Athira Pharma (ATHA) 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. 09, 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
Entity Registrant Name	Athira Pharma, Inc.
Entity Central Index Key	0001620463
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		32,485,184
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity File Number	001-39503
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3368487
Entity Address, Address Line One	4000 Mason Road
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98195
City Area Code	206
Local Phone Number	221-8112
Document Quarterly Report	true
Document Transition Report	false
Security12b Title	Common Stock, $0.0001 par value per share
Trading Symbol	ATHA
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 165,725	$ 2,056
Short-term investments	60,547
Prepaid expenses and other current assets	5,994	97
Current portion of unsecured related party note receivable		7
Total current assets	232,266	2,160
Property and equipment, net	1,003
Operating lease right-of-use asset	959
Long-term investments	33,656
Other long-term assets	55
Unsecured related party note receivable		29
Total assets	267,939	2,189
Current liabilities:
Accounts payable	3,872	421
Accrued liabilities	2,125	852
Current operating lease liability	57
Grant liability	1,500
Total current liabilities	7,554	1,273
Operating lease liability, less current portion	915
Grant liability		1,036
Derivative liability		999
Convertible notes, net		1,553
Total liabilities	8,469	4,861
Commitments and contingencies (Note 8)
Convertible preferred stock, $0.0001 par value; 0 and 2,797,464 shares authorized at September 30, 2020 and December 31, 2019, respectively; 0 and 2,617,386 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively		17,051
Stockholders' equity (deficit):
Common stock, $0.0001 par value; 900,000,000 and 10,088,017 shares authorized at September 30, 2020 and December 31, 2019, respectively; 31,087,395 and 3,641,449 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	3
Additional paid-in capital	292,800	1,364
Accumulated other comprehensive income	7
Accumulated deficit	(33,340)	(21,087)
Total stockholders' equity (deficit)	259,470	(19,723)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 267,939	$ 2,189

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	2,797,464
Convertible preferred stock, shares issued	0	2,617,386
Convertible preferred stock, shares outstanding	0	2,617,386
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	900,000,000	10,088,017
Common stock, shares issued	31,087,395	3,641,449
Common stock, shares outstanding	31,087,395	3,641,449

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - 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	$ 5,830	$ 1,026	$ 8,099	$ 3,135
General and administrative	1,567	509	2,817	1,197
Total operating expenses	7,397	1,535	10,916	4,332
Loss from operations	(7,397)	(1,535)	(10,916)	(4,332)
Other income (expense), net	(1,059)	5	(1,337)	145
Net loss	(8,456)	(1,530)	(12,253)	(4,187)
Unrealized (loss)/gain on available-for-sale securities	7		7
Comprehensive loss attributable to common shareholders	$ (8,449)	$ (1,530)	$ (12,246)	$ (4,187)
Net loss per share attributable to common stockholders, basic and diluted	$ (1.12)	$ (0.43)	$ (2.38)	$ (1.18)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	7,564,538	3,554,345	5,155,338	3,551,586

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities
Net loss	$ (12,253)	$ (4,187)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	218	189
Change in fair value of derivative liability	132	84
Change in fair value of convertible preferred stock warrant liability	641
Change in fair value of grant liability	464	51
Accretion of discounts on convertible notes	289	175
Non-cash interest expense	76	61
Gain on extinguishment of convertible notes	(199)
Amortization of available-for-sale securities	86
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(5,919)	16
Accounts payable and accrued expenses	3,004	927
Operating lease liability	13
Net cash (used in) operating activities	(13,448)	(2,684)
Investing activities
Purchases of available-for-sale securities	(94,281)	(995)
Maturities of available-for-sale securities		1,745
Purchases of property and equipment	(65)
Principal payments received on stockholder note receivable	36	5
Net cash (used in) provided by investing activities	(94,310)	755
Financing activities
Proceeds from exercise of common stock options and common stock warrants	613	13
Proceeds from initial public offering, net of issuance costs	187,224
Proceeds from sales of convertible preferred stock and stock warrants, net of issuance costs	81,926
Proceeds from issuance of convertible notes, including derivative	1,666	884
Issuance costs of convertible notes	(2)	(5)
Proceeds from Paycheck Protection Program loan	215
Repayment of Paycheck Protection Program loan	(215)
Net cash provided by financing activities	271,427	892
Net increase (decrease) in cash and cash equivalents	163,669	(1,037)
Cash and cash equivalents, beginning of period	2,056	3,317
Cash and cash equivalents, end of period	165,725	2,280
Supplemental disclosures of cash flow information:
Purchases of property and equipment included in accounts payable and accrued liabilities	940
Deferred offering costs included in accounts payable and accrued liabilities	779
Issuance of common stock warrants in connection with Series B convertible preferred stock financing	10,591
Issuance of Series B preferred stock upon conversion of promissory notes	4,515
Recognition of warrant liability in connection with Series B convertible preferred stock financing	364
Derivative liability recorded upon issuance of convertible notes	774	$ 390
Conversion of convertible preferred stock upon closing of initial public offering	92,537
Right-of-use asset obtained in exchange for new operating lease liability	$ 975

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) Equity (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ (14,887)			$ 1,039		$ (15,926)
Temporary equity, beginning balance, shares at Dec. 31, 2018		2,617,386
Temporary equity, beginning balance at Dec. 31, 2018		$ 17,051
Beginning balance, shares at Dec. 31, 2018			3,559,484
Issuance of common stock upon exercise of common stock options	13			13
Issuance of common stock upon exercise of common stock options, shares			12,610
Stock-based compensation	189			189
Net loss	(4,187)					(4,187)
Ending balance at Sep. 30, 2019	(18,872)			1,241		(20,113)
Temporary equity, ending balance, shares at Sep. 30, 2019		2,617,386
Temporary equity, ending balance at Sep. 30, 2019		$ 17,051
Ending balance, shares at Sep. 30, 2019			3,572,094
Beginning balance at Jun. 30, 2019	(17,417)			1,166		(18,583)
Temporary equity, beginning balance, shares at Jun. 30, 2019		2,617,386
Temporary equity, beginning balance at Jun. 30, 2019		$ 17,051
Beginning balance, shares at Jun. 30, 2019			3,565,789
Issuance of common stock upon exercise of common stock options	6			6
Issuance of common stock upon exercise of common stock options, shares			6,305
Stock-based compensation	69			69
Net loss	(1,530)					(1,530)
Ending balance at Sep. 30, 2019	(18,872)			1,241		(20,113)
Temporary equity, ending balance, shares at Sep. 30, 2019		2,617,386
Temporary equity, ending balance at Sep. 30, 2019		$ 17,051
Ending balance, shares at Sep. 30, 2019			3,572,094
Beginning balance at Dec. 31, 2019	$ (19,723)			1,364		(21,087)
Temporary equity, beginning balance, shares at Dec. 31, 2019	2,617,386	2,617,386
Temporary equity, beginning balance at Dec. 31, 2019	$ 17,051	$ 17,051
Beginning balance, shares at Dec. 31, 2019			3,641,449
Issuance of common stock upon exercise of common stock options	$ 542			542
Issuance of common stock upon exercise of common stock options, shares	540,334		540,334
Issuance of Series B convertible preferred stock and common stock warrants, net of issuance costs of $3.5 million	$ 10,591			10,591
Temporary Equity, Issuance of Series B convertible preferred stock and common stock warrants, net, shares		9,372,765
Temporary Equity, Issuance of Series B convertible preferred stock and common stock warrants, net		$ 70,971
Temporary Equity, Issuance of the Series B-1 convertible preferred stock upon conversion of convertible notes, shares		512,858
Temporary Equity, Issuance of the Series B-1 convertible preferred stock upon conversion of convertible notes		$ 4,515
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs	186,446		$ 1	186,445
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs, Shares			12,000,000
Conversion of convertible preferred stock	92,537		$ 2	92,535
Temporary equity, conversion of convertible preferred stock, shares		(12,503,009)
Temporary equity, conversion of convertible preferred stock		$ (92,537)
Conversion of convertible preferred stock, shares			12,503,009
Exercise of common stock warrants	1,105			1,105
Exercise of common stock warrants, shares			2,402,603
Stock-based compensation	218			218
Other comprehensive income	7				$ 7
Net loss	(12,253)					(12,253)
Ending balance at Sep. 30, 2020	$ 259,470		$ 3	292,800	7	(33,340)
Temporary equity, ending balance, shares at Sep. 30, 2020	0
Ending balance, shares at Sep. 30, 2020			31,087,395
Beginning balance at Jun. 30, 2020	$ (12,529)			12,355		(24,884)
Temporary equity, beginning balance, shares at Jun. 30, 2020		12,503,009
Temporary equity, beginning balance at Jun. 30, 2020		$ 92,537
Beginning balance, shares at Jun. 30, 2020			4,607,565
Issuance of common stock upon exercise of common stock options	304			304
Issuance of common stock upon exercise of common stock options, shares			262,285
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs	186,446		$ 1	186,445
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs, Shares			12,000,000
Conversion of convertible preferred stock	92,537		$ 2	92,535
Temporary equity, conversion of convertible preferred stock, shares		(12,503,009)
Temporary equity, conversion of convertible preferred stock		$ (92,537)
Conversion of convertible preferred stock, shares			12,503,009
Exercise of common stock warrants	1,050			1,050
Exercise of common stock warrants, shares			1,714,536
Stock-based compensation	111			111
Other comprehensive income	7				7
Net loss	(8,456)					(8,456)
Ending balance at Sep. 30, 2020	$ 259,470		$ 3	$ 292,800	$ 7	$ (33,340)
Temporary equity, ending balance, shares at Sep. 30, 2020	0
Ending balance, shares at Sep. 30, 2020			31,087,395

