Document and Entity Information
Document and Entity Information - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2017 | Mar. 01, 2018 | Jun. 30, 2017 | |
Document And Entity Information [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2017 | ||
Document Fiscal Year Focus | 2,017 | ||
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 | 30,059,999 | ||
Entity Public Float | $ 160.8 |
Balance Sheets
Balance Sheets - USD ($) | Dec. 31, 2017 | Dec. 31, 2016 |
Current assets: | ||
Cash and cash equivalents | $ 16,078,836 | $ 58,083,409 |
Marketable securities | 58,774,411 | 18,931,715 |
Collaboration receivables | 3,366,585 | 2,500,000 |
Prepaid and other current assets | 1,004,198 | 937,436 |
Total current assets | 79,224,030 | 80,452,560 |
Property and equipment, net | 178,649 | 261,446 |
Other assets | 2,538,211 | 1,609,834 |
Total assets | 81,940,890 | 82,323,840 |
Current liabilities: | ||
Accounts payable and accrued expenses | 11,961,983 | 5,311,093 |
Accrued compensation | 2,008,288 | 2,351,703 |
Current portion of deferred revenue | 14,172,076 | 30,897,192 |
Note payable | 0 | 1,000,000 |
Total current liabilities | 28,142,347 | 39,559,988 |
Deferred revenue, less current portion | 12,518,667 | 20,803,762 |
Convertible note payable | 13,157,534 | 0 |
Deferred rent | 126,030 | 171,544 |
Stockholders’ equity: | ||
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding | 0 | 0 |
Common stock, $0.0001 par value; 200,000,000 shares authorized; 30,034,757 shares issued and outstanding at December 31, 2017; 26,118,722 shares issued and outstanding at December 31, 2016 | 3,003 | 2,612 |
Additional paid-in capital | 196,077,250 | 172,424,531 |
Accumulated other comprehensive loss | (77,076) | (6,145) |
Accumulated deficit | (168,006,865) | (150,632,452) |
Total stockholders’ equity | 27,996,312 | 21,788,546 |
Total liabilities and stockholders’ equity | $ 81,940,890 | $ 82,323,840 |
Balance Sheets (Parenthetical)
Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2017 | Dec. 31, 2016 |
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 | 30,034,757 | 26,118,722 |
Common stock, shares outstanding | 30,034,757 | 26,118,722 |
Statements of Operations and Co
Statements of Operations and Comprehensive Loss - USD ($) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Revenues: | |||
Collaboration revenue | $ 35,376,796 | $ 799,046 | $ 0 |
Total revenues | 35,376,796 | 799,046 | 0 |
Operating expenses: | |||
Research and development | 43,220,446 | 20,293,632 | 16,297,617 |
General and administrative | 9,706,834 | 10,337,182 | 7,833,085 |
Total operating expenses | 52,927,280 | 30,630,814 | 24,130,702 |
Loss from operations | (17,550,484) | (29,831,768) | (24,130,702) |
Other income (expense): | |||
Interest income | 892,178 | 138,413 | 67,885 |
Interest expense | (662,395) | (70,000) | (70,000) |
Other (expense) income | (75,712) | 29,914 | (15,809) |
Total other income (expense) | 154,071 | 98,327 | (17,924) |
Net loss | (17,396,413) | (29,733,441) | (24,148,626) |
Other comprehensive income (loss): | |||
Net unrealized (losses) gains on marketable securities | (70,931) | (2,238) | 9,390 |
Comprehensive loss | $ (17,467,344) | $ (29,735,679) | $ (24,139,236) |
Net loss per share, basic and diluted | $ (0.61) | $ (1.31) | $ (1.30) |
Weighted average shares outstanding used in computing net loss per share, basic and diluted | 28,586,625 | 22,649,911 | 18,617,537 |
Statements of Stockholders' Equ
Statements of Stockholders' Equity - USD ($) | Total | Common Stock [Member] | Additional Paid-in Capital [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Accumulated Deficit [Member] |
Beginning balance at Dec. 31, 2014 | $ 33,213,949 | $ 1,556 | $ 129,976,075 | $ (13,297) | $ (96,750,385) |
Beginning 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 | ||||
Vesting of early exercise of employee stock options | 2,902 | $ 3 | 2,899 | ||
Vesting of early exercise of employee stock options, shares | 29,707 | ||||
Issuance of common stock upon exercise of stock options | $ 55,929 | $ 6 | 55,923 | ||
Issuance of common stock upon exercise of stock options, shares | 60,807 | 60,807 | |||
Issuance of common stock for employee stock purchase plan | $ 49,679 | $ 3 | 49,676 | ||
Issuance of common stock for employee stock purchase plan, shares | 26,876 | ||||
Share-based compensation | 3,353,456 | 3,353,456 | |||
Issuance of common stock, net of offering costs | 13,521,913 | $ 616 | 13,521,297 | ||
Issuance of common stock, net of offering costs, shares | 6,155,721 | ||||
Net loss | (29,733,441) | (29,733,441) | |||
Unrealized gain (loss) on marketable securities | (2,238) | (2,238) | |||
Ending balance at Dec. 31, 2016 | 21,788,546 | $ 2,612 | 172,424,531 | (6,145) | (150,632,452) |
Ending balance, shares at Dec. 31, 2016 | 26,118,722 | ||||
Issuance of common stock upon exercise of stock options | $ 103,821 | $ 8 | 103,813 | ||
Issuance of common stock upon exercise of stock options, shares | 78,568 | 78,568 | |||
Issuance of common stock for employee stock purchase plan | $ 65,650 | $ 2 | 65,648 | ||
Issuance of common stock for employee stock purchase plan, shares | 24,303 | ||||
Share-based compensation | 4,098,392 | 4,076,392 | 22,000 | ||
Issuance of common stock, net of offering costs | 30,609,789 | $ 598 | 30,609,191 | ||
Issuance of common stock, net of offering costs, shares | 5,980,000 | ||||
Repurchase of common stock | (11,202,542) | $ (217) | (11,202,325) | ||
Repurchase of common stock, shares | (2,166,836) | ||||
Net loss | (17,396,413) | (17,396,413) | |||
Unrealized gain (loss) on marketable securities | (70,931) | (70,931) | |||
Ending balance at Dec. 31, 2017 | $ 27,996,312 | $ 3,003 | $ 196,077,250 | $ (77,076) | $ (168,006,865) |
Ending balance, shares at Dec. 31, 2017 | 30,034,757 |
Statements of Cash Flows
Statements of Cash Flows - USD ($) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Operating activities | |||
Net loss | $ (17,396,413) | $ (29,733,441) | $ (24,148,626) |
Adjustments to reconcile net loss to net cash (used in) provided by operating activities: | |||
Depreciation | 108,303 | 105,841 | 67,856 |
Stock-based compensation expense | 4,098,392 | 3,353,456 | 3,315,943 |
Amortization of premiums and discounts on marketable securities, net | (67,883) | 5,716 | 328,479 |
Accrued interest included in convertible note payable | 657,534 | 0 | 0 |
Changes in operating assets and liabilities: | |||
Collaboration receivables | (866,585) | (2,500,000) | 0 |
Prepaid and other current assets | (123,028) | 934,991 | (1,185,213) |
Other assets | (872,111) | (624,101) | (798,754) |
Accounts payable and accrued expenses | 6,638,056 | 2,856,020 | (581,218) |
Accrued compensation | (343,415) | 917,801 | 289,587 |
Deferred revenue | (25,010,211) | 51,700,954 | 0 |
Deferred rent | (32,680) | (20,236) | 165,761 |
Net cash (used in) provided by operating activities | (33,210,041) | 26,997,001 | (22,546,185) |
Investing activities | |||
Maturities of marketable securities | 81,877,000 | 44,597,000 | 62,574,000 |
Purchase of marketable securities | (121,722,744) | (40,904,650) | (58,365,836) |
Capital expenditures | (25,506) | (109,553) | (88,524) |
Net cash (used in) provided by investing activities | (39,871,250) | 3,582,797 | 4,119,640 |
Financing activities | |||
Proceeds from issuance of convertible note payable, net | 12,500,000 | 0 | 0 |
Principal payment on promissory note | (1,000,000) | 0 | 0 |
Proceeds from issuance of common stock, net | 30,609,789 | 13,521,913 | 22,305,226 |
Repurchase of common stock | (11,202,542) | 0 | 0 |
Proceeds from stock issuances related to exercise of stock options and employee stock purchase plan | 169,471 | 105,608 | 84,735 |
Net cash provided by financing activities | 31,076,718 | 13,627,521 | 22,389,961 |
Net (decrease) increase in cash and cash equivalents | (42,004,573) | 44,207,319 | 3,963,416 |
Cash and cash equivalents at beginning of period | 58,083,409 | 13,876,090 | 9,912,674 |
Cash and cash equivalents at end of period | 16,078,836 | 58,083,409 | 13,876,090 |
Supplemental disclosure of cash flow information: | |||
Cash paid for interest | 4,861 | 70,000 | 70,000 |
Supplemental schedule of noncash investing and financing activities: | |||
Purchases of property and equipment included in accounts payable | $ 0 | $ 0 | $ 87,000 |
Organization and Basis of Prese
Organization and Basis of Presentation | 12 Months Ended |
Dec. 31, 2017 | |
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, 2017, the Company has devoted substantially all of its efforts to product development and has not realized product sales 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, 2017, had an accumulated deficit of $168.0 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, 2017, the Company had cash, cash equivalents and marketable securities of $74.9 million and working capital of $51.1 million. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2017 | |
