Fresh Tracks Therapeutics (FRTX) 10-Q 1 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 15, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Trading Symbol	'VICL	'
Entity Registrant Name	'VICAL INC	'
Entity Central Index Key	'0000819050	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	88,604,220

Balance_Sheets

Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$31,793	$38,837
Marketable securities, available-for-sale	14,624	11,541
Restricted cash	3,119	3,119
Receivables and other assets	4,532	4,590
Total current assets	54,068	58,087
Long-term investments	1,994	1,980
Property and equipment, net	3,156	3,935
Intangible assets, net	1,994	1,972
Other assets	379	379
Total assets	61,591	66,353
Current liabilities:	'	'
Accounts payable and accrued expenses	3,716	3,503
Deferred revenue	75	150
Total current liabilities	3,791	3,653
Long-term liabilities:	'	'
Deferred rent	1,082	1,288
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Preferred stock, $0.01 par value, 5,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.01 par value, 160,000 shares authorized, 87,846 and 86,778 shares issued and outstanding at June 30, 2014, and December 31, 2013, respectively	878	868
Additional paid-in capital	442,489	439,708
Accumulated deficit	-386,670	-379,175
Accumulated other comprehensive income	21	11
Total stockholders' equity	56,718	61,412
Total liabilities and stockholders' equity	$61,591	$66,353

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, except Per Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	160,000	160,000
Common stock, shares issued	87,846	86,778
Common stock, shares outstanding	87,846	86,778

Statements_of_Operations

Statements of Operations (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:	'	'	'	'
Contract and grant revenue	$3,951	$1,170	$6,069	$2,306
License and royalty revenue	554	286	883	724
Total revenues	4,505	1,456	6,952	3,030
Operating expenses:	'	'	'	'
Research and development	2,379	3,930	4,525	7,580
Manufacturing and production	3,650	3,891	5,165	7,604
General and administrative	2,541	3,478	4,810	6,996
Total operating expenses	8,570	11,299	14,500	22,180
Loss from operations	-4,065	-9,843	-7,548	-19,150
Other income (expense):	'	'	'	'
Investment and other income (expense), net	25	-38	53	-13
Net loss	($4,040)	($9,881)	($7,495)	($19,163)
Basic and diluted net loss per share	($0.05)	($0.11)	($0.09)	($0.22)
Weighted average shares used in computing basic and diluted net loss per share	87,319	86,730	87,219	86,623

Statements_of_Comprehensive_Lo

Statements of Comprehensive Loss (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net loss	($4,040)	($9,881)	($7,495)	($19,163)
Unrealized gains (losses) on available-for-sale and long-term marketable securities:	'	'	'	'
Unrealized gains (losses) arising during holding period	27	-100	10	-113
Other comprehensive gain (loss)	27	-100	10	-113
Total comprehensive loss	($4,013)	($9,981)	($7,485)	($19,276)

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:	'	'
Net loss	($7,495)	($19,163)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	940	1,197
Write-off of abandoned patents	42	82
Compensation expense related to stock options and awards	1,721	1,954
Changes in operating assets and liabilities:	'	'
Receivables and other assets	59	69
Accounts payable and accrued expenses	182	325
Deferred revenue	-75	-75
Deferred rent	-174	-144
Net cash used in operating activities	-4,800	-15,755
Cash flows from investing activities:	'	'
Maturities of marketable securities	7,850	21,172
Purchases of marketable securities	-10,949	-3,037
Purchases of property and equipment	-27	-273
Patent expenditures	-188	-212
Net cash (used in) provided by investing activities	-3,314	17,650
Cash flows from financing activities:	'	'
Net proceeds from issuance of common stock	1,101	380
Payment of withholding taxes for net settlement of restricted stock units	-31	-401
Net cash provided by (used in) financing activities	1,070	-21
Net (decrease) increase in cash and cash equivalents	-7,044	1,874
Cash and cash equivalents at beginning of period	38,837	43,159
Cash and cash equivalents at end of period	$31,793	$45,033

