develop. Any changes in these inputs could result in a significantly higher or lower fair value measurement.
	The following table summarizes the changes in the fair value of the Company’s Level 3 financial liabilities for the period indicated (in thousands):
		Warrant
		Liability
	Balance as of December 31, 2014	$	3,543
	Change in fair value of warrant liability		89
	Exercise of warrants		—
	Balance as of March 31, 2015	$	3,632

Royalty_Agreement

Royalty Agreement	3 Months Ended
	Mar. 31, 2015
Revenue Recognition [Abstract]
Royalty Agreement	5. Royalty Agreement
	In March 2012, the Company entered into a Revenue Participation Agreement (the “Royalty Agreement”), with RPI Finance Trust (“RPI”), an entity related to Royalty Pharma. In September 2012, pursuant to the provisions of the Royalty Agreement, RPI made a $25.0 million cash payment to the Company. The payment, less $3.1 million representing the fair value of the warrants granted under the arrangement, was initially classified as deferred revenue and is being amortized to revenue over the related performance period.
	Revenue participation right payments will be made to RPI when and if vosaroxin is commercialized, at a rate of 6.75% of net sales of vosaroxin, on a product-by-product and country-by-country basis world-wide through the later of: (a) the expiration of the last to expire of certain specifically identified patents; (b) 10 years from the date of first commercial sale of such product in such country; or (c) the expiration of all applicable periods of data, market or other regulatory exclusivity in such country with respect to such product.

License_Agreements

License Agreements	3 Months Ended
	Mar. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
License Agreements	6. License Agreements
	Biogen Idec
	In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen Idec MA, Inc. (the “Biogen Idec 2nd ARCA”), to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize SNS-062, a BTK inhibitor synthesized under the first amended and restated collaboration agreement with Biogen Idec (the “Biogen Idec 1st ARCA”), solely for oncology indications. The Company may be required to make a $2.5 million milestone payment depending on its development of SNS-062 and royalty payments depending on related product sales of SNS-062. All other of Sunesis’ rights and obligations contained in the Biogen Idec 1st ARCA remain unchanged, except that potential future royalty payments to Sunesis were reduced to equal those amounts due to Biogen Idec for potential future sales of SNS-062.
	Millennium
	In March 2011, Millennium Pharmaceuticals, Inc., a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited (“Millennium”) purchased and exclusively licensed Biogen Idec’s rights to a PDK1 inhibitor program and a pan-Raf inhibitor program which were both originally developed through a collaboration agreement between Sunesis and Biogen Idec. In January 2014, the Company entered into an amended and restated license agreement with Millennium (the “Amended Millennium Agreement”), to provide the Company with an exclusive worldwide license to develop and commercialize preclinical inhibitors of PDK1. In connection with the execution of the Amended Millennium Agreement, the Company paid an upfront fee and may be required to make up to $9.2 million in pre-commercialization milestone payments depending on its development of PDK1 inhibitors and royalty payments depending on related product sales, if any.
	With respect to the pan-Raf inhibitor program, the Company may in the future receive up to $57.5 million in pre-commercialization event-based payments related to the development by Millennium of the first two indications for each of the licensed products directed against the Raf target and royalty payments depending on related product sales. Under this program, Millennium is currently conducting Phase 1 clinical studies of an oral investigative drug, MLN2480.

