Quince Therapeutics (QNCX) 10-Q 12 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 11, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Trading Symbol	CRTX
Entity Registrant Name	Cortexyme, Inc.
Entity Central Index Key	0001662774
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		29,497,999
Entity File Number	001-38890
Entity Tax Identification Number	90-1024039
Entity Address, Address Line One	269 East Grand Ave.
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	910-5717
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $0.001 per share
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 64,246,000	$ 51,214,000
Short term investments	73,548,000	48,650,000
Prepaid expenses and other current assets	5,180,000	6,192,000
Total current assets	142,974,000	106,056,000
Property and equipment, net	500,000	709,000
Operating lease right-of-use assets, net	848,000	625,000
Long term investments	60,133,000	16,763,000
Other assets	209,000	217,000
Total assets	204,664,000	124,370,000
Current liabilities:
Accounts payable	4,309,000	3,075,000
Accrued expenses and other current liabilities	12,100,000	5,817,000
Total current liabilities	16,409,000	8,892,000
Long-term operating lease liability	244,000
Total liabilities	16,653,000	8,892,000
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000,000 authorized, no shares issued and outstanding as of September 30, 2020 and December 31, 2019
Common stock, $0.001 par value, 100,000,000 shares authorized, 29,494,249 and 26,869,413 issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	29,000	27,000
Additional paid in capital	313,568,000	185,196,000
Accumulated other comprehensive income	513,000	60,000
Accumulated deficit	(126,099,000)	(69,805,000)
Total stockholders’ equity	188,011,000	115,478,000
Total liabilities and stockholders’ equity	$ 204,664,000	$ 124,370,000

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	29,494,249	26,869,413
Common stock, shares outstanding	29,494,249	26,869,413

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development	$ 16,983	$ 8,253	$ 45,450	$ 20,187
General and administrative	4,929	2,316	12,591	6,032
Total operating expenses	21,912	10,569	58,041	26,219
Loss from operations	(21,912)	(10,569)	(58,041)	(26,219)
Interest income	406	711	1,747	1,618
Net loss	(21,506)	(9,858)	(56,294)	(24,601)
Other comprehensive income / (loss):
Unrealized gain / (loss) on available for sales securities	(198)	16	453	145
Total comprehensive loss	$ (21,704)	$ (9,842)	$ (55,841)	$ (24,456)
Net loss per share - basic and diluted	$ (0.73)	$ (0.37)	$ (1.94)	$ (1.59)
Weighted average shares of common stock outstanding - basic and diluted	29,488,739	26,841,149	29,066,006	15,489,216

Condensed Statements of Redeema

Condensed Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Private Placement	Series A Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred Stock	Common Stock	Common StockPrivate Placement	Additional Paid in Capital	Additional Paid in CapitalPrivate Placement	Other Comprehensive Income / (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ (32,626)				$ 3		$ 245		$ (49)	$ (32,825)
Beginning balance, shares at Dec. 31, 2018			9,008,919	9,152,108
Beginning balance at Dec. 31, 2018			$ 17,178	$ 86,868
Beginning balance, shares at Dec. 31, 2018					3,412,366
Exercise of stock options	69				$ 1		68
Exercise of stock options, shares					166,015
Stock based compensation	1,479						1,479
Vesting of Series B redeemable convertible preferred stock in lieu of rent				$ 948
Conversion of redeemable convertible preferred stock to common stock	104,994				$ 18		104,976
Conversion of redeemable convertible preferred stock to common stock, shares			(9,008,919)	(9,152,108)
Conversion of redeemable convertible preferred stock to common stock			$ (17,178)	$ (87,816)
Conversion of redeemable convertible preferred stock to common stock, shares					18,161,027
Issuance of common stock, net of issuance costs	77,827				$ 5		77,822
Issuance of common stock, net of issuance costs, shares					5,073,800
Exercise of stock warrant, shares					27,941
Other comprehensive income (loss)	145								145
Net loss	(24,601)									(24,601)
Ending balance at Sep. 30, 2019	127,287				$ 27		184,590		96	(57,426)
Ending balance, shares at Sep. 30, 2019					26,841,149
Beginning balance at Jun. 30, 2019	136,217				$ 27		183,678		80	(47,568)
Beginning balance, shares at Jun. 30, 2019					26,841,149
Stock based compensation	912						912
Other comprehensive income (loss)	16								16
Net loss	(9,858)									(9,858)
Ending balance at Sep. 30, 2019	127,287				$ 27		184,590		96	(57,426)
Ending balance, shares at Sep. 30, 2019					26,841,149
Beginning balance at Dec. 31, 2019	115,478				$ 27		185,196		60	(69,805)
Beginning balance, shares at Dec. 31, 2019					26,869,413
Exercise of stock options	1,235						1,235
Exercise of stock options, shares					124,836
Stock based compensation	9,511						9,511
Issuance of common stock, net of issuance costs		$ 117,628				$ 2		$ 117,626
Issuance of common stock, net of issuance costs, shares						2,500,000
Other comprehensive income (loss)	453								453
Net loss	(56,294)									(56,294)
Ending balance at Sep. 30, 2020	188,011				$ 29		313,568		513	(126,099)
Ending balance, shares at Sep. 30, 2020					29,494,249
Beginning balance at Jun. 30, 2020	205,467				$ 29		309,320		711	(104,593)
Beginning balance, shares at Jun. 30, 2020					29,486,269
Exercise of stock options	90						90
Exercise of stock options, shares					7,980
Stock based compensation	4,158						4,158
Other comprehensive income (loss)	(198)								(198)
Net loss	(21,506)									(21,506)
Ending balance at Sep. 30, 2020	$ 188,011				$ 29		$ 313,568		$ 513	$ (126,099)
Ending balance, shares at Sep. 30, 2020					29,494,249

Condensed Statements of Redee_2

Condensed Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Unaudited) (Parenthetical) - Common Stock - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Stock issuance costs		$ 8,427
Private Placement
Stock issuance costs	$ 7,372

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (56,294)	$ (24,601)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash rent expense	275	275
Stock based compensation	9,511	1,479
Depreciation and amortization	247	112
Amortization of premium (discount) on available for sale investments	429	(728)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,044	(3,281)
Other assets	8	(253)
Accounts payable	1,234	1,800
Accrued expenses and other current liabilities	6,004	2,870
Net cash used in operating activities	(37,542)	(22,327)
Cash flow from investing activities:
Purchase of investments	(183,356)	(98,475)
Proceeds from maturities of investments	115,141	63,070
Purchase of property and equipment	(42)	(46)
Net cash used in investing activities	(68,257)	(35,451)
Cash flows from financing activities:
Payments of finance leases	(32)
Proceeds from issuance of common stock upon exercise of stock options	1,235	69
Proceeds from initial public offering, net of stock offering costs		77,827
Proceeds from private placement offering, net of issuance costs	117,628
Net cash provided by financing activities	118,831	77,896
Net change in cash and cash equivalents	13,032	20,118
Cash, cash equivalents and restricted cash at beginning of period	51,214	24,872
Cash, cash equivalents and restricted cash at end of period	64,246	44,990
Supplemental disclosures of non-cash information:
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 620	878
Right-of-use assets obtained in exchange for new finance lease liabilities		500
Series A Redeemable Convertible Preferred Stock
Supplemental disclosures of non-cash information:
Conversion of redeemable convertible preferred stock to common stock on initial public offering		17,178
Series B Redeemable Convertible Preferred Stock
Supplemental disclosures of non-cash information:
Conversion of redeemable convertible preferred stock to common stock on initial public offering		87,816
Acceleration of vesting of stock on initial public offering		$ 856