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	1.       BASIS OF PRESENTATION
	Vical Incorporated, or the Company, a Delaware corporation, was incorporated in April 1987 and has devoted substantially all of its resources since that time to its research and development programs. The Company researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases.
	All of the Company’s potential products are in research and development phases. No revenues have been generated from the sale of any such products, nor are any such revenues expected for at least the next several years. The Company earns revenue from research and development agreements with pharmaceutical collaborators and grant and contract arrangements with government entities. Most of the Company’s product candidates will require significant additional research and development efforts, including extensive preclinical and clinical testing. All product candidates that advance to clinical testing will require regulatory approval prior to commercial use, and will require significant costs for commercialization. There can be no assurance that the Company’s research and development efforts, or those of its collaborators, will be successful. The Company expects to continue to incur substantial losses and not generate positive cash flows from operations for at least the next several years. No assurance can be given that the Company can generate sufficient product revenue to become profitable or generate positive cash flows from operations.
	The unaudited financial statements at June 30, 2014, and for the three and six months ended June 30, 2014 and 2013, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission, or SEC, and with accounting principles generally accepted in the United States applicable to interim financial statements. These unaudited financial statements have been prepared on the same basis as the audited financial statements included in the Company’s Annual Report on Form 10-K and include all adjustments, consisting of only normal recurring accruals, which in the opinion of management are necessary to present fairly the Company’s financial position as of the interim date and results of operations for the interim periods presented. Interim results are not necessarily indicative of results expected for a full year or future periods. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates. These unaudited financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2013, included in its Annual Report on Form 10-K filed with the SEC.
	The accompanying cash flow statement for the six months ended June 30, 2013 contains a reclassification of certain amortization expenses from investing activities to operating activities to conform to the current year presentation.
	Cash, Cash Equivalents and Marketable Securities
	Cash and cash equivalents consist of cash and highly liquid securities with original maturities at the date of acquisition of 90 days or less. Investments with an original maturity of more than 90 days are considered marketable securities and have been classified by management as available-for-sale. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Such investments are carried at fair value, with unrealized gains and losses included as a separate component of stockholders’ equity. Realized gains and losses from the sale of available-for-sale securities or the amounts, net of tax, reclassified out of accumulated other comprehensive income, if any, are determined on a specific identification basis.
	Restricted Cash
	The Company is required to maintain a letter of credit securing an amount equal to twelve months of the current monthly installment of base rent for the term of its primary facilities lease, which ends in August 2017. Under certain circumstances, the Company may be able to eliminate the need for the letter of credit. As of June 30, 2014, and December 31, 2013, restricted cash of $3.1 million was pledged as collateral for this letter of credit.
	Revenue Recognition
	Revenue is recognized when the four basic criteria of revenue recognition are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services rendered; (3) the fee is fixed or determinable; and (4) collectability is reasonably assured. Certain of the Company’s revenue is generated through manufacturing contracts and stand-alone license agreements.
	The Company has entered into multiple-element arrangements. In order to account for the multiple-element arrangements, the Company identifies the deliverables included within the agreement and evaluates which deliverables represent separate units of accounting. Analyzing the arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver services, a right or license to use an asset, or another performance obligation.
	The delivered item(s) must have value to the customer on a standalone basis and, if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item(s) is considered probable and substantially in the Company’s control.
	A delivered item is considered a separate unit of accounting when the delivered item has value to the partner on a standalone basis based on the consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research capabilities of the partner and the availability of research expertise in this field in the general marketplace. Arrangement consideration is allocated at the inception of the agreement to all identified units of accounting based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence, or VSOE, of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence of selling price exists, the Company uses its best estimate of the selling price for the deliverable. The amount of allocable arrangement consideration is limited to amounts that are fixed or determinable. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units. Changes in the allocation of the sales price between delivered and undelivered elements can impact revenue recognition but do not change the total revenue recognized under any agreement. If facts and circumstances dictate that the license has standalone value from the undelivered items, which generally include research and development services and the manufacture of drug products, the license is identified as a separate unit of accounting and the amounts allocated to the license are recognized upon the delivery of the license, assuming the other revenue recognition criteria have been met. However, if the amounts allocated to the license through the relative selling price allocation exceed the upfront license fee, the amount recognized upon the delivery of the license is limited to the upfront fee received. If facts and circumstances dictate that the license does not have standalone value, the transaction price, including any upfront license fee payments received, are allocated to the identified separate units of accounting and recognized as those items are delivered.
	The terms of the Company’s license and collaboration agreements provide for milestone payments upon achievement of certain regulatory and commercial events. The Company 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 substantive in its entirety. A milestone is considered substantive when it meets all of the following three criteria: (1) the consideration is commensurate with either the entity’s performance to achieve the milestone or 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, (2) the consideration relates solely to past performance, and (3) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. A milestone is defined as an event (i) that can only be achieved based in whole or in part on either the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved and (iii) that would result in additional payments being due to the Company.
	Contract Services, Grant and Royalty Revenue
	The Company recognizes revenues from contract services and federal government research grants during the period in which the related expenditures are incurred and related payments for those services are received or collection is reasonably assured. Royalties to be received based on sales of licensed products by the Company’s partners incorporating the Company’s licensed technology are recognized when received.
	Manufacturing and Production Costs
	Manufacturing and production costs include expenses related to manufacturing contracts and expenses for the production of plasmid DNA for use in the Company’s research and development efforts. Manufacturing expenses related to manufacturing contracts are deferred and expensed when the related revenue is recognized. Production expenses related to the Company’s research and development efforts are expensed as incurred.
	Net Loss Per Share
	Basic and diluted net loss per share has been computed using the weighted-average number of shares of common stock outstanding during the period. The weighted average number of shares used to compute diluted net loss per share excludes any assumed exercise of stock options and warrants, and any assumed issuance of common stock under restricted stock units as the effect would be antidilutive. Common stock equivalents of 0.4 million and 1.4 million for the three months ended June 30, 2014 and 2013, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 0.5 million and 1.5 million for the six months ended June 30, 2014 and 2013, respectively, were excluded from the calculation because of their antidilutive effect.
	Stock-Based Compensation
	The Company records its compensation expense associated with stock options and other share-based awards in accordance with the authoritative guidance for stock-based compensation. The cost of employee services received in exchange for an award of an equity instrument is measured at the grant date using the Black-Scholes-Merton option pricing model. Stock-based compensation includes amortization related to stock option awards based on the estimated grant date fair value. Stock-based compensation expense related to stock options includes an estimate for forfeitures and the portion that is ultimately expected to vest is recognized ratably over the vesting period of the option. In addition, the Company records expense related to restricted stock units, or RSUs, granted based on the fair value of those awards on the grant date. The fair value related to the RSUs is amortized to expense over the vesting term of those awards. Stock-based compensation expense related to RSUs includes an estimate for forfeitures and the portion expected to vest is recognized over the expected term of the award using the straight-line method. Stock-based compensation expense for a stock-based award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized and any recognized compensation expense is reversed.
	Recent Accounting Pronouncement
	In May 2014, the FASB issued guidance that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The guidance provides that an entity recognize revenue when it transfers 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 guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. The guidance allows for either full retrospective or modified retrospective adoption and will become effective for the Company in the first quarter of 2017. The Company is evaluating the alternative transition methods and the potential effects of the adoption of this update on its financial statements.
	In July 2013, the FASB issued guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of this standard during the first quarter of 2014 did not have a material impact on the Company’s consolidated financial statements.

