Document and Entity Information
Document and Entity Information - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2015 | Mar. 01, 2016 | Jun. 30, 2015 | |
Document And Entity Information [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2015 | ||
Document Fiscal Year Focus | 2,015 | ||
Document Fiscal Period Focus | FY | ||
Trading Symbol | CNAT | ||
Entity Registrant Name | Conatus Pharmaceuticals Inc. | ||
Entity Central Index Key | 1,383,701 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Filer Category | Accelerated Filer | ||
Entity Common Stock, Shares Outstanding | 20,809,170 | ||
Entity Public Float | $ 75.2 |
Balance Sheets
Balance Sheets - USD ($) | Dec. 31, 2015 | Dec. 31, 2014 |
Current assets: | ||
Cash and cash equivalents | $ 13,876,090 | $ 9,912,674 |
Marketable securities | 22,632,019 | 27,159,272 |
Prepaid and other current assets | 1,982,031 | 796,818 |
Total current assets | 38,490,140 | 37,868,764 |
Property and equipment, net | 344,734 | 237,066 |
Other assets | 892,394 | 342,051 |
Total assets | 39,727,268 | 38,447,881 |
Current liabilities: | ||
Accounts payable and accrued expenses | 2,545,894 | 3,003,612 |
Accrued compensation | 1,436,804 | 1,171,621 |
Total current liabilities | 3,982,698 | 4,175,233 |
Note payable | 1,000,000 | 1,000,000 |
Deferred rent | $ 204,224 | $ 58,699 |
Stockholders’ equity: | ||
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding | ||
Common stock, $0.0001 par value; 200,000,000 shares authorized; 19,877,857 shares issued and 19,845,611 shares outstanding, excluding 32,246 shares subject to repurchase, at December 31, 2015; 15,695,834 shares issued and 15,560,614 shares outstanding, excluding 135,220 shares subject to repurchase, at December 31, 2014 | $ 1,984 | $ 1,556 |
Additional paid-in capital | 155,441,280 | 129,976,075 |
Accumulated other comprehensive loss | (3,907) | (13,297) |
Accumulated deficit | (120,899,011) | (96,750,385) |
Total stockholders’ equity | 34,540,346 | 33,213,949 |
Total liabilities and stockholders’ equity | $ 39,727,268 | $ 38,447,881 |
Balance Sheets (Parenthetical)
Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2015 | Dec. 31, 2014 |
Statement Of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.0001 | $ 0.0001 |
Preferred stock, shares authorized | 10,000,000 | 10,000,000 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized | 200,000,000 | 200,000,000 |
Common stock, shares issued | 19,877,857 | 15,695,834 |
Common stock, shares outstanding | 19,845,611 | 15,560,614 |
Common stock, shares subject to repurchase | 32,246 | 135,220 |
Statements of Operations and Co
Statements of Operations and Comprehensive Loss - USD ($) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Operating expenses: | |||
Research and development | $ 16,297,617 | $ 14,908,843 | $ 6,947,439 |
General and administrative | 7,833,085 | 7,379,339 | 4,650,807 |
Total operating expenses | 24,130,702 | 22,288,182 | 11,598,246 |
Other income (expense): | |||
Interest income | 67,885 | 57,616 | 22,144 |
Interest expense | (70,000) | (70,000) | (462,570) |
Other expense | (15,809) | (19,325) | (1,070) |
Other financing expense | (3,576,750) | ||
Total other expense | (17,924) | (31,709) | (4,018,246) |
Net loss | (24,148,626) | (22,319,891) | (15,616,492) |
Other comprehensive income (loss): | |||
Net unrealized gains (losses) on marketable securities | 9,390 | (24,794) | 10,946 |
Comprehensive loss | (24,139,236) | (22,344,685) | (15,605,546) |
Reconciliation of net loss to net loss applicable to common stockholders: | |||
Net loss | (24,148,626) | (22,319,891) | (15,616,492) |
Gain on extinguishment of convertible preferred stock | 11,491,043 | ||
Deemed distribution from promissory note issuance | (474,561) | ||
Net loss applicable to common stockholders | $ (24,148,626) | $ (22,319,891) | $ (4,600,010) |
Net loss per share applicable to common stockholders, basic and diluted | $ (1.30) | $ (1.44) | $ (0.63) |
Weighted average shares outstanding used in computing net loss per share applicable to common stockholders, basic and diluted | 18,617,537 | 15,478,999 | 7,358,201 |
Consolidated Statements of Conv
Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) | Total | Series A Warrants [Member] | Series B Warrants [Member] | Preferred Stock [Member]Series A Preferred Stock [Member] | Preferred Stock [Member]Series B Preferred Stock [Member] | Common Stock [Member] | Common Stock [Member]Series A Warrants [Member] | Additional Paid-in Capital [Member] | Additional Paid-in Capital [Member]Series A Warrants [Member] | Additional Paid-in Capital [Member]Series B Warrants [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Accumulated Deficit [Member] |
Beginning balance at Dec. 31, 2012 | $ (58,335,871) | $ 32,208,532 | $ 31,699,840 | $ 105 | $ 470,982 | $ 551 | $ (58,807,509) | |||||
Beginning balance, shares at Dec. 31, 2012 | 42,494,218 | 36,417,224 | 1,052,606 | |||||||||
Vesting of early exercise of employee stock options | 5,826 | $ 9 | 5,817 | |||||||||
Vesting of early exercise of employee stock options, shares | 92,561 | |||||||||||
Issuance of common stock upon exercise of stock options | $ 273 | $ 1 | 272 | |||||||||
Issuance of common stock upon exercise of stock options, shares | 174,447 | 3,030 | ||||||||||
Share-based compensation | $ 257,451 | 257,451 | ||||||||||
Investment in Idun Pharmaceuticals, Inc. | (500,000) | (493,507) | (6,493) | |||||||||
Deemed distribution from bridge note issuance | (474,561) | (474,561) | ||||||||||
Issuance of common stock, net of offering costs | 58,608,454 | $ 600 | 58,607,854 | |||||||||
Issuance of common stock, net of offering costs, shares | 6,000,000 | |||||||||||
Conversion of warrants to common stock | $ 3,083,549 | $ 1,159,659 | $ 28 | $ 3,083,521 | $ 1,159,659 | |||||||
Conversion of warrants to common stock, shares | 280,675 | |||||||||||
Conversion of preferred stock to common stock | 63,908,235 | $ (32,208,532) | $ (31,699,840) | $ 787 | 63,907,448 | |||||||
Conversion of preferred stock to common stock, shares | (42,494,218) | (36,417,224) | 7,865,722 | |||||||||
Conversion of notes payable and interest to common stock | 1,011,481 | $ 9 | 1,011,472 | |||||||||
Conversion of notes payable and interest to common stock, shares | 91,948 | |||||||||||
Net loss | (15,616,492) | (15,616,492) | ||||||||||
Unrealized gain (loss) on marketable securities | 10,946 | 10,946 | ||||||||||
Ending balance at Dec. 31, 2013 | 53,118,950 | $ 1,539 | 127,536,408 | 11,497 | (74,430,494) | |||||||
Ending balance, shares at Dec. 31, 2013 | 15,386,542 | |||||||||||
Vesting of early exercise of employee stock options | 20,602 | $ 10 | 20,592 | |||||||||
Vesting of early exercise of employee stock options, shares | 93,016 | |||||||||||
Issuance of common stock upon exercise of stock options | $ 88,422 | $ 7 | 88,415 | |||||||||
Issuance of common stock upon exercise of stock options, shares | 81,056 | 81,056 | ||||||||||
Share-based compensation | $ 2,330,660 | 2,330,660 | ||||||||||
Net loss | (22,319,891) | (22,319,891) | ||||||||||
Unrealized gain (loss) on marketable securities | (24,794) | (24,794) | ||||||||||
Ending balance at Dec. 31, 2014 | 33,213,949 | $ 1,556 | 129,976,075 | (13,297) | (96,750,385) | |||||||
Ending balance, shares at Dec. 31, 2014 | 15,560,614 | |||||||||||
Vesting of early exercise of employee stock options | 24,404 | $ 9 | 24,395 | |||||||||
Vesting of early exercise of employee stock options, shares | 71,249 | |||||||||||
Issuance of common stock upon exercise of stock options | $ 19,212 | 19,212 | ||||||||||
Issuance of common stock upon exercise of stock options, shares | 21,029 | 21,029 | ||||||||||
Issuance of common stock for employee stock purchase plan | $ 65,523 | $ 2 | 65,521 | |||||||||
Issuance of common stock for employee stock purchase plan, shares | 17,914 | |||||||||||
Share-based compensation | 3,315,943 | 3,315,943 | ||||||||||
Issuance of common stock, net of offering costs | 22,040,551 | $ 417 | 22,040,134 | |||||||||
Issuance of common stock, net of offering costs, shares | 4,174,805 | |||||||||||
Net loss | (24,148,626) | (24,148,626) | ||||||||||
Unrealized gain (loss) on marketable securities | 9,390 | 9,390 | ||||||||||
Ending balance at Dec. 31, 2015 | $ 34,540,346 | $ 1,984 | $ 155,441,280 | $ (3,907) | $ (120,899,011) | |||||||
Ending balance, shares at Dec. 31, 2015 | 19,845,611 |
Statements of Cash Flows
Statements of Cash Flows - USD ($) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Operating activities | |||
Net loss | $ (24,148,626) | $ (22,319,891) | $ (15,616,492) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation | 67,856 | 38,258 | 10,446 |
Stock-based compensation expense | 3,315,943 | 2,330,660 | 257,451 |
Noncash other financing expense | 3,618,206 | ||
Amortization of premium on marketable securities | 328,479 | 577,158 | 199,182 |
Changes in operating assets and liabilities: | |||
Prepaid and other current assets | (1,185,213) | (251,314) | (469,320) |
Other assets | (798,754) | (62,981) | |
Accounts payable and accrued expenses | (581,218) | 1,499,601 | 407,089 |
Accrued compensation | 289,587 | (130,345) | 961,721 |
Deferred rent | 165,761 | 58,699 | |
Net cash used in operating activities | (22,546,185) | (18,260,155) | (10,631,717) |
Investing activities | |||
Maturities of marketable securities | 62,574,000 | 54,072,000 | 4,725,000 |
Purchase of marketable securities | (58,365,836) | (29,639,190) | (53,117,797) |
Capital expenditures | (88,524) | (242,681) | (3,910) |
Net cash provided by (used in) investing activities | 4,119,640 | 24,190,129 | (48,396,707) |
Financing activities | |||
Issuance of promissory notes | 1,001,439 | ||
Distribution to wholly owned subsidiary in connection with spin-off of Idun Pharmaceuticals, Inc. | (500,000) | ||
Deferred public offering costs | (264,675) | ||
Proceeds from issuance of common stock, net of offering costs | 22,305,226 | 58,608,454 | |
Proceeds from stock issuances under employee stock purchase plan and exercise of stock options | 84,735 | 88,422 | 41,393 |
Net cash provided by (used in) financing activities | 22,389,961 | (176,253) | 59,151,286 |
Net increase in cash and cash equivalents | 3,963,416 | 5,753,721 | 122,862 |
Cash and cash equivalents at beginning of period | 9,912,674 | 4,158,953 | 4,036,091 |
Cash and cash equivalents at end of period | 13,876,090 | 9,912,674 | 4,158,953 |
Supplemental disclosure of cash flow information: | |||
Cash paid for interest | 70,000 | $ 70,000 | 88,583 |
Supplemental schedule of noncash investing and financing activities: | |||
Purchases of property and equipment included in accounts payable | $ 87,000 | ||
Conversion of notes payable for common stock | 1,001,439 | ||
Issuance of warrants in conjunction with debt | $ 625,792 |
Organization and Basis of Prese
Organization and Basis of Presentation | 12 Months Ended |
