Entity Central Index Key Accreted liability for final payment fee. Debt instrument carrying amount including unaccreted liability for final payment fee. Unaccreted liability for final payment fee. Cover [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Shell Company Entity Shell Company Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Ex Transition Period Entity Ex Transition Period Trading Symbol Trading Symbol Title of 12(b) Security Security12b Title Security Exchange Name Security Exchange Name Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address Address Line1 Entity Address, Address Line Two Entity Address Address Line2 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Statement Of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Short-term investments Available For Sale Securities Debt Securities Current Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Total current assets Assets Current Property and equipment, net Property Plant And Equipment Net Other assets Other Assets Noncurrent Total assets Assets Liabilities and stockholders' equity Liabilities And Stockholders Equity [Abstract] Current liabilities: Liabilities Current [Abstract] Accounts payable Accounts Payable Current Accrued expenses Accrued Liabilities Current Current portion of long-term notes payable Notes Payable Current Total current liabilities Liabilities Current Long-term notes payable Long Term Notes Payable Other non-current liabilities Other Liabilities Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments And Contingencies Stockholders' equity: Stockholders Equity [Abstract] Common stock, $0.0001 par value; 200,000,000 shares authorized; 24,724,544 and 17,425,654 shares issued and outstanding as of September 30, 2020 and December 31, 2019, respectively Common Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated other comprehensive (loss) income Accumulated Other Comprehensive Income Loss Net Of Tax Accumulated deficit Retained Earnings Accumulated Deficit Total stockholders' equity Stockholders Equity Total liabilities and stockholders' equity Liabilities And Stockholders Equity Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Income Statement [Abstract] Operating expenses: Operating Expenses [Abstract] Research and development Research And Development Expense General and administrative General And Administrative Expense Total operating expenses Operating Expenses Loss from operations Operating Income Loss Other (expense) income, net: Nonoperating Income Expense [Abstract] Interest expense Interest Expense Debt Interest income Investment Income Interest Other income (expense), net Other Nonoperating Income Expense Total other (expense) income, net Nonoperating Income Expense Net loss Net Income Loss Other comprehensive (loss) income, net: Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent [Abstract] Unrealized (loss) gain on available-for-sale securities, net Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax Foreign currency translation (loss) gain Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax Total other comprehensive (loss) income, net Other Comprehensive Income Loss Net Of Tax Comprehensive loss Comprehensive Income Net Of Tax Net loss per share, basic and diluted Earnings Per Share Basic And Diluted Weighted-average common shares outstanding, basic and diluted Weighted Average Number Of Share Outstanding Basic And Diluted Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid In Capital [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income [Member] Accumulated Deficit Retained Earnings [Member] Sale of Stock Subsidiary Sale Of Stock [Axis] Sale of Stock Sale Of Stock Name Of Transaction [Domain] At-the-market offering. ATM Facility A T M [Member] Statement [Line Items] Statement [Line Items] Balance Balance, Shares Shares Issued Issuance of common stock Stock Issued During Period Value New Issues Issuance of common stock, Shares Stock Issued During Period Shares New Issues Issuance of common stock pursuant to employeestock purchase plan Stock Issued During Period Value Employee Stock Purchase Plan Issuance of common stock pursuant to employee stock purchase plan, Shares Stock Issued During Period Shares Employee Stock Purchase Plans Vesting of restricted stock liability Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition Stock-based compensation expense Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Issuance of common stock warrants Adjustments To Additional Paid In Capital Warrant Issued Other comprehensive income (loss) Net loss Balance Balance, Shares Non cash consulting expense. Equity issuance costs in accounts payable. Fair value of common stock warrants in connection