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Statement Of Stockholders Equity [Abstract]
Issuance of Series B convertible preferred stock and common stock warrants, issuance costs		$ 3.5
Initial public offering, issuance cost	$ 3.3	$ 3.3

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. Description of Business Organization Athira Pharma, Inc. (the “Company”) was incorporated as M3 Biotechnology, Inc. in the state of Washington on March 31, 2011 and reincorporated in the state of Delaware on October 27, 2015. In April 2019, the Company changed its name to Athira Pharma, Inc. The Company currently has office and laboratory space in Seattle and Bothell Washington. The Company is a late clinical-stage biopharmaceutical company focused on developing small molecules to restore neuronal health and stop neurodegeneration. Reverse Stock Split On September 11, 2020, the Company effected a one-for-7.9302 reverse split of its issued and outstanding common stock, convertible preferred stock, warrants, and stock options. The par value of the common stock and convertible preferred stock was not adjusted as a result of the reverse stock split. All share and per share amounts in the accompanying unaudited condensed financial statements and notes to the unaudited condensed financial statements have been retroactively adjusted for all periods presented to reflect the reverse stock split. Initial Public Offering On September 17, 2020, the Company’s registration statement on Form S-1 (File No. 333-248428) for its initial public offering of common stock (“IPO”) was declared effective by the Securities and Exchange Commission (“SEC”). On September 22, 2020, t he Company In connection with the closing of the IPO, all of the Company’s outstanding shares of convertible preferred stock were automatically converted into 12,503,009 shares of common stock. Immediately prior to t he Company’s Liquidity and Capital Resources Since the Company’s inception, it has funded its operations primarily with proceeds from the sale and issuance of common stock, convertible preferred stock, common stock warrants, and convertible notes, and to a lesser extent from grant income and stock option exercises. From the Company’s inception through September 30, 2020, it has raised aggregate net cash proceeds of $288.5 million primarily from the issuance of its common stock, convertible preferred stock, common stock warrants, and convertible notes. As of September 30, 2020, the Company had $259.9 million in cash, cash equivalents, and investments and had not generated positive cash flows from operations. Since the Company’s inception, it has devoted substantially all of its resources to its research and development efforts such as small molecule compound discovery, nonclinical studies and clinical trials, as well as manufacturing activities, establishing and maintaining the Company’s intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. Based upon the Company’s current operating plan, it estimates that its $259.9 million of cash, cash equivalents, and investments at September 30, 2020 will be sufficient to fund its operating expenses and capital expenditure requirements through at least the 12 months following the date of this Quarterly Report on Form 10-Q.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	2 . Significant Accounting Policies Basis of Presentation The condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). During the third quarter of 2020, the Company incorporated Athira Pharma Australia PTY LTD in Australia and as of September 30, 2020, operations have yet to commence. Unaudited Interim Condensed Financial Statements The accompanying unaudited condensed balance sheet as of September 30, 2020, and condensed statements of operations and comprehensive loss, condensed statements of cash flows, and condensed statements of convertible preferred stock and stockholders’ deficit for the three and nine months ended September 30, 2020 and 2019, are unaudited. The balance sheet as of December 31, 2019 was derived from the audited financial statements as of and for the year ended December 31, 2019. The unaudited interim condensed financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2019, and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2020, and the condensed results of its operations and its cash flows for the three and nine months ended September 30, 2020 and 2019. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2020 and 2019 are also unaudited. The condensed results of operations for the three and nine months ended September 30, 2020 are not necessarily indicative of the results to be expected for the full year ending December 31, 2020 or any other period. These interim condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements as of and for the year ended December 31, 2019 included in its amended registration statement on Form S-1 (File No. 333-248428) filed with the SEC on September 17, 2020. Fair Value Measurements The carrying amounts of certain financial instruments, including cash, cash equivalents, investments, accounts payable and accrued expenses approximate their fair values due to the short-term nature of those amounts. The fair values of the grant liability to Washington Life Sciences Discovery Fund (“LSDF”), currently managed by the Washington State Department of Commerce, the derivative liability, and the convertible preferred stock warrant liability were estimated using level 3 unobservable inputs. Convertible Preferred Stock Warrant Liability Freestanding warrants to purchase shares of the Company’s convertible preferred stock are accounted for as liabilities at fair value, because the shares underlying the warrants contain contingent redemption features outside the control of the Company. Warrants classified as liabilities are recorded on the Company’s balance sheets at their fair value on the date of issuance and remeasured to fair value on each subsequent reporting period, with the changes in fair value recognized as a component of other income (expense), net in the accompanying statements of operations. The Company adjusted the liability for the final change in the fair value of these warrants immediately preceding their automatic exercise in connection with the Company’s IPO. Subsequently, the corresponding liability was reclassified to additional paid in capital. Short-term and Long-term Investments The Company generally invests its excess cash in investment grade short- to intermediate-term fixed income securities. Such investments are included in cash and cash equivalents, short-term investments, and long-term investments on the consolidated balance sheets, classified as available-for-sale, and reported at fair value with unrealized gains and losses included in accumulated other comprehensive loss. Realized gains and losses on the sale of these securities are recognized in net loss. The Company periodically evaluates whether declines in fair values of its investments below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the investment until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any investment before recovery of its amortized cost basis. Factors considered include quoted market prices, recent financial results and operating trends, implied values from any recent transactions or offers of investee securities, credit quality of debt instrument issuers, other publicly available information that may affect the value of the investments, duration and severity of the decline in value, and our strategy and intentions for holding the investment. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates include those used for fair value of assets and liabilities, accrued liabilities, valuation allowance for deferred tax assets, and stock-based compensation. Management evaluates related assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Research and Development Expenses Research and development expenses consist primarily of direct and indirect costs incurred for research activities, including development of our pipeline from the Company’s proprietary drug discovery platform (“ATH platform”). The Company’s drug discovery efforts and the development of its product candidates. Direct costs include laboratory materials and supplies, contracted research and manufacturing, clinical trial costs, consulting fees, and other expenses incurred to sustain the Company’s research and development program. Indirect costs include personnel-related expenses, consisting of employee salaries, related benefits, and stock-based compensation expense for employees engaged in research and development activities, and facilities and other expenses consisting of direct and allocated expenses for rent and depreciation and lab consumables. Research and development costs are expensed as incurred. In-licensing fees and other costs to acquire technologies used in research and development that have not yet received regulatory approval and that are not expected to have an alternative future use are expense when incurred. Non-refundable advance payments for goods and services that will be used over time for research and development are capitalized and recognized as goods are delivered or as the related services are performed. The Company estimates the period over which such services will be performed and the level of effort to be expended in each period. If actual timing of performance or the level of effort varies from the estimate, the Company adjusts the amounts recorded accordingly. The Company has not experienced any material differences between accrued or prepaid costs and actual costs since inception. Leases As discussed in Recently Adopted Accounting Standards Topic 842 - Leases The Company’s lease contains an option to extend the lease; lease terms are adjusted for these options only when it is reasonably certain the Company will exercise these options. The Company’s lease agreement does not contain residual value guarantees or covenants. The Company has made a policy election regarding its real estate leases not to separate nonlease components from lease components, to the extent they are fixed. Nonlease components that are not fixed are expensed as incurred as variable lease expense. The Company’s lease includes variable nonlease components, such as common-area maintenance costs. The Company has elected not to record on the balance sheet a lease that has a lease term of 12 months or less and does not contain a purchase option that the Company is reasonably certain to exercise. The Company accounts for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term. Lease expense is recognized within operating expenses on a straight-line basis over the terms of the lease. Incentives granted under the Company’s facilities lease, including rent holidays, are recognized as adjustments to lease expense on a straight-line basis over the term of the lease. Stock-based Compensation The Company measures compensation expense for all stock-based payments to employees, officers and directors based on the estimated fair value of the award at the grant date. For stock options, the Company estimates the grant date fair value of each option award using the Black-Scholes option-pricing model. Compensation expense is recognized over the requisite service period on a straight-line basis. Forfeitures are recognized as they occur. The Company records compensation expense for stock option grants subject to performance-based milestone vesting using the accelerated attribution method over the remaining service period when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the relative satisfaction of the performance conditions as of the reporting date. The Company adopted Accounting Standards Update (“ASU”) 2018-07 as of January 1, 2020. As a result, stock-based payments issued to non-employees prior to January 1, 2020 have been recorded at their fair values as of the transition date and are no longer subject to periodic adjustments as the underlying equity instruments vest. Any remaining compensation expense is recognized over the remaining vesting term on a straight-line basis, which reflects the service period, based on the fair value as of January 1, 2020. Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company. Segments The Company has determined that it operates and manages one operating segment, which is the business of developing and commercializing therapeutics. The Company’s chief operating decision maker, its chief executive officer, reviews financial information on an aggregate basis for the purpose of allocating resources. Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (“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 use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it is (a) no longer an emerging growth company or (b) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act, unless early adoption is permitted. As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) Leases (Topic 842) Targeted Improvements In adopting the new standard, the Company utilized certain practical expedients available. These practical expedients include waiving reassessment of 1) whether any expired or existing contracts are or contain leases; 2) lease classification of expired or existing leases; and 3) initial direct costs for existing leases. The Company also elected to use hindsight in determining the lease term and in assessing impairment of its ROU assets. Furthermore, the Company has made a policy decision regarding its real estate leases not to separate nonlease components from lease components, to the extent they are fixed. The Company has also elected not to record on the balance sheet a lease that has a lease term of 12 months or less and does not contain a purchase option that the Company is reasonably certain to exercise. The standard had a material impact on the Company’s unaudited condensed balance sheets but did not have a material impact on its unaudited condensed statements of operations or unaudited condensed statements of cash flows. The most significant impact was the recognition of $1.0 million and $1.0 million of operating lease ROU assets and liabilities, respectively. Refer to Note 8, Leases, for additional information regarding leases. In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 326) Improvements to Nonemployee Share-Based Payment Accounting In August 2018, the FASB issued ASU 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement Recent Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments: Credit Losses (Topic 326) Although there were several other new accounting pronouncements issued or proposed by the FASB, we do not believe any of these have had or will have material impact on our condensed consolidated financial statements.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value	3 . Fair Value The Company has certain assets and liabilities that are measured at fair value on a recurring basis according to a fair value hierarchy that prioritizes the inputs, assumptions and valuation techniques used to measure fair value. The three levels of the fair value hierarchy are: Level 1 —Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 —Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly. Level 3 —Inputs are generally unobservable and reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are determined using model-based techniques, including probability-based simulation methodologies. The determination of a financial instrument’s level within the fair value hierarchy is based on an assessment of the lowest level of any input that is significant to the fair value measurement. The Company considers observable data to be market data, which is readily available, regularly distributed or updated, reliable and verifiable, not proprietary, and provided by independent sources that are actively involved in the relevant market. The following table reflects the Company’s financial asset balances measured on a recurring basis as of September 30, 2020 (in thousands): Level Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market fund 1 $ 66,596 — — $ 66,596 Commercial paper 2 70,392 — (3 ) 70,389 U.S. government debt and agency securities 2 835 — — 835 U.S. treasury bills 2 14,999 — — 14,999 Total cash equivalents $ 152,822 $ — $ (3 ) $ 152,819 Short-term investments: Commercial paper 2 30,393 2 (1 ) 30,394 U.S. government debt and agency securities 2 29,220 7 — 29,227 Corporate bonds 2 926 — — 926 Total short-term investments $ 60,539 $ 9 $ (1 ) $ 60,547 Long-term investments: U.S. government debt and agency securities 2 32,634 11 (9 ) 32,636 U. S. treasury bills 2 1,020 — — 1,020 Total long-term investments $ 33,654 $ 11 $ (9 ) $ 33,656 The Company evaluated its investments for other-than-temporary impairment and considers the decline in market value for the securities to be primarily attributable to current economic and market conditions. For the investments, it is not more-likely-than-not that the Company will be required to sell the investments, and the Company does not intend to do so prior to the recovery of the amortized cost basis. Prior to the IPO, the Company’s level 3 financial liabilities carried at fair value and remeasured on a recurring basis are the grant liability, derivative liability, and the convertible preferred stock warrant liability. In the third quarter the Company recorded an additional $464,000 to bring the total grant liability to $1.5 million as the Company’s IPO triggered the repayment obligation (see Note 6), and the derivative was settled upon the Company’s conversion of its convertible notes in May 2020 (see Note 7). The losses resulting from the change in fair value of the grant liability, the bifurcated conversion and redemption features related to the derivative liability, and the convertible preferred stock warrant liability are classified as other income (expense), net in the accompanying condensed consolidated statements of operations and comprehensive loss. Changes in any of the assumptions related to the unobservable inputs identified may change the fair value of these instruments. For example, an increase in interest rates would generally correspond to a decrease in the fair value of the liabilities. The following table presents the activity for the grant liability for the nine months ended September 30, 2020 and year ended December 31, 2019 (in thousands): Nine Months Ended September 30, 2020 Year Ended December 31, 2019 Fair value at beginning of period $ 1,036 $ 936 Change in fair value of grant liability 464 100 Fair value at end of period $ 1,500 $ 1,036 The following table presents the activity for the derivative liability for the nine months ended September 30, 2020 and year ended December 31, 2019 (in thousands): Nine Months Ended September 30, 2020 Year Ended December 31, 2019 Fair value at beginning of period $ 999 $ 539 Derivative liability recorded upon issuance of convertible notes 774 389 Change in fair value of derivative liability 132 71 Derivative liability settled upon conversion of convertible notes (1,905 ) — Fair value at end of period $ — $ 999 The following table presents the activity for the convertible preferred stock warrant liability Nine Months Ended September 30, 2020 Fair value at beginning of period $ — Recognition of convertible preferred stock warrant liability 364 Change in fair value 641 Settlement upon IPO (1,005 ) Fair value at end of period $ — Prior to the IPO, the activity for the convertible preferred stock warrant liability presented in the table above was shown in the Company’s financial statements as level 3. Following the IPO, the preferred stock warrant liability was revalued based on the IPO price of $17.00 per share.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	4 . Accrued Expenses Accrued expenses consisted of the following (in thousands): As of September 30, 2020 As of December 31, 2019 Research and development expenses $ 1,672 $ 536 Employee compensation and benefits 229 230 Professional services and other 224 86 Total accrued expenses $ 2,125 $ 852

