Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2019 | Oct. 31, 2019 | |
Cover [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Sep. 30, 2019 | |
Document Fiscal Year Focus | 2019 | |
Document Fiscal Period Focus | Q3 | |
Trading Symbol | GTHX | |
Entity Registrant Name | G1 THERAPEUTICS, INC. | |
Entity Central Index Key | 0001560241 | |
Current Fiscal Year End Date | --12-31 | |
Title of 12(b) Security | Common Stock, par value $0.0001 per share | |
Security Exchange Name | NASDAQ | |
Entity Incorporation, State or Country Code | DE | |
Entity Filer Category | Large Accelerated Filer | |
Entity Common Stock, Shares Outstanding | 37,581,512 | |
Entity Small Business | false | |
Entity Emerging Growth Company | false | |
Entity Current Reporting Status | Yes | |
Entity Shell Company | false | |
Entity File Number | 001-38096 | |
Entity Address, Address Line One | 700 Park Offices Drive | |
Entity Address, Address Line Two | Suite 200 | |
Entity Address, City or Town | Research Triangle Park | |
Entity Address, State or Province | NC | |
Entity Address, Postal Zip Code | 27709 | |
City Area Code | (919) | |
Local Phone Number | 213-9835 | |
Entity Tax Identification Number | 26-3648180 | |
Document Quarterly Report | true | |
Document Transition Report | false | |
Entity Interactive Data Current | Yes |
Condensed Balance Sheets (unaud
Condensed Balance Sheets (unaudited) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Current assets | ||
Cash and cash equivalents | $ 299,933 | $ 369,290 |
Restricted Cash | 63 | |
Prepaid expenses and other current assets | 2,984 | 843 |
Total current assets | 302,980 | 370,133 |
Property and equipment, net | 3,618 | 1,137 |
Restricted Cash | 437 | |
Operating lease assets | 10,151 | |
Total assets | 317,186 | 371,270 |
Current liabilities | ||
Accounts payable | 7,236 | 3,377 |
Accrued expenses | 13,514 | 8,985 |
Other current liabilities | 472 | |
Total current liabilities | 21,222 | 12,362 |
Operating lease liabilities | 9,845 | |
Other non-current liabilities | 88 | |
Total liabilities | 31,067 | 12,450 |
Stockholders’ equity | ||
Common stock, $0.0001 par value, 120,000,000 shares authorized as of September 30, 2019 and December 31, 2018, respectively; 37,608,178 and 37,268,792 shares issued as of September 30, 2019 and December 31, 2018, respectively; 37,581,512 and 37,242,126 shares outstanding as of September 30, 2019 and December 31, 2018, respectively | 4 | 4 |
Treasury stock, 26,666 shares | (8) | (8) |
Additional paid-in capital | 587,535 | 573,230 |
Accumulated deficit | (301,412) | (214,406) |
Total stockholders’ equity | 286,119 | 358,820 |
Total liabilities and stockholders' equity | $ 317,186 | $ 371,270 |
Condensed Balance Sheets (Paren
Condensed Balance Sheets (Parenthetical) (unaudited) - $ / shares | Sep. 30, 2019 | Dec. 31, 2018 |
Statement Of Financial Position [Abstract] | ||
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized | 120,000,000 | 120,000,000 |
Common stock, shares, issued | 37,608,178 | 37,268,792 |
Common stock, shares, outstanding | 37,581,512 | 37,242,126 |
Treasury stock, shares | 26,666 | 26,666 |
Condensed Statements of Operati
Condensed Statements of Operations (unaudited) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Operating expenses | ||||
Research and development | $ 22,941 | $ 15,873 | $ 64,510 | $ 51,605 |
General and administrative | 11,083 | 4,949 | 27,979 | 11,595 |
Total operating expenses | 34,024 | 20,822 | 92,489 | 63,200 |
Operating loss | (34,024) | (20,822) | (92,489) | (63,200) |
Other income (expense) | ||||
Other income | 1,660 | 904 | 5,483 | 2,003 |
Total other income, net | 1,660 | 904 | 5,483 | 2,003 |
Net loss | $ (32,364) | $ (19,918) | $ (87,006) | $ (61,197) |
Net loss per share, basic and diluted | $ (0.86) | $ (0.59) | $ (2.32) | $ (1.91) |
Weighted average common shares outstanding, basic and diluted | 37,540,380 | 33,829,437 | 37,469,952 | 32,006,978 |
Condensed Statements of Stockho
Condensed Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands | Total | Common Stock | Treasury Stock | Additional Paid-in Capital | Accumulated Deficit |
Balance at Dec. 31, 2017 | $ 93,388 | $ 3 | $ (8) | $ 222,511 | $ (129,118) |
Balance (in shares) at Dec. 31, 2017 | 28,420,511 | (26,666) | |||
Public offering (Follow-on Financings) | 108,424 | 108,424 | |||
Public offering (Follow-on Financings), shares | 3,910,000 | ||||
Exercise of common stock options | 647 | 647 | |||
Exercise of common stock options (in shares) | 381,040 | ||||
Stock-based compensation | 1,594 | 1,594 | |||
Stock financing costs | (488) | (488) | |||
Net loss during quarter | (20,410) | (20,410) | |||
Balance at Mar. 31, 2018 | 183,155 | $ 3 | $ (8) | 332,688 | (149,528) |
Balance (in shares) at Mar. 31, 2018 | 32,711,551 | (26,666) | |||
Balance at Dec. 31, 2017 | 93,388 | $ 3 | $ (8) | 222,511 | (129,118) |
Balance (in shares) at Dec. 31, 2017 | 28,420,511 | (26,666) | |||
Net loss during quarter | (61,197) | ||||
Balance at Sep. 30, 2018 | 379,255 | $ 4 | $ (8) | 569,573 | (190,314) |
Balance (in shares) at Sep. 30, 2018 | 37,165,969 | (26,666) | |||
Balance at Mar. 31, 2018 | 183,155 | $ 3 | $ (8) | 332,688 | (149,528) |
Balance (in shares) at Mar. 31, 2018 | 32,711,551 | (26,666) | |||
Public offering (ATM) | 12,059 | 12,059 | |||
Exercise of common stock options (in shares) | 255,007 | ||||
Exercise of common stock options | 261 | 261 | |||
Exercise of common stock options (in shares) | 137,873 | ||||
Stock-based compensation | 2,101 | 2,101 | |||
Stock financing costs | (184) | (184) | |||
Net loss during quarter | (20,868) | (20,868) | |||
Balance at Jun. 30, 2018 | 176,524 | $ 3 | $ (8) | 346,925 | (170,396) |
Balance (in shares) at Jun. 30, 2018 | 33,104,431 | (26,666) | |||
Public offering (Follow-on Financings) | 195,098 | $ 1 | 195,097 | ||
Public offering (Follow-on Financings), shares | 3,450,000 | ||||
Public offering (ATM) | 24,009 | 24,009 | |||
Exercise of common stock options (in shares) | 497,001 | ||||
Exercise of common stock options | 506 | 506 | |||
Exercise of common stock options (in shares) | 114,537 | ||||
Stock-based compensation | 3,276 | 3,276 | |||
Stock financing costs | (240) | (240) | |||
Net loss during quarter | (19,918) | (19,918) | |||
Balance at Sep. 30, 2018 | 379,255 | $ 4 | $ (8) | 569,573 | (190,314) |
Balance (in shares) at Sep. 30, 2018 | 37,165,969 | (26,666) | |||
Balance at Dec. 31, 2018 | 358,820 | $ 4 | $ (8) | 573,230 | (214,406) |
Balance (in shares) at Dec. 31, 2018 | 37,268,792 | (26,666) | |||
Exercise of common stock options | 269 | 269 | |||
Exercise of common stock options (in shares) | 218,890 | ||||
Stock-based compensation | 3,804 | 3,804 | |||
Net loss during quarter | (23,952) | (23,952) | |||
Balance at Mar. 31, 2019 | 338,941 | $ 4 | $ (8) | 577,303 | (238,358) |
Balance (in shares) at Mar. 31, 2019 | 37,487,682 | (26,666) | |||
Balance at Dec. 31, 2018 | $ 358,820 | $ 4 | $ (8) | 573,230 | (214,406) |
Balance (in shares) at Dec. 31, 2018 | 37,268,792 | (26,666) | |||
Exercise of common stock options (in shares) | 339,386 | ||||
Net loss during quarter | $ (87,006) | ||||
Balance at Sep. 30, 2019 | 286,119 | $ 4 | $ (8) | 587,535 | (301,412) |
Balance (in shares) at Sep. 30, 2019 | 37,608,178 | (26,666) | |||
Balance at Mar. 31, 2019 | 338,941 | $ 4 | $ (8) | 577,303 | (238,358) |
Balance (in shares) at Mar. 31, 2019 | 37,487,682 | (26,666) | |||
Exercise of common stock options | 678 | 678 | |||
Exercise of common stock options (in shares) | 42,925 | ||||
Stock-based compensation | 3,741 | 3,741 | |||
Net loss during quarter | (30,690) | (30,690) | |||
Balance at Jun. 30, 2019 | 312,670 | $ 4 | $ (8) | 581,722 | (269,048) |
Balance (in shares) at Jun. 30, 2019 | 37,530,607 | (26,666) | |||
Exercise of common stock options | 1,372 | 1,372 | |||
Exercise of common stock options (in shares) | 77,571 | ||||
Stock-based compensation | 4,441 | 4,441 | |||
Net loss during quarter | (32,364) | (32,364) | |||
Balance at Sep. 30, 2019 | $ 286,119 | $ 4 | $ (8) | $ 587,535 | $ (301,412) |
Balance (in shares) at Sep. 30, 2019 | 37,608,178 | (26,666) |
Condensed Statements of Cash Fl
Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Cash flows from operating activities | ||
Net loss | $ (87,006) | $ (61,197) |
Adjustments to reconcile net loss to net cash used in operating activities | ||
Depreciation and amortization | 215 | 115 |
Stock-based compensation | 11,986 | 6,971 |
Gain/loss on disposal of property and equipment | 7 | |
Change in operating assets and liabilities | ||
Prepaid expenses and other assets | (772) | (510) |
Accounts payable | 2,574 | (1,648) |
Accrued expenses and other liabilities | 3,443 | 3,167 |
Deferred rent | 16 | |
Net cash used in operating activities | (69,560) | (53,079) |
Cash flows from investing activities | ||
Purchases of property and equipment | (1,616) | (598) |
Investment in restricted cash account | (500) | |
Net cash used in investing activities | (2,116) | (598) |
Cash flows from financing activities | ||
Proceeds from stock options and warrants exercised | 2,319 | 1,414 |
Proceeds from public offerings, net of underwriting fees and commissions | 339,589 | |
Payment of public offering costs | (614) | |
Net cash provided by financing activities | 2,319 | 340,389 |
Net change in cash, cash equivalents and restricted cash | (69,357) | 286,712 |
Cash, cash equivalents and restricted cash | ||
Beginning of period | 369,290 | 103,812 |
End of period | 299,933 | 390,524 |
Non-cash operating, investing and financing activities | ||
Upfront project costs and other current assets in accounts payable and accrued expenses | 1,040 | 130 |
Purchases of equipment in accounts payable and accrued expenses | 1,080 | 19 |