Organization

Organization	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	Note 1. Organization Description of Business Cortexyme, Inc. (the “Company”) was incorporated in the State of Delaware in June 2012 and is headquartered in South San Francisco, California. The Company is a clinical stage biopharmaceutical company focused on developing therapeutics based on data supporting a new theory of the cause of Alzheimer’s disease and other degenerative disorders. Cortexyme is targeting a specific, infectious pathogen tied to neurodegeneration and chronic inflammation in humans and animal models. Initial Public Offering On May 8, 2019, the Company’s registration statement on Form S-1 (File No. 333-230853) for its initial public offering of common stock (“IPO”) was declared effective by the Securities and Exchange Commission (“SEC”). On May 13, 2019, the Company closed its IPO with the sale of 5,073,800 shares of common stock, which included 661,800 shares of common stock issued upon the exercise in full of the underwriters’ option to purchase additional shares, at a public offering price of $17.00 per share, resulting in net proceeds of $77.8 million, after deducting underwriting discounts and commissions and estimated offering expenses paid by the Company. In addition, in connection with the closing of the IPO, all of the Company’s outstanding shares of redeemable convertible preferred stock were automatically converted into 18,161,027 shares of common stock, and there are no shares of redeemable convertible preferred stock outstanding. Private Investment in Public Equity (“PIPE”) In February 2020, the Company completed a private investment in public equity transaction (“PIPE Financing”). The Company entered into Stock Purchase Agreements (the “Purchase Agreements”) with certain accredited investors, including an entity affiliated with a member of the Company’s Board of Directors, pursuant to which the Company sold and issued shares of common stock for aggregate gross proceeds of $125.0 million. Costs related to the offering were $7.4 million. Pursuant to the Purchase Agreements, the Company sold 2,500,000 common shares at $50.00 per common share. In connection with the PIPE Financing, the Company filed a registration statement on Form S-1 (File No. 333-237594), with the SEC registering for resale the shares of common stock issued in the PIPE Financing. The registration statement was declared effective by the SEC on April 13, 2020. Liquidity and Capital Resources The Company has incurred losses and negative cash flows from operations since inception and expects to continue to generate operating losses for the foreseeable future. As of September 30, 2020, the Company had an accumulated deficit of $126.1 million. Since inception through September 30, 2020, the Company has funded operations primarily with the net proceeds from the issuance of convertible promissory notes, from the issuance of redeemable convertible preferred stock, from the net proceeds from the IPO and from the net proceeds from the PIPE Financing. As of September 30, 2020, the Company had cash, cash equivalents, and short-term investments of $137.8 million, which it believes will be sufficient to fund its planned operations for a period of at least 12 months from the date of the issuance of the accompanying unaudited financial statements. The Company also has long-term investments of $60.1 million. Management expects to incur additional losses in the future to fund its operations and conduct product research and development and may need to raise additional capital to fully implement its business plan. The Company may raise additional capital through the issuance of equity securities, debt financings or other sources in order to further implement its business plan. However, if such financing is not available when needed and at adequate levels, the Company will need to reevaluate its operating plan and may be required to delay the development of its product candidate.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and pursuant to the instructions of the SEC on The condensed balance sheet as of September 30, 2020, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, the condensed statements of redeemable convertible preferred stock and stockholders’ equity for the three and nine months ended September 30, 2020 and 2019, the condensed statements of cash flows for the nine months ended September 30, 2020 and 2019, and the financial data and other financial information disclosed in the notes to the condensed financial statements are unaudited. These financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2019 included in the Company’s Form 10-K filed with the SEC on March 16, 2020. Risks and Uncertainties The pandemic caused by an outbreak of a new strain of coronavirus, COVID-19, has resulted, and is likely to continue to result, in significant national and global economic disruption and may adversely affect our business. The Company is actively monitoring the impact of COVID-19 and the possible effects on its financial condition, liquidity, operations, clinical trials, suppliers, industry and workforce. However, the full extent, consequences, and duration of the COVID-19 pandemic and the resulting impact on the Company cannot currently be predicted. The Company will continue to evaluate the impact that these events could have on the Company’s operations, financial position, and the results of operations and cash flows during fiscal year 2020 and beyond. Use of Estimates The preparation of the Company’s financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and expenses, as well as related disclosure of contingent assets and liabilities. The most significant estimates used in the Company’s financial statements relate to the determination of the fair value of common stock prior to the initial public offering, stock-based awards and other issuances, accruals for research and development costs, useful lives of long-lived assets, stock-based compensation and related assumptions, the incremental borrowing rate for leases and income tax uncertainties, including a valuation allowance for deferred tax assets; and contingencies. The Company bases its estimates on historical experience and on various other market specific and other relevant assumptions that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from the Company’s estimates. Significant Accounting Policies There have been no significant changes to the accounting policies during the nine months ended September 30, 2020, as compared to the significant accounting policies described in our Annual Report on Form 10-K. Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value. There are no unrealized gains or losses on the money market funds for the periods presented. Fair Value Measurements The fair value of our financial instruments reflects the amounts that we estimate we would receive in connection with the sale of an asset or pay in connection with the transfer of a liability in an orderly transaction between market participants at the measurement date (exit price). We disclose and recognize the fair value of our Level 1 - Inputs that reflect unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access at the measurement date; Level 2 - Inputs other than quoted prices that are observable for the assets or liability either directly or indirectly, including inputs in markets that are not considered to be active; Level 3 - Inputs that are unobservable. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update, or ASU, No. 2016-02, Leases (Topic 842), to enhance the transparency and comparability of financial reporting related to leasing arrangements. The Company adopted the standard effective January 1, 2019. The Company determines if an arrangement includes a lease at inception. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset includes any lease payments made and excludes lease incentives. Incremental borrowing rate is used in determining the present value of future payments. The Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. The lease terms may include options to extend or terminate the lease. Lease expense for minimum lease payments is recognized on a straight-line basis over the non-cancelable lease term. The Company has elected not to recognize a right-of-use asset and lease liability for short-term leases. A short-term lease is a lease with an expected lease term of 12 months or less and which does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. The Company also elected the package of practical expedients under the transition guidance that will retain the historical lease classification and initial direct costs for any leases that exist prior to adoption of the new guidance and the practical expedient to not separate lease and non-lease components. See Note 6 for further disclosure. Finance lease right of use assets are recorded on the balance sheet in Property and equipment, net. The current portion of the operating lease liability is recorded in accrued expenses and other current liabilities. Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to not use this extended transition period for complying with certain new or revised accounting standards that have different effective dates for public and private companies. Recent Accounting Pronouncements Adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. The new guidance changes disclosure requirements related to fair value measurements as part of the disclosure framework project. The disclosure framework project aims to improve the effectiveness of disclosures in the notes to the financial statements by focusing on requirements that clearly communicate the most important information to users of the financial statements. The Company adopted this effective January 1, 2020. The adoption of this pronouncement did not have a material impact on its financial statements or disclosures. In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40)”: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”), which clarifies the accounting for implementation costs in cloud computing arrangements. The Company adopted the standard prospectively on January 1, 2020. The adoption of this pronouncement did not have a material impact on its financial statements. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its financial statements: Financial Instruments—Credit Losses: In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments which amends the principles around the recognition of credit losses by mandating entities incorporate an estimate of current expected credit losses when determining the value of certain assets. The guidance also amends reporting around allowances for credit losses on available-for-sale marketable securities. For Smaller Reporting Companies as defined by the SEC, ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. The Company is evaluating the impact of the guidance on its financial statements. All other newly issued accounting pronouncements not yet effective have been deemed either immaterial or not applicable.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements The Company measures and reports its cash equivalents, restricted cash, and investments at fair value. Money market funds are measured at fair value on a recurring basis using quoted prices and are classified as Level 1. Investments are measured at fair value based on inputs other than quoted prices that are derived from observable market data and are classified as Level 2 inputs. Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of September 30, 2020 and December 31, 2019 are presented in the following tables (in thousands): Fair Value Measurements at September 30, 2020 Total Level 1 Level 2 Level 3 Money market funds $ 61,172 $ 61,172 $ — $ — Certificates of deposit 39,296 — 39,296 — Municipal notes 3,061 — 3,061 — Corporate notes 81,112 — 81,112 — Government and agency notes 11,192 — 11,192 — Total $ 195,833 $ 61,172 $ 134,661 $ — Fair Value Measurements at December 31, 2019 Total Level 1 Level 2 Level 3 Money market funds $ 30,054 $ 30,054 $ — $ — Certificates of deposit 20,046 — 20,046 — Repurchase agreements 15,000 — 15,000 — Corporate notes 38,783 — 38,783 — Government notes 7,574 — 7,574 — Commercial paper 1,096 — 1,096 — Total $ 112,553 $ 30,054 $ 82,499 $ — The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements at September 30, 2020 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds $ 61,172 $ — $ — $ 61,172 Certificates of deposit 39,046 250 — 39,296 Municipal notes 3,060 1 — 3,061 Corporate notes 80,871 274 (33 ) 81,112 Government and agency notes 11,171 22 (1 ) 11,192 Total cash equivalents and investments $ 195,320 $ 547 $ (34 ) $ 195,833 Classified as: Cash equivalents (maturities within 90 days) $ 62,152 Short-term investments (maturities within one year) 73,548 Long-term investments (maturities beyond 1 year) 60,133 Total cash equivalents and investments $ 195,833 Fair Value Measurements at December 31, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds $ 30,054 $ — $ — $ 30,054 Certificates of deposit 19,992 54 — 20,046 Repurchase agreements 15,000 — — 15,000 Corporate notes 38,788 — (5 ) 38,783 Government notes 7,563 11 7,574 Commercial paper 1,096 — — 1,096 Total cash equivalents and investments $ 112,493 $ 65 $ (5 ) $ 112,553 Classified as: Cash equivalents (maturities within 90 days) $ 47,140 Short-term investments (maturities within one year) 48,650 Long-term investments (maturities beyond 1 year) 16,763 Total cash equivalents and investments $ 112,553 As of September 30, 2020, the weighted average remaining contractual maturities of available-for-sale securities was approximately 11 months. There have been no significant realized losses on available-for-sale securities for the period presented. Based on the Company’s review of its available-for-sale securities, the Company has a limited number of available-for-sale securities in insignificant loss positions as of September 30, 2020, none of which have been in a loss position for more than one year. T The investments are classified as available-for-sale securities. At September 30, 2020 and December 31, 2019, the balance in the Company’s accumulated other comprehensive income was comprised solely of activity related to the Company’s available-for-sale securities. There were no realized gains or losses recognized on the sale or maturity of available-for-sale securities for the three or nine months ended September 30, 2020 and as a result, the Company did not reclassify any amounts out of accumulated other comprehensive income for the quarter. There were no transfers between Levels 1, 2 or 3 for the period presented.

