Document and Entity Information
| Document and Entity Information - shares | 9 Months Ended | |
| Sep. 30, 2017 | Oct. 15, 2017 | |
| Document And Entity Information [Abstract] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Sep. 30, 2017 | |
| Document Fiscal Year Focus | 2,017 | |
| 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 | 12,606,447 |
Balance Sheets
| Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016 |
| Current assets: | ||
| Cash and cash equivalents | $ 10,210 | $ 5,069 |
| Marketable securities, available-for-sale | 22,629 | 30,552 |
| Restricted cash | 192 | 3,311 |
| Deferred contract costs | 9,574 | 5,513 |
| Receivables and other assets | 2,745 | 3,422 |
| Total current assets | 45,350 | 47,867 |
| Long-term investments | 2,189 | 2,046 |
| Property and equipment, net | 598 | 1,173 |
| Intangible assets, net | 730 | 810 |
| Other assets | 747 | 388 |
| Total assets | 49,614 | 52,284 |
| Current liabilities: | ||
| Accounts payable and accrued expenses | 4,078 | 4,127 |
| Deferred revenue | 7,803 | 3,018 |
| Total current liabilities | 11,881 | 7,145 |
| Stockholders' equity: | ||
| Preferred stock, $0.01 par value, 5,000 shares authorized, none issued and outstanding | 0 | 0 |
| Common stock, $0.01 par value, 50,000 shares authorized, 11,548 and 11,052 shares issued and outstanding at September 30, 2017 and December 31, 2016, respectively | 115 | 111 |
| Additional paid-in capital | 460,501 | 458,881 |
| Accumulated deficit | (423,010) | (413,878) |
| Accumulated other comprehensive income | 127 | 25 |
| Total stockholders' equity | 37,733 | 45,139 |
| Total liabilities and stockholders' equity | $ 49,614 | $ 52,284 |
Balance Sheets (Parenthetical)
| Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2017 | Dec. 31, 2016 |
| 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 | 50,000,000 | 50,000,000 |
| Common stock, shares issued | 11,548,000 | 11,052,000 |
| Common stock, shares outstanding | 11,548,000 | 11,052,000 |
Statements of Operations
| Statements of Operations - USD ($) shares in Thousands, $ in Thousands | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Revenues: | ||||
| Contract revenue | $ 3,188 | $ 2,310 | $ 9,458 | $ 10,028 |
| License and royalty revenue | 52 | 332 | 408 | 1,340 |
| Total revenues | 3,240 | 2,642 | 9,866 | 11,368 |
| Operating expenses: | ||||
| Research and development | 3,004 | 2,599 | 9,943 | 7,380 |
| Manufacturing and production | 1,778 | 993 | 4,689 | 5,060 |
| General and administrative | 1,639 | 1,621 | 4,739 | 5,330 |
| Total operating expenses | 6,421 | 5,213 | 19,371 | 17,770 |
| Loss from operations | (3,181) | (2,571) | (9,505) | (6,402) |
| Other income: | ||||
| Investment and other income, net | 93 | 48 | 273 | 201 |
| Net loss | $ (3,088) | $ (2,523) | $ (9,232) | $ (6,201) |
| Basic and diluted net loss per share | $ (0.27) | $ (0.24) | $ (0.82) | $ (0.64) |
| Weighted average shares used in computing basic and diluted net loss per share | 11,458 | 10,453 | 11,237 | 9,647 |
Statements of Comprehensive Los
| Statements of Comprehensive Loss - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Statement Of Income And Comprehensive Income [Abstract] | ||||
| Net loss | $ (3,088) | $ (2,523) | $ (9,232) | $ (6,201) |
| Unrealized gain (loss) on available-for-sale and long-term marketable securities: | ||||
| Unrealized gain (loss) arising during holding period, net of tax benefit (expense) of $10 and $(7) for three months ended September 30, 2017 and 2016, respectively, and $49 and $56 for nine months ended September 30, 2017 and 2016, respectively | 34 | (22) | 102 | 121 |
| Other comprehensive gain (loss) | 34 | (22) | 102 | 121 |
| Total comprehensive loss | $ (3,054) | $ (2,545) | $ (9,130) | $ (6,080) |
Statements of Comprehensive Lo6
| Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Statement Of Income And Comprehensive Income [Abstract] | ||||
| Unrealized gain (loss) arising during holding period, tax benefit (expense) | $ 10 | $ (7) | $ 49 | $ 56 |
Statements of Cash Flows
| Statements of Cash Flows - USD ($) $ in Thousands | 9 Months Ended | |
| Sep. 30, 2017 | Sep. 30, 2016 | |
| Cash flows from operating activities: | ||
| Net loss | $ (9,232) | $ (6,201) |
| Adjustments to reconcile net loss to net cash used in operating activities: | ||
| Depreciation and amortization | 722 | 836 |
| Write-off of abandoned patents | 0 | 374 |
| Compensation expense related to stock options and awards | 611 | 804 |
| Changes in operating assets and liabilities: | ||
| Deferred contract costs | (4,061) | (3,527) |
| Receivables and other assets | 319 | 1,625 |
| Accounts payable and accrued expenses | 174 | 65 |
| Deferred revenue | 4,785 | (138) |
| Deferred rent | (223) | (416) |
| Net cash used in operating activities | (6,905) | (6,578) |
