Document and Entity Information
Document and Entity Information - shares | 6 Months Ended | |
Jun. 30, 2018 | Aug. 08, 2018 | |
Document And Entity Information [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Jun. 30, 2018 | |
Document Fiscal Year Focus | 2,018 | |
Document Fiscal Period Focus | Q2 | |
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 Common Stock, Shares Outstanding | 19,108,221 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Current assets: | ||
Cash and cash equivalents | $ 101,973 | $ 51,033 |
Marketable securities | 16,412 | |
Prepaid expenses | 1,538 | 785 |
Other current assets | 661 | 508 |
Total current assets | 120,584 | 52,326 |
Restricted cash | 13 | |
Property and equipment, net | 4,805 | 1,540 |
Other assets | 282 | 343 |
Total assets | 125,671 | 54,222 |
Current liabilities: | ||
Accounts payable | 1,105 | 547 |
Accrued liabilities | 2,007 | 911 |
Deferred rent, current | 332 | |
Other liabilities, current | 158 | 26 |
Total current liabilities | 3,602 | 1,484 |
Deferred rent, noncurrent | 2,728 | 494 |
Total liabilities | 6,330 | 1,978 |
Redeemable convertible preferred stock, $0.001 par value, zero and 75,533,240 shares authorized as of June 30, 2018 and December 31, 2017, respectively; zero and 12,263,126 shares issued and outstanding as of June 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 June 30, 2018 and December 31, 2017, respectively; 19,108,221 and 948,578 shares issued and outstanding as of June 30, 2018 and December 31, 2017, respectively | 19 | 5 |
Preferred stock, $0.001 par value, 10,000,000 and 0 shares authorized as of June 30, 2018 and December 31, 2017, respectively; zero shares issued and outstanding as of June 30, 2018 and December 31, 2017 | ||
Additional paid-in capital | 157,192 | 447 |
Accumulated other comprehensive loss | (120) | (111) |
Accumulated deficit | (37,750) | (26,028) |
Total stockholders' equity (deficit) | 119,341 | (25,687) |
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit) | $ 125,671 | $ 54,222 |
Condensed Consolidated Balance3
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Jun. 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 | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Operating expenses: | ||||
Research and development | $ 5,228 | $ 1,445 | $ 8,800 | $ 3,276 |
General and administrative | 1,722 | 436 | 3,236 | 862 |
Total operating expenses | 6,950 | 1,881 | 12,036 | 4,138 |
Loss from operations | (6,950) | (1,881) | (12,036) | (4,138) |
Interest income | 175 | 1 | 314 | 1 |
Net loss | $ (6,775) | $ (1,880) | $ (11,722) | $ (4,137) |
Net loss per common share, basic and diluted | $ (3.31) | $ (3.30) | $ (8.35) | $ (7.67) |
Weighted-average shares used to compute net loss per common share, basic and diluted | 2,044,027 | 569,364 | 1,404,392 | 539,419 |
Condensed Consolidated Stateme5
Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Statement Of Income And Comprehensive Income [Abstract] | ||||
Net loss | $ (6,775) | $ (1,880) | $ (11,722) | $ (4,137) |
Other comprehensive (loss) income, net of tax: | ||||
Foreign currency translation adjustments | 14 | 42 | (9) | 45 |
Total other comprehensive (loss) income, net of tax | 14 | 42 | (9) | 45 |
Comprehensive loss | $ (6,761) | $ (1,838) | $ (11,731) | $ (4,092) |
Condensed Consolidated Stateme6
Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands | 6 Months Ended | |
Jun. 30, 2018 | Jun. 30, 2017 | |
Cash flows from operating activities: | ||
Net loss | $ (11,722) | $ (4,137) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Depreciation and amortization | 281 | 87 |
Stock-based compensation | 1,114 | 76 |
Loss on disposal of property and equipment | 97 | |
Changes in operating assets and liabilities | ||
Prepaid expenses & other current assets | (949) | (715) |
Other assets | 61 | 1 |
Accounts payable & accrued liabilities | 548 | 370 |
Other liabilities, current | (8) | (2) |
Deferred rent | (137) | 5 |
Net cash used in operating activities | (10,715) | (4,315) |
Cash flows from investing activities: | ||
Purchases of property and equipment | (915) | |
Purchases of marketable securities | (16,412) | |
Proceeds from sale of property and equipment | 10 | |
Net cash used in investing activities | (17,317) | |
Cash flows from financing activities: | ||
Proceeds from issuance of common stock, net of issuance costs | 78,782 | |
Proceeds from issuance of preferred stock, net of issuance costs | 42,414 | |
Proceeds from the exercise of stock options | 213 | |
Net cash provided by financing activities | 78,995 | 42,414 |
Effect of exchange rate changes on cash and cash equivalents and restricted cash | (36) | 45 |
Net increase in cash, cash equivalents and restricted cash | 50,927 | 38,144 |
