Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2018 | Nov. 03, 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 | EIDX | |
Entity Registrant Name | Eidos Therapeutics, Inc. | |
Entity Central Index Key | 1,731,831 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Non-accelerated Filer | |
Entity Small Business | true | |
Entity Emerging Growth Company | true | |
Entity Ex Transition Period | true | |
Entity Common Stock, Shares Outstanding | 36,747,182 |
Condensed Balance Sheets (Unaud
Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Current assets: | ||
Cash and cash equivalents | $ 166,568 | $ 5,497 |
Related party receivable | 29 | 67 |
Prepaid expenses and other current assets | 3,248 | 484 |
Total current assets | 169,845 | 6,048 |
Property and equipment, net | 218 | 114 |
Other assets | 163 | 181 |
Total assets | 170,226 | 6,343 |
Current liabilities: | ||
Accounts payable | 2,417 | 566 |
Related party payable | 206 | 372 |
Accrued expenses and other current liabilities | 3,427 | 1,300 |
Total current liabilities | 6,050 | 2,238 |
Other liabilities | 357 | 273 |
Total liabilities | 6,407 | 2,511 |
Commitments and contingencies (Note 12) | ||
Redeemable convertible preferred stock, $0.001 par value; 0 and 14,000,000 shares authorized as of September 30, 2018 and December 31, 2017, respectively; 0 and 12,856,325 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively; aggregate liquidation preference of $17,032 as of December 31, 2017; | 17,028 | |
Stockholders’ equity (deficit): | ||
Preferred stock, $0.001 par value, 5,000,000 and 0 shares authorized as of September 30, 2018 and December 31, 2017, respectively; and no shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively; | ||
Common stock, $0.001 par value; 150,000,000 and 20,000,000 shares authorized as of September 30, 2018 and December 31, 2017, respectively; 36,711,661 and 5,137,771 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively; | 37 | 4 |
Additional paid-in capital | 214,690 | 1,332 |
Accumulated deficit | (50,908) | (14,532) |
Total stockholders’ equity (deficit) | 163,819 | (13,196) |
Total liabilities, redeemable convertible preferred stock and stockholders’ equity (deficit) | $ 170,226 | $ 6,343 |
Condensed Balance Sheets (Una_2
Condensed Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands | 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 | 14,000,000 |
Redeemable convertible preferred stock, shares issued | 0 | 12,856,325 |
Redeemable convertible preferred stock, shares outstanding | 0 | 12,856,325 |
Redeemable convertible preferred stock, aggregate liquidation preference | $ 17,032 | |
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 5,000,000 | 0 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 150,000,000 | 20,000,000 |
Common stock, shares issued | 36,711,661 | 5,137,771 |
Common stock, shares outstanding | 36,711,661 | 5,137,771 |
Condensed Statements of Operati
Condensed 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 (includes related party expense (benefit) of ($23) and $30, and $3 and $57, respectively) | $ 7,931 | $ 2,283 | $ 21,362 | $ 5,583 |
General and administrative (includes related party expense of $165 and $183, and $924 and $394, respectively) | 2,619 | 490 | 6,656 | 1,322 |
Total operating expenses | 10,550 | 2,773 | 28,018 | 6,905 |
Loss from operations | (10,550) | (2,773) | (28,018) | (6,905) |
Other income (expense), net | 374 | (1,681) | 75 | |
Loss on extinguishment of debt | 0 | (6,677) | ||
Net loss | $ (10,176) | $ (2,773) | $ (36,376) | $ (6,830) |
Net loss per share | $ (0.29) | $ (0.74) | $ (2.28) | $ (1.95) |
Weighted-average shares used in computing net loss per share basic, and diluted | 35,591,518 | 3,752,883 | 15,976,228 | 3,504,790 |
Condensed Statements of Opera_2
Condensed Statements of Operations (Unaudited) (Parenthetical) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Income Statement [Abstract] | ||||
Research and development expense (benefit) included from related party | $ (23) | $ 30 | $ 3 | $ 57 |
General and administrative expense included from related party | $ 165 | $ 183 | $ 924 | $ 394 |
Condensed Statements of Cash Fl
Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands | 9 Months Ended | |
Sep. 30, 2018 | Sep. 30, 2017 | |
Cash Flows From Operating Activities: | ||
Net loss | $ (36,376) | $ (6,830) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Depreciation and amortization | 40 | 2 |
Stock-based compensation expense | 2,643 | 101 |
Accrued interest on convertible promissory notes | 48 | |
Change in fair value of redeemable convertible preferred stock tranche liability | (1,334) | (75) |
Change in fair value of redeemable convertible preferred stock warrant liability | 2,628 | |
Amortization of debt discount | 713 | |
Loss on extinguishment of debt | 6,677 | |
Changes in assets and liabilities: | ||
Related party receivable | 38 | (20) |
Prepaid expenses and other current assets | (2,764) | (748) |
Other assets | 18 | 6 |
Accounts payable | 1,852 | 888 |
Accrued expenses and other liabilities | 2,278 | 550 |
Related party payable | (166) | (32) |
Net cash used in operating activities | (23,705) | (6,158) |
Cash Flows From Investing Activities: | ||
Purchase of property and equipment | (144) | (6) |
Net cash used in investing activities | (144) | (6) |
Cash Flows From Financing Activities: | ||
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs | 63,875 | 12,993 |
Proceeds from issuance of convertible promissory notes | 10,000 | |
Proceeds from issuance of common stock upon exercise of stock options and restricted stock | 75 | 15 |
Proceeds from issuance of initial public offering, net of issuance costs | 110,970 | |
Net cash provided by financing activities | 184,920 | 13,008 |
Net increase in cash and cash equivalents | 161,071 | 6,844 |
Cash and Cash Equivalents, Beginning of Period | 5,497 | 1,956 |
Cash and Cash Equivalents, End of Period | 166,568 | 8,800 |
Supplemental disclosure of non-cash financing activities: | ||
Settlement of fair value of redeemable convertible preferred stock put option asset | 1,527 | |
Settlement of fair value of redeemable convertible preferred stock tranche liability | 694 | 240 |
Vesting of restricted stock and early exercised options | 135 | $ 9 |
Conversion of convertible note payable and accrued interest into redeemable convertible preferred stock | 10,048 | |
Conversion of redeemable convertible preferred stock to common stock at closing of initial public offering | 97,276 | |
Reclassification of redeemable convertible preferred stock warrant liability to equity | $ 3,506 |
Organization and Description of
Organization and Description of Business | 9 Months Ended |
Sep. 30, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Organization and Description of Business | Note 1. Organization and Description of Business Eidos Therapeutics, Inc., or the Company, was incorporated as an S corporation in the state of Delaware on August 6, 2013. The Company was converted into a C corporation on April 4, 2016 in conjunction with its Series Seed redeemable convertible preferred stock financing. The Company is advancing a drug candidate to treat multiple forms of transthyretin amyloidosis, which leads to organ damage, loss of organ function and eventual death from abnormal buildup of protein deposits predominantly in the heart and peripheral nervous system. The Company has been primarily engaged in business planning, research, recruiting personnel and raising capital. The Company is headquartered in San Francisco, California and it operates as one operating segment. Stock Split In June 2018, the Company’s board of directors approved an amendment to the Company’s amended and restated certificate of incorporation to effect a stock split of the Company’s issued and outstanding common stock at a 1.196-for-1 ratio, which was effected on June 7, 2018. In connection with the stock split, the authorized shares of common stock were increased from 27,000,000 to 32,292,000. The par value of common stock and redeemable convertible preferred stock was not adjusted as a result of the stock split. All issued and outstanding common stock, options to purchase common stock and per share amounts contained in the condensed financial statements have been retroactively adjusted to reflect the stock split for all periods presented. Initial Public Offering On June 19, 2018, the Company’s registration statement on Form S-1 (File No. 333-225235) relating to its initial public offering (“IPO”) of common stock became effective. The IPO closed on June 22, 2018 at which time the Company issued 7,187,500 shares of its common stock at a price of $17.00 per share, which included shares issued upon the underwriters’ exercise of their overallotment option to purchase 937,500 additional shares. In addition, upon closing the IPO, all outstanding shares of the redeemable convertible preferred stock and warrants converted into 29,564,527 shares of common stock and there are no shares of redeemable convertible preferred stock outstanding. The Company received an aggregate of $111.0 million in cash, net of underwriting discounts and commissions, and after deducting offering costs paid by the Company. Liquidity In accordance with Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. Since inception, the Company has funded its operations with proceeds from sales of redeemable convertible preferred stock, common stock, convertible promissory notes. The Company has incurred recurring losses since inception, including net losses of $10.2 million and $36.4 million for the three and nine months ended September 30, 2018, respectively. As of September 30, 2018, the Company had an accumulated deficit of $50.9 million. The Company expects to continue to generate operating losses for the foreseeable future. As of the issuance date of the unaudited condensed financial statements, the Company expects that funds received from the completion of its IPO in June 2018, together with its cash and cash equivalents, totaling $166.6 million as of September 30, 2018, will be sufficient to fund its anticipated operating and capital expenditure requirements through at least 12 months from the issuance date of these unaudited condensed 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 | Note 2. Summary of Significant Accounting Policies Basis of preparation These unaudited condensed financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP. These financial statements include transactions with , a controlling stockholder in the Company. For the periods presented, BBP LLC has provided consulting and management services to the Company in the ordinary course of business, including certain executive personnel, facility related costs, advisory services, insurance costs and other general corporate expenses. These allocations were made based on direct usage, when identifiable, with the remainder allocated primarily based on a proportional share of headcount. The Company’s historical financial statements do not purport to reflect what the Company’s results of operations, financial position, or cash flows would have been if the Company had operated as an independent entity during the periods presented. Management believes the basis on which the expenses have been allocated to be a reasonable reflection of the utilization of services provided to or the benefit received by the Company during the periods presented. For more information on the allocated costs and related party transactions , see Note 6. Unaudited Interim Condensed Financial Statements The accompanying unaudited condensed financial statements have been prepared in accordance with GAAP and applicable rules and regulations of the Securities and Exchange Commission, or the SEC, regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2017 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Company’s financial information. 