Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2018 | Nov. 05, 2018 | |
Document And Entity Information [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Sep. 30, 2018 | |
Document Fiscal Year Focus | 2,018 | |
Document Fiscal Period Focus | Q3 | |
Trading Symbol | KZR | |
Entity Registrant Name | Kezar Life Sciences, Inc. | |
Entity Central Index Key | 1,645,666 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Non-accelerated Filer | |
Entity Emerging Growth Company | true | |
Entity Small Business | false | |
Entity Ex Transition Period | true | |
Entity Common Stock, Shares Outstanding | 19,108,221 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Current assets: | ||
Cash and cash equivalents | $ 39,594 | $ 51,033 |
Marketable securities | 73,161 | |
Prepaid expenses | 1,676 | 785 |
Other current assets | 894 | 508 |
Total current assets | 115,325 | 52,326 |
Restricted cash | 13 | |
Property and equipment, net | 4,660 | 1,540 |
Other assets | 282 | 343 |
Total assets | 120,267 | 54,222 |
Current liabilities: | ||
Accounts payable | 662 | 547 |
Accrued liabilities | 2,345 | 911 |
Deferred rent, current | 343 | |
Other liabilities, current | 152 | 26 |
Total current liabilities | 3,502 | 1,484 |
Deferred rent, noncurrent | 2,638 | 494 |
Total liabilities | 6,140 | 1,978 |
Redeemable convertible preferred stock, $0.001 par value, zero and 75,533,240 shares authorized as of September 30, 2018 and December 31, 2017, respectively; zero and 12,263,126 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively | 77,931 | |
Stockholders' equity (deficit): | ||
Common stock, $0.001 par value, 125,000,000 and 96,000,000 shares authorized as of September 30, 2018 and December 31, 2017, respectively; 19,108,221 and 948,578 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively | 19 | 5 |
Preferred stock, $0.001 par value, 10,000,000 and zero shares authorized as of September 30, 2018 and December 31, 2017, respectively; zero shares issued and outstanding as of September 30, 2018 and December 31, 2017 | ||
Additional paid-in capital | 157,681 | 447 |
Accumulated other comprehensive loss | (160) | (111) |
Accumulated deficit | (43,413) | (26,028) |
Total stockholders' equity (deficit) | 114,127 | (25,687) |
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit) | $ 120,267 | $ 54,222 |
Condensed Consolidated Balanc_2
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2018 | Dec. 31, 2017 |
Statement Of Financial Position [Abstract] | ||
Redeemable convertible preferred stock, par value | $ 0.001 | $ 0.001 |
Redeemable convertible preferred stock, shares authorized | 0 | 75,533,240 |
Redeemable convertible preferred stock, shares issued | 0 | 12,263,126 |
Redeemable convertible preferred stock, shares outstanding | 0 | 12,263,126 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 125,000,000 | 96,000,000 |
Common stock, shares issued | 19,108,221 | 948,578 |
Common stock, shares outstanding | 19,108,221 | 948,578 |
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 10,000,000 | 0 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Condensed Consolidated Statemen
Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Operating expenses: | ||||
Research and development | $ 4,664 | $ 1,557 | $ 13,463 | $ 4,833 |
General and administrative | 1,600 | 635 | 4,837 | 1,497 |
Total operating expenses | 6,264 | 2,192 | 18,300 | 6,330 |
Loss from operations | (6,264) | (2,192) | (18,300) | (6,330) |
Interest income | 601 | 112 | 915 | 113 |
Net loss | $ (5,663) | $ (2,080) | $ (17,385) | $ (6,217) |
Net loss per common share, basic and diluted | $ (0.30) | $ (3.31) | $ (2.38) | $ (10.92) |
Weighted-average shares used to compute net loss per common share, basic and diluted | 18,955,384 | 628,435 | 7,319,012 | 569,417 |
Condensed Consolidated Statem_2
Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Statement Of Income And Comprehensive Income [Abstract] | ||||
Net loss | $ (5,663) | $ (2,080) | $ (17,385) | $ (6,217) |
Other comprehensive (loss) income, net of tax: | ||||
Foreign currency translation adjustments | (14) | (3) | (23) | 42 |
Unrealized loss on marketable securities | (26) | (26) | ||
Total other comprehensive (loss) income, net of tax | (40) | (3) | (49) | 42 |
Comprehensive loss | $ (5,703) | $ (2,083) | $ (17,434) | $ (6,175) |
Condensed Consolidated Statem_3
Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands | 9 Months Ended | |
Sep. 30, 2018 | Sep. 30, 2017 | |
Cash flows from operating activities: | ||
Net loss | $ (17,385) | $ (6,217) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Depreciation and amortization | 486 | 130 |
Stock-based compensation | 1,544 | 112 |
Amortization of premiums and discounts on marketable securities | (192) | |
Loss on disposal of property and equipment | 97 | |
Changes in operating assets and liabilities | ||
Prepaid expenses & other current assets | (1,333) | (965) |
Other assets | 61 | 1 |
Accounts payable & accrued liabilities | 1,628 | 443 |
Other liabilities, current | (9) | (2) |
Deferred rent | (216) | 5 |
Net cash used in operating activities | (15,319) | (6,493) |
Cash flows from investing activities: | ||
Purchases of property and equipment | (1,003) | (326) |
Purchases of marketable securities | (72,995) | |
Proceeds from sale of property and equipment | 10 | |
Net cash used in investing activities | (73,988) | (326) |
Cash flows from financing activities: | ||
Proceeds from issuance of common stock, net of issuance costs | 77,695 | |
Proceeds from issuance of preferred stock, net of issuance costs | 49,755 | |
Proceeds from the exercise of stock options | 213 | |
Net cash provided by financing activities | 77,908 | 49,755 |
Effect of exchange rate changes on cash and cash equivalents and restricted cash | (53) | 42 |
Net (decrease) increase in cash, cash equivalents and restricted cash | (11,452) | 42,978 |
Cash, cash equivalents and restricted cash at the beginning of period | 51,046 | 9,760 |
Cash, cash equivalents and restricted cash at the end of period | 39,594 | 52,738 |
Supplemental disclosures of noncash financing information: | ||
Reclassification of employee stock liability to equity upon vesting | 29 | $ 14 |
Addition of tenant improvement paid by landlord | 2,703 | |
Purchase of property and equipment in accounts payable | 7 | |
Conversion of redeemable convertible preferred stock into common stock | $ 77,931 |
Organization and Description of
Organization and Description of the Business | 9 Months Ended |
Sep. 30, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Organization and Description of the Business | 1. Organization and Description of the Business Description of Business Kezar Life Sciences, Inc. (the “Company”) was incorporated in Delaware on February 19, 2015, and commenced operations in June 2015. The Company is a clinical-stage biotechnology company, discovering and developing novel small molecule therapeutics to treat unmet needs in autoimmunity and cancer. The Company’s lead product candidate, KZR-616, a first-in-class selective immunoproteasome inhibitor, has completed testing in healthy volunteers and is now enrolling a Phase 1b/2 clinical trial in lupus and lupus nephritis. The Company is also leveraging its protein secretion pathway platform to discover and develop small molecule therapies targeting cancer and immuno-oncology. To date, the Company’s primary activities have been related to the establishment of its facilities, recruitment of personnel and conducting development of its product candidates, including clinical trials. The Company’s principal operations are in South San Francisco, California, and it operates in one segment. Reverse Stock Split On June 8, 2018, the Company filed an Amended and Restated Certificate of Incorporation effecting a 1-for-5.62 reverse stock split of its issued and outstanding shares of common stock and redeemable convertible preferred stock. The par value of the authorized stock