Dec. 31, 2015 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Organization and Basis of Presentation | 1. Organization and Basis of Presentation Conatus Pharmaceuticals Inc. (the Company) was incorporated in the state of Delaware on July 13, 2005. The Company is a biotechnology company focused on the development and commercialization of novel medicines to treat liver disease. As of December 31, 2015, the Company has devoted substantially all of its efforts to product development and has not realized revenues from its planned principal operations. The Company has a limited operating history, and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses since its inception and, as of December 31, 2015, had an accumulated deficit of $120.9 million. The Company expects to continue to incur net losses for at least the next several years. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. If the Company is unable to generate revenues adequate to support its cost structure, the Company may need to raise additional equity or debt financing. As of December 31, 2015, the Company had cash, cash equivalents and marketable securities of $36.5 million and working capital of $34.5 million. In July 2013, the Company implemented a 1-for-8.25 reverse stock split of its outstanding common stock. The accompanying financial statements give effect to the reverse split for all periods presented. In July 2013, the Company completed its initial public offering (IPO) of 6,000,000 shares of common stock at an offering price of $11.00 per share. The Company received net proceeds of $58.6 million, after deducting underwriting discounts and commissions and offering-related transaction costs. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2015 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash. Additionally, the Company established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity from the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include cash in readily available checking and money market accounts. Marketable Securities The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ equity (deficit). The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. The Company invests its excess cash balances primarily in corporate debt securities and money market funds with strong credit ratings. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses for the years ended December 31, 2015, 2014 and 2013. At each balance sheet date, the Company assesses available-for-sale securities in an unrealized loss position to determine whether the unrealized loss is other-than-temporary. The Company considers factors including: the significance of the decline in value compared to the cost basis, underlying factors contributing to a decline in the prices of securities in a single asset class, the length of time the market value of the security has been less than its cost basis, the security’s relative performance versus its peers, sector or asset class, expected market volatility and the market and economy in general. When the Company determines that a decline in the fair value below its cost basis is other-than-temporary, the Company recognizes an impairment loss in the year in which the other-than-temporary decline occurred. There have been no other-than-temporary declines in the value of marketable securities for the years ended December 31, 2015, 2014 and 2013, as it is more likely than not the Company will hold the securities until maturity or a recovery of the cost basis. Fair Value of Financial Instruments The carrying amounts of prepaid and other current assets, accounts payable and accrued expenses are reasonable estimates of their fair value because of the short maturity of these items. Property and Equipment Property and equipment, which consists of furniture and fixtures, computers and office equipment and leasehold improvements, are stated at cost and depreciated over the estimated useful lives of the assets (three to five years) using the straight-line method. Leasehold improvements are amortized over the shorter of their estimated useful lives or the lease term. Long-Lived Assets The Company regularly reviews the carrying value and estimated lives of all of its long-lived assets, including property and equipment, to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. The determinants used for this evaluation include management’s estimate of the asset’s ability to generate positive income from operations and positive cash flow in future periods, as well as the strategic significance of the assets to the Company’s business objective. Should an impairment exist, the impairment loss would be measured based on the excess of the carrying amount of the asset’s fair value. The Company has not recognized any impairment losses through December 31, 2015. Research and Development Expenses All research and development costs are expensed as incurred. Income Taxes The Company’s policy related to accounting for uncertainty in income taxes prescribes a recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. As of December 31, 2015, there are no unrecognized tax benefits included in the balance sheet that would, if recognized, affect the Company’s effective tax rate. The Company has not recognized interest and penalties in the balance sheets or statements of operations and comprehensive loss. The Company is subject to U.S. and California taxation. As of December 31, 2015, the Company’s tax years beginning 2005 to date are subject to examination by taxing authorities. Stock-Based Compensation Stock-based compensation expense for stock option grants under the Company’s stock option plans is recorded at the estimated fair value of the award as of the grant date and is recognized as expense on a straight-line basis over the requisite service period of the stock-based award. The fair value is estimated using the Black-Scholes model with the assumptions noted in the following table. The expected life of stock options is based on the simplified method described in the Securities and Exchange Commission (SEC) Staff Accounting Bulletin No. 107. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The risk-free interest rate is based on the average yield of five- and seven-year U.S. Treasury Bills as of the valuation date. Year Ended December 31, 2015 2014 2013 Assumptions Risk-free interest rate 1.54% - 1.94% 1.69% - 2.10% 0.95% - 1.81% Expected dividend yield 0% 0% 0% Expected volatility 72% - 89% 78% - 105% 69% - 79% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 6.0 - 6.1 Stock-based compensation expense for employee stock purchases under the Company’s 2013 Employee Stock Purchase Plan (the ESPP) is recorded at the estimated fair value of the purchase as of the plan enrollment date and is recognized as expense on a straight-line basis over the applicable six-month ESPP offering period. The fair value is estimated using the Black-Scholes model with inputs that include the applicable risk-free interest rate, expected dividend yield, expected volatility and expected term. The Company recorded stock-based compensation of $3.3 million, $2.3 million and $0.3 million for the years ended December 31, 2015, 2014 and 2013, respectively. Unrecognized compensation expense at December 31, 2015 was $6.3 million, which is expected to be recognized over a weighted-average vesting term of 2.4 years. Convertible Preferred Stock Warrant Liability The Company had issued freestanding warrants exercisable to purchase shares of its Series A and Series B convertible preferred stock. These warrants were classified as a liability in the balance sheets prior to the completion of the IPO, as the terms for redemption of the underlying security were outside the Company’s control. The Series A convertible preferred stock warrants were recorded at fair value using the Black-Scholes model. The Series B convertible preferred stock warrants were recorded at fair value using a Monte Carlo model. The fair value of all warrants, except as noted below, was remeasured at each financial reporting date with any changes in fair value being recognized in other financing income (expense), a component of other income (expense), in the accompanying statements of operations and comprehensive loss. The Company ceased the remeasurement of the fair value upon exercise of the Series A warrants and the Series B warrants becoming exercisable for shares of common stock, immediately prior to the completion of the Company’s IPO in July 2013. Comprehensive Loss The Company is required to report all components of comprehensive loss, including net loss, in the financial statements in the period in which they are recognized. Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from nonowner sources, including unrealized gains and losses on marketable securities. Comprehensive gains (losses) have been reflected in the statements of operations and comprehensive loss for all periods presented. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is used in making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating primarily in the United States. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of common shares and common share equivalents outstanding for the period. Common stock equivalents are only included when their effect is dilutive. The Company’s potentially dilutive securities, which include warrants to purchase common stock, outstanding stock options under the Company’s stock option plans, common stock subject to repurchase by the Company and potential shares to be purchased under the ESPP, have been excluded from the computation of diluted net loss per share in the periods in which they would be anti-dilutive. For all periods presented, there is no difference in the number of shares used to compute basic and diluted shares outstanding due to the Company’s net loss position. The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive. December 31, 2015 2014 2013 Warrants to purchase common stock 149,704 149,704 149,704 Common stock options issued and outstanding 2,464,849 1,859,034 790,590 Common stock subject to repurchase 32,246 135,220 233,337 ESPP shares pending issuance 5,103 2,175 — Total 2,651,902 2,146,133 1,173,631 Recent Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2015 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined 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. 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. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Includes financial instruments for which quoted market prices for identical instruments are available in active markets. Level 2: Includes financial instruments for which there are inputs other than quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets with insufficient volume or infrequent transaction (less active markets) or model-driven valuations in which significant inputs are observable or can be derived principally from, or corroborated by, observable market data. Level 3: Includes financial instruments for which fair value is derived from valuation techniques in which one or more significant inputs are unobservable, including management’s own assumptions. Below is a summary of assets and liabilities measured at fair value as of December 31, 2015 and 2014. Fair Value Measurements Using December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market funds $ 10,221,563 $ 10,221,563 $ — $ — Corporate debt securities 24,334,917 — 24,334,917 — Total assets $ 34,556,480 $ 10,221,563 $ 24,334,917 $ — Fair Value Measurements Using December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market funds $ 6,998,111 $ 6,998,111 $ — $ — Municipal bonds 70,000 — 70,000 — Corporate debt securities 28,589,331 — 28,589,331 — Total assets $ 35,657,442 $ 6,998,111 $ 28,659,331 $ — The Company’s marketable securities, consisting principally of debt securities, are classified as available-for-sale, are stated at fair value, and consist of Level 2 financial instruments in the fair value hierarchy. The Company determines the fair value of its debt security holdings based on pricing from a service provider. The service provider values the securities based on using market prices from a variety of industry-standard independent data providers. Such market prices may be quoted prices in active markets for identical assets (Level 1 inputs) or pricing determined using inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs), such as yield curve, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, broker and dealer quotes, as well as other relevant economic measures. The fair value of the convertible preferred stock warrant liability was determined based on “Level 3” inputs and utilized the Black-Scholes model for the Series A convertible preferred stock warrants. The Series B convertible preferred stock warrants utilized a Monte Carlo model. The warrant liabilities were marked to market before converting to equity at the IPO. The following table presents activity for the convertible preferred stock warrant liability measured at fair value using significant unobservable Level 3 inputs during the year ended December 31, 2013. Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3) Balance at December 31, 2012 $ 160,345 Issuance of preferred stock warrants 625,679 Changes in fair value reflected as other financing expense 3,457,184 Conversion to equity at IPO (4,243,208 ) Balance at December 31, 2013 $ — The fair value of the convertible promissory notes was determined based on “Level 3” inputs and valued the notes utilizing an estimated cost of debt from publicly available information on issuances of high yield fixed income securities issued by comparable companies. The Company concluded that a 15% discount rate was appropriate, resulting in an initial fair value for the notes of $970,000. The discount was accreted to interest expense through the Company’s IPO and was accreted completely at the IPO as the notes plus accrued Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3) Balance at December 31, 2012 $ — Issuance of convertible promissory notes 970,000 Accretion of debt discount to interest expense 31,439 Conversion to equity at IPO (1,001,439 ) Balance at December 31, 2013 $ — |
Marketable Securities
Marketable Securities | 12 Months Ended |
Dec. 31, 2015 | |
Investments Debt And Equity Securities [Abstract] | |
Marketable Securities | 4. Marketable Securities The Company invests its excess cash in money market funds and debt instruments of financial institutions, corporations, government sponsored entities and municipalities. The following tables summarize the Company’s marketable securities: As of December 31, 2015 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 22,635,926 $ 6,770 $ (10,677 ) $ 22,632,019 Total $ 22,635,926 $ 6,770 $ (10,677 ) $ 22,632,019 As of December 31, 2014 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 25,795,008 $ 1,137 $ (9,223 ) $ 25,786,922 Corporate debt securities 1 - 2 1,307,561 — (5,211 ) 1,302,350 Municipal bonds 1 or less 70,000 — — 70,000 Total $ 27,172,569 $ 1,137 $ (14,434 ) $ 27,159,272 |
Property and Equipment
Property and Equipment | 12 Months Ended |
Dec. 31, 2015 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment | 5. Property and Equipment Property and equipment consist of the following: December 31, 2015 2014 Furniture and fixtures $ 326,788 $ 239,788 Computer equipment and office equipment 170,946 162,921 Leasehold improvements 142,032 61,533 639,766 464,242 Less accumulated depreciation and amortization (295,032 ) (227,176 ) Total $ 344,734 $ 237,066 Depreciation expense related to property and equipment was $67,856, $38,258 and $10,446 for the years ended December 31, 2015, 2014 and 2013, respectively. |
Notes Payable
Notes Payable | 12 Months Ended |
Dec. 31, 2015 | |
Debt Disclosure [Abstract] | |
Notes Payable | 6. Notes Payable In July 2010, the Company entered into a $1.0 million promissory note payable to Pfizer Inc. (Pfizer). The note bears interest at 7% per annum, which is paid quarterly, and matures on July 29, 2020. The note payable prohibits the Company from paying cash dividends and is subject to acceleration upon specified events of default as defined in the agreement including the failure to notify Pfizer of certain material adverse events. In July 2013, the note payable to Pfizer was amended to become convertible into shares of the Company’s common stock following the completion of the IPO, at the option of the holder, at a price per share equal to the fair market value of the common stock on the date of conversion. In May 2013, the Company entered into a note and warrant purchase agreement with certain existing investors pursuant to which it sold, in a private placement, an aggregate of $1.0 million of convertible promissory notes (the 2013 Notes) and issued warrants exercisable to purchase 1,124,026 shares of Series B Preferred Stock (the 2013 Warrants). The 2013 Notes accrued interest at a rate of 6% per annum and were due and payable on the earlier of (1) any date after November 30, 2013 upon which holders of 75% of the outstanding principal amount of all such 2013 Notes demand repayment, or (2) the occurrence of a change of control of the Company, subject in each case to their earlier conversion in the event the Company completed a qualified initial public offering or private placement of debt and/or equity. The 2013 Notes did not provide for any potential adjustments to the stated conversion rates other than in the event of stock splits, stock dividends and recapitalizations. The conversion of the 2013 Notes in the event of a qualified initial public offering or private placement of equity was deemed to be the predominant settlement mechanism. As this predominant settlement mechanism provided for the settlement of a fixed monetary amount in a variable number of equity instruments, the Company concluded that it was appropriate to recognize the 2013 Notes at fair value. The Company valued the 2013 Notes utilizing an estimated cost of debt from publicly available information on issuances of high yield fixed income securities issued by comparable companies. The Company concluded that a 15% discount rate was appropriate, resulting in an initial fair value for the 2013 Notes of $970,000. Upon completion of the IPO, the 2013 Notes plus accrued interest automatically converted into 91,948 shares of common stock. The 2013 Warrants were exercisable for an aggregate of 1,124,026 shares of Series B Preferred Stock at an exercise price of $0.90 per share. Upon completion of the IPO, the 2013 Warrants became exercisable for an aggregate of 136,236 shares of common stock at an exercise price of $7.43 per share. The 2013 Warrants will expire on May 30, 2018. The 2013 Warrants were initially accounted for as liabilities with changes in fair value recognized within the statements of operations and comprehensive loss. The Company determined that the initial value of the 2013 Warrants was $506,000. The 2013 Warrants were valued utilizing a Monte Carlo simulation of various weighted scenarios. Following the IPO, the 2013 Warrants were reclassified into equity at their fair value at the time of the completion of the IPO. The valuation at the issuance of the 2013 Notes and 2013 Warrants resulted in a deemed distribution in the amount of $474,561 accounted for as a reduction in net income applicable to common stockholders. In July 2013, the Company entered into a loan and security agreement, (the Credit Facility) with Oxford Finance LLC and Silicon Valley Bank (the Lenders). The Credit Facility provided funding for an aggregate principal amount of up to $15.0 million. The first term loan of the Credit Facility was funded in July 2013 in the amount of $1.0 million. On September 25, 2013, the Company prepaid the outstanding advances under the Credit Facility. Accordingly, the Credit Facility was terminated on September 25, 2013. In connection with the funding of the first term loan under the Credit Facility, the Company issued warrants to the Lenders to purchase up to an aggregate of 111,112 shares of Series B convertible preferred stock at an exercise price of $0.90 per share (Lender Warrants). The Lender Warrants will expire on July 3, 2023. The Lender Warrants were initially accounted for as liabilities with the changes in fair value recognized within the statements of operations and comprehensive loss. The Lender Warrants were initially valued at $119,679, and such amount was recognized as additional expense. Upon completion of the IPO, the Lender Warrants became exercisable for an aggregate of 13,468 shares of common stock at an exercise price of $7.43 per share. Following the IPO, the Lender Warrants were reclassified into equity at their fair value at the time of the completion of the IPO. |
Convertible Preferred Stock and
Convertible Preferred Stock and Stockholders' Equity (Deficit) | 12 Months Ended |
Dec. 31, 2015 | |
Equity [Abstract] | |
Convertible Preferred Stock and Stockholders' Equity (Deficit) | 7. Convertible Preferred Stock and Stockholders’ Equity (Deficit) Common Stock In July 2013, the Company implemented a 1-for-8.25 reverse stock split of its outstanding common stock. The accompanying financial statements give effect to the reverse split for all periods presented. In July 2013, the Company completed the IPO of 6,000,000 shares of common stock at an offering price of $11.00 per share. The Company received net proceeds of $58.6 million, after deducting underwriting discounts and commissions and offering-related transaction costs. In August 2014, the Company entered into an At Market Issuance Sales Agreement (the Sales Agreement) with MLV & Co. LLC (MLV), pursuant to which the Company may sell from time to time, at its option, up to an aggregate of $50.0 million of shares of its common stock through MLV, as sales agent. Sales of the Company’s common stock made pursuant to the Sales Agreement are made on The NASDAQ Global Market (Nasdaq) under the Company’s Registration Statement on Form S-3, filed with the SEC on August 14, 2014 and declared effective by the SEC on August 25, 2014, by means of ordinary brokers’ transactions at market prices. Additionally, under the terms of the Sales Agreement, the Company may also sell shares of its common stock through MLV, on Nasdaq or otherwise, at negotiated prices or at prices related to the prevailing market price. Under the terms of the Sales Agreement, MLV may not engage in any proprietary trading or trading as principal for MLV’s own account. MLV has agreed to use commercially reasonable efforts consistent with its normal trading and sales practices to sell the Company’s common stock from time to time, based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company has agreed to pay a commission rate equal to up to 3% of the gross sales price per share sold. The Company has also agreed to provide MLV with customary indemnification and contribution rights. During the year ended December 31, 2015, the Company sold 149,805 shares of its common stock pursuant to the Sales Agreement at a weighted average price per share of $6.05 and received net proceeds of $0.6 million, after deducting offering-related transaction costs and commissions. At December 31, 2014, the Company had incurred legal and accounting transaction costs of $0.2 million in connection with the commencement of the Sales Agreement, which were recorded in other assets on the balance sheet and were reclassified to additional paid-in capital upon the first sale of common stock pursuant to the Sales Agreement. In April 2015, the Company completed a public offering of 4,025,000 shares of its common stock at a public offering price of $5.75 per share. The shares were registered pursuant to the Registration Statement on Form