Notes_Payable

Notes Payable	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Notes Payable	7. Notes Payable
	In October 2011, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Oxford Finance LLC, Silicon Valley Bank and Horizon Technology Finance Corporation (collectively, the “Lenders”), under which the Company could borrow up to $25.0 million in two tranches (the “Loan Facility”). The first tranche of $10.0 million was funded upon closing of the transaction in October 2011, and the second tranche of $15.0 million was drawn by the Company in September 2012. In connection with the Loan Agreement, the Lenders were granted a perfected first priority security interest in substantially all of the Company’s assets, other than intellectual property.
	The interest rates for the first and second tranche are 8.95% and 9.00% per annum, respectively. Payments under the Loan Agreement are monthly in arrears and were interest-only until February 1, 2013, and were to be followed by 32 equal monthly payments of principal and interest from March 1, 2013 to the original maturity date of October 1, 2015. In addition, a final payment equal to $937,500 was to be due on October 1, 2015, or such earlier date as specified in the Loan Agreement.
	On February 27, 2015, the Company entered into an amendment (the “Amendment”), to the Loan Agreement with the Lenders. The Amendment modifies the loan repayment terms to be interest-only from March 1, 2015 to February 1, 2016, followed by eight equal monthly payments of principal and interest through the new maturity date of October 1, 2016. In addition, the final payment was increased to $1,162,500, and will become due on the new maturity date, or such earlier date specified in the Loan Agreement. If the Company repays all or a portion of the loan prior to February 29, 2016 as part of a refinancing with another lender, a prepayment fee equal to 2% of the then outstanding principal balance will be due to the Lenders. The remaining balance of the final payment that has yet to be expensed is being accreted as interest expense through the new maturity date using the effective interest method.
	In connection with the Amendment, the Lenders were issued five-year warrants to purchase an aggregate of up to 61,467 shares of the Company’s common stock at a per share exercise price of $2.22. The fair value of these warrants was estimated to be $0.1 million using the Black-Scholes valuation model. The fair value of these warrants was recorded at issuance as a debt discount within notes payable and an increase to additional paid-in capital on the Company’s balance sheet. The balance of the debt discount, including the fair value of these warrants, is being amortized as interest expense over the remaining term of the Loan Agreement, as amended, using the effective interest method.
	The weighted average annual effective interest rate of the notes payable under the revised amortization schedule is 13.8%.
	Aggregate future minimum payments due under the Loan Agreement as of March 31, 2015 were as follows (in thousands):
	Year ending December 31,
	2015	$	459
	2016		7,153
	Total minimum payments		7,612
	Less amount representing interest		(793	)
	Notes payable, gross		6,819
	Unamortized discount on notes payable		(143	)
	Accretion of final payment		918
	Notes payable, balance		7,594
	Less current portion of notes payable		(713	)
	Non-current portion of notes payable	$	6,881

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ Equity
	Controlled Equity Offerings
	In August 2011, the Company entered into a Controlled Equity OfferingSM sales agreement (the “Sales Agreement”), with Cantor Fitzgerald & Co. (“Cantor”), as agent and/or principal, pursuant to which the Company could issue and sell shares of its common stock having an aggregate gross sales price of up to $20.0 million. In April 2013, the Sales Agreement was amended to provide for an increase of $30.0 million in the aggregate gross sales price under the Sales Agreement. In March 2015, the Sales Agreement was further amended to provide for an additional increase of $30.0 million in the aggregate gross sales price under the Sales Agreement. The Company will pay Cantor a commission of up to 3.0% of the gross proceeds from any common stock sold through the Sales Agreement, as amended.
	During the three months ended March 31, 2015, the Company sold 3,930,343 shares of common stock under the Sales Agreement, as amended, at an average price of approximately $2.62 per share for gross proceeds of $10.3 million and net proceeds of $10.0 million, after deducting Cantor’s commission. As of March 31, 2015, $26.5 million of common stock remained available to be sold under this facility, subject to certain conditions as specified in the Sales Agreement, as amended.
	In April 2015, the Company sold an aggregate of 2,834,035 shares of common stock under the Sales Agreement, as amended, at an average price of approximately $2.70 per share for gross proceeds of $7.6 million and net proceeds of $7.5 million, after deducting Cantor’s commission. As of April 30, 2015, $18.9 million of common stock remained available to be sold under this facility.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation
	Employee stock-based compensation expense is calculated based on the grant-date fair value of awards ultimately expected to vest, and is recorded on a straight-line basis over the vesting period of the awards. Forfeitures are estimated at the time of grant, based on historical option cancellation information, and revised in subsequent periods if actual forfeitures differ from those estimates.
	The following table summarizes stock-based compensation expense related to the Company’s stock-based awards for the periods indicated (in thousands):
		Three months ended
		March 31,
		2015		2014
	Research and development	$	699	$	459
	General and administrative		1,157		727
	Employee stock-based compensation expense		1,856		1,186
	Non-employee stock-based compensation expense		108		120
	Total stock-based compensation expense	$	1,964	$	1,306