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Cash, Cash Equivalents and Investments	Note 4: Cash, Cash Equivalents and Investments The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that sum to the total of the same amounts shown in the condensed statements of cash flows (in thousands): Nine Months Ended September 30, 2020 2019 Cash and cash equivalents $ 64,246 $ 44,740 Restricted cash — 250 Total cash, cash equivalents and restricted cash $ 64,246 $ 44,990 Restricted cash as of September 30, 2019 relates to a compensating balance to secure a credit card facility. There was no restricted cash as of September 30, 2020. The following tables categorize the fair values of cash, cash equivalents, and short-term investments measured at fair value on a recurring basis on our balance sheet (in thousands): September 30, 2020 December 31, 2019 Cash and cash equivalents: Cash $ 2,094 $ 4,074 Money market funds 61,172 30,054 Repurchase agreements — 15,000 Certificates of deposit 980 985 Corporate notes — 1,101 Total cash and cash equivalents $ 64,246 $ 51,214 Short-term investments: Commercial paper $ — $ 1,096 Certificates of deposit 31,168 15,428 Municipal notes 1,838 — Corporate notes 32,432 24,552 Government and agency notes 8,110 7,574 Total short-term investments $ 73,548 $ 48,650 Long-term investments Corporate notes $ 48,680 $ 13,130 Certificates of deposit 7,148 3,633 Municipal notes 1,223 — Government and agency notes 3,082 — Total long-term investments $ 60,133 $ 16,763

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2020
Balance Sheet Components [Abstract]
Balance Sheet Components	Note 5. Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, 2020 2019 Prepaid expenses $ 120 $ 129 Prepaid insurance 1,653 858 Prepaid research and development expenses 2,778 4,517 Other current assets 629 688 Total prepaid expenses and other current assets $ 5,180 $ 6,192 Property and Equipment Property and equipment, net consist of the following (in thousands): September 30 December 31 2020 2019 Computer equipment $ 33 $ 28 Lab equipment 405 405 Finance lease right of use assets 556 559 Leasehold improvement 21 — Office furniture 15 — Less: accumulated amortization and depreciation (530 ) (283 ) Property and equipment, net $ 500 $ 709 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, 2020 2019 Personnel expenses $ 1,846 $ 1,261 Professional fees 224 96 Research and development expenses 9,751 4,410 Other 279 50 Total accrued expenses and other current liabilities $ 12,100 $ 5,817