Operating lease liabilities arising from obtaining right-of-use asset | $ 8,947 | |
Costs for public offering in accounts payable and accrued expenses | $ 297 |
Business Description
Business Description | 9 Months Ended |
Sep. 30, 2019 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Business Description | 1. Business Description G1 Therapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company based in Research Triangle Park, North Carolina focused on the discovery, development and commercialization of novel small molecule therapeutics for the treatment of patients with cancer. The Company was incorporated on May 19, 2008 in the state of Delaware. The Company is advancing three clinical-stage programs. Trilaciclib is a first-in-class therapy designed to improve outcomes for patients being treated with chemotherapy. Lerociclib is a differentiated oral CDK4/6 inhibitor designed to enable more effective combination treatment strategies across multiple oncology indications, including estrogen receptor-positive, HER2-negative (ER+, HER2-) breast cancer. G1T48 is a potential best-in-class oral selective estrogen receptor degrader (SERD) for the treatment of ER+ breast cancer. The Company also has an active discovery program focused on cyclin-dependent kinase targets. The Company owns the global rights to all of its product candidates. Trilaciclib, the Company’s most advanced clinical-stage candidate, is a first-in-class therapy designed to preserve bone marrow and immune system function during chemotherapy and improve patient outcomes. The U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for trilaciclib based on myelopreservation data from three randomized, double-blind, placebo-controlled small cell lung cancer (SCLC) clinical trials, as well as safety data collected across all completed and ongoing clinical trials. The Breakthrough Therapy program is designed to expedite development and review of drugs intended for serious or life-threatening conditions. Based on written feedback from its pre-New Drug Application (NDA) meeting with the FDA, the Company plans to begin a rolling NDA submission for trilaciclib for myelopreservation in SCLC in the fourth quarter of 2019 and complete the NDA submission in the second quarter of 2020. Based on discussions with European regulatory authorities, the Company plans to submit a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) for trilaciclib for myelopreservation in SCLC in the second half of 2020. In September, the Company presented updated data from a randomized Phase 2 trial of trilaciclib in combination with chemotherapy in metastatic triple-negative breast cancer (mTNBC) demonstrating significant improvement in overall survival. These data were presented at the European Society for Medical Oncology (ESMO) Congress in September 2019 and published in The Lancet Oncology. The Company has shared the findings with the FDA. The Company plans to initiate additional clinical trials beginning in 2020 to evaluate the use of trilaciclib in additional tumor types and in combination with different chemotherapy regimens. Lerociclib is a differentiated oral CDK4/6 inhibitor being developed for use in combination with other targeted therapies in multiple oncology indications, including ER+, HER2- breast cancer. In 2018, the Company reported encouraging preliminary Phase 1b data from its Phase 1/2 trial in ER+, HER2- breast cancer (in combination with fulvestrant) and will report additional Phase 1b/2a data from this trial at the San Antonio Breast Cancer Symposium on December 11, 2019. In 2020, the Company plans to initiate a pivotal trial to evaluate lerociclib in combination with fulvestrant for the treatment of ER+, HER2- breast cancer. The Company’s plans for lerociclib include potential exploration of combinations in other cancers, such as non-small cell lung cancer (NSCLC), where we initiated a Phase 1b/2 trial in 2018 in combination with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, Tagrisso® (osimertinib). Data from this trial were presented at the ESMO 2019 Congress. We believe that lerociclib has the potential to be best-in-class versus marketed CDK4/6 inhibitors for patients with ER+, HER2- breast cancer and become a backbone therapy of multiple combination targeted therapy regimens for other tumors. The Company is developing G1T48, a potential best-in-class oral SERD, as a monotherapy and in combination with oral CDK4/6 inhibitors (including lerociclib) for the treatment of ER+ breast cancer. In 2018, the Company initiated a Phase 1/2a clinical trial in ER+, HER2- breast cancer and reported preliminary data at the ESMO 2019 Congress. Based on these findings, G1 is planning to initiate a pivotal trial of G1T48 in combination with an oral CDK4/6 inhibitor in 2020. All three investigational therapies have the potential to become new standards of care for women with breast cancer and provide benefit in the early stages of their disease, including in the adjuvant setting. |
Basis of Presentation and Summa
Basis of Presentation and Summary of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2019 | |
Accounting Policies [Abstract] | |
Basis of Presentation and Summary of Significant Accounting Policies | 2. Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). In the opinion of management, the Company has made all necessary adjustments, which include normal recurring adjustments necessary for a fair statement of the Company’s financial position and results of operations for the interim periods presented. The information presented in the condensed financial statements and related notes as of September 30, 2019, and for the three and nine months ended September 30, 2019 and 2018, is unaudited. The results for the three months ended September 30, 2019 are not necessarily indicative of the results expected for the full fiscal year or any future period. These interim financial statements should be read in conjunction with the financial statements and notes set forth in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 28, 2019, as amended on April 26, 2019 (collectively, “2018 Form 10-K”). The December 31, 2018 condensed balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures, including notes, required by U.S. GAAP for complete financial statements. 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 financial statements and the accompanying notes. On an ongoing basis, the Company’s management evaluates its estimates which include, but are not limited to, estimates related to accrued expenses, accrued external clinical costs, stock-based compensation expense and deferred tax asset valuation allowance. The Company bases its estimates on historical experience and other market specific or other relevant assumptions it believes to be reasonable under the circumstances. Actual results could differ from those estimates. Research and Development Research and development expenses consist of costs incurred to further the Company’s research and development activities and include salaries and related employee benefits, manufacturing of pharmaceutical active ingredients and drug products, costs associated with clinical trials, nonclinical activities, regulatory activities, research-related overhead expenses and fees paid to expert consultants, external service providers and contract research organizations which conduct certain research and development activities on behalf of the Company. Costs incurred in the research and development of products are charged to research and development expense as incurred. Each reporting period, management estimated and accrued research and development expenses, including external clinical study costs comprising of pre-clinical and clinical trial activities. The process involves reviewing contracts and purchase orders, identifying services that have been provided on the Company’s behalf, and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual costs. Costs for preclinical studies and clinical trial activities were estimated based on an evaluation of vendors’ progress towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided by vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services were performed. The Company determines accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of trials, or the services completed. The estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. Income taxes The Company did not record a federal or state income tax benefit for the nine months ended September 30, 2019 due to its conclusion that a full valuation allowance is required against the Company’s deferred tax assets. Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statements carrying amounts of assets and liabilities and their respective tax bases, operating loss carryforwards, and tax credit carryforwards. 