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-Based Compensation	'
	2.       STOCK-BASED COMPENSATION
	Total stock-based compensation expense was allocated to research and development, manufacturing and production and general and administrative expense as follows (in thousands):
		Three Months Ended				Six Months Ended
		June  30,				June 30,
		2014		2013		2014		2013
	Research and development	$	233	$	242	$	442	$	554
	Manufacturing and production		76		60		121		128
	General and administrative		575		514		1,158		1,272
	Total stock-based compensation expense	$	884	$	816	$	1,721	$	1,954
	During the six months ended June 30, 2014 and 2013, the Company granted stock-based awards with a total estimated value of $2.3 million and $3.8 million, respectively. At June 30, 2014, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $3.1 million, which is expected to be recognized over a weighted-average period of 1.3 years. Stock-based awards granted during the six months ended June 30, 2014 and 2013, were equal to 3.1% and 2.2%, respectively, of the outstanding shares of common stock at the end of the applicable period.

Marketable_Securities_Availabl

Marketable Securities, Available for Sale	6 Months Ended
	Jun. 30, 2014
Investments Debt And Equity Securities [Abstract]	'
Marketable Securities, Available for Sale	'
	3.       MARKETABLE SECURITIES, AVAILABLE FOR SALE
	The following is a summary of available-for-sale marketable securities (in thousands):
	June 30, 2014	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	3,560	$	2	$	—	$	3,562
	Government-sponsored enterprise securities		6,998		—		4		6,994
	Corporate bonds		—		—		—		—
	Certificates of deposit		4,068		—		—		4,068
		$	14,626	$	2	$	4	$	14,624
	December 31, 2013	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	1,500	$	3	$	—	$	1,503
	Government-sponsored enterprise securities		4,500		—		—		4,500
	Corporate bonds		4,853		—		—		4,853
	Certificates of deposit		685		—		—		685
		$	11,538	$	3	$	—	$	11,541
	At June 30, 2014, $9.1 million of these securities were scheduled to mature outside of one year. The Company did not realize any gains or losses on sales of available-for-sale securities for the six months ended June 30, 2014. As of June 30, 2014, none of the securities had been in a continuous material unrealized loss position longer than one year.

Other_Balance_Sheet_Accounts

Other Balance Sheet Accounts	6 Months Ended
	Jun. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Other Balance Sheet Accounts	'
	4.       OTHER BALANCE SHEET ACCOUNTS
	Accounts payable and accrued expenses consisted of the following (in thousands):
		June 30,		December 31,
		2014		2013
	Employee compensation	$	1,587	$	1,587
	Post-termination benefit accrual		55		369
	Clinical trial accrual		567		347
	Accounts payable		669		395
	Deferred rent		400		369
	Other accrued liabilities		438		436
	Total accounts payable and accrued expenses	$	3,716	$	3,503