S-3 filed on August 14, 2014. The Company received net proceeds of $21.4 million, after deducting underwriting discounts and commissions and offering-related transaction costs. At December 31, 2014, the Company had incurred legal and accounting transaction costs of $0.1 million in connection with the public offering, which were recorded in other assets on the balance sheet and were reclassified to additional paid-in capital upon completion of the public offering. Convertible Preferred Stock On May 30, 2013, 15,576,789 shares of the Company’s convertible preferred stock were converted into 1,557,678 shares of common stock (188,808 shares on a post-reverse split basis) as a result of one preferred stock investor not purchasing a pro rata share of the 2013 Notes. As a result of this transaction, a gain on the extinguishment of preferred stock was recognized as income applicable to common stockholders and an addition to additional paid-in capital in the amount of $11,491,043, which represented the difference between the carrying value of the 15,576,789 shares of convertible preferred stock and the fair value of the 188,808 shares of common stock. In connection with the IPO in July 2013, all 63,334,653 outstanding shares of convertible preferred stock converted into an aggregate of 7,676,914 shares of common stock. Warrants The Company issued warrants to purchase a total of 2,333,320 shares of Series A Preferred Stock in conjunction with a convertible bridge financing in 2010 and issued the 2013 Warrants and Lender Warrants in Stock Options The Company adopted an Equity Incentive Plan in 2006 (the 2006 Plan) under which 1,030,303 shares of common stock were reserved for issuance to employees, nonemployee directors and consultants of the Company. In July 2013, the Company adopted an Incentive Award Plan (the 2013 Plan), which provides for the grant of incentive stock options, nonstatutory stock options, rights to purchase restricted stock, stock appreciation rights, dividend equivalents, stock payments and restricted stock units to eligible recipients. Recipients of incentive stock options shall be eligible to purchase shares of the Company’s common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The maximum term of options granted under the 2013 Plan is ten years. Except for annual grants to non-employee directors, which vest one year from the grant date, options generally vest 25% on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining three years. Pursuant to the 2013 Plan, the Company’s management is authorized to grant stock options to the Company’s employees, directors and consultants. The number of shares available for future grant under the 2013 Plan will automatically increase each year by an amount equal to the least of (1) 1,000,000 shares of the Company’s common stock, (2) 5% of the outstanding shares of the Company’s common stock as of the last day of the Company’s immediately preceding fiscal year, or (3) such other amount as the Company’s board of directors may determine. Shares that remain available, that expire or otherwise terminate without having been exercised in full, and unvested shares that are forfeited to or repurchased by the Company under the 2006 Plan will roll into the 2013 Plan. As of December 31, 2015, 593,531 options remain available for future grant under the 2013 Plan. The following table summarizes the Company’s stock option activity under all stock option plans for the three years ended December 31, 2015. Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Outstanding at December 31, 2012 690,223 $ 0.80 Granted 316,935 9.44 Exercised (174,447 ) 0.24 Cancelled (42,121 ) 7.86 Outstanding at December 31, 2013 790,590 4.01 Granted 1,212,000 8.41 Exercised (81,056 ) 1.10 Cancelled (62,500 ) 9.09 Outstanding at December 31, 2014 1,859,034 6.84 Granted 822,250 6.03 Exercised (21,029 ) 1.04 Cancelled (195,406 ) 7.79 Outstanding at December 31, 2015 2,464,849 $ 6.54 7.87 Vested or expected to vest at December 31, 2015 2,288,775 $ 6.58 7.77 Exercisable at December 31, 2015 1,071,325 $ 5.75 6.66 The weighted-average fair value of options granted for the years ended December 31, 2015, 2014 and 2013 were $4.31, $6.77 and $6.31, respectively. The total intrinsic value of stock options exercised during the years ended December 31, 2015, 2014 and 2013 were $0.1 million, $0.5 million and $1.1 million, respectively. Unvested shares from the early exercise of options are subject to repurchase by the Company at the lower of the original issue price or fair value. There were 32,246 shares subject to repurchase at December 31, 2015. The Company recorded a related liability for the early exercise of options totaling $2,902 and $27,306 at December 31, 2015 and 2014, respectively, which is included in accrued compensation on the balance sheets. At December 31, 2015, the intrinsic value of options outstanding, vested or expected to vest, and exercisable were $0.8 million, $0.8 million and $0.8 million, respectively. Employee Stock Purchase Plan In July 2013, the Company adopted the ESPP, which permits participants to contribute up to 20% of their eligible compensation during defined rolling six-month periods to purchase the Company’s common stock. The purchase price of the shares will be 85% of the lower of the fair market value of the Company’s common stock on the first day of trading of the offering period or on the applicable purchase date. The ESPP was activated in November 2014. The Company issued 17,914 and 0 shares of common stock under the ESPP for the years ended December 31, 2015 and 2014, respectively. The Company had an outstanding liability of $15,789 and $13,167 at December 31, 2015 and 2014, respectively, which is included in accounts payable and accrued expenses on the balance sheets, for employee contributions to the ESPP for shares pending issuance at the end of the offering period. Common Stock Reserved for Future Issuance The following shares of common stock were reserved for future issuance at December 31, 2015 and 2014: December 31, 2015 December 31, 2014 Warrants to purchase common stock 149,704 149,704 Common stock options issued and outstanding 2,464,849 1,859,034 Common stock authorized for future option grants 593,531 403,859 Common stock authorized for the ESPP 432,086 300,000 Total 3,640,170 2,712,597 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 8. Income Taxes The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by the federal and state jurisdictions where applicable. There are currently no pending income tax examinations. The Company’s tax years for 2005 and forward are subject to examination by the federal and California tax authorities due to the carryforward of unutilized net operating losses and research and development credits. Pursuant to Internal Revenue Code (IRC) Sections 382 and 383, annual use of the Company’s net operating loss and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has not completed an IRC Section 382/383 analysis regarding the limitation of net operating loss and research and development credit carryforwards. The Company does not expect this analysis to be completed within the next 12 months. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact the Company’s effective tax rate. Significant components of the Company’s deferred tax assets at December 31, 2015 and 2014 are shown below: December 31, 2015 2014 Deferred tax assets Net operating loss carryovers $ 33,007,000 $ 25,258,000 Research and development tax credits 3,585,000 2,017,000 Intangibles 922,000 1,090,000 Stock options 1,614,000 744,000 Compensation 553,000 423,000 Other 212,000 100,000 Total gross deferred tax assets 39,893,000 29,632,000 Less valuation allowance (39,893,000 ) (29,632,000 ) Net deferred tax assets $ — $ — A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 31, 2015, 2014 and 2013 is as follows: December 31, 2015 2014 2013 Statutory rate 34.00 % 34.00 % 34.00 % State tax, net of federal benefit 5.83 % 5.83 % 5.83 % Valuation allowance (42.48 )% (39.85 )% (7.75 )% Gain on distribution of subsidiary 0.00 % 0.00 % (24.49 )% Nondeductible interest 0.00 % 0.00 % (9.08 )% Other 2.65 % 0.02 % 1.49 % Effective tax rate — % — % — % At December 31, 2015, the Company has federal and state net operating loss carryforwards of $83.3 million and $83.5 million, respectively. The federal and state loss carryforwards begin to expire in 2025 and 2016, respectively, unless previously utilized. The Company also has federal and state research credit carryforwards of $3.6 million and $1.3 million, respectively. The federal research credit carryforwards will begin expiring in 2026 unless previously utilized. The state research credit will carry forward indefinitely. The change in the valuation allowance is an increase of $10.3 million and an increase of $8.9 million for the years ended December 31, 2015 and 2014. The Company removed the net operating losses and research credits attributable to Idun Pharmaceuticals, Inc. (Idun). The stock of Idun was distributed to the Company’s stockholders in January 2013. The Company accounts for income taxes in accordance with Accounting Standards Codification 740-10, Accounting for Uncertainty in Income Tax. The impact of an uncertain income tax position is recognized at the largest amount that is “more likely than not” to be sustained upon audit by the relevant taxing authority. An uncertain tax position will not be recognized if it has less than a 50% likelihood of being sustained. The following table summarizes the activity related to our unrecognized tax benefits: 2015 2014 2013 Balance at beginning of year $ 571,194 $ 457,106 $ — Additions based on tax positions related to the current year 337,862 141,866 97,412 Additions for tax positions of prior years 72,324 — 359,694 Reductions for tax positions of prior years — (27,778 ) — Settlement of tax audits — — — Reductions due to lapsed statute of limitations — — — Balance at end of year $ 981,380 $ 571,194 $ 457,106 The Company does not expect that the unrecognized tax benefits will change within 12 months of this reporting date. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact the Company’s effective tax rate. The Company’s policy is to recognize interest and penalties related to income tax matters in income tax expense. For the years ended December 31, 2015, 2014 and 2013, the Company has not recognized any interest or penalties related to income taxes. |
Employee Benefits
Employee Benefits | 12 Months Ended |
Dec. 31, 2015 | |
Postemployment Benefits [Abstract] | |
Employee Benefits | 9. Employee Benefits Effective December 4, 2006, the Company has a defined contribution 401(k) plan for its employees. Employees are eligible to participate in the plan beginning on the first day of employment. Under the terms of the plan, employees may make voluntary contributions as a percent of compensation. Effective January 1, 2007, |
Commitments
Commitments | 12 Months Ended |