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	Note 6. Leases Real Estate Operating Leases In June 2018, the Company entered into a three-year lease agreement with no renewal options with a related party, one of the investors in the Series B redeemable convertible preferred stock. The lease began on July 16, 2018 and provides 3,185 square feet of office and laboratory space in South San Francisco, California. The Company issued 114,437 shares of its Series B redeemable convertible preferred stock with a fair value of $1.1 million in exchange for the leased facility. No other payments are due under the lease. The common area maintenance and other operating costs are included in the base rent th The Company completed its IPO on May 13, 2019 and as a result, pursuant to the terms of the lease agreement, all previously unvested shares were fully vested and as part of the IPO process, all outstanding shares of the Company’s redeemable convertible preferred stock including the Series B redeemable convertible preferred stock issued in connection with the lease agreement were converted into shares of the Company’s common stock on a 1-for-1 basis and the operating lease liability was extinguished. In May 2019 the Company entered into an amendment to the lease agreement to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company paid a one-time fee of approximately $63,000 for the additional space and the lease agreement will terminate in July 2021. No other payments are due under the lease agreement and no renewal option is available. As the entire lease is prepaid, there is no associated lease liability. In May 2020 the Company entered into a second amendment to the lease agreement to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company will pay rent monthly for the additional space and the lease agreement will terminate in July 2021. The Company recorded an operating lease asset and liability of $172,000. In May 2020 the Company entered into a lease agreement to rent space in San Diego, California for our clinical operations team. The lease agreement is for three years which commenced August 1, 2020. Total payments under the lease will be $337,000. The Company paid a security deposit of $29,000 and is included in Other Assets on our September 30, 2020 balance sheets. At the commencement of the lease, the Company recorded an operating lease asset of $326,000, which consists of an operating lease liability of $317,000 and cash rent prepayment of $9,000. The Company recognizes lease expense on a straight-line basis over the term of its operating lease. As of September 30, 2020, future rent expense of $760,000 will be recognized over the remaining terms of 10 to 34 months on a straight-line basis over the respective lease period. Clinical Equipment Operating Lease The Company uses certain vendor supplied equipment in connection with its on-going clinical trial. The Company has analyzed the vendor agreement and determined that it contains an embedded operating lease. The Company recognizes monthly the leases costs in our research and development expenses. The right of use asset and lease liability are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company’s lease does not provide an implicit rate. The Company used an adjusted historical incremental borrowing rate, based on the information available at the approximate lease commencement date, to determine the present value of lease payments. The remaining lease expense of $91,000 will be recognized over the remaining lease term of approximately 23 months. Clinical Equipment Financing Lease The Company uses certain vendor supplied equipment in connection with its on-going clinical trial. The Company has analyzed the vendor agreements and determined that they contain embedded finance leases. The Company recognizes the depreciation expense in research and development expenses in the statement of operations and recognizes expense on a straight-line basis starting when the equipment is placed into service until the end of the contract term ranging from 20 to 34 months. Amortization expense of the financing lease right of use asset for the nine months ended September 30, 2020 and 2019 was $173,000 and $53,000, respectively. Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): September 30, 2020 December 31, 2019 Operating lease right of use asset, net $ 848 $ 625 Short-term operating lease liability 279 — Long-term operating lease liability 244 — $ 523 $ — Finance lease right of use asset 556 559 Finance lease accumulated amortization (280 ) (107 ) Total finance lease right of use asset, net $ 276 $ 452 Weighted average remaining lease term Operating leases 1.3 years 1.6 years Finance leases 1.2 years 2.1 years Weighted average discount rate Operating leases 2.10 % — % Finance leases — % — % Year ended December 31, Operating Lease 2020 (excluding the nine months ended September 30, 2020) 80 2021 245 2022 141 2023 70 Total lease payments 536 Less: imputed interest (13 ) Total remaining lease liability 523

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	Note 7. Stock-Based Compensation On December 4, 2014, the Company’s stockholders approved the 2014 Stock Plan (“2014 Plan”) and amended the 2014 Plan on April 25, 2019. The 2014 Plan was amended, restated and re-named the 2019 Equity Incentive Plan (the “2019 Plan”), which became effective as of May 7, 2019, the day prior to the effectiveness of the registration statement filed in connection with the IPO. The remaining shares available for issuance under the 2014 Plan were added to the shares reserved for issuance under the 2019 Plan. The 2019 Plan provides for the grant of stock options (including incentive stock options and non-qualified stock options), stock appreciation rights, restricted stock, RSUs, performance units, and performance shares to the Company’s employees, directors, and consultants. The maximum aggregate number of shares that may be issued under the 2019 Plan is 5,131,549 shares of the Company’s common stock. In addition, the number of shares available for issuance under the 2019 Plan will be increased annually on the first day of each of its fiscal years beginning with fiscal 2020, by an amount equal to the least of (i) 2,146,354 shares of common stock; (ii) 4% of the outstanding shares of its common stock as of the last day of its immediately preceding fiscal year; and (iii) such other amount as the Company s Board of Directors may determine. The 2019 Plan may be amended, suspended or terminated by the Company’s Board of Directors at any time, provided such action does not impair the existing rights of any participant, subject to stockholder approval of any amendment to the 2019 Plan as required by applicable law or listing requirements. Unless sooner terminated by the Company’s Board of Directors, the 2019 Plan will automatically terminate on April 23, 2029. As of September 30, 2020, the Company had 2,014,728 shares available for future issuance under the 2019 Plan. For the three and nine months ended September 30, 2020, the Company recognized $4,158,000 and $9,511,000 of stock-based compensation expense, respectively, related to options granted to employees and non-employees. The compensation expense is allocated on a departmental basis, based on the classification of the option holder. No income tax benefits have been recognized in the statements of operations for stock-based compensation arrangements. Number of Options and Unvested Shares Weighted Average Exercise Price Weighted average remaining contractual life (years) Aggregate intrinsic value Balance at December 31, 2019 2,393,934 $ 5.35 8.62 $ 121,592,682 Options granted 1,710,145 51.16 Options exercised (124,836 ) 9.89 Options cancelled (210,318 ) 42.38 Balance at September 30, 2020 3,768,925 23.92 8.55 102,942,251 Options vested and expected to vest as of September 30, 2020 3,768,925 23.92 8.55 102,942,251 Options exercisable as of September 30, 2020 1,323,339 $ 8.57 7.73 $ 55,396,069 Future stock-based compensation for unvested employee and non-employee options granted and outstanding as of September 30, 2020 is The following table summarizes employee and non-employee stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 and the allocation within the statements of operations and comprehensive loss (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 General and administrative expense $ 2,261 $ 313 $ 4,915 $ 679 Research and development expense 1,897 599 4,596 800 Total stock-based compensation $ 4,158 $ 912 $ 9,511 $ 1,479 Employee Stock Purchase Plan On April 24, 2019, the Company’s Board of Directors adopted its 2019 Employee Stock Purchase Plan (“2019 ESPP”), which was subsequently approved by the Company’s stockholders and became effective on May 7, 2019, the day immediately prior to the effectiveness of the registration statement filed in connection with the IPO. The 2019 ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code (the “Code”) for U.S. employees. In addition, the 2019 ESPP authorizes grants of purchase rights that do not comply with Section 423 of the Code under a separate non-423 component for non-U.S. employees and certain non-U.S. service providers. The Company has reserved 536,989