| Cash flows from investing activities: | ||
| Maturities of marketable securities | 20,016 | 19,215 |
| Purchases of marketable securities | (12,175) | (25,078) |
| Purchases of property and equipment | (27) | (230) |
| Net cash provided by (used in) investing activities | 7,814 | (6,093) |
| Cash flows from financing activities: | ||
| Net proceeds from issuance of common stock | 1,116 | 7,759 |
| Payment of withholding taxes for net settlement of restricted stock units | (3) | (13) |
| Net cash provided by financing activities | 1,113 | 7,746 |
| Net increase (decrease) in cash, cash equivalents and restricted cash | 2,022 | (4,925) |
| Cash, cash equivalents and restricted cash at beginning of period | 8,380 | 16,696 |
| Cash, cash equivalents and restricted cash at end of period | $ 10,402 | $ 11,771 |
Basis of Presentation
| Basis of Presentation | 9 Months Ended |
| Sep. 30, 2017 | |
| 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, 2017, and for the three and nine months ended September 30, 2017 and 2016, 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, 2016, 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 was required to maintain a letter of credit securing an amount equal to twelve months of the then current monthly installment of base rent for the original term of the lease for its facilities, which ended on August 31, 2017. In July 2016, the term of the lease was extended for 16 months through December 2018. During the extended term, the Company is required to maintain a letter of credit securing an amount equal to $0.2 million. As of September 30, 2017, and December 31, 2016, restricted cash of $0.2 million and $3.3 million, respectively, was pledged as collateral for the 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. Revenue is recognized for such “bill-and-hold” arrangements in accordance with the authoritative guidance, which requires, among other things, the existence of a valid business purpose for the arrangement, that the “bill-and-hold” arrangement is at the request of the customer, that title and risk of ownership pass to the customer, that the product is complete and ready for shipment, a fixed delivery date that is reasonable and consistent with the customer’s business practices, that the product has been separated from the Company’s inventory, and that no further performance obligations by the Company 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 and Royalty Revenue The Company recognizes revenues from contract services 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. Deferred contract costs were $9.6 million and $5.5 million at September 30, 2017 and December 31, 2016, respectively. 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 RSUs as the effect would be antidilutive. Common stock equivalents of 3,260 and 17,065 for the three months ended September 30, 2017 and 2016, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 1,087 and 9,800 for the nine months ended September 30, 2017 and 2016, 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 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. Forfeitures of stock options and RSUs are recognized as they occur. 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 FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers” which 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 outlines a five-step process for revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards, and also requires enhanced disclosures regarding the nature, amount, timing and uncertainty of revenues and cash flows from contracts with customers. Major provisions include determining which goods and services are distinct and require separate accounting (performance obligations), how variable consideration (which may include change orders and claims) is recognized, whether revenue should be recognized at a point in time or over time and ensuring the time value of money is considered in the transaction price. 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 in the process of evaluating the impact of adopting the new revenue guidance on the Company’s financial position, results of operations, cash flows and related disclosures. Based on the Company’s initial assessment, the Company plans to adopt this new standard using the modified retrospective method which may result in a cumulative effect adjustment as of the date of adoption. At this time, management does not expect the adoption of the new guidance to have a material impact on revenue recognition related to contracts with remaining performance obligations upon the adoption of the standard. The impact on the Company’s financial statements is not expected to be material because, based upon the preliminary analysis of material contracts under