with issuance of notes payable. Statement Of Cash Flows [Abstract] Counterparty Name Counterparty Name [Axis] Counterparty Name Repurchase Agreement Counterparty Name [Domain] Lincoln Park Capital Fund, LLC. Lincoln Park Capital Fund, LLC Lincoln Park Capital Fund L L C [Member] Operating activities: Net Cash Provided By Used In Operating Activities [Abstract] Net loss Profit Loss Adjustments to reconcile net loss to cash used in operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Depreciation and amortization Depreciation And Amortization Stock-based compensation Share Based Compensation Net unrealized (gain) loss on foreign currency transactions Foreign Currency Transaction Gain Loss Unrealized Non-cash consulting expense Non Cash Consulting Expense Amortization of term loan discount and issuance costs Amortization Of Financing Costs And Discounts Realized gain on investments Gain On Sale Of Investments Amortization/accretion of investments, net Accretion Amortization Of Discounts And Premiums Investments Changes in operating assets and liabilities: Increase Decrease In Operating Capital [Abstract] Prepaid expenses and other current assets Increase Decrease In Prepaid Deferred Expense And Other Assets Accounts payable Increase Decrease In Accounts Payable Accrued expenses Increase Decrease In Accrued Liabilities Net cash used in operating activities Net Cash Provided By Used In Operating Activities Investing activities: Net Cash Provided By Used In Investing Activities [Abstract] Purchases of property and equipment Payments To Acquire Property Plant And Equipment Purchases of short-term investments Payments To Acquire Short Term Investments Maturities of short-term investments Proceeds From Maturities Prepayments And Calls Of Shortterm Investments Net cash (used in) provided by investing activities Net Cash Provided By Used In Investing Activities Financing activities: Net Cash Provided By Used In Financing Activities [Abstract] Proceeds from issuance of common stock, net of issuance costs Proceeds From Issuance Of Common Stock Proceeds from issuance of notes payable, net of issuance costs Proceeds From Debt Net Of Issuance Costs Proceeds from ESPP purchase Proceeds From Stock Plans Net cash provided by financing activities Net Cash Provided By Used In Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Net increase (decrease) in cash and cash equivalents Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Cash and cash equivalents at end of period Supplemental disclosures of non-cash activities: Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Issuance of commitment shares to Lincoln Park pursuant to agreement Stock Issued1 Equity issuance costs in accounts payable Equity Issuance Costs In Accounts Payable Fair value of common stock warrants in connection with issuance of notes payable Fair Value Of Common Stock Warrants In Connection With Issuance Of Notes Payable Notes payable issuance costs in accounts payable Debt Issuance Costs Incurred During Noncash Or Partial Noncash Transaction Organization Consolidation And Presentation Of Financial Statements [Abstract] Organization and Accounting Pronouncements Organization Consolidation And Presentation Of Financial Statements Disclosure And Significant Accounting Policies [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Fair Value Disclosures [Abstract] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Certain financial statement caption information. Certain Financial Statement Caption Information. Certain Financial Statement Caption Information [Abstract] Certain Financial Statement Caption Information Certain Financial Statement Caption Information [Text Block] Debt Disclosure [Abstract] Notes Payable Mortgage Notes Payable Disclosure [Text Block] Collaboration and license agreement. Collaboration And License Agreement [Abstract] Collaboration and License Agreement Collaborative Arrangement Disclosure [Text Block] Equity [Abstract] Stockholders’ Equity Stockholders Equity Note Disclosure [Text Block] Recently Issued Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Use of Estimates Use Of Estimates Accrued research and development expense policy. Accrued Research and Development Expense Accrued Research And Development Expense Policy [Text Block] Australian research and development tax incentive policy. Australian Research and Development Tax Incentive Australian Research And Development Tax Incentive Policy [Text Block] Stock-Based Compensation Share Based Compensation Option And Incentive Plans Policy Net Loss per Share Earnings Per Share Policy [Text Block] Summary of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Summary of Assets that Require Fair