Fresh Tracks Therapeutics (FRTX) 10-Q 30 Oct 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 15, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	VICL
Entity Registrant Name	VICAL INC
Entity Central Index Key	819,050
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		91,524,527

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 18,741	$ 20,471
Marketable securities, available-for-sale	19,864	23,499
Restricted cash	3,246	3,182
Receivables and other assets	5,769	4,178
Total current assets	47,620	51,330
Long-term investments	2,077	1,971
Property and equipment, net	2,010	2,639
Intangible assets, net	1,522	1,660
Other assets	191	379
Total assets	53,420	57,979
Current liabilities:
Accounts payable and accrued expenses	3,364	5,201
Deferred revenue	2,110	0
Total current liabilities	5,474	5,201
Long-term liabilities:
Deferred rent	$ 494	$ 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, 91,513 and 90,334 shares issued and outstanding at September 30, 2015, and December 31, 2014, respectively	915	903
Additional paid-in capital	448,976	446,698
Accumulated deficit	(402,550)	(395,667)
Accumulated other comprehensive income (loss)	111	(12)
Total stockholders' equity	47,452	51,922
Total liabilities and stockholders' equity	$ 53,420	$ 57,979

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 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	91,513,000	90,334,000
Common stock, shares outstanding	91,513,000	90,334,000

Statements of Operations

Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues:
Contract revenue	$ 4,427	$ 3,004	$ 12,382	$ 9,073
License and royalty revenue	590	438	1,755	1,321
Total revenues	5,017	3,442	14,137	10,394
Operating expenses:
Research and development	2,128	3,180	8,222	7,705
Manufacturing and production	1,306	2,292	6,626	7,457
General and administrative	1,916	2,366	6,271	7,176
Total operating expenses	5,350	7,838	21,119	22,338
Loss from operations	(333)	(4,396)	(6,982)	(11,944)
Other income:
Investment and other income, net	33	32	99	85
Net loss	$ (300)	$ (4,364)	$ (6,883)	$ (11,859)
Basic and diluted net loss per share	$ 0	$ (0.05)	$ (0.08)	$ (0.13)
Weighted average shares used in computing basic and diluted net loss per share	91,957	89,976	91,600	88,154

Statements of Comprehensive Los

Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (300)	$ (4,364)	$ (6,883)	$ (11,859)
Unrealized gain (loss) on available-for-sale and long-term marketable securities:
Unrealized gain (loss) arising during holding period	98	(69)	123	(59)
Other comprehensive gain (loss)	98	(69)	123	(59)
Total comprehensive loss	$ (202)	$ (4,433)	$ (6,760)	$ (11,918)

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net loss	$ (6,883)	$ (11,859)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	884	1,330
Write-off of abandoned patents	50	331
Loss on sale of property and equipment	2	0
Compensation expense related to stock options and awards	1,534	2,451
Purchase of technology license with common stock	775	0
Changes in operating assets and liabilities:
Receivables and other assets	(1,403)	(99)
Accounts payable and accrued expenses	(1,885)	1,050
Deferred revenue	2,110	(113)
Deferred rent	(313)	(266)
Net cash used in operating activities	(5,129)	(7,175)
Cash flows from investing activities:
Maturities of marketable securities	15,030	8,000
Purchases of marketable securities	(11,500)	(20,437)
Purchases of property and equipment	(58)	(43)
Patent expenditures	(53)	(240)
Net cash provided by (used in) investing activities	3,419	(12,720)
Cash flows from financing activities:
Net proceeds from issuance of common stock	3	3,776
Payment of withholding taxes for net settlement of restricted stock units	(23)	(58)
Net cash (used in) provided by financing activities	(20)	3,718
Net decrease in cash and cash equivalents	(1,730)	(16,177)
Cash and cash equivalents at beginning of period	20,471	38,837
Cash and cash equivalents at end of period	$ 18,741	$ 22,660

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 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, including those 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 September 30, 2015, and for the three and nine months ended September 30, 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 September 30, 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 portions of the Company’s revenue are 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 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 0.1 million and 0.4 million for the three months ended September 30, 2015 and 2014, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 0.4 million and 0.5 million for the nine months ended September 30, 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 nine months ended September 30, 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 2019. 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.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2015
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 Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Research and development $ 93 $ 186 $ 309 $ 628 Manufacturing and production 42 56 123 177 General and administrative 302 488 1,102 1,646 Total stock-based compensation expense $ 437 $ 730 $ 1,534 $ 2,451 During the nine months ended September 30, 2015 and 2014, the Company granted stock-based awards with a total estimated value of $1.9 million and $2.3 million, respectively. At September 30, 2015, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $1.7 million, which is expected to be recognized over a weighted-average period of 1.4 years. Stock-based awards granted during the nine months ended September 30, 2015 and 2014, were equal to 3.3% and 3.0%, respectively, of the outstanding shares of common stock at the end of the applicable period.

