Document and Entity Information
Document and Entity Information - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Mar. 01, 2019 | Jun. 30, 2018 | |
Document And Entity Information [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2018 | ||
Document Fiscal Year Focus | 2,018 | ||
Document Fiscal Period Focus | FY | ||
Trading Symbol | AGLE | ||
Entity Registrant Name | Aeglea BioTherapeutics, Inc. | ||
Entity Central Index Key | 1,636,282 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Filer Category | Accelerated Filer | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Common Stock Shares Outstanding | 28,819,900 | ||
Entity Public Float | $ 199.1 | ||
Entity Shell Company | false | ||
Entity Emerging Growth Company | true | ||
Entity Ex Transition Period | true | ||
Entity Small Business | false |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) | Dec. 31, 2018 | Dec. 31, 2017 |
CURRENT ASSETS | ||
Cash and cash equivalents | $ 22,461,000 | $ 12,817,000 |
Marketable securities | 52,052,000 | 37,482,000 |
Accounts receivable - grant | 3,078,000 | |
Prepaid expenses and other current assets | 2,158,000 | 1,614,000 |
Total current assets | 76,671,000 | 54,991,000 |
Property and equipment, net | 1,018,000 | 854,000 |
Other non-current assets | 50,000 | 232,000 |
TOTAL ASSETS | 77,739,000 | 56,077,000 |
CURRENT LIABILITIES | ||
Accounts payable | 663,000 | 389,000 |
Deferred revenue | 20,000 | |
Accrued and other current liabilities | 9,576,000 | 5,220,000 |
Total current liabilities | 10,239,000 | 5,629,000 |
Other non-current liabilities | 72,000 | 111,000 |
TOTAL LIABILITIES | 10,311,000 | 5,740,000 |
Commitments and Contingencies (Note 13 and 15) | ||
STOCKHOLDERS’ EQUITY | ||
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of December 31, 2018 and 2017; no shares issued and outstanding as of December 31, 2018 and 2017 | ||
Common stock, $0.0001 par value; 500,000,000 shares authorized as of December 31, 2018 and 2017, 24,140,097 shares and 16,670,188 shares issued and outstanding as of December 31, 2018 and 2017, respectively | 2,000 | 2,000 |
Additional paid-in capital | 184,314,000 | 122,950,000 |
Accumulated other comprehensive loss | (27,000) | (102,000) |
Accumulated deficit | (116,861,000) | (72,513,000) |
TOTAL STOCKHOLDERS’ EQUITY | 67,428,000 | 50,337,000 |
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY | $ 77,739,000 | $ 56,077,000 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2018 | Dec. 31, 2017 |
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 | 500,000,000 | 500,000,000 |
Common stock, shares issued | 24,140,097 | 16,670,188 |
Common stock, shares outstanding | 24,140,097 | 16,670,188 |
Consolidated Statements of Oper
Consolidated Statements of Operations - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Revenues: | |||
Grant | $ 3,888 | $ 5,205 | $ 4,628 |
Type of revenue [extensible list] | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember |
Operating expenses: | |||
Research and development | $ 36,719 | $ 22,815 | $ 18,143 |
General and administrative | 12,632 | 10,066 | 8,391 |
Total operating expenses | 49,351 | 32,881 | 26,534 |
Loss from operations | (45,463) | (27,676) | (21,906) |
Other income (expense): | |||
Interest income | 1,172 | 482 | 244 |
Other expense | (57) | (42) | (36) |
Total other income | 1,115 | 440 | 208 |
Net loss | $ (44,348) | $ (27,236) | $ (21,698) |
Net loss per share, basic and diluted | $ (2.13) | $ (1.80) | $ (2.22) |
Weighted-average common shares outstanding, basic and diluted | 20,822,560 | 15,128,192 | 9,791,728 |
Consolidated Statements of Comp
Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Statement Of Income And Comprehensive Income [Abstract] | |||
Net loss | $ (44,348) | $ (27,236) | $ (21,698) |
Other comprehensive income (loss): | |||
Unrealized gain (loss) on marketable securities | 75 | (98) | (3) |
Total comprehensive loss | $ (44,273) | $ (27,334) | $ (21,701) |
Consolidated Statements of Chan
Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | Series A Convertible Preferred Stock | Series B Convertible Preferred Stock | Common Stock | Additional Paid-in Capital | Accumulated Deficit | Accumulated Other Comprehensive Loss |
Balances at Dec. 31, 2015 | $ (22,207) | $ 1,373 | $ (23,579) | $ (1) | |||
Balances (in shares) at Dec. 31, 2015 | 757,000 | ||||||
Temporary Equity Balances at Dec. 31, 2015 | $ 13,573 | $ 44,738 | |||||
Temporary Equity Balances (in shares) at Dec. 31, 2015 | 2,173,000 | 5,000,000 | |||||
Conversion of preferred stock to common stock upon initial public offering | 58,311 | $ (13,573) | $ (44,738) | $ 1 | 58,310 | ||
Conversion of preferred stock to common stock upon initial public offering (in shares) | (2,173,000) | (5,000,000) | 7,173,000 | ||||
Issuance of common stock in connection with initial public offering/ follow-on offering/ at-the-market offerings, net of offering costs | 47,266 | 47,266 | |||||
Issuance of common stock in connection with initial public offering/ follow-on offering/ at-the-market offerings, net of offering costs | 5,482,000 | ||||||
Issuance of common stock in connection with employee stock purchase plan | 76 | 76 | |||||
Issuance of common stock in connection with employee stock purchase plan (in shares) | 19,000 | ||||||
Stock-based compensation expense | 1,221 | 1,221 | |||||
Unrealized gain (loss) on marketable securities | (3) | (3) | |||||
Net loss | (21,698) | (21,698) | |||||
Balances at Dec. 31, 2016 | 62,966 | $ 1 | 108,246 | (45,277) | (4) | ||
Balances (in shares) at Dec. 31, 2016 | 13,431,000 | ||||||
Issuance of common stock in connection with initial public offering/ follow-on offering/ at-the-market offerings, net of offering costs | 11,380 | $ 1 | 11,379 | ||||
Issuance of common stock in connection with initial public offering/ follow-on offering/ at-the-market offerings, net of offering costs | 3,000,000 | ||||||
Issuance of common stock in connection with employee stock purchase plan | 131 | 131 | |||||
Issuance of common stock in connection with employee stock purchase plan (in shares) | 39,000 | ||||||
Issuance of common stock in connection with exercise of stock options | 702 | 702 | |||||
Issuance of common stock in connection with exercise of stock options (in shares) | 200,000 | ||||||
Stock-based compensation expense | 2,492 | 2,492 | |||||
Unrealized gain (loss) on marketable securities | (98) | (98) | |||||
Net loss | (27,236) | (27,236) | |||||
Balances at Dec. 31, 2017 | 50,337 | $ 2 | 122,950 | (72,513) | (102) | ||
Balances (in shares) at Dec. 31, 2017 | 16,670,000 | ||||||
Issuance of common stock in connection with initial public offering/ follow-on offering/ at-the-market offerings, net of offering costs | 54,048 | 54,048 | |||||
Issuance of common stock in connection with initial public offering/ follow-on offering/ at-the-market offerings, net of offering costs | 6,893,000 | ||||||
Issuance of common stock in connection with employee stock purchase plan | 207 | 207 | |||||
Issuance of common stock in connection with employee stock purchase plan (in shares) | 56,000 | ||||||
Issuance of common stock in connection with exercise of stock options | $ 2,829 | 2,829 | |||||
Issuance of common stock in connection with exercise of stock options (in shares) | 521,665 | 521,000 | |||||
Stock-based compensation expense | $ 4,280 | 4,280 | |||||
Unrealized gain (loss) on marketable securities | 75 | 75 | |||||
Net loss | (44,348) | (44,348) | |||||
Balances at Dec. 31, 2018 | $ 67,428 | $ 2 | $ 184,314 | $ (116,861) | $ (27) | ||
Balances (in shares) at Dec. 31, 2018 | 24,140,000 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
CASH FLOWS FROM OPERATING ACTIVITIES | |||
Net loss | $ (44,348) | $ (27,236) | $ (21,698) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation and amortization | 293 | 249 | 132 |
Purchase net discount (premium) on marketable securities | 907 | 9 | (146) |
Net (accretion of discount) amortization of premium on marketable securities | (593) | 75 | 101 |
Stock-based compensation | 4,280 | 2,492 | 1,221 |
Research and development services settled with stock | 107 | 15 | 110 |
Other, net | (40) | (21) | (10) |
Changes in operating assets and liabilities: | |||
Accounts receivable - grant | 3,078 | (1,863) | 482 |
Prepaid expenses and other assets | (261) | (114) | (924) |
Accounts payable | 239 | 164 | (8) |
Deferred revenue | (20) | (51) | 71 |
Accrued and other liabilities | 4,165 | 1,666 | 1,829 |
Net cash used in operating activities | (32,193) | (24,615) | (18,840) |
CASH FLOWS FROM INVESTING ACTIVITIES | |||
Purchases of property and equipment | (422) | (619) | (212) |
Purchases of marketable securities | (62,179) | (64,115) | (20,390) |
Proceeds from maturities of marketable securities | 47,370 | 42,205 | 8,446 |
Decrease in restricted cash | 80 | ||
Net cash used in investing activities | (15,231) | (22,529) | (12,076) |
CASH FLOWS FROM FINANCING ACTIVITIES | |||
Proceeds from issuance of common stock in public and at-the-market offerings, net of offering costs | 54,048 | 11,380 | 49,294 |
Proceeds from employee stock plan purchases and stock option exercises | 3,020 | 833 | 76 |
Net cash provided by financing activities | 57,068 | 12,213 | 49,370 |
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS | 9,644 | (34,931) | 18,454 |
CASH AND CASH EQUIVALENTS | |||
Beginning of period | 12,817 | 47,748 | 29,294 |
End of period | 22,461 | 12,817 | 47,748 |
Supplemental Disclosure of Non-Cash Investing and Financing Information: | |||
Unpaid amounts related to purchase of property and equipment | $ 92 | $ 57 | 172 |
Series A Convertible Preferred Stock | |||
Supplemental Disclosure of Non-Cash Investing and Financing Information: | |||
Conversion of convertible preferred stock to common stock upon initial public offering | 13,573 | ||
Series B Convertible Preferred Stock | |||
Supplemental Disclosure of Non-Cash Investing and Financing Information: | |||
Conversion of convertible preferred stock to common stock upon initial public offering | $ 44,738 |
The Company and Basis of Presen
The Company and Basis of Presentation | 12 Months Ended |
Dec. 31, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
The Company and Basis of Presentation | 1. The Company and Basis of Presentation Aeglea BioTherapeutics, Inc. (“Aeglea” or the “Company”) is a biotechnology company that designs and develops innovative human enzyme therapeutics for patients with rare genetic diseases and cancer Liquidity As of December 31, 2018, the Company had working capital of $66.4 million, an accumulated deficit of $116.9 million, and cash, cash equivalents, and marketable securities of $74.5 million. The Company has not generated any product revenues and has not achieved profitable operations. There is no assurance that profitable operations will ever be achieved, and, if achieved, could be sustained on a continuing basis. In addition, development activities, clinical and nonclinical testing, and commercialization of the Company’s products will require significant additional financing. The Company is subject to a number of risks similar to other life science companies, including, but not limited to, risks related to the successful discovery and development of product candidates, raising additional capital, development of competing drugs and therapies, protection of proprietary technology and market acceptance of the Company’s products. As a result of these and other factors and the related uncertainties, there can be no assurance of the Company’s future success. Based upon the Company’s current operating plans, the Company believes that it has sufficient resources to fund operations through the first quarter of 2021 with its existing cash, cash equivalents, and marketable securities, in conjunction with the net proceeds received from a public offering in February 2019 (see Note 16). The Company will need to secure additional funding in the future, in order to carry out all of its planned research and development activities. If the Company is unable to obtain additional financing or generate license or product revenue, the lack of liquidity could have a material adverse effect on the Company’s future prospects. Basis of Presentation The consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) as defined by the Financial Accounting Standards Board (“FASB”) and include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2018 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Such management estimates include those related to accruals of research and development related costs, fair values of preferred and common stock, stock-based compensation, and certain company income tax related items. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ significantly from those estimates. Prior to becoming a public company, the Company utilized significant estimates and assumptions in determining the fair value of its common stock. The board of directors determined the estimated fair value of common stock based on a number of objective and subjective factors, including external market conditions affecting the biotechnology industry sector, the price at which the Company sold shares of convertible preferred stock, the superior rights and preferences of securities senior to the Company’s common stock, and the marketability at the time. The Company utilized valuation methodologies in accordance with the American Institute of Certified Public Accountants Practice Guide, Audit and Accounting Practice Aid Series: Valuation of Privately-Held-Company Securities Issued as Compensation Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist of money market funds and debt securities and are stated at fair value. Marketable Securities All investments have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase. The Company may or may not hold securities with stated maturities greater than one year until maturity. All available-for-sale securities are considered available to support current operations and are classified as current assets. Unrealized gains and losses are excluded from earnings and are reported as a component of accumulated comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in other income (expense). The cost of securities sold is based on the specific-identification method. There were no realized gains or losses on marketable securities for the years ended December 31, 2018, 2017, and 2016. Interest on marketable securities is included in interest income. Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, and marketable securities. