Fresh Tracks Therapeutics (FRTX) 10-Q 8 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	VICL
Entity Registrant Name	VICAL INC
Entity Central Index Key	819050
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		91,397,834

Balance_Sheets

Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$17,666	$20,471
Marketable securities, available-for-sale	23,385	23,499
Restricted cash	3,182	3,182
Receivables and other assets	3,709	4,178
Total current assets	47,942	51,330
Long-term investments	2,034	1,971
Property and equipment, net	2,427	2,639
Intangible assets, net	1,596	1,660
Other assets	379	379
Total assets	54,378	57,979
Current liabilities:
Accounts payable and accrued expenses	4,099	5,201
Deferred revenue	30	0
Total current liabilities	4,129	5,201
Long-term liabilities:
Deferred rent	737	856
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, 91,376 and 90,334 shares issued and outstanding at March 31, 2015, and December 31, 2014, respectively	914	903
Additional paid-in capital	448,019	446,698
Accumulated deficit	-399,488	-395,667
Accumulated other comprehensive income (loss)	67	-12
Total stockholders' equity	49,512	51,922
Total liabilities and stockholders' equity	$54,378	$57,979

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	160,000,000	160,000,000
Common stock, shares issued	91,376,000	90,334,000
Common stock, shares outstanding	91,376,000	90,334,000

Statements_of_Operations

Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Contract and grant revenue	$4,274	$2,118
License and royalty revenue	670	329
Total revenues	4,944	2,447
Operating expenses:
Research and development	3,637	2,146
Manufacturing and production	2,941	1,515
General and administrative	2,223	2,269
Total operating expenses	8,801	5,930
Loss from operations	-3,857	-3,483
Other income:
Investment and other income, net	36	28
Net loss	($3,821)	($3,455)
Basic and diluted net loss per share	($0.04)	($0.04)
Weighted average shares used in computing basic and diluted net loss per share	90,870	87,110

Statements_of_Comprehensive_Lo

Statements of Comprehensive Loss (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net loss	($3,821)	($3,455)
Unrealized gain (loss) on available-for-sale and long-term marketable securities:
Unrealized gain (loss) arising during holding period	79	-17
Other comprehensive gain (loss)	79	-17
Total comprehensive loss	($3,742)	($3,472)

Statements_of_Cash_Flows

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	($3,821)	($3,455)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	301	467
Write-off of abandoned patents and licensed technology	46
Compensation expense related to stock options and awards	571	837
Purchase of technology license with common stock	775	0
Changes in operating assets and liabilities:
Receivables and other assets	469	213
Accounts payable and accrued expenses	-1,117	-298
Deferred revenue	30	-37
Deferred rent	-103	-87
Net cash used in operating activities	-2,849	-2,360
Cash flows from investing activities:
Maturities of marketable securities	4,023	6,240
Purchases of marketable securities	-3,912	-1,804
Purchases of property and equipment	-23	-16
Patent expenditures	-30	-112
Net cash provided by investing activities	58	4,308
Cash flows from financing activities:
Net proceeds from issuance of common stock	2	0
Payment of withholding taxes for net settlement of restricted stock units	-16	-29
Net cash used in financing activities	-14	-29
Net (decrease) increase in cash and cash equivalents	-2,805	1,919
Cash and cash equivalents at beginning of period	20,471	38,837
Cash and cash equivalents at end of period	$17,666	$40,756