Other Income (Expense), Net

Other Income (Expense), Net	9 Months Ended
	Sep. 30, 2020
Other Income And Expenses [Abstract]
Other Income (Expense), Net	5 . Other Income (Expense), Net Other income (expense), net consisted of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Part the Cloud research grant $ — $ 189 $ 22 $ 472 Interest and other income 35 12 45 44 Interest expense — (98 ) (366 ) (236 ) Change in fair value of derivative liability — (77 ) (132 ) (84 ) Change in fair value of grant liability (453 ) (21 ) (464 ) (51 ) Change in convertible preferred stock warrant liability (641 ) — (641 ) — Gain on extinguishment of convertible notes — — 199 — Total other income (expense), net $ (1,059 ) $ 5 $ (1,337 ) $ 145

Significant Agreements

Significant Agreements	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Significant Agreements	6 Washington State University (“WSU”) License Agreement In December 2011, the Company entered into an exclusive license agreement with sublicensing terms with Washington State University Research Fund (“WSURF”), which, after the dissolution of WSURF in 2013, was superseded by an amended and restated exclusive license agreement with sublicensing terms between the Company and Washington State University (“WSU”) in 2015. Under this agreement, the Company has an exclusive license to make, use, sell, and offer for sale a chemical compound that forms the underlying technology of the drug therapies being developed by the Company. To keep in good standing, the agreement requires the Company to meet certain development milestones and pay an annual maintenance fee. All contractual requirements have been met as of September 30, 2020. As of September 30, 2020, the Phase 2 clinical trial milestone had been reached and a $50,000 liability to WSU was recorded. The Company may also be obligated to pay the following if the related milestones are reached: • $300,000 – At initiation of the first Phase 3 clinical trial in the United States, European Union or Japan for the first licensed product. • $600,000 – Marketing approval in the United States, European Union or Japan for the first licensed product. Under the terms of the agreement, the Company will pay a royalty in the mid-single digits of net sales, with the first $100,000 of net sales being exempt from royalty payment, and annual minimum royalty payments of $25,000 beginning after the first commercial sale of a licensed product. As of September 30, 2020, the Company had not incurred a royalty obligation under this agreement. Additionally, the agreement allows the Company to sublicense the rights conveyed by the agreement, subject to additional payments to WSU for sublicense consideration received. Such amounts are dependent on the terms of the underlying sublicense and range from the mid-single digits to mid-teens of any non-sales based payments received, and low twenties of net sales based sublicense royalties. As of September 30, 2020, the Company has not entered into or incurred any liability from a sublicense agreement. Grant Liability In 2014 and 2015, the Company received $250,000 and $500,000, respectively, from LSDF under the terms of two matching grant award agreements. In connection with the agreements, LSDF retained the right to receive cash payments of 2.0 times the amounts received, or $1.5 million, upon the occurrence of specified triggering events, including: • receipt of license revenue, sales revenue, or consideration related to the underlying IP; • transfers the underlying IP without receiving consideration; • relocation of the Company from Washington state; • completion of an initial public offering; • a third-party acquisition of a controlling interest in the Company, and; • termination of the agreements. To appropriately capture the economics of this arrangement, the grant liability is accounted for under ASC 825-10, Financial Instruments −Overall The estimated fair value of the grant liability was $1.0 million as of December 31, 2019. The consummation of the Company’s IPO in September 2020 was a triggering event under the terms of the grant and the liability was remeasured to the pay-off amount of $1.5 million as of September 30, 2020. The changes in the fair value of the liability resulted in expense of approximately $453,000 and $21,000 for the three months ended September 30, 2020 and 2019, respectively, and $464,000 and $51,000 for the nine months ended September 30, 2020 and 2019, respectively, which were included in other income (expense), net in the accompanying condensed consolidated statements of operations and comprehensive loss.