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 interim period or for any other future year. The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2017, which are included in the Company’s prospectus related to the Company’s IPO, filed with the SEC on June 21, 2018, pursuant to Rule 424(b) under the Securities Act of 1933. Use of estimates The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to the fair value of the redeemable convertible preferred stock tranche liability, the preferred stock put option asset, the fair value of the redeemable convertible preferred stock warrant liability, the fair value of the Company’s common stock, stock-based compensation, the useful lives of fixed assets, accruals for research and development activities and income taxes. Management bases its estimates on historical experience and on other relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Concentrations of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents. All the Company’s cash is held by one financial institution that management believes is of high credit quality. Such deposits may, at times, exceed federally insured limits. Cash and Cash Equivalents Cash equivalents that are readily convertible to cash are stated at cost, which approximates fair value. The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. There were no cash equivalents at December 31, 2017. As of September 30, 2018, the Company had cash and cash equivalents of $166.6 million. The Company’s cash equivalents are invested in highly-rated money market funds. Fair Value of Financial Instruments Fair value accounting is applied for all financial assets and liabilities that are recognized or disclosed at fair value in the condensed unaudited financial statements on a recurring basis (at least annually). The carrying amount of the Company’s financial instruments, including cash equivalents, accounts payable and accrued expenses and other payables approximate fair value due to their short-term maturities. See Note 3. Fair value measurements regarding the fair value of the Company’s redeemable convertible preferred stock put option asset, redeemable convertible preferred stock tranche liability and redeemable convertible preferred stock warrant liability. Research and Development Costs and Accrued Research and Development Research and development costs are expensed as incurred and consist of salaries and benefits, stock-based compensation expense, lab supplies and facility costs, as well as fees paid to others that conduct certain research and development activities on the Company’s behalf. The Company accrues for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of preclinical studies and clinical trials, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and include these costs in accrued expenses and other payables in the condensed unaudited balance sheets and within research and development expense in the condensed unaudited statements of operations. These costs are a significant component of the Company’s research and development expenses. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers. The Company makes significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled, and the rate of patient enrollments may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. Accrued repurchase liability for common stock The Company records as a liability, within accrued expenses and other current liabilities, the purchase price of unvested common stock that the Company has a right to repurchase if and when the stockholder ceases to be a service provider to the Company before the end of the requisite service period. The proceeds are recorded as a liability and the proceeds related to the vested common stock is reclassified to additional paid-in capital as the Company’s repurchase right lapses. Redeemable convertible preferred stock put option asset The Company has determined that its right to cause the Series B shareholders to purchase additional shares of redeemable convertible preferred stock upon the achievement of the specified milestone represented a freestanding financial instrument. The instrument was classified as an asset on the balance sheets based on its relative fair value. The put option asset balance was reclassified to redeemable convertible preferred stock upon the settlement of the additional shares in May 2018. Redeemable convertible preferred stock tranche liability The Company has determined that its obligation to issue additional shares of redeemable convertible preferred stock upon the achievement of certain milestones or at the option of the holder represents a freestanding financial instrument. The instrument was classified as a liability on the balance sheets and was subject to remeasurement at each balance sheet date and any change in fair value is recognized through other income (expense), net in the condensed statements of operations. The tranche liability balance was reclassified to redeemable convertible preferred stock upon the settlement of the additional shares in May 2018. Redeemable convertible preferred stock warrant liability The Company’s redeemable convertible preferred stock warrants require liability classification and accounting as the underlying preferred stock is deemed redeemable. Upon initial recognition, the warrants are recorded at their estimated fair value. The warrants are subject to remeasurement at each balance sheet date, with changes in fair value recognized as a component of other income (expense), net. The Company continued to adjust the liability for changes in fair value until the completion of the Company’s IPO, at which time all redeemable convertible preferred stock warrants were net exercised into shares of common stock and the related redeemable convertible preferred stock warrant liability was reclassified to common stock and additional paid-in capital. Net loss per share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per common share is the same as basic net loss per share since the effects of potentially dilutive securities are antidilutive given the Company’s loss position. Stock-Based Compensation The Company periodically grants stock options and awards to employees and non-employees in non-capital raising transactions as compensation for services rendered. The Company accounts for stock option grants to employees whereby the fair value of the award is measured on the date of grant and recognized over the vesting period. The Company accounts for stock option grants to non-employees whereby the amount of stock compensation expense recognized is determined based upon the measurement date at either a) the date at which a performance commitment is reached, or b) at the date at which the necessary performance to earn the equity instruments is complete. Non-employee stock-based compensation expenses generally are amortized over the vesting period on a straight-line basis. In certain circumstances where there are no future performance requirements by the non-employee, option grants are immediately vested and the total stock-based compensation charge is recorded in the period of the measurement date. The fair value of the Company's common stock option grants is estimated using a Black-Scholes option pricing model, which uses certain assumptions related to risk-free interest rates, expected volatility, expected life of the common stock options, and future dividends. Compensation expense is recorded based upon the value derived from the Black-Scholes option pricing model and based on actual experience. The assumptions used in the Black-Scholes option pricing model could materially affect compensation expense recorded in future periods. The Company has in the past issued restricted shares of its common stock for share-based compensation programs. The Company measures the compensation cost with respect to restricted shares issued to employees based upon the estimated fair value of the equity instruments at the date of the grant and is recognized as expense over the period which an employee is required to provide services in exchange for the award. Recent accounting pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-02, Leases (Topic 842 In June 2018, the FASB issued ASU No. 2018-07, Stock-based Compensation: Improvements to Nonemployee Share-based Payment Accounting date of Topic 606. Entities will apply the ASU by recognizing a cumulative-effect adjustment to retained earnings as of the beginning of the annual period of adoption. The Company is currently evaluating the impact that ASU 2018-07 will have on its condensed financial statements. In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which amends ASC 820, Fair Value Measurement. This ASU modifies the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The effective date is the first quarter of fiscal year 2020, with early adoption permitted for the removed disclosures and delayed adoption until fiscal year 2020 permitted for the new disclosures. The removed and modified disclosures will be adopted on a retrospective basis and the new disclosures will be adopted on a prospective basis. The Company has determined the adoption will not have a material effect on the its condensed financial statements. In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. The final rule became effective on November 5, 2018. The Company is evaluating the impact of this guidance on its condensed financial statements. |
Fair Value Measurement
Fair Value Measurement | 9 Months Ended |
Sep. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurement | Note Financial assets and liabilities are recorded at fair value. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value 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. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. There were no financial assets outside of cash in an operating account as of December 31, 2017 and September 30, 2018. There were no transfers between Level 1, Level 2 and Level 3 categories during the periods presented. There were no financial liabilities measured at fair value as of December 31, 2017 and September 30, 2018. There were no transfers between Level 1, Level 2 and Level 3 categories during the periods presented. Following is the activity related to Level 3 financial assets and liabilities of the Company during the nine months ended September 30, 2018: Redeemable convertible preferred stock put option asset The fair value of the redeemable convertible preferred stock put option asset was based on significant inputs not observed in the market and thus represents a Level 3 measurement. The Company estimates the fair value of the redeemable convertible preferred stock put option asset using the Black-Scholes option pricing model. Redeemable convertible preferred stock put option: Balance at December 31, 2017 $ — Issuance of Series B redeemable convertible preferred stock tranche put option 1,527 Settlement of redeemable convertible preferred stock tranche liability due to the issuance of Series B redeemable convertible preferred stock (1,527 ) Balance at September 30, 2018 $ — Redeemable convertible preferred stock tranche liability The fair value of the redeemable convertible preferred stock tranche liability was based on significant inputs not observed in the market and thus represents a Level 3 measurement. The Company estimates the fair value of the redeemable convertible preferred stock tranche liability using the Black-Scholes option pricing model. The following table sets forth a summary of the changes in the fair value of the Company’s redeemable convertible preferred stock tranche liability (in thousands): Redeemable convertible preferred stock tranche liability: Balance at December 31, 2017 $ — Issuance of Series B redeemable convertible preferred stock tranche liability 2,028 Change in fair value upon revaluation (1,334 ) Settlement of redeemable convertible preferred stock tranche liability due to the issuance of Series B redeemable convertible preferred stock (694 ) Balance at September 30, 2018 $ — Redeemable convertible preferred stock warrant liability The fair value of the redeemable convertible preferred stock warrant liability is based on significant inputs not observed in the market and thus represents a Level 3 measurement. The Company estimates the fair value of the redeemable convertible preferred stock warrant liability using the Black-Scholes option pricing model. The following table sets forth a summary of the changes in the fair value of the Company’s redeemable convertible preferred stock warrant liability (in thousands): Redeemable convertible preferred stock warrant liability: Balance at December 31, 2017 $ — Issuance of redeemable convertible preferred stock warrant liability 878 Change in fair value upon revaluation 2,628 Reclassification of redeemable convertible preferred stock warrant liability to common stock (3,506 ) Balance at September 30, 2018 $ — Embedded derivative in convertible note The convertible note issued in February 2018 had a redemption feature that was determined to be an embedded derivative requiring bifurcation and separate accounting. The fair value of the derivative was determined based on an income approach that identified the cash flows using a “with-and-without” valuation methodology. The inputs used to determine the estimated fair value of the derivative instrument were based largely on the probability of an underlying event triggering the embedded derivative occurring and the timing of such event. The following table sets forth a summary of the changes in the fair value of the Company’s embedded derivative in convertible note (in thousands): Derivative instrument: Balance at December 31, 2017 $ — Initial fair value of the embedded derivative issued with the convertible note 4,153 Change in fair value upon revaluation — Extinguishment of the embedded derivative (4,153 ) Balance at September 30, 2018 $ — |
Condensed Balance Sheet Compone
Condensed Balance Sheet Components | 9 Months Ended |
Sep. 30, 2018 | |
Balance Sheet Related Disclosures [Abstract] | |