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government, U.S. government-sponsored agencies and highly rated banks, subject to certain concentration limits and restrictions on maturities. The Company’s cash, cash equivalents, and marketable securities are held by financial institutions in the United States that management believes are of high credit quality. Amounts on deposit may at times exceed federally insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents and its accounts are monitored by management to mitigate risk. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents and bond issuers. Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance that do not extend the life or improve an asset are expensed as incurred. Upon retirement or sale, the cost of disposed assets and their related accumulated depreciation and amortization are removed from the balance sheet. Any gain or loss is credited or charged to operations. The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Furniture and office equipment 5 years Computer equipment 3 years Software 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life Impairment of Long-Lived Assets Long-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable, and the carrying amount exceeds the projected discounted future cash flows arising from these assets. There were no impairments of long-lived assets for the years ended December 31, 2018, 2017, and 2016. Accrued Research and Development Costs The Company records the costs associated with research nonclinical studies, clinical trials, and manufacturing development as incurred. These costs are a significant component of the Company’s research and development expenses, with a substantial portion of the Company’s on-going research and development activities conducted by third-party service providers, including contract research and manufacturing organizations. The Company accrues for expenses resulting from obligations under agreements with contract research organizations (“CROs”), contract manufacturing organizations (“CMOs”), and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs, and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through analysis with internal personnel and external service providers as to the progress or stage of completion of the services. The Company makes significant judgments and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO, or outside service provider, the payments will be recorded as a prepaid asset which will be amortized as the contracted services are performed. As actual costs become known, the Company adjusts its accruals. Inputs, such as the services performed, the number of patients enrolled, or the study duration, may vary from the Company’s estimates, resulting in adjustments to research and development expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. The Company has not experienced any material deviations between accrued and actual research and development expenses. Leases The Company entered into lease agreements for its office and laboratory facilities. The leases are classified as operating leases. The Company records rent expense on a straight-line basis over the term of the leases and, accordingly records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. Incentives granted under the Company’s facilities leases, including allowances to fund leasehold improvements, are deferred and are recognized as adjustments to rental expense on a straight-line basis over the term of the lease. Fair Value of Financial Instruments The Company uses fair value measurements to record fair value adjustments to certain financial and non-financial assets and liabilities and to determine fair value disclosures. The accounting standards define fair value, establish a framework for measuring fair value, and require disclosures about fair value measurements. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the principal or most advantageous market in which the Company would transact are considered along with assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The accounting standard for fair value establishes a fair value hierarchy based on three levels of inputs, the first two of which are considered observable and the last unobservable, that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels of inputs that may be used to measure fair value are as follows: Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3: Valuations based on unobservable inputs to the valuation methodology and including data about assumptions that market participants would use in pricing the asset or liability based on the best information available under the circumstances. Financial instruments carried at fair value include cash, cash equivalents, and marketable securities. The carrying amount of accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. Revenue Recognition The Company’s sole source of revenue was grant revenue related to a $19.8 million research grant received from the Cancer Prevention and Research Institute of Texas (“CPRIT”), covering a four-year period from June 1, 2014 through May 31, 2018. Grant revenue was recognized when qualifying costs were incurred and there was reasonable assurance that the conditions of the award had been met for collection. Proceeds received prior to the costs being incurred or the conditions of the award being met were recognized as deferred revenue until the services were performed and the conditions of the award were met (see Note 8). Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include, but are not limited to, salaries, benefits, travel, stock-based compensation, consulting costs, contract research service costs, laboratory supplies and facilities, contract manufacturing costs, and costs paid to other third parties that conduct research and development activities on the Company’s behalf. Amounts incurred in connection with license agreements are also included in research and development expense. Certain research and development costs incurred were settled contractually by the Company issuing a variable number of the Company’s shares determined by dividing the fixed monetary amount of costs incurred by the issuance-date fair value of the issuable shares. The Company recorded research and development expense for these costs and accrued for the fixed monetary amount as an accrued liability as the services were rendered until the amount was settled. The remaining Company obligation to settle these costs with Company shares was converted to a cash-based payment through a contract amendment with the service provider. Advance payments for goods or services to be rendered in the future for use in research and development activities are recorded as a prepaid asset and expensed as the related goods are delivered or the services are performed. Stock-Based Compensation The Company recognizes the cost of stock-based awards granted to employees based on the estimated grant-date fair values of the awards. The value of the award is recognized as compensation expense on a straight-line basis over the requisite service period. Forfeitures are recognized when they occur, which may result in the reversal of compensation costs in subsequent periods as the forfeitures arise. The Company elected to early adopt ASU 2018-07, Compensation – Stock Compensation (Topic 718) effective January 1, 2018. All non-employee share-based payment awards granted prior to adoption were remeasured at fair value as of the adoption date. There was no material impact on the Company’s consolidated financial statements from the adoption. All non-employee share-based payment awards granted after adoption are measured at grant-date fair value. Compensation expense for employee and non-employee share-based payment awards with performance conditions is recognized when the performance condition is deemed probable. Income Taxes The Company and its seven wholly-owned subsidiary corporations use the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Additionally, any changes in income tax laws are immediately recognized in the year of enactment. A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense. Comprehensive Loss Comprehensive loss is the change in stockholders’ equity from transactions and other events and circumstances other than those resulting from investments by stockholders and distributions to stockholders. The Company’s other comprehensive income (loss) is currently comprised of changes in unrealized gains and losses on available-for-sale securities. Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which establishes a comprehensive new lease accounting model. The new standard: (a) clarifies the definition of a lease; (b) requires a dual approach to lease classification similar to current lease classifications; and, (c) causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use (ROU) asset. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018, with early adoption permitted. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which provides entities with an additional transition method. Under ASU 2018-11, entities have the option of initially applying Topic 842 at the adoption date, rather than at the beginning of the earliest comparative period presented, and recognizing the cumulative effect of applying the new standard as an adjustment to beginning retained earnings in the year of adoption while continuing to present all prior periods under previous lease accounting guidance. The Company elected this transition method with an adoption date of January 1, 2019. The new standard provides a number of optional practical expedients in transition. The Company plans to elect all of the available practical expedients. The Company expects that the most significant effects of adopting this standard will primarily relate to (a) the recognition of ROU assets and lease liabilities on the balance sheet in relation to its existing operating lease agreements for the office and laboratory spaces in Austin, Texas; and (b) providing significant new disclosures about leasing activities. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40) |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. The Company measures and reports certain financial instruments as assets and liabilities at fair value on a recurring basis. The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): December 31, 2018 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 7,180 $ — $ — $ 7,180 Reverse repurchase agreements — 6,250 — 6,250 Commercial paper — 53,916 — 53,916 U.S. government securities — 4,112 — 4,112 Total financial assets $ 7,180 $ 64,278 $ — $ 71,458 December 31, 2017 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 1,674 $ — $ — $ 1,674 Reverse repurchase agreements — 7,250 — 7,250 U.S. treasury securities 1,501 — — 1,501 U.S. government securities — 35,981 — 35,981 Total financial assets $ 3,175 $ 43,231 $ — $ 46,406 The Company measures the fair value of money market funds and U.S. treasury securities on quoted prices in active markets for identical asset or liabilities. The Level 2 assets include reverse repurchase agreements, commercial paper, and U.S. government securities and are valued based on quoted prices for similar assets in active markets and inputs other than quoted prices that are derived from observable market data. The Company evaluates transfers between levels at the end of each reporting period. There were no transfers between Level 1 and Level 2 during the periods presented. Valuation Approach for the Company’s Shares and Related Instruments Prior to the IPO, the Company valued its common stock and common shares by taking into consideration, among other things, its most recent valuation of common stock and common shares prepared by an unrelated third-party valuation firm in accordance with the guidance provided by the American Institute of Certified Public Accountants Practice Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation |
Cash Equivalents and Marketable
Cash Equivalents and Marketable Securities | 12 Months Ended |
Dec. 31, 2018 | |
Investments Debt And Equity Securities [Abstract] | |
Cash Equivalents and Marketable Securities | 4. Cash Equivalents and Marketable Securities The following tables summarize the estimated fair value of the Company’s cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands): December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 7,180 $ — $ — $ 7,180 Reverse repurchase agreements 6,250 — — 6,250 Commercial paper 5,977 — (1 ) 5,976 Total cash equivalents 19,407 — (1 ) 19,406 Marketable securities: Commercial paper 47,964 — (24 ) 47,940 U.S. government securities 4,114 — (2 ) 4,112 Total marketable securities $ 52,078 $ — $ (26 ) $ 52,052 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 1,674 $ — $ — $ 1,674 Reverse repurchase agreements 7,250 — — 7,250 Total cash equivalents 8,924 — — 8,924 Marketable securities: U.S. treasury securities 1,502 — (1 ) 1,501 U.S. government securities 36,082 — (101 ) 35,981 Total marketable securities $ 37,584 $ — $ (102 ) $ 37,482 The reverse repurchase agreements are settled in cash nightly, and as such are classified as cash equivalents. As of December 31, 2018 and 2017, all debt securities with an unrealized loss position have been in a loss position for less than one year. The aggregate fair value of debt securities in an unrealized loss position as of December 31, 2018 and 2017 were $45.6 million and $37.5 million, respectively, with no individual securities in a significant unrealized loss position. The Company evaluated its securities for other-than-temporary impairment and considered the decline in market value for the securities to be primarily attributable to current economic and market conditions and would not be required to sell the securities before recovery of the amortized cost basis. Based on this analysis, these marketable securities were not considered to be other-than-temporarily impaired as of December 31, 2018 and 2017. The following table summarizes the contractual maturities of the Company's marketable securities at estimated fair value (in thousands): December 31, 2018 2017 Due in one year or less $ 52,052 $ 34,498 Due in 1 - 2 years — 2,984 Total marketable securities $ 52,052 $ 37,482 The Company may sell investments at any time for use in current operations even if they have not yet reached maturity. As a result, the Company classifies marketable securities, including securities with maturities beyond twelve months as current assets. |
Property and Equipment, Net
Property and Equipment, Net | 12 Months Ended |