LongTerm_Investments

Long-Term Investments	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Long-Term Investments	'
	5.       LONG-TERM INVESTMENTS
	As of June 30, 2014, the Company held an auction rate security with a par value of $2.5 million. This auction rate security has not experienced a successful auction since the liquidity issues experienced in the global credit and capital markets in 2008. As a result, the security is classified as a long-term investment as it is scheduled to mature in 2038. The security was rated A- by Standard and Poor’s as of June 30, 2014. The security continues to pay interest according to its stated terms.
	The valuation of the Company’s auction rate security is subject to uncertainties that are difficult to predict. The fair value of the security is estimated by management utilizing a discounted cash flow analysis. The key drivers of the valuation model include the expected term, collateralization underlying the security investment, the creditworthiness of the counterparty, the timing of expected future cash flows, discount rates, liquidity and the expected holding period. The security was also compared, when possible, to other observable market data for securities with similar characteristics. Based on the valuation of the security, the Company has recognized cumulative losses of $0.5 million, net of tax, as of June 30, 2014. The losses when recognized are included in investment and other income. The market value of the security has partially recovered. Included in other comprehensive gain (loss) are unrealized gains (losses) of $14,000 and $(113,000) for the six months ended June 30, 2014 and 2013, respectively. As of June 30, 2014, the Company had recorded cumulative unrealized gains of $0.2 million. The resulting carrying value of the auction rate security at June 30, 2014, was $2.0 million. Any future decline in market value may result in additional losses being recognized.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	6.       FAIR VALUE MEASUREMENTS
	The Company measures fair value as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. Fair value measurements are based on a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:
		•		Level 1: Observable inputs such as quoted prices in active markets;
		•		Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and
		•		Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.
	Cash equivalents, marketable securities and long-term investments measured at fair value are classified in the table below in one of the three categories described above (in thousands):
			Fair Value Measurements
	June 30, 2014		Level 1		Level 2		Level 3		Total
	Certificates of deposit		$	4,068	$	—	$	—	$	4,068
	Money market funds			169		—		—		169
	U.S. treasuries			3,562		—		—		3,562
	Government-sponsored enterprise securities			—		6,994		—		6,994
	Auction rate securities			—		—		1,994		1,994
			$	7,799	$	6,994	$	1,994	$	16,787
			Fair Value Measurements
	December 31, 2013		Level 1		Level 2		Level 3		Total
	Certificates of deposit		$	685	$	—	$	—	$	685
	Money market funds			2,275		—		—		2,275
	U.S. treasuries			1,503		—		—		1,503
	Corporate bonds			—		4,853		—		4,853
	Government-sponsored enterprise securities			—		4,500		—		4,500
	Auction rate securities			—		—		1,980		1,980
			$	4,463	$	9,353	$	1,980	$	15,796
	The Company’s investments in U.S. treasury securities, certificates of deposit and money market funds are valued based on publicly available quoted market prices for identical securities as of June 30, 2014. The Company determines the fair value of corporate bonds and other government-sponsored enterprise related securities with the aid of valuations provided by third parties using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. The Company validates the valuations received from its primary pricing vendors for its level 2 securities by examining the inputs used in that vendor’s pricing process and determines whether they are reasonable and observable. The Company also compares those valuations to recent reported trades for those securities. The Company did not adjust any of the valuations received from these independent third parties with respect to any of its level 2 securities at June 30, 2014. The Company did not transfer any investments between level categories during the six months ended June 30, 2014. The valuation of the Company’s investments in auction rate securities, which includes significant unobservable inputs, is more fully described in Note 5.
	Activity for assets measured at fair value using significant unobservable inputs (Level 3) is presented in the table below (in thousands):
			Six Months
			Ended
			June  30, 2014
	Balance at December 31, 2013		$	1,980
	Total net unrealized gains, excluding tax impact, included in other comprehensive loss			14
	Balance at June 30, 2014		$	1,994
	Total gains or losses for the period included in net loss attributable to the change in unrealized gains or losses relating to assets still held at the reporting date		$	—

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	7.       COMMITMENTS AND CONTINGENCIES
	In late October and early November 2013, following the Company’s announcement of the results of its Phase 3 trial of Allovectin® and the subsequent decline of the price of its common stock, two putative, securities class action complaints were filed in the U.S. District Court for the Southern District of California against the Company and certain of its current and former officers. On February 26, 2014, the two cases were consolidated into one action and a lead plaintiff and lead counsel were appointed. On April 3, 2014, the lead plaintiff filed a consolidated complaint alleging that the defendants violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 by making materially false and misleading statements regarding the Company’s business prospects and the prospects for Allovectin®, thereby artificially inflating the price of the Company’s common stock. The consolidated complaint seeks unspecified monetary damages and other relief. On April 25, 2014, the parties filed a joint motion asking the Court to permit plaintiffs to amend the consolidated complaint, which the Court granted. On May 12, 2014, lead plaintiff filed an amended complaint. On June 9, 2014, defendants filed a motion to dismiss the amended complaint. That same day, defendants also filed a motion to strike certain allegations in the amended complaint. The motion to strike is fully briefed, but the Court has not yet issued an order. Lead plaintiff’s deadline to oppose defendants’ pending motion to dismiss is August 4, 2014. A hearing, if any, on the motion to dismiss is currently scheduled for August 25, 2014. The Company plans to vigorously defend against the claims advanced. At this time, the Company is unable to estimate possible losses or ranges of losses for ongoing legal actions.
	In the ordinary course of business, the Company may become a party to additional lawsuits involving various matters. The Company is unaware of any such lawsuits presently pending against it which, individually or in the aggregate, are deemed to be material to the Company’s financial condition or results of operations.
	The Company prosecutes its intellectual property vigorously to obtain the broadest valid scope for its patents. Due to uncertainty of the ultimate outcome of these matters, the impact on future operating results or the Company’s financial condition is not subject to reasonable estimates.