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 | 101,973 | 47,904 |
Supplemental disclosures of noncash financing information: | ||
Reclassification of employee stock liability to equity upon vesting | 24 | $ 12 |
Addition of tenant improvement paid by landlord | 2,703 | |
Purchase of property and equipment in accounts payable | 35 | |
Conversion of redeemable convertible preferred stock into common stock | 77,931 | |
Unpaid initial public offering costs | $ 1,141 |
Organization and Description of
Organization and Description of the Business | 6 Months Ended |
Jun. 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 $77.6 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 $37.8 million as of June 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 and cash equivalents 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 | 6 Months Ended |
Jun. 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”), have had no material changes during the three and six months ended June 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 June 30, 2018, and the condensed consolidated statements of operations, comprehensive loss, and cash flows for the three and six months ended June 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 June 30, 2018 and its results of operations for the three and six months ended June 30, 2017 and 2018 and cash flows for the six months ended June 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 six-month periods are also unaudited. The results of operations for the three and six months ended June 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): June 30, 2018 December 31, 2017 Cash and cash equivalents $ 101,973 $ 51,033 Restricted cash — 13 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 101,973 $ 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. Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, “Leases.” ASU 2016-02 increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosing key information about leasing arrangements. ASU 2016-02 is effective on January 1, 2019. Management does not expect the adoption of ASU 2016-02 to have a material effect on its business. The Company is currently evaluating the effect the update will have on its financial statements and related disclosures. In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718).” ASU 2018-07 simplifies the accounting for nonemployee share-based payment transactions. This ASU is effective for public entities for interim and annual reporting periods beginning after December 15, 2018. The Company has evaluated the potential impact of this guidance and does not believe that it will have a material impact on the Company’s financial statements. |
Fair Value Measurements
Fair Value Measurements | 6 Months Ended |
Jun. 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. Where quoted prices for identical securities are available in an active market, securities are classified as Level 1 of the valuation hierarchy, including cash held at overnight sweep accounts. The Company’s Level 2 valuations of marketable securities are generally derived from independent pricing services based upon quoted prices in active markets for similar securities, with prices adjusted for yield and number of days to maturity, or based on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets. 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 June 30, 2018 or December 31, 2017. As of June 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): June 30, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Assets Level 1: Cash 5,497 — — 5,497 Money market funds 89,793 — — 89,793 U.S. Treasury securities 16,414 — (2 ) 16,412 Subtotal 111,704 — (2 ) 111,702 Level 2: Corporate debt securities 6,682 1 — 6,683 Subtotal 6,682 1 — 6,683 Total $ 118,386 $ 1 $ (2 ) $ 118,385 Reported as: Cash and cash equivalents $ 101,973 Marketable securities $ 16,412 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 Where quoted prices are available in an active market, securities are classified as Level 1. The Company classifies money market funds as Level 1. When quoted market prices are not available for the specific security, then the Company estimates fair value by using benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. There were no transfers between Level 1 and Level 2 during the periods presented. As of June 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 $ 16,414 $ 16,412 Total marketable securities $ 16,414 $ 16,412 The Company determined that the gross unrealized losses on its marketable securities as of June 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 June 30, 2018. There were no sales of available-for-sale securities in any of the periods presented. |
Balance Sheet Components