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
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 March 31, 2015, and for the three months ended March 31, 2015 and 2014, 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, 2014, included in its Annual Report on Form 10-K filed with the SEC.
	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 ninety days or less and can be liquidated without prior notice or penalty. Investments with an original maturity of more than ninety 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 (loss), 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 each of March 31, 2015, and December 31, 2014, restricted cash of $3.2 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.
	Multiple-element arrangements
	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 represents 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 partnership agreements provide for milestone payments upon achievement of certain regulatory and commercial events. Under the Milestone Method, 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 loss per share excludes any assumed exercise of stock options and any assumed issuance of common stock under restricted stock units as the effect would be antidilutive. Common stock equivalents of 0.7 million and 0.6 million for the three months ended March 31, 2015 and 2014, 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 forms of equity compensation based on their fair value at the date of grant 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 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 ratably over the requisite service period. The expected forfeiture rate of all equity-based compensation is based on observed historical patterns of the Company’s employees and is estimated to be 8.75% and 11.2% annually for each of the three months ended March 31, 2015 and 2014, respectively.
	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 Pronouncements
	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 2018. The Company is evaluating the alternative transition methods and the potential effects of the adoption of this update on its financial statements.
	In August 2014, the FASB issued an amendment to the accounting guidance related to the evaluation of an entity to continue as a going concern. The amendment establishes management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern in connection with preparing financial statements for each annual and interim reporting period. The amendment also gives guidance to determine whether to disclose information about relevant conditions and events when there is substantial doubt about an entity’s ability to continue as a going concern. The amended guidance is effective prospectively for fiscal years beginning after December 15, 2016. The new guidance will not have an impact on the Company’s financial position, results of operations or cash flows.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based 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
		March 31,
		2015		2014
	Research and development	$	111	$	210
	Manufacturing and production		34		45
	General and administrative		426		582
	Total stock-based compensation expense	$	571	$	837
	During the three months ended March 31, 2015 and 2014, the Company granted stock-based awards with a total estimated value of $1.7 million and $2.1 million, respectively. At March 31, 2015, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $2.8 million, which is expected to be recognized over a weighted-average period of 1.4 years. Stock-based awards granted during the three months ended March 31, 2015 and 2014, were equal to 2.9% and 2.7%, respectively, of the outstanding shares of common stock at the end of the applicable period.

Marketable_Securities_Availabl

Marketable Securities, Available for Sale	3 Months Ended
	Mar. 31, 2015
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):
	March 31, 2015	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	5,548	$	4	$	—	$	5,552
	Government-sponsored enterprise securities		5,499		1		—		5,500
	Corporate bonds		2,018		—		1		2,017
	Certificates of deposit		10,316		—		—		10,316
		$	23,381	$	5	$	1	$	23,385
	December 31, 2014	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	5,558	$	—	$	1	$	5,557
	Government-sponsored enterprise securities		7,499		—		6		7,493
	Corporate bonds		2,025		—		5		2,020
	Certificates of deposit		8,429		—		—		8,429
		$	23,511	$	—	$	12	$	23,499
	At March 31, 2015, $6.3 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 three months ended March 31, 2015. As of March 31, 2015, 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	3 Months Ended
	Mar. 31, 2015
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):
		March 31,		December 31,
		2015		2014
	Employee compensation	$	1,432	$	2,471
	Clinical trial accruals		1,091		1,686
	Accounts payable		670		227
	Deferred rent		448		432
	Other accrued liabilities		458		385
	Total accounts payable and accrued expenses	$	4,099	$	5,201