Astellas_Agreements

Astellas Agreements	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Astellas Agreements	'
	8.       ASTELLAS AGREEMENTS
	In July 2011, the Company entered into license agreements with Astellas Pharma Inc., or Astellas, granting Astellas exclusive, worldwide, royalty-bearing licenses under certain of the Company’s know-how and intellectual property to develop and commercialize certain products containing plasmids encoding certain forms of cytomegalovirus, glycoprotein B and/or phosphoprotein 65, including ASP0113 (TransVax™) but excluding CyMVectin™.
	Under the terms of the license agreements, Astellas paid a nonrefundable upfront license fee of $25.0 million in 2011. The Company also received a $10.0 million milestone payment in March 2012 upon finalization of the general trial design for a Phase 3 registration trial of ASP0113 in hematopoietic stem cell transplant recipients. The Company recognized $0.7 million and $0.3 million in license revenue under the Astellas agreements during the six months ended June 30, 2014 and 2013, respectively.
	Under the terms of the agreements, the Company is also performing research and development services and manufacturing services which are being paid for by Astellas. During the three and six months ended June 30, 2014, the Company recognized $4.0 million and $6.1 million, respectively, of revenue related to these contract services. During the three and six months ended June 30, 2013, the Company recognized $1.1 million and $2.2 million, respectively, of revenue related to these contract services.
	In August 2012, the Company amended its license and supply agreements with Astellas to, among other things, extend the time period that the Company is obligated to supply licensed products for commercial use to Astellas, at Astellas’ expense, modify the allocation of $95.0 million of milestone payments among certain milestones through commercial launch and modify the structure of the royalties on net sales from a fixed double digit royalty to tiered double digit royalties.

Restructuring_Costs

Restructuring Costs	6 Months Ended
	Jun. 30, 2014
Restructuring And Related Activities [Abstract]	'
Restructuring Costs	'
	9.       RESTRUCTURING COSTS
	In August 2013, the Company announced that its Phase 3 clinical trial of Allovectin®, the Company’s investigational cancer immunotherapy, failed to meet the pre-established endpoints. As a result, the Company restructured its operations to conserve capital, which included a staff reduction of 47 employees and the write-off of certain intangible assets. The Company recorded charges for employee termination benefits of $2.2 million and for asset impairments of $0.7 million in August of 2013.
	The following table sets forth activity in the restructuring liability for the six months ended June 30, 2014, which is wholly comprised of employee severance costs (in thousands):
		Accrued
		Severance
	Balance at December 31, 2013	$	281
	Accruals		—
	Payments	$	(226	)
	Balance at June 30, 2014	$	55
	The balance of the accrued severance liability at June 30, 2014 is anticipated to be fully distributed by September 30, 2014.