the new revenue recognition standard, management has determined the recognition and allocation of revenue upon the delivery or completion of the Company’s performance obligations are consistent with those under the current revenue recognition model. The Company expects to complete its assessment process, including finalizing a transition method for adoption, in the fourth quarter of 2017 and expects to complete its implementation process prior to the adoption of this ASU on January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” 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 and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, “Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amended guidance simplifies the accounting for share-based payment transactions and became effective for annual periods beginning after December 15, 2016. The Company adopted this standard during the first quarter of 2017 and elected to recognize forfeitures as they occur. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures. In November 2016, the FASB issued ASU No. 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash” that changes the presentation of restricted cash and cash equivalents on the statement of cash flows. Restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This new standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, with early adoption permitted. The Company adopted this standard in the third quarter of 2017 on a retrospective basis and has presented the cash flow statement in accordance with the new guidance. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures. |
Stock-Based Compensation
| Stock-Based Compensation | 9 Months Ended |
| Sep. 30, 2017 | |
| 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, 2017 2016 2017 2016 Research and development $ 61 $ 69 $ 184 $ 228 Manufacturing and production 30 25 95 89 General and administrative 92 119 332 487 Total stock-based compensation expense $ 183 $ 213 $ 611 $ 804 During the nine months ended September 30, 2017 and 2016, the Company granted stock-based awards with a total estimated value of $0.7 million and $0.6 million, respectively. At September 30, 2017, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $0.7 million, which is expected to be recognized over a weighted-average period of 1.3 years. Stock-based awards granted during the nine months ended September 30, 2017 and 2016, were equal to 5.1% and 3.1%, 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, 2017 | |
| 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, 2017 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 18,495 $ — $ 11 $ 18,484 Certificates of deposit 4,145 — — 4,145 $ 22,640 $ — $ 11 $ 22,629 December 31, 2016 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 23,295 $ — $ 18 $ 23,277 Certificates of deposit 7,275 — — 7,275 $ 30,570 $ — $ 18 $ 30,552 At September 30, 2017, 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, 2017. As of September 30, 2017, 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, 2017 | |
| 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, 2017 2016 Employee compensation $ 2,045 $ 2,518 Clinical trial accruals 1,005 446 Accounts payable 610 326 Deferred rent — 223 Other accrued liabilities 418 614 Total accounts payable and accrued expenses $ 4,078 $ 4,127 |
Long-Term Investments
| Long-Term Investments | 9 Months Ended |
| Sep. 30, 2017 | |
| Investments All Other Investments [Abstract] | |
| Long-Term Investments | 5. LONG-TERM INVESTMENTS As of September 30, 2017, 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, 2017. 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, 2017, the inputs used in the Company’s discounted cash flow analysis assumed an interest rate of 3.085%, 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, 2017, none of which were realized during the three months ended September 30, 2017. 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 $95,000 and $109,000 for the nine months ended September 30, 2017 and 2016, respectively. As of September 30, 2017, the Company had recorded cumulative unrealized gains of $0.4 million. The resulting carrying value of the auction rate security at September 30, 2017, 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, 2017 | |