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 be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. In accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 740, Accounting for Income Taxes correspondingly there is no impact on the Company’s effective income tax rate associated with these items. The Company’s policy for recording interest and penalties relating to uncertain income tax positions is to record them as a component of income tax expense in the accompanying statements of operati ons. As of September 30, 2019 and December 31, 2018 , the Company had no such accruals. The Company had federal and state operating loss carryforwards of approximately $191.5 million that expire beginning in 2024 as of its fiscal year ending December 31, 2018 prior to any reductions under Section 382 of the Internal Revenue Code of 1986, as amended. Section 382 provides that a corporation that undergoes an “ownership change”, as defined therein, is subject to limitations on its ability to use its pre-change net operating loss carryforwards to offset future taxable income. In April 2019, the Company completed an evaluation study whether an “ownership change” had occurred and determined that the limitation would be approximately $8.0 million, thereby reducing the net operating loss which remains approximately $183.5 million at September 30, 2019. The Company continues to maintain a valuation allowance on the remaining NOL as it believes that it is more likely than not that all of the deferred tax asset associated with the NOLs will not be realized regardless of whether an “ownership change” has occurred. Stock-Based Compensation The primary type of stock-based payments utilized by the Company are stock options. The Company accounts for stock-based employee compensation arrangements by measuring the cost of employee services received in exchange for all equity awards granted based on the fair value of the award on the grant date. The fair value of each employee stock option is estimated on the date of grant using an options pricing model. The Company currently uses the Black-Scholes valuation model to estimate the fair value of its share-based payments. The model requires management to make a number of assumptions including expected volatility, expected life, risk-free interest rate and expected dividends. The Company accounts for stock-based non-employee compensation arrangements by recording the expense of such services based on the fair value of the equity instrument as estimated using the Black-Scholes pricing model. The fair value of the equity instrument is charged to operating expense over the term of the service agreement. In accordance with the implementation of ASU No. 2018-07 on January 1, 2019, the fair value of non-employee stock options will no longer be re-measured each reporting period. Leases We determine if an arrangement is a lease at inception. Operating lease assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating leases are included in operating lease assets, other current liabilities, and operating lease liabilities on our balance sheet at September 30, 2019. Operating lease assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date to determine the present value of future payments. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Prior period amounts continue to be reported in accordance with our historic accounting under previous lease guidance, Topic 840. See “Adoption of New Accounting Standards – Impact of Adoption of Topic 842” below, for more information about the impact of the adoption of Topic 842. Recent Accounting Pronouncements Adoption of New Accounting Standards In June 2018, the FASB issued ASU No. 2018-07, Improvements to Nonemployee Share-Based Payment Accounting In February 2016, the FASB issued ASU No. 2016-02, Leases Impact of Adoption of Topic 842 With the adoption of Topic 842 on January 1, 2019, the Company recognized operating lease assets and operating lease liabilities of $1.5 million and $1.6 million, respectively, with the difference due to the de-recognition of current and non-current deferred rent. There was no impact to the opening accumulated deficit as of January 1, 2019. The impact of the adoption of Topic 842 on the accompanying balance sheet as of January 1, 2019 was as follows (in thousands): December 31, 2018 Adjustments Due to the Adoption of Topic 842 January 1, 2019 Operating lease assets $ — $ 1,533 $ 1,533 Accrued expenses 8,985 (9 ) 8,976 Operating lease liabilities: Other current liabilities — 352 352 Non-current operating lease liabilities — 1,278 1,278 Other non-current liabilities 88 (88 ) — Stockholders' equity 358,820 — 358,820 Recently Issued Accounting Standards In August 2018, the FASB issued ASU No. 2018-15, Goodwill and Other—Internal-Use Software |
Fair Value Measurements
Fair Value Measurements | 9 Months Ended |
Sep. 30, 2019 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. Fair Value Measurements The Company provides disclosure of financial assets and financial liabilities that are carried at fair value based on the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements may be classified based on the amount of subjectivity associated with the inputs to fair valuation of these assets and liabilities using the following three levels: Level 1 Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3 Unobservable inputs that reflect the Company’s estimates of the assumptions that market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available, including its own data. The carrying amounts of cash, cash equivalents, accounts payable and accrued liabilities approximate fair value because of their short-term nature. At September 30, 2019 and December 31, 2018 these financial instruments and respective fair values have been classified as follows (in thousands): Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant other unobservable inputs (Level 3) Balance at September 30, 2019 Assets Money market funds $ 282,727 $ — $ — $ 282,727 Certificates of Deposit 15,796 — — 15,796 Total assets at fair value: $ 298,523 $ — $ — $ 298,523 Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant other unobservable inputs (Level 3) Balance at December 31, 2018 Assets Money market funds $ 352,934 $ — $ — $ 352,934 Certificates of Deposit 15,501 — — 15,501 Total assets at fair value: $ 368,435 $ — $ — $ 368,435 During the three and nine months ended September 30, 2019 and the year ended December 31, 2018, there were no changes in valuation methodology. |
Property and Equipment
Property and Equipment | 9 Months Ended |
Sep. 30, 2019 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment | 4. Property and equipment Property and equipment consists of the following (in thousands): September 30, 2019 December 31, 2018 Computer equipment $ 326 $ 246 Laboratory equipment 817 611 Furniture and fixtures 1,052 293 Leasehold improvements 1,958 238 Construction in progress — 71 Accumulated depreciation (535 ) (322 ) Property and equipment, net $ 3,618 $ 1,137 Depreciation expense relating to property and equipment was $86 and $215 for the three and nine months ended September 30, 2019, respectively and $48 and $115 for the three and nine months ended September 30, 2018, respectively. |
Patent License Agreement
Patent License Agreement | 9 Months Ended |
Sep. 30, 2019 | |
Patent License Agreement [Abstract] | |
Patent License Agreement | 5. Patent license agreement On November 23, 2016, the Company entered into a license agreement with the Board of Trustees of the University of Illinois (“the University”), which was amended on March 24, 2017. Pursuant to the license agreement, as amended, the University licensed patent rights to the Company, with rights of sublicense, to make, have made, use, import, sell and offer for sale products covered by certain patent rights owned by the University. The rights licensed to the Company are exclusive, worldwide, non-transferable rights, for all fields of use. Under the terms of the agreement the Company paid a one-time only, non-refundable license issue fee in the amount of $0.5 million which was charged to research and development expense in the fourth quarter of 2016. The Company is also obligated to pay annual maintenance fees to the University. All annual minimum payments are fully creditable against any royalty payments made by the Company. Under the terms of the agreement, the Company must pay the University a royalty percentage on all net sales of products and a share of sublicensing revenues. In addition, the University is eligible to receive milestone payments of up to $2.6 million related to the initiation and execution of clinical trials and the first commercial sale of a product and the first commercial sale of a product in another country. To date, the Company has made milestone payments totaling $0.6 million, of which $0.5 million was incurred during the current quarter. The Company will be responsible for any future patent prosecution costs that may arise. The term of the license agreement will continue until the later of (i) the expiration of the last valid claim within the patent rights covering the product in such country, (ii) the expiration of market exclusivity in such country and (iii) the 10th anniversary of the first commercial sale in such country. The University may terminate the agreement in the event (i) the Company fails to pay any amount or make any report when required to be made and fails to cure such failure within thirty (30) days after receipt of notice from the University, (ii) is in breach of any provision of the agreement and fails to remedy such breach within forty-five (45) days after receipt of notice, (iii) makes a report to the University under the agreement that is determined to be materially false, (iv) declares insolvency or bankruptcy or (v) takes an action that causes patent rights or technical information to be subject to lien or encumbrance and fails to remedy any such breach with in forty-five (45) days of receipt of notice from the University. The Company may terminate the agreement at any time on written notice to the University at least ninety (90) days prior to the termination date specified in the notice. Upon expiration or termination of the agreement, all rights revert to the University. |
Accrued Expenses
Accrued Expenses | 9 Months Ended |
Sep. 30, 2019 | |
Payables And Accruals [Abstract] | |
Accrued Expenses | 6. Accrued expenses Accrued expenses are comprised as follows (in thousands): September 30, 2019 December 31, 2018 Accrued external research and professional fees $ 4,526 $ 1,591 Accrued external clinical study costs 6,755 4,692 Accrued compensation expense 2,233 2,693 Deferred rent, current portion — 9 Accrued expenses $ 13,514 $ 8,985 |