LongTerm_Investments

Long-Term Investments	3 Months Ended
	Mar. 31, 2015
Investments, All Other Investments [Abstract]
Long-Term Investments	5.       LONG-TERM INVESTMENTS
	As of March 31, 2015, 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 March 31, 2015. 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 utilizing a discounted cash flow analysis. The key drivers of the valuation model include the expected term, collateral 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 as of March 31, 2015, none of which were realized during the three months ended March 31, 2015. The losses when recognized are included in investment and other income. The market value of the security has partially recovered. Included in other comprehensive income (loss) are unrealized gains (losses) of $63,000 and $(12,000) for the three months ended March 31, 2015 and 2014, respectively. As of March 31, 2015, the Company had recorded cumulative unrealized gains of $0.2 million. The resulting carrying value of the auction rate security at March 31, 2015, was $2.0 million. Any future decline in market value may result in additional losses being recognized.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
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
	March 31, 2015		Level 1		Level 2		Level 3		Total
	Certificates of deposit		$	10,561	$	—	$	—	$	10,561
	Money market funds			—		—		—		—
	U.S. treasuries			5,552		—		—		5,552
	Corporate bonds			—		2,017		—		2,017
	Government-sponsored enterprise securities			—		5,500		—		5,500
	Auction rate securities			—		—		2,034		2,034
			$	16,113	$	7,517	$	2,034	$	25,664
			Fair Value Measurements
	December 31, 2014		Level 1		Level 2		Level 3		Total
	Certificates of deposit		$	8,674	$	—	$	—	$	8,674
	Money market funds			169		—		—		169
	U.S. treasuries			5,557		—		—		5,557
	Corporate bonds			—		2,020		—		2,020
	Government-sponsored enterprise securities			—		7,493		—		7,493
	Auction rate securities			—		—		1,971		1,971
			$	14,400	$	9,513	$	1,971	$	25,884
	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 March 31, 2015. 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 March 31, 2015. The Company did not transfer any investments between level categories during the three months ended March 31, 2015. 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):
			Three Months
			Ended
			March 31,
			2015
	Balance at December 31, 2014		$	1,971
	Total net unrealized gains, excluding tax impact, included in other comprehensive loss			63
	Balance at March 31, 2015		$	2,034
	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	3 Months Ended
	Mar. 31, 2015
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 May 12, 2014, the lead plaintiff filed a first amended 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. On June 9, 2014, defendants filed a motion to dismiss the first amended complaint and a motion to strike certain allegations in the amended complaint. On March 9, 2015, the Court granted defendants’ motion to dismiss the first amended complaint and terminated as moot defendants’ motion to strike. Lead plaintiff was granted leave to amend his first amended complaint on or before March 25, 2015. Lead plaintiff chose not to amend his complaint and instead stipulated to an entry of judgment. On April 28, 2015, the Court entered final judgment dismissing the action.
	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_License_Agreements

Astellas License Agreements	3 Months Ended
	Mar. 31, 2015
Astellas Out-License Agreements [Member]
Astellas License Agreements	8.       ASTELLAS OUT-LICENSE 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 $0.5 million and $0.3 million in license revenue under the Astellas agreements during the three months ended March 31, 2015 and 2014, 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 months ended March 31, 2015 and 2014, the Company recognized $4.3 million and $2.1 million, respectively, of revenue related to these contract services.
Astellas In-License Agreements [Member]
Astellas License Agreements	9.       ASTELLAS IN-LICENSE AGREEMENTS
	In March 2015, the Company entered into license and stock purchase agreements with Astellas, granting Vical exclusive worldwide license to develop and commercialize a novel antifungal, ASP2397. ASP2397 is a potential therapeutic for invasive fungal infections, including invasive aspergillosis. Astellas received 861,216 shares of unregistered Vical common stock and $250,000 in cash. The $250,000 cash payment and the fair value of the common stock issued of $775,094 were included in research and development expenses during the three months ending March 31, 2015. Astellas will also be eligible to receive up to $100 million in aggregate milestone payments, the vast majority of which are commercial and sales milestones, and single-digit royalties on net sales of commercial products.