Value Measurements on Recurring Basis and Their Respective Input Levels Based on Fair Value Hierarchy Fair Value Assets Measured On Recurring Basis [Text Block] Schedule of Company's Short-Term Investments Schedule Of Cash Cash Equivalents And Short Term Investments Table [Text Block] Schedule of Accrued Expenses Schedule Of Accrued Liabilities Table [Text Block] Schedule of Aggregate Carrying Amounts of Term Loans Schedule Of Line Of Credit Facilities [Text Block] Schedule Future Maturities of Term Loans, Including Final Payment Fee Schedule Of Maturities Of Long Term Debt Table [Text Block] Summary of Stock Option Activity Schedule Of Share Based Compensation Stock Options Activity Table [Text Block] Summary of Non-cash Stock-based Compensation Expense Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Common stock reserved for future issuance. Summary of Reserved Shares of Common Stock for Future Issuance Common Stock Reserved For Future Issuance Table [Text Block] Date of incorporation Entity Incorporation Date Of Incorporation State of incorporation Cash, Cash equivalents and short-term investments Cash Cash Equivalents And Short Term Investments Foreign currency transaction net realized and unrealized gains (losses) Foreign Currency Transaction Gain Loss Before Tax Summary of significant accounting policies. Summary Of Significant Accounting Policies [Abstract] Summary of significant accounting policies. Summary of significant accounting policies. Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Minimum Minimum [Member] Maximum Maximum [Member] Income Tax Authority, Name Income Tax Authority Name [Axis] Income Tax Authority, Name Income Tax Authority Name [Domain] Australian Taxation Office Australian Taxation Office [Member] Tax Credit Carryforward Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name Tax Credit Carryforward Name [Domain] Australian research and development tax incentive program. Australian Research and Development Tax Incentive Program Australian Research And Development Tax Incentive Program [Member] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Research and development tax incentive revenue criteria. Revenue for availability of research and development tax incentive Research And Development Tax Incentive Revenue Criteria Earnings Per Share [Abstract] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Antidilutive Securities Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities Name [Domain] Common Stock Options Employee Stock Option [Member] Common Stock Warrants Warrant [Member] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Antidilutive securities not included in calculation of diluted net loss per share Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Hierarchy and NAV Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 Fair Value Inputs Level1 [Member] Level 2 Fair Value Inputs Level2 [Member] Level 3 Fair Value Inputs Level3 [Member] Underlying Asset Class Underlying Asset Class [Axis] Underlying Asset Class Underlying Asset Class [Domain] Agency Securities Agency Securities [Member] Asset Class Fair Value By Asset Class [Axis] Asset Class Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class [Domain] U.S. Treasury Securities U S Treasury Securities [Member] Certificates of Deposit Certificates Of Deposit [Member] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Total short-term investments Investments Fair Value Disclosure Fair Value By Balance Sheet Grouping [Table] Fair Value By Balance Sheet Grouping [Table] Fair Value Measured Using Net Asset Value Fair Value Measured At Net Asset Value Per Share [Member] Cash and Cash Equivalents Cash And Cash Equivalents [Axis] Cash and Cash Equivalents Restricted Cash And Cash Equivalents Cash And Cash Equivalents [Member] Money Market Funds Money Market Funds [Member] Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items] Carrying amount of notes payable Notes Payable Investments in money market funds Money Market Funds At Carrying Value Debt Securities Available For Sale [Table] Debt Securities Available For Sale [Table] Financial Instrument Financial Instrument [Axis] Financial Instruments Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] U S Treasury Securities maturing in one year or less. U.S. Treasury Securities Maturing in One Year or Less U S Treasury Securities Maturing In One Year Or Less [Member] Agency securities maturing in one year or less. Agency Securities Maturing in One Year or Less Agency Securities Maturing In One Year Or Less [Member] Certificates of deposit maturing in one year or less. Certificates of Deposit Maturing in One Year or Less Certificates Of Deposit Maturing In One Year Or Less [Member] U S Treasury Securities maturing between one and five years. U.S. Treasury Securities Maturing between One and Five years U S Treasury Securities Maturing Between One And Five Years [Member] Certificates of deposit maturing between one and five years. Certificates of Deposit Maturing between One and Five Years Certificates Of Deposit Maturing Between One And Five Years [Member] Schedule Of Available For Sale Securities [Line Items] Schedule Of Available For Sale Securities [Line Items] Maturity (in years) Debt Securities Available For Sale Term Amortized Cost Available For Sale Debt Securities Amortized Cost Basis Unrealized Gains Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax Unrealized losses Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax Available for sale Securities debt maturities period Available For Sale Securities Debt Maturities Period Other than temporary impairment loss investments available for sale securities Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net Availableforsale Securities Realized gain on investments Realized loss on investments Loss On Sale Of Investments Accrued Clinical Studies. Accrued preclinical research. Accrued Liabilities Current [Abstract] Accrued payroll and other employee benefits Employee Related Liabilities Current Clinical studies Accrued Clinical Studies Other accruals Other Accrued Liabilities Current Accrued interest Interest Payable Current Preclinical research Accrued Preclinical Research Total accrued expenses Schedule Of Short Term Debt [Table] Schedule Of Short Term Debt [Table] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument Name [Domain] Loan Agreement. Loan Agreement Loan Agreement [Member] Term A Loan. Term A Loan Term A Loan [Member] Term B Loan. Term B Loan Term B Loan [Member] Term C Loan. Term C Loan Term C Loan [Member] Term A Loan and Term B Loan. Term A Loan & Term B Loan Term A Loan And Term B Loan [Member] Long-term Debt, Type Longterm Debt Type [Axis] Long-term Debt, Type Longterm Debt Type [Domain] Line of Credit Line Of Credit [Member] Variable Rate Variable Rate [Axis] Variable Rate Variable Rate [Domain] Prime Rate Prime Rate [Member] Measurement Input Type Measurement Input Type [Axis] Measurement Input Type Measurement Input Type [Domain] Expected Term Measurement Input Expected Term [Member] Volatility Measurement Input Price Volatility [Member] Risk Free Rate Measurement Input Risk Free Interest Rate [Member] Expected Dividend Measurement Input Expected Dividend Rate [Member] Short Term Debt [Line Items] Short Term Debt [Line Items] Borrowing capacity under loan agreement Line Of Credit Facility Maximum Borrowing Capacity Borrowings under loan agreement Line Of Credit Line of credit facility frequency of payments principal and interest. Term Loan maturity date Line Of Credit Facility Expiration Date1 Line of credit facility frequency of payments principal and interest Line Of Credit Facility Frequency Of Payments Principal And Interest Debt instrument, frequency of periodic payment Debt Instrument Frequency Of Periodic Payment Debt instrument, interest rate, stated percentage Debt Instrument Interest Rate Stated Percentage Debt instrument, interest rate, basis for effective rate Debt Instrument Interest Rate Basis For Effective Rate Debt instrument, basis spread on variable rate Debt Instrument Basis Spread On Variable Rate1 Debt instrument periodic payment terms balloon payment to be paid as percent. Required notice period for debt prepayment. Debt prepayment fee as percent on year one. Debt prepayment fee as percent on year two. Debt prepayment fee as percent from year three. Percentage of final principal payment Debt Instrument Periodic Payment Terms Balloon Payment To Be Paid As Percent Required notice period for debt prepayment Required Notice Period For Debt Prepayment Debt prepayment fee as percent on year one Debt Prepayment Fee As Percent On Year One Debt prepayment fee as percent on year two Debt Prepayment Fee As Percent On Year Two Debt prepayment fee as percent from year three Debt Prepayment Fee As Percent From Year Three Class of warrant or right value of securities called by warrants or rights as percentage of term loan. Lenders warrants exercisable for shares Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights Warrants exercisable, per share exercise price Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 Percentage of lenders additional warrants to purchase shares of company's common stock Class Of Warrant Or Right Value Of Securities Called By Warrants Or Rights As Percentage Of Term Loan Fair value of the warrants at the date of issuance Warrants Not Settleable In Cash Fair Value Disclosure