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	10. Subsequent Events
	In April 2015, the Company sold an aggregate of 2,834,035 shares of common stock under the Sales Agreement, as amended, at an average price of approximately $2.70 per share for gross proceeds of $7.6 million and net proceeds of $7.5 million, after deducting Cantor’s commission. See Note 8 for further details.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. The financial statements include all adjustments (consisting only of normal recurring adjustments) that management believes are necessary for a fair presentation of the periods presented. The balance sheet as of December 31, 2014 was derived from the audited financial statements as of that date. These interim financial results are not necessarily indicative of results to be expected for the full year or any other period. These unaudited condensed consolidated financial statements and the notes accompanying them should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2014.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), that will supersede most existing revenue recognition guidance under US GAAP. The core principle of the guidance is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach. Entities electing the full retrospective adoption will apply the standard to each period presented in the financial statements. This means that entities will have to apply the new guidance as if it had been in effect since the inception of all its contracts with customers presented in the financial statements. Entities that elect the modified retrospective approach will apply the guidance retrospectively only to the most current period presented in the financial statements. This means that entities will have to recognize the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings at the date of initial application. The new revenue standard will be applied to contracts that are in progress at the date of initial application. As currently issued, the standard will be effective for annual and interim periods beginning after December 15, 2016. The Company has yet to evaluate which adoption method it plans to use or the potential effect of the new standard on its consolidated financial statements. On April 1, 2015, the FASB voted to propose to defer the effective date of the new revenue recognition standard by one year.
	In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern (“ASU 2014-15”), which will require a reporting entity to evaluate, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the reporting entity's ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. The standard will be effective for annual and interim periods beginning after December 15, 2016, with early adoption permitted. The Company has yet to evaluate the potential effect of the new standard on its consolidated financial statements.
Principles of Consolidation	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, Sunesis Europe Limited, a United Kingdom corporation, and Sunesis Pharmaceuticals (Bermuda) Ltd., a Bermuda corporation, as well as a Bermuda limited partnership, Sunesis Pharmaceuticals International LP. All intercompany balances and transactions have been eliminated in consolidation.
Segment Reporting	Segment Reporting
	Management has determined that the Company operates as a single reportable segment.
Significant Estimates and Judgments	Significant Estimates and Judgments
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s consolidated financial statements and accompanying notes thereto. Actual results could differ materially from these estimates. Estimates, assumptions and judgments made by management include those related to the valuation of equity and related instruments, revenue recognition, stock-based compensation and clinical trial accounting.
Cash Equivalents and Marketable Securities	Cash Equivalents and Marketable Securities
	Invoices for certain services provided to the Company are denominated in foreign currencies. To manage the risk of future movements in foreign exchange rates that would affect such amounts, the Company may purchase certain European currencies or highly-rated investments denominated in those currencies, subject to similar criteria as for other investments defined in the Company’s investment policy. There is no guarantee that the related gains and losses will substantially offset each other, and the Company may be subject to significant exchange gains or losses as currencies fluctuate from quarter to quarter. To date, the Company has purchased Euros and Euro-denominated obligations of foreign governments and corporate debt. As of March 31, 2015 and December 31, 2014, the Company held cash and investments denominated in Euros with an aggregate fair value of $0.7 million and $0, respectively. Any cash, cash equivalent and marketable securities balances denominated in foreign currencies are recorded at their fair value based on the current exchange rate as of each balance sheet date. The resulting exchange gains or losses and those from amounts payable for services originally denominated in foreign currencies are recorded in other income (expense), net in the statements of operations and comprehensive loss.
Fair Value Measurements	Fair Value Measurements
	The Company measures cash equivalents, marketable securities and warrant liabilities at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, in accordance with applicable GAAP:
	Level 1 - quoted prices (unadjusted) in active markets for identical assets and liabilities that can be accessed at the measurement date.
	Level 2 - inputs other than quoted prices included within Level 1 that are observable, either directly or indirectly.
	Level 3 - unobservable inputs.
	The Company’s Level 2 valuations of marketable securities are generally derived from independent pricing services based upon quoted prices in active markets for similar securities, with prices adjusted for yield and number of days to maturity, or based on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets.
	The fair value of the Company’s liability for warrants issued in connection with an underwritten offering completed in October 2010 (the “2010 Offering”) is determined using the Black-Scholes model, which requires inputs such as the expected term of the warrants, share price volatility, expected dividend yield and risk-free interest rate. As some of these inputs are unobservable, and require significant analysis and judgment to measure, these variables are classified as Level 3.
	The Company does not measure cash, prepayments, accounts payable, accrued liabilities, deferred revenue and notes payable at fair value, as their carrying amounts approximated their fair value as of March 31, 2015 and December 31, 2014.