was not adjusted as a result of the reverse stock split. In connection with the reverse stock split, the filed Amended and Restated Certificate of Incorporation also adjusted the minimum price per share required in a firm-commitment underwritten public offering of the Company’s common stock in order for the preferred stock to automatically convert to common stock. The minimum price post-split was $15.884 and was adjusted to $7.942. The Company did not adjust the number of authorized shares of common stock or redeemable convertible preferred stock. Other than the par value and the number of authorized shares of common stock, all share and per share data shown in the accompanying condensed consolidated financial statements and related notes have been retroactively revised to reflect the reverse stock split. Initial Public Offering On June 25, 2018, the Company completed its initial public offering (“IPO”), whereby the Company issued 5,750,000 shares of its common stock (inclusive of 750,000 shares of common stock pursuant to the full exercise of an overallotment option granted to the underwriters in connection with the offering) at a price of $15.00 per share. The shares began trading on The Nasdaq Global Select Market on June 21, 2018. The net proceeds received by the Company from the offering were approximately $77.7 million, after deducting underwriting discounts and commissions and other offering expenses payable by the Company of $8.6 million. Upon the closing of the IPO, all outstanding shares of redeemable convertible preferred stock converted into 12,263,126 shares of common stock. Additionally, the Company is now authorized to issue 125,000,000 shares of common stock and 10,000,000 shares of preferred stock. Liquidity Since commencing operations in mid-2015, substantially all of the Company’s efforts have been focused on research, development, and the advancement of the Company’s lead product candidate, KZR-616. The Company’s ultimate success depends on the outcome of the ongoing research and development activities. The Company has not yet generated product sales and as a result has experienced operating losses since inception and had an accumulated deficit of $43.4 million as of September 30, 2018. The Company expects to incur additional losses in the future to conduct research and development and will need to raise additional capital to fully implement management’s business plan. The Company intends to raise such capital through the issuance of additional equity, and potentially through borrowings, strategic alliances with partner companies and other licensing transactions. However, if such financing is not available at adequate levels, the Company may need to reevaluate its operating plans. Management believes that its existing cash, cash equivalents and marketable securities will be sufficient to fund the Company’s cash requirements for at least 12 months following the issuance of these financial statements. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2018 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2017 and the notes thereto, which are included in the Company’s prospectus that forms a part of the Company’s Registration Statement on Form S-1 (File No. 333-225194), which was filed with the Securities and Exchange Commission (“SEC”) pursuant to Rule 424 on June 21, 2018 (the “Prospectus”), and have had no material changes during the three and nine months ended September 30, 2018. Basis of Presentation and Consolidation The condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and include the Company’s accounts and those of its wholly owned Australian subsidiary, Unaudited Interim Condensed Consolidated Financial Statements The interim condensed consolidated balance sheet as of September 30, 2018, the condensed consolidated statements of operations and the condensed consolidated statements of comprehensive loss for the three and nine months ended September 30, 2017 and 2018, and the condensed consolidated statement of cash flows for the nine months ended September 30, 2017 and 2018 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair statement of the Company’s financial position as of September 30, 2018 and its results of operations for the three and nine months ended September 30, 2017 and 2018 and cash flows for the nine months ended September 30, 2017 and 2018. The financial data and the other financial information disclosed in these notes to the condensed consolidated financial statements related to the three and nine-month periods are also unaudited. The results of operations for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, or for any other future annual or interim period. The balance sheet as of December 31, 2017, included herein was derived from the audited consolidated financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements contained in the Company’s Prospectus. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant items subject to such estimates and assumptions include the useful lives of fixed assets, stock-based compensation, and accrued research and development costs. Management bases its estimates on historical experience and on various other market-specific relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates. Cash and Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less at the time of purchase to be cash equivalents. Cash equivalents consist of corporate debt securities and highly liquid money market funds. Restricted cash consisted of deposits at the bank held as collateral for the Company’s credit card program. The collateral requirement was removed and released in May 2018. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the same amounts shown in the consolidated statements of cash flows (in thousands): September 30, 2018 December 31, 2017 Cash and cash equivalents $ 39,594 $ 51,033 Restricted cash — 13 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 39,594 $ 51,046 Marketable Securities All marketable securities have been classified as “available-for-sale” in accordance with the Company’s investment policy and cash management strategy. Short-term marketable securities mature within one-year from the balance sheet date. Investments in marketable securities are recorded at fair value, with any unrealized gains and losses reported within accumulated other comprehensive income as a separate component of stockholders’ deficit until realized or until a determination is made that an other-than-temporary decline in market value has occurred. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion, together with interest on securities, are included in interest income on the Company’s condensed consolidated statements of operations. Accounting Pronouncements Adopted in 2018 In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting New Accounting Pronouncements Not Yet Adopted In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements The Company plans to adopt ASU 2016-02 on January 1, 2019 using the effective date approach as allowed under ASU 2018-11. In addition, the Company plans to apply the practical expedients provided by the FASB. expects that its recognition of expense on its statement of operations under ASU 2016-02 will be similar to its recognition of expense under the current accounting standard. Further, the Company expects to recognize lease liabilities and right-of use assets on its balance sheet. In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718) In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement |
Fair Value Measurements
Fair Value Measurements | 9 Months Ended |