Debt

Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt	7 Convertible Notes The Company issued unsecured convertible notes with an aggregate principal amount of $1.7 million in 2020. Previously, the Company issued unsecured convertible notes with aggregate principal amounts of $884,000 and $1.3 million and in 2019 and 2018, respectively. The notes accrue interest at a rate of 5% per year and mature in December 2021, unless earlier converted. No principal or interest is payable prior to maturity as the convertible notes and any accrued interest will automatically convert upon a qualified financing event at a conversion price equal to 85% of the price per share of the qualified financing. Holders may also elect to convert their notes to shares of common stock upon the maturity of the notes at the then fair value of common stock. If the Company experiences a change in control, holders may either convert the outstanding principal amount plus any accrued interest into shares of common stock at the then fair value of common stock or may require the Company to repurchase the notes in cash at a price equal to 200% of the outstanding principal amount plus any accrued interest. Certain conversion and redemption features as described above were determined to be an embedded derivative requiring bifurcation and separate accounting in accordance with ASC 815, Derivatives and Hedging In May 2020, the outstanding principal balance of the convertible notes of $3.8 million and accrued interest of $160,000 converted into 512,858 shares of Series B-1 convertible preferred stock. The excess of the carrying value of the convertible notes and the derivative liability over the fair value of the Series B-1 convertible preferred stock at conversion resulted in a gain upon extinguishment of $199,000. Paycheck Protection Program The Company received a loan of $215,000 from the U.S. Small Business Administration Paycheck Protection Program (“PPP”) in April 2020. The PPP loans are intended to assist companies impacted by the novel coronavirus disease (“COVID-19”) pandemic to fund certain types of expenditures, including payroll costs, rent and utility payments. PPP loans and any accrued interest may be forgiven to the extent that all employees are retained, proceeds are used within eight weeks of receipt, and if at least 75% of the loan amount utilized was for payroll costs. The loan bears interest at a rate of 1%, and any portion of the loan not forgiven and any accrued interest thereon must be repaid within two years. The loan was fully repaid in June 2020.

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	8 Operating Leases The Company has an operating lease for laboratory and office facilities in Bothell, Washington that expires in August 2027. The initial term of the lease is seven years and the Company has an option to extend the lease for an additional five years that it is not reasonably certain to exercise. As of September 30, 2020, the remaining lease term for the Company’s operating lease was 6.9 years. The Company discounted future operating lease payments using an incremental borrowing rate of 8.2%. Additionally, the Company has a lease agreement for laboratory and office facilities at the University of Washington in Seattle, Washington with an initial term of 12 months for which the Company recognizes expense on a straight-line basis within operating expenses. As of September 30, 2020, the Company was not party to any finance leases. The following table reconciles the Company’s undiscounted operating lease cash flows to its operating lease liability (in thousands): As of September 30, 2020 Remaining 2020 $ — 2021 234 2022 261 2023 269 2024 277 2025 and thereafter 779 Total undiscounted lease payments 1,820 Present value adjustment for minimum lease commitments (457 ) Tenant improvement allowance receivable (391 ) Net lease liability $ 972 Operating lease expense was $34,000 for the three and nine months ended September 30, 2020. The Company did not incur variable lease expense for operating leases during the three and nine months ended September 30, 2020. Rent expense recognized for short term leases was $18,000 and $57,000 for the three and nine months ended September 30, 2020, respectively. Cash paid for amounts included in the measurement of the lease liability for the nine months ended September 30, 2020 was $21,000.

Convertible Preferred Stock

Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Convertible Preferred Stock	9 . Convertible Preferred Stock Convertible preferred stock as of December 31, 2019 consisted of the following (in thousands, except share amounts): Convertible Shares Issued and Aggregate Liquidation Preferred Stock Authorized Outstanding Carrying Value Preference Series A 1,714,963 1,534,885 $ 15,163 $ 15,215 Series A-1 1,082,501 1,082,501 1,888 1,073 Total 2,797,464 2,617,386 $ 17,051 $ 16,288 In May and June 2020, the Company issued an aggregate of 9,372,765 shares of its Series B convertible preferred stock at a purchase price of $9.12 per share for aggregate proceeds of $81.6 million, net of offering costs. The Company issued warrants to purchase 2,343,168 shares of its common stock, of which 688,067 were exercised concurrently with the shares of Series B convertible preferred stock issuance, for net proceeds of $55,000. In addition, the Company issued warrants to purchase 127,481 shares of its Series B convertible preferred stock at a purchase price of $9.12 per share. The Series B convertible preferred stock financing triggered the automatic conversion of the Company’s outstanding convertible promissory notes into 512,858 shares of Series B-1 convertible preferred stock based on a price of $7.752 per share (85% of the $9.12 original issuance price of the Series B convertible preferred stock). In September 2020, upon the consummation of the Company’s IPO, all outstanding shares of convertible preferred stock converted into 12,503,009 shares of common stock.

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Common Stock	10. Common Stock Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and if declared by the board of directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No cash dividends have been declared by the board of directors from inception. The Company has reserved the following shares of common stock for future issuance, on an as-converted basis, as follows: As of September 30, 2020 As of December 31, 2019 Convertible preferred stock — 2,617,386 Stock options outstanding 1,927,428 1,514,770 Shares available for future grant under the 2020 Equity Incentive Plan 3,790,279 399,737 Shares available for future grant under the Employee Stock Purchase Plan 323,000 — Common stock warrants — 3,310 Total 6,040,707 4,535,203

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	11. Stock-based Compensation Stock‑based compensation expense recognized was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 43 $ 13 $ 62 $ 42 General and administrative 68 56 156 147 Total stock-based compensation expense $ 111 $ 69 $ 218 $ 189 Valuation Assumptions The fair value of stock options was determined using the Black-Scholes option-pricing model and the assumptions below. Each of these inputs is subjective and generally required significant judgment. • Fair Value of Common Stock —The grant date fair market value of the shares of common stock underlying stock options has historically been determined by the Company’s board of directors. Because previously there was no public market for the Company’s common stock, the board of directors exercised reasonable judgment and considered a number of objective and subjective factors to determine the best estimate of the fair market value, which include contemporaneous valuations performed by an independent third party, important developments in the Company’s operations, sales of convertible preferred stock, the rights, preferences and privileges of its convertible preferred stock relative to those of its common stock, lack of marketability of its common stock, actual operating results, financial performance, the progress of clinical development, the likelihood of achieving a liquidity event for its security holders, the trends, development and conditions in the life sciences and biotechnology sectors, the economy in general, and the stock price performance and volatility of comparable public companies. • Risk-Free Interest Rate —The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of the option. • Expected Volatility —Because the Company was previously privately held and did not have any trading history for its common stock, the expected volatility was estimated based on the average volatility for comparable publicly traded life sciences companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on the similar size, stage in life cycle or area of specialty. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. • Expected Term —The expected term represents the period that the stock-based awards are expected to be outstanding and is determined using the simplified method (based on the midpoint between the vesting date and the end of the contractual term) as the Company has limited history of relevant stock option exercise activity. • Expected Dividend Yield —The Company has never paid dividends on its common stock and has no plans to pay dividends going forward. Therefore, it used an expected dividend yield of zero. The fair value of each stock option was estimated using the Black‑Scholes option‑pricing model with the following weighted-average assumptions: Nine Months Ended September 30, 2020 2019 Risk-free interest rate 0.49 % 1.58 % Expected volatility 80.11 % 74.59 % Expected term (in years) 6.93 6.59 Expected dividend yield — — The weighted-average grant-date fair value of options granted to employees and directors during the nine months ended September 30, 2020 and 2019 were $2.1 million and $259,000 respectively. The weighted-average grant-date fair value of options granted to advisors during the nine months ended September 30, 2020 was $727,000. The remeasured weighted-average fair value of options granted to advisors during the nine months ended September 30, 2019 was $46,000. Stock Option Activity A summary of option activity for the nine months ended September 30, 2020 was as follows: Available for Grant Shares Weighted- Average Exercise price per Share Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Balance at December 31, 2019 399,737 1,514,770 $ 1.03 7.16 $ 500 Authorized 4,343,534 — Granted (994,293 ) 994,293 16.20 Exercised — (540,334 ) 1.00 Forfeited/expired 41,301 (41,301 ) 1.35 Balance at September 30, 2020 3,790,279 1,927,428 $ 8.85 8.18 $ 18,521 Expected to vest 1,298,059 $ 12.71 9.52 $ 7,460 Options exercisable 629,373 $ 0.89 5.43 $ 11,061 The total fair value of options granted to employees, directors, and advisors that vested during the nine months ended September 30, 2020 was $219,000, which included $144,000 for options granted to employees and directors and $75,000 for options granted to advisors. The total fair value of options that vested during the nine months ended September 30, 2019 was $123,000, which included $64,000 for options granted to employees and directors and $59,000 for options granted to advisors. The aggregate intrinsic value in the table above is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the Company’s common stock underlying all options that were in-the-money at September 30, 2020. The aggregate intrinsic value of options exercised was $9.4 million and $4,000 during the nine months ended September 30, 2020 and 2019, respectively, determined as of the date of option exercise. As of September 30, 2020, there was $2.9 million of total unrecognized compensation cost related to unvested stock options. The Company expects to recognize this cost over a remaining weighted-average period of 1.95 years. The Company utilizes newly issued shares to satisfy option exercises. Stock options outstanding and exercisable consisted of the following at September 30, 2020: Employees and Directors Non-employees Exercise Price ($) Shares Outstanding Shares Exercisable Shares Outstanding Shares Exercisable 0.16 75,660 75,660 12,611 12,611 0.48 162,353 162,353 — — 1.00 — — 37,830 37,830 1.04 70,933 70,933 31,525 31,525 1.19 52,645 38,878 34,677 34,677 1.31 63,050 63,050 — — 1.35 294,754 27,529 116,642 63,049 1.49 31,525 10,508 — — 17.00 747,770 770 195,453 — Total 1,498,690 449,681 428,738 179,692 Restricted Stock Award Activity In 2018, the Company issued a restricted stock award (“RSA”) to an advisor under the 2014 Plan. The restricted stock award vests over three years and requires continued service to the Company during the vesting period. The vesting provisions of individual awards may vary as approved by the board of directors. If continued service terminates for any reason, the Company has the right to repurchase the unvested shares for no consideration. Shares subject to repurchase as of September 30, 2020 and December 31, 2019 were 4,204 shares and 8,407 shares, respectively, all of which were related to non-employee RSAs. A summary of RSA activity for the nine months ended September 30, 2020 was Share Equivalent Weighted- Average Grant Date Fair Value Non-vested at December 31, 2019 8,407 1.35 Granted — — Vested (4,203 ) 1.35 Non-vested at September 30, 2020 4,204 $ 1.35