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Note 8. Related Party Transactions In June 2014, the Company entered into a research grant and license agreement (the Agreement) with a stockholder of the Company. The Agreement requires the Company to pay royalties to the stockholder in the amount of 3% of gross revenues not to exceed $1.05 million. This agreement was amended in April 2019 and the royalty payment provision was removed. As described in Note 6, the Company entered into a three-year lease agreement with a Series B redeemable preferred stock investor. The lease began on July 16, 2018 and provides 3,185 square feet of office space in South San Francisco, California. The Company issued 114,437 restricted shares of its Series B redeemable convertible preferred stock in exchange for the use of the leased facility. In May 2019, the Company entered into an amendment to the lease agreement to rent additional space in the same building for a one-time payment of approximately $63,000 on the same terms as the July 2018 agreement except rent. As described in Note 1, the Company completed its IPO in May 2019. As a result of the IPO, in addition to the 229,453 shares of Series B redeemable convertible preferred stock held by the investor, an additional 82,649 shares of the Company’s Series B redeemable convertible preferred stock under issued pursuant the lease agreement fully vested and were converted into common stock of the Company on a one-to-one basis. As described in Note 1, o n February 10, 2020, the Company issued and sold shares of common stock at a purchase price of $50.00 per share in a private placement. In the private placement, the Company issued and sold 30,000 shares of common stock for an aggregate purchase price of $1,500,000 to an entity affiliated with David A. Lamond, a member of the Company’s Board of Directors. As described in Note 6, the Company entered into a second amendment to the lease agreement to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company will pay rent monthly for the additional space and the lease agreement will terminate in July 2021. The Company recorded an operating lease asset and liability of $172,000.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 9. Income Taxes The Company has a history of losses and expects to record a loss in 2020. The Company accounts for income taxes under ASC Topic 740 – Income Taxes. Under this standard, deferred tax assets and liabilities are recognized for future tax benefits or consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided for significant deferred tax assets when it is more likely than not that such assets will not be realized through future operations. No provision for income taxes has been recorded due to the available net operating loss carry forwards. Future tax benefits which may arise as a result of these losses have not been recognized in these financial statements, as their realization is determined not likely to occur and accordingly, the Company has recorded a valuation allowance for the future deferred tax assets. On March 27, 2020, President Trump signed the Coronavirus Aid, Relief, and Economic Security Act ("CARES Act") into law. The Company has reviewed the aspects of this law as it relates to income taxes and have concluded that at this time, the CARES Act will have no material impact to the Company’s 2020 provision for income taxes.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	Note 10. Net Loss Per Share The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the period presented due to their anti-dilutive effect: September 30, 2020 2019 Options issued and outstanding 3,768,925 2,422,195 Total 3,768,925 2,422,195

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and pursuant to the instructions of the SEC on The condensed balance sheet as of September 30, 2020, the condensed statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, the condensed statements of redeemable convertible preferred stock and stockholders’ equity for the three and nine months ended September 30, 2020 and 2019, the condensed statements of cash flows for the nine months ended September 30, 2020 and 2019, and the financial data and other financial information disclosed in the notes to the condensed financial statements are unaudited. These financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2019 included in the Company’s Form 10-K filed with the SEC on March 16, 2020.
Risks and Uncertainties	Risks and Uncertainties The pandemic caused by an outbreak of a new strain of coronavirus, COVID-19, has resulted, and is likely to continue to result, in significant national and global economic disruption and may adversely affect our business. The Company is actively monitoring the impact of COVID-19 and the possible effects on its financial condition, liquidity, operations, clinical trials, suppliers, industry and workforce. However, the full extent, consequences, and duration of the COVID-19 pandemic and the resulting impact on the Company cannot currently be predicted. The Company will continue to evaluate the impact that these events could have on the Company’s operations, financial position, and the results of operations and cash flows during fiscal year 2020 and beyond.
Use of Estimates	Use of Estimates The preparation of the Company’s financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and expenses, as well as related disclosure of contingent assets and liabilities. The most significant estimates used in the Company’s financial statements relate to the determination of the fair value of common stock prior to the initial public offering, stock-based awards and other issuances, accruals for research and development costs, useful lives of long-lived assets, stock-based compensation and related assumptions, the incremental borrowing rate for leases and income tax uncertainties, including a valuation allowance for deferred tax assets; and contingencies. The Company bases its estimates on historical experience and on various other market specific and other relevant assumptions that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from the Company’s estimates.
Significant Accounting Policies	Significant Accounting Policies There have been no significant changes to the accounting policies during the nine months ended September 30, 2020, as compared to the significant accounting policies described in our Annual Report on Form 10-K.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value. There are no unrealized gains or losses on the money market funds for the periods presented.
Fair Value Measurements	Fair Value Measurements The fair value of our financial instruments reflects the amounts that we estimate we would receive in connection with the sale of an asset or pay in connection with the transfer of a liability in an orderly transaction between market participants at the measurement date (exit price). We disclose and recognize the fair value of our Level 1 - Inputs that reflect unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access at the measurement date; Level 2 - Inputs other than quoted prices that are observable for the assets or liability either directly or indirectly, including inputs in markets that are not considered to be active; Level 3 - Inputs that are unobservable. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period.
Leases	Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update, or ASU, No. 2016-02, Leases (Topic 842), to enhance the transparency and comparability of financial reporting related to leasing arrangements. The Company adopted the standard effective January 1, 2019. The Company determines if an arrangement includes a lease at inception. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset includes any lease payments made and excludes lease incentives. Incremental borrowing rate is used in determining the present value of future payments. The Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. The lease terms may include options to extend or terminate the lease. Lease expense for minimum lease payments is recognized on a straight-line basis over the non-cancelable lease term. The Company has elected not to recognize a right-of-use asset and lease liability for short-term leases. A short-term lease is a lease with an expected lease term of 12 months or less and which does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. The Company also elected the package of practical expedients under the transition guidance that will retain the historical lease classification and initial direct costs for any leases that exist prior to adoption of the new guidance and the practical expedient to not separate lease and non-lease components. See Note 6 for further disclosure. Finance lease right of use assets are recorded on the balance sheet in Property and equipment, net. The current portion of the operating lease liability is recorded in accrued expenses and other current liabilities.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to not use this extended transition period for complying with certain new or revised accounting standards that have different effective dates for public and private companies.
Recently Accounting Pronouncements Adopted and Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. The new guidance changes disclosure requirements related to fair value measurements as part of the disclosure framework project. The disclosure framework project aims to improve the effectiveness of disclosures in the notes to the financial statements by focusing on requirements that clearly communicate the most important information to users of the financial statements. The Company adopted this effective January 1, 2020. The adoption of this pronouncement did not have a material impact on its financial statements or disclosures. In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40)”: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”), which clarifies the accounting for implementation costs in cloud computing arrangements. The Company adopted the standard prospectively on January 1, 2020. The adoption of this pronouncement did not have a material impact on its financial statements. Recent Accounting Pronouncements Not Yet Adopted The following are new accounting pronouncements that the Company is evaluating for future impacts on its financial statements: Financial Instruments—Credit Losses: In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments which amends the principles around the recognition of credit losses by mandating entities incorporate an estimate of current expected credit losses when determining the value of certain assets. The guidance also amends reporting around allowances for credit losses on available-for-sale marketable securities. For Smaller Reporting Companies as defined by the SEC, ASU 2016-13 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. The Company is evaluating the impact of the guidance on its financial statements. All other newly issued accounting pronouncements not yet effective have been deemed either immaterial or not applicable.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities to Fair Value Measurements on Recurring Basis	Financial assets and liabilities subject to fair value measurements on a recurring basis and the level of inputs used in such measurements by major security type as of September 30, 2020 and December 31, 2019 are presented in the following tables (in thousands): Fair Value Measurements at September 30, 2020 Total Level 1 Level 2 Level 3 Money market funds $ 61,172 $ 61,172 $ — $ — Certificates of deposit 39,296 — 39,296 — Municipal notes 3,061 — 3,061 — Corporate notes 81,112 — 81,112 — Government and agency notes 11,192 — 11,192 — Total $ 195,833 $ 61,172 $ 134,661 $ — Fair Value Measurements at December 31, 2019 Total Level 1 Level 2 Level 3 Money market funds $ 30,054 $ 30,054 $ — $ — Certificates of deposit 20,046 — 20,046 — Repurchase agreements 15,000 — 15,000 — Corporate notes 38,783 — 38,783 — Government notes 7,574 — 7,574 — Commercial paper 1,096 — 1,096 — Total $ 112,553 $ 30,054 $ 82,499 $ —
Summary of Available-for-Sale Securities	The following table summarizes the available-for-sale securities (in thousands): Fair Value Measurements at September 30, 2020 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds $ 61,172 $ — $ — $ 61,172 Certificates of deposit 39,046 250 — 39,296 Municipal notes 3,060 1 — 3,061 Corporate notes 80,871 274 (33 ) 81,112 Government and agency notes 11,171 22 (1 ) 11,192 Total cash equivalents and investments $ 195,320 $ 547 $ (34 ) $ 195,833 Classified as: Cash equivalents (maturities within 90 days) $ 62,152 Short-term investments (maturities within one year) 73,548 Long-term investments (maturities beyond 1 year) 60,133 Total cash equivalents and investments $ 195,833 Fair Value Measurements at December 31, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds $ 30,054 $ — $ — $ 30,054 Certificates of deposit 19,992 54 — 20,046 Repurchase agreements 15,000 — — 15,000 Corporate notes 38,788 — (5 ) 38,783 Government notes 7,563 11 7,574 Commercial paper 1,096 — — 1,096 Total cash equivalents and investments $ 112,493 $ 65 $ (5 ) $ 112,553 Classified as: Cash equivalents (maturities within 90 days) $ 47,140 Short-term investments (maturities within one year) 48,650 Long-term investments (maturities beyond 1 year) 16,763 Total cash equivalents and investments $ 112,553