Sep. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. Fair Value Measurements Financial assets and liabilities are recorded at fair value. The carrying amount of certain financial instruments, including cash and cash equivalents, restricted cash, accounts payable and accrued liabilities, approximate fair value due to their relatively short maturities. Assets and liabilities recorded at fair value on a recurring basis in the condensed consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1 : 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, quoted prices in markets that are not active, 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 : Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. We determine the fair value of Level 1 assets using quoted prices in active markets for identical assets. We review trading activity and pricing for Level 2 investments as of each measurement date. Level 2 inputs, which are obtained from various third-party data providers, represent quoted prices for similar assets in active markets and were derived from observable market data, or, if not directly observable, were derived from or corroborated by other observable market data. There were no transfers between Level 1 and Level 2 securities in the periods presented. In certain cases, where there is limited activity or less transparency around inputs to valuation, securities are classified as Level 3 within the valuation hierarchy. The Company does not have any assets or liabilities measured using Level 3 inputs as of September 30, 2018 or December 31, 2017. As of September 30, 2018 and December 31, 2017, financial assets and liabilities measured and recognized at fair value on a recurring basis and classified under the appropriate level of the fair value hierarchy as described above were as follows (in thousands): September 30, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Assets Level 1: Cash 691 — — 691 Money market funds 13,072 — — 13,072 U.S. Treasury securities 53,597 — (18 ) 53,579 Subtotal 67,360 — (18 ) 67,342 Level 2: Commercial paper 13,712 — (1 ) 13,711 Corporate debt securities 6,571 — (1 ) 6,570 Government agency bonds 25,137 — (5 ) 25,132 Subtotal 45,420 — (7 ) 45,413 Total $ 112,780 $ — $ (25 ) $ 112,755 Reported as: Cash and cash equivalents $ 39,594 Marketable securities $ 73,161 December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Assets Level 1: Cash 804 — — 804 Money market funds 50,229 — — 50,229 Restricted cash 13 — — 13 Subtotal 51,046 — — 51,046 Total $ 51,046 $ — $ — $ 51,046 Reported as: Cash and cash equivalents $ 51,033 Restricted cash $ 13 As of September 30, 2018, the amortized cost and estimated fair value of the Company’s available-for-sale securities by contractual maturity are shown below (in thousands): Amortized Estimated Cost Fair Value Marketable securities maturing: In one year or less $ 73,184 $ 73,161 Total marketable securities $ 73,184 $ 73,161 The Company determined that the gross unrealized losses on its marketable securities as of September 30, 2018 were temporary in nature. The Company currently does not intend to sell these securities prior to maturity and does not consider these investments to be other-than-temporarily impaired at September 30, 2018. |
Balance Sheet Components
Balance Sheet Components | 9 Months Ended |
Sep. 30, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Balance Sheet Components | 4. Balance Sheet Components Property and Equipment, Net Property and equipment consists of the following (in thousands): September 30, 2018 December 31, 2017 Leasehold improvements $ 3,268 $ 155 Furniture, laboratory and office equipment 1,984 1,242 Computer equipment 161 34 Construction in progress — 464 Total property and equipment 5,413 1,895 Less accumulated depreciation and amortization (753 ) (355 ) Property and equipment, net $ 4,660 $ 1,540 Under the terms of its lease for office and laboratory space at 4000 Shoreline Court, South San Francisco, the Company received an incentive from the landlord for $3.2 million to construct leasehold improvements, which have been recorded in fixed assets and as deferred rent in other liabilities that will be amortized over the remaining lease term. During the three and nine months ended September 30, 2018, the Company disposed of leasehold improvements, laboratory equipment and office equipment resulting in a loss of $0 and $97,000, respectively. There was no such loss during the three and nine months ended September 30, 2017. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): September 30, 2018 December 31, 2017 Accrued preclinical and research costs $ 1,075 $ 108 Accrued clinical costs 403 340 Accrued employee-related costs 722 422 Accrued professional services 74 — Other 71 41 Accrued liabilities $ 2,345 $ 911 |
Redeemable Convertible Preferre
Redeemable Convertible Preferred Stock | 9 Months Ended |
Sep. 30, 2018 | |
Temporary Equity Disclosure [Abstract] | |
Redeemable Convertible Preferred Stock | 5. Redeemable Convertible Preferred Stock Redeemable convertible preferred stock as of December 31, 2017 consisted of the following (in thousands, except share amounts): Redeemable Convertible Preferred Stock Shares Authorized Shares Issued and Outstanding Net Proceeds After Issuance Costs Liquidation Preference Series A 33,533,240 5,966,753 $ 28,176 $ 28,369 Series B 42,000,000 6,296,373 49,755 50,000 Total 75,533,240 12,263,126 $ 77,931 $ 78,369 In connection with the completion of the Company’s IPO in June 2018, all outstanding shares of convertible preferred stock converted into 12,263,126 shares of common stock. |
Stock-Based Compensation
Stock-Based Compensation | 9 Months Ended |
Sep. 30, 2018 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stock-Based Compensation | 6. Stock-Based Compensation Stock Incentive Plans 2018 Equity Incentive Plan In June 2018, the Company’s board of directors adopted and its stockholders approved the 2018 Equity Incentive Plan (the “2018 Plan”), which became effective as of June 20, 2018, at which point no further grants will be made under the 2015 Equity Incentive Plan (the “2015 Plan”) described below. Under the 2018 Plan, the Company may grant incentive stock options (“ISOs”), nonstatutory stock options (“NSOs”), stock appreciation rights, restricted stock awards, restricted stock units (“RSUs”) and other stock-based awards for the purchase of that number of shares of common stock. As of September 30, 2018, 75,621 shares of options and 10,189 RSUs have been granted and 1,812,145 shares were available for future issuance under the 2018 Plan. Initially, subject to adjustment as provided in the 2018 Plan, the aggregate number of shares of the Company’s common stock that may be issued pursuant to stock awards under the 2018 Plan will not exceed 4,000,000 shares, which is the sum of (i) 1,600,692 shares plus (ii) the number of shares reserved, and remaining available for issuance, under the 2015 Plan at the time the 2018 Plan became effective and (iii) the number of shares subject to stock options or other stock awards granted under the 2015 Plan that expire, terminate are forfeited or otherwise not issued, or are withheld to satisfy a tax withholding obligation in connection with an award or to satisfy a purchase or exercise price of an award (such as upon the expiration or termination of a stock award prior to vesting). The number of shares of the Company’s common stock reserved for issuance under the 2018 Plan will automatically increase on January 1 of each year, beginning on January 1, 2019 and continuing through and including January 1, 2028, by 5% of the total number of shares of capital stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares determined by the Company’s board of directors. The maximum number of shares that may be issued upon the exercise of ISOs under the 2018 Plan is 12,500,000 shares. 