| 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, 2017 Level 1 Level 2 Level 3 Total Certificates of deposit $ 4,145 $ — $ — $ 4,145 Money market funds 4,987 — — 4,987 U.S. treasuries 18,484 — — 18,484 Auction rate securities — — 2,189 2,189 $ 27,616 $ — $ 2,189 $ 29,805 Fair Value Measurements December 31, 2016 Level 1 Level 2 Level 3 Total Certificates of deposit $ 7,275 $ — $ — $ 7,275 Money market funds 1,171 — — 1,171 U.S. treasuries 23,277 — — 23,277 Auction rate securities — — 2,046 2,046 $ 31,723 $ — $ 2,046 $ 33,769 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, 2017. 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. As of September 30, 2017 and December 31, 2016, the Company had no investments in Level 2 securities. The Company did not transfer any investments between level categories during the nine months ended September 30, 2017. 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, 2016 $ 2,046 Total unrealized gains, excluding tax impact, included in other comprehensive loss 143 Balance at September 30, 2017 $ 2,189 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, 2017 | |
| 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, 2017 | |
| 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, 2017 and 2016, the Company recognized $3.1 million and $2.3 million, respectively, of revenue related to these contract services. During the nine months ended September 30, 2017 and 2016, the Company recognized $9.1 million and $9.8 million, respectively, of revenue related to these contract services. The Company also recognized $0.2 million and $1.2 million in license revenue under the Astellas agreements during the nine months ended September 30, 2017 and 2016, respectively. |
Stockholders' Equity
| Stockholders' Equity | 9 Months Ended |
| Sep. 30, 2017 | |
| Equity [Abstract] | |
| Stockholders' Equity | 9 . STOCKHOLDERS’ EQUITY On August 1, 2016, the Company entered into a stock purchase agreement with AnGes, 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. 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. During the three months ended September 30, 2017, the Company sold 320,983 shares under the ATM Agreement and received gross proceeds of $824,759. During the nine months ended September 30, 2017, the Company sold 450,883 shares under the ATM Agreement and received gross proceeds of $1,139,871. |
Related Party Transaction
| Related Party Transaction | 9 Months Ended |
| Sep. 30, 2017 | |
| Related Party Transactions [Abstract] | |
| Related Party Transaction | 1 0 . RELATED PARTY TRANSACTION On April 4, 2017, the Company entered into a research collaboration agreement with AnGes. As of the date of the transaction, AnGes held 18.6% of the outstanding stock of the Company. Pursuant to the collaboration agreement, AnGes agreed to make a non-refundable payment to the Company of $750,000 and the Company agreed to conduct certain research activities related to a development program targeting chronic hepatitis B. In exchange for the payment, AnGes received an option to negotiate exclusive rights in Japan related to the program. The parties also agreed to share the costs of prosecuting and maintaining intellectual property rights arising from the research program after such costs reach a specified limit. The decision to sell, license or sublicense rights is a contingent event within the Company’s control. There are no guarantees for any outcomes of the research activities, no purchase obligations required by the Company and no debt or equity arrangements connected with the research activities. There are no other written or oral side agreements between the Company and AnGes that indicate that the funding of the research activities will be repaid. The Company is responsible for the conduct of the research activities. The upfront payment received was deferred and will be recognized as contract revenue as the related research costs are incurred. The deferred revenue is classified as a current liability. During the nine months ended September 30, 2017 the Company recognized $0.4 million of contract revenue related to this collaboration agreement. |
Basis of Presentation (Policies
| Basis of Presentation (Policies) | 9 Months Ended |
| Sep. 30, 2017 | |
| 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 was required to maintain a letter of credit securing an amount equal to twelve months of the then current monthly installment of base rent for the original term of the lease for its facilities, which ended on August 31, 2017. In July 2016, the term of the lease was extended for 16 months through December 2018. During the extended term, the Company is required to maintain a letter of credit securing an amount equal to $0.2 million. As of September 30, 2017, and December 31, 2016, restricted cash of $0.2 million and $3.3 million, respectively, was pledged as collateral for the 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. Revenue is recognized for such “bill-and-hold” arrangements in accordance with the authoritative guidance, which requires, among other things, the existence of a valid business purpose for the arrangement, that the “bill-and-hold” arrangement is at the request of the customer, that title and risk of ownership pass to the customer, that the product is complete and ready for shipment, a fixed delivery date that is reasonable and consistent with the customer’s business practices, that the product has been separated from the Company’s inventory, and that no further performance obligations by the Company 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 and Royalty Revenue | Contract Services and Royalty Revenue The Company recognizes revenues from contract services 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. Deferred contract costs were $9.6 million and $5.5 million at September 30, 2017 and December 31, 2016, respectively. 