Dec. 31, 2015 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments | 10. Commitments In February 2014, the Company entered into a noncancelable operating lease agreement (the Lease) for certain office space with a lease term from July 2014 through December 2019 with a renewal option for an additional five years. In May 2015, the Company entered into a first amendment to the Lease (the First Lease Amendment) for additional office space starting in September 2015 through September 2020. The First Lease Amendment also extended the term of the Lease to September 2020. The monthly base rent under the Lease and the First Lease Amendment will increase approximately 3% annually from $32,784 in 2015 to $39,268 in 2020. Future minimum payments under this noncancelable operating lease total $2.0 million at December 31, 2015. Rent expense was $339,053, $243,832 and $167,998 for the years ended December 31, 2015, 2014 and 2013, respectively. In July 2010, the Company entered into a stock purchase agreement with Pfizer, pursuant to which the Company acquired all of the outstanding stock of Idun. Under the agreement, the Company may be required to make payments to Pfizer totaling $18.0 million upon the achievement of specified regulatory milestones. |
Spin-off of Idun Pharmaceutical
Spin-off of Idun Pharmaceuticals, Inc. | 12 Months Ended |
Dec. 31, 2015 | |
Restructuring And Related Activities [Abstract] | |
Spin-off of Idun Pharmaceuticals, Inc. | 11. Spin-off of Idun Pharmaceuticals, Inc. In January 2013, the Company spun off its subsidiary Idun to the Company’s stockholders. Prior to the spin-off, rights relating to emricasan were distributed to the Company by Idun pursuant to a distribution agreement. The spin-off was conducted as a dividend of all of the outstanding capital stock of Idun to the Company’s stockholders. As a result, the Company no longer holds any capital stock of Idun. In connection with the spin-off, the Company contributed $0.5 million to Idun to provide for Idun’s initial working capital requirements. The assets remaining in Idun at the time of the spin-off consisted of cash, intellectual property rights and license and collaboration agreements unrelated to emricasan. Other than the cash of $0.5 million, none of the assets held by Idun had any historical carrying value at the time of the spin-off. As a result, the Company recognized a reduction in equity as a result of the spin-off of $0.5 million, representing the carrying value of Idun in the Company’s financial statements at the time of the spin-off. |
Quarterly Financial Data
Quarterly Financial Data | 12 Months Ended |
Dec. 31, 2015 | |
Quarterly Financial Information Disclosure [Abstract] | |
Quarterly Financial Data | 12. Quarterly Financial Data (unaudited) The following tables summarize the unaudited quarterly financial data for the last two fiscal years. 2015 First Quarter Second Quarter Third Quarter Fourth Quarter Total operating expenses $ 5,964,922 $ 6,064,479 $ 6,061,335 $ 6,039,966 Total other (expense) income (14,742 ) 7,225 (6,211 ) (4,196 ) Net loss (5,979,664 ) (6,057,254 ) (6,067,546 ) (6,044,162 ) Net loss per share, basic and diluted (1) (0.38 ) (0.31 ) (0.31 ) (0.30 ) 2014 First Quarter Second Quarter Third Quarter Fourth Quarter Total operating expenses $ 5,245,845 $ 5,304,756 $ 6,416,237 $ 5,321,344 Total other income (expense) 2,489 1,732 (20,923 ) (15,007 ) Net loss (5,243,356 ) (5,303,024 ) (6,437,160 ) (5,336,351 ) Net loss per share, basic and diluted (1) (0.34 ) (0.34 ) (0.42 ) (0.34 ) (1) |
Subsequent Events
Subsequent Events | 12 Months Ended |
Dec. 31, 2015 | |
Subsequent Events [Abstract] | |
Subsequent Events | 13. Subsequent Events Subsequent to the year ending December 31, 2015 through the date of this filing, the Company sold 930,101 shares of common stock pursuant to the Sales Agreement at an average price per share of $2.78 and received net proceeds of $2.6 million, after deducting offering related transaction costs and commissions. |
Summary of Significant Accoun20
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2015 | |
Accounting Policies [Abstract] | |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. |
Concentrations of Credit Risk | Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash. Additionally, the Company established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity. |
Cash and Cash Equivalents | Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity from the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include cash in readily available checking and money market accounts. |
Marketable Securities | Marketable Securities The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the statements of operations and comprehensive loss and as a separate component of stockholders’ equity (deficit). The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. The Company invests its excess cash balances primarily in corporate debt securities and money market funds with strong credit ratings. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses for the years ended December 31, 2015, 2014 and 2013. At each balance sheet date, the Company assesses available-for-sale securities in an unrealized loss position to determine whether the unrealized loss is other-than-temporary. The Company considers factors including: the significance of the decline in value compared to the cost basis, underlying factors contributing to a decline in the prices of securities in a single asset class, the length of time the market value of the security has been less than its cost basis, the security’s relative performance versus its peers, sector or asset class, expected market volatility and the market and economy in general. When the Company determines that a decline in the fair value below its cost basis is other-than-temporary, the Company recognizes an impairment loss in the year in which the other-than-temporary decline occurred. There have been no other-than-temporary declines in the value of marketable securities for the years ended December 31, 2015, 2014 and 2013, as it is more likely than not the Company will hold the securities until maturity or a recovery of the cost basis. |
Fair Value of Financial Instruments | Fair Value of Financial Instruments The carrying amounts of prepaid and other current assets, accounts payable and accrued expenses are reasonable estimates of their fair value because of the short maturity of these items. |
Property and Equipment | Property and Equipment Property and equipment, which consists of furniture and fixtures, computers and office equipment and leasehold improvements, are stated at cost and depreciated over the estimated useful lives of the assets (three to five years) using the straight-line method. Leasehold improvements are amortized over the shorter of their estimated useful lives or the lease term. |
Long-Lived Assets | Long-Lived Assets The Company regularly reviews the carrying value and estimated lives of all of its long-lived assets, including property and equipment, to determine whether indicators of impairment may exist which warrant adjustments to carrying values or estimated useful lives. The determinants used for this evaluation include management’s estimate of the asset’s ability to generate positive income from operations and positive cash flow in future periods, as well as the strategic significance of the assets to the Company’s business objective. Should an impairment exist, the impairment loss would be measured based on the excess of the carrying amount of the asset’s fair value. The Company has not recognized any impairment losses through December 31, 2015. |
Research and Development Expenses | Research and Development Expenses All research and development costs are expensed as incurred. |
Income Taxes | Income Taxes The Company’s policy related to accounting for uncertainty in income taxes prescribes a recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. As of December 31, 2015, there are no unrecognized tax benefits included in the balance sheet that would, if recognized, affect the Company’s effective tax rate. The Company has not recognized interest and penalties in the balance sheets or statements of operations and comprehensive loss. The Company is subject to U.S. and California taxation. As of December 31, 2015, the Company’s tax years beginning 2005 to date are subject to examination by taxing authorities. |
Stock-Based Compensation | Stock-Based Compensation Stock-based compensation expense for stock option grants under the Company’s stock option plans is recorded at the estimated fair value of the award as of the grant date and is recognized as expense on a straight-line basis over the requisite service period of the stock-based award. The fair value is estimated using the Black-Scholes model with the assumptions noted in the following table. The expected life of stock options is based on the simplified method described in the Securities and Exchange Commission (SEC) Staff Accounting Bulletin No. 107. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The risk-free interest rate is based on the average yield of five- and seven-year U.S. Treasury Bills as of the valuation date. Year Ended December 31, 2015 2014 2013 Assumptions Risk-free interest rate 1.54% - 1.94% 1.69% - 2.10% 0.95% - 1.81% Expected dividend yield 0% 0% 0% Expected volatility 72% - 89% 78% - 105% 69% - 79% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 6.0 - 6.1 Stock-based compensation expense for employee stock purchases under the Company’s 2013 Employee Stock Purchase Plan (the ESPP) is recorded at the estimated fair value of the purchase as of the plan enrollment date and is recognized as expense on a straight-line basis over the applicable six-month ESPP offering period. The fair value is estimated using the Black-Scholes model with inputs that include the applicable risk-free interest rate, expected dividend yield, expected volatility and expected term. The Company recorded stock-based compensation of $3.3 million, $2.3 million and $0.3 million for the years ended December 31, 2015, 2014 and 2013, respectively. Unrecognized compensation expense at December 31, 2015 was $6.3 million, which is expected to be recognized over a weighted-average vesting term of 2.4 years. |
Convertible Preferred Stock Warrant Liability | Convertible Preferred Stock Warrant Liability The Company had issued freestanding warrants exercisable to purchase shares of its Series A and Series B convertible preferred stock. These warrants were classified as a liability in the balance sheets prior to the completion of the IPO, as the terms for redemption of the underlying security were outside the Company’s control. The Series A convertible preferred stock warrants were recorded at fair value using the Black-Scholes model. The Series B convertible preferred stock warrants were recorded at fair value using a Monte Carlo model. The fair value of all warrants, except as noted below, was remeasured at each financial reporting date with any changes in fair value being recognized in other financing income (expense), a component of other income (expense), in the accompanying statements of operations and comprehensive loss. The Company ceased the remeasurement of the fair value upon exercise of the Series A warrants and the Series B warrants becoming exercisable for shares of common stock, immediately prior to the completion of the Company’s IPO in July 2013. |
Comprehensive Loss | Comprehensive Loss The Company is required to report all components of comprehensive loss, including net loss, in the financial statements in the period in which they are recognized. Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from nonowner sources, including unrealized gains and losses on marketable securities. Comprehensive gains (losses) have been reflected in the statements of operations and comprehensive loss for all periods presented. |
Segment Reporting | Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is used in making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating primarily in the United States. |