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. 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, 2017, 2016 and 2015. 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 period 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, 2017, 2016 and 2015, 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, 2017. Revenue Recognition The Company recognizes revenue when each of the following four criteria is met: (i) persuasive evidence of an arrangement exists; (ii) products are delivered or as services are rendered; (iii) the sales price is fixed or determinable; and (iv) collectability is reasonably assured. The Company recognizes revenue under its Option, Collaboration and License Agreement (the Collaboration Agreement) with Novartis Pharma AG (Novartis) based on the relevant accounting literature. Under this guidance, multiple elements or deliverables may include (i) grants of licenses, or options to obtain licenses, to intellectual property, (ii) research and development services, (iii) participation on joint research and/or joint development committees, and/or (iv) manufacturing or supply services. The payments entities may receive under these arrangements typically include one or more of the following: non-refundable, upfront license fees; option exercise fees; funding of research and/or development efforts; amounts due upon the achievement of specified objectives; and/or royalties on future product sales. Multiple-element arrangements require the separability of deliverables included in an arrangement into different units of accounting and the allocation of arrangement consideration to the units of accounting. The evaluation of multiple-element arrangements requires management to make judgments about (i) the identification of deliverables, (ii) whether such deliverables are separable from the other aspects of the contractual relationship, (iii) the estimated selling price of each deliverable, and (iv) the expected period of performance for each deliverable. To determine the units of accounting under a multiple-element arrangement, management evaluates certain separation criteria, including whether the deliverables have stand-alone value, based on the relevant facts and circumstances for each arrangement. Management then estimates the selling price for each unit of accounting and allocates the arrangement consideration to each unit using the relative selling price method. The allocated consideration for each unit of accounting is recognized based on the method most appropriate for that unit of account and in accordance with the revenue recognition criteria detailed above. If there are deliverables in an arrangement that are not separable from other aspects of the contractual relationship, they are treated as a combined unit of accounting, with the allocated revenue for the combined unit recognized in a manner consistent with the revenue recognition applicable to the final deliverable in the combined unit. Payments received prior to satisfying the relevant revenue recognition criteria are recorded as deferred revenue in the accompanying balance sheets and recognized as revenue when the related revenue recognition criteria are met. The Collaboration Agreement provides for non-refundable milestone payments. The Company recognizes revenue that is contingent upon the achievement of a substantive milestone in its entirety in the period in which the milestone is achieved. A milestone is considered substantive when the consideration payable to the Company for such milestone (i) is consistent with the Company’s performance necessary to achieve the milestone or the increase in value to the collaboration resulting from the Company’s performance, (ii) relates solely to the Company’s past performance and (iii) is reasonable relative to all of the other deliverables and payments within the arrangement. In making this assessment, the Company considers all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. The Company periodically reviewed the estimated performance periods under the Collaboration Agreement, which provides for non-refundable upfront payments and fees. The Company adjusted the periods over which revenue was recognized when appropriate to reflect changes in assumptions relating to the estimated performance periods. In the first quarter of 2018, the Company will adopt new accounting guidance that will change future patterns of revenue recognition. The Company records revenues related to the reimbursement of costs incurred under the Collaboration Agreement where the Company acts as a principal, controls the research and development activities and bears credit risk. Under the Collaboration Agreement, the Company is reimbursed for associated out-of-pocket costs and for a certain amount of the Company’s full-time equivalent (FTE) costs based on an agreed-upon FTE rate. The gross amount of these pass-through reimbursed costs is reported as revenue in the accompanying statements of operations and comprehensive loss, while the actual expenses for which the Company is reimbursed are reflected as research and development costs. In the first quarter of 2018, the Company will adopt new accounting guidance that will change future patterns of revenue recognition. See Note 9 – Collaboration and License Agreements for further information. 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, 2017, 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, 2017, 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, and forfeitures are recognized as they occur. 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, 2017 2016 2015 Assumptions Risk-free interest rate 1.83% - 2.13% 1.15% - 1.55% 1.54% - 1.94% Expected dividend yield 0% 0% 0% Expected volatility 93% - 97% 84% 72% - 89% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 5.5 - 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. 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 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, 2017 2016 2015 Warrants to purchase common stock 149,704 149,704 149,704 Common stock options issued and outstanding 4,826,330 3,393,813 2,464,849 Shares issuable upon conversion of convertible note payable 2,965,078 — — Common stock subject to repurchase — — 32,246 ESPP shares pending issuance 4,842 2,659 5,103 Total 7,945,954 3,546,176 2,651,902 Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606). In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718). In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718). |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2017 | |
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, including cash equivalents and marketable securities, measured at fair value as of December 31, 2017 and 2016. Fair Value Measurements Using December 31, 2017 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 $ 12,217,656 $ 12,217,656 $ — $ — Corporate debt securities 61,774,107 — 61,774,107 — Total $ 73,991,763 $ 12,217,656 $ 61,774,107 $ — Fair Value Measurements Using December 31, 2016 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 $ 45,523,208 $ 45,523,208 $ — $ — Corporate debt securities 27,702,317 — 27,702,317 — Total $ 73,225,525 $ 45,523,208 $ 27,702,317 $ — 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. |
Marketable Securities
Marketable Securities | 12 Months Ended |
Dec. 31, 2017 | |
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, 2017 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 58,851,487 $ 312 $ (77,388 ) $ 58,774,411 Total $ 58,851,487 $ 312 $ (77,388 ) $ 58,774,411 As of December 31, 2016 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 18,937,860 $ 901 $ (7,046 ) $ 18,931,715 Total $ 18,937,860 $ 901 $ (7,046 ) $ 18,931,715 |
Property and Equipment
Property and Equipment | 12 Months Ended |
Dec. 31, 2017 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment | 5. Property and Equipment Property and equipment consist of the following: December 31, 2017 2016 Furniture and fixtures $ 333,670 $ 333,670 Computer equipment and office equipment 143,059 119,354 Leasehold improvements 152,217 152,217 628,946 605,241 Less accumulated depreciation and amortization (450,297 ) (343,795 ) Total $ 178,649 $ 261,446 Depreciation expense related to property and equipment was $108,303, $105,841 and $67,856 for the years ended December 31, 2017, 2016 and 2015, respectively. |
Notes Payable
Notes Payable | 12 Months Ended |
Dec. 31, 2017 | |
Debt Disclosure [Abstract] | |