Loss_per_Common_Share_Tables

Loss per Common Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Potential Common Shares Issuable Pursuant to Outstanding Securities Excluded from Computation of Diluted Loss per Common Share	The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted loss per common share because their inclusion would have had an anti-dilutive effect (in thousands):
		Three months ended
		March 31,
		2015		2014
	Warrants to purchase shares of common stock		11,898		19,171
	Options to purchase shares of common stock		10,649		9,287
	Outstanding securities not included in calculations		22,547		28,458

Financial_Instruments_Tables

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Company's Financial Assets Measured on Recurring Basis	The following tables summarize the estimated fair value of the Company’s financial assets measured on a recurring basis as of the dates indicated, which were comprised solely of available-for-sale marketable securities with remaining contractual maturities of one year or less (in thousands):
	31-Mar-15		Input Level		Amortized				Gross		Gross			Estimated Fair
					Cost				Unrealized		Unrealized			Value
									Gains		Losses
	Money market funds		Level 1		$	6,340			$	—	$	—		$	6,340
	U.S. certificates of deposit		Level 1			8,905				—		—			8,905
	U.S. corporate debt obligations		Level 2			10,356				—		(6	)		10,350
	U.S. commercial paper		Level 2			1,999				—		—			1,999
	Total available-for-sale securities					27,600				—		(6	)		27,594
	Less amounts classified as cash equivalents					(6,585	)			—		—			(6,585	)
	Amounts classified as marketable securities				$	21,015			$	—	$	(6	)	$	21,009
	31-Dec-14		Input Level		Amortized				Gross		Gross			Estimated Fair
					Cost				Unrealized		Unrealized			Value
									Gains		Losses
	Money market funds		Level 1		$	9,287			$	—	$	—		$	9,287
	U.S. certificates of deposit		Level 1		$	6,360				—		—		$	6,360
	U.S. corporate debt obligations		Level 2			11,789				—		(7	)		11,782
	U.S. commercial paper		Level 2			2,898				—		—			2,898
	Total available-for-sale securities					30,334				—		(7	)		30,327
	Less amounts classified as cash equivalents					(9,532	)			—		—			(9,532	)
	Amounts classified as marketable securities				$	20,802			$	—	$	(7	)	$	20,795
Summary of Available-for-Sale Securities in Unrealized Loss Position	The following table summarizes the available-for-sale securities that were in an unrealized loss position as of the date indicated, having been in such a position for less than 12 months, and none having been deemed to be other-than-temporarily impaired (in thousands):
	31-Mar-15		Gross				Estimated Fair
			Unrealized				Value
			Losses
	U.S. corporate debt obligations		$	6			$	8,896
Summary of Assumptions and Estimated Fair Value of Company's Financial Liabilities Measured on Recurring Basis	The following table summarizes the inputs and assumptions and estimated fair value of the Company’s financial liabilities measured on a recurring basis as of the dates indicated, which were comprised solely of a liability for warrants issued in connection with the 2010 Offering:
		March 31,				December 31,
		2015				2014
	Inputs and assumptions:
	Fair market value of Company’s common stock	$	2.45			$	2.55
	Exercise price	$	2.52			$	2.52
	Expected term (years)		0.5				0.8
	Expected volatility		193.4	%			144.9	%
	Risk-free interest rate		0.1	%			0.2	%
	Expected dividend yield		0	%			0	%
	Fair value:
	Estimated fair value per warrant share	$	1.24			$	1.21
	Shares underlying outstanding warrants classified as		2,920				2,920
	liabilities (in thousands)
	Total estimated fair value of outstanding warrants	$	3,632			$	3,543
	(in thousands)
Summary of Changes in Fair Value of Company's Level 3 Financial Liabilities	The following table summarizes the changes in the fair value of the Company’s Level 3 financial liabilities for the period indicated (in thousands):
		Warrant
		Liability
	Balance as of December 31, 2014	$	3,543
	Change in fair value of warrant liability		89
	Exercise of warrants		—
	Balance as of March 31, 2015	$	3,632