Stockholders_Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Stockholders' Equity	'
	10.      STOCKHOLDERS’ EQUITY
	In April 2014, the Company entered into an At-The-Market Issuance Sales Agreement, or Sales Agreement, with Meyers Associates, L.P. (doing business as Brinson Patrick, a division of Meyers Associates, L.P.), or Brinson Patrick, under which the Company may issue and sell up to $25,000,000 of shares of its common stock from time to time. Under the Sales Agreement, the Company may deliver placement notices that will set the parameters for the sale of shares, including the number of shares to be issued, the time period during which sales are requested to be made, any limitation on the number of shares that may be sold in any one trading day and any minimum price below which sales may not be made. Subject to the terms and conditions of the Sales Agreement, Brinson Patrick may sell the shares only by methods deemed to be an “at the market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including without limitation sales made directly through the Nasdaq Global Market, on any other existing trading market for the Company’s common stock or to or through a market maker. The Sales Agreement may be terminated by the Company upon prior notice to Brinson Patrick or by Brinson Patrick upon prior notice to the Company, or at any time under certain circumstances, including but not limited to the occurrence of a material adverse effect on the Company. During the three months ended June 30, 2014, the Company sold 982,016 shares under the sales agreement and received gross proceeds of $1,172,682.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Cash, Cash Equivalents and Marketable Securities	'
	Cash, Cash Equivalents and Marketable Securities
	Cash and cash equivalents consist of cash and highly liquid securities with original maturities at the date of acquisition of 90 days or less. Investments with an original maturity of more than 90 days are considered marketable securities and have been classified by management as available-for-sale. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Such investments are carried at fair value, with unrealized gains and losses included as a separate component of stockholders’ equity. Realized gains and losses from the sale of available-for-sale securities or the amounts, net of tax, reclassified out of accumulated other comprehensive income, if any, are determined on a specific identification basis.
Restricted Cash	'
	Restricted Cash
	The Company is required to maintain a letter of credit securing an amount equal to twelve months of the current monthly installment of base rent for the term of its primary facilities lease, which ends in August 2017. Under certain circumstances, the Company may be able to eliminate the need for the letter of credit. As of June 30, 2014, and December 31, 2013, restricted cash of $3.1 million was pledged as collateral for this letter of credit.
Revenue Recognition	'
	Revenue Recognition
	Revenue is recognized when the four basic criteria of revenue recognition are met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services rendered; (3) the fee is fixed or determinable; and (4) collectability is reasonably assured. Certain of the Company’s revenue is generated through manufacturing contracts and stand-alone license agreements.
	The Company has entered into multiple-element arrangements. In order to account for the multiple-element arrangements, the Company identifies the deliverables included within the agreement and evaluates which deliverables represent separate units of accounting. Analyzing the arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver services, a right or license to use an asset, or another performance obligation.
	The delivered item(s) must have value to the customer on a standalone basis and, if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item(s) is considered probable and substantially in the Company’s control.
	A delivered item is considered a separate unit of accounting when the delivered item has value to the partner on a standalone basis based on the consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research capabilities of the partner and the availability of research expertise in this field in the general marketplace. Arrangement consideration is allocated at the inception of the agreement to all identified units of accounting based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence, or VSOE, of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence of selling price exists, the Company uses its best estimate of the selling price for the deliverable. The amount of allocable arrangement consideration is limited to amounts that are fixed or determinable. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units. Changes in the allocation of the sales price between delivered and undelivered elements can impact revenue recognition but do not change the total revenue recognized under any agreement. If facts and circumstances dictate that the license has standalone value from the undelivered items, which generally include research and development services and the manufacture of drug products, the license is identified as a separate unit of accounting and the amounts allocated to the license are recognized upon the delivery of the license, assuming the other revenue recognition criteria have been met. However, if the amounts allocated to the license through the relative selling price allocation exceed the upfront license fee, the amount recognized upon the delivery of the license is limited to the upfront fee received. If facts and circumstances dictate that the license does not have standalone value, the transaction price, including any upfront license fee payments received, are allocated to the identified separate units of accounting and recognized as those items are delivered.
	The terms of the Company’s license and collaboration agreements provide for milestone payments upon achievement of certain regulatory and commercial events. The Company 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 substantive in its entirety. A milestone is considered substantive when it meets all of the following three criteria: (1) the consideration is commensurate with either the entity’s performance to achieve the milestone or 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, (2) the consideration relates solely to past performance, and (3) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. A milestone is defined as an event (i) that can only be achieved based in whole or in part on either the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved and (iii) that would result in additional payments being due to the Company.
Contract Services, Grant and Royalty Revenue	'
	Contract Services, Grant and Royalty Revenue
	The Company recognizes revenues from contract services and federal government research grants during the period in which the related expenditures are incurred and related payments for those services are received or collection is reasonably assured. Royalties to be received based on sales of licensed products by the Company’s partners incorporating the Company’s licensed technology are recognized when received.
Manufacturing and Production Costs	'
	Manufacturing and Production Costs
	Manufacturing and production costs include expenses related to manufacturing contracts and expenses for the production of plasmid DNA for use in the Company’s research and development efforts. Manufacturing expenses related to manufacturing contracts are deferred and expensed when the related revenue is recognized. Production expenses related to the Company’s research and development efforts are expensed as incurred.
Net Loss Per Share	'
	Net Loss Per Share
	Basic and diluted net loss per share has been computed using the weighted-average number of shares of common stock outstanding during the period. The weighted average number of shares used to compute diluted net loss per share excludes any assumed exercise of stock options and warrants, and any assumed issuance of common stock under restricted stock units as the effect would be antidilutive. Common stock equivalents of 0.4 million and 1.4 million for the three months ended June 30, 2014 and 2013, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 0.5 million and 1.5 million for the six months ended June 30, 2014 and 2013, respectively, were excluded from the calculation because of their antidilutive effect.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company records its compensation expense associated with stock options and other share-based awards in accordance with the authoritative guidance for stock-based compensation. The cost of employee services received in exchange for an award of an equity instrument is measured at the grant date using the Black-Scholes-Merton option pricing model. Stock-based compensation includes amortization related to stock option awards based on the estimated grant date fair value. Stock-based compensation expense related to stock options includes an estimate for forfeitures and the portion that is ultimately expected to vest is recognized ratably over the vesting period of the option. In addition, the Company records expense related to restricted stock units, or RSUs, granted based on the fair value of those awards on the grant date. The fair value related to the RSUs is amortized to expense over the vesting term of those awards. Stock-based compensation expense related to RSUs includes an estimate for forfeitures and the portion expected to vest is recognized over the expected term of the award using the straight-line method. Stock-based compensation expense for a stock-based award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized and any recognized compensation expense is reversed.
Recent Accounting Pronouncement	'
	Recent Accounting Pronouncement
	In May 2014, the FASB issued guidance that outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The guidance provides that an entity recognize revenue when it transfers 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 guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. The guidance allows for either full retrospective or modified retrospective adoption and will become effective for the Company in the first quarter of 2017. The Company is evaluating the alternative transition methods and the potential effects of the adoption of this update on its financial statements.
	In July 2013, the FASB issued guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of this standard during the first quarter of 2014 did not have a material impact on the Company’s consolidated financial statements.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Total Stock-Based Compensation Expense	'
	Total stock-based compensation expense was allocated to research and development, manufacturing and production and general and administrative expense as follows (in thousands):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2014		2013		2014		2013
	Research and development	$	233	$	242	$	442	$	554
	Manufacturing and production		76		60		121		128
	General and administrative		575		514		1,158		1,272
	Total stock-based compensation expense	$	884	$	816	$	1,721	$	1,954