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	12. Net Loss Per Share Attributable to Common Stockholders The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive: Nine Months Ended September 30, 2020 2019 Convertible preferred stock on an as-converted basis — 2,617,386 Unvested RSAs 4,204 8,407 Stock options to purchase common stock 1,927,428 1,498,377 Common stock warrants — 3,310 Total 1,931,632 4,127,480

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events Exercise of Underwriters’ Option On October 16, 2020, the Company sold an additional 1,397,712 shares of common stock to the underwriters of the IPO upon partial exercise of the underwriters’ option to purchase additional shares at the initial public offering price of $17.00 per share, less underwriting discounts and commissions, resulting in net proceeds to the Company of approximately $22.1 million.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). During the third quarter of 2020, the Company incorporated Athira Pharma Australia PTY LTD in Australia and as of September 30, 2020, operations have yet to commence.
Unaudited Interim Condensed Financial Statements	Unaudited Interim Condensed Financial Statements The accompanying unaudited condensed balance sheet as of September 30, 2020, and condensed statements of operations and comprehensive loss, condensed statements of cash flows, and condensed statements of convertible preferred stock and stockholders’ deficit for the three and nine months ended September 30, 2020 and 2019, are unaudited. The balance sheet as of December 31, 2019 was derived from the audited financial statements as of and for the year ended December 31, 2019. The unaudited interim condensed financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2019, and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2020, and the condensed results of its operations and its cash flows for the three and nine months ended September 30, 2020 and 2019. The financial data and other information disclosed in these notes related to the three and nine months ended September 30, 2020 and 2019 are also unaudited. The condensed results of operations for the three and nine months ended September 30, 2020 are not necessarily indicative of the results to be expected for the full year ending December 31, 2020 or any other period. These interim condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements as of and for the year ended December 31, 2019 included in its amended registration statement on Form S-1 (File No. 333-248428) filed with the SEC on September 17, 2020.
Fair Value Measurements	Fair Value Measurements The carrying amounts of certain financial instruments, including cash, cash equivalents, investments, accounts payable and accrued expenses approximate their fair values due to the short-term nature of those amounts. The fair values of the grant liability to Washington Life Sciences Discovery Fund (“LSDF”), currently managed by the Washington State Department of Commerce, the derivative liability, and the convertible preferred stock warrant liability were estimated using level 3 unobservable inputs.
Convertible Preferred Stock Warrant Liability	Convertible Preferred Stock Warrant Liability Freestanding warrants to purchase shares of the Company’s convertible preferred stock are accounted for as liabilities at fair value, because the shares underlying the warrants contain contingent redemption features outside the control of the Company. Warrants classified as liabilities are recorded on the Company’s balance sheets at their fair value on the date of issuance and remeasured to fair value on each subsequent reporting period, with the changes in fair value recognized as a component of other income (expense), net in the accompanying statements of operations. The Company adjusted the liability for the final change in the fair value of these warrants immediately preceding their automatic exercise in connection with the Company’s IPO. Subsequently, the corresponding liability was reclassified to additional paid in capital.
Short-term and Long-term Investments	Short-term and Long-term Investments The Company generally invests its excess cash in investment grade short- to intermediate-term fixed income securities. Such investments are included in cash and cash equivalents, short-term investments, and long-term investments on the consolidated balance sheets, classified as available-for-sale, and reported at fair value with unrealized gains and losses included in accumulated other comprehensive loss. Realized gains and losses on the sale of these securities are recognized in net loss. The Company periodically evaluates whether declines in fair values of its investments below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the investment until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any investment before recovery of its amortized cost basis. Factors considered include quoted market prices, recent financial results and operating trends, implied values from any recent transactions or offers of investee securities, credit quality of debt instrument issuers, other publicly available information that may affect the value of the investments, duration and severity of the decline in value, and our strategy and intentions for holding the investment.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Estimates include those used for fair value of assets and liabilities, accrued liabilities, valuation allowance for deferred tax assets, and stock-based compensation. Management evaluates related assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist primarily of direct and indirect costs incurred for research activities, including development of our pipeline from the Company’s proprietary drug discovery platform (“ATH platform”). The Company’s drug discovery efforts and the development of its product candidates. Direct costs include laboratory materials and supplies, contracted research and manufacturing, clinical trial costs, consulting fees, and other expenses incurred to sustain the Company’s research and development program. Indirect costs include personnel-related expenses, consisting of employee salaries, related benefits, and stock-based compensation expense for employees engaged in research and development activities, and facilities and other expenses consisting of direct and allocated expenses for rent and depreciation and lab consumables. Research and development costs are expensed as incurred. In-licensing fees and other costs to acquire technologies used in research and development that have not yet received regulatory approval and that are not expected to have an alternative future use are expense when incurred. Non-refundable advance payments for goods and services that will be used over time for research and development are capitalized and recognized as goods are delivered or as the related services are performed. The Company estimates the period over which such services will be performed and the level of effort to be expended in each period. If actual timing of performance or the level of effort varies from the estimate, the Company adjusts the amounts recorded accordingly. The Company has not experienced any material differences between accrued or prepaid costs and actual costs since inception.
Leases	Leases As discussed in Recently Adopted Accounting Standards Topic 842 - Leases The Company’s lease contains an option to extend the lease; lease terms are adjusted for these options only when it is reasonably certain the Company will exercise these options. The Company’s lease agreement does not contain residual value guarantees or covenants. The Company has made a policy election regarding its real estate leases not to separate nonlease components from lease components, to the extent they are fixed. Nonlease components that are not fixed are expensed as incurred as variable lease expense. The Company’s lease includes variable nonlease components, such as common-area maintenance costs. The Company has elected not to record on the balance sheet a lease that has a lease term of 12 months or less and does not contain a purchase option that the Company is reasonably certain to exercise. The Company accounts for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term. Lease expense is recognized within operating expenses on a straight-line basis over the terms of the lease. Incentives granted under the Company’s facilities lease, including rent holidays, are recognized as adjustments to lease expense on a straight-line basis over the term of the lease.
Stock-based Compensation	Stock-based Compensation The Company measures compensation expense for all stock-based payments to employees, officers and directors based on the estimated fair value of the award at the grant date. For stock options, the Company estimates the grant date fair value of each option award using the Black-Scholes option-pricing model. Compensation expense is recognized over the requisite service period on a straight-line basis. Forfeitures are recognized as they occur. The Company records compensation expense for stock option grants subject to performance-based milestone vesting using the accelerated attribution method over the remaining service period when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the relative satisfaction of the performance conditions as of the reporting date. The Company adopted Accounting Standards Update (“ASU”) 2018-07 as of January 1, 2020. As a result, stock-based payments issued to non-employees prior to January 1, 2020 have been recorded at their fair values as of the transition date and are no longer subject to periodic adjustments as the underlying equity instruments vest. Any remaining compensation expense is recognized over the remaining vesting term on a straight-line basis, which reflects the service period, based on the fair value as of January 1, 2020.
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company.
Segments	Segments The Company has determined that it operates and manages one operating segment, which is the business of developing and commercializing therapeutics. The Company’s chief operating decision maker, its chief executive officer, reviews financial information on an aggregate basis for the purpose of allocating resources.
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 (“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 use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it is (a) no longer an emerging growth company or (b) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act, unless early adoption is permitted. As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.
Recently Adopted Accounting Pronouncements Adopted and Not Yet Adopted	Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) Leases (Topic 842) Targeted Improvements In adopting the new standard, the Company utilized certain practical expedients available. These practical expedients include waiving reassessment of 1) whether any expired or existing contracts are or contain leases; 2) lease classification of expired or existing leases; and 3) initial direct costs for existing leases. The Company also elected to use hindsight in determining the lease term and in assessing impairment of its ROU assets. Furthermore, the Company has made a policy decision regarding its real estate leases not to separate nonlease components from lease components, to the extent they are fixed. The Company has also elected not to record on the balance sheet a lease that has a lease term of 12 months or less and does not contain a purchase option that the Company is reasonably certain to exercise. The standard had a material impact on the Company’s unaudited condensed balance sheets but did not have a material impact on its unaudited condensed statements of operations or unaudited condensed statements of cash flows. The most significant impact was the recognition of $1.0 million and $1.0 million of operating lease ROU assets and liabilities, respectively. Refer to Note 8, Leases, for additional information regarding leases. In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 326) Improvements to Nonemployee Share-Based Payment Accounting In August 2018, the FASB issued ASU 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement Recent Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments: Credit Losses (Topic 326) Although there were several other new accounting pronouncements issued or proposed by the FASB, we do not believe any of these have had or will have material impact on our condensed consolidated financial statements.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2020
Schedule of Fair Value of Cash Equivalents, Short-term Investments and Long-term Investments	The following table reflects the Company’s financial asset balances measured on a recurring basis as of September 30, 2020 (in thousands): Level Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market fund 1 $ 66,596 — — $ 66,596 Commercial paper 2 70,392 — (3 ) 70,389 U.S. government debt and agency securities 2 835 — — 835 U.S. treasury bills 2 14,999 — — 14,999 Total cash equivalents $ 152,822 $ — $ (3 ) $ 152,819 Short-term investments: Commercial paper 2 30,393 2 (1 ) 30,394 U.S. government debt and agency securities 2 29,220 7 — 29,227 Corporate bonds 2 926 — — 926 Total short-term investments $ 60,539 $ 9 $ (1 ) $ 60,547 Long-term investments: U.S. government debt and agency securities 2 32,634 11 (9 ) 32,636 U. S. treasury bills 2 1,020 — — 1,020 Total long-term investments $ 33,654 $ 11 $ (9 ) $ 33,656
Grant Liability
Schedule of Fair Value Liabilities, Activity	The following table presents the activity for the grant liability for the nine months ended September 30, 2020 and year ended December 31, 2019 (in thousands): Nine Months Ended September 30, 2020 Year Ended December 31, 2019 Fair value at beginning of period $ 1,036 $ 936 Change in fair value of grant liability 464 100 Fair value at end of period $ 1,500 $ 1,036
Derivative Liability
Schedule of Fair Value Liabilities, Activity	The following table presents the activity for the derivative liability for the nine months ended September 30, 2020 and year ended December 31, 2019 (in thousands): Nine Months Ended September 30, 2020 Year Ended December 31, 2019 Fair value at beginning of period $ 999 $ 539 Derivative liability recorded upon issuance of convertible notes 774 389 Change in fair value of derivative liability 132 71 Derivative liability settled upon conversion of convertible notes (1,905 ) — Fair value at end of period $ — $ 999
Convertible Preferred Stock Warrant Liability
Schedule of Fair Value Liabilities, Activity	The following table presents the activity for the convertible preferred stock warrant liability Nine Months Ended September 30, 2020 Fair value at beginning of period $ — Recognition of convertible preferred stock warrant liability 364 Change in fair value 641 Settlement upon IPO (1,005 ) Fair value at end of period $ —