Leases
Leases | 9 Months Ended |
Sep. 30, 2019 | |
Leases [Abstract] | |
Leases | 7. Leases As described in our “Note 2. Basis of Presentation and Summary of Significant Accounting Policies”, we adopted Topic 842 as of January 1, 2019. Prior period amounts have not been adjusted and continue to be reported in accordance with our historic accounting under Topic 840. Pursuant to a lease agreement dated January 10, 2014 (the “Lease”), on April 1, 2014, the Company leased office and lab space with a free rent period and escalating rent payments; the Lease had an expiration date of July 31, 2017. The Lease was amended on January 27, 2016 to lease new larger office and lab space beginning in August 2016 with a discounted rent period and escalating rent payments and the Lease term was extended to December 31, 2022. The amendment also contained an option for a five-year renewal and a right of first refusal to lease adjacent office space. The Lease was further amended on March 27, 2017 to lease additional office space beginning in August 2017 with a discounted rent period and escalating rent payments. The Lease was amended again in January 2018 to lease additional adjacent office space beginning in August 2018 with a discounted rent period and escalating rent payments. The term of the renewal option contained in the Lease, as amended, was not included in the measurement of the operating lease asset and liability since exercise of the option was uncertain. In November 2018, the Company signed a new lease to secure approximately 60,000 square feet of laboratory and office space at 700 Park Offices Drive in Research Triangle Park, NC (“700 Lease”). The 700 Lease commenced on September 2, 2019 and has an expiration date of September 30, 2027 for the initial term with the Company having the option to renew for an additional 5 years. The term of the renewal option contained in the Lease was not included in the measurement of the operating lease asset and liability since exercise of the option was uncertain. As part of the 700 Lease, the Company obtained a standby letter of credit in the amount of $0.5 million related to the security deposit. This letter of credit is secured by money market funds at the financial institution. Therefore, these funds are classified as restricted cash on the balance sheet. The letter of credit will be reduced ratably on each anniversary of the commencement of the 700 Lease until the end of the lease term. The tables below reflect the Company’s lease position and weighted-average lease terms and discount rates for our operating leases as of September 30, 2019. Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, we use our incremental borrowing rate based on the information available at the lease commencement date. (in thousands) Classification on the Balance Sheet September 30, 2019 Assets Operating lease assets Operating lease assets $ 10,151 Total lease assets $ 10,151 Liabilities Current Operating Other current liabilities $ 472 Non-current Operating Operating lease liabilities 9,845 Total lease liabilities $ 10,317 Lease Term and Discount Rate September 30, 2019 Weighted-average remaining lease term (years) Operating leases 7.4 Weighted-average discount rate Operating leases 7.7 % The table below presents information related to the lease costs for operating leases (in thousands): Three Months Ended September 30, Nine Months Ended September 30, (in thousands) Classification 2019 2018 2019 2018 Operating lease costs (a) Research and development $ 153 $ 75 $ 329 $ 211 General and administrative 92 26 145 53 Total operating lease costs $ 245 $ 101 $ 474 $ 264 (a) Includes variable lease costs which are immaterial The table below reconciles the undiscounted cash flow for each of the first five years and total of the remaining years to the operating lease liabilities recorded on the balance sheet as of September 30, 2019 (in thousands): Operating leases Years ending December 31, 2019 (excluding the nine months ended September 30, 2019) $ 299 2020 1,459 2021 2,015 2022 2,072 2023 1,634 Thereafter 6,534 Total future minimum lease payments $ 14,013 Less: present value adjustment (3,696 ) Total operating lease liabilities $ 10,317 Cash payments included in the measurement of our operating leases were $389 thousand for the nine months ended September 30, 2019. ASC 840 Disclosures The Company elected the alternative modified transition method and included the following table previously disclosed. The following is a schedule by years of minimum future rental payments on noncancelable operating leases as of December 31, 2018 (in thousands): 2019 $ 680 2020 1,427 2021 1,960 2022 2,015 2023 1,577 2024 and thereafter 6,155 $ 13,814 |
Stockholders' Equity
Stockholders' Equity | 9 Months Ended |
Sep. 30, 2019 | |
Class Of Stock Disclosures [Abstract] | |
Stockholders’ Equity | 8. Stockholders’ Equity Common Stock The Company is authorized to issue 120.0 million shares of common stock. Holders of common stock are entitled to one vote per share. Holders of common stock are entitled to receive dividends, as, if and when declared by the Company’s Board of Directors. On March 12, 2018, the Company closed an underwritten public offering of 3,910,000 shares of common stock at a public offering price of $29.50 per share, including 510,000 shares of common stock issued upon exercise by the underwriters of their option to purchase additional shares. The gross proceeds from the offering were $115.3 million and net proceeds were $107.9 million, after deducting underwriting discounts and commissions and other offering expenses payable by the Company. On June 15, 2018, the Company entered into a Sales Agreement for an “at the market offering” arrangement with Cowen and Company, LLC (“Cowen”), which allows the Company to issue and sell shares of common stock pursuant to a shelf registration statement for total gross sales proceeds of up to $125.0 million from time to time through Cowen, acting as its agent. Between June 18, 2018 and August 2, 2018, the Company sold 752,008 shares of common stock pursuant to this agreement resulting in $36.1 million in net proceeds, realizing $12.1 million in the second quarter of 2018 and the remaining $24.0 million by August 2, 2018. On September 21, 2018, the Company closed on an underwritten public offering of 3,450,000 shares of its common stock at a public offering price of $60.00 per share, including 450,000 shares of common stock issued upon exercise by the underwriters of their option to purchase additional shares, pursuant to a shelf registration statement. The gross proceeds from the offering were $207.0 million and net proceeds were $194.9 million, after deducting underwriting discounts and commissions and other offering expenses payable by the Company. Preferred Stock The Company is authorized to issue 5.0 million shares of undesignated preferred stock in one or more series. As of September 30, 2019, no shares of preferred stock were issued or outstanding. Shares Reserved for Future Issuance The Company has reserved for future issuance the following number of shares of common stock: September 30, 2019 December 31, 2018 Common stock options outstanding 5,762,159 4,502,133 Options available for grant under Equity Incentive Plans 950,697 1,547,306 6,712,856 6,049,439 |
Stock-based Compensation
Stock-based Compensation | 9 Months Ended |
Sep. 30, 2019 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stock-based Compensation | 9. Stock-based Compensation 2011 Equity Incentive Plan In March 2011, the Company adopted the 2011 Equity Incentive Plan (the “2011 Plan”). The 2011 Plan provided for the direct award or sale of the Company’s common stock and for the grant of stock options to employees, directors, officers, consultants and advisors of the Company. The 2011 Plan was subsequently amended in August 2012, October 2013, February 2015, December 2015, April 2016 and November 2016 to allow for the issuance of additional shares of common stock. In connection with the adoption of the 2017 Plan (as defined below), the 2011 Plan was terminated and no further awards will be made under the 2011 Plan. 2017 Equity Incentive Plan In May 2017, the Company adopted the 2017 Equity Incentive Plan (the “2017 Plan”). The 2017 Plan provided for the direct award or sale of the Company’s common stock and for the grant of up to 1,932,000 stock options to employees, directors, officers, consultants and advisors of the Company. The 2017 Plan provides for the grant of incentive stock options, non-statutory stock options or restricted stock. Effective January 1, 2018, and in accordance with the “evergreen” provision of the 2017 plan, an additional 1,066,692 shares were made available for issuance. Effective January 1, 2019, and in accordance with the “evergreen” provision of the 2017 plan, an additional 1,096,553 shares were made available for issuance. Under both the 2011 Plan and the 2017 Plan, options to purchase the Company’s common stock may be granted at a price no less than the fair market value of a share of common stock on the date of grant. The fair value shall be the closing sales price for a share as quoted on any established securities exchange for such grant date or the last preceding date for which such quotation exists. Vesting terms of options issued are determined by the Board of Directors or Compensation Committee of the Board. The Company’s stock options vest based on terms in the stock option agreements. Stock options have a maximum term of ten years. As of September 30, 2019, there were a total