Notes_Payable_Tables

Notes Payable (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Summary of Future Minimum Payments Under Loan Agreement	Aggregate future minimum payments due under the Loan Agreement as of March 31, 2015 were as follows (in thousands):
	Year ending December 31,
	2015	$	459
	2016		7,153
	Total minimum payments		7,612
	Less amount representing interest		(793	)
	Notes payable, gross		6,819
	Unamortized discount on notes payable		(143	)
	Accretion of final payment		918
	Notes payable, balance		7,594
	Less current portion of notes payable		(713	)
	Non-current portion of notes payable	$	6,881

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-Based Compensation Expense Related to Company's Stock-Based Awards	The following table summarizes stock-based compensation expense related to the Company’s stock-based awards for the periods indicated (in thousands):
		Three months ended
		March 31,
		2015		2014
	Research and development	$	699	$	459
	General and administrative		1,157		727
	Employee stock-based compensation expense		1,856		1,186
	Non-employee stock-based compensation expense		108		120
	Total stock-based compensation expense	$	1,964	$	1,306

Company_Overview_Additional_In

Company Overview - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Date of incorporation	10-Feb-98
Cash, cash equivalents and marketable securities	$39,800,000
Accumulated deficit	$531,825,000	$522,697,000	[1]
Maturity limits period	24 months
Dollars weighted average maturity limit period	12 months
[1]	The condensed consolidated balance sheet as of December 31, 2014 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, 2014.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
	Segment
Accounting Policies [Abstract]
Number of reportable segment	1
Fair value of investments denominated in Euros	$0.70	$0

Loss_per_Common_Share_Schedule

Loss per Common Share - Schedule of Potential Common Shares Issuable Pursuant to Outstanding Securities Excluded from Computation of Diluted Loss per Common Share (Detail)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	22,547	28,458
Warrants to purchase shares of common stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	11,898	19,171
Options to purchase shares of common stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	10,649	9,287