Balance Sheet Components | 6 Months Ended |
Jun. 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): June 30, 2018 December 31, 2017 Leasehold improvements $ 3,255 $ 155 Furniture, laboratory and office equipment 1,978 1,242 Computer equipment 120 34 Construction in progress — 464 Total property and equipment 5,353 1,895 Less accumulated depreciation and amortization (548 ) (355 ) Property and equipment, net $ 4,805 $ 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 six months ended June 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 six months ended June 30, 2017. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): June 30, 2018 December 31, 2017 Accrued preclinical and research costs $ 546 $ 108 Accrued clinical costs 64 340 Accrued employee-related costs 688 422 Accrued professional services 635 — Other 74 41 Accrued liabilities $ 2,007 $ 911 |
Redeemable Convertible Preferre
Redeemable Convertible Preferred Stock | 6 Months Ended |
Jun. 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 | 6 Months Ended |
Jun. 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 June 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. The maximum number of shares of common stock subject to stock awards granted under the 2018 Plan or otherwise during any one calendar year to any non-employee director, taken together with any cash fees paid by the Company to such non-employee director during such calendar year for service on the board of directors, will not exceed $750,000 in total value (calculating the value of any such stock awards based on the grant date fair value of such stock awards for financial reporting purposes), or, with respect to the calendar year in which a non-employee director is first appointed or elected to the Company’s board of directors, $1,100,000. 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 Company granted options under its 2015 Plan until April 2018 and it 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. After the effective date of the 2018 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 June 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 June 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 first offering period has not yet been decided by the Company’s board of directors. 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 Additional shares authorized Options granted 1,111,901 $ 5.77 Options exercised (136,328 ) $ 1.56 $ 237 Options cancelled (10,917 ) $ 0.90 Outstanding at June 30, 2018 2,177,666 $ 3.70 9.0 $ 29,609 Options exercisable at June 30, 2018 535,218 $ 1.46 7.8 $ 8,478 The weighted average grant date fair value of options granted during the six months ended June 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 six months ended June 30, 2018 was $133,000 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 June 30, 2018 and December 31, 2017, there were 101,823 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 June 30, 2018 and December 31, 2017, the Company recorded in other current liabilities $158,000 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 During the three and six months ended June 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 six months ended June 30, 2017. Number of RSUs Outstanding Weighted Average Grant-Date Fair Price Outstanding at December 31, 2017 — RSUs granted 10,189 $ 17.75 RSUs vested (10,189 ) $ 17.75 Outstanding at June 30, 2018 — Stock Options Granted to Employees That Contain Performance Condition During the three and six months ended June 30, 2018, the Company granted options to two of its executive officers to purchase an aggregate 115,657 shares of common stock that vest fully upon the achievement of the closing of the Company’s IPO. These options became fully vested 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 (104,537 ) Nonvested—June 30, 2018 88,857 Stock-Based Compensation Expense Total stock-based compensation recognized by function was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 General and administrative $ 558 $ 20 $ 625 $ 41 Research and development 430 18 489 35 Total stock-based compensation expense $ 988 $ 38 $ 1,114 $ 76 As of June 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 $ 4,664 3.5 Nonemployee options 7 1.0 Total unrecognized stock-based compensation expense $ 4,671 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 June 30, Six Months Ended June 30, 2018 2017 2018 2017 Expected term (years) 5.5 - 6.1 6.1 5.5 - 6.1 6.1 Expected volatility 82.8 % 82.5 % 82.0 - 82.8% 82.5 % Risk-free interest rate 2.8 % 2.1 % 2.6 - 2.8% 2.1 % Expected dividend yield — % — % — % — % |
Income Taxes
Income Taxes | 6 Months Ended |