Condensed Balance Sheet Components | Note 4. Condensed balance sheet components Property and equipment, net Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2018 2017 Leasehold improvements $ 86 $ 77 Computer equipment 82 29 Office furniture and equipment 94 12 Total Property and equipment, cost 262 118 Less: Accumulated depreciation and amortization (44 ) (4 ) Property and equipment, net $ 218 $ 114 The Company recorded $16,000 and $40,000 for the depreciation and amortization during the three and nine months ended September 30, 2018, respectively; and $1,000 and $2,000 for the depreciation and amortization during the three and nine months ended September 30, 2017, respectively. Accrued expenses and other current liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2018 2017 Accrued research and development costs $ 2,203 $ 564 Accrued employee related expenses 725 606 Liability for unvested stock, short-term 135 109 Accrued other current liabilities 364 21 $ 3,427 $ 1,300 As of December 31, 2017, and September 30, 2018, the balances of $208,000 and $286,000, respectively, in other liabilities related to the long-term liability for unvested stock. |
Convertible Promissory Notes
Convertible Promissory Notes | 9 Months Ended |
Sep. 30, 2018 | |
Debt Disclosure [Abstract] | |
Convertible Promissory Notes | Note 5. Convertible promissory notes In February 2018, the Company entered into a Note and Warrant Purchase Agreement with BBP LLC and Stanford University. The Company issued two convertible promissory notes in an aggregate principal amount of $10.0 million. The notes had a maturity date of the earliest of a qualified financing, a deemed liquidation event, a qualified initial public offering or February 2019. The convertible promissory notes had an annual interest rate of 5.0%. The convertible promissory notes were convertible into future preferred stock at a 30% discount to the price paid by investors in the Company’s next preferred equity financing of at least $10.0 million or convertible into common stock at the price per share in an IPO with aggregate proceeds of at least $30.0 million. In connection with the convertible promissory notes, the Company issued warrants for the purchase of $4.0 million in shares of the Company’s Series Seed redeemable convertible preferred stock or the Company’s preferred stock in the next equity financing. The exercise period commences upon the earlier of the closing of the next qualified financing and the consummation of a deemed liquidation event. The exercise price of the warrant was the price per share in the next equity financing if the warrant was exercisable for the Company’s redeemable convertible preferred stock in the next qualified financing, or $1.3248 per share if the warrant was exercisable for shares of Series Seed redeemable convertible preferred stock. If the warrant remained outstanding upon the consummation of the IPO, the warrant would automatically be deemed net-exercised in full immediately prior to the completion of the IPO at the initial public offering price. Upon issuance of the convertible promissory notes, the Company recorded the fair value of the warrants of $877,000 as a debt discount and redeemable convertible preferred stock warrant liability. The convertible promissory notes also contained a redemption feature that was determined to be an embedded derivative requiring bifurcation and separate accounting. The fair value of the embedded derivative liability at issuance was determined to be $4.2 million and was recorded as an additional debt discount. The debt discount was accreted using the effective interest method as additional interest expense over the term of the convertible note. Changes in the fair value of the embedded derivative and redeemable convertible preferred stock warrant liability have also been recorded within other income (expense), net, in the condensed statement of operations for the nine months ended September 30, 2018. During the three and nine months ended September 30, 2018, the Company recognized interest expense of $0 and $761,000 related to the accrued interest and amortization of debt discount, respectively. No expenses were recorded in 2017 related to this note. As the convertible notes payable contained an embedded conversion feature that does not qualify for derivative treatment, the Company evaluated if there was a beneficial conversion feature (BCF). The Company determined there was a BCF of $2.4 million as the effective conversion rate of the convertible note was below market value. The Company accounted for the value of the BCF as a debt discount, which was being accreted to interest expense over the life of the related debt using the effective interest method. The value of the BCF was recorded to additional paid-in capital with the offset to discount on convertible notes payable. The debt discount was to be accreted to other income (expense), net over the one-year original term of the convertible notes payable. During the three and nine months ended September 30, 2018, the Company recorded $0 and $228,000 related to this debt discount, respectively. No expense was recorded in 2017 related to this BCF. On March 29, 2018, the convertible notes payable were converted into Series B redeemable convertible preferred stock, and the remaining amount of unamortized debt discount was recorded as an extinguishment of debt. In March 2018, as a result of the Series B redeemable convertible preferred stock financing event, the outstanding principal and accrued interest of $10.0 million related to the convertible promissory notes automatically converted into 1,324,823 shares of Series B redeemable convertible preferred stock using a conversion price of $7.5844. In connection with the conversion of the convertible promissory note, for the three and nine months ended September 30, 2018, the Company recorded $0 and $6.7 million, related to the loss on the extinguishment of the convertible promissory notes, respectively. In the addition, the warrants associated with the convertible note became warrants to purchase 369,180 shares of the Company’s Series B redeemable convertible preferred stock at an exercise price of $10.8348 per share. |
Related Party Transactions
Related Party Transactions | 9 Months Ended |
Sep. 30, 2018 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | Note 6. Related party transactions BridgeBio Pharma LLC BridgeBio Pharma LLC and its affiliates, or BBP LLC, is a controlling stockholder in the Company, as it owned 75% and 53% of the Company’s total outstanding shares as of December 31, 2017 and September 30, 2018. In April 2016, the Company began receiving consulting, management, facility and infrastructure services pursuant to a services agreement with BBP LLC. The initial agreement was entered into on March 1, 2016 and was superseded by the subsequent agreement effective as of May 1, 2017. The Company incurred the following expenses under the agreement with BBP LLC (in thousands): Three-Month Nine-Month Periods Ended September 30, September 30, 2018 2017 2018 2017 Rent $ 14 $ 25 $ 33 $ 50 Facility 20 21 125 34 Consulting 108 167 769 367 $ 142 $ 213 $ 927 $ 451 As of December 31, 2017, and September 30, 2018, the Company had an outstanding receivable from BBP LLC of $67,000 and $29,000, related to providing services to other subsidiaries of BBP LLC. As of December 31, 2017 and September 30, 2018, the Company had an outstanding liability due to BBP LLC of $372,000 and $206,000, respectively. Founders Dr. Graef Consulting Agreement In April 2016, the Company entered into a consulting agreement with Dr. Graef, one of the Company’s founders. Pursuant to the consulting agreement, Dr. Graef agreed to provide consulting services in connection with the discovery and development of novel TTR stablizers. As compensation for these services, Dr. Graef is entitled to an annual fee in the amount of up to $150,000 and reimbursement by the Company for pre-approved expenses. The consulting agreement has a term of four years but may be terminated by either party for any reason with thirty days’ prior notice. In December 2017, we issued to Dr. Graef 195,273 shares of our common stock in order to offset dilution to her ownership in connection with our issuance of additional shares of Series Seed Preferred Stock in financing transactions. In addition, we agreed to make a “gross-up” payment of $83,073 to Dr. Graef for the taxes owed by Dr. Graef as a result of such issuance of common stock, which payment was made in January 2018. As of June 20, 2018 Dr. Graef is not considered a related party. Dr. Alhamadsheh Consulting Agreement In August 2016, the Company entered into a consulting agreement with Dr. Alhamadsheh, one of the Company’s founders. Pursuant to the consulting agreement, Dr. Alhamadsheh agreed to provide consulting services in connection with the discovery and development of novel TTR stablizers. As compensation for these services, Dr. Alhamadsheh is entitled to an annual fee in the amount of up to $115,000 and reimbursement by the Company for pre-approved expenses. The consulting agreement has a term of four years but may be terminated by either party for any reason with thirty days’ prior notice. In December 2017, we issued to Dr. Alhamadsheh 195,273 shares of our common stock in order to offset dilution to his ownership in connection with our issuance of additional shares of Series Seed Preferred Stock in financing transactions. In addition, we agreed to make a “gross-up” payment of $83,073 to Dr. Alhamadsheh for the taxes owed by Dr. Alhamadsheh as a result of such issuance of common stock, which payment was made in January 2018. As of June 20, 2018 Dr. Alhamadsheh is not considered a related party. The Company incurred the following expenses (benefit) for services under the consulting agreements and stock-based compensation (in thousands): Three-Month Periods Ended Nine-Month Periods Ended September 30, September 30, 2018 2017 2018 2017 Dr. Graef $ (180 ) $ 40 $ 602 $ 124 Dr. Alhamadsheh (189 ) 31 575 98 $ (369 ) $ 71 $ 1,177 $ 222 Option Award to Dr. Huh In May 2018, our board of directors approved a grant to Dr. Huh (a member of our board of directors) of an option to purchase 83,720 shares of our common stock pursuant to the Company’s 2018 Stock Option and Incentive Plan (the “2018 Plan”). The option will vest in equal annual installments over three years from the grant date, subject to Dr. Huh’s continued service as a director through the applicable vesting dates. The award is subject to full accelerated vesting upon a “sale event,” as defined in the 2018 Plan. For the three and nine months ended September 30, 2018 the Company recorded $75,000 and $85,000 related to these awards. |
Redeemable Convertible Preferre
Redeemable Convertible Preferred Stock | 9 Months Ended |
Sep. 30, 2018 | |
Temporary Equity Disclosure [Abstract] | |
Redeemable Convertible Preferred Stock | Note 7. Redeemable convertible preferred stock In March 2018, the Company sold an aggregate of 1,476,715 shares of Series B redeemable convertible preferred stock financing in an initial closing for total gross proceeds of $16.0 million. An additional 4,430,162 shares of Series B redeemable convertible preferred stock may be issued in an additional closing contingent upon the release of specified data study either upon the request of the Company for investors to purchase the shares (purchased put option) or the investors may call for the purchase of such shares (tranche liability or call option). The Company has determined that its right to cause the Series B shareholders to purchase additional shares of redeemable convertible preferred stock upon the achievement of the specified milestone represented a freestanding financial instrument. The Company recorded the redeemable convertible preferred stock put option asset, based on its relative fair value of $1.5 million as an asset. In addition, the Company determined it was obligated to sell additional shares of Series B redeemable convertible preferred stock contingent upon the achievement of the specified milestone. This additional closing was also deemed to be freestanding financial instrument. Upon issuance of the Series B redeemable convertible preferred stock, the Company recorded the redeemable convertible preferred stock tranche liability incurred in connection with its Series B redeemable convertible preferred stock as a derivative financial instrument liability at the fair value of $2.0 million on the date of issuance and remeasured the liability on each subsequent balance sheet dates through the issuance of the additional shares In May 2018, the Company issued 4,430,162 shares of Series B redeemable convertible preferred stock at a purchase price of $10.8348 per share, for total proceeds of $48.0 million. The issuance of the shares is in connection with the additional shares related to the put option asset pertaining to the Series B redeemable convertible preferred stock financing in March 2018. The tranche liability and put option asset balances were reclassified to redeemable convertible preferred stock upon the closing of the sale of additional shares. Following the closing of the IPO, all outstanding shares of the redeemable convertible preferred stock converted into 24,025,270 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of redeemable convertible preferred stock outstanding as of September 30, 2018. |