2015 Equity Incentive Plan The Company’s 2015 Equity Incentive Plan provided for the granting of ISOs and NSOs to employees, directors and consultants at the discretion of the board of directors. The 2015 Plan was terminated as to future awards in June 2018, although it continues to govern the terms of options that remain outstanding under the 2015 Plan. No additional stock awards will be granted under the 2015 Plan, and all outstanding stock awards granted under the 2015 Plan that are repurchased, forfeited, expire or are cancelled will become available for grant under the 2018 Plan in accordance with its terms. Options granted under the 2015 Plan expire no later than 10 years from the date of grant. Options granted under the 2015 Plan vest over periods determined by the board of directors, generally over four years. The 2015 Plan allows for early exercise of certain options prior to vesting. Upon termination of employment, the unvested shares are subject to repurchase at the original exercise price. As of September 30, 2018, options to purchase 2,102,045 shares of common stock were outstanding under the 2015 Plan. 2018 Employee Stock Purchase Plan In June 2018, the Company’s board of directors and its stockholders approved the 2018 Employee Stock Purchase Plan (the “ESPP”), which became effective as of June 20, 2018. The ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the U.S. Internal Revenue Code of 1986, as amended. The number of shares of common stock initially reserved for issuance under the ESPP was 200,000 shares. The ESPP provides for an annual increase on the first day of each year beginning in 2019 and ending in 2028, in each case subject to the approval of the board of directors, equal to the lesser of (i) 1% of the shares of common stock outstanding on the last day of the prior fiscal year or (ii) 375,000 shares; provided, that prior to the date of any such increase, the board of directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii). As of September 30, 2018, no shares of common stock had been issued under the ESPP and 200,000 shares remained available for future issuance under the ESPP. The option price per share of common stock to be paid by a participant upon exercise of the participant’s option on the applicable exercise date for an offering period shall be equal to 85% of the lesser of the fair market value of a share of common stock on (a) the applicable grant date or (b) the applicable exercise date. The Board authorized an initial offering beginning on November 16, 2018 and ending on May 15, 2019. Following the end of the initial offering, a new offering will automatically begin on the day that immediately follows the conclusion of the preceding offering. Stock Option Activity The following table summarizes activity under the Company’s stock option plan and related information (in thousands, except share and per share amounts): Number of Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at December 31, 2017 1,213,010 $ 1.54 8.7 $ 999 Options granted 1,111,901 $ 5.77 Options exercised (136,328 ) $ 1.56 $ 237 Options cancelled (10,917 ) $ 0.90 Outstanding at September 30, 2018 2,177,666 $ 3.70 8.7 $ 38,559 Vested and exercisable at September 30, 2018 747,477 $ 2.02 7.9 $ 14,493 The weighted average grant date fair value of options granted during the nine months ended September 30, 2018 was $4.12 per share. The 2015 Plan allows for early exercisable option grants, which permit the grantee to exercise a stock option in exchange for stock before the requisite service is provided (e.g., before the award is vested under its original terms); however, such arrangements permit the Company to subsequently repurchase such shares at the exercise price if the vesting conditions are not satisfied. To date, the Company has made such grants only to non-employee board members. The total intrinsic value of exercised stock options during the three and nine months ended September 30, 2018 was $0 and $237,000, respectively. The aggregate intrinsic value is calculated as the difference between the exercise price and the estimated fair value of the Company’s common stock at the date of exercise. Early Exercise Stock Purchase Agreements As of September 30, 2018 and December 31, 2017, there were 92,466 and 45,224, respectively, of nonvested common shares outstanding that were exercised early and subject to repurchase by the Company at the original issuance price upon termination of the stockholder’s services. The right to repurchase these shares generally lapses with respect to 25% of the shares underlying the option after the applicable vesting commencement date and 1/48 of the shares underlying the original grant per month for 36 months thereafter. The shares purchased pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be issued until those shares vest. The cash received in exchange for exercised and nonvested shares related to stock options granted is recorded as a liability for the early exercise of stock options on the balance sheets with the corresponding par value in common stock and an offset in additional paid-in capital. As of September 30, 2018 and December 31, 2017, the Company recorded in other current liabilities $152,000 and $18,000, respectively, associated with shares issued upon the early exercise of stock options that are subject to repurchase. Restricted Stock Units Granted to Employees There were no RSUs granted during the three months ended September 30, 2018. During the nine months ended September 30, 2018, the Company granted RSUs to certain employees to receive 10,189 shares of common stock pursuant to the 2018 Plan with a weighted-average estimated grant-date fair value of $17.75 per share. These RSUs were fully vested on the grant date. The valuation for these RSUs totaled $181,000 and was recognized as stock-based compensation expense in June 2018. There were no RSUs granted during the three and nine months ended September 30, 2017. Stock Options Granted to Employees That Contain Performance Condition There were no options granted that contained performance condition during the three months ended September 30, 2018. During nine months ended September 30, 2018, the Company granted options to two of its executive officers to purchase an aggregate 115,657 shares of common stock that vested fully upon the closing of the Company’s IPO on June 25, 2018. The aggregate fair value of these options was estimated at $474,000 and was recognized as stock-based compensation expense in June 2018. Restricted Stock In addition to the nonvested common shares outstanding described above at “Early Exercise Stock Purchase Agreements,” the Company issued restricted stock to its founders. The fair value of restricted stock on the issuance date is deemed equal to the cash consideration paid by the founders. Restricted stock vests over a four-year period from the applicable vesting commencement date. The following summarizes the activity of nonvested restricted stock: Number of Shares Nonvested—December 31, 2017 193,394 Vested (156,806 ) Nonvested—September 30, 2018 36,588 Stock-Based Compensation Expense Total stock-based compensation recognized by function was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 General and administrative $ 247 $ 19 $ 905 $ 60 Research and development 183 17 639 52 Total stock-based compensation expense $ 430 $ 36 $ 1,544 $ 112 As of September 30, 2018, the unrecognized stock-based compensation cost and the estimated weighted average amortization period, using the straight-line attribution method, was as follows (dollars in thousands): Unrecognized Compensation Cost Weighted Average Remaining Amortization Period (Years) Employee options $ 4,236 2.9 Nonemployee options 6 0.7 Total unrecognized stock-based compensation expense $ 4,242 The fair value of the employee stock options granted is calculated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Expected term (years) — — 5.5 - 6.1 6.1 Expected volatility — — 82.0 - 82.8% 82.5 % Risk-free interest rate — — 2.6 - 2.8% 2.1 % Expected dividend yield — — — — There were no stock options granted during the three months ended September 30, 2018 and 2017. |
Income Taxes
Income Taxes | 9 Months Ended |