of 950,697 shares of common stock available for future issuance under the 2017 Plan. Stock Option Expense The Company recognizes compensation costs related to stock options granted to employees based on the estimated fair value of the awards on the date of grant, net of estimated forfeitures. The grant date fair value of the stock-based awards is generally recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the respective awards. Share-based awards granted to non-employee directors as compensation for serving on the Company’s Board of Directors are accounted for in the same manner as employee share-based compensation awards. During the three and nine months ended September 30, 2019, the Company recorded employee share-based compensation expense of $4.4 million and $11.9 million, respectively. During the three and nine months ended September 30, 2018, the Company recorded employee share-based compensation expense of $2.7 million and $5.2 million, respectively. The Company recognizes compensation costs related to stock options granted to non-employees based on the estimated fair value of the awards on the date of grant in the same manner as employees. Prior to the adoption of ASU 2018-07 on January 1, 2019, the fair value of the stock options granted to non-employees was re-measured each reporting period until the service was complete, and the resulting increase or decrease in value, if any, was recognized as expense or income, respectively, during the period the related services were rendered. After the adoption of ASU 2018-07, stock options granted to non-employees are no longer re-measured each reporting period. During the three and nine months ended September 30, 2019, the Company recorded non-employee share-based compensation expense of $0 and $0.1 million, respectively. During the three and nine months ended September 30, 2018, the Company recorded non-employee share-based compensation expense of $0.5 million and $1.8 million, respectively. The Company calculates the fair value of stock options using the Black-Scholes option pricing model. The Black-Scholes option-pricing model requires the use of subjective assumptions, including the expected volatility of the Company’s common stock, the assumed dividend yield, the expected term of the Company’s stock options and the fair value of the underlying common stock on the date of grant. Stock options— Black-Scholes inputs The fair value of stock options was estimated using the following weighted-average assumptions for the three and nine months ended September 30, 2019 and September 30, 2018: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Expected volatility 74.4 - 77.1% 77.3 - 86.4% 74.2 - 82.1% 74.9 - 86.5% Weighted-average risk free rate 1.4 - 1.9% 2.7 - 2.9% 1.4 - 2.6% 2.3 - 2.9% Dividend yield —% —% —% —% Expected term (in years) 6.07 6.06 6.02 6.03 The table below summarizes the stock-based compensation expense recognized in the Company’s statement of operations by classification (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development $ 1,634 $ 1,473 $ 4,635 $ 3,900 General and administrative 2,807 1,803 7,351 3,071 Total stock-based compensation expense $ 4,441 $ 3,276 $ 11,986 $ 6,971 Stock Option Activity Stock option activity for the nine months ended September 30, 2019 is as follows: Weighted average Weighted average Remaining Aggregate Options exercise contractual intrinsic outstanding price life (Years) value (in thousands) Balance as of December 31, 2018 4,502,133 $ 14.13 7.6 $ 46,575 Cancelled (296,113 ) $ 19.96 Granted 1,895,525 22.05 Exercised (339,386 ) 6.83 Balance as of September 30, 2019 5,762,159 $ 16.87 7.7 $ 56,706 Exercisable at December 31, 2018 2,361,694 3.07 6.5 $ 38,285 Vested at December 31, 2018 and expected to vest 4,502,133 14.13 7.6 $ 46,575 Exercisable at September 30, 2019 2,813,106 7.90 6.3 $ 47,709 Vested at September 30, 2019 and expected to vest 5,762,159 16.87 7.7 $ 56,706 |
Net Loss Per Common Share
Net Loss Per Common Share | 9 Months Ended |
Sep. 30, 2019 | |
Earnings Per Share [Abstract] | |
Net Loss Per Common Share | 10. Net loss per common share Basic net loss per common share is computed using the weighted average number of common shares outstanding during the period including nominal issuances of common stock warrants. Diluted net loss per common share is computed using the sum of the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options, stock warrants and unvested restricted common stock. For the three months ended September 30, 2019 and 2018 and for the nine months ended September 30, 2019 and 2018 the following potentially dilutive securities have been excluded from the computations of diluted weighted-average shares outstanding because the effect would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) (unaudited) Stock options issued and outstanding 5,629,344 4,482,649 5,334,298 4,258,269 Amounts in the table above reflect the common stock equivalents of the noted instrument. |
Related Party Transactions
Related Party Transactions | 9 Months Ended |
Sep. 30, 2019 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | 11. Related party transactions The Company maintains a consulting agreement with a member of the Board of Directors for scientific advisory services outside of his role on the Board of Directors that expires on June 30, 2020. |
Basis of Presentation and Sum_2
Basis of Presentation and Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
Sep. 30, 2019 | |
Accounting Policies [Abstract] | |
Basis of Presentation | Basis of Presentation The accompanying condensed financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). In the opinion of management, the Company has made all necessary adjustments, which include normal recurring adjustments necessary for a fair statement of the Company’s financial position and results of operations for the interim periods presented. The information presented in the condensed financial statements and related notes as of September 30, 2019, and for the three and nine months ended September 30, 2019 and 2018, is unaudited. The results for the three months ended September 30, 2019 are not necessarily indicative of the results expected for the full fiscal year or any future period. These interim financial statements should be read in conjunction with the financial statements and notes set forth in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 28, 2019, as amended on April 26, 2019 (collectively, “2018 Form 10-K”). The December 31, 2018 condensed balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures, including notes, required by U.S. GAAP for complete financial statements. |
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 financial statements and the accompanying notes. On an ongoing basis, the Company’s management evaluates its estimates which include, but are not limited to, estimates related to accrued expenses, accrued external clinical costs, stock-based compensation expense and deferred tax asset valuation allowance. The Company bases its estimates on historical experience and other market specific or other relevant assumptions it believes to be reasonable under the circumstances. Actual results could differ from those estimates. |
Research and Development | Research and Development Research and development expenses consist of costs incurred to further the Company’s research and development activities and include salaries and related employee benefits, manufacturing of pharmaceutical active ingredients and drug products, costs associated with clinical trials, nonclinical activities, regulatory activities, research-related overhead expenses and fees paid to expert consultants, external service providers and contract research organizations which conduct certain research and development activities on behalf of the Company. Costs incurred in the research and development of products are charged to research and development expense as incurred. Each reporting period, management estimated and accrued research and development expenses, including external clinical study costs comprising of pre-clinical and clinical trial activities. The process involves reviewing contracts and purchase orders, identifying services that have been provided on the Company’s behalf, and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual costs. Costs for preclinical studies and clinical trial activities were estimated based on an evaluation of vendors’ progress towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided by vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services were performed. The Company determines accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of trials, or the services completed. The estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. |
