Fresh Tracks Therapeutics (FRTX) 10-Q 4 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 15, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
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	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		11,049,962

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 8,460	$ 13,450
Marketable securities, available-for-sale	28,990	23,258
Restricted cash	3,311	3,246
Receivables and other assets	6,249	4,544
Total current assets	47,010	44,498
Long-term investments	2,217	2,052
Property and equipment, net	1,375	1,873
Intangible assets, net	838	1,300
Other assets	388	191
Total assets	51,828	49,914
Current liabilities:
Accounts payable and accrued expenses	3,853	3,912
Deferred revenue	112	250
Total current liabilities	3,965	4,162
Long-term liabilities:
Deferred rent	0	359
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, 11,049 and 9,154 shares issued and outstanding at September 30, 2016, and December 31, 2015, respectively	110	92
Additional paid-in capital	458,698	450,166
Accumulated deficit	(411,106)	(404,905)
Accumulated other comprehensive income	161	40
Total stockholders' equity	47,863	45,393
Total liabilities and stockholders' equity	$ 51,828	$ 49,914

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
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	11,049,000	9,154,000
Common stock, shares outstanding	11,049,000	9,154,000

Statements of Operations

Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Contract revenue	$ 2,310	$ 4,427	$ 10,028	$ 12,382
License and royalty revenue	332	590	1,340	1,755
Total revenues	2,642	5,017	11,368	14,137
Operating expenses:
Research and development	2,599	2,128	7,380	8,222
Manufacturing and production	993	1,306	5,060	6,626
General and administrative	1,621	1,916	5,330	6,271
Total operating expenses	5,213	5,350	17,770	21,119
Loss from operations	(2,571)	(333)	(6,402)	(6,982)
Other income:
Investment and other income, net	48	33	201	99
Net loss	$ (2,523)	$ (300)	$ (6,201)	$ (6,883)
Basic and diluted net loss per share	$ (0.24)	$ (0.03)	$ (0.64)	$ (0.75)
Weighted average shares used in computing basic and diluted net loss per share	10,453	9,196	9,647	9,160

Statements of Comprehensive Los

Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (2,523)	$ (300)	$ (6,201)	$ (6,883)
Unrealized (loss) gain on available-for-sale and long-term marketable securities:
Unrealized (loss) gain arising during holding period, net of tax expense of $7 and $0 for three months ended September 30, 2016 and 2015, respectively, and tax benefit of $56 and $0 for nine months ended September 30, 2016 and 2015, respectively	(22)	98	121	123
Other comprehensive (loss) gain	(22)	98	121	123
Total comprehensive loss	$ (2,545)	$ (202)	$ (6,080)	$ (6,760)

Statements of Comprehensive Lo6

Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Unrealized (loss) gain arising during holding period, tax expense (benefit)	$ 7	$ 0	$ (56)	$ 0

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net loss	$ (6,201)	$ (6,883)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	836	884
Write-off of abandoned patents	374	50
Loss on sale of property and equipment	0	2
Compensation expense related to stock options and awards	804	1,534
Purchase of technology license with common stock	0	775
Changes in operating assets and liabilities:
Receivables and other assets	(1,902)	(1,403)
Accounts payable and accrued expenses	65	(1,885)
Deferred revenue	(138)	2,110
Deferred rent	(416)	(313)
Net cash used in operating activities	(6,578)	(5,129)
Cash flows from investing activities:
Maturities of marketable securities	19,215	15,030
Purchases of marketable securities	(25,143)	(11,500)
Purchases of property and equipment	(230)	(58)
Patent expenditures	0	(53)
Net cash (used in) provided by investing activities	(6,158)	3,419
Cash flows from financing activities:
Net proceeds from issuance of common stock	7,759	3
Payment of withholding taxes for net settlement of restricted stock units	(13)	(23)
Net cash provided by (used in) financing activities	7,746	(20)
Net decrease in cash and cash equivalents	(4,990)	(1,730)
Cash and cash equivalents at beginning of period	13,450	20,471
Cash and cash equivalents at end of period	$ 8,460	$ 18,741