Redeemable Convertible Prefer_2
Redeemable Convertible Preferred Stock Tranche Liability and Put Option Asset | 9 Months Ended |
Sep. 30, 2018 | |
Temporary Equity Disclosure [Abstract] | |
Redeemable Convertible Preferred Stock Tranche Liability and Put Option Asset | Note 8. Redeemable convertible preferred stock tranche liability and put option asset In March 2018, the Company entered into a Series B Preferred Stock Purchase Agreement, or the Agreement, for the issuance of up to 7,231,700 shares of Series B redeemable convertible preferred stock at a price of $10.8348 per share in two closings. Upon the initial closing on March 29, 2018, 1,476,715 shares of Series B redeemable convertible preferred stock were issued for gross proceeds of $16.0 million and 1,324,823 shares were issued upon conversion of the outstanding convertible promissory note principal balance and accrued interest of $10.0 million. The Agreement, provided that the Company could issue an additional 4,430,162 shares under the same terms as the initial closing, in an additional closing contingent upon the achievement of certain milestone. Either the investors or the Company could provide written notice for the additional closing to occur. The Company determined that its obligation to issue additional shares of its redeemable convertible preferred stock and the Company’s right to request investors to purchase additional shares of its redeemable convertible preferred stock represent freestanding financial instruments. The freestanding redeemable convertible preferred stock tranche liability was initially recorded at fair value, with fair value changes recorded within other income (expense), net in the condensed statement of operations. The purchased put option was recorded at fair value without subsequent remeasurement. The Company continued to adjust the tranche liability for changes in the fair value until the settlement of the redeemable convertible preferred stock additional closing in May 2018. At such time, the remaining value of the redeemable convertible preferred stock tranche liability and the put option asset were reclassified to redeemable convertible preferred stock with no further remeasurement required. The Company has recorded a redeemable convertible preferred stock tranche liability and a put option asset in March 2018 of $2.0 million and $1.5 million, respectively, related to the Series B redeemable convertible preferred stock financing. The Company estimated the fair value of the preferred stock liability and the put option asset using a Black-Scholes option pricing model using the following assumptions: Expected term —The expected term represents the period for which the redeemable convertible preferred stock tranche liability and put option asset are expected to be outstanding, which is estimated to be the remaining contractual term. Expected volatility —The volatility data was estimated based on a study of publicly traded industry peer companies, as there is no trading history for our redeemable convertible preferred stock. For purposes of identifying these comparable peer companies, the Company considered the industry, stage of development, size and financial leverage. The Company has measured historical volatility over a period equivalent to the expected term and believes that historical volatility provides a reasonable estimate of future expected volatility. Expected dividends —The Black-Scholes valuation model calls for a single expected dividend yield as an input. The Company currently has no history or expectation of paying cash dividends on its redeemable convertible preferred stock. Risk-free interest rate —The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues similar in duration to the expected term of the redeemable convertible preferred stock tranche liability and put option asset. The Company used the following assumptions: a term of 0.08 years, a risk-free rate of 1.63%, a volatility of 36.4%, and a dividend yield of 0.0%. In May 2018, the Company completed the closing of the Series B Second Tranche and issued 4,430,162 shares of Series B redeemable convertible preferred stock for net cash proceeds of $48.0 million. At this time the Series B redeemable convertible preferred stock liability was remeasured at $0.7 million, determined using a (“PWERM”). The PWERM included probabilities of three IPO scenarios occurring in June 2018. The scenarios were weighted based on the Company’s estimate of each event occurring in deriving the estimated fair value. Upon the closing of the Series B Second Tranche, the Series B redeemable convertible preferred stock liability was terminated and the balance of the liability of $0.7 million was reclassified to redeemable convertible preferred stock. For the three and nine months ended September 30, 2018, the Company recorded a charge of $0 and $1.3 million, respectively, for the change in the fair value of the Series B redeemable convertible preferred stock liability in the condensed statements of operations . |
Stockholders' Equity and Stock-
Stockholders' Equity and Stock-Based Compensation | 9 Months Ended |
Sep. 30, 2018 | |
Stockholders Equity And Stock Based Compensation [Abstract] | |
Stockholders' Equity and Stock-Based Compensation | Note 9. Stockholders’ Equity and Stock-Based Compensation Stock Plans Equity Incentive Plan 2016 Equity Incentive Plan In April 2016, the Company established its 2016 Equity Incentive Plan, or the 2016 Plan, which provides for the granting of equity awards to employees and consultants of the Company. Awards granted under the 2016 Plan may be either incentive stock options, or ISOs, nonqualified stock options, or NSOs or restricted stock awards. ISOs may be granted only to Company employees (including officers and directors who are also employees). NSOs may be granted to Company employees and consultants. The exercise price of an ISO and NSO shall not be less than 100% of the estimated fair value of the shares on the date of grant, as determined by the board of directors. The exercise price of an ISO granted to an employee who at the time of grant is a 10% stockholder shall not be less than 110% of the estimated fair value of the shares on the date of grant, as determined by the board of directors. To date, options have a term of ten years and generally vest over a four-year period with annual cliff vesting and the balance monthly over 36 months. Upon completion of the Company’s IPO, the remaining shares available for issuance under the 2016 Plan were retired. 2018 Stock Option and Incentive Plan In May 2018, the Company’s board of directors and stockholders approved the 2018 Stock Option and Incentive Plan, or the 2018 Plan, to replace the 2016 Plan. The 2018 Plan became effective upon the IPO and is administered by the board of directors or a committee appointed by the board of directors, which determines the types of awards to be granted, including the number of shares subject to the awards, the exercise price and the vesting schedule. Under the 2018 Plan, 598,000 shares of the Company’s common stock have been initially reserved for the issuance of stock options, restricted stock units and other awards to employees, directors and consultants. Options granted under the 2018 Plan expire no later than 10 years from the date of grant. The exercise price of each option may not be less than 100% of the fair market value of the common stock at the date of grant. Options may be granted to stockholders possessing more than 10% of the total combined voting power of all classes of stocks of the Company at an exercise price at least 110% of the fair value of the common stock at the date of grant and the options are not exercisable after the expiration of 10 years from the date of grant. Employee stock options generally vest 25% upon one year of continued service to the Company, with the remainder in monthly increments over three additional years. Upon adoption of the 2018 Plan, no additional stock awards will be issued under the 2016 Plan. Options granted under the 2016 Plan that were outstanding on the date the 2018 plan became effective remain subject to the terms of the 2016 Plan. As of September 30, 2018, the Company has reserved 598,000 shares of common stock for issuance under the 2018 Plan. Employee Stock Purchase Plan In May 2018, the Company’s board of directors and stockholders approved the 2018 Employee Stock Purchase Plan, or the 2018 ESPP, which became effective upon the IPO. The 2018 ESPP is intended to qualify as an employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986, as amended, and is administered by the Company’s board of directors and the Compensation Committee of the board of directors. Under the 2018 ESPP, 143,520 shares of the Company’s common stock have been initially reserved for employee purchases of the Company’s common stock. The 2018 ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 20% of their eligible compensation. At the end of each offering period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock at the beginning of the offering period or at the end of each applicable purchase period. The first purchase period commenced upon the completion of the Company’s IPO, and ends on November 30, 2018. Stock Options The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2018: Weighted-Average Weighted-Average Aggregate Options Exercise Remaining Intrinsic Available for Options Price Per Contractual Value Grant Outstanding Share Term (years) (in thousands) Outstanding—December 31, 2017 670,996 846,164 $ 0.59 $ 4,383 Options granted (399,074 ) 399,074 $ 5.03 Options cancelled 321,916 (321,916 ) $ 0.59 Options retired (593,838 ) — $ - Additional authorized 598,000 — $ - Options granted (283,808 ) 283,808 $ 18.64 Options exercised — (149,350 ) $ 1.70 Exercised options repurchased 40,366 — $ 0.33 Options canceled 16,446 (16,446 ) $ 0.59 Outstanding—September 30, 2018 371,004 1,041,334 $ 7.05 9.46 $ 3,051 Options exercisable – September 30, 2018 153,813 $ 1.02 9.19 $ 1,378 Options vested and expected to vest – September 30, 2018 1,041,334 $ 7.05 9.46 $ 3,051 During the three months ended September 30, 2018, the estimated weighted-average grant-date fair value of common stock underlying options granted to employees was $13.18 per share. Accrued repurchase liability for common stock early exercises Stock awards granted pursuant to the 2016 Plan permitted option holders to elect to exercise unvested options in exchange for unvested common stock. Awards granted under the 2016 Plan that are exercised prior to vesting will continue to vest according to the respective award agreement, and such unvested shares are subject to repurchase by the Company at the optionee’s original exercise price or fair market value in the event the optionee’s service with the Company voluntarily or involuntarily terminates. As of December 31, 2017 and September 30, 2018, 1,219,389 and 988,238 shares, respectively, remained subject to a repurchase right by the Company, with a related liability included in accrued expenses and other liabilities in the condensed balance sheet of $317,000 and $421,000, respectively. Restricted stock In December 2017, the Company issued 390,546 shares of common stock for no consideration to the founders pursuant to the Series Seed Preferred Stock Purchase Agreement and license agreement in connection with certain anti-dilution rights held by these parties. If the shares issued under the license agreement represent less than 1% of the shares issued and outstanding common stock on an as-converted basis, the Company will issue additional common stock to the founders and Stanford University. The Company has the right to repurchase the common stock at the fair value per share on the date of repurchase, which right lapses as the shares vest, which is 25% cliff after one year and monthly thereafter over 36 months. In order to vest, the holders are required to provide continued service to the Company. As of December 31, 2017, and September 30, 2018, 390,546 and 292,910 shares remained subject to repurchase. The Company recognizes stock-based compensation expense over the period in which the related services from the founders are received. Stock-based compensation expense related to the restricted stock is recognized based on the vesting date fair value of stock using Black-Scholes pricing model and recorded as a research and development expense. During the three and nine months ended September 30, 2018 the Company recognized a benefit of $0.4 million and an expense of $1.0 million in connection with the stock-based compensation expense related to the restricted stock. During the three and nine months ended September 30, 2017 the Company did not recognize any stock-based compensation expense related to these awards. Stock-based compensation expense Total stock-based compensation expense related to all our stock-based awards was recorded on the statements of operations as follows (in thousands): Three-Month Periods Ended Nine-Month Periods Ended September 30, September 30, 2018 2017 2018 2017 Research and development $ (187 ) $ 26 $ 2,016 $ 100 General and administrative 443 1 627 2 Total stock-based compensation expense $ 256 $ 27 $ 2,643 $ 102 As of September 30, 2018, there was $11.6 million of total unrecognized compensation cost related to unvested stock-based compensation arrangements under the 2016 and 2018 Plans. The unrecognized stock-based compensation cost is expected to be recognized over a weighted-average period of 3.07 years. |