Income Taxes | Income taxes The Company did not record a federal or state income tax benefit for the nine months ended September 30, 2019 due to its conclusion that a full valuation allowance is required against the Company’s deferred tax assets. Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statements carrying amounts of assets and liabilities and their respective tax bases, operating loss carryforwards, and tax credit carryforwards. 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 be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. In accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 740, Accounting for Income Taxes correspondingly there is no impact on the Company’s effective income tax rate associated with these items. The Company’s policy for recording interest and penalties relating to uncertain income tax positions is to record them as a component of income tax expense in the accompanying statements of operati ons. As of September 30, 2019 and December 31, 2018 , the Company had no such accruals. The Company had federal and state operating loss carryforwards of approximately $191.5 million that expire beginning in 2024 as of its fiscal year ending December 31, 2018 prior to any reductions under Section 382 of the Internal Revenue Code of 1986, as amended. Section 382 provides that a corporation that undergoes an “ownership change”, as defined therein, is subject to limitations on its ability to use its pre-change net operating loss carryforwards to offset future taxable income. In April 2019, the Company completed an evaluation study whether an “ownership change” had occurred and determined that the limitation would be approximately $8.0 million, thereby reducing the net operating loss which remains approximately $183.5 million at September 30, 2019. The Company continues to maintain a valuation allowance on the remaining NOL as it believes that it is more likely than not that all of the deferred tax asset associated with the NOLs will not be realized regardless of whether an “ownership change” has occurred. |
Stock-Based Compensation | Stock-Based Compensation The primary type of stock-based payments utilized by the Company are stock options. The Company accounts for stock-based employee compensation arrangements by measuring the cost of employee services received in exchange for all equity awards granted based on the fair value of the award on the grant date. The fair value of each employee stock option is estimated on the date of grant using an options pricing model. The Company currently uses the Black-Scholes valuation model to estimate the fair value of its share-based payments. The model requires management to make a number of assumptions including expected volatility, expected life, risk-free interest rate and expected dividends. The Company accounts for stock-based non-employee compensation arrangements by recording the expense of such services based on the fair value of the equity instrument as estimated using the Black-Scholes pricing model. The fair value of the equity instrument is charged to operating expense over the term of the service agreement. In accordance with the implementation of ASU No. 2018-07 on January 1, 2019, the fair value of non-employee stock options will no longer be re-measured each reporting period. |
Leases | Leases We determine if an arrangement is a lease at inception. Operating lease assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating leases are included in operating lease assets, other current liabilities, and operating lease liabilities on our balance sheet at September 30, 2019. Operating lease assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date to determine the present value of future payments. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Prior period amounts continue to be reported in accordance with our historic accounting under previous lease guidance, Topic 840. See “Adoption of New Accounting Standards – Impact of Adoption of Topic 842” below, for more information about the impact of the adoption of Topic 842. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements Adoption of New Accounting Standards In June 2018, the FASB issued ASU No. 2018-07, Improvements to Nonemployee Share-Based Payment Accounting In February 2016, the FASB issued ASU No. 2016-02, Leases Impact of Adoption of Topic 842 With the adoption of Topic 842 on January 1, 2019, the Company recognized operating lease assets and operating lease liabilities of $1.5 million and $1.6 million, respectively, with the difference due to the de-recognition of current and non-current deferred rent. There was no impact to the opening accumulated deficit as of January 1, 2019. The impact of the adoption of Topic 842 on the accompanying balance sheet as of January 1, 2019 was as follows (in thousands): December 31, 2018 Adjustments Due to the Adoption of Topic 842 January 1, 2019 Operating lease assets $ — $ 1,533 $ 1,533 Accrued expenses 8,985 (9 ) 8,976 Operating lease liabilities: Other current liabilities — 352 352 Non-current operating lease liabilities — 1,278 1,278 Other non-current liabilities 88 (88 ) — Stockholders' equity 358,820 — 358,820 Recently Issued Accounting Standards In August 2018, the FASB issued ASU No. 2018-15, Goodwill and Other—Internal-Use Software |
Basis of Presentation and Sum_3
Basis of Presentation and Summary of Significant Accounting Policies (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
ASU 2016-02 (Topic 842) | |
Schedule of Impact of Adoption of Topic 842 on Accompanying Balance Sheet | The impact of the adoption of Topic 842 on the accompanying balance sheet as of January 1, 2019 was as follows (in thousands): December 31, 2018 Adjustments Due to the Adoption of Topic 842 January 1, 2019 Operating lease assets $ — $ 1,533 $ 1,533 Accrued expenses 8,985 (9 ) 8,976 Operating lease liabilities: Other current liabilities — 352 352 Non-current operating lease liabilities — 1,278 1,278 Other non-current liabilities 88 (88 ) — Stockholders' equity 358,820 — 358,820 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Fair Value Disclosures [Abstract] | |
Summary of Financial Instruments and Respective Fair Values | At September 30, 2019 and December 31, 2018 these financial instruments and respective fair values have been classified as follows (in thousands): Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant other unobservable inputs (Level 3) Balance at September 30, 2019 Assets Money market funds $ 282,727 $ — $ — $ 282,727 Certificates of Deposit 15,796 — — 15,796 Total assets at fair value: $ 298,523 $ — $ — $ 298,523 Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant other unobservable inputs (Level 3) Balance at December 31, 2018 Assets Money market funds $ 352,934 $ — $ — $ 352,934 Certificates of Deposit 15,501 — — 15,501 Total assets at fair value: $ 368,435 $ — $ — $ 368,435 |
Property and Equipment (Tables)
Property and Equipment (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Property Plant And Equipment [Abstract] | |
Schedule of Property and Equipment | Property and equipment consists of the following (in thousands): September 30, 2019 December 31, 2018 Computer equipment $ 326 $ 246 Laboratory equipment 817 611 Furniture and fixtures 1,052 293 Leasehold improvements 1,958 238 Construction in progress — 71 Accumulated depreciation (535 ) (322 ) Property and equipment, net $ 3,618 $ 1,137 |
Accrued expenses (Tables)
Accrued expenses (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Payables And Accruals [Abstract] | |
Schedule of Accrued Expenses | Accrued expenses are comprised as follows (in thousands): September 30, 2019 December 31, 2018 Accrued external research and professional fees $ 4,526 $ 1,591 Accrued external clinical study costs 6,755 4,692 Accrued compensation expense 2,233 2,693 Deferred rent, current portion — 9 Accrued expenses $ 13,514 $ 8,985 |
Leases (Tables)
Leases (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Leases [Abstract] | |
Summary of Lease Position and Weighted-Average Lease Term and Discount Rate of Operating Leases | The tables below reflect the Company’s lease position and weighted-average lease terms and discount rates for our operating leases as of September 30, 2019. Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, we use our incremental borrowing rate based on the information available at the lease commencement date. (in thousands) Classification on the Balance Sheet September 30, 2019 Assets Operating lease assets Operating lease assets $ 10,151 Total lease assets $ 10,151 Liabilities Current Operating Other current liabilities $ 472 Non-current Operating Operating lease liabilities 9,845 Total lease liabilities $ 10,317 |
Summary of Information Related to Lease Costs for Operating Leases | The table below presents information related to the lease costs for operating leases (in thousands): Three Months Ended September 30, Nine Months Ended September 30, (in thousands) Classification 2019 2018 2019 2018 Operating lease costs (a) Research and development $ 153 $ 75 $ 329 $ 211 General and administrative 92 26 145 53 Total operating lease costs $ 245 $ 101 $ 474 $ 264 (a) Includes variable lease costs which are immaterial |
Reconciliation of Undiscounted Cash Flow to Operating Lease Liabilities | The table below reconciles the undiscounted cash flow for each of the first five years and total of the remaining years to the operating lease liabilities recorded on the balance sheet as of September 30, 2019 (in thousands): Operating leases Years ending December 31, 2019 (excluding the nine months ended September 30, 2019) $ 299 2020 1,459 2021 2,015 2022 2,072 2023 1,634 Thereafter 6,534 Total future minimum lease payments $ 14,013 Less: present value adjustment (3,696 ) Total operating lease liabilities $ 10,317 |
Schedule of Minimum Future Rental Payments on Noncancelable Operating Leases | The following is a schedule by years of minimum future rental payments on noncancelable operating leases as of December 31, 2018 (in thousands): 2019 $ 680 2020 1,427 2021 1,960 2022 2,015 2023 1,577 2024 and thereafter 6,155 $ 13,814 |
Stockholders_ Equity (Tables)
Stockholders’ Equity (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Class Of Stock Disclosures [Abstract] | |
Summary of common stock shares reserved for future issuance | The Company has reserved for future issuance the following number of shares of common stock: September 30, 2019 December 31, 2018 Common stock options outstanding 5,762,159 4,502,133 Options available for grant under Equity Incentive Plans 950,697 1,547,306 6,712,856 6,049,439 |
Stock-based Compensation (Table