Net Loss Per Share | Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of common shares and common share equivalents outstanding for the period. Common stock equivalents are only included when their effect is dilutive. The Company’s potentially dilutive securities, which include warrants to purchase common stock, outstanding stock options under the Company’s stock option plans, common stock subject to repurchase by the Company and potential shares to be purchased under the ESPP, have been excluded from the computation of diluted net loss per share in the periods in which they would be anti-dilutive. For all periods presented, there is no difference in the number of shares used to compute basic and diluted shares outstanding due to the Company’s net loss position. The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive. December 31, 2015 2014 2013 Warrants to purchase common stock 149,704 149,704 149,704 Common stock options issued and outstanding 2,464,849 1,859,034 790,590 Common stock subject to repurchase 32,246 135,220 233,337 ESPP shares pending issuance 5,103 2,175 — Total 2,651,902 2,146,133 1,173,631 |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). |
Summary of Significant Accoun21
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Accounting Policies [Abstract] | |
Schedule of Black-Scholes Option Pricing Model Assumptions | The fair value is estimated using the Black-Scholes model with the assumptions noted in the following table. The expected life of stock options is based on the simplified method described in the Securities and Exchange Commission (SEC) Staff Accounting Bulletin No. 107. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The risk-free interest rate is based on the average yield of five- and seven-year U.S. Treasury Bills as of the valuation date. Year Ended December 31, 2015 2014 2013 Assumptions Risk-free interest rate 1.54% - 1.94% 1.69% - 2.10% 0.95% - 1.81% Expected dividend yield 0% 0% 0% Expected volatility 72% - 89% 78% - 105% 69% - 79% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 6.0 - 6.1 |
Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share | The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because to do so would be anti-dilutive. December 31, 2015 2014 2013 Warrants to purchase common stock 149,704 149,704 149,704 Common stock options issued and outstanding 2,464,849 1,859,034 790,590 Common stock subject to repurchase 32,246 135,220 233,337 ESPP shares pending issuance 5,103 2,175 — Total 2,651,902 2,146,133 1,173,631 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Summary of Assets and Liabilities Measured at Fair Value | Below is a summary of assets and liabilities measured at fair value as of December 31, 2015 and 2014. Fair Value Measurements Using December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market funds $ 10,221,563 $ 10,221,563 $ — $ — Corporate debt securities 24,334,917 — 24,334,917 — Total assets $ 34,556,480 $ 10,221,563 $ 24,334,917 $ — Fair Value Measurements Using December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Money market funds $ 6,998,111 $ 6,998,111 $ — $ — Municipal bonds 70,000 — 70,000 — Corporate debt securities 28,589,331 — 28,589,331 — Total assets $ 35,657,442 $ 6,998,111 $ 28,659,331 $ — |
Convertible promissory notes [Member] | |
Fair Value Measurements of Using Significant Unobservable Level 3 Inputs | The following table presents activity for the convertible promissory notes measured at fair value using significant unobservable Level 3 inputs during the year ended December 31, 2013. Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3) Balance at December 31, 2012 $ — Issuance of convertible promissory notes 970,000 Accretion of debt discount to interest expense 31,439 Conversion to equity at IPO (1,001,439 ) Balance at December 31, 2013 $ — |
Preferred stock warrant liability [Member] | |
Fair Value Measurements of Using Significant Unobservable Level 3 Inputs | The following table presents activity for the convertible preferred stock warrant liability measured at fair value using significant unobservable Level 3 inputs during the year ended December 31, 2013. Fair Value Measurements at Reporting Date Using Significant Unobservable Inputs (Level 3) Balance at December 31, 2012 $ 160,345 Issuance of preferred stock warrants 625,679 Changes in fair value reflected as other financing expense 3,457,184 Conversion to equity at IPO (4,243,208 ) Balance at December 31, 2013 $ — |
Marketable Securities (Tables)
Marketable Securities (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Investments Debt And Equity Securities [Abstract] | |
Summary of Marketable Securities | The Company invests its excess cash in money market funds and debt instruments of financial institutions, corporations, government sponsored entities and municipalities. The following tables summarize the Company’s marketable securities: As of December 31, 2015 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 22,635,926 $ 6,770 $ (10,677 ) $ 22,632,019 Total $ 22,635,926 $ 6,770 $ (10,677 ) $ 22,632,019 As of December 31, 2014 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 25,795,008 $ 1,137 $ (9,223 ) $ 25,786,922 Corporate debt securities 1 - 2 1,307,561 — (5,211 ) 1,302,350 Municipal bonds 1 or less 70,000 — — 70,000 Total $ 27,172,569 $ 1,137 $ (14,434 ) $ 27,159,272 |
Property and Equipment (Tables)
Property and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Property Plant And Equipment [Abstract] | |
Schedule of Property and Equipment | Property and equipment consist of the following: December 31, 2015 2014 Furniture and fixtures $ 326,788 $ 239,788 Computer equipment and office equipment 170,946 162,921 Leasehold improvements 142,032 61,533 639,766 464,242 Less accumulated depreciation and amortization (295,032 ) (227,176 ) Total $ 344,734 $ 237,066 |
Convertible Preferred Stock a25
Convertible Preferred Stock and Stockholders' Equity (Deficit) (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Equity [Abstract] | |
Summary of Stock Option Activity | The following table summarizes the Company’s stock option activity under all stock option plans for the three years ended December 31, 2015. Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Outstanding at December 31, 2012 690,223 $ 0.80 Granted 316,935 9.44 Exercised (174,447 ) 0.24 Cancelled (42,121 ) 7.86 Outstanding at December 31, 2013 790,590 4.01 Granted 1,212,000 8.41 Exercised (81,056 ) 1.10 Cancelled (62,500 ) 9.09 Outstanding at December 31, 2014 1,859,034 6.84 Granted 822,250 6.03 Exercised (21,029 ) 1.04 Cancelled (195,406 ) 7.79 Outstanding at December 31, 2015 2,464,849 $ 6.54 7.87 Vested or expected to vest at December 31, 2015 2,288,775 $ 6.58 7.77 Exercisable at December 31, 2015 1,071,325 $ 5.75 6.66 |
Summary of Common Stock Reserved for Future Issuance | The following shares of common stock were reserved for future issuance at December 31, 2015 and 2014: December 31, 2015 December 31, 2014 Warrants to purchase common stock 149,704 149,704 Common stock options issued and outstanding 2,464,849 1,859,034 Common stock authorized for future option grants 593,531 403,859 Common stock authorized for the ESPP 432,086 300,000 Total 3,640,170 2,712,597 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |
Components of Company's Deferred Tax Assets | Significant components of the Company’s deferred tax assets at December 31, 2015 and 2014 are shown below: December 31, 2015 2014 Deferred tax assets Net operating loss carryovers $ 33,007,000 $ 25,258,000 Research and development tax credits 3,585,000 2,017,000 Intangibles 922,000 1,090,000 Stock options 1,614,000 744,000 Compensation 553,000 423,000 Other 212,000 100,000 Total gross deferred tax assets 39,893,000 29,632,000 Less valuation allowance (39,893,000 ) (29,632,000 ) Net deferred tax assets $ — $ — |
Reconciliation of Statutory Tax Rates and Effective Tax Rates | A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 31, 2015, 2014 and 2013 is as follows: December 31, 2015 2014 2013 Statutory rate 34.00 % 34.00 % 34.00 % State tax, net of federal benefit 5.83 % 5.83 % 5.83 % Valuation allowance (42.48 )% (39.85 )% (7.75 )% Gain on distribution of subsidiary 0.00 % 0.00 % (24.49 )% Nondeductible interest 0.00 % 0.00 % (9.08 )% Other 2.65 % 0.02 % 1.49 % Effective tax rate — % — % — % |
Unrecognized Tax Benefits | The following table summarizes the activity related to our unrecognized tax benefits: 2015 2014 2013 Balance at beginning of year $ 571,194 $ 457,106 $ — Additions based on tax positions related to the current year 337,862 141,866 97,412 Additions for tax positions of prior years 72,324 — 359,694 Reductions for tax positions of prior years — (27,778 ) — Settlement of tax audits — — — Reductions due to lapsed statute of limitations — — — Balance at end of year $ 981,380 $ 571,194 $ 457,106 |
Quarterly Financial Data (Table
Quarterly Financial Data (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Quarterly Financial Information Disclosure [Abstract] | |
Summary of Quarterly Financial Data | The following tables summarize the unaudited quarterly financial data for the last two fiscal years. 2015 First Quarter Second Quarter Third Quarter Fourth Quarter Total operating expenses $ 5,964,922 $ 6,064,479 $ 6,061,335 $ 6,039,966 Total other (expense) income (14,742 ) 7,225 (6,211 ) (4,196 ) Net loss (5,979,664 ) (6,057,254 ) (6,067,546 ) (6,044,162 ) Net loss per share, basic and diluted (1) (0.38 ) (0.31 ) (0.31 ) (0.30 ) 2014 First Quarter Second Quarter Third Quarter Fourth Quarter Total operating expenses $ 5,245,845 $ 5,304,756 $ 6,416,237 $ 5,321,344 Total other income (expense) 2,489 1,732 (20,923 ) (15,007 ) Net loss (5,243,356 ) (5,303,024 ) (6,437,160 ) (5,336,351 ) Net loss per share, basic and diluted (1) (0.34 ) (0.34 ) (0.42 ) (0.34 ) |
Organization and Basis of Pre28
Organization and Basis of Presentation - Additional Information (Detail) | 1 Months Ended | 12 Months Ended | |
Jul. 31, 2013USD ($)$ / sharesshares | Dec. 31, 2015USD ($) | Dec. 31, 2014USD ($) | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |||
Date of incorporation | Jul. 13, 2005 | ||
Accumulated deficit | $ (120,899,011) | $ (96,750,385) | |
Cash, cash equivalents and marketable securities | 36,500,000 | ||
Working capital | $ 34,500,000 | ||
Reverse stock split of outstanding common stock | 1-for-8.25 | ||
Reverse stock split of outstanding common stock ratio | 0.12 | ||
Common stock issued in initial public offering (IPO) | shares | 6,000,000 | ||
Initial public offering of common stock, price per share | $ / shares | $ 11 | ||
Net proceeds from initial public offering (IPO) | $ 58,600,000 |
Summary of Significant Accoun29
Summary of Significant Accounting Policies - Additional Information (Detail) | 12 Months Ended | ||
Dec. 31, 2015USD ($)Segment | Dec. 31, 2014USD ($) | Dec. 31, 2013USD ($) | |
Property, Plant and Equipment [Line Items] | |||
Realized gains and losses on investments | $ 0 | $ 0 | $ 0 |
Other-than-temporary declines in value of marketable securities | 0 | 0 | 0 |
Impairment losses not recognized | 0 | ||
Unrecognized tax benefits | $ 981,380 | 571,194 | 457,106 |
Risk-free interest rate basis | The risk-free interest rate is based on the average yield of five- and seven-year U.S. Treasury Bills as of the valuation date. | ||
Stock-based compensation | $ 3,315,943 | $ 2,330,660 | $ 257,451 |
Unrecognized compensation expense | $ 6,300,000 | ||
Weighted-average vesting term | 2 years 4 months 24 days | ||
Number of operating segment | Segment | 1 | ||