Net Loss per Share
Net Loss per Share | 9 Months Ended |
Sep. 30, 2018 | |
Earnings Per Share [Abstract] | |
Net Loss per Share | 10. Net Loss per share As the Company had net losses for the three and nine months ended September 30, 2018 and 2017, all potentially dilutive shares were determined to be anti-dilutive. The following table sets forth the computation of basic and diluted net loss per share (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 $ (10,176 ) $ (2,773 ) $ (36,376 ) $ (6,830 ) Denominator: Weighted-average shares used to compute net loss per common share, basic and diluted 35,591,518 3,752,883 15,976,228 3,504,790 Net loss per shares, basic and diluted $ (0.29 ) $ (0.74 ) $ (2.28 ) $ (1.95 ) The following shares of potentially dilutive securities have been excluded from the diluted net loss per share computations for the three and nine months ended September 30, 2018 and 2017 because their inclusion would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Redeemable convertible preferred stock on an as-converted basis — 15,376,164 — 15,376,164 Options to purchase common stock 1,041,334 100,719 1,041,334 100,719 Common stock subject to vesting or repurchase 988,238 424,475 988,238 424,475 2,029,572 15,901,358 2,029,572 15,901,358 |
License Agreement
License Agreement | 9 Months Ended |
Sep. 30, 2018 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
License Agreement | 11. License agreement In April 2016, the Company entered into a license agreement with the Board of Trustees of the Leland Stanford Junior University, or Stanford University relating to the Company’s drug discovery and development initiatives. Under this agreement, the Company has been granted certain worldwide exclusive licenses to use the licensed compounds. The Company paid an upfront license payment of $25,000 in April 2016, which was recorded as research and development expense and issued 56,809 |
Commitments and Contingencies
Commitments and Contingencies | 9 Months Ended |
Sep. 30, 2018 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 12. Commitments and contingencies Lease arrangements In September 2017, the Company entered into a one-year operating lease for laboratory facilities in San Francisco, California. In November 2017, the Company entered into an operating lease for an administrative facility in San Francisco, California, which expires in November 2022. The Company has provided a security deposit of $158,000 as collateral for the lease, which is included in other assets on the condensed balance sheet at September 30, 2018. Future minimum lease payments as of September 30, 2018 are as follows (in thousands): Operating Year Lease Commitments 2018 (remaining three months) $ 80 2019 327 2020 337 2021 347 2022 327 $ 1,418 The Company’s rent expense was $29,000 and $54,000 for the three and nine months ended September 30, 2017 and $107,000 and $311,000 for the three and nine months ended September 30, 2018, respectively. The amounts include the amounts incurred pursuant to the service agreement with BridgeBio Services, Inc., an affiliate of BridgeBio Pharma LLC (see Note 6). Rent expense is recognized on a straight-line basis over the terms of the Company’s leases and accordingly, the Company recorded the difference between rent expense and amount paid under the leases as deferred rent liability within other liabilities in the balance sheets. Incentives granted under the Company’s facility lease, including allowances to fund leasehold improvements, are deferred and recognized as adjustments to rent expense on a straight-line basis over the term of the lease. Indemnification In the ordinary course of business, the Company may provide indemnifications of varying scope and terms to vendors, lessors, business partners, board members, officers, and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements, services to be provided by the Company, negligence or willful misconduct of the Company, violations of law by the Company, or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with directors and certain officers and employees that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors, officers or employees. No demands have been made upon the Company to provide indemnification under such agreements, and thus, there are no claims that the Company is aware of that could have a material effect on the Company’s balance sheets, statements of operations, or statements of cash flows. |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
Sep. 30, 2018 | |
Accounting Policies [Abstract] | |
Basis of Preparation | Basis of preparation These unaudited condensed financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP. These financial statements include transactions with , a controlling stockholder in the Company. For the periods presented, BBP LLC has provided consulting and management services to the Company in the ordinary course of business, including certain executive personnel, facility related costs, advisory services, insurance costs and other general corporate expenses. These allocations were made based on direct usage, when identifiable, with the remainder allocated primarily based on a proportional share of headcount. The Company’s historical financial statements do not purport to reflect what the Company’s results of operations, financial position, or cash flows would have been if the Company had operated as an independent entity during the periods presented. Management believes the basis on which the expenses have been allocated to be a reasonable reflection of the utilization of services provided to or the benefit received by the Company during the periods presented. For more information on the allocated costs and related party transactions , see Note 6. |
Unaudited Interim Condensed Financial Statements | Unaudited Interim Condensed Financial Statements The accompanying unaudited condensed financial statements have been prepared in accordance with GAAP and applicable rules and regulations of the Securities and Exchange Commission, or the SEC, regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2017 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Company’s financial information. 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 interim period or for any other future year. The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2017, which are included in the Company’s prospectus related to the Company’s IPO, filed with the SEC on June 21, 2018, pursuant to Rule 424(b) under the Securities Act of 1933. |
Use of Estimates | Use of estimates The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to the fair value of the redeemable convertible preferred stock tranche liability, the preferred stock put option asset, the fair value of the redeemable convertible preferred stock warrant liability, the fair value of the Company’s common stock, stock-based compensation, the useful lives of fixed assets, accruals for research and development activities and income taxes. Management bases its estimates on historical experience and on other relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. |
Concentrations of Credit Risk | Concentrations of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents. All the Company’s cash is held by one financial institution that management believes is of high credit quality. Such deposits may, at times, exceed federally insured limits. |
Cash and Cash Equivalents | Cash and Cash Equivalents Cash equivalents that are readily convertible to cash are stated at cost, which approximates fair value. The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. There were no cash equivalents at December 31, 2017. As of September 30, 2018, the Company had cash and cash equivalents of $166.6 million. The Company’s cash equivalents are invested in highly-rated money market funds. |
Fair Value of Financial Instruments | Fair Value of Financial Instruments Fair value accounting is applied for all financial assets and liabilities that are recognized or disclosed at fair value in the condensed unaudited financial statements on a recurring basis (at least annually). The carrying amount of the Company’s financial instruments, including cash equivalents, accounts payable and accrued expenses and other payables approximate fair value due to their short-term maturities. See Note 3. Fair value measurements regarding the fair value of the Company’s redeemable convertible preferred stock put option asset, redeemable convertible preferred stock tranche liability and redeemable convertible preferred stock warrant liability. |
Research and Development Costs and Accrued Research and Development | Research and Development Costs and Accrued Research and Development Research and development costs are expensed as incurred and consist of salaries and benefits, stock-based compensation expense, lab supplies and facility costs, as well as fees paid to others that conduct certain research and development activities on the Company’s behalf. The Company accrues for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of preclinical studies and clinical trials, and contract manufacturing activities. The Company records the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and include these costs in accrued expenses and other payables in the condensed unaudited balance sheets and within research and development expense in the condensed unaudited statements of operations. These costs are a significant component of the Company’s research and development expenses. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers. The Company makes significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled, and the rate of patient enrollments may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. |
Accrued Repurchase Liability for Common Stock | Accrued repurchase liability for common stock The Company records as a liability, within accrued expenses and other current liabilities, the purchase price of unvested common stock that the Company has a right to repurchase if and when the stockholder ceases to be a service provider to the Company before the end of the requisite service period. The proceeds are recorded as a liability and the proceeds related to the vested common stock is reclassified to additional paid-in capital as the Company’s repurchase right lapses. |
Redeemable Convertible Preferred Stock Put Option Asset | Redeemable convertible preferred stock put option asset The Company has determined that its right to cause the Series B shareholders to purchase additional shares of redeemable convertible preferred stock upon the achievement of the specified milestone represented a freestanding financial instrument. The instrument was classified as an asset on the balance sheets based on its relative fair value. The put option asset balance was reclassified to redeemable convertible preferred stock upon the settlement of the additional shares in May 2018. |
Redeemable Convertible Preferred Stock Tranche Liability | Redeemable convertible preferred stock tranche liability The Company has determined that its obligation to issue additional shares of redeemable convertible preferred stock upon the achievement of certain milestones or at the option of the holder represents a freestanding financial instrument. The instrument was classified as a liability on the balance sheets and was subject to remeasurement at each balance sheet date and any change in fair value is recognized through other income (expense), net in the condensed statements of operations. The tranche liability balance was reclassified to redeemable convertible preferred stock upon the settlement of the additional shares in May 2018. |
Redeemable Convertible Preferred Stock Warrant Liability | Redeemable convertible preferred stock warrant liability The Company’s redeemable convertible preferred stock warrants require liability classification and accounting as the underlying preferred stock is deemed redeemable. Upon initial recognition, the warrants are recorded at their estimated fair value. The warrants are subject to remeasurement at each balance sheet date, with changes in fair value recognized as a component of other income (expense), net. The Company continued to adjust the liability for changes in fair value until the completion of the Company’s IPO, at which time all redeemable convertible preferred stock warrants were net exercised into shares of common stock and the related redeemable convertible preferred stock warrant liability was reclassified to common stock and additional paid-in capital. |
Net Loss Per Share | Net loss per share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted net loss per common share is the same as basic net loss per share since the effects of potentially dilutive securities are antidilutive given the Company’s loss position. |