Notes Payable | 6. Notes Payable In July 2010, the Company issued to Pfizer Inc. (Pfizer) a $1.0 million promissory note (the Pfizer Note). The Pfizer Note bore interest at a rate of 7% per annum and was scheduled to mature on July 29, 2020. Interest was payable on a quarterly basis. On January 24, 2017, the Company voluntarily prepaid the entire balance of the outstanding principal and accrued and unpaid interest of the Pfizer Note in the amount of $1,004,861. Prior to the prepayment of the Pfizer Note, the Company recorded the Pfizer Note on the balance sheet at face value. Based on borrowing rates available to the Company for loans with similar terms, the Company believed that the fair value of the Pfizer Note approximated its carrying value. The fair value measurement was categorized within Level 3 of the fair value hierarchy. On February 15, 2017, the Company issued a convertible promissory note (the Novartis Note) in the principal amount of $15.0 million, pursuant to the Investment Agreement entered into between the Company and Novartis on December 19, 2016 (the Investment Agreement). The Novartis Note bears interest on the unpaid principal balance at a rate of 6% per annum and has a scheduled maturity date of December 31, 2019. The Company may prepay or convert all or part of the Novartis Note into shares of the Company’s common stock, at its option, until December 31, 2019. Novartis has the option to convert all or part of the Novartis Note into shares of the Company’s common stock upon a change in control of the Company or termination of the Collaboration Agreement by Novartis pursuant to certain provisions. If converted, the principal and accrued interest under the Novartis Note will convert into the Company’s common stock at a conversion price equal to 120% of the 20-day trailing average closing price per share of the common stock immediately prior to the conversion date. In the event the aggregate number of shares of common stock issued upon the conversion would exceed the lesser of 19.0% of the Company’s outstanding shares on a fully-diluted basis (i) at the inception of the Investment Agreement or (ii) on the conversion date, then only the lesser amount shall convert into shares of common stock and Novartis shall be repaid in cash for any remaining principal and unpaid interest after such conversion. Upon the occurrence of certain events of default, the Novartis Note requires the Company to repay the principal balance of the Novartis Note and any unpaid accrued interest. The ability to borrow and repay the debt at a discount using shares of the Company’s common stock was deemed to be additional, foregone revenue attributable to the Collaboration Agreement, which the Company imputed and recorded as both a receivable from Novartis and a liability (deferred revenue) of $2.5 million at the inception of the Collaboration Agreement and the Investment Agreement. On February 15, 2017, the Company recorded the $15.0 million proceeds from the issuance of the Novartis Note as a convertible note payable in the amount of $12.5 million and a reduction of the outstanding receivable from Novartis of $2.5 million. The convertible note payable, along with the related accrued interest, totaled $13.2 million as of December 31, 2017. The Company elected to account for the Novartis Note under the fair value option. At December 31, 2017, the Company concluded that the fair value of the Novartis Note remained at $13.2 million due to its conversion features. The fair value measurement is categorized within Level 2 of the fair value hierarchy. |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2017 | |
Equity [Abstract] | |
Stockholders' Equity | 7. Stockholders’ Equity Common Stock 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 could 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 were 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. The Company agreed to pay a commission rate equal to up to 3% of the gross sales price per share sold. The Company 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. During the year ended December 31, 2016, the Company sold 6,155,721 shares of its common stock pursuant to the Sales Agreement at a weighted average price per share of $2.26 and received net proceeds of $13.5 million, after deducting offering-related transaction costs and commissions. The Company terminated the Sales Agreement in December 2016. 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. In May 2017, the Company completed a public offering of 5,980,000 shares of its common stock at a public offering price of $5.50 per share. The shares were registered pursuant to a registration statement on Form S-3 filed on August 14, 2014. The Company received net proceeds of $30.6 million, after deducting underwriting discounts and commissions and offering-related transaction costs. Immediately following the offering, the Company used $11.2 million of the net proceeds to repurchase and retire 2,166,836 shares of its common stock from funds affiliated with Advent Private Equity (collectively Advent) at a price of $5.17 per share , which is equal to the net proceeds per share that the Company received from the offering, before expenses, pursuant to a stock purchase agreement the Company entered into with Advent in May 2017. Warrants In 2013, the Company issued warrants exercisable for 1,124,026 shares of Series B preferred stock, at an exercise price of $0.90 per share, to certain existing investors in conjunction with a private placement (the 2013 Warrants) and warrants exercisable for 111,112 shares of Series B preferred stock, at an exercise price of $0.90 per share, to Oxford Finance LLC and Silicon Valley Bank in conjunction with the Company’s entry into a loan and security agreement (the Lender Warrants). Upon completion of the Company’s initial public offering (IPO), the 2013 Warrants and the Lender Warrants became exercisable for 136,236 and 13,468 shares of common stock, respectively, at an exercise price of $7.43 per share. The 2013 Warrants and the Lender Warrants will expire on May 30, 2018 and July 3, 2023, respectively. 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, 2017, a total of 614,106 options remain available for future grant under the 2013 Plan. On August 31, 2017, in connection with the appointment of its new Executive Vice President, Chief Operating Officer and Chief Financial Officer, the Company granted stock options to purchase 525,000 shares of the Company’s common stock outside of its stock option plans. The following table summarizes the Company’s stock option activity under all stock option plans for the three years ended December 31, 2017. Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Outstanding at December 31, 2014 1,859,034 $ 6.84 Granted 822,250 6.03 Exercised (21,029 ) 1.04 Forfeited/cancelled/expired (195,406 ) 7.79 Outstanding at December 31, 2015 2,464,849 6.54 Granted 1,132,500 1.96 Exercised (60,807 ) 0.92 Forfeited/cancelled/expired (142,729 ) 6.65 Outstanding at December 31, 2016 3,393,813 5.10 Granted 1,732,600 4.91 Exercised (78,568 ) 1.32 Forfeited/cancelled/expired (221,515 ) 6.09 Outstanding at December 31, 2017 4,826,330 $ 5.05 7.60 Vested or expected to vest at December 31, 2017 4,464,279 $ 5.06 7.50 Exercisable at December 31, 2017 2,540,481 $ 5.50 6.51 The weighted-average fair value of options granted for the years ended December 31, 2017, 2016 and 2015 were $3.79, $1.38 and $4.31, respectively. The total intrinsic value of stock options exercised during the years ended December 31, 2017, 2016 and 2015 were $0.3 million, $0.1 million and $0.1 million, respectively. At December 31, 2017, the intrinsic value of options outstanding, vested or expected to vest, and exercisable were $4.3 million, $4.2 million and $2.9 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 24,303, 26,876 and 17,914 shares of common stock under the ESPP for the years ended December 31, 2017, 2016 and 2015, respectively. The Company had an outstanding liability of $16,367, $4,521 and $15,789 at December 31, 2017, 2016 and 2015, 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. Stock-Based Compensation The Company recorded stock-based compensation of $4.1 million, $3.4 million and $3.3 million for the years ended December 31, 2017, 2016 and 2015, respectively. Unrecognized compensation expense at December 31, 2017 was $6.7 million, which is expected to be recognized over a weighted-average vesting term of 2.5 years. Common Stock Reserved for Future Issuance The following shares of common stock were reserved for future issuance at December 31, 2017 and 2016: December 31, 2017 2016 Warrants to purchase common stock 149,704 149,704 Common stock options issued and outstanding 4,826,330 3,393,813 Common stock authorized for future option grants 614,106 600,191 Common stock authorized for the ESPP 530,907 555,210 Shares issuable upon conversion of convertible note payable 2,965,078 — Total 9,086,125 4,698,918 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2017 | |