Jun. 30, 2018 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 7. Income Taxes For the three and six months ended June 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. |
Net Loss per Share
Net Loss per Share | 6 Months Ended |
Jun. 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 June 30, Six Months Ended June 30, 2018 2017 2018 2017 Numerator: Net loss $ (6,775 ) $ (1,880 ) $ (11,722 ) $ (4,137 ) Denominator: Weighted-average shares of common stock outstanding 2,044,027 569,364 1,404,392 539,419 Net loss per share, basic and diluted $ (3.31 ) $ (3.30 ) $ (8.35 ) $ (7.67 ) 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 Six Months ended June 30, 2018 2017 Redeemable convertible preferred stock on an if converted basis — 11,334,414 Stock options to purchase common stock 2,177,666 734,663 Common stock subject to future vesting 190,680 357,190 Total 2,368,346 12,426,267 |
Related Party Disclosure
Related Party Disclosure | 6 Months Ended |
Jun. 30, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Disclosure | 9. Related Party Disclosure Consulting Agreement with Michael Kauffman On April 1, 2017, the Company entered into a consulting agreement with Michael Kauffman, a member of its board of directors. This agreement provides that Dr. Kauffman shall provide clinical and scientific advisory services and participate on the Company’s board of directors in exchange for a monthly fee of $3,000, payable on the first of the month. The consulting agreement terminated in June 2018 in connection with the Company’s IPO. For the three and six months ended June 30, 2018, the Company recognized $8,100 and $17,100, respectively as consulting expense for the agreement. For the three and six months ended June 30, 2017, the Company recognized $9,000 as consulting expense for the agreement. |
Summary of Significant Accoun16
Summary of Significant Accounting Policies (Policies) | 6 Months Ended |
Jun. 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 June 30, 2018, and the condensed consolidated statements of operations, comprehensive loss, and cash flows for the three and six months ended June 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 June 30, 2018 and its results of operations for the three and six months ended June 30, 2017 and 2018 and cash flows for the six months ended June 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 six-month periods are also unaudited. The results of operations for the three and six months ended June 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): June 30, 2018 December 31, 2017 Cash and cash equivalents $ 101,973 $ 51,033 Restricted cash — 13 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 101,973 $ 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. |
Recently Issued Accounting Pronouncements | Recently Issued Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, “Leases.” ASU 2016-02 increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosing key information about leasing arrangements. ASU 2016-02 is effective on January 1, 2019. Management does not expect the adoption of ASU 2016-02 to have a material effect on its business. The Company is currently evaluating the effect the update will have on its financial statements and related disclosures. In May 2017, the FASB issued ASU No. 2017-09, Compensation – Stock Compensation (Topic 718): Scope of Modification Accounting In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718).” ASU 2018-07 simplifies the accounting for nonemployee share-based payment transactions. This ASU is effective for public entities for interim and annual reporting periods beginning after December 15, 2018. The Company has evaluated the potential impact of this guidance and does not believe that it will have a material impact on the Company’s financial statements. |
Summary of Significant Accoun17
Summary of Significant Accounting Policies (Tables) | 6 Months Ended |
Jun. 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): June 30, 2018 December 31, 2017 Cash and cash equivalents $ 101,973 $ 51,033 Restricted cash — 13 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 101,973 $ 51,046 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
Summary of Financial Assets and Liabilities Measured and Recognized at Fair Value on Recurring Basis | As of June 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): June 30, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Assets Level 1: Cash 5,497 — — 5,497 Money market funds 89,793 — — 89,793 U.S. Treasury securities 16,414 — (2 ) 16,412 Subtotal 111,704 — (2 ) 111,702 Level 2: Corporate debt securities 6,682 1 — 6,683 Subtotal 6,682 1 — 6,683 Total $ 118,386 $ 1 $ (2 ) $ 118,385 Reported as: Cash and cash equivalents $ 101,973 Marketable securities $ 16,412 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 June 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 $ 16,414 $ 16,412 Total marketable securities $ 16,414 $ 16,412 |