Warrants and rights outstanding, measurement input Warrants And Rights Outstanding Measurement Input Debt issuance costs Deferred Finance Costs Gross Debt instrument, interest rate, effective percentage Debt Instrument Interest Rate Effective Percentage Debt Instrument [Table] Debt Instrument [Table] Debt Instrument [Line Items] Debt Instrument [Line Items] Principal Debt Instrument Carrying Amount Add: accreted liability for Final Payment fee Accreted Liability For Final Payment Fee Less: unamortized discount Debt Instrument Unamortized Discount Total Long Term Debt Debt instrument carrying amount including unaccreted liability for final payment fee maturities repayments of principal remainder of fiscal year. Debt instrument carrying amount including unaccreted liability for final payment fee maturities repayments of principal in year two. Debt instrument carrying amount including unaccreted liability for final payment fee maturities repayments of principal in year three. Debt instrument carrying amount including unaccreted liability for final payment fee maturities repayments of principal in year four. Debt instrument carrying amount including unaccreted liability for final payment fee maturities repayments of principal in year five. Remainder of 2020 Debt Instrument Carrying Amount Including Unaccreted Liability For Final Payment Fee Maturities Repayments Of Principal Remainder Of Fiscal Year Year ending December 31, 2021 Debt Instrument Carrying Amount Including Unaccreted Liability For Final Payment Fee Maturities Repayments Of Principal In Year Two Year ending December 31, 2022 Debt Instrument Carrying Amount Including Unaccreted Liability For Final Payment Fee Maturities Repayments Of Principal In Year Three Year ending December 31, 2023 Debt Instrument Carrying Amount Including Unaccreted Liability For Final Payment Fee Maturities Repayments Of Principal In Year Four Year ending December 31, 2024 Debt Instrument Carrying Amount Including Unaccreted Liability For Final Payment Fee Maturities Repayments Of Principal In Year Five Debt instrument carrying amount including unaccreted liability for final payment fee Debt Instrument Carrying Amount Including Unaccreted Liability For Final Payment Fee Unaccreted balance for Final Payment fee on Term Loans Unaccreted Liability For Final Payment Fee Less current portion Long Term Debt Current Noncurrent portion Long Term Debt Noncurrent Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Biocon. Biocon Biocon [Member] Collaborative Arrangement and Arrangement Other than Collaborative Type Of Arrangement [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Arrangements And Nonarrangement Transactions [Member] Collaboration and License Agreement Collaborative Arrangement [Member] Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Common Stock Shares Issued Regulatory milestone payments upon the achievement of certain regulatory approvals. Sales milestone payments upon the achievement of first commercial sale of product and specified levels of product sales. Regulatory milestone payments Regulatory Milestone Payments Upon Achievement Of Certain Regulatory Approvals Sales milestone payments Sales Milestone Payments Upon The Achievement Of First Commercial Sale Of Product And Specified Levels Of Product Sales Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Underwritten public offering. Underwritten Public Offering Underwritten Public Offering [Member] Over Allotment Option Over Allotment Option [Member] Open market sales agreement. Open Market Sales Agreement Open Market Sales Agreement [Member] Credit Facility Credit Facility [Axis] Credit Facility Credit Facility [Domain] Two thousand nineteen ATM Facility. 2019 ATM Facility Two Thousand Nineteen A T M Facility [Member] 2020 ATM Facility. 2020 ATM Facility Two Thousand Twenty A T M Facility [Member] Subsequent Event Type Subsequent Event Type [Axis] Subsequent Event Type Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Purchase Agreement. Purchase Agreement Purchase Agreement [Member] Valuation Approach and Technique Valuation Technique [Axis] Valuation Approach and Technique Valuation Technique [Domain] Repricing of outstanding options. Repricing of Outstanding Options Repricing Of Outstanding Options [Member] Stock Options Employee Stock [Member] Title of Individual Title Of Individual [Axis] Title of Individual Title Of Individual With Relationship To Entity [Domain] Executive chairman, chief executive officer and non-management directors. Executive Chairman, Chief Executive Officer and Non-management Directors Executive Chairman Chief Executive Officer And Non Management Directors [Member] Executive Chairman Board