Sep. 30, 2018 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 7. Income Taxes For the three and nine months ended September 30, 2018 and 2017, respectively, the Company did not record an income tax provision. The U.S. federal deferred tax assets generated from the Company’s net operating losses have been fully reserved, as the Company believes it is not more likely than not that the benefit will be realized. The Tax Cuts and Jobs Act of 2017 (the “Tax Act”) contains tax law changes that are effective in tax years 2018 and onward. The Company believes that these changes may alter the amount of tax loss generated, but does not believe that the changes will create a tax liability in 2018. In December 2015, the Protecting Americans from Tax Hikes (PATH) Act of 2015 was signed into law, which created several new research and development (“R&D”) tax credit provisions, including allowing qualified small businesses to utilize the R&D credit against the employer’s portion of payroll tax up to a maximum of $250,000 per year. The Company qualified as a small business under PATH for both 2016 and 2017. During the three and nine months ended September 30, 2018, the Company has utilized $152,000 of R&D tax credits as a reduction of research and development costs to offset its payroll tax liabilities. The remaining R&D tax credits available for future payroll tax liabilities have been recorded as deferred tax assets and a full valuation allowance. |
Net Loss per Share
Net Loss per Share | 9 Months Ended |
Sep. 30, 2018 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 8. Net Loss Per Share Net Loss Per Share The following table sets forth the calculation of basic and diluted net loss per share during the periods presented (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Numerator: Net loss $ (5,663 ) $ (2,080 ) $ (17,385 ) $ (6,217 ) Denominator: Weighted-average shares of common stock outstanding 18,955,384 628,435 7,319,012 569,417 Net loss per share, basic and diluted $ (0.30 ) $ (3.31 ) $ (2.38 ) $ (10.92 ) The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share for the periods presented because their effect would have been anti-dilutive: Three and Nine Months Ended September 30, 2018 2017 Redeemable convertible preferred stock on an if converted basis — 12,263,126 Stock options to purchase common stock 2,177,666 734,663 Common stock subject to future vesting 129,054 297,902 Total 2,306,720 13,295,691 |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
Sep. 30, 2018 | |
Accounting Policies [Abstract] | |
Basis of presentation and consolidation | Basis of Presentation and Consolidation The condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and include the Company’s accounts and those of its wholly owned Australian subsidiary, |
Unaudited Interim Condensed Consolidated Financial Statements | Unaudited Interim Condensed Consolidated Financial Statements The interim condensed consolidated balance sheet as of September 30, 2018, the condensed consolidated statements of operations and the condensed consolidated statements of comprehensive loss for the three and nine months ended September 30, 2017 and 2018, and the condensed consolidated statement of cash flows for the nine months ended September 30, 2017 and 2018 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair statement of the Company’s financial position as of September 30, 2018 and its results of operations for the three and nine months ended September 30, 2017 and 2018 and cash flows for the nine months ended September 30, 2017 and 2018. The financial data and the other financial information disclosed in these notes to the condensed consolidated financial statements related to the three and nine-month periods are also unaudited. The results of operations for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, or for any other future annual or interim period. The balance sheet as of December 31, 2017, included herein was derived from the audited consolidated financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements contained in the Company’s Prospectus. |
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 reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant items subject to such estimates and assumptions include the useful lives of fixed assets, stock-based compensation, and accrued research and development costs. Management bases its estimates on historical experience and on various other market-specific relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates. |
Cash and Cash Equivalents and Restricted Cash | Cash and Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less at the time of purchase to be cash equivalents. Cash equivalents consist of corporate debt securities and highly liquid money market funds. Restricted cash consisted of deposits at the bank held as collateral for the Company’s credit card program. The collateral requirement was removed and released in May 2018. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the same amounts shown in the consolidated statements of cash flows (in thousands): September 30, 2018 December 31, 2017 Cash and cash equivalents $ 39,594 $ 51,033 Restricted cash — 13 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 39,594 $ 51,046 |
Marketable Securities | Marketable Securities All marketable securities have been classified as “available-for-sale” in accordance with the Company’s investment policy and cash management strategy. Short-term marketable securities mature within one-year from the balance sheet date. Investments in marketable securities are recorded at fair value, with any unrealized gains and losses reported within accumulated other comprehensive income as a separate component of stockholders’ deficit until realized or until a determination is made that an other-than-temporary decline in market value has occurred. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion, together with interest on securities, are included in interest income on the Company’s condensed consolidated statements of operations. |
Accounting Pronouncements Adopted in 2018 and New Accounting Pronouncements Not Yet Adopted | Accounting Pronouncements Adopted in 2018 In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting New Accounting Pronouncements Not Yet Adopted In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements The Company plans to adopt ASU 2016-02 on January 1, 2019 using the effective date approach as allowed under ASU 2018-11. In addition, the Company plans to apply the practical expedients provided by the FASB. expects that its recognition of expense on its statement of operations under ASU 2016-02 will be similar to its recognition of expense under the current accounting standard. Further, the Company expects to recognize lease liabilities and right-of use assets on its balance sheet. In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718) In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Accounting Policies [Abstract] | |
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash | The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the same amounts shown in the consolidated statements of cash flows (in thousands): September 30, 2018 December 31, 2017 Cash and cash equivalents $ 39,594 $ 51,033 Restricted cash — 13 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 39,594 $ 51,046 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
Summary of Financial Assets and Liabilities Measured and Recognized at Fair Value on Recurring Basis | As of September 30, 2018 and December 31, 2017, financial assets and liabilities measured and recognized at fair value on a recurring basis and classified under the appropriate level of the fair value hierarchy as described above were as follows (in thousands): September 30, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Assets Level 1: Cash 691 — — 691 Money market funds 13,072 — — 13,072 U.S. Treasury securities 53,597 — (18 ) 53,579 Subtotal 67,360 — (18 ) 67,342 Level 2: Commercial paper 13,712 — (1 ) 13,711 Corporate debt securities 6,571 — (1 ) 6,570 Government agency bonds 25,137 — (5 ) 25,132 Subtotal 45,420 — (7 ) 45,413 Total $ 112,780 $ — $ (25 ) $ 112,755 Reported as: Cash and cash equivalents $ 39,594 Marketable securities $ 73,161 December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Assets Level 1: Cash 804 — — 804 Money market funds 50,229 — — 50,229 Restricted cash 13 — — 13 Subtotal 51,046 — — 51,046 Total $ 51,046 $ — $ — $ 51,046 Reported as: Cash and cash equivalents $ 51,033 Restricted cash $ 13 |