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2016
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 from contract manufacturing agreements. 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, 2016, and for the three and nine months ended September 30, 2016 and 2015, 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, 2015, included in its Annual Report on Form 10-K filed with the SEC. On May 25, 2016, the Company amended its certificate of incorporation to effect a one-for-ten (1:10) reverse stock split. This reverse stock split became effective as of the close of business on May 26, 2016. The reverse stock split had no effect on the par value of its common stock and did not reduce the number of authorized shares of common stock but reduced the number of outstanding shares of common stock by the ratio. Accordingly, the outstanding shares, stock award disclosures, net loss per share, and other per share disclosures for all periods presented have been retrospectively adjusted to reflect the impact of this reverse stock split. The reverse stock split did effect a proportionate adjustment to the per share exercise price and the number of shares of common stock issuable upon the exercise of outstanding stock options, the number of shares of common stock issuable upon the vesting of restricted stock units, or RSUs, and the number of shares of common stock eligible for issuance under our stock incentive plan. No fractional shares were issued in connection with the reverse stock split. Each stockholder’s percentage ownership and proportional voting power generally remained unchanged as a result of the reverse stock split. 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 December 2018. Under certain circumstances, the Company may be able to eliminate the need for the letter of credit. As of September 30, 2016, and December 31, 2015, restricted cash of $3.3 million and $3.2 million, respectively, 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. Contract Manufacturing Revenue Revenue associated with contract manufacturing services is recognized once the service has been rendered and/or upon shipment (or passage of title) of the product to the customer. On occasion, the Company recognizes revenue on a “bill-and-hold” basis in accordance with the authoritative guidance. Under “bill-and-hold” arrangements, revenue is recognized once the product is complete and ready for shipment, title and risk of loss has passed to the customer, management receives a written request from the customer for “bill-and-hold” treatment, the product is segregated from other inventory, and no further performance obligations exist. 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 represent separate units of accounting. Analyzing the arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver services, a right or license to use an asset, or another performance obligation. The delivered item(s) must have value to the customer on a standalone basis and, if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item(s) is considered probable and substantially in the Company’s control. A delivered item is considered a separate unit of accounting when the delivered item has value to the partner on a standalone basis based on the consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research capabilities of the partner and the availability of research expertise in this field in the general marketplace. Arrangement consideration is allocated at the inception of the agreement to all identified units of accounting based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence, or VSOE, of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence of selling price exists, the Company uses its best estimate of the selling price for the deliverable. The amount of allocable arrangement consideration is limited to amounts that are fixed or determinable. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units. Changes in the allocation of the sales price between delivered and undelivered elements can impact revenue recognition but do not change the total revenue recognized under any agreement. If facts and circumstances dictate that the license has standalone value from the undelivered items, which generally include research and development services and the manufacture of drug products, the license is identified as a separate unit of accounting and the amounts allocated to the license are recognized upon the delivery of the license, assuming the other revenue recognition criteria have been met. However, if the amounts allocated to the license through the relative selling price allocation exceed the upfront license fee, the amount recognized upon the delivery of the license is limited to the upfront fee received. If facts and circumstances dictate that the license does not have standalone value, the transaction price, including any upfront license fee payments received, are allocated to the identified separate units of accounting and recognized as those items are delivered. The terms of the Company’s collaboration 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 collaborators 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 17,065 and 8,503 for the three months ended September 30, 2016 and 2015, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 9,800 and 44,960 for the nine months ended September 30, 2016 and 2015, 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 was estimated to be 8.75% annually for each of the nine months ended September 30, 2016 and 2015. 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 previously recognized compensation expense is reversed. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or 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. In February 2016, the FASB issued an amendment to the accounting guidance related to the accounting for leasing transactions. The new standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by leases with lease terms of more than 12 months and will require both lessees and lessors to disclose certain key information about lease transactions. The standard will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the effect that the adoption of the new guidance will have on its financial statements.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
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, 2016 2015 2016 2015 Research and development $ 69 $ 93 $ 228 $ 309 Manufacturing and production 25 42 89 123 General and administrative 119 302 487 1,102 Total stock-based compensation expense $ 213 $ 437 $ 804 $ 1,534 During the nine months ended September 30, 2016 and 2015, the Company granted stock-based awards with a total estimated value of $0.6 million and $1.9 million, respectively. At September 30, 2016, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $0.8 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, 2016 and 2015, were equal to 3.1% and 3.3%, 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, 2016
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, 2016 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 18,783 $ 2 — $ 18,785 Certificates of deposit 10,205 — — 10,205 $ 28,988 $ 2 $ — $ 28,990 December 31, 2015 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 7,027 $ — $ 8 $ 7,019 Corporate bonds 1,000 — — 1,000 Certificates of deposit 15,239 — — 15,239 $ 23,266 $ — $ 8 $ 23,258 At September 30, 2016, none 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, 2016. As of September 30, 2016, 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, 2016
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, 2016 2015 Employee compensation $ 1,949 $ 2,220 Clinical trial accruals 210 102 Accounts payable 698 733 Deferred rent 440 496 Other accrued liabilities 556 361 Total accounts payable and accrued expenses $ 3,853 $ 3,912