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 RSUs as the effect would be antidilutive. Common stock equivalents of 3,260 and 17,065 for the three months ended September 30, 2017 and 2016, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 1,087 and 9,800 for the nine months ended September 30, 2017 and 2016, 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 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. Forfeitures of stock options and RSUs are recognized as they occur. 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 FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers” which 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 outlines a five-step process for revenue recognition that focuses on transfer of control, as opposed to transfer of risk and rewards, and also requires enhanced disclosures regarding the nature, amount, timing and uncertainty of revenues and cash flows from contracts with customers. Major provisions include determining which goods and services are distinct and require separate accounting (performance obligations), how variable consideration (which may include change orders and claims) is recognized, whether revenue should be recognized at a point in time or over time and ensuring the time value of money is considered in the transaction price. 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 in the process of evaluating the impact of adopting the new revenue guidance on the Company’s financial position, results of operations, cash flows and related disclosures. Based on the Company’s initial assessment, the Company plans to adopt this new standard using the modified retrospective method which may result in a cumulative effect adjustment as of the date of adoption. At this time, management does not expect the adoption of the new guidance to have a material impact on revenue recognition related to contracts with remaining performance obligations upon the adoption of the standard. The impact on the Company’s financial statements is not expected to be material because, based upon the preliminary analysis of material contracts under the new revenue recognition standard, management has determined the recognition and allocation of revenue upon the delivery or completion of the Company’s performance obligations are consistent with those under the current revenue recognition model. The Company expects to complete its assessment process, including finalizing a transition method for adoption, in the fourth quarter of 2017 and expects to complete its implementation process prior to the adoption of this ASU on January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” 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 and related disclosures. In March 2016, the FASB issued ASU No. 2016-09, “Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amended guidance simplifies the accounting for share-based payment transactions and became effective for annual periods beginning after December 15, 2016. The Company adopted this standard during the first quarter of 2017 and elected to recognize forfeitures as they occur. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures. In November 2016, the FASB issued ASU No. 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash” that changes the presentation of restricted cash and cash equivalents on the statement of cash flows. Restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This new standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, with early adoption permitted. The Company adopted this standard in the third quarter of 2017 on a retrospective basis and has presented the cash flow statement in accordance with the new guidance. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures. |
Stock-Based Compensation (Table
| Stock-Based Compensation (Tables) | 9 Months Ended |
| Sep. 30, 2017 | |
| 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, 2017 2016 2017 2016 Research and development $ 61 $ 69 $ 184 $ 228 Manufacturing and production 30 25 95 89 General and administrative 92 119 332 487 Total stock-based compensation expense $ 183 $ 213 $ 611 $ 804 |
Marketable Securities, Availa20
| Marketable Securities, Available for Sale (Tables) | 9 Months Ended |