Stock-based Compensation (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Summary of Stock Option Activity | Stock option activity for the nine months ended September 30, 2019 is as follows: Weighted average Weighted average Remaining Aggregate Options exercise contractual intrinsic outstanding price life (Years) value (in thousands) Balance as of December 31, 2018 4,502,133 $ 14.13 7.6 $ 46,575 Cancelled (296,113 ) $ 19.96 Granted 1,895,525 22.05 Exercised (339,386 ) 6.83 Balance as of September 30, 2019 5,762,159 $ 16.87 7.7 $ 56,706 Exercisable at December 31, 2018 2,361,694 3.07 6.5 $ 38,285 Vested at December 31, 2018 and expected to vest 4,502,133 14.13 7.6 $ 46,575 Exercisable at September 30, 2019 2,813,106 7.90 6.3 $ 47,709 Vested at September 30, 2019 and expected to vest 5,762,159 16.87 7.7 $ 56,706 |
Employee and Non-employee Stock Options | |
Summary of Fair Value of Stock Options Granted Using Black-Scholes Options Pricing Model | The fair value of stock options was estimated using the following weighted-average assumptions for the three and nine months ended September 30, 2019 and September 30, 2018: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Expected volatility 74.4 - 77.1% 77.3 - 86.4% 74.2 - 82.1% 74.9 - 86.5% Weighted-average risk free rate 1.4 - 1.9% 2.7 - 2.9% 1.4 - 2.6% 2.3 - 2.9% Dividend yield —% —% —% —% Expected term (in years) 6.07 6.06 6.02 6.03 |
Summary of Stock-Based Compensation Expense Recognized in Statement of Operations by Classification | The table below summarizes the stock-based compensation expense recognized in the Company’s statement of operations by classification (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development $ 1,634 $ 1,473 $ 4,635 $ 3,900 General and administrative 2,807 1,803 7,351 3,071 Total stock-based compensation expense $ 4,441 $ 3,276 $ 11,986 $ 6,971 |
Net Loss Per Common Share (Tabl
Net Loss Per Common Share (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Earnings Per Share [Abstract] | |
Schedule of Potentially Dilutive Securities Excluded from Computations of Diluted Weighted-average Shares Outstanding | For the three months ended September 30, 2019 and 2018 and for the nine months ended September 30, 2019 and 2018 the following potentially dilutive securities have been excluded from the computations of diluted weighted-average shares outstanding because the effect would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) (unaudited) Stock options issued and outstanding 5,629,344 4,482,649 5,334,298 4,258,269 |
Business Description - Addition
Business Description - Additional Information (Details) | 9 Months Ended |
Sep. 30, 2019Product | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Number of clinical-stage product candidates from pipeline | 3 |
Basis of Presentation and Sum_4
Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) | 9 Months Ended | 12 Months Ended | |
Sep. 30, 2019 | Dec. 31, 2018 | Jan. 01, 2019 | |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||
Federal, state income tax benefit | $ 0 | ||
Unrecognized income tax benefits | 0 | $ 0 | |
Accrued income taxes | 0 | 0 | |
Operating loss carryforwards limitation | 8,000,000 | ||
Operating lease, asset | 10,151,000 | ||
Operating lease, liability | 10,317,000 | ||
ASU 2016-02 (Topic 842) | |||
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||
Operating lease, asset | $ 1,533,000 | ||
Operating lease, liability | $ 1,600,000 | ||
Federal | |||
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||
Operating loss carryforwards | 183,500,000 | $ 191,500,000 | |
Operating loss carryforwards expiration year | 2024 | ||
State | |||
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||
Operating loss carryforwards | $ 183,500,000 | $ 191,500,000 | |
Operating loss carryforwards expiration year | 2024 |
Basis of Presentation and Sum_5
Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Impact of Adoption of Topic 842 on Accompanying Balance Sheet (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Jan. 01, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||||||||
Operating lease assets | $ 10,151 | ||||||||
Accrued expenses | 13,514 | $ 8,985 | |||||||
Operating lease liabilities: | |||||||||
Other current liabilities | $ 472 | ||||||||
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherCurrentLiabilitiesMember | |||||||
Non-current operating lease liabilities | $ 9,845 | ||||||||
Other non-current liabilities | $ 88 | ||||||||
Stockholders' equity | $ 286,119 | $ 312,670 | $ 338,941 | $ 358,820 | $ 379,255 | $ 176,524 | $ 183,155 | $ 93,388 | |
ASU 2016-02 (Topic 842) | |||||||||
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||||||||
Operating lease assets | $ 1,533 | ||||||||
Accrued expenses | 8,976 | ||||||||
Operating lease liabilities: | |||||||||
Other current liabilities | $ 352 | ||||||||
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherCurrentLiabilitiesMember | ||||||||
Non-current operating lease liabilities | $ 1,278 | ||||||||
Stockholders' equity | 358,820 | ||||||||
ASU 2016-02 (Topic 842) | Adjustments Due to the Adoption of Topic 842 | |||||||||
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] | |||||||||
Operating lease assets | 1,533 | ||||||||
Accrued expenses | (9) | ||||||||
Operating lease liabilities: | |||||||||
Other current liabilities | $ 352 | ||||||||
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherCurrentLiabilitiesMember | ||||||||
Non-current operating lease liabilities | $ 1,278 | ||||||||
Other non-current liabilities | $ (88) |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Financial Instruments and Respective Fair Values (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Assets | ||
Assets at fair value | $ 298,523 | $ 368,435 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets | ||
Assets at fair value | 298,523 | 368,435 |
Money Market Funds | ||
Assets | ||
Assets at fair value | 282,727 | 352,934 |
Money Market Funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets | ||
Assets at fair value | 282,727 | 352,934 |
Certificates of Deposit | ||
Assets | ||
Assets at fair value | 15,796 | 15,501 |
Certificates of Deposit | Quoted Prices in Active Markets for Identical Assets (Level 1) | ||
Assets | ||
Assets at fair value | $ 15,796 | $ 15,501 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |
Sep. 30, 2019 | Sep. 30, 2019 | Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |||
Changes in valuation methodology | $ 0 | $ 0 | $ 0 |
Property and Equipment - Schedu
Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Property Plant And Equipment [Line Items] | ||
Accumulated depreciation | $ (535) | $ (322) |
Property and equipment, net | 3,618 | 1,137 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 326 | 246 |
Laboratory Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 817 | 611 |
Furniture and Fixtures | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 1,052 | 293 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 1,958 | 238 |
Construction in Progress | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 71 |
Property and Equipment - Additi
Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Property Plant And Equipment [Abstract] | ||||
Depreciation expenses relating to property and equipment | $ 86 | $ 48 | $ 215 | $ 115 |
Patent License Agreement - Addi
Patent License Agreement - Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 34 Months Ended | |||
Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2016 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | |
Patent License Agreement [Line Items] | ||||||
Non-refundable license issue fee | $ 22,941 | $ 15,873 | $ 64,510 | $ 51,605 | ||
University | ||||||
Patent License Agreement [Line Items] | ||||||
License agreement date | Nov. 23, 2016 | |||||
License agreement amendment date | Mar. 24, 2017 | |||||
Milestone payments | $ 500 | $ 600 | ||||
Term of license agreement description | The term of the license agreement will continue until the later of (i) the expiration of the last valid claim within the patent rights covering the product in such country, (ii) the expiration of market exclusivity in such country and (iii) the 10th anniversary of the first commercial sale in such country. The University may terminate the agreement in the event (i) the Company fails to pay any amount or make any report when required to be made and fails to cure such failure within thirty (30) days after receipt of notice from the University, (ii) is in breach of any provision of the agreement and fails to remedy such breach within forty-five (45) days after receipt of notice, (iii) makes a report to the University under the agreement that is determined to be materially false, (iv) declares insolvency or bankruptcy or (v) takes an action that causes patent rights or technical information to be subject to lien or encumbrance and fails to remedy any such breach with in forty-five (45) days of receipt of notice from the University. The Company may terminate the agreement at any time on written notice to the University at least ninety (90) days prior to the termination date specified in the notice. Upon expiration or termination of the agreement, all rights revert to the University. | |||||
License agreement termination notice period | 90 days | |||||
University | Maximum | ||||||
Patent License Agreement [Line Items] | ||||||
Milestone payments | $ 2,600 | |||||
University | License | ||||||
Patent License Agreement [Line Items] | ||||||
Non-refundable license issue fee | $ 500 |
Accrued Expenses - Schedule of
Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Payables And Accruals [Abstract] | ||
Accrued external research and professional fees | $ 4,526 | $ 1,591 |