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following (in thousands): As of September 30, 2020 As of December 31, 2019 Research and development expenses $ 1,672 $ 536 Employee compensation and benefits 229 230 Professional services and other 224 86 Total accrued expenses $ 2,125 $ 852

Other Income (Expense), Net (Ta

Other Income (Expense), Net (Tables)	9 Months Ended
	Sep. 30, 2020
Other Income And Expenses [Abstract]
Schedule of Other Income (Expense), Net	Other income (expense), net consisted of the following (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Part the Cloud research grant $ — $ 189 $ 22 $ 472 Interest and other income 35 12 45 44 Interest expense — (98 ) (366 ) (236 ) Change in fair value of derivative liability — (77 ) (132 ) (84 ) Change in fair value of grant liability (453 ) (21 ) (464 ) (51 ) Change in convertible preferred stock warrant liability (641 ) — (641 ) — Gain on extinguishment of convertible notes — — 199 — Total other income (expense), net $ (1,059 ) $ 5 $ (1,337 ) $ 145

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Reconciliation of Undiscounted Operating Lease Cash Flows to Operating Lease Liability Payments	The following table reconciles the Company’s undiscounted operating lease cash flows to its operating lease liability (in thousands): As of September 30, 2020 Remaining 2020 $ — 2021 234 2022 261 2023 269 2024 277 2025 and thereafter 779 Total undiscounted lease payments 1,820 Present value adjustment for minimum lease commitments (457 ) Tenant improvement allowance receivable (391 ) Net lease liability $ 972

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Convertible Preferred Stock	Convertible preferred stock as of December 31, 2019 consisted of the following (in thousands, except share amounts): Convertible Shares Issued and Aggregate Liquidation Preferred Stock Authorized Outstanding Carrying Value Preference Series A 1,714,963 1,534,885 $ 15,163 $ 15,215 Series A-1 1,082,501 1,082,501 1,888 1,073 Total 2,797,464 2,617,386 $ 17,051 $ 16,288

Common Stock (Tables)

Common Stock (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Future Issuance	The Company has reserved the following shares of common stock for future issuance, on an as-converted basis, as follows: As of September 30, 2020 As of December 31, 2019 Convertible preferred stock — 2,617,386 Stock options outstanding 1,927,428 1,514,770 Shares available for future grant under the 2020 Equity Incentive Plan 3,790,279 399,737 Shares available for future grant under the Employee Stock Purchase Plan 323,000 — Common stock warrants — 3,310 Total 6,040,707 4,535,203

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation Expense Recognized	Stock‑based compensation expense recognized was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 43 $ 13 $ 62 $ 42 General and administrative 68 56 156 147 Total stock-based compensation expense $ 111 $ 69 $ 218 $ 189
Weighted-Average Assumptions used in Estimating Fair Value of each Stock Options using Black-Scholes Option-Pricing Model	The fair value of each stock option was estimated using the Black‑Scholes option‑pricing model with the following weighted-average assumptions: Nine Months Ended September 30, 2020 2019 Risk-free interest rate 0.49 % 1.58 % Expected volatility 80.11 % 74.59 % Expected term (in years) 6.93 6.59 Expected dividend yield — —
Summary of Option Activity	A summary of option activity for the nine months ended September 30, 2020 was as follows: Available for Grant Shares Weighted- Average Exercise price per Share Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Balance at December 31, 2019 399,737 1,514,770 $ 1.03 7.16 $ 500 Authorized 4,343,534 — Granted (994,293 ) 994,293 16.20 Exercised — (540,334 ) 1.00 Forfeited/expired 41,301 (41,301 ) 1.35 Balance at September 30, 2020 3,790,279 1,927,428 $ 8.85 8.18 $ 18,521 Expected to vest 1,298,059 $ 12.71 9.52 $ 7,460 Options exercisable 629,373 $ 0.89 5.43 $ 11,061
Summary of Stock Options Outstanding and Exercisable	Stock options outstanding and exercisable consisted of the following at September 30, 2020: Employees and Directors Non-employees Exercise Price ($) Shares Outstanding Shares Exercisable Shares Outstanding Shares Exercisable 0.16 75,660 75,660 12,611 12,611 0.48 162,353 162,353 — — 1.00 — — 37,830 37,830 1.04 70,933 70,933 31,525 31,525 1.19 52,645 38,878 34,677 34,677 1.31 63,050 63,050 — — 1.35 294,754 27,529 116,642 63,049 1.49 31,525 10,508 — — 17.00 747,770 770 195,453 — Total 1,498,690 449,681 428,738 179,692
Summary of RSA Activity	A summary of RSA activity for the nine months ended September 30, 2020 was Share Equivalent Weighted- Average Grant Date Fair Value Non-vested at December 31, 2019 8,407 1.35 Granted — — Vested (4,203 ) 1.35 Non-vested at September 30, 2020 4,204 $ 1.35

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive: Nine Months Ended September 30, 2020 2019 Convertible preferred stock on an as-converted basis — 2,617,386 Unvested RSAs 4,204 8,407 Stock options to purchase common stock 1,927,428 1,498,377 Common stock warrants — 3,310 Total 1,931,632 4,127,480

Description of Business - Addit

Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands

Sep. 22, 2020USD ($)$ / sharesshares

Sep. 16, 2020USD ($)shares

Sep. 11, 2020

Sep. 30, 2020USD ($)shares

Sep. 30, 2020USD ($)shares

Sep. 30, 2020USD ($)shares

Sep. 23, 2020shares

Jun. 30, 2020shares

Dec. 31, 2019shares

Sep. 30, 2019shares

Jun. 30, 2019shares

Dec. 31, 2018shares

Description Of Business [Line Items]

Reverse stock split, description

On September 11, 2020, the Company effected a one-for-7.9302 reverse split of its issued and outstanding common stock, convertible preferred stock, warrants, and stock options.