Balance Sheet Components (Table
Balance Sheet Components (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Property and Equipment | Property and equipment consists of the following (in thousands): June 30, 2018 December 31, 2017 Leasehold improvements $ 3,255 $ 155 Furniture, laboratory and office equipment 1,978 1,242 Computer equipment 120 34 Construction in progress — 464 Total property and equipment 5,353 1,895 Less accumulated depreciation and amortization (548 ) (355 ) Property and equipment, net $ 4,805 $ 1,540 |
Accrued Liabilities | Accrued liabilities consisted of the following (in thousands): June 30, 2018 December 31, 2017 Accrued preclinical and research costs $ 546 $ 108 Accrued clinical costs 64 340 Accrued employee-related costs 688 422 Accrued professional services 635 — Other 74 41 Accrued liabilities $ 2,007 $ 911 |
Redeemable Convertible Prefer20
Redeemable Convertible Preferred Stock (Tables) | 6 Months Ended |
Jun. 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) | 6 Months Ended |
Jun. 30, 2018 | |
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 Additional shares authorized Options granted 1,111,901 $ 5.77 Options exercised (136,328 ) $ 1.56 $ 237 Options cancelled (10,917 ) $ 0.90 Outstanding at June 30, 2018 2,177,666 $ 3.70 9.0 $ 29,609 Options exercisable at June 30, 2018 535,218 $ 1.46 7.8 $ 8,478 |
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 (104,537 ) Nonvested—June 30, 2018 88,857 |
Stock-Based Compensation Recognized | Total stock-based compensation recognized by function was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 General and administrative $ 558 $ 20 $ 625 $ 41 Research and development 430 18 489 35 Total stock-based compensation expense $ 988 $ 38 $ 1,114 $ 76 |
Unrecognized Stock-based Compensation Cost and Estimated Weighted Average Amortization Period | As of June 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 $ 4,664 3.5 Nonemployee options 7 1.0 Total unrecognized stock-based compensation expense $ 4,671 |
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 June 30, Six Months Ended June 30, 2018 2017 2018 2017 Expected term (years) 5.5 - 6.1 6.1 5.5 - 6.1 6.1 Expected volatility 82.8 % 82.5 % 82.0 - 82.8% 82.5 % Risk-free interest rate 2.8 % 2.1 % 2.6 - 2.8% 2.1 % Expected dividend yield — % — % — % — % |
Restricted Stock Units | |
Summarizes of Activity of Nonvested Restricted Stock | During the three and six months ended June 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 six months ended June 30, 2017. Number of RSUs Outstanding Weighted Average Grant-Date Fair Price Outstanding at December 31, 2017 — RSUs granted 10,189 $ 17.75 RSUs vested (10,189 ) $ 17.75 Outstanding at June 30, 2018 — |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 6 Months Ended |
Jun. 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 June 30, Six Months Ended June 30, 2018 2017 2018 2017 Numerator: Net loss $ (6,775 ) $ (1,880 ) $ (11,722 ) $ (4,137 ) Denominator: Weighted-average shares of common stock outstanding 2,044,027 569,364 1,404,392 539,419 Net loss per share, basic and diluted $ (3.31 ) $ (3.30 ) $ (8.35 ) $ (7.67 ) |
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 Six Months ended June 30, 2018 2017 Redeemable convertible preferred stock on an if converted basis — 11,334,414 Stock options to purchase common stock 2,177,666 734,663 Common stock subject to future vesting 190,680 357,190 Total 2,368,346 12,426,267 |
Organization and Description 23
Organization and Description of the Business - Additional Information (Details) $ / shares in Units, $ in Thousands | Jun. 25, 2018USD ($)$ / sharesshares | Jun. 08, 2018$ / shares | Jun. 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 | $ | $ 78,782 | |||
Common stock, shares authorized | 125,000,000 | 96,000,000 | ||
Preferred stock, shares authorized | 10,000,000 | 0 | ||
Accumulated deficit | $ | $ 37,750 | $ 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 | $ | $ 77,600 | |||
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 Accoun24
Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 | Jun. 30, 2017 | Dec. 31, 2016 |
Accounting Policies [Abstract] | ||||
Cash and cash equivalents | $ 101,973 | $ 51,033 | ||
Restricted cash | 13 | |||
Total cash, cash equivalents and restricted cash shown in the statements of cash flows | $ 101,973 | $ 51,046 | $ 47,904 | $ 9,760 |
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 | Jun. 30, 2018 | Dec. 31, 2017 |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | $ 16,414 | |
Fair Value | 16,412 | |
Fair Value, Measurements, Recurring | ||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