Cash, Cash Equivalents and In_2

Cash, Cash Equivalents and Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Summary of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that sum to the total of the same amounts shown in the condensed statements of cash flows (in thousands): Nine Months Ended September 30, 2020 2019 Cash and cash equivalents $ 64,246 $ 44,740 Restricted cash — 250 Total cash, cash equivalents and restricted cash $ 64,246 $ 44,990
Summary of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis	The following tables categorize the fair values of cash, cash equivalents, and short-term investments measured at fair value on a recurring basis on our balance sheet (in thousands): September 30, 2020 December 31, 2019 Cash and cash equivalents: Cash $ 2,094 $ 4,074 Money market funds 61,172 30,054 Repurchase agreements — 15,000 Certificates of deposit 980 985 Corporate notes — 1,101 Total cash and cash equivalents $ 64,246 $ 51,214 Short-term investments: Commercial paper $ — $ 1,096 Certificates of deposit 31,168 15,428 Municipal notes 1,838 — Corporate notes 32,432 24,552 Government and agency notes 8,110 7,574 Total short-term investments $ 73,548 $ 48,650 Long-term investments Corporate notes $ 48,680 $ 13,130 Certificates of deposit 7,148 3,633 Municipal notes 1,223 — Government and agency notes 3,082 — Total long-term investments $ 60,133 $ 16,763

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2020
Balance Sheet Components [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, 2020 2019 Prepaid expenses $ 120 $ 129 Prepaid insurance 1,653 858 Prepaid research and development expenses 2,778 4,517 Other current assets 629 688 Total prepaid expenses and other current assets $ 5,180 $ 6,192
Schedule of Property and Equipment, Net	Property and equipment, net consist of the following (in thousands): September 30 December 31 2020 2019 Computer equipment $ 33 $ 28 Lab equipment 405 405 Finance lease right of use assets 556 559 Leasehold improvement 21 — Office furniture 15 — Less: accumulated amortization and depreciation (530 ) (283 ) Property and equipment, net $ 500 $ 709
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): September 30, December 31, 2020 2019 Personnel expenses $ 1,846 $ 1,261 Professional fees 224 96 Research and development expenses 9,751 4,410 Other 279 50 Total accrued expenses and other current liabilities $ 12,100 $ 5,817

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates): September 30, 2020 December 31, 2019 Operating lease right of use asset, net $ 848 $ 625 Short-term operating lease liability 279 — Long-term operating lease liability 244 — $ 523 $ — Finance lease right of use asset 556 559 Finance lease accumulated amortization (280 ) (107 ) Total finance lease right of use asset, net $ 276 $ 452 Weighted average remaining lease term Operating leases 1.3 years 1.6 years Finance leases 1.2 years 2.1 years Weighted average discount rate Operating leases 2.10 % — % Finance leases — % — % Year ended December 31, Operating Lease 2020 (excluding the nine months ended September 30, 2020) 80 2021 245 2022 141 2023 70 Total lease payments 536 Less: imputed interest (13 ) Total remaining lease liability 523

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Options Activity	Number of Options and Unvested Shares Weighted Average Exercise Price Weighted average remaining contractual life (years) Aggregate intrinsic value Balance at December 31, 2019 2,393,934 $ 5.35 8.62 $ 121,592,682 Options granted 1,710,145 51.16 Options exercised (124,836 ) 9.89 Options cancelled (210,318 ) 42.38 Balance at September 30, 2020 3,768,925 23.92 8.55 102,942,251 Options vested and expected to vest as of September 30, 2020 3,768,925 23.92 8.55 102,942,251 Options exercisable as of September 30, 2020 1,323,339 $ 8.57 7.73 $ 55,396,069
Summary of Employee and Non-Employee Stock-Based Compensation Expense	The following table summarizes employee and non-employee stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 and the allocation within the statements of operations and comprehensive loss (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 General and administrative expense $ 2,261 $ 313 $ 4,915 $ 679 Research and development expense 1,897 599 4,596 800 Total stock-based compensation $ 4,158 $ 912 $ 9,511 $ 1,479

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Outstanding Potentially Dilutive Ordinary Shares Excluded from Calculation of Diluted Net Loss Per Share	The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the period presented due to their anti-dilutive effect: September 30, 2020 2019 Options issued and outstanding 3,768,925 2,422,195 Total 3,768,925 2,422,195