Accrued external clinical study costs | 6,755 | 4,692 |
Accrued compensation expense | 2,233 | 2,693 |
Deferred rent, current portion | 9 | |
Accrued expenses | $ 13,514 | $ 8,985 |
Leases - Additional Information
Leases - Additional Information (Details) $ in Thousands | Jan. 27, 2016 | Jan. 10, 2014 | Nov. 30, 2018USD ($)ft² | Sep. 30, 2019USD ($) |
Operating Leased Assets [Line Items] | ||||
Lease expiration date | Dec. 31, 2022 | Jul. 31, 2017 | Sep. 30, 2027 | |
Renewal term | 5 years | 5 years | ||
Laboratory and office space lease to secure | ft² | 60,000 | |||
Lease commencement date | Sep. 2, 2019 | |||
Cash payments for measurement of operating leases | $ 389 | |||
Standby Letter of Credit | Restricted Cash | ||||
Operating Leased Assets [Line Items] | ||||
Security deposit | $ 500 |
Leases - Summary of Lease Posit
Leases - Summary of Lease Position and Weighted-Average Lease Term and Discount Rate of Operating Leases (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Assets | ||
Operating lease assets | $ 10,151 | |
Total lease assets | 10,151 | |
Liabilities | ||
Current operating lease liabilities | $ 472 | |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherCurrentLiabilitiesMember |
Non-current operating lease liabilities | $ 9,845 | |
Total lease liabilities | $ 10,317 | |
Weighted-average remaining lease term (years) | ||
Operating leases | 7 years 4 months 24 days | |
Weighted-average discount rate | ||
Operating leases | 7.70% |
Leases - Summary of Information
Leases - Summary of Information Related to Lease Costs for Operating Leases (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Operating Leased Assets [Line Items] | ||||
Total operating lease costs | $ 245 | $ 101 | $ 474 | $ 264 |
Research and Development | ||||
Operating Leased Assets [Line Items] | ||||
Operating lease costs | 153 | 75 | 329 | 211 |
General and Administrative | ||||
Operating Leased Assets [Line Items] | ||||
Operating lease costs | $ 92 | $ 26 | $ 145 | $ 53 |
Leases - Reconciliation of Undi
Leases - Reconciliation of Undiscounted Cash Flow to Operating Lease Liabilities (Details) $ in Thousands | Sep. 30, 2019USD ($) |
Leases [Abstract] | |
2019 (excluding the nine months ended September 30, 2019) | $ 299 |
2020 | 1,459 |
2021 | 2,015 |
2022 | 2,072 |
2023 | 1,634 |
Thereafter | 6,534 |
Total future minimum lease payments | 14,013 |
Less: present value adjustment | (3,696) |
Total operating lease liabilities | $ 10,317 |
Leases - Schedule of Minimum Fu
Leases - Schedule of Minimum Future Rental Payments on Noncancelable Operating Leases (Details) $ in Thousands | Dec. 31, 2018USD ($) |
Leases [Abstract] | |
2019 | $ 680 |
2020 | 1,427 |
2021 | 1,960 |
2022 | 2,015 |
2023 | 1,577 |
2024 and thereafter | 6,155 |
Total minimum future rentals | $ 13,814 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Details) - USD ($) | Sep. 21, 2018 | Jun. 30, 2018 | Jun. 15, 2018 | Mar. 12, 2018 | Aug. 02, 2018 | Aug. 02, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 |
Class Of Stock [Line Items] | |||||||||
Common stock, shares authorized | 120,000,000 | 120,000,000 | |||||||
Common stock, voting rights | Holders of common stock are entitled to one vote per share. | ||||||||
Proceeds from public offering, net of underwriting fees and commissions | $ 339,589,000 | ||||||||
Undesignated preferred stock, shares authorized to issue | 5,000,000 | ||||||||
Preferred stock, shares issued | 0 | ||||||||
Preferred stock, shares outstanding | 0 | ||||||||
Sales Agreement | Cowen and Company, LLC | |||||||||
Class Of Stock [Line Items] | |||||||||
Maximum gross proceeds of common stock allowed from issuance and sell | $ 125,000,000 | ||||||||
Net proceeds from issuance of common stock | $ 24,000,000 | $ 36,100,000 | |||||||
Sales Agreement | Cowen and Company, LLC | Common Stock | |||||||||
Class Of Stock [Line Items] | |||||||||
Common stock, shares issued | 752,008 | ||||||||
Sales Agreement | Cowen and Company, LLC | Common Stock | Weighted Average | |||||||||
Class Of Stock [Line Items] | |||||||||
Net proceeds from issuance of common stock | $ 12,100,000 | ||||||||
Underwritten Public Offering | |||||||||
Class Of Stock [Line Items] | |||||||||
Common stock, shares issued | 3,450,000 | 3,910,000 | |||||||
Common stock, price per share | $ 60 | $ 29.50 | |||||||
Gross proceeds from issuance of common stock | $ 207,000,000 | $ 115,300,000 | |||||||
Proceeds from public offering, net of underwriting fees and commissions | $ 194,900,000 | $ 107,900,000 | |||||||
Underwriters Option to Purchase | |||||||||
Class Of Stock [Line Items] | |||||||||
Common stock, shares issued | 450,000 | 510,000 |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of Common Stock Shares Reserved for Future Issuance (Details) - shares | Sep. 30, 2019 | Dec. 31, 2018 |
Class Of Stock [Line Items] | ||
Common stock, shares reserved for future issuance | 6,712,856 | 6,049,439 |
Common Stock Options Outstanding | ||
Class Of Stock [Line Items] | ||
Common stock, shares reserved for future issuance | 5,762,159 | 4,502,133 |
Options Available For Grant Under Equity Incentive Plan | ||
Class Of Stock [Line Items] | ||
Common stock, shares reserved for future issuance | 950,697 | 1,547,306 |
Stock-based Compensation - Addi
Stock-based Compensation - Additional Information (Details) - USD ($) | Jan. 01, 2019 | Jan. 01, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | May 31, 2017 |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Stock-based compensation | $ 11,986,000 | $ 6,971,000 | |||||
Employee Stock Options | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Stock options, maximum term | 10 years | ||||||
Stock-based compensation | $ 4,400,000 | $ 2,700,000 | $ 11,900,000 | 5,200,000 | |||
Non-employee Stock Options | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Stock-based compensation | $ 0 | $ 500,000 | $ 100,000 | $ 1,800,000 | |||
2017 Equity Incentive Plan | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Number of shares approved for grant under equity incentive plan | 1,932,000 | ||||||
Number of additional shares approved for grant under equity incentive plan | 1,096,553 | 1,066,692 | |||||
Number of shares available for grant under equity incentive plan | 950,697 | 950,697 | |||||
2011 Equity Incentive Plan | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Number of shares available for grant under equity incentive plan | 0 | 0 |
Stock-based Compensation - Fair
Stock-based Compensation - Fair Value of Stock Options Granted Using Black-Scholes Options Pricing Model (Details) - Employee and Non-employee Stock Options | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Expected volatility, minimum | 74.40% | 77.30% | 74.20% | 74.90% |
Expected volatility, maximum | 77.10% | 86.40% | 82.10% | 86.50% |
Weighted-average risk free rate, minimum | 1.40% | 2.70% | 1.40% | 2.30% |
Weighted-average risk free rate, maximum | 1.90% | 2.90% | 2.60% | 2.90% |
Expected term (in years) | 6 years 25 days | 6 years 21 days | 6 years 7 days | 6 years 10 days |
Stock-based Compensation - Summ
Stock-based Compensation - Summary of Stock-Based Compensation Expense Recognized in Statement of Operations by Classification (Details) - Employee and Non-employee Stock Options - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Total stock-based compensation expense | $ 4,441 | $ 3,276 | $ 11,986 | $ 6,971 |
Research and Development | ||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Total stock-based compensation expense | 1,634 | 1,473 | 4,635 | 3,900 |
General and Administrative | ||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Total stock-based compensation expense | $ 2,807 | $ 1,803 | $ 7,351 | $ 3,071 |
Stock-based Compensation - Su_2
Stock-based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands | 9 Months Ended | 12 Months Ended |
Sep. 30, 2019USD ($)$ / sharesshares | Dec. 31, 2018USD ($)$ / sharesshares | |
Options outstanding | ||
Beginning balance | shares | 4,502,133 | |
Cancelled | shares | (296,113) | |
Granted | shares | 1,895,525 | |
Exercised | shares | (339,386) | |
Ending balance | shares | 5,762,159 | 4,502,133 |
Exercisable | shares | 2,813,106 | 2,361,694 |
Vested and expected to vest | shares | 5,762,159 | 4,502,133 |
Weighted average exercise price | ||
Beginning balance | $ / shares | $ 14.13 | |
Cancelled | $ / shares | 19.96 | |
Granted | $ / shares | 22.05 | |
Exercised | $ / shares | 6.83 | |
Ending balance | $ / shares | 16.87 | $ 14.13 |
Exercisable | $ / shares | 7.90 | 3.07 |
Vested and expected to vest | $ / shares | $ 16.87 | $ 14.13 |
Weighted average, Remaining contractual for life (Years) | ||
Balance | 7 years 8 months 12 days | 7 years 7 months 6 days |
Exercisable | 6 years 3 months 18 days | 6 years 6 months |
Vested and expected to vest | 7 years 8 months 12 days | 7 years 7 months 6 days |
Weighted average, Aggregate intrinsic value | ||
Balance | $ | $ 56,706 | $ 46,575 |
Exercisable | $ | 47,709 | 38,285 |
Vested and expected to vest | $ | $ 56,706 | $ 46,575 |
Net Loss Per Common Share (Deta
Net Loss Per Common Share (Details) - shares | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Employee and Non-employee Stock Options | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Potentially dilutive securities excluded from computations of diluted weighted-average shares outstanding | 5,629,344 | 4,482,649 | 5,334,298 | 4,258,269 |
Related Party Transactions - Ad
Related Party Transactions - Additional Information (Details) | 9 Months Ended |
Sep. 30, 2019 | |
Scientific Advisory | Chairman of the Board of Directors | |
Related Party Transaction [Line Items] | |
Consulting agreements expiration date | Jun. 30, 2020 |