| Sep. 30, 2017 | |
| 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, 2017 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 18,495 $ — $ 11 $ 18,484 Certificates of deposit 4,145 — — 4,145 $ 22,640 $ — $ 11 $ 22,629 December 31, 2016 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 23,295 $ — $ 18 $ 23,277 Certificates of deposit 7,275 — — 7,275 $ 30,570 $ — $ 18 $ 30,552 |
Other Balance Sheet Accounts (T
| Other Balance Sheet Accounts (Tables) | 9 Months Ended |
| Sep. 30, 2017 | |
| 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, 2017 2016 Employee compensation $ 2,045 $ 2,518 Clinical trial accruals 1,005 446 Accounts payable 610 326 Deferred rent — 223 Other accrued liabilities 418 614 Total accounts payable and accrued expenses $ 4,078 $ 4,127 |
Fair Value Measurements (Tables
| Fair Value Measurements (Tables) | 9 Months Ended |
| Sep. 30, 2017 | |
| 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, 2017 Level 1 Level 2 Level 3 Total Certificates of deposit $ 4,145 $ — $ — $ 4,145 Money market funds 4,987 — — 4,987 U.S. treasuries 18,484 — — 18,484 Auction rate securities — — 2,189 2,189 $ 27,616 $ — $ 2,189 $ 29,805 Fair Value Measurements December 31, 2016 Level 1 Level 2 Level 3 Total Certificates of deposit $ 7,275 $ — $ — $ 7,275 Money market funds 1,171 — — 1,171 U.S. treasuries 23,277 — — 23,277 Auction rate securities — — 2,046 2,046 $ 31,723 $ — $ 2,046 $ 33,769 |
| 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, 2016 $ 2,046 Total unrealized gains, excluding tax impact, included in other comprehensive loss 143 Balance at September 30, 2017 $ 2,189 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 | 1 Months Ended | 3 Months Ended | 9 Months Ended | |||
| Jul. 31, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | |
| 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 was required to maintain a letter of credit securing an amount equal to twelve months of the then current monthly installment of base rent for the original term of the lease for its facilities, which ended on August 31, 2017. | |||||
| Restricted cash | $ 192 | $ 192 | $ 3,311 | |||
| Renewal period for lease for lease beyond its expiration | 16 months | |||||
| Renewal lease agreement expiry date | Dec. 31, 2018 | |||||
| Secured letter of credit for the extended lease term | 200 | 200 | ||||
| Deferred contract costs | $ 9,600 | $ 9,600 | $ 5,500 | |||
| Common stock equivalents excluded from the calculation of diluted net income per share | 3,260 | 17,065 | 1,087 | 9,800 | ||
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, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | $ 183 | $ 213 | $ 611 | $ 804 |
| Research and development [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | 61 | 69 | 184 | 228 |
| Manufacturing and production [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | 30 | 25 | 95 | 89 |
| General and administrative [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
| Total stock-based compensation expense | $ 92 | $ 119 | $ 332 | $ 487 |
Stock-Based Compensation - Addi
| Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions | 9 Months Ended | |
| Sep. 30, 2017 | Sep. 30, 2016 | |
| Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
| Estimated value of stock-based awards, granted | $ 0.7 | $ 0.6 |
| Unrecognized compensation cost related to unvested options | $ 0.7 | |
| Unvested stock-based awards expected to be recognized, weighted-average period | 1 year 3 months 18 days | |
| Portion of stock-based awards granted from outstanding common shares | 5.10% | 3.10% |
Marketable Securities, Availa26
| Marketable Securities, Available for Sale - Summary of Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016 |
| Schedule of Available-for-sale Securities [Line Items] | ||
| Amortized Cost | $ 22,640 | $ 30,570 |
| Unrealized Gain | 0 | 0 |
| Unrealized Loss | 11 | 18 |
| Market Value | 22,629 | 30,552 |
| U.S. treasuries [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Amortized Cost | 18,495 | 23,295 |
| Unrealized Gain | 0 | 0 |
| Unrealized Loss | 11 | 18 |
| Market Value | 18,484 | 23,277 |
| Certificates of deposit [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Amortized Cost | 4,145 | 7,275 |
| Unrealized Gain | 0 | 0 |
| Unrealized Loss | 0 | 0 |
| Market Value | $ 4,145 | $ 7,275 |
Marketable Securities, Availa27
| Marketable Securities, Available for Sale - Additional Information (Detail) | 9 Months Ended |
| Sep. 30, 2017USD ($) | |
| 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, 2017 | Dec. 31, 2016 |
| Payables And Accruals [Abstract] | ||
| Employee compensation | $ 2,045 | $ 2,518 |
| Clinical trial accruals | 1,005 | 446 |
| Accounts payable | 610 | 326 |
| Deferred rent | 0 | 223 |