Dec. 31, 2018 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment, Net | 5. Property and Equipment, Net Property and equipment, net consist of the following (in thousands): December 31, 2018 2017 Laboratory equipment $ 981 $ 651 Furniture and office equipment 227 209 Computer equipment 89 111 Software 99 99 Leasehold improvements 374 271 Property and equipment, gross 1,770 1,341 Less: Accumulated depreciation and amortization (752 ) (487 ) Property and equipment, net $ 1,018 $ 854 Depreciation and amortization expense for the years ended December 31, 2018, 2017, and 2016 was $0.3 million, $0.2 million, and $0.1 million, respectively. All of the Company’s long-lived assets are located in the United States. |
Accrued and Other Current Liabi
Accrued and Other Current Liabilities | 12 Months Ended |
Dec. 31, 2018 | |
Accrued Liabilities And Other Liabilities [Abstract] | |
Accrued and Other Current Liabilities | 6. Accrued and Other Current Liabilities Accrued and other current liabilities consist of the following (in thousands): December 31, 2018 2017 Accrued compensation $ 2,643 $ 1,837 Accrued contracted research and development costs 5,993 2,552 Accrued professional and consulting fees 807 672 Accrued and other current liabilities 133 159 Total accrued and other current liabilities $ 9,576 $ 5,220 |
Convertible Preferred Stock and
Convertible Preferred Stock and Stockholders’ Equity | 12 Months Ended |
Dec. 31, 2018 | |
Equity [Abstract] | |
Convertible Preferred Stock and Stockholders’ Equity | 7. Convertible Preferred Stock and Stockholders’ Equity As of December 31, 2015, the Company had 2,172,520 shares of Series A convertible preferred stock outstanding and 4,999,976 shares of Series B convertible preferred stock outstanding with a related carrying value of $13.6 million and $44.7 million, respectively. Immediately prior to the closing of the Company’s initial public offering (“IPO”) in April 2016, all of the outstanding convertible preferred stock was automatically converted into 7,172,496 shares of common stock on a one-to-one basis, with the aggregate total carrying value of $58.3 million reclassified to common stock and additional paid-in capital. As of December 31, 2018 and 2017, there were no shares of preferred stock outstanding. On April 12, 2016, the Company closed an IPO of its common stock, which resulted in the sale of 5,481,940 shares of its common stock at a public offering price of $10.00 per share, including 481,940 shares of common stock issued upon the partial exercise by the underwriters of their option to purchase additional shares. The Company received $47.3 million in aggregate cash proceeds, net of underwriting discounts and commissions of $3.8 million and offering costs of $3.7 million incurred by the Company. In connection with the IPO, the Company amended its Restated Certificate of Incorporation to change the authorized capital stock to 510,000,000 shares of which 500,000,000 shares are designated as common stock and 10,000,000 shares are designated as preferred stock, all with a par value of $0.0001 per share. Follow-on Public Offerings In June 2017, the Company issued and sold 3,000,000 shares of common stock in an underwritten public offering pursuant to a shelf registration statement on Form S-3 at a public offering price of $4.10 per share. The net proceeds to the Company from this public offering was $11.4 million, after deducting underwriting discounts and commissions of $0.6 million and offering costs of $0.3 million. In April 2018, the Company issued and sold 5,046,510 shares of common stock in an underwritten public offering pursuant to a shelf registration statement on Form S-3 at a public offering price of $8.00 per share, including 546,510 shares of common stock issued upon the partial exercise by the underwriters of their option to purchase additional shares. The net proceeds to the Company from this public offering was $37.7 million, after deducting underwriting discounts and commissions of $2.4 million and offering costs of $0.3 million. At-The-Market Offering In May 2017, the Company entered into a sales agreement with JonesTrading Institutional Services LLC, as sales agent and underwriter, pursuant to which the Company may issue and sell shares of its common stock for an aggregate offering price of $20.0 million under an at-the-market (“ATM’) offering program. In October 2018, the Company sold 1,845,820 shares of common stock in a single transaction pursuant to the ATM at an offering price of $9.21 per share for gross proceeds of $17.0 million, resulting in net proceeds of $16.4 million after deducting underwriting fees and offering expenses. The Company subsequently terminated the ATM sales agreement with JonesTrading in December 2018 and entered into a sales agreement with Jeffries LLC, as sales agent and underwriter, to issue and sell shares of the Company’s common stock for an aggregate offering price of $60.0 million under an ATM offering program. |
Grant Revenues
Grant Revenues | 12 Months Ended |
Dec. 31, 2018 | |
Grant Revenues [Abstract] | |
Grant Revenues | 8. Grant Revenues In June 2015, the Company entered into a Cancer Research Grant Contract (“Grant Contract”) with CPRIT, under which CPRIT awarded a grant not to exceed $19.8 million for use in developing cancer treatments by exploiting the metabolism of cancer cells. The Grant Contract covered a four-year period from June 1, 2014 through May 31, 2018. Upon commercialization of the product, the terms of the Grant Contract require the Company to pay tiered royalties in the low to mid-single digit percentages. Such royalties reduce to less than one percent after a mid-single-digit multiple of the grant funds have been paid to CPRIT as royalties. The contract ended in May 2018 with the full $19.8 million grant recognized as revenue over the life of the award. For the years ended December 31, 2018, 2017, and 2016 the Company recognized $3.9 million, $5.2 million, and $4.6 million, respectively, in grant revenues for qualified expenditures under the grant. As of December 31, 2018, all grant proceeds had been collected. As of December 31, 2017, the Company had an outstanding grant receivable of $3.1 million for the grant expenditures that were paid but had not been reimbursed and deferred revenue of $20,000 for proceeds received but for which the costs had not been incurred or the conditions of the award had not been met. |
Stock-Based Compensation
Stock-Based Compensation | 12 Months Ended |
Dec. 31, 2018 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stock-Based Compensation | 9. Stock-Based Compensation 2015 Equity Incentive Plan In March 2015, the Company adopted the 2015 Equity Incentive Plan (“2015 Plan”), administered by the board of directors, and provides for the Company to sell or issue common stock or restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the board of directors and consultants of the Company. Under the terms of the 2015 Plan, the exercise prices, vesting and other restrictions may be determined at the discretion of the board of directors, or their committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant, the term of stock options may not be greater than ten years for all grants, and for grantees holding more than 10% of the total combined voting power of all classes of stock, the term may not be greater than five years. The Company granted options under the 2015 Plan until April 2016 when it was terminated as to future awards, although it continues to govern the terms of options that remain outstanding under the 2015 Plan. As of December 31, 2018, a total of 268,716 shares of common stock are subject to options outstanding under the 2015 Plan and will become available under the 2016 Equity Incentive Plan (“2016 Plan”) to the extent the options are forfeited or lapse unexercised. 2016 Equity Incentive Plan The 2016 Plan became effective in April 2016 and serves as the successor to the 2015 Plan. Under the 2016 Plan, the Company may grant stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance awards, and stock bonuses. The 2016 Plan provides for an initial reserve of 1,100,000 shares of common stock, plus 509,869 shares of common stock remaining under the 2015 Plan, and any share awards that subsequently are forfeited or lapse unexercised under the 2015 Plan. The shares reserved exclude shares of common stock reserved for issuance under the 2015 Plan. In October 2018, the 2016 plan was amended to increase the number of shares of common stock reserved for issuance thereunder by 1,759,602 shares, extend the term of the 2016 Plan through August 7, 2028, and provide for an automatic increase in the number of shares reserved for issuance thereunder on January 1 of each year for the remaining term of the plan equal to (a) 4.0% of the number of issued and outstanding shares of common stock on December 31 of the immediately preceding year, or (b) a lesser amount as approved by the board each year. The superseded 2016 Plan provision to provide an annual increase in the number of shares available for issuance required the Company’s board of directors to approve the increase, up to 4%, prior to January 1 of each relevant year. As a result of the operation of each of these provisions, on January 1, 2019, 2018, and 2017, an additional 965,603, 666,807, and 537,233 shares, respectively, became available for issuance under the 2016 Plan. As of December 31, 2018, the total number of shares reserved for issuance under the 2016 Plan was 4,750,902, of which 2,760,071 shares were subject to outstanding option awards. 2018 Equity Inducement Plan In February 2018, the board of directors approved and adopted the 2018 Equity Inducement Plan (“2018 Plan”), which became effective on the same date. The board of directors approved an initial reserve of 1,100,000 shares of common stock to be used exclusively for individuals who were not previously employees or directors, or following a bona fide period of non-employment, as an inducement material to the individual entering into employment with the Company. Nonqualified stock options or restricted stock units may be granted under the 2018 Plan at the discretion of the Compensation Committee or the board of directors. The Company did not seek stockholder approval of the 2018 Plan pursuant to Nasdaq Rule 5635(c)(4). As of December 31, 2018, the total number of shares reserved for issuance under the 2018 Plan was 1,100,000, of which 113,900 shares were subject to outstanding option awards. Under the 2016 Plan and 2018 Plan, the Company may grant stock-based awards with service conditions (“service-based” awards), performance conditions (“performance-based” awards), and market conditions (“market-based” awards). Service-based awards granted under the 2018 Plan, 2016 Plan, and 2015 Plan generally vest over four years and expire after ten years, although awards have been granted with vesting terms less than four years. 2016 Employee Stock Purchase Plan The 2016 Employee Stock Purchase Plan (“2016 ESPP”) became effective in April 2016. A total of 165,000 shares of common stock were reserved for issuance under the 2016 ESPP. Eligible employees may purchase shares of common stock under the 2016 ESPP at 85% of the lower of the fair market value of the Company’s common stock as of the first or the last day of each offering period. Employees are limited to contributing 15% of the employee’s eligible compensation and may not purchase more than $25,000 of stock during any calendar year or more than 2,000 shares during any one purchase period or a lesser amount determined by the board of directors. The 2016 ESPP will terminate ten years from the first purchase date under the plan, unless terminated earlier by the board of directors. As of December 31, 2018, the reserve remaining and available for future issuance under the 2016 ESPP was 50,851 shares. In June 2018, the 2016 ESPP was amended to provide for an automatic annual increase in the number of shares reserved for issuance thereunder on January 1 of each year for the remaining term of the year equal to (a) 1.0% of the number of issued and outstanding shares of common stock on December 31 of the immediately preceding year, or (b) a lesser amount as approved by the board of directors each year. As a result of the operation of this provision, on January 1, 2019, an additional 241,400 shares became available for issuance under the 2016 ESPP. The following table summarizes employee and non-employee stock option activity for the year ended December 31, 2018: Shares Issuable Under Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in Outstanding as of December 31, 2017 2,361,360 $ 5.21 8.72 $ 2,482 Granted 1,668,800 8.03 Exercised (521,665 ) 5.42 Forfeited (365,808 ) 5.20 Outstanding as of December 31, 2018 3,142,687 $ 6.67 8.52 $ 4,798 Options vested and expected to vest as of December 31, 2018 2,939,785 $ 6.49 8.45 $ 4,786 Options exercisable as of December 31, 2018 1,160,819 $ 5.85 7.68 $ 2,470 The aggregate intrinsic value of options outstanding, exercisable, vested and expected to vest were calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock as of the reporting date. For the years ended December 31, 2018, 2017, and 2016, the weighted-average grant date fair value of options granted was $8.03, $5.22, and $7.04, respectively. The total intrinsic value of options exercised during the years ended December 31, 2018 and 2017 was $1.9 million and $0.3 million, respectively. There were no option exercises during the year ended December 31, 2016. There were no stock options issued to non-employees during the years ended December 31, 2018, 2017, and 2016. For the year ended December 31, 2018, 6,626 non-employee stock options vested in the period. For the years ended December 31, 2017 and 2016, no non-employee stock options vested in the period. Restricted Common Stock The Company issued 253,232 restricted stock awards (“RSAs”) during the year ended December 31, 2015 with time-based and performance-based vesting conditions. Unvested shares of restricted common stock may not be sold or transferred by the holder. These restrictions lapse according to the time-based vesting conditions of each award. The following table summarizes employee and non-employee restricted stock activity for the year ended December 31, 2018: Shares Weighted Average Grant Date Fair Value Unvested restricted common stock as of December 31, 2017 33,307 $ 1.84 Granted — — Vested (26,444 ) 1.87 Forfeited — — Unvested restricted common stock as of December 31, 2018 6,863 $ 1.73 The fair value of RSAs that vested during the years ended December 31, 2018, 2017, and 2016 was $0.2 million, $0.2 million, and $0.3 million, respectively. There were no RSAs granted to non-employees during the years ended December 31, 2018, 2017, and 2016. For the year ended December 31, 2018, 21,645 non-employee RSAs vested in the period. For the years ended December 31, 2017 and 2016, no non-employee RSAs vested in the period. Stock-Based