Summary of Amortized Cost and Estimated Fair Value of Available-for-sale Securities by Contractual Maturity | As of September 30, 2018, the amortized cost and estimated fair value of the Company’s available-for-sale securities by contractual maturity are shown below (in thousands): Amortized Estimated Cost Fair Value Marketable securities maturing: In one year or less $ 73,184 $ 73,161 Total marketable securities $ 73,184 $ 73,161 |
Balance Sheet Components (Table
Balance Sheet Components (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Property and Equipment | Property and equipment consists of the following (in thousands): September 30, 2018 December 31, 2017 Leasehold improvements $ 3,268 $ 155 Furniture, laboratory and office equipment 1,984 1,242 Computer equipment 161 34 Construction in progress — 464 Total property and equipment 5,413 1,895 Less accumulated depreciation and amortization (753 ) (355 ) Property and equipment, net $ 4,660 $ 1,540 |
Accrued Liabilities | Accrued liabilities consisted of the following (in thousands): September 30, 2018 December 31, 2017 Accrued preclinical and research costs $ 1,075 $ 108 Accrued clinical costs 403 340 Accrued employee-related costs 722 422 Accrued professional services 74 — Other 71 41 Accrued liabilities $ 2,345 $ 911 |
Redeemable Convertible Prefer_2
Redeemable Convertible Preferred Stock (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Temporary Equity Disclosure [Abstract] | |
Schedule of Redeemable Convertible Preferred Stock | Redeemable convertible preferred stock as of December 31, 2017 consisted of the following (in thousands, except share amounts): Redeemable Convertible Preferred Stock Shares Authorized Shares Issued and Outstanding Net Proceeds After Issuance Costs Liquidation Preference Series A 33,533,240 5,966,753 $ 28,176 $ 28,369 Series B 42,000,000 6,296,373 49,755 50,000 Total 75,533,240 12,263,126 $ 77,931 $ 78,369 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Activity under Stock Option Plan and Related Information | The following table summarizes activity under the Company’s stock option plan and related information (in thousands, except share and per share amounts): Number of Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at December 31, 2017 1,213,010 $ 1.54 8.7 $ 999 Options granted 1,111,901 $ 5.77 Options exercised (136,328 ) $ 1.56 $ 237 Options cancelled (10,917 ) $ 0.90 Outstanding at September 30, 2018 2,177,666 $ 3.70 8.7 $ 38,559 Vested and exercisable at September 30, 2018 747,477 $ 2.02 7.9 $ 14,493 |
Summarizes of Activity of Nonvested Restricted Stock | The following summarizes the activity of nonvested restricted stock: Number of Shares Nonvested—December 31, 2017 193,394 Vested (156,806 ) Nonvested—September 30, 2018 36,588 |
Stock-Based Compensation Recognized | Total stock-based compensation recognized by function was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 General and administrative $ 247 $ 19 $ 905 $ 60 Research and development 183 17 639 52 Total stock-based compensation expense $ 430 $ 36 $ 1,544 $ 112 |
Unrecognized Stock-based Compensation Cost and Estimated Weighted Average Amortization Period | As of September 30, 2018, the unrecognized stock-based compensation cost and the estimated weighted average amortization period, using the straight-line attribution method, was as follows (dollars in thousands): Unrecognized Compensation Cost Weighted Average Remaining Amortization Period (Years) Employee options $ 4,236 2.9 Nonemployee options 6 0.7 Total unrecognized stock-based compensation expense $ 4,242 |
Fair Value of Employee Stock Options Granted is Calculated Using Black Scholes Option Pricing Model with Weighted Average Assumptions | The fair value of the employee stock options granted is calculated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Expected term (years) — — 5.5 - 6.1 6.1 Expected volatility — — 82.0 - 82.8% 82.5 % Risk-free interest rate — — 2.6 - 2.8% 2.1 % Expected dividend yield — — — — |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Earnings Per Share [Abstract] | |
Calculation of Basic and Diluted Net Loss per Share | The following table sets forth the calculation of basic and diluted net loss per share during the periods presented (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Numerator: Net loss $ (5,663 ) $ (2,080 ) $ (17,385 ) $ (6,217 ) Denominator: Weighted-average shares of common stock outstanding 18,955,384 628,435 7,319,012 569,417 Net loss per share, basic and diluted $ (0.30 ) $ (3.31 ) $ (2.38 ) $ (10.92 ) |
Anti-dilutive Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share | The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share for the periods presented because their effect would have been anti-dilutive: Three and Nine Months Ended September 30, 2018 2017 Redeemable convertible preferred stock on an if converted basis — 12,263,126 Stock options to purchase common stock 2,177,666 734,663 Common stock subject to future vesting 129,054 297,902 Total 2,306,720 13,295,691 |
Organization and Description _2
Organization and Description of the Business - Additional Information (Details) $ / shares in Units, $ in Thousands | Jun. 25, 2018USD ($)$ / sharesshares | Jun. 08, 2018$ / shares | Sep. 30, 2018USD ($)Segmentshares | Dec. 31, 2017USD ($)shares |
Organization And Description Of Business [Line Items] | ||||
Number of operating segments | Segment | 1 | |||
Stockholders equity, reverse stock split | 1-for-5.62 | |||
Stockholders equity, stock split, conversion ratio | 0.1779 | |||
Minimum price post-split | $ / shares | $ 15.884 | |||
Adjusted price post split | $ / shares | $ 7.942 | |||
Net proceeds from issuance of common stock | $ | $ 77,695 | |||
Common stock, shares authorized | 125,000,000 | 96,000,000 | ||
Preferred stock, shares authorized | 10,000,000 | 0 | ||
Accumulated deficit | $ | $ 43,413 | $ 26,028 | ||
Minimum | ||||
Organization And Description Of Business [Line Items] | ||||
Sufficient cash and cash equivalents available period term | 12 months | |||
IPO | ||||
Organization And Description Of Business [Line Items] | ||||
Common stock, shares, issued | 5,750,000 | |||
Common stock, shares issued, price per share | $ / shares | $ 15 | |||
Net proceeds from issuance of common stock | $ | $ 77,700 | |||
Payments of stock issuance costs | $ | $ 8,600 | |||
Convertible preferred stock converted into common stock | 12,263,126 | |||
Common stock, shares authorized | 125,000,000 | |||
Preferred stock, shares authorized | 10,000,000 | |||
Overallotment Option | ||||
Organization And Description Of Business [Line Items] | ||||
Common stock, shares, issued | 750,000 |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Dec. 31, 2016 |
Accounting Policies [Abstract] | ||||
Cash and cash equivalents | $ 39,594 | $ 51,033 | ||
Restricted cash | 13 | |||
Total cash, cash equivalents and restricted cash shown in the statements of cash flows | $ 39,594 | $ 51,046 | $ 52,738 | $ 9,760 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Detail) | Sep. 30, 2018USD ($) |
Fair Value Disclosures [Abstract] | |
Transfers from Level 1 to Level 2 | $ 0 |
Transfers from Level 2 to Level 1 | $ 0 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Financial Assets and Liabilities Measured and Recognized at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | $ 73,184 | |
Fair Value | 73,161 | |
Fair Value, Measurements, Recurring | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 112,780 | $ 51,046 |