Minimum [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Estimated useful lives of the assets | 3 years | ||
Maximum [Member] | |||
Property, Plant and Equipment [Line Items] | |||
Estimated useful lives of the assets | 5 years |
Summary of Significant Accoun30
Summary of Significant Accounting Policies - Schedule of Black-Scholes Option Pricing Model Assumptions (Detail) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Risk-free interest rate - Minimum | 1.54% | 1.69% | 0.95% |
Risk-free interest rate - Maximum | 1.94% | 2.10% | 1.81% |
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Expected volatility - Minimum | 72.00% | 78.00% | 69.00% |
Expected volatility - Maximum | 89.00% | 105.00% | 79.00% |
Minimum [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected term (in years) | 5 years 6 months | 5 years 6 months | 6 years |
Maximum [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected term (in years) | 6 years 1 month 6 days | 6 years 1 month 6 days | 6 years 1 month 6 days |
Summary of Significant Accoun31
Summary of Significant Accounting Policies - Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Detail) - shares | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 2,651,902 | 2,146,133 | 1,173,631 |
ESPP shares pending issuance [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 5,103 | 2,175 | |
Warrants to purchase common stock [Member] | Common Stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 149,704 | 149,704 | 149,704 |
Common stock options issued and outstanding [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 2,464,849 | 1,859,034 | 790,590 |
Common stock subject to repurchase [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 32,246 | 135,220 | 233,337 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - USD ($) | Dec. 31, 2015 | Dec. 31, 2014 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | $ 34,556,480 | $ 35,657,442 |
Money market funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 10,221,563 | 6,998,111 |
Corporate debt securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 24,334,917 | 28,589,331 |
Municipal bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 70,000 | |
Level 1 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 10,221,563 | 6,998,111 |
Level 1 [Member] | Money market funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 10,221,563 | 6,998,111 |
Level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 24,334,917 | 28,659,331 |
Level 2 [Member] | Corporate debt securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | $ 24,334,917 | 28,589,331 |
Level 2 [Member] | Municipal bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | $ 70,000 |
Fair Value Measurements - Fair
Fair Value Measurements - Fair Value Measurements of Using Significant Unobservable Level 3 Inputs (Detail) | 12 Months Ended |
Dec. 31, 2013USD ($) | |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Changes in fair value reflected as other financing expense | $ 3,457,184 |
Convertible promissory notes [Member] | |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Beginning balance | 0 |
Issuance of securities | 970,000 |
Accretion of debt discount to interest expense | 31,439 |
Conversion to equity at IPO | (1,001,439) |
Ending balance | 0 |
Preferred stock warrant liability [Member] | |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | |
Beginning balance | 160,345 |
Issuance of securities | 625,679 |
Changes in fair value reflected as other financing expense | 3,457,184 |
Conversion to equity at IPO | (4,243,208) |
Ending balance | $ 0 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Detail) - Convertible promissory notes [Member] | 12 Months Ended |
Dec. 31, 2015USD ($) | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |
Discount rate on fair value | 15.00% |
Initial fair value of notes | $ 970,000 |
Marketable Securities - Summary
Marketable Securities - Summary of Marketable Securities (Detail) - USD ($) | Dec. 31, 2015 | Dec. 31, 2014 |
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 22,635,926 | $ 27,172,569 |
Unrealized Gains | 6,770 | 1,137 |
Unrealized Losses | (10,677) | (14,434) |
Estimated Fair Value | 22,632,019 | 27,159,272 |
Corporate debt securities [Member] | 1 or less years of maturity [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 22,635,926 | 25,795,008 |
Unrealized Gains | 6,770 | 1,137 |
Unrealized Losses | (10,677) | (9,223) |
Estimated Fair Value | $ 22,632,019 | 25,786,922 |
Corporate debt securities [Member] | 1 - 2 years of maturity [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 1,307,561 | |
Unrealized Losses | (5,211) | |
Estimated Fair Value | 1,302,350 | |
Municipal bonds [Member] | 1 or less years of maturity [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 70,000 | |
Estimated Fair Value | $ 70,000 |
Property and Equipment - Schedu
Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) | Dec. 31, 2015 | Dec. 31, 2014 |
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 639,766 | $ 464,242 |
Less accumulated depreciation and amortization | (295,032) | (227,176) |
Total | 344,734 | 237,066 |
Furniture and fixtures [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 326,788 | 239,788 |
Computer equipment and office equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 170,946 | 162,921 |
Leasehold improvements [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 142,032 | $ 61,533 |
Property and Equipment - Additi
Property and Equipment - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Property Plant And Equipment [Abstract] | |||
Depreciation | $ 67,856 | $ 38,258 | $ 10,446 |
Notes Payable - Additional Info
Notes Payable - Additional Information (Detail) - USD ($) | 1 Months Ended | 12 Months Ended | |||||
Jul. 31, 2013 | Dec. 31, 2015 | Dec. 31, 2013 | Dec. 31, 2014 | May. 31, 2013 | May. 30, 2013 | Jul. 31, 2010 | |
Debt Instrument [Line Items] | |||||||
Note payable | $ 1,000,000 | $ 1,000,000 | |||||
Warrants exercisable, outstanding | 149,704 | 149,704 | 149,704 | ||||
Deemed distribution from promissory note and warrant issuance | $ 474,561 | ||||||
2013 Warrants [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Conversion of notes plus accrued interest into shares of common stock | 91,948 | ||||||
2013 Warrants [Member] | Common Stock [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Exercise price of warrant per share | $ 7.43 | ||||||
Warrants exercisable, outstanding | 13,468 | ||||||
2013 Warrants [Member] | Series B Preferred Stock [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Warrant exercisable to purchase shares | 1,124,026 | ||||||
Oxford Finance LLC and Silicon Valley Bank [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Line of credit facility, maximum borrowing capacity | $ 15,000,000 | ||||||
Promissory note [Member] | Pfizer Inc. [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Note payable | $ 1,000,000 | ||||||
Debt instrument, interest rate | 7.00% | ||||||
Debt instrument, maturity date | Jul. 29, 2020 | ||||||
Convertible promissory notes [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Debt instrument, interest rate | 6.00% | ||||||
Convertible promissory note | $ 1,000,000 | ||||||
Maturity and repayment terms | The 2013 Notes accrued interest at a rate of 6% per annum and were due and payable on the earlier of (1) any date after November 30, 2013 upon which holders of 75% of the outstanding principal amount of all such 2013 Notes demand repayment, or (2) the occurrence of a change of control of the Company, subject in each case to their earlier conversion in the event the Company completed a qualified initial public offering or private placement of debt and/or equity. | ||||||
Discount rate on fair value | 15.00% | ||||||
Initial fair value of notes | $ 970,000 | ||||||
Convertible promissory notes [Member] | 2013 Warrants [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Warrant expiration date | May 30, 2018 | ||||||
Initial value of warrants | $ 506,000 | ||||||
Deemed distribution from promissory note and warrant issuance | $ 474,561 | ||||||
Convertible promissory notes [Member] | 2013 Warrants [Member] | Common Stock [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Exercise price of warrant per share | $ 7.43 | $ 7.43 | |||||
Convertible promissory notes [Member] | 2013 Warrants [Member] | Common Stock [Member] | Post IPO [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Warrants exercisable, outstanding | 136,236 | ||||||
Convertible promissory notes [Member] | 2013 Warrants [Member] | Series B Preferred Stock [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Exercise price of warrant per share | $ 0.90 | ||||||
Term loan one [Member] | Series B convertible preferred stock [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Exercise price of warrant per share | $ 0.90 | ||||||
Warrant expiration date | Jul. 3, 2023 | ||||||
Credit facility termination date | Sep. 25, 2013 | ||||||
Warrant issued | 111,112 | ||||||
Carrying value of warrant | $ 119,679 | ||||||
Term loan one [Member] | Oxford Finance LLC and Silicon Valley Bank [Member] | |||||||
Debt Instrument [Line Items] | |||||||
Line of credit facility, maximum borrowing capacity | $ 1,000,000 |
Convertible Preferred Stock a39
Convertible Preferred Stock and Stockholders' Equity (Deficit) - Additional Information (Detail) | May. 30, 2013USD ($)$ / sharesshares | Apr. 30, 2015USD ($)$ / sharesshares | Aug. 31, 2014USD ($) | Jul. 31, 2013USD ($)$ / sharesshares | Dec. 31, 2015USD ($)$ / sharesshares | Dec. 31, 2014USD ($)$ / sharesshares | Dec. 31, 2013USD ($)$ / sharesshares | May. 31, 2013$ / shares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Reverse stock split of outstanding common stock | 1-for-8.25 | |||||||
Reverse stock split of outstanding common stock ratio | 0.12 | |||||||
Common stock, shares issued under sales agreement | 6,000,000 | |||||||
Initial public offering of common stock, price per share | $ / shares | $ 11 | |||||||
Net proceeds from initial public offering | $ | $ 58,600,000 | |||||||
Common stock, value of shares issued under sales agreement | $ | $ 1,984 | $ 1,556 | ||||||
Net proceeds from the issuance of common stock | $ | $ 21,400,000 | $ 22,305,226 | $ 58,608,454 | |||||
Preferred stock, shares outstanding | 0 | 0 | ||||||
Shares on a post-reverse stock split basis | 188,808 | |||||||
Adjustment to additional paid in capital, carrying amount | $ | $ 11,491,043 | 11,491,043 | ||||||
Conversion of shares | 7,676,914 | |||||||
Fair value of warrants | $ | $ 3,457,184 | |||||||
Warrants exercisable, outstanding | 149,704 | 149,704 | 149,704 | |||||
Remaining options available for future grant | 593,531 | 403,859 | ||||||
Weighted-average fair value of options granted | $ / shares | $ 4.31 | $ 6.77 | $ 6.31 | |||||
Intrinsic value of options outstanding | $ | $ 100,000 | $ 500,000 | $ 1,100,000 | |||||
Number of shares subject to repurchase | 32,246 | 135,220 | ||||||
Total related liability for early exercise of option | $ | $ 2,902 | $ 27,306 | ||||||
Intrinsic value of options outstanding | $ | 800,000 | |||||||
Intrinsic value of options vested or expected to vest | $ | 800,000 | |||||||
Intrinsic value of options exercisable | $ | $ 800,000 | |||||||
Common stock, shares issued | 19,877,857 | 15,695,834 | ||||||
Accounts payable and accrued expenses | $ | $ 2,545,894 | $ 3,003,612 | ||||||
2006 Plan [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Common stock reserved for issuance to employees, nonemployee directors and consultants | 1,030,303 | |||||||