Long-Term Investments

Long-Term Investments	9 Months Ended
	Sep. 30, 2016
Investments All Other Investments [Abstract]
Long-Term Investments	5. LONG-TERM INVESTMENTS As of September 30, 2016, 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, 2016. 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, 2016, the inputs used in the Company’s discounted cash flow analysis assumed an interest rate of 1.16%, an estimated redemption period of five years and a discount rate of 1.00%. Based on the valuation of the security, the Company has recognized cumulative losses of $0.4 million as of September 30, 2016, none of which were realized during the nine months ended September 30, 2016. 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 are unrealized gains of $109,000 and $106,000 for the nine months ended September 30, 2016 and 2015, respectively. As of September 30, 2016, the Company had recorded cumulative unrealized gains of $0.4 million. The resulting carrying value of the auction rate security at September 30, 2016, was $2.2 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, 2016
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, 2016 Level 1 Level 2 Level 3 Total Certificates of deposit $ 10,940 $ — $ — $ 10,940 Money market funds 6,590 — — 6,590 U.S. treasuries 18,785 — — 18,785 Auction rate securities — — 2,217 2,217 $ 36,315 $ — $ 2,217 $ 38,532 Fair Value Measurements December 31, 2015 Level 1 Level 2 Level 3 Total Certificates of deposit $ 15,239 $ — $ — $ 15,239 U.S. treasuries 7,019 — — 7,019 Corporate bonds — 1,000 — 1,000 Auction rate securities — — 2,052 2,052 $ 22,258 $ 1,000 $ 2,052 $ 25,310 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, 2016. 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 transfer any investments between level categories during the three and nine months ended September 30, 2016. 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, 2015 $ 2,052 Total unrealized gains, excluding tax impact, included in other comprehensive loss 165 Balance at September 30, 2016 $ 2,217 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, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. COMMITMENTS AND CONTINGENCIES 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, 2016
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, 2016 and 2015, the Company recognized $2.3 million and $4.4 million, respectively, of revenue related to these contract services. During the nine months ended September 30, 2016 and 2015, the Company recognized $9.8 million and $12.4 million, respectively, of revenue related to these contract services. The Company also recognized $1.2 million and $1.5 million in license revenue under the Astellas agreements during the nine months ended September 30, 2016 and 2015, 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, pursuant to which Astellas granted the Company exclusive worldwide license to develop and commercialize a novel antifungal, VL-2397. As consideration for the rights under the license, the Company issued 861,216 shares of its common stock to Astellas and made an up-front payment of $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 ended September 30, 2015. Astellas is also eligible to receive up to $99.0 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.