Compensation Expense Total stock-based compensation expense recognized from the Company’s equity incentive plans, 2018 Plan, and the 2016 ESPP for the years ended December 31, 2018, 2017, and 2016 was as follows (in thousands): Year Ended December 31, 2018 2017 2016 Employees Non-Employees Employees Non-Employees Employees Non-Employees Research and development $ 1,440 $ 234 $ 961 $ — $ 389 $ — General and administrative 2,606 — 1,531 — 832 — Total stock-based compensation expense $ 4,046 $ 234 $ 2,492 $ — $ 1,221 $ — No related tax benefits were recognized for the years ended December 31, 2018, 2017, and 2016 (see Note 11). The employee and non-employee awards contain both performance and service-based vesting conditions. No expense was recognized for the unvested employee and non-employee awards with only a performance condition for the years ended December 31, 2018, 2017, and 2016. The performance-based vesting conditions represent specific performance targets. Compensation expense for employee and non-employee share-based payment awards with performance conditions is recognized when the performance condition is deemed probable. In November 2018, the Company’s board of directors approved the acceleration of vesting and an extension in the exercise period for all outstanding equity awards held by one director upon his resignation (see Note 14). The result was a modification of 86,252 outstanding stock options and 43,290 restricted stock awards. The incremental fair value of $0.3 million, in connection with the modification of the awards, was recognized as stock compensation expense upon resignation with no future service or performance conditions required. As of December 31, 2018, the Company had an aggregate of $8.6 million of unrecognized stock-based compensation expense for options outstanding, which is expected to be recognized over a weighted average period of 2.7 years. There was no unrecognized stock-based compensation expense for RSAs outstanding as of December 31, 2018. In determining the fair value of the stock-based awards, the Company uses the Black-Scholes option-pricing model and assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment to determine. Expected Term The Company’s expected term represents the period that the Company’s stock-based awards are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term). The Company utilizes this method due to lack of historical exercise data and the plain-vanilla nature of the Company’s stock-based awards. Expected Volatility Since the Company was privately held through April 2016, it alone does not have the relevant company-specific historical data to support its expected volatility. As such, the Company has used an average of expected volatilities based on the volatilities of a representative group of publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants. Subsequent to the IPO, the Company began to consider the Company’s own historic volatility. However, due to its limited history as a public company, the Company still uses peer company data to assist in this analysis. For purposes of identifying comparable companies, the Company selected companies with comparable characteristics to it, including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. The Company intends to consistently apply this process using the same or similar comparable entities until a sufficient amount of historical information regarding the volatility of the Company’s own share price becomes available. Risk-Free Interest Rate The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of option. Expected Dividend The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. The fair value of the stock options granted under the 2018 Plan, 2016 Plan, and 2015 Plan and the shares available for purchase under the 2016 ESPP were determined using the Black-Scholes option-pricing model. The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards: Year Ended December 31, 2018 2017 2016 2018 Plan, 2016 Plan, and 2015 Plan Expected term (in years) 5.20 5.88 5.99 Expected volatility 74 % 86 % 87 % Risk-free interest 2.42 % 2.00 % 1.28 % Dividend yield 0 % 0 % 0 % 2016 ESPP Expected term (in years) 0.50 0.50 0.45 Expected volatility 66 % 78 % 82 % Risk-free interest 2.20 % 1.06 % 0.50 % Dividend yield 0 % 0 % 0 % |
Defined Contribution Plan
Defined Contribution Plan | 12 Months Ended |
Dec. 31, 2018 | |
Compensation And Retirement Disclosure [Abstract] | |
Defined Contribution Plan | 10. Defined Contribution Plan In September 2016, the Company began to sponsor a 401(k) retirement plan in which substantially all of its full-time employees are eligible to participate. Participants may contribute a percentage of their annual compensation to this plan, subject to statutory limitations. During the years ended December 31, 2018, 2017, 2016, the Company provided $0.2 million, $0.1 million, and $0.1 million, respectively, in contributions to the plan. |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2018 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 11. Income Taxes For the years ended December 31, 2018, 2017, and 2016, the Company recognized no provision or benefit from income taxes. The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows (in thousands): Year Ended December 31, 2018 2017 2016 Tax provision derived by applying the federal statutory rate to income before income taxes $ (9,313 ) $ (9,260 ) $ (7,377 ) Permanent differences and other 264 296 333 Federal tax credits (1,211 ) (1,294 ) (1,921 ) State tax credits 464 (284 ) (404 ) Change in tax rate — 7,869 — Change in the valuation allowance 9,796 2,673 9,369 Income tax expense /(benefit) $ — $ — $ — The components of the deferred tax assets and liabilities consist of the following (in thousands): December 31, 2018 2017 Deferred tax assets Net operating loss carryforward $ 20,276 $ 12,170 Intangible assets 38 29 Accrued expense 508 333 Stock-based compensation 682 386 Federal tax credits 7,260 5,572 State tax credits 359 824 Other 73 75 Total deferred tax assets 29,196 19,389 Deferred tax liabilities Depreciable assets $ (74 ) $ (63 ) Total deferred tax liabilities (74 ) (63 ) Less: Valuation allowance (29,122 ) (19,326 ) Deferred tax assets, net $ — $ — On December 22, 2017, the 2017 Tax Act was signed into law making significant changes to the Internal Revenue Code. The legislation significantly changes U.S. tax law by, among other things, lowering corporate income tax rates from a maximum of 35% to a flat 21% rate and reducing the orphan drug credit from 50% to 25% of qualifying expenditures, effective for tax years beginning after December 31, 2017. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. As a result of the reduction in the U.S. corporate income tax rate under the 2017 Tax Act, the Company revalued its deferred tax assets and liabilities as of December 31, 2017 resulting in a $7.9 million decrease in net deferred assets, with a corresponding reduction in the valuation allowance. The accounting for the income tax effects of the 2017 Tax Act and related adjustments were completed and included in the financial statements as of and for the year ended December 31, 2017. There were no income tax effects from the 2017 Tax Act for the year ended December 31, 2018. The Company has established a valuation allowance equal to the net deferred tax assets due to uncertainties regarding the realization of the deferred tax asset based on the Company’s lack of earnings history. The valuation allowance increased by $9.8 million, $2.7 million, and $9.4 million during the years ended December 31, 2018, 2017, and 2016, respectively, primarily due to continuing loss from operations. As of December 31, 2018 and 2017, the Company had U.S. net operating loss carryforwards (“NOL”) of $96.6 million and $58.0 million, respectively. As of December 31, 2018 and 2017, the Company had U.S. tax credit carryforwards of $7.3 million and $5.6 million, respectively, and state tax credit carryforwards of $0.4 million and $1.0 million, respectively. The net operating loss and tax credit carryforwards will begin to expire in 2033, if not utilized. The net operating loss and credit carryforwards are subject to Internal Revenue Service adjustments until the statute closes on the year the net operating loss or tax credits are utilized. As part of the PATH Act of 2015, certain eligible companies have the ability to convert a portion of their research tax credits to offset payroll tax liabilities. During the year ended December 31, 2017, the Company converted $0.5 million of its research tax credit to offset payroll tax liabilities. The Company did not convert any research tax credits to offset payroll tax liabilities during the years ended December 31, 2018 and 2016. As of December 31, 2018 and 2017, the Company held a payroll tax credit receivable of $0.3 million and $0.4 million, respectively, in prepaid expenses and other current assets and $0.0 million and $0.1 million, respectively, in other non-current assets. The Company has not completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company’s formation due to the complexity and cost associated with such a study, and the fact that there may be additional such ownership changes in the future. If the Company has experienced an ownership change at any time since its formation, utilization of the NOL or R&D credit carryforwards would be subject to an annual limitation under Section 382 or 383 of the Internal Revenue Code, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term, tax-exempt rate, and then could be subject to additional adjustments, as required. Additionally, the separate return limitation year (“SRLY”) rules may apply to losses of the Company’s seven wholly-owned subsidiary corporations. The SRLY rules limit the consolidated group’s use of a subsidiary corporation’s net operating losses to the amount of income generated by the subsidiary corporation after it becomes a member of the group. Any limitation may result in expiration of a portion of the NOL or R&D credit carryforwards before utilization. Further, until a study is completed and any limitation known, no amounts are being considered as an uncertain tax position or disclosed as an unrecognized tax benefit. Additionally, the Company does not expect any unrecognized tax benefits to change significantly over the next twelve months. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact its effective tax rate. Any carryforwards that will expire prior to utilization as a result of such limitations will be removed from deferred tax assets with a corresponding reduction of the valuation allowance. The Company files income tax returns in the U.S. and state jurisdictions. The Company is subject to examination by taxing authorities in its significant jurisdictions for the 2015 and subsequent years. However, due to NOL and tax attribute carryovers, the taxing authorities have the ability to adjust the NOLs and other tax attributes related to closed years. As of December 31, 2018 and 2017, there were no amounts recorded for uncertain tax positions. |
Net Loss Per Share
Net Loss Per Share | 12 Months Ended |
Dec. 31, 2018 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 12. Net Loss Per Share The Company computed net loss attributable per common stockholder using the two-class method required for participating securities through the date of the IPO. Immediately prior to the closing of the IPO, all outstanding convertible preferred stock was converted into common stock (see Note 7). The Company considered convertible preferred stock to be participating securities. In the event that the Company had paid out distributions, holders of convertible preferred stock would have participated in the distribution. The two-class method is an earnings (loss) allocation method under which earnings (loss) per share is calculated for common stock and participating security considering a participating security’s rights to undistributed earnings (loss) as if all such earnings (loss) had been distributed during the period. The convertible preferred stock did not have an obligation to fund losses and are therefore excluded from the calculation of basic net loss per share. Basic and diluted net loss per share is computed by dividing net loss by the weighted-average number of that class of common stock outstanding during the period. For periods in which the Company generated a net loss, the Company does not include the potential impact of dilutive securities in diluted net loss per share, as the impact of these items is anti-dilutive. The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented: Year Ended December 31, 2018 2017 2016 Series A convertible preferred stock — — 611,392 Series B convertible preferred stock — — 1,407,097 Unvested restricted common stock 26,841 57,629 100,634 Options to purchase common stock 3,014,984 2,043,420 1,063,778 |
Research and License Agreements
Research and License Agreements | 12 Months Ended |
Dec. 31, 2018 | |
Licensing Agreements [Abstract] | |
Research and License Agreements | 13. Research and License Agreements License Agreements In December 2013, two of the Company’s wholly owned subsidiaries, AECase, Inc. (“AECase”) and AEMase, Inc. (“AEMase”), entered into license agreements with the University of Texas at Austin (the “University”) under which the University granted to AECase and AEMase exclusive, worldwide, sublicenseable licenses. The University granted the AECase license under a patent application relating to the right to use technology related to the Company’s AEB3103 product candidate. The University granted the AEMase license under a patent relating to the right to use technology related to the Company’s AEB2109 product candidate. In January 2017, the Company entered into an Amended and Restated Patent License Agreement (the “Restated License”) with the University which consolidated the two license agreements, revised certain obligations, and licensed additional patent applications and invention disclosures to the Company. For the years ended December 31, 2018, 2017 and 2016, the Company paid $50,000, $30,000 and $10,000, respectively, in annual license fees. In connection with the above license agreements, the Company also entered into a Sponsored Research Agreement (the “SRA”) with the University in December 2013, which was subsequently amended. Under the terms of this research agreement, the Company engaged the University to perform certain nonclinical research activities related to the systemic depletion of amino acids for cancer and rare genetic disease therapy. The SRA expired on August 31, 2018. For the years ended December 31, 2018, 2017, and 2016, the Company paid $0.2 million, $0.6 million, and $0.8 million, respectively, to the University under the SRA. |