| Other accrued liabilities | 418 | 614 |
| Total accounts payable and accrued expenses | $ 4,078 | $ 4,127 |
Long-Term Investments - Additio
| Long-Term Investments - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2017 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | |
| 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 | 400,000 | $ 400,000 | ||
| Unrealized gains on auction rate securities | 95,000 | $ 109,000 | ||
| Cumulative unrealized gains | 400,000 | 400,000 | ||
| Carrying value of auction rate security | 2,189,000 | $ 2,189,000 | $ 2,046,000 | |
| Assumed interest rate | 3.085% | |||
| 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, 2017 | Dec. 31, 2016 |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | $ 29,805 | $ 33,769 |
| Certificates of deposit [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 4,145 | 7,275 |
| Money market funds [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 4,987 | 1,171 |
| U.S. treasuries [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 18,484 | 23,277 |
| Auction rate securities [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 2,189 | 2,046 |
| Level 1 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 27,616 | 31,723 |
| Level 1 [Member] | Certificates of deposit [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 4,145 | 7,275 |
| Level 1 [Member] | Money market funds [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 4,987 | 1,171 |
| Level 1 [Member] | U.S. treasuries [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 18,484 | 23,277 |
| Level 1 [Member] | Auction rate securities [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 2 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 2 [Member] | Certificates of deposit [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 2 [Member] | Money market funds [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 2 [Member] | U.S. treasuries [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 2 [Member] | Auction rate securities [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 3 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 2,189 | 2,046 |
| Level 3 [Member] | Certificates of deposit [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 3 [Member] | Money market funds [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 3 [Member] | U.S. treasuries [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | 0 | 0 |
| Level 3 [Member] | Auction rate securities [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Fair Value | $ 2,189 | $ 2,046 |
Fair Value Measurements - Addit
| Fair Value Measurements - Additional Information (Detail) - USD ($) | Sep. 30, 2017 | Dec. 31, 2016 |
| Level 2 [Member] | ||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Investments | $ 0 | $ 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, 2017USD ($) | |
| Fair Value Disclosures [Abstract] | |
| Balance at December 31, 2016 | $ 2,046 |
| Total unrealized gains, excluding tax impact, included in other comprehensive loss | 143 |
| Balance at September 30, 2017 | 2,189 |
| 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, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
| Revenue related to contract services | $ 3.1 | $ 2.3 | $ 9.1 | $ 9.8 |
| Recognized license revenue | $ 0.2 | $ 1.2 | ||
Stockholders' Equity - Addition
| Stockholders' Equity - Additional Information (Detail) - USD ($) | Aug. 01, 2016 | Sep. 30, 2017 | Sep. 30, 2017 | Oct. 31, 2016 |
| Stockholders Equity [Line Items] | ||||
| Private placement, share lock-up period | 2 years | |||
| At-The-Market Issuance Sales Agreement, maximum value of common stock to be issued | $ 10,000,000 | |||
| Shares of common stock issued during period under At-The-Market Issuance Sales Agreement | 320,983 | 450,883 | ||
| Gross proceeds from the sales agreement | $ 824,759 | $ 1,139,871 | ||
| 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] | ||||
| Number of shares of common stock sold under the sales agreement | 1,841,420 | |||
| Private placement, price per share | $ 4.24 | |||
| Private placement, gross proceeds | $ 7,800,000 | |||
| Private placement, closing date | Aug. 2, 2016 |
Related Party Transaction - Add
| Related Party Transaction - Additional Information (Detail) - USD ($) | Apr. 04, 2017 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 |
| Related Party Transaction [Line Items] | |||||
| Contract revenue | $ 3,188,000 | $ 2,310,000 | $ 9,458,000 | $ 10,028,000 | |
| Research Collaboration Agreement [Member] | AnGes MG, Inc [Member] | |||||
| Related Party Transaction [Line Items] | |||||
| Percentage of common stock outstanding | 18.60% | ||||
| Non- refundable amount receivable under research collaboration agreement | $ 750,000 | ||||
| Contract revenue | $ 400,000 |