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. On December 22, 2017, President Trump signed into law the Tax Cuts and Jobs Act (the Tax Act), a tax reform bill which, among other items, reduces the current corporate federal income tax rate to 21% from 35%. The rate reduction is effective January 1, 2018. The Company concluded that the Tax Act will cause its deferred tax assets and liabilities to be revalued. Deferred income taxes result from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements that will result in taxable or deductible amounts in future years. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in years in which those temporary differences are expected to be recovered or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through income tax expense. Pursuant to the SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), a company may select between one of three scenarios to determine a reasonable estimate arising from the Tax Act. Those scenarios are (i) a final estimate which effectively closes the measurement window; (ii) a reasonable estimate leaving the measurement window open for future revisions; and (iii) no estimate as the law is still being analyzed. The Company was able to provide a reasonable estimate for the revaluation of deferred taxes for which the measurement window will remain open by recording a net tax provision of $16.2 million in the period ending December 31, 2017, which is offset by a full valuation allowance. This tax expense is primarily due to the corporate rate reduction. 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 performed an IRC Section 382/383 analysis regarding the limitation of net operating loss and research and development credit carryforwards during 2017, which determined an ownership change of more than 50% had occurred on October 27, 2006 as a result of the first issuance of the Company’s Series A Preferred Stock and another ownership change had occurred on July 30, 2013 as a result of the Company’s issuance of stock in connection with its IPO. As a result, the Company’s federal net operating losses were not forfeited with the exception of an immaterial amount. Significant components of the Company’s deferred tax assets at December 31, 2017 and 2016 are shown below: December 31, 2017 2016 Deferred tax assets Net operating loss carryovers $ 25,202,000 $ 41,103,000 Research and development tax credits 7,529,000 4,989,000 Intangibles 480,000 643,000 Stock options 1,840,000 2,071,000 Compensation 406,000 786,000 Other 5,667,000 486,000 Total gross deferred tax assets 41,124,000 50,078,000 Less valuation allowance (41,124,000 ) (50,078,000 ) Net deferred tax assets $ — $ — A reconciliation of the statutory tax rates and the effective tax rates for the years ended December 31, 2017, 2016 and 2015 is as follows: December 31, 2017 2016 2015 Statutory rate 34.00 % 34.00 % 34.00 % State tax, net of federal benefit 0.00 % 0.00 % 5.83 % Valuation allowance 51.50 % (34.26 %) (42.48 %) Federal tax rate change (93.30 %) 0.00 % 0.00 % General business credits 10.80 % 0.00 % 0.00 % Other (3.00 %) 0.26 % 2.65 % Effective tax rate — % — % — % At December 31, 2017, the Company had federal and state net operating loss carryforwards of $94.6 million and $76.4 million, respectively. The federal loss carryforwards begin to expire in 2028, unless previously utilized, and the state carryforwards began to expire in 2015. California net operating losses of $4.2 million expired in 2017. The Company also has federal and state research credit carryforwards of $7.7 million and $2.0 million, respectively. The federal research credit carryforwards will begin expiring in 2027, unless previously utilized. The state research credit will carry forward indefinitely. The change in the valuation allowance is a decrease of $9.0 million for the year ended December 31, 2017 and an increase of $10.2 million for the years ended December 31, 2016 and 2015. The Company recognizes the impact of uncertain income tax positions 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 the Company’s unrecognized tax benefits: 2017 2016 2015 Balance at beginning of year $ 1,318,839 $ 981,380 $ 571,194 Additions based on tax positions related to the current year 613,589 337,459 337,862 Additions for tax positions of prior years — — 72,324 Balance at end of year $ 1,932,428 $ 1,318,839 $ 981,380 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, 2017, 2016 and 2015, the Company has not recognized any interest or penalties related to income taxes. |
Collaboration and License Agree
Collaboration and License Agreements | 12 Months Ended |
Dec. 31, 2017 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Collaboration and License Agreements | 9. Collaboration and License Agreements In December 2016, the Company entered into the Collaboration Agreement with Novartis, pursuant to which the Company granted Novartis an exclusive option to collaborate with the Company to develop products containing emricasan. Pursuant to the Collaboration Agreement, the Company received a non-refundable upfront payment of $50.0 million from Novartis. In May 2017, Novartis exercised its option under the Collaboration Agreement. In July 2017, the Company received a $7.0 million option exercise payment, at which time the license under the Collaboration Agreement became effective (the License Effective Date). Under the Collaboration Agreement, the Company is eligible to receive up to an aggregate of $650.0 million in milestone payments over the term of the Collaboration Agreement, contingent on the achievement of certain development, regulatory and commercial milestones, as well as royalties or profit and loss sharing on future product sales in the United States, if any. Pursuant to the Collaboration Agreement, the Company is responsible for completing its four ongoing Phase 2b trials. Novartis will generally pay 50% of the Company’s Phase 2b and observational study costs pursuant to an agreed upon budget. Upon completion of the ongoing Phase 2b trials, Novartis will assume 100% of the observational study costs. Novartis will assume full responsibility for emricasan’s Phase 3 development and all combination product development. Unless terminated earlier, the Collaboration Agreement will remain in effect on a product-by-product and country-by-country basis until Novartis’ royalty obligations expire. Novartis has certain termination rights in the event of a mandated clinical trial hold for any product containing emricasan as its sole active ingredient. Additionally, Novartis has the right to terminate the Collaboration Agreement without cause upon 180 days prior written notice to the Company. In such event, the license granted to Novartis will be terminated and revert to the Company. In the event Novartis terminates the Collaboration Agreement due to the Company’s uncured material breach or insolvency, the license granted to Novartis pursuant to the Collaboration Agreement will become irrevocable, and Novartis will be required to continue to make all milestone and royalty payments otherwise due to the Company under the Collaboration Agreement, provided that if the Company materially breaches the Collaboration Agreement such that the rights licensed to Novartis or the commercial prospects of the emricasan products are seriously impaired, the milestone and royalty payments will be reduced by 50%. Under the relevant accounting literature, the Collaboration Agreement meets the definition of a collaborative arrangement and a multiple-element arrangement. The Company concluded that there were two significant deliverables under the Collaboration Agreement – the option to obtain the license and the research and development services – but that the license does not have stand-alone value as Novartis cannot obtain value from the license without the research and development services, which the Company is uniquely able to perform. As such, the Company recognized as collaboration revenue a portion of the upfront payment received of $50.0 million, the option exercise fee of $7.0 million, and the imputed income from the Investment Agreement as described below on a straight-line basis between the inception of the agreement (or with respect to the option exercise fee, upon exercise of the option) through November 2019 – the estimated period over which the Company expects to perform the research and development services. Due to the inherently unpredictable nature of product development activities, the Company periodically reviewed the performance period of the research and development services and adjusted the period over which revenue was recognized when appropriate. Expense reimbursements for the Company’s emricasan development costs were recognized as collaboration revenue when the related expenses were incurred. In the first quarter of 2018, the Company will adopt new accounting guidance that will change future patterns of revenue recognition. Under the Investment Agreement, the Company is able to borrow up to $15.0 million at a rate of 6% per annum, under one or two notes, which will mature on December 31, 2019. The Company may elect at its sole discretion to convert all or part of the outstanding principal and accrued interest into fully paid shares of common stock, at 120% of the 20-day trailing average closing price per share of the common stock immediately prior to the conversion date. Novartis has the option to convert all or part of the note(s) into shares of the Company’s common stock upon a change in control of the Company or termination of the Collaboration Agreement by Novartis pursuant to certain provisions. In the event the conversion of the notes would exceed the lesser of 19.0% of the Company’s outstanding shares on a fully-diluted basis (i) at the inception of the Investment Agreement or (ii) on the conversion date, then only the lesser amount shall convert into shares of common stock and Novartis shall be repaid in cash for any remaining principal and unpaid interest after such conversion. This ability to borrow and repay the debt at a discount using shares of the Company’s common stock was deemed to be additional, foregone revenue attributable to the Collaboration Agreement, which the Company imputed and recorded as both a receivable from Novartis and a liability (deferred revenue) of $2.5 million at the inception of the Collaboration Agreement and the Investment Agreement. On February 15, 2017, the Company issued the Novartis Note in the principal amount of $15.0 million and recorded the $15.0 million proceeds as a convertible note payable in the amount of $12.5 million and a reduction of the outstanding receivable from Novartis of $2.5 million. |