Related Party Transactions
Related Party Transactions | 12 Months Ended |
Dec. 31, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | 14. Related Party Transactions One of the founders (“Founder”), a non-employee member of the Company’s board of directors, entered into a consulting agreement with the Company in 2014 under which the Founder would receive $50,000 per year for a fixed number of hours of consulting and advisory services and receive equity incentive shares, which converted into 43,290 restricted stock awards and 13,852 stock options upon the LLC Conversion, with the vesting contingent on time and performance milestones being achieved. Effective November 7, 2018, the Founder resigned from his position as a member of the Company’s board of directors and is no longer deemed a related party. Upon resigning, the board of directors approved the immediate vesting of all unvested stock options and restricted stock. Additionally, the exercise period was extended from 90 days to 180 days. The acceleration of vesting and extension of the exercise period resulted in additional stock-based compensation expense (see Note 9). For the year ended December 31, 2018, there were no payments made to the Founder under the consulting agreement. In each of the years ended December 31, 2017 and 2016, the Company paid $50,000 to the Founder under the consulting agreement. As of December 31, 2018 and 2017, the Company had no outstanding liability to the related party. |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2018 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 15. Commitments and Contingencies The Company leases office and laboratory space in Austin, Texas under operating leases that commenced in January 2015 and February 2017, respectively. The office lease was amended in September 2016 to increase office space and extend the term to December 31, 2020. In addition, the amended office lease provides for tenant improvement allowances on both the original space and expansion space totaling $0.2 million. The Company signed a new laboratory lease agreement in October 2017 for the original laboratory space, which commenced on January 1, 2018. The laboratory lease was subsequently amended in October 2018 to increase the space and extend the lease term to September 30, 2021. As provided in the office and laboratory leases, monthly lease payments are subject to annual increases through the lease term. The Company recognizes rent expense on a straight-line basis over the non-cancellable term of each lease. The Company is subject to security deposit requirements Future annual minimum lease payments due under non-cancellable operating leases at December 31 of each year are as follows (in thousands): 2019 $ 397 2020 409 2021 83 Thereafter — Total minimum lease payments $ 889 For the years ended December 31, 2018, 2017, and 2016, the Company incurred $0.4 million, $0.4 million, and $0.2 million in rent expense under non-cancellable operating leases. |
Subsequent Events
Subsequent Events | 12 Months Ended |
Dec. 31, 2018 | |
Subsequent Events [Abstract] | |
Subsequent Events | 16. Subsequent Events In February 2019, the Company issued and sold 4,625,000 shares of common stock at a public offering price of $8.00 per share and pre-funded warrants to purchase 4,000,000 shares of common stock at a public offering price of $7.9999 per warrant in an underwritten public offering pursuant to a shelf registration statement on Form S-3. This includes the full exercise by the underwriters of their option to purchase up to 1,125,000 additional shares of common stock. The net proceeds to the Company from this public offering were approximately $64.5 million, after deducting underwriting discounts and commissions of $4.1 million and estimated offering costs of $0.4 million. |
Selected Quarterly Financial Da
Selected Quarterly Financial Data (Unaudited) | 12 Months Ended |
Dec. 31, 2018 | |
Selected Quarterly Financial Information [Abstract] | |
Selected Quarterly Financial Data (Unaudited) | 17. Selected Quarterly Financial Data (Unaudited) Selected quarterly results from operations for the years ended December 31, 2018 and 2017 are as follows (in thousands, except per share amounts): 2018 Quarter Ended March 31, June 30, September December Grant revenues $ 1,510 $ 2,378 $ — $ — Loss from operations (8,245 ) (9,670 ) (12,243 ) (15,305 ) Net loss (8,119 ) (9,414 ) (11,917 ) (14,898 ) Basic and diluted net loss per common share $ (0.49 ) $ (0.46 ) $ (0.54 ) $ (0.62 ) 2017 Quarter Ended March 31, June 30, September December Grant revenues $ 982 $ 1,479 $ 1,261 $ 1,483 Loss from operations (6,331 ) (6,720 ) (7,998 ) (6,627 ) Net loss (6,247 ) (6,632 ) (7,874 ) (6,483 ) Basic and diluted net loss per common share $ (0.47 ) $ (0.47 ) $ (0.48 ) $ (0.39 ) |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2018 | |
Accounting Policies [Abstract] | |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Such management estimates include those related to accruals of research and development related costs, fair values of preferred and common stock, stock-based compensation, and certain company income tax related items. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ significantly from those estimates. Prior to becoming a public company, the Company utilized significant estimates and assumptions in determining the fair value of its common stock. The board of directors determined the estimated fair value of common stock based on a number of objective and subjective factors, including external market conditions affecting the biotechnology industry sector, the price at which the Company sold shares of convertible preferred stock, the superior rights and preferences of securities senior to the Company’s common stock, and the marketability at the time. The Company utilized valuation methodologies in accordance with the American Institute of Certified Public Accountants Practice Guide, Audit and Accounting Practice Aid Series: Valuation of Privately-Held-Company Securities Issued as Compensation |
Cash and Cash Equivalents | Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist of money market funds and debt securities and are stated at fair value. |
Marketable Securities | Marketable Securities All investments have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase. The Company may or may not hold securities with stated maturities greater than one year until maturity. All available-for-sale securities are considered available to support current operations and are classified as current assets. Unrealized gains and losses are excluded from earnings and are reported as a component of accumulated comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in other income (expense). The cost of securities sold is based on the specific-identification method. There were no realized gains or losses on marketable securities for the years ended December 31, 2018, 2017, and 2016. Interest on marketable securities is included in interest income. |
Concentration of Credit Risk | Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, and marketable securities. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government, U.S. government-sponsored agencies and highly rated banks, subject to certain concentration limits and restrictions on maturities. The Company’s cash, cash equivalents, and marketable securities are held by financial institutions in the United States that management believes are of high credit quality. Amounts on deposit may at times exceed federally insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents and its accounts are monitored by management to mitigate risk. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents and bond issuers. |
Property and Equipment | Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance that do not extend the life or improve an asset are expensed as incurred. Upon retirement or sale, the cost of disposed assets and their related accumulated depreciation and amortization are removed from the balance sheet. Any gain or loss is credited or charged to operations. The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Furniture and office equipment 5 years Computer equipment 3 years Software 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life |
Impairment of Long-Lived Assets | Impairment of Long-Lived Assets Long-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable, and the carrying amount exceeds the projected discounted future cash flows arising from these assets. There were no impairments of long-lived assets for the years ended December 31, 2018, 2017, and 2016. |
Accrued Research And Development Costs | Accrued Research and Development Costs The Company records the costs associated with research nonclinical studies, clinical trials, and manufacturing development as incurred. These costs are a significant component of the Company’s research and development expenses, with a substantial portion of the Company’s on-going research and development activities conducted by third-party service providers, including contract research and manufacturing organizations. The Company accrues for expenses resulting from obligations under agreements with contract research organizations (“CROs”), contract manufacturing organizations (“CMOs”), and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs, and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through analysis with internal personnel and external service providers as to the progress or stage of completion of the services. The Company makes significant judgments and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO, or outside service provider, the payments will be recorded as a prepaid asset which will be amortized as the contracted services are performed. As actual costs become known, the Company adjusts its accruals. Inputs, such as the services performed, the number of patients enrolled, or the study duration, may vary from the Company’s estimates, resulting in adjustments to research and development expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. The Company has not experienced any material deviations between accrued and actual research and development expenses. |
Leases | Leases The Company entered into lease agreements for its office and laboratory facilities. The leases are classified as operating leases. The Company records rent expense on a straight-line basis over the term of the leases and, accordingly records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. Incentives granted under the Company’s facilities leases, including allowances to fund leasehold improvements, are deferred and are recognized as adjustments to rental expense on a straight-line basis over the term of the lease. |
Fair Value of Financial Instruments | Fair Value of Financial Instruments The Company uses fair value measurements to record fair value adjustments to certain financial and non-financial assets and liabilities and to determine fair value disclosures. The accounting standards define fair value, establish a framework for measuring fair value, and require disclosures about fair value measurements. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the principal or most advantageous market in which the Company would transact are considered along with assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The accounting standard for fair value establishes a fair value hierarchy based on three levels of inputs, the first two of which are considered observable and the last unobservable, that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels of inputs that may be used to measure fair value are as follows: Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3: Valuations based on unobservable inputs to the valuation methodology and including data about assumptions that market participants would use in pricing the asset or liability based on the best information available under the circumstances. Financial instruments carried at fair value include cash, cash equivalents, and marketable securities. The carrying amount of accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. |
Revenue Recognition | Revenue Recognition The Company’s sole source of revenue was grant revenue related to a $19.8 million research grant received from the Cancer Prevention and Research Institute of Texas (“CPRIT”), covering a four-year period from June 1, 2014 through May 31, 2018. Grant revenue was recognized when qualifying costs were incurred and there was reasonable assurance that the conditions of the award had been met for collection. Proceeds received prior to the costs being incurred or the conditions of the award being met were recognized as deferred revenue until the services were performed and the conditions of the award were met (see Note 8). |
Research and Development Costs | Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include, but are not limited to, salaries, benefits, travel, stock-based compensation, consulting costs, contract research service costs, laboratory supplies and facilities, contract manufacturing costs, and costs paid to other third parties that conduct research and development activities on the Company’s behalf. Amounts incurred in connection with license agreements are also included in research and development expense. Certain research and development costs incurred were settled contractually by the Company issuing a variable number of the Company’s shares determined by dividing the fixed monetary amount of costs incurred by the issuance-date fair value of the issuable shares. The Company recorded research and development expense for these costs and accrued for the fixed monetary amount as an accrued liability as the services were rendered until the amount was settled. The remaining Company obligation to settle these costs with Company shares was converted to a cash-based payment through a contract amendment with the service provider. Advance payments for goods or services to be rendered in the future for use in research and development activities are recorded as a prepaid asset and expensed as the related goods are delivered or the services are performed. |