Organization - Additional Infor

Organization - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	May 13, 2019	Feb. 29, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Entity incorporation date			2012-06
Proceeds from issuance of common stock, net of underwriting discounts and commissions and offering expenses				$ 77,827
Accumulated deficit			$ (126,099)		$ (69,805)
Cash, cash equivalents, and short-term investments			137,800
Long term investments			$ 60,133		$ 16,763
IPO
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Issuance of stock (in shares)	5,073,800
Offering price per share	$ 17
Proceeds from issuance of common stock, net of underwriting discounts and commissions and offering expenses	$ 77,800
Conversion of redeemable convertible preferred stock to common stock	18,161,027
Convertible redeemable preferred stock, shares outstanding	0
Underwriters
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Issuance of stock (in shares)	661,800
Private Placement
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Issuance of stock (in shares)		2,500,000
Offering price per share		$ 50
Agreement date		Feb. 10, 2020
Proceeds from issuance of common stock		$ 125,000
Costs related to offering		$ 7,400

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020USD ($)
Accounting Standards Update 2018-13 [Member]
Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 1, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
Accounting Standards Update 2018-15 [Member]
Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 1, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
Money Market Funds
Summary Of Significant Accounting Policies [Line Items]
Unrealized gains or loss	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	$ 195,833	$ 112,553
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	61,172	30,054
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	39,296	20,046
Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	3,061
Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		15,000
Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	81,112	38,783
Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	11,192	7,574
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		1,096
Level 1
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	61,172	30,054
Level 1 | Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	61,172	30,054
Level 2
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	134,661	82,499
Level 2 | Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	39,296	20,046
Level 2 | Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	3,061
Level 2 | Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		15,000
Level 2 | Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	81,112	38,783
Level 2 | Government and Agency Notes
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities	$ 11,192	7,574
Level 2 | Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Financial assets and liabilities		$ 1,096

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 195,320	$ 112,493
Unrealized Gains	547	65
Unrealized Losses	(34)	(5)
Financial assets and liabilities	195,833	112,553
Cash equivalents (maturities within 90 days)	62,152	47,140
Short-term investments (maturities within one year)	73,548	48,650
Long-term investments (maturities beyond 1 year)	60,133	16,763
Total cash equivalents and investments	195,833	112,553
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	61,172	30,054
Financial assets and liabilities	61,172	30,054
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	39,046	19,992
Unrealized Gains	250	54
Financial assets and liabilities	39,296	20,046
Municipal Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	3,060
Unrealized Gains	1
Financial assets and liabilities	3,061
Repurchase Agreements
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		15,000
Financial assets and liabilities		15,000
Corporate Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	80,871	38,788
Unrealized Gains	274
Unrealized Losses	(33)	(5)
Financial assets and liabilities	81,112	38,783
Government Notes
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	11,171	7,563
Unrealized Gains	22	11
Unrealized Losses	(1)
Financial assets and liabilities	$ 11,192	7,574
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		1,096
Financial assets and liabilities		$ 1,096

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Available-for-sale securities loss position for more than 120 days	$ 0	$ 0
Other-than-temporary impairments on available-for-sale securities		0
Realized gains or losses recognized on the sale or maturity of available-for-sale securities	0	0
Fair value assets level 1 to level 2	0	0	$ 0
Fair value assets level 2 to level 1	$ 0	0	0
Fair value assets transfers into level 3		0	0
Fair value assets transfers out of level 3		$ 0	$ 0

Cash, Cash Equivalents and In_3

Cash, Cash Equivalents and Investments - Summary of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Cash and cash equivalents	$ 64,246,000	$ 51,214,000	$ 44,740,000
Restricted cash	0		250,000
Total cash, cash equivalents and restricted cash	$ 64,246,000	$ 51,214,000	$ 44,990,000	$ 24,872,000

Cash, Cash Equivalents and In_4

Cash, Cash Equivalents and Investments - Additional Information (Details) - USD ($)	Sep. 30, 2020	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Restricted cash	$ 0	$ 250,000

Cash, Cash Equivalents and In_5

Cash, Cash Equivalents and Investments - Summary of Fair Values of Cash, Cash Equivalents, and Short-Term Investments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	$ 62,152	$ 47,140
Short term investments	73,548	48,650
Long term investments	60,133	16,763
Fair Value on Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	64,246	51,214
Short term investments	73,548	48,650
Long term investments	60,133	16,763
Fair Value on Recurring | Cash
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	2,094	4,074
Fair Value on Recurring | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	61,172	30,054
Fair Value on Recurring | Repurchase Agreements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents		15,000
Fair Value on Recurring | Certificates of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents	980	985
Short term investments	31,168	15,428
Long term investments	7,148	3,633
Fair Value on Recurring | Corporate Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash and cash equivalents		1,101
Short term investments	32,432	24,552
Long term investments	48,680	13,130
Fair Value on Recurring | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments		1,096
Fair Value on Recurring | Municipal Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	1,838
Long term investments	1,223
Fair Value on Recurring | Government Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short term investments	8,110	$ 7,574
Long term investments	$ 3,082

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses	$ 120	$ 129
Prepaid insurance	1,653	858
Prepaid research and development expenses	2,778	4,517
Other current assets	629	688
Total prepaid expenses and other current assets	$ 5,180	$ 6,192

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Less: accumulated amortization and depreciation	$ (530)	$ (283)
Property and equipment, net	500	709
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment	33	28
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment	405	405
Finance Lease Right of Use Assets
Property Plant And Equipment [Line Items]
Property and equipment	556	$ 559
Leasehold Improvement
Property Plant And Equipment [Line Items]
Property and equipment	21
Office Furniture
Property Plant And Equipment [Line Items]
Property and equipment	$ 15

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accrued Liabilities Current [Abstract]
Personnel expenses	$ 1,846	$ 1,261
Professional fees	224	96
Research and development expenses	9,751	4,410
Other	279	50
Total accrued expenses and other current liabilities	$ 12,100	$ 5,817

Leases - Additional Information

Leases - Additional Information (Details)	1 Months Ended			9 Months Ended
	May 31, 2020USD ($)	May 31, 2019USD ($)	Jun. 30, 2018USD ($)ft²Investorshares	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)	May 13, 2019	Jul. 16, 2018
Lessee Lease Description [Line Items]
Lease agreement period								3 years
Renewal options		false
Number of investors | Investor			1
Operating lease payments		$ 0	$ 0
Repurchase option percentage			100.00%
Operating leases period			3 years
Operating lease payments paid for additional space		$ 63,000
Operating lease termination month and year	2021-07	2021-07
Operating lease liability	$ 172,000	$ 0		$ 523,000
Operating lease asset	$ 172,000			848,000		$ 625,000
Long-term operating lease liability				244,000
Future rent expense				760,000
Amortization expense of finance lease right-of-use asset				173,000	$ 53,000
Clinical Equipment
Lessee Lease Description [Line Items]
Remaining lease expense				$ 91,000
Remaining lease term				23 months
Minimum
Lessee Lease Description [Line Items]
Operating lease remaining term on a straight-line basis				10 months
Finance lease amortized period on equipment service				20 months
Maximum
Lessee Lease Description [Line Items]
Operating lease remaining term on a straight-line basis				34 months
Finance lease amortized period on equipment service				34 months
San Diego, California
Lessee Lease Description [Line Items]
Lease agreement period	3 years
Operating lease payments	$ 337,000
Operating lease asset	326,000
Long-term operating lease liability	317,000
Rent prepayment	9,000
San Diego, California | Other Assets
Lessee Lease Description [Line Items]
Security deposit paid	$ 29,000
Series B Redeemable Convertible Preferred Stock
Lessee Lease Description [Line Items]
Lease agreement period			3 years
Renewal options			false
Area under lease | ft²			3,185
Shares issued | shares			114,437
Convertible preferred stock, fair value			$ 1,100,000
Series B Redeemable Convertible Preferred Stock | IPO
Lessee Lease Description [Line Items]
Conversion of redeemable convertible preferred stock to common stock ratio		100.00%					100.00%