Employee Benefits
Employee Benefits | 12 Months Ended |
Dec. 31, 2017 | |
Postemployment Benefits [Abstract] | |
Employee Benefits | 10. 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, 2017 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments | 11. 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 and 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 increases approximately 3% annually from $32,784 in 2015 to $39,268 in 2020. Future minimum payments under this noncancelable operating lease total $1.2 million at December 31, 2017. Rent expense was $378,005, $378,005 and $339,053 for the years ended December 31, 2017, 2016 and 2015, 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 Pharmaceuticals, Inc., which was subsequently spun off to the Company’s stockholders in January 2013. Under the stock purchase agreement, the Company may be required to make payments to Pfizer totaling $18.0 million upon the achievement of specified regulatory milestones. |
Quarterly Financial Data
Quarterly Financial Data | 12 Months Ended |
Dec. 31, 2017 | |
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. 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenues $ 6,998,076 $ 10,008,431 $ 9,565,890 $ 8,804,399 Total operating expenses 10,688,736 15,412,109 13,614,532 13,211,903 Total other income (expense) 67,915 (13,209 ) 48,264 51,101 Net loss (3,622,745 ) (5,416,887 ) (4,000,378 ) (4,356,403 ) Net loss per share, basic and diluted (1) (0.14 ) (0.19 ) (0.13 ) (0.15 ) 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenues $ — $ — $ — $ 799,046 Total operating expenses 7,274,589 6,484,622 6,894,868 9,976,735 Total other income 2,705 13,477 27,958 54,187 Net loss (7,271,884 ) (6,471,145 ) (6,866,910 ) (9,123,502 ) Net loss per share, basic and diluted (1) (0.35 ) (0.30 ) (0.31 ) (0.35 ) (1) |
Summary of Significant Accoun19
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2017 | |
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. 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, 2017, 2016 and 2015. 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 period 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, 2017, 2016 and 2015, 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, 2017. |
Revenue Recognition | Revenue Recognition The Company recognizes revenue when each of the following four criteria is met: (i) persuasive evidence of an arrangement exists; (ii) products are delivered or as services are rendered; (iii) the sales price is fixed or determinable; and (iv) collectability is reasonably assured. The Company recognizes revenue under its Option, Collaboration and License Agreement (the Collaboration Agreement) with Novartis Pharma AG (Novartis) based on the relevant accounting literature. Under this guidance, multiple elements or deliverables may include (i) grants of licenses, or options to obtain licenses, to intellectual property, (ii) research and development services, (iii) participation on joint research and/or joint development committees, and/or (iv) manufacturing or supply services. The payments entities may receive under these arrangements typically include one or more of the following: non-refundable, upfront license fees; option exercise fees; funding of research and/or development efforts; amounts due upon the achievement of specified objectives; and/or royalties on future product sales. Multiple-element arrangements require the separability of deliverables included in an arrangement into different units of accounting and the allocation of arrangement consideration to the units of accounting. The evaluation of multiple-element arrangements requires management to make judgments about (i) the identification of deliverables, (ii) whether such deliverables are separable from the other aspects of the contractual relationship, (iii) the estimated selling price of each deliverable, and (iv) the expected period of performance for each deliverable. To determine the units of accounting under a multiple-element arrangement, management evaluates certain separation criteria, including whether the deliverables have stand-alone value, based on the relevant facts and circumstances for each arrangement. Management then estimates the selling price for each unit of accounting and allocates the arrangement consideration to each unit using the relative selling price method. The allocated consideration for each unit of accounting is recognized based on the method most appropriate for that unit of account and in accordance with the revenue recognition criteria detailed above. If there are deliverables in an arrangement that are not separable from other aspects of the contractual relationship, they are treated as a combined unit of accounting, with the allocated revenue for the combined unit recognized in a manner consistent with the revenue recognition applicable to the final deliverable in the combined unit. Payments received prior to satisfying the relevant revenue recognition criteria are recorded as deferred revenue in the accompanying balance sheets and recognized as revenue when the related revenue recognition criteria are met. The Collaboration Agreement provides for non-refundable milestone payments. The Company recognizes revenue that is contingent upon the achievement of a substantive milestone in its entirety in the period in which the milestone is achieved. A milestone is considered substantive when the consideration payable to the Company for such milestone (i) is consistent with the Company’s performance necessary to achieve the milestone or the increase in value to the collaboration resulting from the Company’s performance, (ii) relates solely to the Company’s past performance and (iii) is reasonable relative to all of the other deliverables and payments within the arrangement. In making this assessment, the Company considers all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. The Company periodically reviewed the estimated performance periods under the Collaboration Agreement, which provides for non-refundable upfront payments and fees. The Company adjusted the periods over which revenue was recognized when appropriate to reflect changes in assumptions relating to the estimated performance periods. In the first quarter of 2018, the Company will adopt new accounting guidance that will change future patterns of revenue recognition. The Company records revenues related to the reimbursement of costs incurred under the Collaboration Agreement where the Company acts as a principal, controls the research and development activities and bears credit risk. Under the Collaboration Agreement, the Company is reimbursed for associated out-of-pocket costs and for a certain amount of the Company’s full-time equivalent (FTE) costs based on an agreed-upon FTE rate. The gross amount of these pass-through reimbursed costs is reported as revenue in the accompanying statements of operations and comprehensive loss, while the actual expenses for which the Company is reimbursed are reflected as research and development costs. In the first quarter of 2018, the Company will adopt new accounting guidance that will change future patterns of revenue recognition. See Note 9 – Collaboration and License Agreements for further information. |
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, 2017, 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, 2017, 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, and forfeitures are recognized as they occur. 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, 2017 2016 2015 Assumptions Risk-free interest rate 1.83% - 2.13% 1.15% - 1.55% 1.54% - 1.94% Expected dividend yield 0% 0% 0% Expected volatility 93% - 97% 84% 72% - 89% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 5.5 - 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. |
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 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, 2017 2016 2015 Warrants to purchase common stock 149,704 149,704 149,704 Common stock options issued and outstanding 4,826,330 3,393,813 2,464,849 Shares issuable upon conversion of convertible note payable 2,965,078 — — Common stock subject to repurchase — — 32,246 ESPP shares pending issuance 4,842 2,659 5,103 Total 7,945,954 3,546,176 2,651,902 |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606). In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718). In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718). |
Summary of Significant Accoun20
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
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, 2017 2016 2015 Assumptions Risk-free interest rate 1.83% - 2.13% 1.15% - 1.55% 1.54% - 1.94% Expected dividend yield 0% 0% 0% Expected volatility 93% - 97% 84% 72% - 89% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 5.5 - 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, 2017 2016 2015 Warrants to purchase common stock 149,704 149,704 149,704 Common stock options issued and outstanding 4,826,330 3,393,813 2,464,849 Shares issuable upon conversion of convertible note payable 2,965,078 — — Common stock subject to repurchase — — 32,246 ESPP shares pending issuance 4,842 2,659 5,103 Total 7,945,954 3,546,176 2,651,902 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Fair Value Disclosures [Abstract] | |