Marketable_Securities_Availabl1

Marketable Securities, Available for Sale (Tables)	6 Months Ended
	Jun. 30, 2014
Investments Debt And Equity Securities [Abstract]	'
Summary of Available-for-Sale Marketable Securities	'
	The following is a summary of available-for-sale marketable securities (in thousands):
	June 30, 2014	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	3,560	$	2	$	—	$	3,562
	Government-sponsored enterprise securities		6,998		—		4		6,994
	Corporate bonds		—		—		—		—
	Certificates of deposit		4,068		—		—		4,068
		$	14,626	$	2	$	4	$	14,624
	December 31, 2013	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	1,500	$	3	$	—	$	1,503
	Government-sponsored enterprise securities		4,500		—		—		4,500
	Corporate bonds		4,853		—		—		4,853
	Certificates of deposit		685		—		—		685
		$	11,538	$	3	$	—	$	11,541

Other_Balance_Sheet_Accounts_T

Other Balance Sheet Accounts (Tables)	6 Months Ended
	Jun. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Summary of Accounts Payable and Accrued Expenses	'
	Accounts payable and accrued expenses consisted of the following (in thousands):
		June 30,		December 31,
		2014		2013
	Employee compensation	$	1,587	$	1,587
	Post-termination benefit accrual		55		369
	Clinical trial accrual		567		347
	Accounts payable		669		395
	Deferred rent		400		369
	Other accrued liabilities		438		436
	Total accounts payable and accrued expenses	$	3,716	$	3,503

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Summary of Cash Equivalents, Marketable Securities and Long-Term Investments Measured at Fair Value	'
	Cash equivalents, marketable securities and long-term investments measured at fair value are classified in the table below in one of the three categories described above (in thousands):
		Fair Value Measurements
	June 30, 2014	Level 1		Level 2		Level 3		Total
	Certificates of deposit	$	4,068	$	—	$	—	$	4,068
	Money market funds		169		—		—		169
	U.S. treasuries		3,562		—		—		3,562
	Government-sponsored enterprise securities		—		6,994		—		6,994
	Auction rate securities		—		—		1,994		1,994
		$	7,799	$	6,994	$	1,994	$	16,787
		Fair Value Measurements
	December 31, 2013	Level 1		Level 2		Level 3		Total
	Certificates of deposit	$	685	$	—	$	—	$	685
	Money market funds		2,275		—		—		2,275
	U.S. treasuries		1,503		—		—		1,503
	Corporate bonds		—		4,853		—		4,853
	Government-sponsored enterprise securities		—		4,500		—		4,500
	Auction rate securities		—		—		1,980		1,980
		$	4,463	$	9,353	$	1,980	$	15,796
Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs	'
	Activity for assets measured at fair value using significant unobservable inputs (Level 3) is presented in the table below (in thousands):
		Six Months
		Ended
		June  30, 2014
	Balance at December 31, 2013	$	1,980
	Total net unrealized gains, excluding tax impact, included in other comprehensive loss		14
	Balance at June 30, 2014	$	1,994
	Total gains or losses for the period included in net loss attributable to the change in unrealized gains or losses relating to assets still held at the reporting date	$	—

Restructuring_Costs_Tables

Restructuring Costs (Tables)	6 Months Ended
	Jun. 30, 2014
Restructuring And Related Activities [Abstract]	'
Schedule of Restructuring Liability	'
	The following table sets forth activity in the restructuring liability for the six months ended June 30, 2014, which is wholly comprised of employee severance costs (in thousands):
		Accrued
		Severance
	Balance at December 31, 2013	$	281
	Accruals		—
	Payments	$	(226	)
	Balance at June 30, 2014	$	55

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'	'	'	'	'
Maximum period for cash and highly liquid securities with original maturities	'	'	'90 days or less	'	'
Minimum period for marketable securities classified as available-for-sale with original maturities	'	'	'More than 90 days	'	'
Amount of letter of credit, description	'	'	'The Company is required to maintain a letter of credit securing an amount equal to twelve months of the current monthly installment of base rent for the term of its primary facilities lease, which ends in August 2017.	'	'
Restricted cash	$3,119	'	$3,119	'	$3,119
Common stock equivalents excluded from the calculation of diluted net loss per share	0.4	1.4	0.5	1.5	'

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Total Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	$884	$816	$1,721	$1,954
Research and development [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	233	242	442	554
Manufacturing and production [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	76	60	121	128
General and administrative [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total stock-based compensation expense	$575	$514	$1,158	$1,272

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'
Estimated value of stock-based awards, granted	$2.30	$3.80
Unrecognized compensation cost related to unvested options	$3.10	'
Unvested stock-based awards expected to be recognized, weighted-average period	'1 year 3 months 18 days	'
Portion of stock-based awards granted from outstanding common shares	3.10%	2.20%