Reverse stock split conversion ratio

0.1261

Net proceeds from public offering | $

$ 187,224

Loss on final re-measurement of fair value of warrant liability | $

$ 641

$ 641

Temporary equity shares outstanding

0

0

0

2,617,386

Net cash proceeds from issuance of convertible preferred stock, common stock warrants, and convertible notes | $

$ 288,500

Cash, cash equivalents, and investments | $

$ 259,900

$ 259,900

$ 259,900

Common Stock Warrants

Description Of Business [Line Items]

Common shares issued upon exercise of warrants

1,085,334

Series B Convertible Preferred Stock Warrant

Description Of Business [Line Items]

Common shares issued upon exercise of warrants

59,093

Series B Convertible Preferred Stock Warrant | Other Income (Expense), Net

Description Of Business [Line Items]

Loss on final re-measurement of fair value of warrant liability | $

$ 600

Convertible Preferred Stock, Common Stock Warrants Or Series B Convertible Preferred Stock Warrants

Description Of Business [Line Items]

Temporary equity shares outstanding

0

Convertible Preferred Stock

Description Of Business [Line Items]

Temporary equity shares outstanding

12,503,009

2,617,386

2,617,386

2,617,386

2,617,386

IPO

Description Of Business [Line Items]

Number of shares issued and sold

12,000,000

Public offering price per share | $ / shares

$ 17

Net proceeds from public offering | $

$ 186,400

IPO | Convertible Preferred Stock

Description Of Business [Line Items]

Common shares issued on conversion of convertible preferred stock

12,503,009

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)Segment	Jul. 01, 2020USD ($)
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of operating segments | Segment	1
Lease, practical expedient, use of hindsight	true
Operating lease right-of-use asset	$ 959
Operating lease liabilities	$ 972
ASU 2016-02
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Operating lease right-of-use asset		$ 1,000
Operating lease liabilities		$ 1,000
ASU 2018-07
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, material impact	true
ASU 2018-13
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, material impact	true

Fair Value - Schedule of Fair V

Fair Value - Schedule of Fair Value of Cash Equivalents, Short-term Investments and Long-term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	$ 165,725	$ 2,056
Recurring Basis | Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	152,822
Cash equivalents, Unrealized Losses	(3)
Cash equivalents, Fair Value	152,819
Recurring Basis | Cash Equivalents | Money Market Fund | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	66,596
Cash equivalents, Fair Value	66,596
Recurring Basis | Cash Equivalents | Commercial Paper | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	70,392
Cash equivalents, Unrealized Losses	(3)
Cash equivalents, Fair Value	70,389
Recurring Basis | Cash Equivalents | U.S. Government Debt and Agency Securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	835
Cash equivalents, Fair Value	835
Recurring Basis | Cash Equivalents | U.S. Treasury Bills | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	14,999
Cash equivalents, Fair Value	14,999
Recurring Basis | Short-term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	60,539
Investments, Unrealized Gains	9
Investments, Unrealized Losses	(1)
Investments, Fair Value	60,547
Recurring Basis | Short-term Investments | Commercial Paper | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	30,393
Investments, Unrealized Gains	2
Investments, Unrealized Losses	(1)
Investments, Fair Value	30,394
Recurring Basis | Short-term Investments | U.S. Government Debt and Agency Securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	29,220
Investments, Unrealized Gains	7
Investments, Fair Value	29,227
Recurring Basis | Short-term Investments | Corporate Bonds | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	926
Investments, Fair Value	926
Recurring Basis | Long-term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	33,654
Investments, Unrealized Gains	11
Investments, Unrealized Losses	(9)
Investments, Fair Value	33,656
Recurring Basis | Long-term Investments | U.S. Government Debt and Agency Securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	32,634
Investments, Unrealized Gains	11
Investments, Unrealized Losses	(9)
Investments, Fair Value	32,636
Recurring Basis | Long-term Investments | U.S. Treasury Bills | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	1,020
Investments, Fair Value	$ 1,020

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019	Sep. 22, 2020	Dec. 31, 2018
IPO
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Public offering price per share				$ 17
Grant Liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Additional grant liability	$ 464,000	$ 464,000	$ 100,000
Total grant liability	$ 1,500,000	$ 1,500,000	$ 1,036,000		$ 936,000

Fair Value - Schedule of Fair_2

Fair Value - Schedule of Fair Value Liabilities, Activity for Grant Liability (Details) - Grant Liability - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value at beginning of period		$ 1,036,000	$ 936,000
Change in fair value of liability	$ 464,000	464,000	100,000
Fair value at end of period	$ 1,500,000	$ 1,500,000	$ 1,036,000

Fair Value - Schedule of Fair_3

Fair Value - Schedule of Fair Value Liabilities, Activity for Derivative Liability (Details) - Derivative Liability - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value at beginning of period	$ 999	$ 539
Derivative liability recorded upon issuance of convertible notes	774	389
Change in fair value of liability	132	71
Settlement	$ (1,905)
Fair value at end of period		$ 999

Fair Value - Schedule of Fair_4

Fair Value - Schedule of Fair Value Liabilities, Activity for Convertible Preferred Stock Warrant Liability (Details) - Convertible Preferred Stock Warrant Liability $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Recognition of convertible preferred stock warrant liability	$ 364
Change in fair value of liability	641
Settlement	$ (1,005)

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Research and development expenses	$ 1,672	$ 536
Employee compensation and benefits	229	230
Professional services and other	224	86
Total accrued expenses	$ 2,125	$ 852

Other Income (Expense), Net - S

Other Income (Expense), Net - Schedule of Other Income (Expense), Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Income And Expenses [Abstract]
Part the Cloud research grant		$ 189	$ 22	$ 472
Interest and other income	$ 35	12	45	44
Interest expense		(98)	(366)	(236)
Change in fair value of derivative liability		(77)	(132)	(84)
Change in fair value of grant liability	(453)	(21)	(464)	(51)
Change in convertible preferred stock warrant liability	(641)		(641)
Gain on extinguishment of convertible notes			199
Total other income (expense), net	$ (1,059)	$ 5	$ (1,337)	$ 145

Significant Agreements - Additi

Significant Agreements - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of grant liability	$ 453,000	$ 21,000	$ 464,000	$ 51,000
Washington State University License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments payable upon marketing approval					$ 600,000
Annual minimum royalty payments					25,000
Net sales exempt from royalty payment					100,000
Royalty obligation	0		0
Washington State University License Agreement | Phase 2 Clinical Trial Initiation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments on development milestone achieved			50,000
Washington State University License Agreement | Phase 3 Clinical Trial Initiation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments, amount payable					300,000
Washington Life Services Discovery Fund Grant Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grant received					500,000	$ 250,000
Grant liability payable amount, maximum					$ 1,500,000
Estimated fair value of the grant liability	1,500,000		1,500,000				$ 1,000,000
Washington Life Services Discovery Fund Grant Agreement | Other Income (Expense), Net
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of grant liability	$ 453,000	$ 21,000	$ 464,000	$ 51,000

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	1 Months Ended		9 Months Ended
	May 31, 2020	Apr. 30, 2020	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Gain on extinguishment of debt			$ 199,000
Paycheck Protection Program
Debt Instrument [Line Items]
Debt instrument, interest rate		1.00%
Loan amount received		$ 215,000
Loan repayment term		2 years
Unsecured Convertible Notes
Debt Instrument [Line Items]
Debt instrument, principal amount			$ 1,700,000	$ 884,000	$ 1,300,000
Debt instrument, interest rate			5.00%
Debt instrument, maturity month and year			2021-12
Debt instrument, payment terms			No principal or interest is payable prior to maturity as the convertible notes and any accrued interest will automatically convert upon a qualified financing event at a conversion price equal to 85% of the price per share of the qualified financing.
Debt instrument, conversion price, percentage			85.00%
Debt instrument, repurchase price, percentage			200.00%
Debt conversion, converted instrument, amount	$ 3,800,000
Debt instrument, accrued interest	160,000
Gain on extinguishment of debt	$ 199,000
Unsecured Convertible Notes | Series B-1 Convertible Preferred Stock
Debt Instrument [Line Items]
Debt conversion, converted instrument, shares issued	512,858

Leases - Additional Information

Leases - Additional Information (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2020USD ($)
Lessee Lease Description [Line Items]
Operating lease expense	$ 34,000	$ 34,000
Variable lease expense	0	0
Short term leases, rent expense	$ 18,000	57,000
Cash paid for amounts included in measurement of lease liability		$ 21,000
Laboratory and Office Facilities | Bothell, Washington
Lessee Lease Description [Line Items]
Operating lease expiration month and year		2027-08
Operating lease initial term	7 years	7 years
Operating lease existence of option to extend		true
Operating lease, additional term of contract	5 years	5 years
Operating lease, remaining lease term	6 years 10 months 24 days	6 years 10 months 24 days
Incremental borrowing rate	8.20%	8.20%
Laboratory and Office Facilities | University of Washington, Seattle
Lessee Lease Description [Line Items]
Operating lease initial term	12 months	12 months