Summary of Assets Measured at Fair Value | Below is a summary of assets, including cash equivalents and marketable securities, measured at fair value as of December 31, 2017 and 2016. Fair Value Measurements Using December 31, 2017 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 $ 12,217,656 $ 12,217,656 $ — $ — Corporate debt securities 61,774,107 — 61,774,107 — Total $ 73,991,763 $ 12,217,656 $ 61,774,107 $ — Fair Value Measurements Using December 31, 2016 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 $ 45,523,208 $ 45,523,208 $ — $ — Corporate debt securities 27,702,317 — 27,702,317 — Total $ 73,225,525 $ 45,523,208 $ 27,702,317 $ — |
Marketable Securities (Tables)
Marketable Securities (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
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, 2017 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 58,851,487 $ 312 $ (77,388 ) $ 58,774,411 Total $ 58,851,487 $ 312 $ (77,388 ) $ 58,774,411 As of December 31, 2016 Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Corporate debt securities 1 or less $ 18,937,860 $ 901 $ (7,046 ) $ 18,931,715 Total $ 18,937,860 $ 901 $ (7,046 ) $ 18,931,715 |
Property and Equipment (Tables)
Property and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Property Plant And Equipment [Abstract] | |
Schedule of Property and Equipment | Property and equipment consist of the following: December 31, 2017 2016 Furniture and fixtures $ 333,670 $ 333,670 Computer equipment and office equipment 143,059 119,354 Leasehold improvements 152,217 152,217 628,946 605,241 Less accumulated depreciation and amortization (450,297 ) (343,795 ) Total $ 178,649 $ 261,446 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
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, 2017. Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Outstanding at December 31, 2014 1,859,034 $ 6.84 Granted 822,250 6.03 Exercised (21,029 ) 1.04 Forfeited/cancelled/expired (195,406 ) 7.79 Outstanding at December 31, 2015 2,464,849 6.54 Granted 1,132,500 1.96 Exercised (60,807 ) 0.92 Forfeited/cancelled/expired (142,729 ) 6.65 Outstanding at December 31, 2016 3,393,813 5.10 Granted 1,732,600 4.91 Exercised (78,568 ) 1.32 Forfeited/cancelled/expired (221,515 ) 6.09 Outstanding at December 31, 2017 4,826,330 $ 5.05 7.60 Vested or expected to vest at December 31, 2017 4,464,279 $ 5.06 7.50 Exercisable at December 31, 2017 2,540,481 $ 5.50 6.51 |
Summary of Common Stock Reserved for Future Issuance | The following shares of common stock were reserved for future issuance at December 31, 2017 and 2016: December 31, 2017 2016 Warrants to purchase common stock 149,704 149,704 Common stock options issued and outstanding 4,826,330 3,393,813 Common stock authorized for future option grants 614,106 600,191 Common stock authorized for the ESPP 530,907 555,210 Shares issuable upon conversion of convertible note payable 2,965,078 — Total 9,086,125 4,698,918 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Income Tax Disclosure [Abstract] | |
Components of Company's Deferred Tax Assets | Significant components of the Company’s deferred tax assets at December 31, 2017 and 2016 are shown below: December 31, 2017 2016 Deferred tax assets Net operating loss carryovers $ 25,202,000 $ 41,103,000 Research and development tax credits 7,529,000 4,989,000 Intangibles 480,000 643,000 Stock options 1,840,000 2,071,000 Compensation 406,000 786,000 Other 5,667,000 486,000 Total gross deferred tax assets 41,124,000 50,078,000 Less valuation allowance (41,124,000 ) (50,078,000 ) 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, 2017, 2016 and 2015 is as follows: December 31, 2017 2016 2015 Statutory rate 34.00 % 34.00 % 34.00 % State tax, net of federal benefit 0.00 % 0.00 % 5.83 % Valuation allowance 51.50 % (34.26 %) (42.48 %) Federal tax rate change (93.30 %) 0.00 % 0.00 % General business credits 10.80 % 0.00 % 0.00 % Other (3.00 %) 0.26 % 2.65 % Effective tax rate — % — % — % |
Unrecognized Tax Benefits | The following table summarizes the activity related to the Company’s unrecognized tax benefits: 2017 2016 2015 Balance at beginning of year $ 1,318,839 $ 981,380 $ 571,194 Additions based on tax positions related to the current year 613,589 337,459 337,862 Additions for tax positions of prior years — — 72,324 Balance at end of year $ 1,932,428 $ 1,318,839 $ 981,380 |
Quarterly Financial Data (Table
Quarterly Financial Data (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
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. 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenues $ 6,998,076 $ 10,008,431 $ 9,565,890 $ 8,804,399 Total operating expenses 10,688,736 15,412,109 13,614,532 13,211,903 Total other income (expense) 67,915 (13,209 ) 48,264 51,101 Net loss (3,622,745 ) (5,416,887 ) (4,000,378 ) (4,356,403 ) Net loss per share, basic and diluted (1) (0.14 ) (0.19 ) (0.13 ) (0.15 ) 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Total revenues $ — $ — $ — $ 799,046 Total operating expenses 7,274,589 6,484,622 6,894,868 9,976,735 Total other income 2,705 13,477 27,958 54,187 Net loss (7,271,884 ) (6,471,145 ) (6,866,910 ) (9,123,502 ) Net loss per share, basic and diluted (1) (0.35 ) (0.30 ) (0.31 ) (0.35 ) (1) |
Organization and Basis of Pre27
Organization and Basis of Presentation - Additional Information (Detail) - USD ($) | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | ||
Date of incorporation | Jul. 13, 2005 | |
Accumulated deficit | $ 168,006,865 | $ 150,632,452 |
Cash, cash equivalents and marketable securities | 74,900,000 | |
Working capital | $ 51,100,000 |
Summary of Significant Accoun28
Summary of Significant Accounting Policies - Additional Information (Detail) | 12 Months Ended | ||
Dec. 31, 2017USD ($)Segment | Dec. 31, 2016USD ($) | Dec. 31, 2015USD ($) | |
Summary Of Significant Accounting Policies [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 that would, if recognized, affect the Company’s effective tax rate | $ 0 | ||
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. | ||
Number of operating segment | Segment | 1 | ||
ASU No. 2014-09 [Member] | Pro Forma [Member] | |||
Summary Of Significant Accounting Policies [Line Items] | |||
Expected net increase in accumulated deficit | $ 600,000 | ||
Minimum [Member] | |||
Summary Of Significant Accounting Policies [Line Items] | |||
Estimated useful lives of the assets | 3 years | ||
Maximum [Member] | |||
Summary Of Significant Accounting Policies [Line Items] | |||
Estimated useful lives of the assets | 5 years |
Summary of Significant Accoun29
Summary of Significant Accounting Policies - Schedule of Black-Scholes Option Pricing Model Assumptions (Detail) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Risk-free interest rate - Minimum | 1.83% | 1.15% | 1.54% |
Risk-free interest rate - Maximum | 2.13% | 1.55% | 1.94% |
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Expected volatility | 84.00% | ||
Expected volatility - Minimum | 93.00% | 72.00% | |
Expected volatility - Maximum | 97.00% | 89.00% | |
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 | 5 years 6 months |
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 Accoun30
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, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 7,945,954 | 3,546,176 | 2,651,902 |
ESPP shares pending issuance [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 4,842 | 2,659 | 5,103 |
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 | 4,826,330 | 3,393,813 | 2,464,849 |
Shares issuable upon conversion of convertible note payable [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 2,965,078 | 0 | 0 |
Common stock subject to repurchase [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Outstanding potentially dilutive securities | 0 | 0 | 32,246 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Assets Measured at Fair Value (Detail) - USD ($) | Dec. 31, 2017 | Dec. 31, 2016 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | $ 73,991,763 | $ 73,225,525 |
Money market funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 12,217,656 | 45,523,208 |
Corporate debt securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 61,774,107 | 27,702,317 |
Level 1 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 12,217,656 | 45,523,208 |
Level 1 [Member] | Money market funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 12,217,656 | 45,523,208 |
Level 1 [Member] | Corporate debt securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 0 | 0 |
Level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 61,774,107 | 27,702,317 |
Level 2 [Member] | Money market funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 0 | 0 |
Level 2 [Member] | Corporate debt securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 61,774,107 | 27,702,317 |
Level 3 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 0 | 0 |