Amortized Cost | 118,386 | $ 51,046 |
Unrealized Gains | 1 | |
Unrealized Losses | (2) | |
Fair Value | 118,385 | 51,046 |
Cash and cash equivalents | 101,973 | 51,033 |
Marketable securities | 16,412 | |
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 | 111,704 | 51,046 |
Unrealized Losses | (2) | |
Fair Value | 111,702 | 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 | 5,497 | 804 |
Fair Value | 5,497 | 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 | 89,793 | 50,229 |
Fair Value | 89,793 | 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 | 16,414 | |
Unrealized Losses | (2) | |
Fair Value | 16,412 | |
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 | 6,682 | |
Unrealized Gains | 1 | |
Fair Value | 6,683 | |
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 | 6,682 | |
Unrealized Gains | 1 | |
Fair Value | $ 6,683 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Details) | 6 Months Ended |
Jun. 30, 2018USD ($) | |
Fair Value Disclosures [Abstract] | |
Transfers from Level 1 to Level 2 | $ 0 |
Transfers from Level 2 to Level 1 | 0 |
Sale of available-for-sale securities | $ 0 |
Fair Value Measurements - Sum27
Fair Value Measurements - Summary of Amortized Cost and Estimated Fair Value of Available-for-sale Securities by Contractual Maturity (Details) $ in Thousands | Jun. 30, 2018USD ($) |
Marketable securities maturing, Amortized Cost: | |
In one year or less, Amortized Cost | $ 16,414 |
Total marketable securities, Amortized Cost | 16,414 |
Marketable securities maturing, Estimated Fair Value: | |
In one year or less, Estimated Fair Value | 16,412 |
Total marketable securities, Estimated Fair Value | $ 16,412 |
Balance Sheet Components - Prop
Balance Sheet Components - Property and Equipment (Details) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Property Plant And Equipment [Line Items] | ||
Total property and equipment | $ 5,353 | $ 1,895 |
Less accumulated depreciation and amortization | (548) | (355) |
Property and equipment, net | 4,805 | 1,540 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | 3,255 | 155 |
Furniture, Laboratory and Office Equipment | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | 1,978 | 1,242 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Total property and equipment | $ 120 | 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 | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 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 | Jun. 30, 2018 | Dec. 31, 2017 |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | ||
Accrued preclinical and research costs | $ 546 | $ 108 |
Accrued clinical costs | 64 | 340 |
Accrued employee-related costs | 688 | 422 |
Accrued professional services | 635 | |
Other | 74 | 41 |
Accrued liabilities | $ 2,007 | $ 911 |
Redeemable Convertible Prefer31
Redeemable Convertible Preferred Stock - Schedule of Redeemable Convertible Preferred Stock (Details) - USD ($) $ in Thousands | Jun. 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 Prefer32
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 | Jun. 30, 2018USD ($)ExecutiveOfficer$ / sharesshares | Jun. 30, 2017USD ($)shares | Jun. 30, 2018USD ($)ExecutiveOfficer$ / sharesshares | Jun. 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 | 535,218 | 535,218 | ||||
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 | $ | $ 988,000 | $ 38,000 | $ 1,114,000 | $ 76,000 | ||
Early Exercise Stock Purchase Agreements | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Vesting period | 36 months | |||||
Nonvested common shares outstanding | 101,823 | 101,823 | 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 | $ | $ 158,000 | $ 158,000 | $ 18,000 | |||
Restricted Stock Units | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of RSU granted | 10,189 | |||||
Weighted-average estimated grant-date fair value | $ / shares | $ 17.75 | |||||
Stock Options Granted to Employees that Contain Performance Condition | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of options granted | 115,657 | 115,657 | ||||
Stock-based compensation expense recognized | $ | $ 474,000 | $ 474,000 | ||||
Number of executive officers granted with purchase option | ExecutiveOfficer | 2 | 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 | 88,857 | 88,857 | 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 | Common Stock | Non-Employee Director | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Maximum value of common stock to be granted during any calendar year inclusive of service fees | $ | $ 750,000 | |||||
Maximum value of common stock to be granted during first year of appointment inclusive of service fees | $ | $ 1,100,000 | |||||