Of Directors Chairman [Member] Chief Executive Officer Chief Executive Officer [Member] Non Management Directors. Non-Management Directors Non Management Directors [Member] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Preferred stock, shares authorized Preferred Stock Shares Authorized Preferred stock, par value Preferred Stock Par Or Stated Value Per Share Gross proceeds from issuance of common stock. Issuance of common stock, Shares Sale of stock, price per share Shares Issued Price Per Share Gross proceeds from issuance of common stock Gross Proceeds From Issuance Of Common Stock Proceeds from issuance of common stock Commission rate. Commission rate Commission Rate Common stock shares maximum aggregate offering price. Common stock shares maximum aggregate offering price Common Stock Shares Maximum Aggregate Offering Price Stock issuance costs Payments Of Stock Issuance Costs Term of purchase agreement. Fair market value of commitment shares. Estimated maximum amount of common stock issuable. Estimated maximum amount of common stock issuable Estimated Maximum Amount Of Common Stock Issuable Term of purchase agreement Term Of Purchase Agreement Fair market value of commitment shares Fair Market Value Of Commitment Shares Repricing of outstanding options Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Exercise price of options per share Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price Unamortized stock-based compensation incremental expense on the repriced options Share Based Compensation Arrangement By Share Based Payment Award Plan Modification Incremental Compensation Cost Stock-based compensation expense Allocated Share Based Compensation Expense Stock Options Number of Shares Subject to Options, Beginning Balance Number of Shares Subject to Options, Granted Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross Number of Shares Subject to Options, Exercised Stock Issued During Period Shares Stock Options Exercised Number of Shares Subject to Options, Forfeitures and Cancellations Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period Number of Shares Subject to Options, Ending Balance Number of Shares Subject to Options, Exercisable Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number Weighted- Average Exercise Price Per Share, Beginning Balance Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price Weighted- Average Exercise Price Per Share, Granted Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price Weighted- Average Exercise Price Per Share, Exercised Weighted- Average Exercise Price Per Share, Forfeitures and Cancellations Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price Weighted- Average Exercise Price Per Share, Ending Balance Weighted- Average Exercise Price Per Share, Exercisable Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price Weighted Average Remaining Contractual Term, Options Outstanding Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 Weighted Average Remaining Contractual Term, Options Exercisable Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 Aggregate Intrinsic Value, Options Outstanding Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value Aggregate Intrinsic Value, Options Exercisable Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 Closing stock price per share Share Price Exercise price of repriced options per share Reduction in cash remuneration expressed as a percentage of the individual's base salary. Number of non-management directors. Unamortized stock compensation for stock options Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Weighted-average recognition period of stock option unamortized Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 Number of non-management directors Number Of Non Management Directors Retention stock options issued to purchase common shares Reduction in cash remuneration expressed as a percentage Reduction In Compensation Arrangement With Individual Cash Awards Granted Percentage Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Research and Development Expense Research And Development Expense [Member] General and Administrative Expense General And Administrative Expense [Member] Non-cash stock-based compensation expense Stock options issued and outstanding. Stock Options Issued and Outstanding Stock Options Issued And Outstanding [Member] Warrants for Common Stock Awards available under 2018 plan. Awards Available Under 2018 Equity Incentive Plan Awards Available Under2018 Plan [Member] Employee stock purchase plan. Employee Stock Purchase Plan Employee Stock Purchase Plan [Member] Total common stock reserved for future issuance Common Stock Capital Shares Reserved For Future Issuance