Stock-Based Compensation | Stock-Based Compensation The Company periodically grants stock options and awards to employees and non-employees in non-capital raising transactions as compensation for services rendered. The Company accounts for stock option grants to employees whereby the fair value of the award is measured on the date of grant and recognized over the vesting period. The Company accounts for stock option grants to non-employees whereby the amount of stock compensation expense recognized is determined based upon the measurement date at either a) the date at which a performance commitment is reached, or b) at the date at which the necessary performance to earn the equity instruments is complete. Non-employee stock-based compensation expenses generally are amortized over the vesting period on a straight-line basis. In certain circumstances where there are no future performance requirements by the non-employee, option grants are immediately vested and the total stock-based compensation charge is recorded in the period of the measurement date. The fair value of the Company's common stock option grants is estimated using a Black-Scholes option pricing model, which uses certain assumptions related to risk-free interest rates, expected volatility, expected life of the common stock options, and future dividends. Compensation expense is recorded based upon the value derived from the Black-Scholes option pricing model and based on actual experience. The assumptions used in the Black-Scholes option pricing model could materially affect compensation expense recorded in future periods. The Company has in the past issued restricted shares of its common stock for share-based compensation programs. The Company measures the compensation cost with respect to restricted shares issued to employees based upon the estimated fair value of the equity instruments at the date of the grant and is recognized as expense over the period which an employee is required to provide services in exchange for the award. |
Recent Accounting Pronouncements | Recent accounting pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-02, Leases (Topic 842 In June 2018, the FASB issued ASU No. 2018-07, Stock-based Compensation: Improvements to Nonemployee Share-based Payment Accounting date of Topic 606. Entities will apply the ASU by recognizing a cumulative-effect adjustment to retained earnings as of the beginning of the annual period of adoption. The Company is currently evaluating the impact that ASU 2018-07 will have on its condensed financial statements. In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which amends ASC 820, Fair Value Measurement. This ASU modifies the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The effective date is the first quarter of fiscal year 2020, with early adoption permitted for the removed disclosures and delayed adoption until fiscal year 2020 permitted for the new disclosures. The removed and modified disclosures will be adopted on a retrospective basis and the new disclosures will be adopted on a prospective basis. The Company has determined the adoption will not have a material effect on the its condensed financial statements. In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. The final rule became effective on November 5, 2018. The Company is evaluating the impact of this guidance on its condensed financial statements. |
Fair Value Measurement (Tables)
Fair Value Measurement (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Fair Value Disclosures [Abstract] | |
Summary of Changes in Fair Value of Redeemable Convertible Preferred Stock Put Option Asset | The following table sets forth a summary of the changes in the fair value of the Company’s redeemable convertible preferred stock put option asset (in thousands): Redeemable convertible preferred stock put option: Balance at December 31, 2017 $ — Issuance of Series B redeemable convertible preferred stock tranche put option 1,527 Settlement of redeemable convertible preferred stock tranche liability due to the issuance of Series B redeemable convertible preferred stock (1,527 ) Balance at September 30, 2018 $ — |
Summary of Changes in Fair Value of Redeemable Convertible Preferred Stock Tranche Liability | The following table sets forth a summary of the changes in the fair value of the Company’s redeemable convertible preferred stock tranche liability (in thousands): Redeemable convertible preferred stock tranche liability: Balance at December 31, 2017 $ — Issuance of Series B redeemable convertible preferred stock tranche liability 2,028 Change in fair value upon revaluation (1,334 ) Settlement of redeemable convertible preferred stock tranche liability due to the issuance of Series B redeemable convertible preferred stock (694 ) Balance at September 30, 2018 $ — |
Summary of Changes in Fair Value of Redeemable Convertible Preferred Stock Warrant Liability | The following table sets forth a summary of the changes in the fair value of the Company’s redeemable convertible preferred stock warrant liability (in thousands): Redeemable convertible preferred stock warrant liability: Balance at December 31, 2017 $ — Issuance of redeemable convertible preferred stock warrant liability 878 Change in fair value upon revaluation 2,628 Reclassification of redeemable convertible preferred stock warrant liability to common stock (3,506 ) Balance at September 30, 2018 $ — |
Summary of Changes in Fair Value of Embedded Derivative in Convertible Note | The following table sets forth a summary of the changes in the fair value of the Company’s embedded derivative in convertible note (in thousands): Derivative instrument: Balance at December 31, 2017 $ — Initial fair value of the embedded derivative issued with the convertible note 4,153 Change in fair value upon revaluation — Extinguishment of the embedded derivative (4,153 ) Balance at September 30, 2018 $ — |
Condensed Balance Sheet Compo_2
Condensed Balance Sheet Components (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Balance Sheet Related Disclosures [Abstract] | |
Schedule of Property and Equipment, Net | Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2018 2017 Leasehold improvements $ 86 $ 77 Computer equipment 82 29 Office furniture and equipment 94 12 Total Property and equipment, cost 262 118 Less: Accumulated depreciation and amortization (44 ) (4 ) Property and equipment, net $ 218 $ 114 |
Schedule of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2018 2017 Accrued research and development costs $ 2,203 $ 564 Accrued employee related expenses 725 606 Liability for unvested stock, short-term 135 109 Accrued other current liabilities 364 21 $ 3,427 $ 1,300 |
Related Party Transactions (Tab
Related Party Transactions (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
BridgeBio Pharma LLC | |
Related Party Transaction [Line Items] | |
Schedule of Expenses (Benefit) from Transactions with Related Party | The Company incurred the following expenses under the agreement with BBP LLC (in thousands): Three-Month Nine-Month Periods Ended September 30, September 30, 2018 2017 2018 2017 Rent $ 14 $ 25 $ 33 $ 50 Facility 20 21 125 34 Consulting 108 167 769 367 $ 142 $ 213 $ 927 $ 451 |
Founders | |
Related Party Transaction [Line Items] | |
Schedule of Expenses (Benefit) from Transactions with Related Party | The Company incurred the following expenses (benefit) for services under the consulting agreements and stock-based compensation (in thousands): Three-Month Periods Ended Nine-Month Periods Ended September 30, September 30, 2018 2017 2018 2017 Dr. Graef $ (180 ) $ 40 $ 602 $ 124 Dr. Alhamadsheh (189 ) 31 575 98 $ (369 ) $ 71 $ 1,177 $ 222 |
Stockholders' Equity and Stoc_2
Stockholders' Equity and Stock-Based Compensation (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Stock Option Activity | The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2018: Weighted-Average Weighted-Average Aggregate Options Exercise Remaining Intrinsic Available for Options Price Per Contractual Value Grant Outstanding Share Term (years) (in thousands) Outstanding—December 31, 2017 670,996 846,164 $ 0.59 $ 4,383 Options granted (399,074 ) 399,074 $ 5.03 Options cancelled 321,916 (321,916 ) $ 0.59 Options retired (593,838 ) — $ - Additional authorized 598,000 — $ - Options granted (283,808 ) 283,808 $ 18.64 Options exercised — (149,350 ) $ 1.70 Exercised options repurchased 40,366 — $ 0.33 Options canceled 16,446 (16,446 ) $ 0.59 Outstanding—September 30, 2018 371,004 1,041,334 $ 7.05 9.46 $ 3,051 Options exercisable – September 30, 2018 153,813 $ 1.02 9.19 $ 1,378 Options vested and expected to vest – September 30, 2018 1,041,334 $ 7.05 9.46 $ 3,051 |
Schedule of Total Stock-based Compensation Expense Related to Stock-based Awards | Total stock-based compensation expense related to all our stock-based awards was recorded on the statements of operations as follows (in thousands): Three-Month Periods Ended Nine-Month Periods Ended September 30, September 30, 2018 2017 2018 2017 Research and development $ (187 ) $ 26 $ 2,016 $ 100 General and administrative 443 1 627 2 Total stock-based compensation expense $ 256 $ 27 $ 2,643 $ 102 |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Earnings Per Share [Abstract] | |
Computation of Basic and Diluted Net Loss per Share | The following table sets forth the computation of basic and diluted net loss per share (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 $ (10,176 ) $ (2,773 ) $ (36,376 ) $ (6,830 ) Denominator: Weighted-average shares used to compute net loss per common share, basic and diluted 35,591,518 3,752,883 15,976,228 3,504,790 Net loss per shares, basic and diluted $ (0.29 ) $ (0.74 ) $ (2.28 ) $ (1.95 ) |
Schedule of Shares of Potentially Dilutive Securities Excluded from Diluted Net Loss per Share Computations | The following shares of potentially dilutive securities have been excluded from the diluted net loss per share computations for the three and nine months ended September 30, 2018 and 2017 because their inclusion would be anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Redeemable convertible preferred stock on an as-converted basis — 15,376,164 — 15,376,164 Options to purchase common stock 1,041,334 100,719 1,041,334 100,719 Common stock subject to vesting or repurchase 988,238 424,475 988,238 424,475 2,029,572 15,901,358 2,029,572 15,901,358 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 9 Months Ended |
Sep. 30, 2018 | |
Commitments And Contingencies Disclosure [Abstract] | |
Schedule of Future Minimum Lease Payments | Future minimum lease payments as of September 30, 2018 are as follows (in thousands): Operating Year Lease Commitments 2018 (remaining three months) $ 80 2019 327 2020 337 2021 347 2022 327 $ 1,418 |
Organization and Description _2
Organization and Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands | Jun. 22, 2018USD ($)$ / sharesshares | Jun. 07, 2018shares | Sep. 30, 2018USD ($)shares | Sep. 30, 2017USD ($) | Sep. 30, 2018USD ($)Segmentshares | Sep. 30, 2017USD ($) | Jun. 06, 2018shares | Dec. 31, 2017USD ($)shares | Dec. 31, 2016USD ($) |
Organization And Description Of Business [Line Items] | |||||||||
Entity date of incorporation | Aug. 6, 2013 | ||||||||
Entity incorporation, State | Delaware | ||||||||
Number of operating segment | Segment | 1 | ||||||||
Description of stock split | 1.196-for-1 ratio | ||||||||
Stock split, conversion ratio | 1.196 | ||||||||
Common stock, shares authorized | 32,292,000 | 150,000,000 | 150,000,000 | 27,000,000 | 20,000,000 | ||||
Redeemable convertible preferred stock, shares outstanding | 0 | 0 | 12,856,325 | ||||||
Proceeds from issuance of initial public offering, net of underwriting discounts and commissions | $ | $ 110,970 | ||||||||
Net loss | $ | $ (10,176) | $ (2,773) | (36,376) | $ (6,830) | |||||
Accumulated deficit | $ | (50,908) | (50,908) | $ (14,532) | ||||||
Cash and cash equivalents | $ | $ 166,568 | $ 8,800 | $ 166,568 | $ 8,800 | $ 5,497 | $ 1,956 | |||
Common Stock | |||||||||
Organization And Description Of Business [Line Items] | |||||||||
Proceeds from issuance of initial public offering, net of underwriting discounts and commissions | $ | $ 111,000 | ||||||||
Initial Public Offering | |||||||||
Organization And Description Of Business [Line Items] | |||||||||
Redeemable convertible preferred stock, shares outstanding | 0 | ||||||||
Initial Public Offering | Common Stock | |||||||||
Organization And Description Of Business [Line Items] | |||||||||
Number of shares issued | 7,187,500 | ||||||||
Shares issued price per share | $ / shares | $ 17 | ||||||||
Redeemable convertible preferred stock and warrants converted to common stock | 29,564,527 | ||||||||
Overallotment Option | Common Stock | |||||||||
Organization And Description Of Business [Line Items] | |||||||||
Number of shares issued | 937,500 |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) | Sep. 30, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Dec. 31, 2016 |
Accounting Policies [Abstract] | ||||
Cash equivalents | $ 0 | |||