Facility Lease

Facility Lease	9 Months Ended
	Sep. 30, 2016
Leases [Abstract]
Facility Lease	10. FACILITY LEASE The Company leases approximately 68,400 square feet of manufacturing, research laboratory and office space at a single site in San Diego, California. In July 2016, the term of the lease was extended for 16 months through December 2018, resulting in an additional obligation of $2.9 million.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Stockholders' Equity	11 . STOCKHOLDERS’ EQUITY On August 1, 2016, the Company entered into a stock purchase agreement with AnGes MG, Inc., or AnGes, an existing stockholder, to purchase 1,841,420 shares of the Company’s common stock in a private placement. The shares were sold at a price of $4.24 per share. Gross proceeds totaled approximately $7.8 million. The private placement closed on August 2, 2016. The shares are subject to a two-year lock-up period in which they may not be sold and AnGes has agreed to not increase its ownership position beyond 19.9% and to refrain from taking certain other actions with respect to the Company’s stock, subject to certain conditions. AnGes is entitled to have a representative attend meetings of the Company’s Board of Directors in a non-voting capacity and may in the future be entitled to have a representative appointed to the Company’s Board of Directors, subject to certain conditions. AnGes has also agreed to vote its shares in accordance with the recommendations of the Company’s Board of Directors for so long as it continues to hold a specified percentage of the Company’s outstanding common stock. The Company also agreed under certain circumstances in the future to register the shares for resale by AnGes.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	12. SUBSEQUENT EVENT In October 2016, the Company entered into an At-The-Market Issuance Sales Agreement, or the ATM Agreement, with IFS Securities, Inc. (doing business as Brinson Patrick, a division of IFS Securities, Inc.), or BP, under which the Company may issue and sell up to $10.0 million of shares of its common stock from time to time. Under the ATM Agreement, the Company may deliver placement notices that will set the parameters for the sale of shares, including the number of shares to be issued, the time period during which sales are requested to be made, any limitation on the number of shares that may be sold in any one trading day and any minimum price below which sales may not be made. Subject to the terms and conditions of the ATM Agreement, BP may sell the shares only by methods deemed to be an “at the market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including without limitation sales made directly through the Nasdaq Capital Market, on any other existing trading market for the Company’s common stock or to or through a market maker. BP will use commercially reasonable efforts consistent with its normal trading and sales practices to sell the shares in accordance with the terms of the ATM Agreement and any applicable placement notice. The ATM Agreement may be terminated by the Company upon prior notice to BP or by BP upon prior notice to the Company, or at any time under certain circumstances, including but not limited to the occurrence of a material adverse effect on the Company. The Company has no obligation to sell any shares under the ATM Agreement, and both the Company and BP may at any time suspend the sale of shares under the ATM Agreement. To date the Company has not sold any shares of common stock under the ATM Agreement.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2016
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 December 2018. Under certain circumstances, the Company may be able to eliminate the need for the letter of credit. As of September 30, 2016, and December 31, 2015, restricted cash of $3.3 million and $3.2 million, respectively, 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.
Contract Manufacturing Revenue	Contract Manufacturing Revenue Revenue associated with contract manufacturing services is recognized once the service has been rendered and/or upon shipment (or passage of title) of the product to the customer. On occasion, the Company recognizes revenue on a “bill-and-hold” basis in accordance with the authoritative guidance. Under “bill-and-hold” arrangements, revenue is recognized once the product is complete and ready for shipment, title and risk of loss has passed to the customer, management receives a written request from the customer for “bill-and-hold” treatment, the product is segregated from other inventory, and no further performance obligations exist.
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 represent separate units of accounting. Analyzing the arrangement to identify deliverables requires the use of judgment, and each deliverable may be an obligation to deliver services, a right or license to use an asset, or another performance obligation. The delivered item(s) must have value to the customer on a standalone basis and, if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item(s) is considered probable and substantially in the Company’s control. A delivered item is considered a separate unit of accounting when the delivered item has value to the partner on a standalone basis based on the consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research capabilities of the partner and the availability of research expertise in this field in the general marketplace. Arrangement consideration is allocated at the inception of the agreement to all identified units of accounting based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence, or VSOE, of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence of selling price exists, the Company uses its best estimate of the selling price for the deliverable. The amount of allocable arrangement consideration is limited to amounts that are fixed or determinable. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units. Changes in the allocation of the sales price between delivered and undelivered elements can impact revenue recognition but do not change the total revenue recognized under any agreement. If facts and circumstances dictate that the license has standalone value from the undelivered items, which generally include research and development services and the manufacture of drug products, the license is identified as a separate unit of accounting and the amounts allocated to the license are recognized upon the delivery of the license, assuming the other revenue recognition criteria have been met. However, if the amounts allocated to the license through the relative selling price allocation exceed the upfront license fee, the amount recognized upon the delivery of the license is limited to the upfront fee received. If facts and circumstances dictate that the license does not have standalone value, the transaction price, including any upfront license fee payments received, are allocated to the identified separate units of accounting and recognized as those items are delivered. The terms of the Company’s collaboration 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 collaborators 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 17,065 and 8,503 for the three months ended September 30, 2016 and 2015, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 9,800 and 44,960 for the nine months ended September 30, 2016 and 2015, 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 was estimated to be 8.75% annually for each of the nine months ended September 30, 2016 and 2015. 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 previously recognized compensation expense is reversed.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or 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. In February 2016, the FASB issued an amendment to the accounting guidance related to the accounting for leasing transactions. The new standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by leases with lease terms of more than 12 months and will require both lessees and lessors to disclose certain key information about lease transactions. The standard will be effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the effect that the adoption of the new guidance will have on its financial statements.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 2015 2016 2015 Research and development $ 69 $ 93 $ 228 $ 309 Manufacturing and production 25 42 89 123 General and administrative 119 302 487 1,102 Total stock-based compensation expense $ 213 $ 437 $ 804 $ 1,534