Stock-Based Compensation | Stock-Based Compensation The Company recognizes the cost of stock-based awards granted to employees based on the estimated grant-date fair values of the awards. The value of the award is recognized as compensation expense on a straight-line basis over the requisite service period. Forfeitures are recognized when they occur, which may result in the reversal of compensation costs in subsequent periods as the forfeitures arise. The Company elected to early adopt ASU 2018-07, Compensation – Stock Compensation (Topic 718) effective January 1, 2018. All non-employee share-based payment awards granted prior to adoption were remeasured at fair value as of the adoption date. There was no material impact on the Company’s consolidated financial statements from the adoption. All non-employee share-based payment awards granted after adoption are measured at grant-date fair value. Compensation expense for employee and non-employee share-based payment awards with performance conditions is recognized when the performance condition is deemed probable. |
Income Taxes | Income Taxes The Company and its seven wholly-owned subsidiary corporations use the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Additionally, any changes in income tax laws are immediately recognized in the year of enactment. A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense. |
Comprehensive Loss | Comprehensive Loss Comprehensive loss is the change in stockholders’ equity from transactions and other events and circumstances other than those resulting from investments by stockholders and distributions to stockholders. The Company’s other comprehensive income (loss) is currently comprised of changes in unrealized gains and losses on available-for-sale securities. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which establishes a comprehensive new lease accounting model. The new standard: (a) clarifies the definition of a lease; (b) requires a dual approach to lease classification similar to current lease classifications; and, (c) causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use (ROU) asset. The new standard is effective for fiscal years and interim periods beginning after December 15, 2018, with early adoption permitted. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which provides entities with an additional transition method. Under ASU 2018-11, entities have the option of initially applying Topic 842 at the adoption date, rather than at the beginning of the earliest comparative period presented, and recognizing the cumulative effect of applying the new standard as an adjustment to beginning retained earnings in the year of adoption while continuing to present all prior periods under previous lease accounting guidance. The Company elected this transition method with an adoption date of January 1, 2019. The new standard provides a number of optional practical expedients in transition. The Company plans to elect all of the available practical expedients. The Company expects that the most significant effects of adopting this standard will primarily relate to (a) the recognition of ROU assets and lease liabilities on the balance sheet in relation to its existing operating lease agreements for the office and laboratory spaces in Austin, Texas; and (b) providing significant new disclosures about leasing activities. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40) |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Accounting Policies [Abstract] | |
Schedule Of Estimated Useful Lives Of Property Plant And Equipment | The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Furniture and office equipment 5 years Computer equipment 3 years Software 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life |
Fair Value Measurement (Tables)
Fair Value Measurement (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): December 31, 2018 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 7,180 $ — $ — $ 7,180 Reverse repurchase agreements — 6,250 — 6,250 Commercial paper — 53,916 — 53,916 U.S. government securities — 4,112 — 4,112 Total financial assets $ 7,180 $ 64,278 $ — $ 71,458 December 31, 2017 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 1,674 $ — $ — $ 1,674 Reverse repurchase agreements — 7,250 — 7,250 U.S. treasury securities 1,501 — — 1,501 U.S. government securities — 35,981 — 35,981 Total financial assets $ 3,175 $ 43,231 $ — $ 46,406 |
Cash Equivalents and Marketab_2
Cash Equivalents and Marketable Securities (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Investments Debt And Equity Securities [Abstract] | |
Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities | The following tables summarize the estimated fair value of the Company’s cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands): December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 7,180 $ — $ — $ 7,180 Reverse repurchase agreements 6,250 — — 6,250 Commercial paper 5,977 — (1 ) 5,976 Total cash equivalents 19,407 — (1 ) 19,406 Marketable securities: Commercial paper 47,964 — (24 ) 47,940 U.S. government securities 4,114 — (2 ) 4,112 Total marketable securities $ 52,078 $ — $ (26 ) $ 52,052 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 1,674 $ — $ — $ 1,674 Reverse repurchase agreements 7,250 — — 7,250 Total cash equivalents 8,924 — — 8,924 Marketable securities: U.S. treasury securities 1,502 — (1 ) 1,501 U.S. government securities 36,082 — (101 ) 35,981 Total marketable securities $ 37,584 $ — $ (102 ) $ 37,482 |
Summary of Contractual Maturities of Marketable Securities at Estimated Fair Value | The following table summarizes the contractual maturities of the Company's marketable securities at estimated fair value (in thousands): December 31, 2018 2017 Due in one year or less $ 52,052 $ 34,498 Due in 1 - 2 years — 2,984 Total marketable securities $ 52,052 $ 37,482 |
Property and Equipment, Net (Ta
Property and Equipment, Net (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Property Plant And Equipment [Abstract] | |
Schedule of Property and Equipment Net | Property and equipment, net consist of the following (in thousands): December 31, 2018 2017 Laboratory equipment $ 981 $ 651 Furniture and office equipment 227 209 Computer equipment 89 111 Software 99 99 Leasehold improvements 374 271 Property and equipment, gross 1,770 1,341 Less: Accumulated depreciation and amortization (752 ) (487 ) Property and equipment, net $ 1,018 $ 854 |
Accrued and Other Current Lia_2
Accrued and Other Current Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Accrued Liabilities And Other Liabilities [Abstract] | |
Accrued and Other Current Liabilities | Accrued and other current liabilities consist of the following (in thousands): December 31, 2018 2017 Accrued compensation $ 2,643 $ 1,837 Accrued contracted research and development costs 5,993 2,552 Accrued professional and consulting fees 807 672 Accrued and other current liabilities 133 159 Total accrued and other current liabilities $ 9,576 $ 5,220 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Employee and Non-Employee Stock Option Activity | The following table summarizes employee and non-employee stock option activity for the year ended December 31, 2018: Shares Issuable Under Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in Outstanding as of December 31, 2017 2,361,360 $ 5.21 8.72 $ 2,482 Granted 1,668,800 8.03 Exercised (521,665 ) 5.42 Forfeited (365,808 ) 5.20 Outstanding as of December 31, 2018 3,142,687 $ 6.67 8.52 $ 4,798 Options vested and expected to vest as of December 31, 2018 2,939,785 $ 6.49 8.45 $ 4,786 Options exercisable as of December 31, 2018 1,160,819 $ 5.85 7.68 $ 2,470 |
Summary of Employee and Non-Employee Restricted Stock Activity | The following table summarizes employee and non-employee restricted stock activity for the year ended December 31, 2018: Shares Weighted Average Grant Date Fair Value Unvested restricted common stock as of December 31, 2017 33,307 $ 1.84 Granted — — Vested (26,444 ) 1.87 Forfeited — — Unvested restricted common stock as of December 31, 2018 6,863 $ 1.73 |
Summary of Stock-Based Compensation Expense | Total stock-based compensation expense recognized from the Company’s equity incentive plans, 2018 Plan, and the 2016 ESPP for the years ended December 31, 2018, 2017, and 2016 was as follows (in thousands): Year Ended December 31, 2018 2017 2016 Employees Non-Employees Employees Non-Employees Employees Non-Employees Research and development $ 1,440 $ 234 $ 961 $ — $ 389 $ — General and administrative 2,606 — 1,531 — 832 — Total stock-based compensation expense $ 4,046 $ 234 $ 2,492 $ — $ 1,221 $ — |
Summary of Weighted-Average Assumptions Used in Calculating Fair Value of Awards | The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards: Year Ended December 31, 2018 2017 2016 2018 Plan, 2016 Plan, and 2015 Plan Expected term (in years) 5.20 5.88 5.99 Expected volatility 74 % 86 % 87 % Risk-free interest 2.42 % 2.00 % 1.28 % Dividend yield 0 % 0 % 0 % 2016 ESPP Expected term (in years) 0.50 0.50 0.45 Expected volatility 66 % 78 % 82 % Risk-free interest 2.20 % 1.06 % 0.50 % Dividend yield 0 % 0 % 0 % |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Income Tax Disclosure [Abstract] | |
Summary of Difference Between Provision for Income Taxes and Amounts Computed by Applying Statutory Federal Income Tax Rate to Income Before Income Taxes | The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows (in thousands): Year Ended December 31, 2018 2017 2016 Tax provision derived by applying the federal statutory rate to income before income taxes $ (9,313 ) $ (9,260 ) $ (7,377 ) Permanent differences and other 264 296 333 Federal tax credits (1,211 ) (1,294 ) (1,921 ) State tax credits 464 (284 ) (404 ) Change in tax rate — 7,869 — Change in the valuation allowance 9,796 2,673 9,369 Income tax expense /(benefit) $ — $ — $ — |
Components of Deferred Tax Assets and Liabilities | The components of the deferred tax assets and liabilities consist of the following (in thousands): December 31, 2018 2017 Deferred tax assets Net operating loss carryforward $ 20,276 $ 12,170 Intangible assets 38 29 Accrued expense 508 333 Stock-based compensation 682 386 Federal tax credits 7,260 5,572 State tax credits 359 824 Other 73 75 Total deferred tax assets 29,196 19,389 Deferred tax liabilities Depreciable assets $ (74 ) $ (63 ) Total deferred tax liabilities (74 ) (63 ) Less: Valuation allowance (29,122 ) (19,326 ) Deferred tax assets, net $ — $ — |
Net Loss Per Share (Tables)
Net Loss Per Share (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Earnings Per Share [Abstract] | |
Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share | The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented: Year Ended December 31, 2018 2017 2016 Series A convertible preferred stock — — 611,392 Series B convertible preferred stock — — 1,407,097 Unvested restricted common stock 26,841 57,629 100,634 Options to purchase common stock 3,014,984 2,043,420 1,063,778 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Commitments And Contingencies Disclosure [Abstract] | |
Summary of Future Annual Minimum Lease Payments Due Under Non-cancellable Operating Leases | Future annual minimum lease payments due under non-cancellable operating leases at December 31 of each year are as follows (in thousands): 2019 $ 397 2020 409 2021 83 Thereafter — Total minimum lease payments $ 889 |
Selected Quarterly Financial _2
Selected Quarterly Financial Data (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Selected Quarterly Financial Information [Abstract] | |
Schedule of Selected Quarterly Results from Operations | Selected quarterly results from operations for the years ended December 31, 2018 and 2017 are as follows (in thousands, except per share amounts): 2018 Quarter Ended March 31, June 30, September December Grant revenues $ 1,510 $ 2,378 $ — $ — Loss from operations (8,245 ) (9,670 ) (12,243 ) (15,305 ) Net loss (8,119 ) (9,414 ) (11,917 ) (14,898 ) Basic and diluted net loss per common share $ (0.49 ) $ (0.46 ) $ (0.54 ) $ (0.62 ) 2017 Quarter Ended March 31, June 30, September December Grant revenues $ 982 $ 1,479 $ 1,261 $ 1,483 Loss from operations (6,331 ) (6,720 ) (7,998 ) (6,627 ) Net loss (6,247 ) (6,632 ) (7,874 ) (6,483 ) Basic and diluted net loss per common share $ (0.47 ) $ (0.47 ) $ (0.48 ) $ (0.39 ) |
The Company and Basis of Pres_2
The Company and Basis of Presentation - Additional Information (Details) $ in Thousands | 12 Months Ended | |
Dec. 31, 2018USD ($)Segment | Dec. 31, 2017USD ($) | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | ||
Number of operating segments | Segment | 1 | |
Working capital | $ 66,400 | |
Accumulated deficit | (116,861) | $ (72,513) |
Cash, cash equivalents and marketable securities | $ 74,500 |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies - Additional Information (Details) | Jun. 01, 2014USD ($) | Dec. 31, 2018USD ($)Subsidary | Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) |
Summary Of Significant Accounting Policies [Line Items] | ||||
Marketable Securities, Realized Gain (Loss) | $ 0 | $ 0 | $ 0 | |
Impairments of long-lived assets | $ 0 | $ 0 | $ 0 | |
Number of subsidiary corporations owned | Subsidary | 7 | |||
Maximum | ||||
Summary Of Significant Accounting Policies [Line Items] | ||||
Marketable securities stated maturity period | 1 year | |||
Maximum | CPRIT | ||||
Summary Of Significant Accounting Policies [Line Items] | ||||
Research grant contract amount | $ 19,800,000 |
Summary of Significant Accoun_5
Summary of Significant Accounting Policies - Summary of Useful Lives of Property and Equipment (Details) | 12 Months Ended |
Dec. 31, 2018 | |
Laboratory Equipment | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 5 years |
Furniture and Office Equipment | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 5 years |
Computer Equipment | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 3 years |
Software | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 3 years |
Leasehold Improvements | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | Shorter of remaining lease term or estimated useful life |
Fair Value Measurements - Finan
Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Financial Assets | ||
Financial assets, fair value | $ 71,458 | $ 46,406 |
U.S. treasury securities | ||
Financial Assets | ||
Financial assets, fair value | 1,501 | |
Commercial paper | ||
Financial Assets | ||
Financial assets, fair value | 53,916 | |
Money market funds | ||
Financial Assets | ||
Financial assets, fair value | 7,180 | 1,674 |
Reverse repurchase agreements | ||
Financial Assets | ||
Financial assets, fair value | 6,250 | 7,250 |
U.S. government securities | ||
Financial Assets | ||
Financial assets, fair value | 4,112 | 35,981 |
Level 1 | ||
Financial Assets | ||
Financial assets, fair value | 7,180 | 3,175 |
Level 1 | U.S. treasury securities | ||
Financial Assets | ||
Financial assets, fair value | 1,501 | |
Level 1 | Money market funds | ||
Financial Assets | ||
Financial assets, fair value | 7,180 | 1,674 |
Level 2 | ||
Financial Assets | ||
Financial assets, fair value | 64,278 | 43,231 |