Financial_Instruments_Fair_Val

Financial Instruments - Fair Value of Company's Financial Assets Measured on Recurring Basis (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	$27,600	$30,334
Available-for-sale securities, Gross Unrealized Losses	-6	-7
Available-for-sale securities, Estimated Fair Value	27,594	30,327
Less amounts classified as cash equivalents, Amortized Cost	-6,585	-9,532
Amounts classified as marketable securities, Amortized Cost	21,015	20,802
Amounts classified as marketable securities, Gross Unrealized Losses	-6	-7
Less amounts classified as cash equivalents, Estimated Fair Value	-6,585	-9,532
Amounts classified as marketable securities, Estimated Fair Value	21,009	20,795	[1]
Level 1 [Member] | Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	6,340	9,287
Available-for-sale securities, Estimated Fair Value	6,340	9,287
Level 1 [Member] | U.S. certificates of deposit [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	8,905	6,360
Available-for-sale securities, Estimated Fair Value	8,905	6,360
Level 2 [Member] | U.S. corporate debt obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	10,356	11,789
Available-for-sale securities, Gross Unrealized Losses	-6	-7
Available-for-sale securities, Estimated Fair Value	10,350	11,782
Level 2 [Member] | U.S. commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	1,999	2,898
Available-for-sale securities, Estimated Fair Value	$1,999	$2,898
[1]	The condensed consolidated balance sheet as of December 31, 2014 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, 2014.

Financial_Instruments_Summary_

Financial Instruments - Summary of Available-for-Sale Securities in Unrealized Loss Position (Detail) (U.S. corporate debt obligations [Member], USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
U.S. corporate debt obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Gross Unrealized Losses	$6
Estimated Fair Value	$8,896

Financial_Instruments_Addition

Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Sales of available-for-sale securities	$0	$0
2010 Offering [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants exercised for cash, shares	0

Financial_Instruments_Summary_1

Financial Instruments - Summary of Assumptions and Estimated Fair Value of Company's Financial Liabilities Measured on Recurring Basis (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Inputs and assumptions:
Fair market value of Company’s common stock	$2.45	$2.55
Exercise price	$2.52	$2.52
Expected term (years)	6 months	9 months 18 days
Expected volatility	193.40%	144.90%
Risk-free interest rate	0.10%	0.20%
Expected dividend yield	0.00%	0.00%
Fair value:
Estimated fair value per warrant share	$1.24	$1.21
Shares underlying outstanding warrants classified as liabilities (in thousands)	2,920	2,920
Total estimated fair value of outstanding warrants (in thousands)	$3,632	$3,543	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2014 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, 2014.

Financial_Instruments_Summary_2

Financial Instruments - Summary of Changes in Fair Value of Company's Level 3 Financial Liabilities (Detail) (Warrant Liability [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Warrant Liability [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Beginning Balance	$3,543
Change in fair value of warrant liability	89
Ending Balance	$3,632

Royalty_Agreement_Additional_I

Royalty Agreement - Additional Information (Detail) (USD $)	3 Months Ended	1 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2012
Royalty Agreement [Line Items]
Revenue participation right payments, rate	6.75%
Revenue participation right payments, term	10 years from the date of first commercial sale
Maximum term of revenue participation right payments	10 years
Royalty Agreement [Member]
Royalty Agreement [Line Items]
Revenue participation right payments		$25
Fair value of warrants issued in connection with participation agreement		$3.10

License_Agreements_Additional_

License Agreements - Additional Information (Detail) (USD $)	1 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Mar. 31, 2015	Jan. 31, 2014
License Agreement Terms [Member] | Millennium License Agreements [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Potential pre-commercialization milestone payments payable			$9.20
Potential pre-commercialization payments receivable		57.5
Biogen Idec [Member] | Development Events [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payment depending on development	$2.50