Marketable Securities, Availa21

Marketable Securities, Available for Sale (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 18,783 $ 2 — $ 18,785 Certificates of deposit 10,205 — — 10,205 $ 28,988 $ 2 $ — $ 28,990 December 31, 2015 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 7,027 $ — $ 8 $ 7,019 Corporate bonds 1,000 — — 1,000 Certificates of deposit 15,239 — — 15,239 $ 23,266 $ — $ 8 $ 23,258

Other Balance Sheet Accounts (T

Other Balance Sheet Accounts (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 2015 Employee compensation $ 1,949 $ 2,220 Clinical trial accruals 210 102 Accounts payable 698 733 Deferred rent 440 496 Other accrued liabilities 556 361 Total accounts payable and accrued expenses $ 3,853 $ 3,912

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 Level 1 Level 2 Level 3 Total Certificates of deposit $ 10,940 $ — $ — $ 10,940 Money market funds 6,590 — — 6,590 U.S. treasuries 18,785 — — 18,785 Auction rate securities — — 2,217 2,217 $ 36,315 $ — $ 2,217 $ 38,532 Fair Value Measurements December 31, 2015 Level 1 Level 2 Level 3 Total Certificates of deposit $ 15,239 $ — $ — $ 15,239 U.S. treasuries 7,019 — — 7,019 Corporate bonds — 1,000 — 1,000 Auction rate securities — — 2,052 2,052 $ 22,258 $ 1,000 $ 2,052 $ 25,310
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, 2015 $ 2,052 Total unrealized gains, excluding tax impact, included in other comprehensive loss 165 Balance at September 30, 2016 $ 2,217 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) $ in Thousands	May 25, 2016	Sep. 30, 2016USD ($)shares	Sep. 30, 2015shares	Sep. 30, 2016USD ($)shares	Sep. 30, 2015shares	Dec. 31, 2015USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Reverse stock split, description				one-for-ten (1:10) reverse stock split
Reverse stock split, ratio	10
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 December 2018.
Restricted cash | $		$ 3,311		$ 3,311		$ 3,246
Common stock equivalents excluded from the calculation of diluted net income per share | shares		17,065	8,503	9,800	44,960
Expected forfeiture rate of equity based compensation				8.75%	8.75%

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 213	$ 437	$ 804	$ 1,534
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	69	93	228	309
Manufacturing and production [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	25	42	89	123
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 119	$ 302	$ 487	$ 1,102

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Estimated value of stock-based awards, granted	$ 0.6	$ 1.9
Unrecognized compensation cost related to unvested options	$ 0.8
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	3.10%	3.30%