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($)	Sep. 30, 2020	May 31, 2020	Dec. 31, 2019	May 31, 2019
Leases [Abstract]
Operating lease right-of-use assets, net	$ 848,000	$ 172,000	$ 625,000
Short-term operating lease liability	279,000
Long-term operating lease liability	244,000
Operating lease liability	523,000	172,000		$ 0
Finance lease right of use asset	556,000		559,000
Finance lease accumulated amortization	(280,000)		(107,000)
Total finance lease right of use asset, net	$ 276,000		$ 452,000
Weighted average remaining lease term
Operating leases	1 year 3 months 18 days		1 year 7 months 6 days
Finance leases	1 year 2 months 12 days		2 years 1 month 6 days
Weighted average discount rate
Operating leases	2.10%
Operating Lease, Liability, Payment, Due [Abstract]
2020 (excluding the nine months ended September 30, 2020)	$ 80,000
2021	245,000
2022	141,000
2023	70,000
Total lease payments	536,000
Less: imputed interest	(13,000)
Operating lease liability	$ 523,000	$ 172,000		$ 0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	May 07, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted	$ 4,158,000	$ 912,000	$ 9,511,000	$ 1,479,000
Income tax benefits recognized			0
Unrecognized share-based compensation cost	54,000,000		$ 54,000,000
Unrecognized share-based compensation cost expected to be recognized, period			1 year 8 months 12 days
Weighted average grant date fair value of options granted			$ 37.03
Employees and Non-Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense related to options granted	$ 4,158,000		$ 9,511,000
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum aggregate number of shares that may be issued under the plan					5,131,549
Increase in number of shares available for issuance as proportion of shares of common stock	2,146,354		2,146,354
Percentage of common stock outstanding			4.00%
Common stock reserved for issuance	2,014,728		2,014,728
2019 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares available for issuance as proportion of shares of common stock	536,589		536,589
Percentage of common stock outstanding			1.00%
Common stock reserved for issuance					536,989
Maximum period for common stock shares reserved for future issuance			10 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - 2019 Plan	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options and Unvested Shares, beginning balance | shares	2,393,934
Number of Options and Unvested Shares, granted | shares	1,710,145
Number of Options and Unvested Shares, exercised | shares	(124,836)
Number of Options and Unvested Shares, cancelled | shares	(210,318)
Number of Options and Unvested Shares, ending balance | shares	3,768,925	2,393,934
Number of Options and Unvested Shares, vested and expected to vest | shares	3,768,925
Number of Options and Unvested Shares, exercisable | shares	1,323,339
Weighted Average Exercise Price, beginning balance | $ / shares	$ 5.35
Weighted Average Exercise Price, granted | $ / shares	51.16
Weighted Average Exercise Price, exercised | $ / shares	9.89
Weighted Average Exercise Price, cancelled | $ / shares	42.38
Weighted Average Exercise Price, ending balance | $ / shares	23.92	$ 5.35
Weighted Average Exercise Price, vested and expected to vest | $ / shares	23.92
Weighted Average Exercise Price, exercisable | $ / shares	$ 8.57
Weighted average remaining contractual life	8 years 6 months 18 days	8 years 7 months 13 days
Weighted average remaining contractual life, vested and expected to vest	8 years 6 months 18 days
Weighted average remaining contractual life, exercisable	7 years 8 months 23 days
Aggregate intrinsic value | $	$ 102,942,251	$ 121,592,682
Aggregate intrinsic value, vested and expected to vest | $	102,942,251
Aggregate intrinsic value, exercisable | $	$ 55,396,069

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Employee and Non-Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 4,158	$ 912	$ 9,511	$ 1,479
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	2,261	313	4,915	679
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,897	$ 599	$ 4,596	$ 800

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	Feb. 10, 2020USD ($)$ / sharesshares	May 13, 2019$ / sharesshares	Jul. 16, 2018ft²shares	May 31, 2020USD ($)	Feb. 29, 2020USD ($)$ / sharesshares	May 31, 2019USD ($)shares	Jun. 30, 2014USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Jun. 30, 2018
Related Party Transaction [Line Items]
Percentage of royalties payment to stockholders in amount of gross revenues							3.00%
Lease agreement period			3 years
Restricted stock shares issued | shares			114,437
Operating lease payments paid for additional space | $						$ 63,000
Operating lease termination month and year				2021-07		2021-07
Operating lease asset | $				$ 172,000				$ 848,000	$ 625,000
Operating lease liability | $				$ 172,000		$ 0		$ 523,000
IPO
Related Party Transaction [Line Items]
Number of shares issued and sold | shares		5,073,800
Offering price per share | $ / shares		$ 17
Private Placement
Related Party Transaction [Line Items]
Agreement date					Feb. 10, 2020
Number of shares issued and sold | shares					2,500,000
Proceeds from issuance of common stock | $					$ 125,000,000
Offering price per share | $ / shares					$ 50
Private Placement | David A. Lamond
Related Party Transaction [Line Items]
Agreement date	Feb. 10, 2020
Number of shares issued and sold | shares	30,000
Proceeds from issuance of common stock | $	$ 1,500,000
Offering price per share | $ / shares	$ 50
South San Francisco, California
Related Party Transaction [Line Items]
Area of lease office space | ft²			3,185
Series B Redeemable Convertible Preferred Stock
Related Party Transaction [Line Items]
Lease agreement period										3 years
Series B Redeemable Convertible Preferred Stock | IPO
Related Party Transaction [Line Items]
Conversion of preferred stock into common stock | shares						82,649
Conversion of redeemable convertible preferred stock to common stock ratio		100.00%				100.00%
Series B Redeemable Convertible Preferred Stock | IPO | Series B Redeemable Convertible Preferred Stock Investor
Related Party Transaction [Line Items]
Conversion of preferred stock into common stock | shares						229,453
Maximum
Related Party Transaction [Line Items]
Payment of royalties to stockholders | $							$ 1,050,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020USD ($)
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 0

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Outstanding Potentially Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	3,768,925	2,422,195
Options Issued and Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of earnings per share, amount	3,768,925	2,422,195