Notes_Payable_Additional_Infor

Notes Payable - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended
	Feb. 27, 2015	Mar. 31, 2015	Oct. 31, 2011	Oct. 18, 2011	Sep. 30, 2012	Sep. 19, 2012
	Loan	Installment
		Tranches
Debt Instrument [Line Items]
Maximum borrowing capacity			$25,000,000
Number of tranches for maximum borrowing		2
Number of installments		32
Line of credit facility final payment	1,162,500	937,500
Expiration date	1-Oct-16
Interest only period start date	1-Mar-15
Interest only period end date	1-Feb-16
Number of remaining principal payments	8
Prepayment penalty expiration date	29-Feb-16
Percentage of penalty for prepaying loan before maturity	2.00%
Warrants Expiration Term	5 years
Number of warrants issued	61,467
Warrants exercise price for shares	$2.22
Estimated fair value of warrants	100,000
Notes payable [Member]
Debt Instrument [Line Items]
Loan Agreement monthly arrears and interest date		1-Mar-13
Expiration date		1-Oct-15
Notes payable [Member] | Weighted Average [Member]
Debt Instrument [Line Items]
Weighted average annual effective interest rate on notes payable, including amortization of debt discounts and accretion	13.80%
Tranche one [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			10,000,000
Date of Loan and Security Agreement		31-Oct-11
Interest rate				8.95%
Tranche two [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity					$15,000,000
Line of credit facility remaining amount drawing date		30-Sep-12
Interest rate						9.00%

Notes_Payable_Summary_of_Futur

Notes Payable - Summary of Future Minimum Payments Under Loan Agreement (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Notes payable, balance	$7,594
Less current portion of notes payable	-713	-9,257	[1]
Non-current portion of notes payable	6,881
Notes payable [Member]
Debt Instrument [Line Items]
2015	459
2016	7,153
Total minimum payments	7,612
Less amount representing interest	-793
Notes payable, gross	6,819
Unamortized discount on notes payable	-143
Accretion of final payment	$918
[1]	The condensed consolidated balance sheet as of December 31, 2014 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, 2014.

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015	Aug. 31, 2011
Stockholders Equity [Line Items]
Proceeds from issuance of common stock through controlled equity offering facilities, net	$10,011,000	$4,726,000
Controlled Equity Offering Facilities [Member]
Stockholders Equity [Line Items]
Issuance of common stock, offering value				20,000,000
Common stock sales agreement, date	2011-08
Common stock sales agreement amended, date	2013-04
Issuance of common stock, remaining offering value	26,500,000
Controlled Equity Offering Facilities [Member] | Subsequent Event
Stockholders Equity [Line Items]
Issuance of common stock, remaining offering value			18,900,000
Controlled Equity Offering Facilities [Member] | Common Stock [Member]
Stockholders Equity [Line Items]
Common stock, shares sold	3,930,343
Price per common share	$2.62
Proceeds from issuance of common shares and warrants in offering, gross	10,300,000
Proceeds from issuance of common stock through controlled equity offering facilities, net	10,000,000
Controlled Equity Offering Facilities [Member] | Common Stock [Member] | Subsequent Event
Stockholders Equity [Line Items]
Common stock, shares sold			2,834,035
Price per common share			$2.70
Proceeds from issuance of common shares and warrants in offering, gross			7,600,000
Proceeds from issuance of common stock through controlled equity offering facilities, net			7,500,000
Additional Controlled Equity Offerings Facilities [Member]
Stockholders Equity [Line Items]
Increase in aggregate controlled equity offering agreement as per amendment	$30,000,000
Issuance of common stock, commission percentage	3.00%

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Stock-Based Compensation Expense Related to Company's Stock-Based Awards (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	$1,964	$1,306
Employee stock-based compensation expense [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	1,856	1,186
Non-employee stock-based compensation expense [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	108	120
Research and development [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	699	459
General and administrative [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	$1,157	$727

Subsequent_Events_Additional_i

Subsequent Events - Additional information (Detail) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015
Subsequent Event [Line Items]
Proceeds from issuance of common stock through controlled equity offering facilities, net	$10,011,000	$4,726,000
Controlled Equity Offering Facilities [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Common stock, shares sold	3,930,343
Price per common share	$2.62
Proceeds from issuance of common shares and warrants in offering, gross	10,300,000
Proceeds from issuance of common stock through controlled equity offering facilities, net	10,000,000
Subsequent Event | Controlled Equity Offering Facilities [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Common stock, shares sold			2,834,035
Price per common share			$2.70
Proceeds from issuance of common shares and warrants in offering, gross			7,600,000
Proceeds from issuance of common stock through controlled equity offering facilities, net			$7,500,000