Level 2 | Commercial paper | ||
Financial Assets | ||
Financial assets, fair value | 53,916 | |
Level 2 | Reverse repurchase agreements | ||
Financial Assets | ||
Financial assets, fair value | 6,250 | 7,250 |
Level 2 | U.S. government securities | ||
Financial Assets | ||
Financial assets, fair value | $ 4,112 | $ 35,981 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Details) | 12 Months Ended |
Dec. 31, 2018USD ($) | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value assets transferred from level 1 to level 2 | $ 0 |
Minimum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value inputs, probabilities of going public by term | 6 months 18 days |
Maximum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value inputs, probabilities of going public by term | 1 month 17 days |
Probabilities of going public, percentage | Minimum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.125 |
Probabilities of going public, percentage | Maximum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.80 |
Discount rate | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.30 |
Discount for lack of marketability | Minimum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.30 |
Discount for lack of marketability | Maximum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.075 |
Expected term | Minimum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement term | 2 years 9 months 18 days |
Expected term | Maximum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement term | 3 years |
Risk free interest rate | Minimum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.008 |
Risk free interest rate | Maximum | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.011 |
Expected volatility rate | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Fair value input, Equity securities measurement | 0.70 |
Cash Equivalents and Marketab_3
Cash Equivalents and Marketable Securities - Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | $ 19,407 | $ 8,924 |
Cash equivalents, gross unrealized losses | (1) | |
Cash equivalents, estimated fair value | 19,406 | 8,924 |
Marketable securities, amortized cost | 52,078 | 37,584 |
Marketable securities, gross unrealized losses | (26) | (102) |
Marketable securities, estimated fair value | 52,052 | 37,482 |
Money market funds | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 7,180 | 1,674 |
Cash equivalents, estimated fair value | 7,180 | 1,674 |
Reverse repurchase agreements | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 6,250 | 7,250 |
Cash equivalents, estimated fair value | 6,250 | 7,250 |
Commercial paper | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 5,977 | |
Cash equivalents, gross unrealized losses | (1) | |
Cash equivalents, estimated fair value | 5,976 | |
Marketable securities, amortized cost | 47,964 | |
Marketable securities, gross unrealized losses | (24) | |
Marketable securities, estimated fair value | 47,940 | |
U.S. treasury securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Marketable securities, amortized cost | 1,502 | |
Marketable securities, gross unrealized losses | (1) | |
Marketable securities, estimated fair value | 1,501 | |
U.S. government securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Marketable securities, amortized cost | 4,114 | 36,082 |
Marketable securities, gross unrealized losses | (2) | (101) |
Marketable securities, estimated fair value | $ 4,112 | $ 35,981 |
Cash Equivalents and Marketab_4
Cash Equivalents and Marketable Securities - Additional Information (Details) - U.S. government and agency securities $ in Millions | Dec. 31, 2018USD ($)Security | Dec. 31, 2017USD ($)Security |
Cash Equivalents And Marketable Securities [Line Items] | ||
Fair value of debt securities in an unrealized loss position | $ | $ 45.6 | $ 37.5 |
Number of securities in a significant unrealized loss position | Security | 0 | 0 |
Cash Equivalents and Marketab_5
Cash Equivalents and Marketable Securities - Summary of Contractual Maturities of Marketable Securities at Estimated Fair Value (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Investments Debt And Equity Securities [Abstract] | ||
Due in one year or less | $ 52,052 | $ 34,498 |
Due in 1 - 2 years | 2,984 | |
Total marketable securities | $ 52,052 | $ 37,482 |
Property and Equipment, Net - S
Property and Equipment, Net - Schedule of Property and Equipment Net (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 1,770 | $ 1,341 |
Less: Accumulated depreciation and amortization | (752) | (487) |
Property and equipment, net | 1,018 | 854 |
Laboratory Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 981 | 651 |
Furniture and Office Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 227 | 209 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 89 | 111 |
Software | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 99 | 99 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 374 | $ 271 |
Property and Equipment, Net - A
Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Property Plant And Equipment [Abstract] | |||
Depreciation and amortization | $ 293 | $ 249 | $ 132 |
Accrued and Other Current Lia_3
Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Accrued Liabilities And Other Liabilities [Abstract] | ||
Accrued compensation | $ 2,643 | $ 1,837 |
Accrued contracted research and development costs | 5,993 | 2,552 |
Accrued professional and consulting fees | 807 | 672 |
Accrued and other current liabilities | 133 | 159 |
Total accrued and other current liabilities | $ 9,576 | $ 5,220 |
Convertible Preferred Stock a_2
Convertible Preferred Stock and Stockholders' Equity - Additional Information (Details) | Apr. 12, 2016USD ($)$ / sharesshares | Apr. 05, 2016USD ($)shares | Dec. 31, 2018USD ($)Vote$ / sharesshares | Oct. 31, 2018USD ($)$ / sharesshares | Apr. 30, 2018USD ($)$ / sharesshares | Jun. 30, 2017USD ($)$ / sharesshares | May 31, 2017USD ($) | Dec. 31, 2018USD ($)Vote$ / sharesshares | Dec. 31, 2017USD ($)$ / sharesshares | Dec. 31, 2016USD ($)shares | Dec. 31, 2015USD ($)shares |
Class Of Stock [Line Items] | |||||||||||
Preferred stock, shares outstanding | shares | 0 | 0 | 0 | ||||||||
Convertible preferred stock, terms of conversion | all of the outstanding convertible preferred stock was automatically converted into 7,172,496 shares of common stock on a one-to-one basis | ||||||||||
shares authorized | shares | 510,000,000 | ||||||||||
Common stock, shares authorized | shares | 500,000,000 | 500,000,000 | 500,000,000 | 500,000,000 | |||||||
Preferred stock, shares authorized | shares | 10,000,000 | 10,000,000 | 10,000,000 | 10,000,000 | |||||||
Common stock, par value | $ / shares | $ 0.0001 | $ 0.0001 | $ 0.0001 | $ 0.0001 | |||||||
Preferred stock, par value | $ / shares | $ 0.0001 | $ 0.0001 | $ 0.0001 | $ 0.0001 | |||||||
Number of common stock holders voting right | Vote | 1 | 1 | |||||||||
Common stock voting rights | Each holder of common stock is entitled to one vote for each share of common stock held | ||||||||||
Common stock dividends declared | $ 0 | ||||||||||
Proceeds from issuance of common stock in public offering, net | $ 54,048,000 | $ 11,380,000 | $ 47,266,000 | ||||||||
At-the-Market (ATM) Sales Agreement | JonesTrading Institutional Services LLC | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Number of shares issued | shares | 1,845,820 | ||||||||||
Public offering price | $ / shares | $ 9.21 | ||||||||||
Aggregate offering price of common stock | $ 20,000,000 | ||||||||||
Net proceeds from sale of common stock | $ 16,400,000 | ||||||||||
Proceeds from issuance of common stock gross | $ 17,000,000 | ||||||||||
At-the-Market (ATM) Sales Agreement | Jeffries LLC | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Aggregate offering price of common stock | $ 60,000,000 | ||||||||||
Common Stock | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Convertible preferred stock converted into common stock | shares | 7,172,496 | ||||||||||
Convertible preferred stock converted into common stock, carrying value | $ 58,300,000 | ||||||||||
Number of shares issued | shares | 5,046,510 | 6,893,000 | 3,000,000 | 5,482,000 | |||||||
Proceeds from issuance of common stock upon initial public offering, net | $ 47,300,000 | ||||||||||
Underwriting discounts and commissions | $ 2,400,000 | ||||||||||
Offering costs | $ 300,000 | ||||||||||
Public offering price | $ / shares | $ 8 | ||||||||||
Proceeds from issuance of common stock in public offering, net | $ 1,000 | ||||||||||
Common Stock | IPO | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Number of shares issued | shares | 5,481,940 | ||||||||||
Public offering price | $ / shares | $ 10 | ||||||||||
Underwriting discounts and commissions | $ 3,800,000 | ||||||||||
Offering costs | $ 3,700,000 | ||||||||||
Common Stock | Underwriters' Over-allotment Option | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Number of shares issued | shares | 481,940 | 546,510 | |||||||||
Common Stock | Follow-on Public Offering | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Proceeds from issuance of common stock in public offering, net | $ 37,700,000 | ||||||||||
Common Stock | Follow-on Public Offering | JonesTrading Institutional Services LLC | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Number of shares issued | shares | 3,000,000 | ||||||||||
Underwriting discounts and commissions | $ 600,000 | ||||||||||
Offering costs | $ 300,000 | ||||||||||
Public offering price | $ / shares | $ 4.10 | ||||||||||
Proceeds from issuance of common stock in public offering, net | $ 11,400,000 | ||||||||||
Series A Convertible Preferred Stock | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Preferred stock, shares outstanding | shares | 2,172,520 | ||||||||||
Preferred stock outstanding carrying value | $ 13,600,000 | ||||||||||
Series B Convertible Preferred Stock | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Preferred stock, shares outstanding | shares | 4,999,976 | ||||||||||
Preferred stock outstanding carrying value | $ 44,700,000 |
Grant Revenues - Additional Inf
Grant Revenues - Additional Information (Details) - USD ($) | Jun. 01, 2014 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | May 31, 2018 |
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||||||||||
Grant revenues | $ 0 | $ 0 | $ 2,378,000 | $ 1,510,000 | $ 1,483,000 | $ 1,261,000 | $ 1,479,000 | $ 982,000 | $ 3,888,000 | $ 5,205,000 | $ 4,628,000 | ||
Type of revenue [extensible list] | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | ||
Outstanding grant receivable | $ 3,078,000 | $ 3,078,000 | |||||||||||
Deferred revenue | $ 20,000 | $ 20,000 | |||||||||||
CPRIT | |||||||||||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||||||||||
Grant contract term | 4 years | ||||||||||||
Grant contract beginning date | Jun. 1, 2014 | ||||||||||||
Grant contract expiration date | May 31, 2018 | ||||||||||||
Grant revenues | $ 19,800,000 | ||||||||||||
Type of revenue [extensible list] | us-gaap:GrantMember | ||||||||||||
CPRIT | Maximum | |||||||||||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||||||||||
Research grant contract amount | $ 19,800,000 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Details) - USD ($) | 1 Months Ended | 12 Months Ended | |||||||||||
Nov. 30, 2018 | Oct. 31, 2018 | Jun. 30, 2018 | Feb. 28, 2018 | Apr. 30, 2016 | Mar. 31, 2015 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Jan. 01, 2019 | Jan. 01, 2018 | Jan. 01, 2017 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Outstanding option awards | 3,142,687 | 2,361,360 | |||||||||||
Stock option exercised | 521,665 | ||||||||||||
Tax benefits recognized | $ 0 | $ 0 | $ 0 | ||||||||||
Expected dividend yield | 0.00% | ||||||||||||
RSAs | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Number of vesting fair value | $ 200,000 | $ 200,000 | $ 300,000 | ||||||||||
Unrecognized stock-based compensation expense for RSAs | $ 0 | ||||||||||||
Non-Employees | RSAs | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Number of grant to non-employees | 0 | 0 | 0 | ||||||||||
Number of vested shares | 21,645 | 0 | 0 | ||||||||||
Employees and Non-Employees | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Expense recognized for unvested employee and non-employee awards | $ 0 | $ 0 | $ 0 | ||||||||||
Employees and Non-Employees | RSAs | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Number of stock issued | 253,232 | ||||||||||||
Director | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Incremental fair value of outstanding equity awards | $ 300,000 | ||||||||||||
Director | RSAs | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Modification of outstanding award | 43,290 | ||||||||||||
Director | Stock Options | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Modification of outstanding award | 86,252 | ||||||||||||
Stock Options | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Weighted-average grant date fair value | $ 8.03 | $ 5.22 | $ 7.04 | ||||||||||
Stock option exercised | 0 | ||||||||||||
Intrinsic value of options exercised | $ 1,900,000 | $ 300,000 | |||||||||||
Unrecognized stock-based compensation expense for options | $ 8,600,000 | ||||||||||||
Weighted average period over which unrecognized compensation is expected to be recognized | 2 years 8 months 12 days | ||||||||||||
Stock Options | Non-Employees | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Stock option issued | 0 | 0 | 0 | ||||||||||
Stock option vested | 6,626 | 0 | 0 | ||||||||||
2015 Equity Incentive Plan | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Awards granted, expiration period | 10 years | ||||||||||||
Combined voting power of all classes of stock | 10.00% | ||||||||||||
Option vesting, year | 5 years | ||||||||||||
Number of common stock to option outstanding | 268,716 | ||||||||||||
Number of common stock available for issuance | 509,869 | ||||||||||||
2015 Equity Incentive Plan | Minimum | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Percentage of market value of common stock | 100.00% | ||||||||||||
2016 Equity Incentive Plan | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Initial reserves of common stock | 1,100,000 | ||||||||||||
Increase in number of shares of common stock reserved for issuance | 1,759,602 | ||||||||||||
Share based compensation plan expiration date | Aug. 7, 2028 | ||||||||||||
Percentage of outstanding share of common stock | 4.00% | ||||||||||||
Additional number of shares available for issuance | 666,807 | 537,233 | |||||||||||
Total number of common stock reserved for issuance | 4,750,902 | ||||||||||||
Outstanding option awards | 2,760,071 | ||||||||||||