Level 3 [Member] | Money market funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | 0 | 0 |
Level 3 [Member] | Corporate debt securities [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets fair value | $ 0 | $ 0 |
Marketable Securities - Summary
Marketable Securities - Summary of Marketable Securities (Detail) - USD ($) | Dec. 31, 2017 | Dec. 31, 2016 |
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 58,851,487 | $ 18,937,860 |
Unrealized Gains | 312 | 901 |
Unrealized Losses | (77,388) | (7,046) |
Estimated Fair Value | 58,774,411 | 18,931,715 |
Corporate debt securities 1 or less years of maturity [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 58,851,487 | 18,937,860 |
Unrealized Gains | 312 | 901 |
Unrealized Losses | (77,388) | (7,046) |
Estimated Fair Value | $ 58,774,411 | $ 18,931,715 |
Property and Equipment - Schedu
Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) | Dec. 31, 2017 | Dec. 31, 2016 |
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 628,946 | $ 605,241 |
Less accumulated depreciation and amortization | (450,297) | (343,795) |
Total | 178,649 | 261,446 |
Furniture and fixtures [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 333,670 | 333,670 |
Computer equipment and office equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 143,059 | 119,354 |
Leasehold improvements [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 152,217 | $ 152,217 |
Property and Equipment - Additi
Property and Equipment - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Property Plant And Equipment [Abstract] | |||
Depreciation | $ 108,303 | $ 105,841 | $ 67,856 |
Notes Payable - Additional Info
Notes Payable - Additional Information (Detail) | Feb. 15, 2017USD ($)d | Jan. 24, 2017USD ($) | Dec. 31, 2017USD ($) | Dec. 19, 2016USD ($) | Jul. 31, 2010USD ($) |
Debt Instrument [Line Items] | |||||
Convertible note payable | $ 13,200,000 | ||||
Novartis [Member] | Investment Agreement [Member] | |||||
Debt Instrument [Line Items] | |||||
Deferred revenue | $ 2,500,000 | ||||
Novartis [Member] | Investment Agreement [Member] | Maximum [Member] | |||||
Debt Instrument [Line Items] | |||||
Percentage of outstanding shares will receive upon debt instrument conversion | 19.00% | ||||
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 | ||||
Prepayment of notes payable | $ 1,004,861 | ||||
Convertible Promissory Note [Member] | Novartis [Member] | |||||
Debt Instrument [Line Items] | |||||
Debt instrument, interest rate | 6.00% | ||||
Debt instrument, maturity date | Dec. 31, 2019 | ||||
Promissory note, principal amount | $ 15,000,000 | ||||
Promissory note conversion, description | Novartis has the option to convert all or part of the Novartis Note into shares of the Company’s common stock upon a change in control of the Company or termination of the Collaboration Agreement by Novartis pursuant to certain provisions. If converted, the principal and accrued interest under the Novartis Note will convert into the Company’s common stock at a conversion price equal to 120% of the 20-day trailing average closing price per share of the common stock immediately prior to the conversion date. In the event the aggregate number of shares of common stock issued upon the conversion would exceed the lesser of 19.0% of the Company’s outstanding shares on a fully-diluted basis (i) at the inception of the Investment Agreement or (ii) on the conversion date, then only the lesser amount shall convert into shares of common stock and Novartis shall be repaid in cash for any remaining principal and unpaid interest after such conversion. Upon the occurrence of certain events of default, the Novartis Note requires the Company to repay the principal balance of the Novartis Note and any unpaid accrued interest. | ||||
Principal and accrued interest of note to be converted into common stock at conversion price, in percentage | 120.00% | ||||
Trailing period for average closing price per share of common stock | d | 20 | ||||
Proceeds from issuance of convertible note payable | $ 15,000,000 | ||||
Convertible note payable | 12,500,000 | ||||
Reduction of outstanding receivable | $ 2,500,000 | ||||
Fair value of convertible note payable | $ 13,200,000 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Detail) - USD ($) | Aug. 31, 2017 | May 31, 2017 | Apr. 30, 2015 | Aug. 31, 2014 | Jul. 31, 2013 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2013 |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Common stock, value of shares issued | $ 3,003 | $ 2,612 | |||||||
Net proceeds from the issuance of common stock | $ 30,600,000 | $ 21,400,000 | 30,609,789 | 13,521,913 | $ 22,305,226 | ||||
Payment for repurchase of common stock | $ 11,202,542 | $ 0 | $ 0 | ||||||
Warrants exercisable, outstanding | 149,704 | 149,704 | |||||||
Total remaining options available for future grant | 614,106 | 600,191 | |||||||
Stock options granted to purchase common stock | 1,732,600 | 1,132,500 | 822,250 | ||||||
Weighted-average fair value of options granted | $ 3.79 | $ 1.38 | $ 4.31 | ||||||
Total intrinsic value of stock options exercised | $ 300,000 | $ 100,000 | $ 100,000 | ||||||
Intrinsic value of options outstanding | 4,300,000 | ||||||||
Intrinsic value of options vested or expected to vest | 4,200,000 | ||||||||
Intrinsic value of options exercisable | $ 2,900,000 | ||||||||
Common stock, shares issued | 30,034,757 | 26,118,722 | |||||||
Accounts payable and accrued expenses | $ 11,961,983 | $ 5,311,093 | |||||||
Stock-based compensation | 4,098,392 | $ 3,353,456 | $ 3,315,943 | ||||||
Unrecognized compensation expense | $ 6,700,000 | ||||||||
Weighted-average vesting term | 2 years 6 months | ||||||||
Employment Inducement Award [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Stock options granted to purchase common stock | 525,000 | ||||||||
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% | ||||||||
Total remaining options available for future grant | 614,106 | ||||||||
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% | ||||||||
2013 Warrants [Member] | Convertible promissory notes [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 0 | ||||||||
Exercise price of warrant per share | $ 0 | ||||||||
Warrants exercisable, outstanding | 0 | ||||||||
Warrant expiration date | May 30, 2018 | ||||||||
2013 Warrants [Member] | Series B Preferred Stock [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 1,124,026 | ||||||||
Exercise price of warrant per share | $ 0 | ||||||||
Warrants exercisable, outstanding | 0 | ||||||||
2013 Warrants [Member] | Series B Preferred Stock [Member] | Convertible promissory notes [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 0 | ||||||||
Exercise price of warrant per share | $ 0 | $ 0.90 | |||||||
Warrants exercisable, outstanding | 0 | ||||||||
Lender Warrants [Member] | Series B convertible preferred stock [Member] | Term Loan One | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 0 | ||||||||
Exercise price of warrant per share | $ 0 | $ 0.90 | |||||||
Warrant issued | 111,112 | ||||||||
Warrants exercisable, outstanding | 0 | ||||||||
Warrant expiration date | Jul. 3, 2023 | ||||||||
Common Stock [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Common stock, shares issued | 5,980,000 | 6,155,721 | 4,174,805 | ||||||
Common Stock [Member] | 2013 Warrants [Member] | Convertible promissory notes [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 0 | ||||||||
Exercise price of warrant per share | $ 7.43 | ||||||||
Warrants exercisable, outstanding | 0 | ||||||||
Common Stock [Member] | Lender Warrants [Member] | Convertible promissory notes [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 0 | ||||||||
Exercise price of warrant per share | $ 7.43 | ||||||||
Warrants exercisable, outstanding | 13,468 | ||||||||
Follow on Offering [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Common stock, shares issued | 5,980,000 | 4,025,000 | |||||||
Common stock, price per share | $ 5.50 | $ 5.75 | |||||||
Post IPO [Member] | Common Stock [Member] | 2013 Warrants [Member] | Convertible promissory notes [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Warrant exercisable to purchase shares | 0 | ||||||||
Exercise price of warrant per share | $ 0 | ||||||||
Warrants exercisable, outstanding | 136,236 | ||||||||
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 | 24,303 | 26,876 | 17,914 | ||||||
Accounts payable and accrued expenses | $ 16,367 | $ 4,521 | $ 15,789 | ||||||
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 | 6,155,721 | 149,805 | |||||||
Net proceeds from the issuance of common stock | $ 600,000 | $ 13,500,000 | |||||||
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 | $ 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 | $ 2.26 | $ 6.05 | |||||||
Stock Purchase Agreement with Advent [Member] | Common Stock [Member] | |||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||
Common stock, price per share | $ 5.17 | ||||||||
Payment for repurchase of common stock | $ 11,200,000 | ||||||||
Shares repurchased and retired under stock purchase agreement | 2,166,836 |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of Stock Option Activity (Detail) - $ / shares | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |||