Subsequent_Event

Subsequent Event	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Event	10.       SUBSEQUENT EVENT
	In April 2015, the Company entered into a $4 million contract with the IPPOX Foundation to manufacture HIV-antigen plasmid DNA as a component of vaccine regimens to be evaluated in clinical trials for the prevention of HIV infection.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
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 ninety days or less and can be liquidated without prior notice or penalty. Investments with an original maturity of more than ninety 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 (loss), 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 each of March 31, 2015, and December 31, 2014, restricted cash of $3.2 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.
Multiple-element arrangements	Multiple-element arrangements
	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 represents 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 partnership agreements provide for milestone payments upon achievement of certain regulatory and commercial events. Under the Milestone Method, 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 loss per share excludes any assumed exercise of stock options and any assumed issuance of common stock under restricted stock units as the effect would be antidilutive. Common stock equivalents of 0.7 million and 0.6 million for the three months ended March 31, 2015 and 2014, 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 forms of equity compensation based on their fair value at the date of grant 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 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 ratably over the requisite service period. The expected forfeiture rate of all equity-based compensation is based on observed historical patterns of the Company’s employees and is estimated to be 8.75% and 11.2% annually for each of the three months ended March 31, 2015 and 2014, respectively.
	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 Pronouncements	Recent Accounting Pronouncements
	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 2018. The Company is evaluating the alternative transition methods and the potential effects of the adoption of this update on its financial statements.
	In August 2014, the FASB issued an amendment to the accounting guidance related to the evaluation of an entity to continue as a going concern. The amendment establishes management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern in connection with preparing financial statements for each annual and interim reporting period. The amendment also gives guidance to determine whether to disclose information about relevant conditions and events when there is substantial doubt about an entity’s ability to continue as a going concern. The amended guidance is effective prospectively for fiscal years beginning after December 15, 2016. The new guidance will not have an impact on the Company’s financial position, results of operations or cash flows.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based 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
		March 31,
		2015		2014
	Research and development	$	111	$	210
	Manufacturing and production		34		45
	General and administrative		426		582
	Total stock-based compensation expense	$	571	$	837

Marketable_Securities_Availabl1

Marketable Securities, Available for Sale (Tables)	3 Months Ended
	Mar. 31, 2015
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):
	March 31, 2015	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	5,548	$	4	$	—	$	5,552
	Government-sponsored enterprise securities		5,499		1		—		5,500
	Corporate bonds		2,018		—		1		2,017
	Certificates of deposit		10,316		—		—		10,316
		$	23,381	$	5	$	1	$	23,385
	December 31, 2014	Amortized		Unrealized		Unrealized		Market
		Cost		Gain		Loss		Value
	U.S. treasuries	$	5,558	$	—	$	1	$	5,557
	Government-sponsored enterprise securities		7,499		—		6		7,493
	Corporate bonds		2,025		—		5		2,020
	Certificates of deposit		8,429		—		—		8,429
		$	23,511	$	—	$	12	$	23,499

Other_Balance_Sheet_Accounts_T

Other Balance Sheet Accounts (Tables)	3 Months Ended
	Mar. 31, 2015
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):
		March 31,		December 31,
		2015		2014
	Employee compensation	$	1,432	$	2,471
	Clinical trial accruals		1,091		1,686
	Accounts payable		670		227
	Deferred rent		448		432
	Other accrued liabilities		458		385
	Total accounts payable and accrued expenses	$	4,099	$	5,201

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
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
	March 31, 2015	Level 1		Level 2		Level 3		Total
	Certificates of deposit	$	10,561	$	—	$	—	$	10,561
	Money market funds		—		—		—		—
	U.S. treasuries		5,552		—		—		5,552
	Corporate bonds		—		2,017		—		2,017
	Government-sponsored enterprise securities		—		5,500		—		5,500
	Auction rate securities		—		—		2,034		2,034
		$	16,113	$	7,517	$	2,034	$	25,664
		Fair Value Measurements
	December 31, 2014	Level 1		Level 2		Level 3		Total
	Certificates of deposit	$	8,674	$	—	$	—	$	8,674
	Money market funds		169		—		—		169
	U.S. treasuries		5,557		—		—		5,557
	Corporate bonds		—		2,020		—		2,020
	Government-sponsored enterprise securities		—		7,493		—		7,493
	Auction rate securities		—		—		1,971		1,971
		$	14,400	$	9,513	$	1,971	$	25,884
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):
		Three Months
		Ended
		March 31, 2015
	Balance at December 31, 2014	$	1,971
	Total net unrealized gains, excluding tax impact, included in other comprehensive loss		63
	Balance at March 31, 2015	$	2,034
	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	$	—