2016 Equity Incentive Plan | Subsequent Event | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Additional number of shares available for issuance | 965,603 | ||||||||||||
2018 Equity Inducement Plan | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Initial reserves of common stock | 1,100,000 | ||||||||||||
Total number of common stock reserved for issuance | 1,100,000 | ||||||||||||
Outstanding option awards | 113,900 | ||||||||||||
2018 Plan, 2016 Plan and 2015 Plan | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Awards granted, expiration period | 10 years | ||||||||||||
2018 Plan, 2016 Plan and 2015 Plan | Four Year Vesting | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Option vesting, year | 4 years | ||||||||||||
2018 Plan, 2016 Plan and 2015 Plan | Maximum | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Option vesting, year | 4 years | ||||||||||||
2016 Employee Stock Purchase Plan | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Number of common stock available for issuance | 50,851 | ||||||||||||
Percentage of outstanding share of common stock | 1.00% | ||||||||||||
Total number of common stock reserved for issuance | 165,000 | ||||||||||||
Percentage of discount through payroll deductions to eligible employees to purchase common stock | 15.00% | ||||||||||||
Percentage of fair market value of common stock | 85.00% | ||||||||||||
Maximum number of shares permitted for per employee | 2,000 | ||||||||||||
Maximum purchase value per employee under employee stock purchase plan | $ 25,000 | ||||||||||||
Employee stock purchase plan termination period | 10 years | ||||||||||||
Expected dividend yield | 0.00% | 0.00% | 0.00% | ||||||||||
2016 Employee Stock Purchase Plan | Subsequent Event | |||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||||||||
Additional number of shares available for issuance | 241,400 |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Employee and Non-Employee Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
Shares Issuable Under Options, Outstanding | 2,361,360 | |
Shares Issuable Under Options, Granted | 1,668,800 | |
Shares Issuable Under Options, Exercised | (521,665) | |
Shares Issuable Under Options, Forfeited | (365,808) | |
Shares Issuable Under Options, Outstanding | 3,142,687 | 2,361,360 |
Shares Issuable Under Options, Options vested and expected to vest | 2,939,785 | |
Shares Issuable Under Options, Options exercisable | 1,160,819 | |
Weighted Average Exercise Price, Outstanding | $ 5.21 | |
Weighted Average Exercise Price, Granted | 8.03 | |
Weighted Average Exercise Price, Exercised | 5.42 | |
Weighted Average Exercise Price, Forfeited | 5.20 | |
Weighted Average Exercise Price, Outstanding | 6.67 | $ 5.21 |
Weighted Average Exercise Price, Options vested and expected to vest | 6.49 | |
Weighted Average Exercise Price, Options exercisable | $ 5.85 | |
Weighted Average Remaining Contractual Term, Outstanding | 8 years 6 months 7 days | 8 years 8 months 19 days |
Weighted Average Remaining Contractual Term, Options vested and expected to vest | 8 years 5 months 12 days | |
Weighted Average Remaining Contractual Term, Options exercisable | 7 years 8 months 4 days | |
Aggregate Intrinsic Value, Outstanding | $ 4,798 | $ 2,482 |
Aggregate Intrinsic Value, Options vested and expected to vest | 4,786 | |
Aggregate Intrinsic Value, Options exercisable | $ 2,470 |
Stock-Based Compensation - Su_2
Stock-Based Compensation - Summary of Employee and Non-Employee Restricted Stock Activity (Details) - Unvested Restricted Common Stock | 12 Months Ended |
Dec. 31, 2018$ / sharesshares | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Shares, Unvested restricted common stock, Beginning balance | shares | 33,307 |
Shares, Vested | shares | (26,444) |
Shares, Unvested restricted common stock, Ending balance | shares | 6,863 |
Weighted Average Grant Date Fair Value, Unvested restricted common stock, Beginning balance | $ / shares | $ 1.84 |
Weighted Average Grant Date Fair Value, Vested | $ / shares | 1.87 |
Weighted Average Grant Date Fair Value, Unvested restricted common stock, Ending balance | $ / shares | $ 1.73 |
Stock-Based Compensation - Su_3
Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - 2018 Equity Inducement Plan and 2016 Employee Stock Purchase Plan - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | $ 4,046 | $ 2,492 | $ 1,221 |
Non-Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | 234 | ||
Research and Development | Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | 1,440 | 961 | 389 |
Research and Development | Non-Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | 234 | ||
General and Administrative | Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | $ 2,606 | $ 1,531 | $ 832 |
Stock-Based Compensation - Su_4
Stock-Based Compensation - Summary of Weighted-Average Assumptions Used in Calculating Fair Value of Awards (Details) | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Dividend yield | 0.00% | ||
2018 Plan, 2016 Plan and 2015 Plan | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Expected term (in years) | 5 years 2 months 12 days | 5 years 10 months 17 days | 5 years 11 months 26 days |
Expected volatility | 74.00% | 86.00% | 87.00% |
Risk-free interest | 2.42% | 2.00% | 1.28% |
Dividend yield | 0.00% | 0.00% | 0.00% |
2016 Employee Stock Purchase Plan | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Expected term (in years) | 6 months | 6 months | 5 months 12 days |
Expected volatility | 66.00% | 78.00% | 82.00% |
Risk-free interest | 2.20% | 1.06% | 0.50% |
Dividend yield | 0.00% | 0.00% | 0.00% |
Defined Contribution Plan - Add
Defined Contribution Plan - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Compensation And Retirement Disclosure [Abstract] | |||
Defined contribution plan, contribution amount | $ 0.2 | $ 0.1 | $ 0.1 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Income Taxes [Line Items] | |||
Provision or benefit from income taxes | $ 0 | $ 0 | $ 0 |
Corporate income tax rates | 21.00% | ||
Orphan drug credit of qualifying expenditures percentage | 25.00% | ||
Effect of tax cuts and jobs act on income tax | $ 0 | 7,869,000 | |
Net operating loss carryforwards | 96,600,000 | 58,000,000 | |
Unrecognized tax benefit | $ 0 | 0 | |
Earliest Tax Year | |||
Income Taxes [Line Items] | |||
Net operating loss carryforwards, expiration year | 2,033 | ||
Tax credit carryforwards, expiration year | 2,033 | ||
Tax Cuts and Jobs Act of 2017 | |||
Income Taxes [Line Items] | |||
Increase in valuation allowance | $ 9,800,000 | 2,700,000 | 9,400,000 |
Federal | |||
Income Taxes [Line Items] | |||
Tax credit carryforwards | 7,300,000 | 5,600,000 | |
State | |||
Income Taxes [Line Items] | |||
Tax credit carryforwards | 400,000 | 1,000,000 | |
PATH Act of 2015 | |||
Income Taxes [Line Items] | |||
Converted research tax credit to offset payroll tax liabilities | 0 | 500,000 | $ 0 |
PATH Act of 2015 | Prepaid Expenses and Other Current Assets | |||
Income Taxes [Line Items] | |||
Payroll tax credit receivable | 300,000 | 400,000 | |
PATH Act of 2015 | Other Noncurrent Assets | |||
Income Taxes [Line Items] | |||
Payroll tax credit receivable | $ 0 | $ 100,000 | |
Maximum | |||
Income Taxes [Line Items] | |||
Corporate income tax rates | 35.00% | ||
Orphan drug credit of qualifying expenditures percentage | 50.00% |
Income Taxes - Difference Betwe
Income Taxes - Difference Between Provision for Income Taxes and Amounts Computed by Applying Statutory Federal Income Tax Rate to Income Before Income Taxes (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Income Taxes [Line Items] | |||
Tax provision derived by applying the federal statutory rate to income before income taxes | $ (9,313,000) | $ (9,260,000) | $ (7,377,000) |
Permanent differences and other | 264,000 | 296,000 | 333,000 |
Change in tax rate | 0 | 7,869,000 | |
Change in the valuation allowance | 9,796,000 | 2,673,000 | 9,369,000 |
Income tax expense /(benefit) | 0 | 0 | 0 |
Federal | |||
Income Taxes [Line Items] | |||
Tax credits | (1,211,000) | (1,294,000) | (1,921,000) |
State | |||
Income Taxes [Line Items] | |||
Tax credits | $ 464,000 | $ (284,000) | $ (404,000) |
Income Taxes - Components of De
Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Deferred tax assets | ||
Net operating loss carryforward | $ 20,276 | $ 12,170 |
Intangible assets | 38 | 29 |
Accrued expense | 508 | 333 |
Stock-based compensation | 682 | 386 |
Other | 73 | 75 |
Total deferred tax assets | 29,196 | 19,389 |
Deferred tax liabilities | ||
Depreciable assets | (74) | (63) |
Total deferred tax liabilities | (74) | (63) |
Less: Valuation allowance | (29,122) | (19,326) |
Deferred tax assets, net | 0 | 0 |
Federal | ||
Deferred tax assets | ||
Tax credits | 7,260 | 5,572 |
State | ||
Deferred tax assets | ||
Tax credits | $ 359 | $ 824 |
Net Loss Per Share - Weighted-A
Net Loss Per Share - Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Series A Convertible Preferred Stock | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 611,392 | ||
Series B Convertible Preferred Stock | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 1,407,097 | ||
Unvested Restricted Common Stock | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 26,841 | 57,629 | 100,634 |
Options to Purchase Common Stock | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 3,014,984 | 2,043,420 | 1,063,778 |
Research and License Agreemen_2
Research and License Agreements - Additional Information (Detail) | 1 Months Ended | 12 Months Ended | ||
Jan. 31, 2017USD ($)LicenseAgreement | Dec. 31, 2018USD ($) | Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | |
License Agreements | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Research agreement date | 2013-12 | |||
Number of license agreements | LicenseAgreement | 2 | |||
Maximum future contingent license payment | $ 6,400,000 | |||
Aggregate potential milestone payments for receipt of regulatory approval | 5,000,000 | |||
Aggregate potential milestone payments for final regulatory approval of second indication | $ 500,000 | |||
Annual license fees paid | $ 50,000 | $ 30,000 | $ 10,000 | |
License Agreements | Minimum | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Rate of revenue share | 6.50% | |||
License Agreements | Maximum | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Rate of revenue share | 25.00% | |||
University Research Agreement | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Payments pursuant to research agreements | $ 200,000 | $ 600,000 | $ 800,000 |
Related Party Transactions - Ad
Related Party Transactions - Additional Information (Details) - One Of The Founders - USD ($) | 2 Months Ended | 10 Months Ended | 12 Months Ended | ||
Dec. 31, 2018 | Nov. 06, 2018 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Related Party Transaction [Line Items] | |||||
Annual consulting fees to company founder | $ 50,000 | ||||
Consulting fees | 0 | $ 50,000 | $ 50,000 | ||
Outstanding liability to related party | $ 0 | $ 0 | $ 0 | ||
Exercise period | 180 days | 90 days | |||
Stock Option | |||||
Related Party Transaction [Line Items] | |||||
Shares issued to related party converted into stock options | 13,852 | ||||
Unvested Restricted Common Stock | |||||
Related Party Transaction [Line Items] | |||||
Shares issued to related party converted into restricted stock awards | 43,290 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Commitments and Contingencies [Line Items] | |||
Security deposit of lease agreement | $ 48,000 | ||
Rent expense | $ 400,000 | $ 400,000 | $ 200,000 |
Austin, TX | Office Space | |||
Commitments and Contingencies [Line Items] | |||
Operating lease agreement, commencement date | 2015-01 | ||
Operating lease agreement, amended date | 2016-09 | ||
Operating lease agreement, expiration date | Dec. 31, 2020 | ||
Tenant improvements allowances on both the original space and expansion space | $ 200,000 | ||
Austin, TX | Laboratory Space | |||
Commitments and Contingencies [Line Items] | |||
Operating lease agreement, commencement date | 2017-02 | ||
Operating lease agreement, amended date | 2018-10 | ||
Operating lease agreement new lease sign date | 2017-10 | ||
Operating lease new agreement, commencement date | 2018-01 | ||
Operating lease extension term | Sep. 30, 2021 |
Commitments and Contingencies_2
Commitments and Contingencies - Summary of Future Annual Minimum Lease Payments Due Under Non-cancellable Operating Leases (Details) $ in Thousands | Dec. 31, 2018USD ($) |
Commitments And Contingencies Disclosure [Abstract] | |
2,019 | $ 397 |
2,020 | 409 |
2,021 | 83 |
Total minimum lease payments | $ 889 |
Subsequent Events - Additional
Subsequent Events - Additional Information (Details) - Common Stock - USD ($) $ / shares in Units, $ in Millions | Apr. 12, 2016 | Feb. 28, 2019 | Apr. 30, 2018 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 |
Subsequent Event [Line Items] | ||||||
Number of shares issued | 5,046,510 | 6,893,000 | 3,000,000 | 5,482,000 | ||
Public offering price | $ 8 | |||||
Underwriting discounts and commissions | $ 2.4 | |||||
Offering costs | $ 0.3 | |||||
Underwriters' Over-allotment Option | ||||||
Subsequent Event [Line Items] | ||||||
Number of shares issued | 481,940 | 546,510 | ||||
2018 Equity Inducement Plan | Subsequent Event | ||||||
Subsequent Event [Line Items] | ||||||
Number of shares issued | 4,625,000 | |||||
Public offering price | $ 8 | |||||
Warrants to purchase shares | 4,000,000 | |||||
Public offering price of warrant | $ 7.9999 | |||||
Net proceeds from sale of common stock | $ 64.5 | |||||
Underwriting discounts and commissions | 4.1 | |||||
Offering costs | $ 0.4 | |||||
2018 Equity Inducement Plan | Subsequent Event | Underwriters' Over-allotment Option | ||||||
Subsequent Event [Line Items] | ||||||
Number of shares issued | 1,125,000 |
Selected Quarterly Financial _3
Selected Quarterly Financial Data (Unaudited) - Schedule of Selected Quarterly Results from Operations (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Selected Quarterly Financial Information [Abstract] | |||||||||||
Grant revenues | $ 0 | $ 0 | $ 2,378 | $ 1,510 | $ 1,483 | $ 1,261 | $ 1,479 | $ 982 | $ 3,888 | $ 5,205 | $ 4,628 |
Type of revenue [extensible list] | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember |
Loss from operations | $ (15,305) | $ (12,243) | $ (9,670) | $ (8,245) | $ (6,627) | $ (7,998) | $ (6,720) | $ (6,331) | $ (45,463) | $ (27,676) | $ (21,906) |
Net loss | $ (14,898) | $ (11,917) | $ (9,414) | $ (8,119) | $ (6,483) | $ (7,874) | $ (6,632) | $ (6,247) | $ (44,348) | $ (27,236) | $ (21,698) |
Basic and diluted net loss per common share | $ (0.62) | $ (0.54) | $ (0.46) | $ (0.49) | $ (0.39) | $ (0.48) | $ (0.47) | $ (0.47) | $ (2.13) | $ (1.80) | $ (2.22) |