Cash and cash equivalents | $ 166,568,000 | $ 5,497,000 | $ 8,800,000 | $ 1,956,000 |
Fair Value Measurement - Additi
Fair Value Measurement - Additional Information (Details) - USD ($) | 9 Months Ended | 12 Months Ended |
Sep. 30, 2018 | Dec. 31, 2017 | |
Fair Value Disclosures [Abstract] | ||
Financial assets outside of cash in operating account | $ 0 | $ 0 |
Fair value assets, level 1 to level 2 transfers, amount | 0 | 0 |
Fair value assets, level 2 to level 1 transfers, amount | 0 | 0 |
Fair value assets transfers into Level 3 | 0 | 0 |
Fair value assets transfers out of Level 3 | 0 | 0 |
Financial liabilities, fair value | 0 | 0 |
Fair value liabilities, level 1 to level 2 transfers, amount | 0 | 0 |
Fair value liabilities, level 2 to level 1 transfers, amount | 0 | 0 |
Fair value liabilities transfers into Level 3 | 0 | 0 |
Fair value liabilities transfers out of Level 3 | $ 0 | $ 0 |
Fair Value Measurement - Summar
Fair Value Measurement - Summary of Changes in Fair Value of Redeemable Convertible Preferred Stock Put Option Asset (Details) - Fair Value, Measurements, Recurring - Redeemable Convertible Preferred Stock Put Option Asset $ in Thousands | 9 Months Ended |
Sep. 30, 2018USD ($) | |
Redeemable convertible preferred stock put option: | |
Issuance of Series B redeemable convertible preferred stock tranche put option | $ 1,527 |
Settlement of redeemable convertible preferred stock tranche liability due to the issuance of Series B redeemable convertible preferred stock | $ (1,527) |
Fair Value Measurement - Summ_2
Fair Value Measurement - Summary of Changes in Fair Value of Redeemable Convertible Preferred Stock Tranche Liability (Details) - Fair Value, Measurements, Recurring - Redeemable Convertible Preferred Stock Tranche Liability $ in Thousands | 9 Months Ended |
Sep. 30, 2018USD ($) | |
Redeemable convertible preferred stock tranche/warrant liability: | |
Issuance of Series B redeemable convertible preferred stock tranche liability | $ 2,028 |
Change in fair value upon revaluation | (1,334) |
Settlement of redeemable convertible preferred stock tranche liability due to the issuance of Series B redeemable convertible preferred stock | $ (694) |
Fair Value Measurement - Summ_3
Fair Value Measurement - Summary of Changes in Fair Value of Redeemable Convertible Preferred Stock Warrant Liability (Details) - Fair Value, Measurements, Recurring - Redeemable Convertible Preferred Stock Warrant Liability $ in Thousands | 9 Months Ended |
Sep. 30, 2018USD ($) | |
Redeemable convertible preferred stock tranche/warrant liability: | |
Issuance of redeemable convertible preferred stock warrant liability | $ 878 |
Change in fair value upon revaluation | 2,628 |
Reclassification of redeemable convertible preferred stock warrant liability to common stock | $ (3,506) |
Fair Value Measurement - Summ_4
Fair Value Measurement - Summary of Changes in Fair Value of Embedded Derivative in Convertible Note (Details) $ in Thousands | 9 Months Ended |
Sep. 30, 2018USD ($) | |
Derivative instrument: | |
Embedded derivative liability, valuation technique [extensible list] | us-gaap:ValuationTechniqueDiscountedCashFlowMember |
Embedded derivative liability, type [extensible list] | eidx:ConvertibleNoteMember |
Initial fair value of the embedded derivative issued with the convertible note | $ 4,153 |
Extinguishment of the embedded derivative | $ (4,153) |
Condensed Balance Sheet Compo_3
Condensed Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Property Plant And Equipment [Line Items] | ||
Total Property and equipment, cost | $ 262 | $ 118 |
Less: Accumulated depreciation and amortization | (44) | (4) |
Property and equipment, net | 218 | 114 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Total Property and equipment, cost | 86 | 77 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Total Property and equipment, cost | 82 | 29 |
Office Furniture and Equipment | ||
Property Plant And Equipment [Line Items] | ||
Total Property and equipment, cost | $ 94 | $ 12 |
Condensed Balance Sheet Compo_4
Condensed Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | |
Condensed Balance Sheet Components [Line Items] | |||||
Depreciation and amortization | $ 16 | $ 1 | $ 40 | $ 2 | |
Other Liabilities | |||||
Condensed Balance Sheet Components [Line Items] | |||||
Other liabilities related to long-term liability for unvested stock | $ 286 | $ 286 | $ 208 |
Condensed Balance Sheet Compo_5
Condensed Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017 |
Accrued Liabilities And Other Liabilities [Abstract] | ||
Accrued research and development costs | $ 2,203 | $ 564 |
Accrued employee related expenses | 725 | 606 |
Liability for unvested stock, short-term | 135 | 109 |
Accrued other current liabilities | 364 | 21 |
Accrued other current liabilities | $ 3,427 | $ 1,300 |
Convertible Promissory Notes -
Convertible Promissory Notes - Additional Information (Details) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended | |
Mar. 31, 2018USD ($)shares$ / shares | Feb. 28, 2018USD ($)ConvertiblePromissoryNote$ / shares | Sep. 30, 2018USD ($) | Sep. 30, 2018USD ($) | Dec. 31, 2017USD ($) | |
Short Term Debt [Line Items] | |||||
Debt discount | $ 713,000 | ||||
Loss on extinguishment of debt | $ 0 | $ 6,677,000 | |||
Series B Redeemable Convertible Preferred Stock | |||||
Short Term Debt [Line Items] | |||||
Warrant exercise price per share | $ / shares | $ 10.8348 | ||||
Debt instrument, converted into number of shares | shares | 1,324,823 | ||||
Debt instrument conversion price | $ / shares | $ 7.5844 | ||||
Warrants to purchase shares | shares | 369,180 | ||||
Convertible Promissory Notes | |||||
Short Term Debt [Line Items] | |||||
Outstanding principal and accrued interest | $ 10,000,000 | ||||
Note and Warrant Purchase Agreement | BBP LLC and Stanford University | |||||
Short Term Debt [Line Items] | |||||
Number of convertible promissory notes issued | ConvertiblePromissoryNote | 2 | ||||
Note and Warrant Purchase Agreement | BBP LLC and Stanford University | Series Seed Redeemable Convertible Preferred Stock | |||||
Short Term Debt [Line Items] | |||||
Warrants issued upon purchase of preferred stock under equity financing | $ 4,000,000 | ||||
Warrant exercise price per share | $ / shares | $ 1.3248 | ||||
Note and Warrant Purchase Agreement | BBP LLC and Stanford University | Convertible Promissory Notes | |||||
Short Term Debt [Line Items] | |||||
Aggregate principal amount | $ 10,000,000 | ||||
Debt instrument, maturity date description | The notes had a maturity date of the earliest of a qualified financing, a deemed liquidation event, a qualified initial public offering or February 2019. | ||||
Debt instrument, maturity month and year | 2019-02 | ||||
Debt instrument, annual interest rate | 5.00% | ||||
Debt instrument, convertible discount percentage | 30.00% | ||||
Fair value of warrants recorded as debt discount and redeemable convertible preferred stock warrant liability | $ 877,000 | ||||
Fair value of embedded derivative liability at issuance | 4,200,000 | ||||
Interest expense related to accrued interest and amortization of debt discount | 0 | $ 761,000 | $ 0 | ||
Debt instrument, beneficial conversion feature | $ 2,400,000 | ||||
Debt instrument, original term | 1 year | ||||
Debt discount | $ 0 | $ 228,000 | $ 0 | ||
Note and Warrant Purchase Agreement | BBP LLC and Stanford University | Convertible Promissory Notes | Minimum | |||||
Short Term Debt [Line Items] | |||||
Debt instrument convertible into future preferred stock under preferred equity financing | $ 10,000,000 | ||||
Debt instrument convertible into common stock under initial public offering | $ 30,000,000 |
Related Party Transactions - Ad
Related Party Transactions - Additional Information (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended | |||
May 31, 2018 | Dec. 31, 2017 | Aug. 31, 2016 | Apr. 30, 2016 | Sep. 30, 2018 | Sep. 30, 2018 | |
2018 Plan | Dr. Huh | ||||||
Related Party Transaction [Line Items] | ||||||
Number of options granted | 83,720 | |||||
Option vesting period | 3 years | |||||
Expense related to these awards | $ 75,000 | $ 85,000 | ||||
Dr. Graef Consulting Agreement | ||||||
Related Party Transaction [Line Items] | ||||||
Consulting agreement term | 4 years | |||||
Consulting agreement termination notice period | 30 days | |||||
Issue of shares of common stock | 195,273 | |||||
Gross-up payment due to related party | $ 83,073 | |||||
Dr. Graef Consulting Agreement | Maximum | ||||||
Related Party Transaction [Line Items] | ||||||
Annual fee amount | $ 150,000 | |||||
Dr. Alhamadsheh Consulting Agreement | ||||||
Related Party Transaction [Line Items] | ||||||
Consulting agreement term | 4 years | |||||
Consulting agreement termination notice period | 30 days | |||||
Issue of shares of common stock | 195,273 | |||||
Gross-up payment due to related party | $ 83,073 | |||||
Dr. Alhamadsheh Consulting Agreement | Maximum | ||||||
Related Party Transaction [Line Items] | ||||||
Annual fee amount | $ 115,000 | |||||
BridgeBio Pharma LLC | ||||||
Related Party Transaction [Line Items] | ||||||
Outstanding receivable | 67,000 | 29,000 | 29,000 | |||
Outstanding liability | $ 372,000 | $ 206,000 | $ 206,000 | |||
BridgeBio Pharma LLC and its Affiliates | ||||||
Related Party Transaction [Line Items] | ||||||
Ownership percentage | 75.00% | 53.00% | 53.00% |
Related Party Transactions - Sc
Related Party Transactions - Schedule of Expenses under the Agreement (Details) - BridgeBio Pharma LLC - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Related Party Transaction [Line Items] | ||||
Related party transaction expenses | $ 142 | $ 213 | $ 927 | $ 451 |
Rent | ||||
Related Party Transaction [Line Items] | ||||
Related party transaction expenses | 14 | 25 | 33 | 50 |
Facility | ||||
Related Party Transaction [Line Items] | ||||
Related party transaction expenses | 20 | 21 | 125 | 34 |
Consulting | ||||
Related Party Transaction [Line Items] | ||||
Related party transaction expenses | $ 108 | $ 167 | $ 769 | $ 367 |
Related Party Transactions - _2
Related Party Transactions - Schedule of Expenses (Benefit) for Services under Consulting Agreements and Stock-Based Compensation (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Dr. Graef | ||||
Related Party Transaction [Line Items] | ||||
Related party transaction expenses (benefit) | $ (180) | $ 40 | $ 602 | $ 124 |
Dr. Alhamadsheh | ||||
Related Party Transaction [Line Items] | ||||
Related party transaction expenses (benefit) | (189) | 31 | 575 | 98 |
Founders | ||||
Related Party Transaction [Line Items] | ||||
Related party transaction expenses (benefit) | $ (369) | $ 71 | $ 1,177 | $ 222 |
Redeemable Convertible Prefer_3
Redeemable Convertible Preferred Stock - Additional Information (Details) - USD ($) | Mar. 29, 2018 | May 31, 2018 | Mar. 31, 2018 | Sep. 30, 2018 | Sep. 30, 2017 | Jun. 22, 2018 | Dec. 31, 2017 |
Temporary Equity [Line Items] | |||||||
Proceeds from issuance of redeemable convertible preferred stock | $ 63,875,000 | $ 12,993,000 | |||||
Financial liabilities, fair value | $ 0 | $ 0 | |||||
Number of common stock issued upon conversion of redeemable convertible preferred stock | 24,025,270 | ||||||
Redeemable convertible preferred stock, shares outstanding | 0 | 12,856,325 | |||||
Series B Redeemable Convertible Preferred Stock | |||||||
Temporary Equity [Line Items] | |||||||
Redeemable convertible preferred stock issued | 4,430,162 | 1,476,715 | |||||
Proceeds from issuance of redeemable convertible preferred stock | $ 16,000,000 | $ 48,000,000 | $ 16,000,000 | ||||
Additional redeemable convertible preferred stock issuable | 4,430,162 | ||||||
Financial liabilities, fair value | $ 2,000,000 | ||||||
Redeemable convertible preferred stock purchase price per share | $ 10.8348 | $ 10.8348 | |||||
Series B Redeemable Convertible Preferred Stock | Put Option | |||||||
Temporary Equity [Line Items] | |||||||
Fair value of asset | $ 1,500,000 |
Redeemable Convertible Prefer_4
Redeemable Convertible Preferred Stock Tranche Liability and Put Option Asset - Additional Information (Details) - USD ($) | Mar. 29, 2018 | May 31, 2018 | Mar. 31, 2018 | Sep. 30, 2018 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 |
Temporary Equity [Line Items] | |||||||
Proceeds from issuance of redeemable convertible preferred stock | $ 63,875,000 | $ 12,993,000 | |||||
Shares issued upon conversion of outstanding convertible promissory note | 1,324,823 | ||||||
Conversion of convertible promissory note principal balance | $ 10,000,000 | ||||||
Fair value of tranche liability | $ 0 | 0 | $ 0 | ||||
Settlement of fair value of redeemable convertible preferred stock liability | $ 700,000 | ||||||
Black-Scholes Option Pricing Model | Term | |||||||
Temporary Equity [Line Items] | |||||||
Preferred stock liability and put option asset, fair value assumptions, measurement input, term | 29 days | ||||||
Black-Scholes Option Pricing Model | Risk-Free Interest Rate | |||||||
Temporary Equity [Line Items] | |||||||
Preferred stock liability and put option asset, fair value assumptions, measurement input | 1.63% | ||||||
Black-Scholes Option Pricing Model | Volatility | |||||||