2013 Plan [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Common stock reserved for issuance to employees, nonemployee directors and consultants | 1,000,000 | |||||||
Stock option plans, maximum term of plan | 10 years | |||||||
Stock option plans, remaining vesting period | 3 years | |||||||
Percentage of outstanding shares of common stock | 5.00% | |||||||
Remaining options available for future grant | 593,531 | |||||||
2013 Plan [Member] | Tranche right [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Stock option plans, percentage of options vested | 25.00% | |||||||
Series A Warrants [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Convertible preferred stock warrants | 280,675 | |||||||
Convertible preferred stock [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Preferred stock, shares outstanding | 15,576,789 | 63,334,653 | ||||||
Series A Preferred Stock [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Warrant issued | 2,333,320 | |||||||
Follow on Offering [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Common stock, shares issued under sales agreement | 4,025,000 | |||||||
Initial public offering of common stock, price per share | $ / shares | $ 5.75 | |||||||
IPO [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Legal and accounting costs | $ | $ 100,000 | |||||||
Employee Stock Purchase Plan [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Lower fair market value of purchase price share | 85.00% | |||||||
Common stock, shares issued | 17,914 | 0 | ||||||
Accounts payable and accrued expenses | $ | $ 15,789 | $ 13,167 | ||||||
Maximum [Member] | Employee Stock Purchase Plan [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Employee stock purchase plan, employees contribution | 20.00% | |||||||
Sales Agreement with MLV & Co LLC [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Common stock, shares issued under sales agreement | 149,805 | |||||||
Net proceeds from the issuance of common stock | $ | $ 600,000 | |||||||
Legal and accounting costs | $ | $ 200,000 | |||||||
Sales Agreement with MLV & Co LLC [Member] | Maximum [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Common stock, value of shares issued under sales agreement | $ | $ 50,000,000 | |||||||
Percentage of commission of gross sales price per share | 3.00% | |||||||
Sales Agreement with MLV & Co LLC [Member] | Weighted Average [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Common stock, price per share | $ / shares | $ 6.05 | |||||||
Common Stock [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Reverse stock split of outstanding common stock | 1-for-8.25 | |||||||
Reverse stock split of outstanding common stock ratio | 0.12 | |||||||
Common stock, shares issued under sales agreement | 4,174,805 | 6,000,000 | ||||||
Common stock due to conversion, shares | 1,557,678 | 91,948 | ||||||
Common Stock [Member] | 2013 Warrants [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Warrants exercisable, outstanding | 13,468 | |||||||
Exercise price of warrant per share | $ / shares | $ 7.43 | |||||||
Common Stock [Member] | 2013 Warrants [Member] | Convertible promissory notes [Member] | ||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||
Exercise price of warrant per share | $ / shares | $ 7.43 | $ 7.43 |
Convertible Preferred Stock a40
Convertible Preferred Stock and Stockholders' Equity (Deficit) - Summary of Stock Option Activity (Detail) - $ / shares | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |||
Total Options, Beginning balance | 1,859,034 | 790,590 | 690,223 |
Total Options, Granted | 822,250 | 1,212,000 | 316,935 |
Total Options, Exercised | (21,029) | (81,056) | (174,447) |
Total Options, Cancelled | (195,406) | (62,500) | (42,121) |
Total Options, Ending balance | 2,464,849 | 1,859,034 | 790,590 |
Total Options, Vested or expected to vest | 2,288,775 | ||
Total Options, Exercisable | 1,071,325 | ||
Weighted-Average Exercise Price, Beginning balance | $ 6.84 | $ 4.01 | $ 0.80 |
Weighted-Average Exercise Price, Granted | 6.03 | 8.41 | 9.44 |
Weighted-Average Exercise Price, Exercised | 1.04 | 1.10 | 0.24 |
Weighted-Average Exercise Price, Cancelled | 7.79 | 9.09 | 7.86 |
Weighted-Average Exercise Price, Ending balance | 6.54 | $ 6.84 | $ 4.01 |
Weighted-Average Exercise Price, Vested | 6.58 | ||
Weighted-Average Exercise Price, Vested, Exercisable | $ 5.75 | ||
Weighted-Average Remaining Contractual Term Outstanding | 7 years 10 months 13 days | ||
Weighted-Average Remaining Contractual Term Vested or expected to vest | 7 years 9 months 7 days | ||
Weighted-Average Remaining Contractual Term Exercisable | 6 years 7 months 28 days |
Convertible Preferred Stock a41
Convertible Preferred Stock and Stockholders' Equity (Deficit) - Summary of Common Stock Reserved for Future Issuance (Detail) - shares | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 |
Equity [Abstract] | |||
Warrants exercisable, outstanding | 149,704 | 149,704 | 149,704 |
Common stock options issued and outstanding | 2,464,849 | 1,859,034 | |
Common stock authorized for future option grants | 593,531 | 403,859 | |
Common stock authorized for the ESPP | 432,086 | 300,000 | |
Total | 3,640,170 | 2,712,597 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Operating Loss Carryforwards [Line Items] | |||
Cumulative change in ownership percentage | 50.00% | ||
Period for cumulative change in ownership percentage | 3 years | ||
Research credit carryforwards expiration year | 2,026 | ||
Deferred tax asset, change in valuation allowance amount | $ 10.3 | $ 8.9 | |
Minimum percentage of likelihood for uncertain tax position to be recognized | 50.00% | ||
Recognized interest or penalties on income tax | $ 0 | $ 0 | $ 0 |
Federal [Member] | |||
Operating Loss Carryforwards [Line Items] | |||
Operating loss carryforwards | 83.3 | ||
Research credit carryforwards | $ 3.6 | ||
Operating loss carryforwards expiration year | 2,025 | ||
State [Member] | |||
Operating Loss Carryforwards [Line Items] | |||
Operating loss carryforwards | $ 83.5 | ||
Research credit carryforwards | $ 1.3 | ||
Operating loss carryforwards expiration year | 2,016 |
Income Taxes - Components of Co
Income Taxes - Components of Company's Deferred Tax Assets (Detail) - USD ($) | Dec. 31, 2015 | Dec. 31, 2014 |
Deferred tax assets | ||
Net operating loss carryovers | $ 33,007,000 | $ 25,258,000 |
Research and development tax credits | 3,585,000 | 2,017,000 |
Intangibles | 922,000 | 1,090,000 |
Stock options | 1,614,000 | 744,000 |
Compensation | 553,000 | 423,000 |
Other | 212,000 | 100,000 |
Total gross deferred tax assets | 39,893,000 | 29,632,000 |
Less valuation allowance | (39,893,000) | (29,632,000) |
Net deferred tax assets | $ 0 | $ 0 |
Income Taxes - Reconciliation o
Income Taxes - Reconciliation of Statutory Tax Rates and Effective Tax Rates (Detail) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Income Tax Disclosure [Abstract] | |||
Statutory rate | 34.00% | 34.00% | 34.00% |
State tax, net of federal benefit | 5.83% | 5.83% | 5.83% |
Valuation allowance | (42.48%) | (39.85%) | (7.75%) |
Gain on distribution of subsidiary | (0.00%) | (0.00%) | (24.49%) |
Nondeductible interest | (0.00%) | (0.00%) | (9.08%) |
Other | 2.65% | 0.02% | 1.49% |
Effective tax rate | 0.00% | 0.00% | 0.00% |
Income Taxes - Unrecognized Tax
Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Income Tax Disclosure [Abstract] | |||
Balance at beginning of year | $ 571,194 | $ 457,106 | |
Additions based on tax positions related to the current year | 337,862 | 141,866 | $ 97,412 |
Additions for tax positions of prior years | 72,324 | 359,694 | |
Reductions for tax positions of prior years | (27,778) | ||
Settlement of tax audits | 0 | 0 | |
Reductions due to lapsed statute of limitations | 0 | 0 | |
Balance at end of year | $ 981,380 | $ 571,194 | $ 457,106 |
Employee Benefits - Additional
Employee Benefits - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Postemployment Benefits [Abstract] | |||
Defined contribution plan, Employees voluntary contributions, Amount | $ 164,989 | $ 130,769 | $ 92,562 |
Eligibility criteria for employees to participate in the plan | Employees are eligible to participate in the plan beginning on the first day of employment. |
Commitments - Additional Inform
Commitments - Additional Information (Detail) - USD ($) | 1 Months Ended | 12 Months Ended | |||
May. 31, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | Jul. 31, 2010 | |
Operating Leased Assets [Line Items] | |||||
Rent expense | $ 339,053 | $ 243,832 | $ 167,998 | ||
Amount payable upon the achievement of specified regulatory milestone | $ 18,000,000 | ||||
Operating lease term July 2014 through December 2019 [Member] | |||||
Operating Leased Assets [Line Items] | |||||
Lease renewal term | 5 years | ||||
Future minimum payments for noncancelable operating lease | $ 2,000,000 | ||||
Operating lease term September 2015 through September 2020 [Member] | |||||
Operating Leased Assets [Line Items] | |||||
Percentage of base rent escalator | 3.00% | ||||
Rent expense | $ 32,784 | ||||
Lease agreement rent expense for future period | $ 39,268 |
Spin-off of Idun Pharmaceutic48
Spin-off of Idun Pharmaceuticals, Inc. - Additional Information (Detail) - USD ($) | 1 Months Ended | 12 Months Ended |
Jan. 31, 2013 | Dec. 31, 2013 | |
Restructuring Cost and Reserve [Line Items] | ||
Change in equity as a result of spin-off | $ (500,000) | |
Idun Pharmaceuticals, Inc. [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Change in equity as a result of spin-off | $ 500,000 | |
Idun Pharmaceuticals, Inc. [Member] | Spin-off [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Payments for restructuring | $ 500,000 |
Quarterly Financial Data - Summ
Quarterly Financial Data - Summary of Quarterly Financial Data (Detail) - USD ($) | 3 Months Ended | 12 Months Ended | |||||||||||||||||
Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |||||||||
Quarterly Financial Information Disclosure [Abstract] | |||||||||||||||||||
Total operating expenses | $ 6,039,966 | $ 6,061,335 | $ 6,064,479 | $ 5,964,922 | $ 5,321,344 | $ 6,416,237 | $ 5,304,756 | $ 5,245,845 | $ 24,130,702 | $ 22,288,182 | $ 11,598,246 | ||||||||
Total other (expense) income | (4,196) | (6,211) | 7,225 | (14,742) | (15,007) | (20,923) | 1,732 | 2,489 | (17,924) | (31,709) | (4,018,246) | ||||||||
Net loss | $ (6,044,162) | $ (6,067,546) | $ (6,057,254) | $ (5,979,664) | $ (5,336,351) | $ (6,437,160) | $ (5,303,024) | $ (5,243,356) | $ (24,148,626) | $ (22,319,891) | $ (15,616,492) | ||||||||
Net loss per share, basic and diluted | $ (0.30) | [1] | $ (0.31) | [1] | $ (0.31) | [1] | $ (0.38) | [1] | $ (0.34) | [1] | $ (0.42) | [1] | $ (0.34) | [1] | $ (0.34) | [1] | $ (1.30) | $ (1.44) | $ (0.63) |
[1] | Net loss per share is computed independently for each quarter and the full year based upon respective shares outstanding; therefore, the sum of the quarterly net loss per share amounts may not equal the annual amounts reported. |
Subsequent Events - Additional
Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions | 1 Months Ended | 2 Months Ended |
Jul. 31, 2013 | Mar. 11, 2016 | |
Subsequent Event [Line Items] | ||
Common stock, shares issued under sales agreement | 6,000,000 | |
Subsequent Events [Member] | ||
Subsequent Event [Line Items] | ||
Common stock, shares issued under sales agreement | 930,101 | |
Agreement at an average price per share | $ 2.78 | |
Net proceeds after deducting offering related transaction costs and commissions. | $ 2.6 |