Unrealized Losses | (25) | |
Fair Value | 112,755 | 51,046 |
Cash and cash equivalents | 39,594 | 51,033 |
Marketable securities | 73,161 | |
Restricted cash | 13 | |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 67,360 | 51,046 |
Unrealized Losses | (18) | |
Fair Value | 67,342 | 51,046 |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Cash | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 691 | 804 |
Fair Value | 691 | 804 |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Money Market Funds | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 13,072 | 50,229 |
Fair Value | 13,072 | 50,229 |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | U.S. Treasury Securities | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 53,597 | |
Unrealized Losses | (18) | |
Fair Value | 53,579 | |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Restricted Cash | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 13 | |
Fair Value | $ 13 | |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 45,420 | |
Unrealized Losses | (7) | |
Fair Value | 45,413 | |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Commercial paper | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 13,712 | |
Unrealized Losses | (1) | |
Fair Value | 13,711 | |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Corporate Debt Securities | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 6,571 | |
Unrealized Losses | (1) | |
Fair Value | 6,570 | |
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Government agency bonds | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 25,137 | |
Unrealized Losses | (5) | |
Fair Value | $ 25,132 |
Fair Value Measurements - Sum_2
Fair Value Measurements - Summary of Amortized Cost and Estimated Fair Value of Available-for-sale Securities by Contractual Maturity (Details) $ in Thousands | Sep. 30, 2018USD ($) |
Marketable securities maturing, Amortized Cost: | |
In one year or less, Amortized Cost | $ 73,184 |
Total marketable securities, Amortized Cost | 73,184 |
Marketable securities maturing, Estimated Fair Value: | |
In one year or less, Estimated Fair Value | 73,161 |
Total marketable securities, Estimated Fair Value | $ 73,161 |
Balance Sheet Components - Prop
Balance Sheet Components - Property and Equipment (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Property Plant And Equipment [Line Items] | ||
Total property and equipment | $ 5,413 | $ 1,895 |
Less accumulated depreciation and amortization | (753) | (355) |
Property and equipment, net | 4,660 | 1,540 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | 3,268 | 155 |
Furniture, Laboratory and Office Equipment | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | 1,984 | 1,242 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | $ 161 | 34 |
Construction in Progress | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | $ 464 |
Balance Sheet Components - Addi
Balance Sheet Components - Additional Information (Details) - USD ($) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Property Plant And Equipment [Line Items] | ||||
Loss on disposal of property and equipment | $ 97,000 | |||
Leasehold Improvements | ||||
Property Plant And Equipment [Line Items] | ||||
Incentive received from landlord to construct leasehold improvements | 3,200,000 | |||
Leasehold Improvements, Laboratory Equipment and Office Equipment | ||||
Property Plant And Equipment [Line Items] | ||||
Loss on disposal of property and equipment | $ 0 | $ 0 | $ 97,000 | $ 0 |
Balance Sheet Components - Accr
Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | ||
Accrued preclinical and research costs | $ 1,075 | $ 108 |
Accrued clinical costs | 403 | 340 |
Accrued employee-related costs | 722 | 422 |
Accrued professional services | 74 | |
Other | 71 | 41 |
Accrued liabilities | $ 2,345 | $ 911 |
Redeemable Convertible Prefer_3
Redeemable Convertible Preferred Stock - Schedule of Redeemable Convertible Preferred Stock (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Temporary Equity [Line Items] | ||
Redeemable convertible preferred stock, shares authorized | 0 | 75,533,240 |
Shares Issued and Outstanding | 12,263,126 | |
Net Proceeds After Issuance Costs | $ 77,931 | |
Liquidation Preference | $ 78,369 | |
Series A | ||
Temporary Equity [Line Items] | ||
Redeemable convertible preferred stock, shares authorized | 33,533,240 | |
Shares Issued and Outstanding | 5,966,753 | |
Net Proceeds After Issuance Costs | $ 28,176 | |
Liquidation Preference | $ 28,369 | |
Series B | ||
Temporary Equity [Line Items] | ||
Redeemable convertible preferred stock, shares authorized | 42,000,000 | |
Shares Issued and Outstanding | 6,296,373 | |
Net Proceeds After Issuance Costs | $ 49,755 | |
Liquidation Preference | $ 50,000 |
Redeemable Convertible Prefer_4
Redeemable Convertible Preferred Stock - Additional Information (Details) | 1 Months Ended |
Jun. 30, 2018shares | |
IPO | |
Temporary Equity [Line Items] | |
Number of outstanding shares of convertible preferred stock converted into common stock | 12,263,126 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Details) | Jun. 25, 2018shares | Sep. 30, 2018USD ($)shares | Sep. 30, 2017USD ($)shares | Sep. 30, 2018USD ($)ExecutiveOfficer$ / sharesshares | Sep. 30, 2017USD ($)shares | Dec. 31, 2017USD ($)shares |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of options granted | 1,111,901 | |||||
Maximum number of shares issued upon exercise of incentive stock options | 747,477 | 747,477 | ||||
Common stock, shares issued | 19,108,221 | 19,108,221 | 948,578 | |||
Weighted average grant date fair value of options granted | $ / shares | $ 5.77 | |||||
Total intrinsic value of exercised stock options | $ | $ 237,000 | |||||
Stock-based compensation expense recognized | $ | $ 430,000 | $ 36,000 | $ 1,544,000 | $ 112,000 | ||
Stock options granted | $ | $ 0 | $ 0 | ||||
Early Exercise Stock Purchase Agreements | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Vesting period | 36 months | |||||
Nonvested common shares outstanding | 92,466 | 92,466 | 45,224 | |||
Percentage of underlying option shares whose right to purchase lapses after applicable vesting commencement date | 25.00% | |||||
Right to repurchase shares underlying shares | 0.0208 | |||||
Other Current Liabilities | Early Exercise Stock Purchase Agreements | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares issued upon early exercise of stock options are subject to repurchase | $ | $ 152,000 | $ 152,000 | $ 18,000 | |||
Stock Options Granted to Employees that Contain Performance Condition | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of options granted | 0 | 115,657 | ||||
Stock-based compensation expense recognized | $ | $ 474,000 | |||||
Number of executive officers granted with purchase option | ExecutiveOfficer | 2 | |||||
Number of option vested | 115,657 | |||||
Options vesting date | Jun. 25, 2018 | |||||
Stock-based compensation expense recognition period | 2018-06 | |||||
Restricted Stock | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Vesting period | 4 years | |||||
Nonvested common shares outstanding | 36,588 | 36,588 | 193,394 | |||
2018 Equity Incentive Plan | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares available for future issuance | 1,812,145 | 1,812,145 | ||||
Number of shares will increase automatically through every year on specified date | --01-01 | |||||
Number of shares increase automatically continuing through maximum period | beginning on January 1, 2019 and continuing through and including January 1, 2028 | |||||
2018 Equity Incentive Plan | Common Stock | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Maximum number of shares available for issuance | 1,600,692 | 1,600,692 | ||||
Increase in number of shares reserved for issuance as percentage of total number of shares of capital stock outstanding on last date of preceding calendar year | 5.00% | |||||