Temporary Equity [Line Items] | |||||||
Preferred stock liability and put option asset, fair value assumptions, measurement input | 36.40% | ||||||
Black-Scholes Option Pricing Model | Dividend Yield | |||||||
Temporary Equity [Line Items] | |||||||
Preferred stock liability and put option asset, fair value assumptions, measurement input | 0.00% | ||||||
Series B Redeemable Convertible Preferred Stock | |||||||
Temporary Equity [Line Items] | |||||||
Redeemable convertible preferred stock issued | 4,430,162 | 1,476,715 | |||||
Redeemable convertible preferred stock purchase price per share | $ 10.8348 | $ 10.8348 | |||||
Proceeds from issuance of redeemable convertible preferred stock | $ 16,000,000 | $ 48,000,000 | $ 16,000,000 | ||||
Additional shares issuable upon achievement of certain milestone | 4,430,162 | ||||||
Fair value of tranche liability | $ 2,000,000 | ||||||
Remeasurement of redeemable convertible preferred stock liability | $ 700,000 | ||||||
Change in fair value of redeemable convertible preferred stock liability | $ 0 | $ 1,300,000 | |||||
Series B Redeemable Convertible Preferred Stock | Put Option | |||||||
Temporary Equity [Line Items] | |||||||
Fair value of asset | $ 1,500,000 | ||||||
Series B Redeemable Convertible Preferred Stock | Maximum | |||||||
Temporary Equity [Line Items] | |||||||
Redeemable convertible preferred stock issued | 1,476,715 | 7,231,700 |
Stockholders' Equity and Stoc_3
Stockholders' Equity and Stock-Based Compensation - Additional Information (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
May 31, 2018 | Apr. 30, 2016 | Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Stock repurchase right | 988,238 | 988,238 | 1,219,389 | ||||
Common stock, shares outstanding | 36,711,661 | 36,711,661 | 5,137,771 | ||||
Share-based compensation (benefit) expense | $ 256,000 | $ 27,000 | $ 2,643,000 | $ 102,000 | |||
Accrued Expenses and Other Current Liabilities | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Accrued repurchase liability for common stock early exercises | $ 421,000 | $ 421,000 | $ 317,000 | ||||
Stock Options | Employees | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Weighted-average grant date fair value of common stock options granted per share | $ 13.18 | ||||||
Restricted Stock | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Issuance of common stock to founders in connection with anti-dilution rights | 390,546 | ||||||
Consideration for common stock to founders in connection with anti-dilution rights | $ 0 | ||||||
Percentage of shares issued under license agreement to issue additional common stock | 1.00% | ||||||
Percentage of right lapses as shares vest | 25.00% | ||||||
Common stock, shares outstanding | 292,910 | 292,910 | 390,546 | ||||
Share-based compensation (benefit) expense | $ (400,000) | $ 0 | $ 1,000,000 | $ 0 | |||
2016 Equity Incentive Plan | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Term of options | 10 years | ||||||
2016 Equity Incentive Plan | Incentive Stock Options | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentag of exercise price of stock option granted to employee | 10.00% | ||||||
2016 Equity Incentive Plan | Minimum | Incentive Stock Options and Nonqualified Stock Options | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentage of exercise price of stock option on estimated fair value of shares | 100.00% | ||||||
2016 Equity Incentive Plan | Minimum | Incentive Stock Options | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentage of exercise price of stock option on estimated fair value of shares | 110.00% | ||||||
2018 Stock Option and Incentive Plan | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Vesting period of options | 3 years | ||||||
Common stock reserved for issuance | 598,000 | 598,000 | 598,000 | ||||
Minimum combined voting power require to grant options | 10.00% | ||||||
2018 Stock Option and Incentive Plan | Stockholders Possessing more than 10% | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Term of options | 10 years | ||||||
2018 Stock Option and Incentive Plan | Minimum | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentage of exercise price of stock option on estimated fair value of shares | 100.00% | ||||||
2018 Stock Option and Incentive Plan | Minimum | Stockholders Possessing more than 10% | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentage of exercise price of stock option on estimated fair value of shares | 110.00% | ||||||
2018 Stock Option and Incentive Plan | Maximum | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Term of options | 10 years | ||||||
2018 Employee Stock Purchase Plan | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentage of exercise price of stock option on estimated fair value of shares | 85.00% | ||||||
Common stock reserved for issuance | 143,520 | ||||||
Percentage of compensation of eligible employees to purchase shares of common stock at discount through payroll deductions | 20.00% | ||||||
2016 and 2018 Plans | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Unrecognized stock-based compensation cost related to unvested stock | $ 11,600,000 | $ 11,600,000 | |||||
Unrecognized stock-based compensation cost, to be recognized weighted-average period | 3 years 25 days | ||||||
Annual Cliff Vesting | Restricted Stock | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Vesting period of right lapses | 1 year | ||||||
Annual Cliff Vesting | 2016 Equity Incentive Plan | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Vesting period of options | 4 years | ||||||
Annual Cliff Vesting | 2018 Stock Option and Incentive Plan | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Employee stock options vesting percentage | 25.00% | ||||||
Monthly Vesting | Restricted Stock | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Vesting period of right lapses | 36 months | ||||||
Monthly Vesting | 2016 Equity Incentive Plan | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Vesting period of options | 36 months |
Stockholders' Equity and Stoc_4
Stockholders' Equity and Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands | 9 Months Ended | |
Sep. 30, 2018 | Dec. 31, 2017 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Options Available for Grant, Outstanding, Beginning balance | 670,996 | |
Options Available for Grant, Options retired | (593,838) | |
Options Available for Grant, Additional authorized | 598,000 | |
Options Available for Grant, Exercised options repurchased | 40,366 | |
Options Available for Grant, Outstanding, Ending balance | 371,004 | |
Options Outstanding, Beginning balance | 846,164 | |
Options Outstanding, Options exercised | (149,350) | |
Options Outstanding, Ending balance | 1,041,334 | |
Options Outstanding, Options exercisable – September 30, 2018 | 153,813 | |
Options Outstanding, Options vested and expected to vest – September 30, 2018 | 1,041,334 | |
Weighted-Average Exercise Price Per Share, Beginning balance | $ 0.59 | |
Weighted-Average Exercise Price Per Share, Options Exercised | 1.70 | |
Weighted-Average Exercise Price Per Share, Exercised Options Repurchased | 0.33 | |
Weighted-Average Exercise Price Per Share, Ending balance | 7.05 | |
Weighted-Average Exercise Price Per Share, Options exercisable – September 30, 2018 | 1.02 | |
Weighted-Average Exercise Price Per Share, Options vested and expected to vest – September 30, 2018 | $ 7.05 | |
Weighted-Average Remaining Contractual Term (years), Outstanding—September 30, 2018 | 9 years 5 months 15 days | |
Weighted-Average Remaining Contractual Term (years), Options exercisable – September 30, 2018 | 9 years 2 months 8 days | |
Weighted-Average Remaining Contractual Term (years), Options vested and expected to vest – September 30, 2018 | 9 years 5 months 15 days | |
Aggregate Intrinsic Value, Outstanding, Beginning balance | $ 3,051 | $ 4,383 |
Aggregate Intrinsic Value, Options exercisable – September 30, 2018 | 1,378 | |
Aggregate Intrinsic Value, Options vested and expected to vest – September 30, 2018 | $ 3,051 | |
2016 Equity Incentive Plan | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Options Available for Grant, Options granted | (399,074) | |
Options Available for Grant, Options cancelled | 321,916 | |
Options Outstanding, Options granted | 399,074 | |
Options Outstanding, Options cancelled | (321,916) | |
Weighted-Average Exercise Price Per Share, Options granted | $ 5.03 | |
Weighted-Average Exercise Price Per Share, Options Cancelled | $ 0.59 | |
2018 Stock Option and Incentive Plan | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Options Available for Grant, Options granted | (283,808) | |
Options Available for Grant, Options cancelled | 16,446 | |
Options Outstanding, Options granted | 283,808 | |
Options Outstanding, Options cancelled | (16,446) | |
Weighted-Average Exercise Price Per Share, Options granted | $ 18.64 | |
Weighted-Average Exercise Price Per Share, Options Cancelled | $ 0.59 |
Stockholders' Equity and Stoc_5
Stockholders' Equity and Stock-Based Compensation - Schedule of Total Stock-based Compensation Expense Related to Stock-based Awards (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 (benefit) expense | $ 256 | $ 27 | $ 2,643 | $ 102 |
Research and Development | ||||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation (benefit) expense | (187) | 26 | 2,016 | 100 |
General and Administrative | ||||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||||
Total stock-based compensation (benefit) expense | $ 443 | $ 1 | $ 627 | $ 2 |
Net Loss per Share - Computatio
Net Loss per Share - Computation 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 | $ (10,176) | $ (2,773) | $ (36,376) | $ (6,830) |
Denominator: | ||||
Weighted-average shares used to compute net loss per common share, basic and diluted | 35,591,518 | 3,752,883 | 15,976,228 | 3,504,790 |
Net loss per shares, basic and diluted | $ (0.29) | $ (0.74) | $ (2.28) | $ (1.95) |
Net Loss per Share - Schedule o
Net Loss per Share - Schedule of Shares of Potentially Dilutive Securities Excluded from Diluted Net Loss per Share Computations (Detail) - 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] | ||||
Antidilutive securities excluded from calculation of net loss per share | 2,029,572 | 15,901,358 | 2,029,572 | 15,901,358 |
Redeemable Convertible Preferred Stock | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Antidilutive securities excluded from calculation of net loss per share | 15,376,164 | 15,376,164 | ||
Options to Purchase Common Stock | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Antidilutive securities excluded from calculation of net loss per share | 1,041,334 | 100,719 | 1,041,334 | 100,719 |
Common Stock Subject to Vesting or Repurchase | ||||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||||
Antidilutive securities excluded from calculation of net loss per share | 988,238 | 424,475 | 988,238 | 424,475 |
License Agreement - Additional
License Agreement - Additional Information (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended | ||||
Mar. 31, 2018 | Apr. 30, 2016 | Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||||||
Research and development expense | $ 7,931,000 | $ 2,283,000 | $ 21,362,000 | $ 5,583,000 | ||||
License Agreement | Stanford University | ||||||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||||||
Shares issued price per share | $ 0.18 | |||||||
Research and development expense | $ 0 | $ 0 | $ 63,000 | $ 10,000 | $ 8,000 | |||
Maximum potential payments upon achievement of specific intellectual property, clinical and regulatory milestone events and royalties payment on net sales | $ 1,000,000 | |||||||
Period of annual decrease in license obligation amount due | 3 years | |||||||
License fees recognized upon achievement of development milestone | $ 50,000 | |||||||
License Agreement | Stanford University | Common Stock | ||||||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||||||
Shares issued | 56,809 | |||||||
Research and Development | License Agreement | Stanford University | ||||||||
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] | ||||||||
Upfront license payment amount | $ 25,000 | |||||||
License fee paid | $ 10,000 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Details) - USD ($) | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | |
Commitments And Contingencies [Line Items] | ||||
Rent expense | $ 107,000 | $ 29,000 | $ 311,000 | $ 54,000 |
Laboratory Facilities | San Francisco, California | ||||
Commitments And Contingencies [Line Items] | ||||
Operating lease, term of contract | 1 year | 1 year | ||
Operating lease, expiration period | 2022-11 | |||
Other Assets | ||||
Commitments And Contingencies [Line Items] | ||||
Security deposit for lease | $ 158,000 | $ 158,000 |
Commitments and Contingencies_2
Commitments and Contingencies - Schedule of Future Minimum Lease Payments (Details) $ in Thousands | Sep. 30, 2018USD ($) |
Commitments And Contingencies Disclosure [Abstract] | |
2018 (remaining three months) | $ 80 |
2,019 | 327 |
2,020 | 337 |
2,021 | 347 |
2,022 | 327 |
Total Operating Lease Commitments | $ 1,418 |