Leases - Reconciliation of Undi

Leases - Reconciliation of Undiscounted Operating Lease Cash Flows to Operating Lease Liability Payments (Details) $ in Thousands	Sep. 30, 2020USD ($)
Leases [Abstract]
2021	$ 234
2022	261
2023	269
2024	277
2025 and thereafter	779
Total undiscounted lease payments	1,820
Present value adjustment for minimum lease commitments	(457)
Tenant improvement allowance receivable	(391)
Net lease liability	$ 972

Convertible Preferred Stock - S

Convertible Preferred Stock - Schedule of Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Convertible Preferred Stock, Shares Authorized	0	2,797,464
Convertible Preferred Stock, Shares Issued	0	2,617,386
Convertible Preferred Stock, Shares Outstanding	0	2,617,386
Convertible Preferred Stock, Carrying Value		$ 17,051
Convertible Preferred Stock, Aggregate Liquidation Preference		$ 16,288
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible Preferred Stock, Shares Authorized		1,714,963
Convertible Preferred Stock, Shares Issued		1,534,885
Convertible Preferred Stock, Shares Outstanding		1,534,885
Convertible Preferred Stock, Carrying Value		$ 15,163
Convertible Preferred Stock, Aggregate Liquidation Preference		$ 15,215
Series A-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible Preferred Stock, Shares Authorized		1,082,501
Convertible Preferred Stock, Shares Issued		1,082,501
Convertible Preferred Stock, Shares Outstanding		1,082,501
Convertible Preferred Stock, Carrying Value		$ 1,888
Convertible Preferred Stock, Aggregate Liquidation Preference		$ 1,073

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - USD ($)	2 Months Ended	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Shares issued		0	2,617,386
Convertible preferred stock terms of conversion		The Series B convertible preferred stock financing triggered the automatic conversion of the Company’s outstanding convertible promissory notes into 512,858 shares of Series B-1 convertible preferred stock based on a price of $7.752 per share (85% of the $9.12 original issuance price of the Series B convertible preferred stock).
Common Stock | IPO
Class Of Stock [Line Items]
Convertible preferred stock shares issued upon conversion		12,503,009
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Shares issued	9,372,765
Purchase price per share	$ 9.12
Proceeds from issuance of convertible preferred stock	$ 81,600,000
Warrants to purchase preferred stock	2,343,168
Warrants to purchase preferred stock exercised	688,067
Convertible preferred stock issuance for net proceeds	$ 55,000
Series B Convertible Preferred Stock | Purchase Price $1.15 Per Share
Class Of Stock [Line Items]
Warrants to purchase preferred stock	127,481
Class of warrant or right, exercise price	$ 9.12
Series B-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Class of warrant or right, exercise price	$ 9.12
Convertible preferred stock shares issued upon conversion	512,858
Convertible preferred stock conversion price	$ 7.752
Convertible preferred stock conversion price percentage	85.00%

Common Stock - Schedule of Rese

Common Stock - Schedule of Reserved Shares of Common Stock for Future Issuance (Details) - shares	Sep. 30, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	6,040,707	4,535,203
Convertible Preferred Stock
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance		2,617,386
Stock Options Outstanding
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	1,927,428	1,514,770
Shares available for Future Grant under 2020 Equity Incentive Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	3,790,279	399,737
Shares available for Future Grant under Employee Stock Purchase Plan
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	323,000
Common Stock Warrants
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance		3,310

Stock-based Compensation - Stoc

Stock-based Compensation - Stock-based Compensation Expense Recognized (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]
Stock-based compensation expense	$ 111	$ 69	$ 218	$ 189
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	43	13	62	42
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 68	$ 56	$ 156	$ 147

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0.00%
Fair value of options vested	$ 219,000	$ 123,000
Aggregate intrinsic value of options exercised	9,400,000	4,000
Unrecognized compensation cost	$ 2,900,000
Remaining weighted-average period expected to recognize unrecognized compensation cost	1 year 11 months 12 days
Restricted Stock Award (RSA)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years
Employees and Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant-date fair value of options granted	$ 2,100,000	259,000
Fair value of options vested	144,000	64,000
Advisors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant-date fair value of options granted	727,000	46,000
Fair value of options vested	$ 75,000	$ 59,000
Non-employees | Restricted Stock Award (RSA)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares subject to repurchase upon discontinued service	4,204		8,407

Stock-based Compensation - Weig

Stock-based Compensation - Weighted-Average Assumptions used in Estimating Fair Value of each Stock Options using Black-Scholes Option-Pricing Model (Details)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.49%	1.58%
Expected volatility	80.11%	74.59%
Expected term (in years)	6 years 11 months 4 days	6 years 7 months 2 days
Expected dividend yield	0.00%

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Available for Grant, Beginning Balance	399,737
Available for Grant, Authorized	4,343,534
Available for Grant, Granted	(994,293)
Available for Grant, Forfeited/expired	41,301
Available for Grant, Ending Balance	3,790,279	399,737
Shares, Beginning Balance	1,514,770
Shares, Granted	994,293
Shares, Exercised	(540,334)
Shares, Forfeited/expired	(41,301)
Shares, Ending Balance	1,927,428	1,514,770
Shares, Expected to vest	1,298,059
Shares, Options exercisable	629,373
Weighted-Average Exercise price per Share, Beginning Balance | $ / shares	$ 1.03
Weighted-Average Exercise price per Share, Granted | $ / shares	16.20
Weighted-Average Exercise price per Share, Exercised | $ / shares	1
Weighted-Average Exercise price per Share, Forfeited/expired | $ / shares	1.35
Weighted-Average Exercise price per Share, Ending Balance | $ / shares	8.85	$ 1.03
Weighted-Average Exercise price per Share, Expected to vest | $ / shares	12.71
Weighted-Average Exercise price per Share, Options exercisable | $ / shares	$ 0.89
Weighted-Average Remaining Contractual Term (in years)	8 years 2 months 4 days	7 years 1 month 28 days
Weighted-Average Remaining Contractual Term, Expected to vest (in years)	9 years 6 months 7 days
Weighted-Average Remaining Contractual Term, Options exercisable (in years)	5 years 5 months 4 days
Aggregate Intrinsic Value, Beginning Balance | $	$ 18,521	$ 500
Aggregate Intrinsic Value, Expected to vest | $	7,460
Aggregate Intrinsic Value, Options exercisable | $	$ 11,061

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Stock Options Outstanding and Exercisable (Details) - $ / shares	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	1,927,428	1,514,770
Shares Exercisable	629,373
Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	1,498,690
Shares Exercisable	449,681
Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	428,738
Shares Exercisable	179,692
Exercise Price $0.16
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 0.16
Exercise Price $0.16 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	75,660
Shares Exercisable	75,660
Exercise Price $0.16 | Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	12,611
Shares Exercisable	12,611
Exercise Price $0.48
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 0.48
Exercise Price $0.48 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	162,353
Shares Exercisable	162,353
Exercise Price $1.00
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1
Exercise Price $1.00 | Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	37,830
Shares Exercisable	37,830
Exercise Price $1.04
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1.04
Exercise Price $1.04 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	70,933
Shares Exercisable	70,933
Exercise Price $1.04 | Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	31,525
Shares Exercisable	31,525
Exercise Price $1.19
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1.19
Exercise Price $1.19 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	52,645
Shares Exercisable	38,878
Exercise Price $1.19 | Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	34,677
Shares Exercisable	34,677
Exercise Price $1.31
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1.31
Exercise Price $1.31 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	63,050
Shares Exercisable	63,050
Exercise Price $1.35
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1.35
Exercise Price $1.35 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	294,754
Shares Exercisable	27,529
Exercise Price $1.35 | Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	116,642
Shares Exercisable	63,049
Exercise Price $1.49
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1.49
Exercise Price $1.49 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	31,525
Shares Exercisable	10,508
Exercise Price $17.00
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 17
Exercise Price $17.00 | Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	747,770
Shares Exercisable	770
Exercise Price $17.00 | Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	195,453

Stock-based Compensation - Su_3

Stock-based Compensation - Summary of RSA Activity (Details) - Restricted Stock Award (RSA)	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share Equivalent, Non-vested, Beginning Balance | shares	8,407
Share Equivalent, Vested | shares	(4,203)
Share Equivalent, Non-vested, Ending Balance | shares	4,204
Weighted-Average Grant Date Fair Value, Non-vested, Beginning Balance | $ / shares	$ 1.35
Weighted-Average Grant Date Fair Value, Non-vested, Vested | $ / shares	1.35
Weighted-Average Grant Date Fair Value, Non-vested, Ending Balance | $ / shares	$ 1.35

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Summary of Dilutive Securities excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	1,931,632	4,127,480
Convertible Preferred Stock on An as-converted Basis
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share		2,617,386
Unvested RSAs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	4,204	8,407
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share	1,927,428	1,498,377
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share		3,310

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 16, 2020	Sep. 30, 2020
Subsequent Event [Line Items]
Net proceeds from public offering		$ 187,224
Subsequent Event | Underwriters’ Option
Subsequent Event [Line Items]
Number of additional shares sold	1,397,712
Initial public offering price per share	$ 17
Net proceeds from public offering	$ 22,100