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 | 10,189 | 0 | 10,189 | 0 | ||
Weighted-average estimated grant-date fair value | $ / shares | $ 17.75 | $ 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 | $ | $ 133,000 | $ 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 | ||||
Common shares issued first offering period | 0 years | |||||
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 | 6 Months Ended | 12 Months Ended |
Jun. 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 exercisable | shares | 535,218 | |
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 exercisable | $ / shares | $ 1.46 | |
Weighted average remaining contractual term, Outstanding, Beginning balance | 9 years | 8 years 8 months 12 days |
Weighted average remaining contractual term,options exercisable | 7 years 9 months 18 days | |
Aggregate intrinsic value, Outstanding, Beginning balance | $ | $ 999 | |
Aggregate intrinsic value, Options exercised | $ | 237 | |
Aggregate intrinsic value, Outstanding, Ending balance | $ | 29,609 | $ 999 |
Aggregate intrinsic value, options exercisable | $ | $ 8,478 |
Stock-Based Compensation - Su35
Stock-Based Compensation - Summarizes of Activity of Nonvested Restricted Stock (Details) | 6 Months Ended |
Jun. 30, 2018$ / sharesshares | |
Restricted Stock Units | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of Shares, Outstanding, Granted | 10,189 |
Number of Shares Outstanding, Vested | (10,189) |
Weighted Average Grant-Date Fair Price, Granted | $ / shares | $ 17.75 |
Weighted Average Grant-Date Fair Price, Vested | $ / shares | $ 17.75 |
Restricted Stock | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of Shares, Outstanding, Beginning balance | 193,394 |
Number of Shares Outstanding, Vested | (104,537) |
Number of Shares Outstanding, Ending balance | 88,857 |
Stock-Based Compensation - Stoc
Stock-Based Compensation - Stock-Based Compensation Recognized (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation expense | $ 988 | $ 38 | $ 1,114 | $ 76 |
Research and Development Expense | ||||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation expense | 558 | 20 | 625 | 41 |
General and Administrative Expense | ||||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation expense | $ 430 | $ 18 | $ 489 | $ 35 |
Stock-Based Compensation - Unre
Stock-Based Compensation - Unrecognized Stock-based Compensation Cost and Estimated Weighted Average Amortization Period (Details) $ in Thousands | 6 Months Ended |
Jun. 30, 2018USD ($) | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |
Unrecognized compensation cost | $ 4,671 |
Employee options | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |
Unrecognized compensation cost | $ 4,664 |
Weighted average remaining amortization period (years) | 3 years 6 months |
Nonemployee options | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |
Unrecognized costs of unvested options awarded | $ 7 |
Weighted average remaining amortization period (years) | 1 year |
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 | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 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 | 82.80% | 82.50% | 82.50% | |
Expected volatility, Minimum | 82.00% | |||
Expected volatility, Maximum | 82.80% | |||
Risk-free interest rate | 2.80% | 2.10% | 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 | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Income Tax Disclosure [Abstract] | ||||
Income tax provision | $ 0 | $ 0 | $ 0 | $ 0 |
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 | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Numerator: | ||||
Net loss | $ (6,775) | $ (1,880) | $ (11,722) | $ (4,137) |
Denominator: | ||||
Weighted-average shares of common stock outstanding | 2,044,027 | 569,364 | 1,404,392 | 539,419 |
Net loss per common share, basic and diluted | $ (3.31) | $ (3.30) | $ (8.35) | $ (7.67) |
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 | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 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 | 2,368,346 | 12,426,267 | 2,368,346 | 12,426,267 |
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 | 11,334,414 | 11,334,414 | ||
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 | 190,680 | 357,190 | 190,680 | 357,190 |
Related Party Disclosure - Addi
Related Party Disclosure - Additional Information (Details) - Michael Kauffman - USD ($) | Apr. 01, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 |
Clinical and Scientific Advisory Services | |||||
Related Party Transaction [Line Items] | |||||
Related party transaction expense | $ 3,000 | ||||
Consulting | |||||
Related Party Transaction [Line Items] | |||||
Related party transaction expense | $ 8,100 | $ 9,000 | $ 17,100 | $ 9,000 |