Marketable_Securities_Availabl2

Marketable Securities, Available for Sale - Summary of Available-for-Sale Marketable Securities (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$14,626	$11,538
Unrealized Gain	2	3
Unrealized Loss	4	0
Market Value	14,624	11,541
U.S. treasuries [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	3,560	1,500
Unrealized Gain	2	3
Unrealized Loss	0	0
Market Value	3,562	1,503
Government-sponsored enterprise securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	6,998	4,500
Unrealized Gain	0	0
Unrealized Loss	4	0
Market Value	6,994	4,500
Corporate bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	0	4,853
Unrealized Gain	0	0
Unrealized Loss	0	0
Market Value	0	4,853
Certificates of deposit [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	4,068	685
Unrealized Gain	0	0
Unrealized Loss	0	0
Market Value	$4,068	$685

Marketable_Securities_Availabl3

Marketable Securities, Available for Sale - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
Investments Debt And Equity Securities [Abstract]	'
Available-for-sale securities maturing outside of one year	$9,100,000
Realized gains or losses on sales of available-for-sale securities	0
Available-for-sale securities in a continuous material unrealized loss position longer than one year	$0

Other_Balance_Sheet_Accounts_S

Other Balance Sheet Accounts - Summary of Accounts Payable and Accrued Expenses (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]	'	'
Employee compensation	$1,587	$1,587
Post-termination benefit accrual	55	369
Clinical trial accrual	567	347
Accounts payable	669	395
Deferred rent	400	369
Other accrued liabilities	438	436
Total accounts payable and accrued expenses	$3,716	$3,503

LongTerm_Investments_Additiona

Long-Term Investments - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Investments Schedule [Abstract]	'	'
Auction rate securities held, at par value	$2,500,000	'
Maturity of long-term investment	'2038	'
Recognized cumulative losses	500,000	'
Unrealized losses on auction rate securities	14,000	-113,000
Cumulative unrealized gains	200,000	'
Carrying value of auction rate security	$2,000,000	'

Fair_Value_Measurements_Summar

Fair Value Measurements - Summary of Cash Equivalents, Marketable Securities and Long-Term Investments Measured at Fair Value (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	$16,787	$15,796
Certificates of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	4,068	685
Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	169	2,275
U.S. treasuries [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	3,562	1,503
Corporate bonds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	'	4,853
Government-sponsored enterprise securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	6,994	4,500
Auction rate securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	1,994	1,980
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	7,799	4,463
Level 1 [Member] | Certificates of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	4,068	685
Level 1 [Member] | Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	169	2,275
Level 1 [Member] | U.S. treasuries [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	3,562	1,503
Level 1 [Member] | Corporate bonds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	'	0
Level 1 [Member] | Government-sponsored enterprise securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 1 [Member] | Auction rate securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	6,994	9,353
Level 2 [Member] | Certificates of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 2 [Member] | Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 2 [Member] | U.S. treasuries [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 2 [Member] | Corporate bonds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	'	4,853
Level 2 [Member] | Government-sponsored enterprise securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	6,994	4,500
Level 2 [Member] | Auction rate securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	1,994	1,980
Level 3 [Member] | Certificates of deposit [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 3 [Member] | Money market funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 3 [Member] | U.S. treasuries [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 3 [Member] | Corporate bonds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	'	0
Level 3 [Member] | Government-sponsored enterprise securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	0	0
Level 3 [Member] | Auction rate securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair Value	$1,994	$1,980

Fair_Value_Measurements_Summar1

Fair Value Measurements - Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs (Detail) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Balance at December 31, 2013	$1,980
Total net unrealized gains, excluding tax impact, included in other comprehensive loss	14
Balance at June 30, 2014	1,994
Total gains or losses for the period included in net loss attributable to the change in unrealized gains or losses relating to assets still held at the reporting date	$0

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail)	0 Months Ended
	Nov. 30, 2013
	Lawsuits
Commitments And Contingencies Disclosure [Abstract]	'
Number of putative, securities class action complaints filed in U.S District Court	2

Astellas_Agreements_Additional

Astellas Agreements - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended				6 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2012	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2012	Mar. 31, 2011	Jun. 30, 2014	Jun. 30, 2013
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'	'	'	'	'	'	'
Recognized license revenue	'	'	'	'	$25	$0.70	$0.30
Additional amount received upon finalization of the general trial design	'	'	'	10	'	'	'
Recognized revenue related to contract services	'	4	1.1	'	'	6.1	2.2
Amount payable under license agreement on achievement of milestone	$95	'	'	'	'	'	'

Restructuring_Costs_Additional

Restructuring Costs - Additional Information (Detail) (USD $)	1 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2013
	Employees
Restructuring And Related Activities [Abstract]	'
Charges for employee termination benefits	$2.20
Charges for asset impairments	$0.70
Restructured of employees to conserve capital include a staff reduction of employees	47

Restructuring_Costs_Schedule_o

Restructuring Costs - Schedule of Restructuring Liability (Detail) (Accrued Severance [Member], USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Accrued Severance [Member]	'
Restructuring Cost and Reserve [Line Items]	'
Beginning balance	$281
Accruals	0
Payments	-226
Ending balance	$55

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Maximum value of common stock issuable under agreement	$25,000,000
Number of shares of common stock sold under the sales agreement	982,016
Gross proceeds from the sales agreement	$1,172,682