Marketable Securities, Availabl

Marketable Securities, Available for Sale	9 Months Ended
	Sep. 30, 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): September 30, 2015 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 5,030 $ 5 $ — $ 5,035 Government-sponsored enterprise securities 2,000 — — 2,000 Corporate bonds 2,005 — — 2,005 Certificates of deposit 10,824 — — 10,824 $ 19,859 $ 5 $ - $ 19,864 December 31, 2014 Amortized Cost Unrealized Gain Unrealized Loss Market 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 September 30, 2015, $0.5 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 nine months ended September 30, 2015. As of September 30, 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	9 Months Ended
	Sep. 30, 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): September 30, December 31, 2015 2014 Employee compensation $ 1,850 $ 2,471 Clinical trial accruals 206 1,686 Accounts payable 316 227 Deferred rent 480 432 Other accrued liabilities 512 385 Total accounts payable and accrued expenses $ 3,364 $ 5,201

Long-Term Investments

Long-Term Investments	9 Months Ended
	Sep. 30, 2015
Investments All Other Investments [Abstract]
Long-Term Investments	5. LONG-TERM INVESTMENTS As of September 30, 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 September 30, 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. As of September 30, 2015, the inputs used in the Company’s discounted cash flow analysis assumed an interest rate of 1.39%, an estimated redemption period of five years and a discount rate of 1.50%. Based on the valuation of the security, the Company has recognized cumulative losses of $0.5 million as of September 30, 2015, none of which were realized during the three months ended September 30, 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 $106,000 and $(43,000) for the nine months ended September 30, 2015 and 2014, respectively. As of September 30, 2015, the Company had recorded cumulative unrealized gains of $0.3 million. The resulting carrying value of the auction rate security at September 30, 2015, was $2.1 million. Any future decline in market value may result in additional losses being recognized.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 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 September 30, 2015 Level 1 Level 2 Level 3 Total Certificates of deposit $ 10,824 $ — $ — $ 10,824 U.S. treasuries 5,035 — — 5,035 Corporate bonds — 2,005 — 2,005 Government-sponsored enterprise securities — 2,000 — 2,000 Auction rate securities — — 2,077 2,077 $ 15,859 $ 4,005 $ 2,077 $ 21,941 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 September 30, 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 September 30, 2015. The Company did not transfer any investments between level categories during the three and nine months ended September 30, 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): Balance at December 31, 2014 $ 1,971 Total unrealized gains, excluding tax impact, included in other comprehensive loss 106 Balance at September 30, 2015 $ 2,077 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	9 Months Ended
	Sep. 30, 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 ® ® 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	9 Months Ended
	Sep. 30, 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 agreements, the Company is performing research and development services and manufacturing services which are being paid for by Astellas. During the three months ended September 30, 2015 and 2014, the Company recognized $4.4 million and $3.0 million, respectively, of revenue related to these contract services. During the nine months ended September 30, 2015 and 2014, the Company recognized $12.4 million and $9.1 million, respectively, of revenue related to these contract services. The Company also recognized $1.5 million and $1.1 million in license revenue under the Astellas agreements during the nine months ended September 30, 2015 and 2014, respectively.
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, VL-2397, formally known as ASP2397. VL-2397 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 nine months ending September 30, 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.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 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 September 30, 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 portions of the Company’s revenue are 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 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 0.1 million and 0.4 million for the three months ended September 30, 2015 and 2014, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 0.4 million and 0.5 million for the nine months ended September 30, 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 nine months ended September 30, 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 2019. 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.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
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 Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Research and development $ 93 $ 186 $ 309 $ 628 Manufacturing and production 42 56 123 177 General and administrative 302 488 1,102 1,646 Total stock-based compensation expense $ 437 $ 730 $ 1,534 $ 2,451

Marketable Securities, Availa17

Marketable Securities, Available for Sale (Tables)	9 Months Ended
	Sep. 30, 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): September 30, 2015 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 5,030 $ 5 $ — $ 5,035 Government-sponsored enterprise securities 2,000 — — 2,000 Corporate bonds 2,005 — — 2,005 Certificates of deposit 10,824 — — 10,824 $ 19,859 $ 5 $ - $ 19,864 December 31, 2014 Amortized Cost Unrealized Gain Unrealized Loss Market 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)	9 Months Ended
	Sep. 30, 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): September 30, December 31, 2015 2014 Employee compensation $ 1,850 $ 2,471 Clinical trial accruals 206 1,686 Accounts payable 316 227 Deferred rent 480 432 Other accrued liabilities 512 385 Total accounts payable and accrued expenses $ 3,364 $ 5,201