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
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	$3,182		$3,182
Common stock equivalents excluded from the calculation of diluted net income per share	0.7	0.6
Expected forfeiture rate of equity based compensation	8.75%	11.20%

StockBased_Compensation_Summar

Stock-Based Compensation - Summary of Total Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$571	$837
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	111	210
Manufacturing and production [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	34	45
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$426	$582

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Estimated value of stock-based awards, granted	$1.70	$2.10
Unrecognized compensation cost related to unvested options	$2.80
Unvested stock-based awards expected to be recognized, weighted-average period	1 year 4 months 24 days
Portion of stock-based awards granted from outstanding common shares	2.90%	2.70%

Marketable_Securities_Availabl2

Marketable Securities, Available for Sale - Summary of Available-for-Sale Marketable Securities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$23,381	$23,511
Unrealized Gain	5	0
Unrealized Loss	1	12
Market Value	23,385	23,499
U.S. treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,548	5,558
Unrealized Gain	4	0
Unrealized Loss	0	1
Market Value	5,552	5,557
Government-sponsored enterprise securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,499	7,499
Unrealized Gain	1	0
Unrealized Loss	0	6
Market Value	5,500	7,493
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,018	2,025
Unrealized Gain	0	0
Unrealized Loss	1	5
Market Value	2,017	2,020
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,316	8,429
Unrealized Gain	0	0
Unrealized Loss	0	0
Market Value	$10,316	$8,429

Marketable_Securities_Availabl3

Marketable Securities, Available for Sale - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Available-for-sale securities maturing outside of one year	$6,300,000
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 $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Employee compensation	$1,432	$2,471
Clinical trial accruals	1,091	1,686
Accounts payable	670	227
Deferred rent	448	432
Other accrued liabilities	458	385
Total accounts payable and accrued expenses	$4,099	$5,201

LongTerm_Investments_Additiona

Long-Term Investments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
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 gains (losses) on auction rate securities	63,000	-12,000
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 $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$25,664	$25,884
Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,561	8,674
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	169
U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,552	5,557
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,017	2,020
Government-sponsored enterprise securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,500	7,493
Auction rate securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,034	1,971
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	16,113	14,400
Level 1 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,561	8,674
Level 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	169
Level 1 [Member] | U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,552	5,557
Level 1 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	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	7,517	9,513
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	2,017	2,020
Level 2 [Member] | Government-sponsored enterprise securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,500	7,493
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	2,034	1,971
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	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	$2,034	$1,971

Fair_Value_Measurements_Summar1

Fair Value Measurements - Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Balance at December 31, 2014	$1,971
Total net unrealized gains, excluding tax impact, included in other comprehensive loss	63
Balance at March 31, 2015	2,034
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_OutLicense_Agreements

Astellas Out-License Agreements - Additional Information (Detail) (Collaborative Arrangement [Member], Astellas Out-License Agreements [Member], USD $)	1 Months Ended	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2011
Collaborative Arrangement [Member] | Astellas Out-License Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Recognized license revenue		$0.50	$0.30	$25
Milestone payment upon finalization of the trial design	10
Revenue related to contract services		$4.30	$2.10

Astellas_InLicense_Agreements_

Astellas In-License Agreements - Additional Information (Detail) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Purchase of technology license with common stock	$775,000	$0
Astellas In-License Agreements [Member] | Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Restricted stock issued, shares			861,216
Potential future milestone payments	100,000,000		100,000,000
Astellas In-License Agreements [Member] | Collaborative Arrangement [Member] | Research and development [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cash payment for license agreement			250,000
Purchase of technology license with common stock	$775,094

Subsequent_Event_Additional_In

Subsequent Event - Additional Information (Detail) (Subsequent Event [Member], IPPOX Foundation [Member], USD $)	Apr. 30, 2015
In Millions, unless otherwise specified
Subsequent Event [Member] | IPPOX Foundation [Member]
Subsequent Event [Line Items]
Contractual obligation to manufacture HIV-antigen plasmid DNA	$4