Marketable Securities, Availa27

Marketable Securities, Available for Sale - Summary of Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 28,988	$ 23,266
Unrealized Gain	2	0
Unrealized Loss	0	8
Market Value	28,990	23,258
U.S. treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,783	7,027
Unrealized Gain	2	0
Unrealized Loss	0	8
Market Value	18,785	7,019
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,205	15,239
Unrealized Gain	0	0
Unrealized Loss	0	0
Market Value	$ 10,205	15,239
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,000
Unrealized Gain		0
Unrealized Loss		0
Market Value		$ 1,000

Marketable Securities, Availa28

Marketable Securities, Available for Sale - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016USD ($)
Investments Debt And Equity Securities [Abstract]
Available-for-sale securities maturing outside of one year	$ 0
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, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Employee compensation	$ 1,949	$ 2,220
Clinical trial accruals	210	102
Accounts payable	698	733
Deferred rent	440	496
Other accrued liabilities	556	361
Total accounts payable and accrued expenses	$ 3,853	$ 3,912

Long-Term Investments - Additio

Long-Term Investments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Investments Schedule [Abstract]
Auction rate securities held, at par value	$ 2,500,000
Maturity of long-term investment	2,038
Recognized cumulative losses	$ 400,000
Unrealized gains on auction rate securities	109,000	$ 106,000
Cumulative unrealized gains	400,000
Carrying value of auction rate security	$ 2,217,000		$ 2,052,000
Assumed interest rate	1.16%
Estimated redemption period	5 years
Fair value input discount rate	1.00%
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, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 38,532	$ 25,310
Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,940	15,239
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	6,590
U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	18,785	7,019
Auction rate securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,217	2,052
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		1,000
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	36,315	22,258
Level 1 [Member] | Certificates of deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,940	15,239
Level 1 [Member] | Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	6,590
Level 1 [Member] | U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	18,785	7,019
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] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	1,000
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
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] | Auction rate securities [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		1,000
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,217	2,052
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
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] | Auction rate securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 2,217	2,052
Level 3 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		$ 0

Fair Value Measurements - Sum32

Fair Value Measurements - Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Fair Value Disclosures [Abstract]
Balance at December 31, 2015	$ 2,052
Total unrealized gains, excluding tax impact, included in other comprehensive loss	165
Balance at September 30, 2016	2,217
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

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue related to contract services	$ 2.3	$ 4.4	$ 9.8	$ 12.4
Recognized license revenue			$ 1.2	$ 1.5

Astellas In-License Agreements

Astellas In-License Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Purchase of technology license with common stock		$ 0	$ 775,000
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	$ 99,000,000
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

Facility Lease - Additional Inf

Facility Lease - Additional Information (Detail) - California [Member] $ in Millions	1 Months Ended
	Jul. 31, 2016USD ($)	Sep. 30, 2016ft²
Facility Lease [Line Items]
Area for leasing facility of manufacturing, research laboratory and office space | ft²		68,400
Renewal period for lease for lease beyond its expiration	16 months
Renewal lease agreement expiry date	Dec. 31, 2018
Additional obligation incurred | $	$ 2.9

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ in Millions	Aug. 01, 2016USD ($)$ / sharesshares
Stockholders Equity [Line Items]
Private placement, share lock-up period	2 years
Maximum [Member]
Stockholders Equity [Line Items]
Equity position under stock purchase agreement	19.90%
Stock Purchase Agreement with AnGes, MG, Inc in Private Placement [Member]
Stockholders Equity [Line Items]
Private placement, shares | shares	1,841,420
Private placement, price per share | $ / shares	$ 4.24
Private placement, gross proceeds | $	$ 7.8
Private placement, closing date	Aug. 2, 2016

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Subsequent Event [Line Items]
Shares of common stock issued during period under At-The-Market Issuance Sales Agreement	0
Subsequent event [Member]
Subsequent Event [Line Items]
At-The-Market Issuance Sales Agreement, maximum value of common stock to be issued		$ 10,000,000