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2015 Level 1 Level 2 Level 3 Total Certificates of deposit $ 10,824 $ — $ — $ 10,824 U.S. treasuries 5,035 — — 5,035 Corporate bonds — 2,005 — 2,005 Government-sponsored enterprise securities — 2,000 — 2,000 Auction rate securities — — 2,077 2,077 $ 15,859 $ 4,005 $ 2,077 $ 21,941 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): Balance at December 31, 2014 $ 1,971 Total unrealized gains, excluding tax impact, included in other comprehensive loss 106 Balance at September 30, 2015 $ 2,077 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 - Additio

Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 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	$ 3,246		$ 3,246		$ 3,182
Common stock equivalents excluded from the calculation of diluted net income per share	0.1	0.4	0.4	0.5
Expected forfeiture rate of equity based compensation			8.75%	11.20%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Total Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 437	$ 730	$ 1,534	$ 2,451
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	93	186	309	628
Manufacturing and production [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	42	56	123	177
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 302	$ 488	$ 1,102	$ 1,646

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Estimated value of stock-based awards, granted	$ 1.9	$ 2.3
Unrecognized compensation cost related to unvested options	$ 1.7
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	3.30%	3.00%

Marketable Securities, Availa23

Marketable Securities, Available for Sale - Summary of Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 19,859	$ 23,511
Unrealized Gain	5	0
Unrealized Loss	0	12
Market Value	19,864	23,499
U.S. treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,030	5,558
Unrealized Gain	5	0
Unrealized Loss	0	1
Market Value	5,035	5,557
Government-sponsored enterprise securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,000	7,499
Unrealized Gain	0	0
Unrealized Loss	0	6
Market Value	2,000	7,493
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,005	2,025
Unrealized Gain	0	0
Unrealized Loss	0	5
Market Value	2,005	2,020
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,824	8,429
Unrealized Gain	0	0
Unrealized Loss	0	0
Market Value	$ 10,824	$ 8,429

Marketable Securities, Availa24

Marketable Securities, Available for Sale - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015USD ($)
Investments Debt And Equity Securities [Abstract]
Available-for-sale securities maturing outside of one year	$ 500,000
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 -

Other Balance Sheet Accounts - Summary of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Employee compensation	$ 1,850	$ 2,471
Clinical trial accruals	206	1,686
Accounts payable	316	227
Deferred rent	480	432
Other accrued liabilities	512	385
Total accounts payable and accrued expenses	$ 3,364	$ 5,201

Long-Term Investments - Additio

Long-Term Investments - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Investments Schedule [Abstract]
Auction rate securities held, at par value	$ 2,500,000	$ 2,500,000
Maturity of long-term investment		2,038
Recognized cumulative losses	500,000	$ 500,000
Unrealized gains (losses) on auction rate securities		106,000	$ (43,000)
Cumulative unrealized gains	300,000	300,000
Carrying value of auction rate security	2,077,000	$ 2,077,000		$ 1,971,000
Assumed interest rate		1.39%
Estimated redemption period		5 years
Fair value input discount rate		1.50%
Recognized cumulative losses realized	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Cash Equivalents, Marketable Securities and Long-Term Investments Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 21,941	$ 25,884
Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,824	8,674
U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,035	5,557
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,005	2,020
Government-sponsored enterprise securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,000	7,493
Auction rate securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,077	1,971
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		169
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	15,859	14,400
Level 1 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,824	8,674
Level 1 [Member] | U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,035	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 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		169
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	4,005	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] | 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	2,005	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	2,000	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 2 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,077	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] | 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	$ 2,077	1,971
Level 3 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		$ 0

Fair Value Measurements - Sum28

Fair Value Measurements - Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Fair Value Disclosures [Abstract]
Balance at December 31, 2014	$ 1,971
Total unrealized gains, excluding tax impact, included in other comprehensive loss	106
Balance at September 30, 2015	2,077
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)	Nov. 30, 2013Lawsuit
Commitments And Contingencies Disclosure [Abstract]
Number of putative, securities class action complaints filed in U.S District Court	2

Astellas Out-License Agreements

Astellas Out-License Agreements - Additional Information (Detail) - Collaborative Arrangement [Member] - Astellas Out-License Agreements [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue related to contract services	$ 4.4	$ 3	$ 12.4	$ 9.1
Recognized license revenue			$ 1.5	$ 1.1

Astellas In-License Agreements

Astellas In-License Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014
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
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