2018 Equity Incentive Plan | Maximum [Member] | Common Stock | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Maximum number of shares available for issuance | 4,000,000 | 4,000,000 | ||||
2018 Equity Incentive Plan | Employee options | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of options granted | 75,621 | |||||
2018 Equity Incentive Plan | Restricted Stock Units | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of RSU granted | 0 | 0 | 10,189 | 0 | ||
Weighted-average estimated grant-date fair value | $ / shares | $ 17.75 | |||||
Stock-based compensation expense recognized | $ | $ 181,000 | |||||
2018 Equity Incentive Plan | Incentive Stock Options | Maximum [Member] | Common Stock | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Maximum number of shares issued upon exercise of incentive stock options | 12,500,000 | 12,500,000 | ||||
2015 Equity Incentive Plan | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Vesting period | 4 years | |||||
Options to purchase of common stock outstanding | 2,102,045 | 2,102,045 | ||||
Weighted average grant date fair value of options granted | $ / shares | $ 4.12 | |||||
Total intrinsic value of exercised stock options | $ | $ 0 | $ 237,000 | ||||
2015 Equity Incentive Plan | Maximum [Member] | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Options granted expiry period | 10 years | |||||
2018 Employee Stock Purchase Plan | Common Stock | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares available for future issuance | 200,000 | 200,000 | ||||
Common stock, shares issued | 0 | 0 | ||||
Authorized an offering beginning period | Nov. 16, 2018 | |||||
Authorized an offering ending period | May 15, 2019 | |||||
2018 Employee Stock Purchase Plan | Maximum [Member] | Common Stock | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Percentage of annual increase in number of common stock shares | 1.00% | |||||
Annual increase in number of common stock shares | 375,000 | |||||
Option price per share of common stock at fair market value | 85.00% |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Activity under Stock Option Plan and Related Information (Details) $ / shares in Units, $ in Thousands | 9 Months Ended | 12 Months Ended |
Sep. 30, 2018USD ($)$ / sharesshares | Dec. 31, 2017USD ($)$ / sharesshares | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
Number of options outstanding, Outstanding, Beginning balance | shares | 1,213,010 | |
Number of options outstanding, Options granted | shares | 1,111,901 | |
Number of options outstanding, Options exercised | shares | (136,328) | |
Number of options outstanding, Options cancelled | shares | (10,917) | |
Number of options outstanding, Outstanding, Ending balance | shares | 2,177,666 | 1,213,010 |
Number of options outstanding, options vested and exercisable | shares | 747,477 | |
Weighted average exercise price, Outstanding, Beginning balance | $ / shares | $ 1.54 | |
Weighted average exercise price, Options granted | $ / shares | 5.77 | |
Weighted average exercise price, Options exercised | $ / shares | 1.56 | |
Weighted average exercise price, Options cancelled | $ / shares | 0.90 | |
Weighted average exercise price, Outstanding, Ending balance | $ / shares | 3.70 | $ 1.54 |
Weighted average exercise price, options vested and exercisable | $ / shares | $ 2.02 | |
Weighted average remaining contractual term, Outstanding, Beginning balance | 8 years 8 months 12 days | 8 years 8 months 12 days |
Weighted average remaining contractual term,options vested and exercisable | 7 years 10 months 24 days | |
Aggregate intrinsic value, Outstanding, Beginning balance | $ | $ 999 | |
Aggregate intrinsic value, Options exercised | $ | 237 | |
Aggregate intrinsic value, Outstanding, Ending balance | $ | 38,559 | $ 999 |
Aggregate intrinsic value, options vested and exercisable | $ | $ 14,493 |
Stock-Based Compensation - Su_2
Stock-Based Compensation - Summarizes of Activity of Nonvested Restricted Stock (Details) - Restricted Stock | 9 Months Ended |
Sep. 30, 2018shares | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Nonvested beginning balance | 193,394 |
Number of Shares Outstanding, Vested | (156,806) |
Nonvested ending balance | 36,588 |
Stock-Based Compensation - Stoc
Stock-Based Compensation - Stock-Based Compensation Recognized (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation expense | $ 430 | $ 36 | $ 1,544 | $ 112 |
Research and Development Expense | ||||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation expense | 247 | 19 | 905 | 60 |
General and Administrative Expense | ||||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation expense | $ 183 | $ 17 | $ 639 | $ 52 |
Stock-Based Compensation - Unre
Stock-Based Compensation - Unrecognized Stock-based Compensation Cost and Estimated Weighted Average Amortization Period (Details) $ in Thousands | 9 Months Ended |
Sep. 30, 2018USD ($) | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |
Unrecognized compensation cost | $ 4,242 |
Employee options | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |
Unrecognized compensation cost | $ 4,236 |
Weighted average remaining amortization period (years) | 2 years 10 months 24 days |
Nonemployee options | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |
Unrecognized costs of unvested options awarded | $ 6 |
Weighted average remaining amortization period (years) | 8 months 12 days |
Stock-Based Compensation - Fair
Stock-Based Compensation - Fair Value of Employee Stock Options Granted is Calculated Using Black Scholes Option Pricing Model with Weighted Average Assumptions (Details) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Expected term (years) | 6 years 1 month 6 days | 6 years 1 month 6 days | ||
Expected volatility | 82.50% | |||
Expected volatility, Minimum | 82.00% | |||
Expected volatility, Maximum | 82.80% | |||
Risk-free interest rate | 2.10% | |||
Risk-free interest rate, Minimum | 2.60% | |||
Risk-free interest rate, Maximum | 2.80% | |||
Minimum | ||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Expected term (years) | 5 years 6 months | 5 years 6 months | ||
Maximum [Member] | ||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||
Expected term (years) | 6 years 1 month 6 days | 6 years 1 month 6 days |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Details) - USD ($) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Income Tax Disclosure [Abstract] | ||||
Income tax provision | $ 0 | $ 0 | $ 0 | $ 0 |
Research and development tax credit utilized as reduction of research and development costs | $ 152,000 | $ 152,000 |
Net Loss Per Share - Calculatio
Net Loss Per Share - Calculation of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Numerator: | ||||
Net loss | $ (5,663) | $ (2,080) | $ (17,385) | $ (6,217) |
Denominator: | ||||
Weighted-average shares of common stock outstanding | 18,955,384 | 628,435 | 7,319,012 | 569,417 |
Net loss per common share, basic and diluted | $ (0.30) | $ (3.31) | $ (2.38) | $ (10.92) |
Net Loss Per Share - Anti-dilut
Net Loss Per Share - Anti-dilutive Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Details) - shares | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities excluded from computation of diluted net loss per share | 2,306,720 | 13,295,691 | 2,306,720 | 13,295,691 |
Redeemable Convertible Preferred Stock on an if Converted Basis | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities excluded from computation of diluted net loss per share | 12,263,126 | 12,263,126 | ||
Stock Options to Purchase Common Stock | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities excluded from computation of diluted net loss per share | 2,177,666 | 734,663 | 2,177,666 | 734,663 |
Common stock subject to future vesting [Member] | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Anti-dilutive securities excluded from computation of diluted net loss per share | 129,054 | 297,902 | 129,054 | 297,902 |