Number of Options, Beginning balance | 3,393,813 | 2,464,849 | 1,859,034 |
Number of Options, Granted | 1,732,600 | 1,132,500 | 822,250 |
Number of Options, Exercised | (78,568) | (60,807) | (21,029) |
Number of Options, Forfeited/cancelled/expired | (221,515) | (142,729) | (195,406) |
Number of Options, Ending balance | 4,826,330 | 3,393,813 | 2,464,849 |
Number of Options, Vested or expected to vest | 4,464,279 | ||
Number of Options, Exercisable | 2,540,481 | ||
Weighted-Average Exercise Price, Beginning balance | $ 5.10 | $ 6.54 | $ 6.84 |
Weighted-Average Exercise Price, Granted | 4.91 | 1.96 | 6.03 |
Weighted-Average Exercise Price, Exercised | 1.32 | 0.92 | 1.04 |
Weighted-Average Exercise Price, Forfeited/cancelled/expired | 6.09 | 6.65 | 7.79 |
Weighted-Average Exercise Price, Ending balance | 5.05 | $ 5.10 | $ 6.54 |
Weighted-Average Exercise Price, Vested | 5.06 | ||
Weighted-Average Exercise Price, Vested, Exercisable | $ 5.50 | ||
Weighted-Average Remaining Contractual Term Outstanding | 7 years 7 months 6 days | ||
Weighted-Average Remaining Contractual Term Vested or expected to vest | 7 years 6 months | ||
Weighted-Average Remaining Contractual Term Exercisable | 6 years 6 months 3 days |
Stockholders' Equity - Summar38
Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Detail) - shares | Dec. 31, 2017 | Dec. 31, 2016 |
Equity [Abstract] | ||
Warrants to purchase common stock | 149,704 | 149,704 |
Common stock options issued and outstanding | 4,826,330 | 3,393,813 |
Common stock authorized for future option grants | 614,106 | 600,191 |
Common stock authorized for the ESPP | 530,907 | 555,210 |
Shares issuable upon conversion of convertible note payable | 2,965,078 | 0 |
Total | 9,086,125 | 4,698,918 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | Jul. 13, 2013 | Oct. 27, 2006 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 |
Operating Loss Carryforwards [Line Items] | ||||||
Federal corporate income tax rate | 34.00% | 34.00% | 34.00% | |||
Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit) | $ 16.2 | |||||
Cumulative change in ownership percentage | 50.00% | |||||
Period for cumulative change in ownership percentage | 3 years | |||||
Research credit carryforwards expiration year | 2,027 | |||||
Deferred tax asset, change in valuation allowance amount | $ (9) | $ 10.2 | $ 10.2 | |||
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 | 94.6 | |||||
Research credit carryforwards | $ 7.7 | |||||
Operating loss carryforwards expiration year | 2,028 | |||||
California [Member] | ||||||
Operating Loss Carryforwards [Line Items] | ||||||
Operating loss carryforwards | $ 4.2 | |||||
Operating loss carryforwards expiration year | 2,017 | |||||
State [Member] | ||||||
Operating Loss Carryforwards [Line Items] | ||||||
Operating loss carryforwards | $ 76.4 | |||||
Research credit carryforwards | $ 2 | |||||
Operating loss carryforwards expiration year | 2,015 | |||||
IPO [Member] | ||||||
Operating Loss Carryforwards [Line Items] | ||||||
Cumulative change in ownership percentage | 50.00% | |||||
Series A Preferred Stock [Member] | ||||||
Operating Loss Carryforwards [Line Items] | ||||||
Cumulative change in ownership percentage | 50.00% | |||||
Maximum [Member] | ||||||
Operating Loss Carryforwards [Line Items] | ||||||
Federal corporate income tax rate | 35.00% | |||||
Scenario, Plan [Member] | ||||||
Operating Loss Carryforwards [Line Items] | ||||||
Federal corporate income tax rate | 21.00% |
Income Taxes - Components of Co
Income Taxes - Components of Company's Deferred Tax Assets (Detail) - USD ($) | Dec. 31, 2017 | Dec. 31, 2016 |
Deferred tax assets | ||
Net operating loss carryovers | $ 25,202,000 | $ 41,103,000 |
Research and development tax credits | 7,529,000 | 4,989,000 |
Intangibles | 480,000 | 643,000 |
Stock options | 1,840,000 | 2,071,000 |
Compensation | 406,000 | 786,000 |
Other | 5,667,000 | 486,000 |
Total gross deferred tax assets | 41,124,000 | 50,078,000 |
Less valuation allowance | $ (41,124,000) | (50,078,000) |
Net deferred tax assets | $ 0 |
Income Taxes - Reconciliation o
Income Taxes - Reconciliation of Statutory Tax Rates and Effective Tax Rates (Detail) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |||
Statutory rate | 34.00% | 34.00% | 34.00% |
State tax, net of federal benefit | 0.00% | 0.00% | 5.83% |
Valuation allowance | 51.50% | (34.26%) | (42.48%) |
Federal tax rate change | (93.30%) | 0.00% | 0.00% |
General business credits | 10.80% | 0.00% | 0.00% |
Other | (3.00%) | 0.26% | 2.65% |
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, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |||
Balance at beginning of year | $ 1,318,839 | $ 981,380 | $ 571,194 |
Additions based on tax positions related to the current year | 613,589 | 337,459 | 337,862 |
Additions for tax positions of prior years | 0 | 0 | 72,324 |
Balance at end of year | $ 1,932,428 | $ 1,318,839 | $ 981,380 |
Collaboration and License Agr43
Collaboration and License Agreements - Additional Information (Detail) | Feb. 15, 2017USD ($) | Dec. 31, 2016USD ($)Deliverable | Dec. 31, 2017USD ($) | Jul. 05, 2017USD ($) |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||
Convertible note payable | $ 13,200,000 | |||
Collaboration Agreement [Member] | Novartis [Member] | ||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||
Proceeds from option exercised | $ 7,000,000 | |||
Maximum milestone payments to be received upon achievement of certain milestones | $ 650,000,000 | |||
Percentage of observational study costs | 50.00% | |||
Assumed percentage of observational study costs upon completion of ongoing Phase 2b trails | 100.00% | |||
Required prior written notice period for termination of collaboration agreement | 180 days | |||
Percentage of reduction in milestone and royalty payments | 50.00% | |||
Number of significant deliverables | Deliverable | 2 | |||
Collaboration revenue recognized over the period from upfront payment received | $ 50,000,000 | |||
Collaboration revenue recognized over the period from option exercise fee | 7,000,000 | |||
Collaboration Agreement [Member] | Novartis [Member] | Upfront Payment [Member] | ||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||
Non-refundable payment received | 50,000,000 | |||
Investment Agreement [Member] | Novartis [Member] | ||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||
Debt instrument, maximum borrowing capacity | $ 15,000,000 | |||
Debt instrument, interest rate | 6.00% | |||
Debt instrument, maturity date | Dec. 31, 2019 | |||
Debt instrument, conversion price percentage | 120.00% | |||
Number of days trailing average closing price of common stock immediately prior to the conversion date | 20 days | |||
Deferred revenue | $ 2,500,000 | |||
Investment Agreement [Member] | Novartis [Member] | Convertible Promissory Note [Member] | ||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||
Principal amount of note issued | $ 15,000,000 | |||
Proceeds from issuance of convertible note payable | 15,000,000 | |||
Convertible note payable | 12,500,000 | |||
Reduction of outstanding receivable | $ 2,500,000 | |||
Investment Agreement [Member] | Novartis [Member] | Maximum [Member] | ||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||
Percentage of outstanding shares will receive upon debt instrument conversion | 19.00% |
Employee Benefits - Additional
Employee Benefits - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Postemployment Benefits [Abstract] | |||
Defined contribution plan, Employees voluntary contributions, Amount | $ 216,701 | $ 171,517 | $ 164,989 |
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, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Jul. 31, 2010 | |
Operating Leased Assets [Line Items] | |||||
Rent expense | $ 378,005 | $ 378,005 | $ 339,053 | ||
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 | $ 1,200,000 | ||||
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 |
Quarterly Financial Data - Summ
Quarterly Financial Data - Summary of Quarterly Financial Data (Detail) - USD ($) | 3 Months Ended | 12 Months Ended | |||||||||||||||||
Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |||||||||
Quarterly Financial Information Disclosure [Abstract] | |||||||||||||||||||
Total revenues | $ 8,804,399 | $ 9,565,890 | $ 10,008,431 | $ 6,998,076 | $ 799,046 | $ 0 | $ 0 | $ 0 | $ 35,376,796 | $ 799,046 | $ 0 | ||||||||
Total operating expenses | 13,211,903 | 13,614,532 | 15,412,109 | 10,688,736 | 9,976,735 | 6,894,868 | 6,484,622 | 7,274,589 | 52,927,280 | 30,630,814 | 24,130,702 | ||||||||
Total other income (expense) | 51,101 | 48,264 | (13,209) | 67,915 | 54,187 | 27,958 | 13,477 | 2,705 | 154,071 | 98,327 | (17,924) | ||||||||
Net loss | $ (4,356,403) | $ (4,000,378) | $ (5,416,887) | $ (3,622,745) | $ (9,123,502) | $ (6,866,910) | $ (6,471,145) | $ (7,271,884) | $ (17,396,413) | $ (29,733,441) | $ (24,148,626) | ||||||||
Net loss per share, basic and diluted | $ (0.15) | [1] | $ (0.13) | [1] | $ (0.19) | [1] | $ (0.14) | [1] | $ (0.35) | [1] | $ (0.31) | [1] | $ (0.30) | [1] | $ (0.35) | [1] | $ (0.61) | $ (1.31) | $ (1.30) |
[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. |