0001564590-21-015495 | 10-K | XBRL Viewer

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2020	Mar. 22, 2021	Sep. 22, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Entity Registrant Name	Athira Pharma, Inc.
Entity Central Index Key	0001620463
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3368487
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	ATHA
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity File Number	001-39503
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Address Address Line1	18706 North Creek Parkway
Entity Address Address Line2	Suite 104
Entity Address City Or Town	Bothell
Entity Address State Or Province	WA
Entity Address Postal Zip Code	98011
City Area Code	206
Local Phone Number	221-8115
Document Annual Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		37,120,363
Entity Public Float			$ 460.5
ICFR Auditor Attestation Flag	false

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 60,625	$ 2,056
Short-term investments	124,057
Unbilled grant receivable	1,300
Prepaid expenses and other current assets	6,355	97
Current portion of unsecured related party note receivable		7
Total current assets	192,337	2,160
Property and equipment, net	2,649
Operating lease right-of-use asset	936
Long-term investments	83,509
Other long-term assets	132
Unsecured related party note receivable		29
Total assets	279,563	2,189
Current liabilities:
Accounts payable	1,158	421
Accrued liabilities	3,123	852
Current operating lease liability	124
Total current liabilities	4,405	1,273
Operating lease liability, less current portion	876
Grant liability		1,036
Derivative liability		999
Convertible notes, net		1,553
Total liabilities	5,281	4,861
Commitments and contingencies (Note 9)
Convertible preferred stock, $0.0001 par value; 0 and 2,797,464 shares authorized at December 31, 2020 and 2019, respectively; 0 and 2,617,386 shares issued and outstanding at December 31, 2020 and 2019, respectively		17,051
Stockholders' equity (deficit):
Common stock, $0.0001 par value; 900,000,000 and 10,088,017 shares authorized at December 31, 2020 and 2019, respectively; 32,485,784 and 3,641,449 shares issued and outstanding at December 31, 2020 and 2019, respectively	3
Additional paid-in capital	315,288	1,364
Accumulated other comprehensive income	33
Accumulated deficit	(41,042)	(21,087)
Total stockholders' equity (deficit)	274,282	(19,723)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 279,563	$ 2,189

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 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	32,485,784	3,641,449
Common stock, shares outstanding	32,485,784	3,641,449

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 13,286	$ 3,793
General and administrative	6,709	1,656
Total operating expenses	19,995	5,449
Loss from operations	(19,995)	(5,449)
Grant income	1,321	754
Other income (expense), net	(1,281)	(466)
Net loss	(19,955)	(5,161)
Unrealized gain on available-for-sale securities	33
Comprehensive loss attributable to common stockholders	$ (19,922)	$ (5,161)
Net loss per share attributable to common stockholders, basic and diluted	$ (1.67)	$ (1.45)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	11,966,912	3,566,849

Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) Equity - 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	72			72
Issuance of common stock upon exercise of common stock options, shares			81,965
Stock-based compensation	253			253
Net loss	(5,161)					(5,161)
Ending balance at Dec. 31, 2019	$ (19,723)			1,364		(21,087)
Temporary equity, ending balance, shares at Dec. 31, 2019	2,617,386	2,617,386
Temporary equity, ending balance at Dec. 31, 2019	$ 17,051	$ 17,051
Ending balance, shares at Dec. 31, 2019			3,641,449
Issuance of common stock upon exercise of common stock options	$ 544			544
Issuance of common stock upon exercise of common stock options, shares	540,934		540,934
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	208,517		$ 2	208,515
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs, Shares			13,397,712
Conversion of convertible preferred stock	92,537		$ 1	92,536
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			2,402,680
Stock-based compensation	633			633
Other comprehensive income	33				$ 33
Net loss	(19,955)					(19,955)
Ending balance at Dec. 31, 2020	$ 274,282		$ 3	$ 315,288	$ 33	$ (41,042)
Temporary equity, ending balance, shares at Dec. 31, 2020	0
Ending balance, shares at Dec. 31, 2020			32,485,784

Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) Equity (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
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

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (19,955)	$ (5,161)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	633	253
Change in fair value of derivative liability	132	71
Change in fair value of convertible preferred stock warrant liability	641
Change in fair value of grant liability	464	100
Accretion of discounts on convertible notes	289	258
Non-cash interest expense	76	88
Gain on extinguishment of convertible notes	(199)
Amortization of premiums and accretion of discounts on available-for-sale securities, net	251
Changes in operating assets and liabilities:
Unbilled grant receivables, prepaid expenses and other current assets	(7,610)	(23)
Accounts payable and accrued expenses	2,601	701
Operating lease liability	64
Grant liability	(1,500)
Net cash (used in) operating activities	(24,113)	(3,713)
Investing activities
Purchases of available-for-sale securities	(226,837)	(995)
Maturities of available-for-sale securities	19,053	2,495
Purchases of property and equipment	(2,320)
Principal payments received on stockholder note receivable	36	6
Net cash (used in) provided by investing activities	(210,068)	1,506
Financing activities
Proceeds from exercise of common stock options and common stock warrants	643	72
Proceeds from initial public offering, net of issuance costs	208,517
Proceeds from sales of convertible preferred stock and stock warrants, net of issuance costs	81,926
Proceeds from issuance of convertible notes, including derivative, net of issuance costs	1,664	874
Net cash provided by financing activities	292,750	946
Net increase (decrease) in cash and cash equivalents	58,569	(1,261)
Cash and cash equivalents, beginning of period	2,056	3,317
Cash and cash equivalents, end of period	60,625	2,056
Supplemental disclosures of cash flow information:
Purchases of property and equipment included in accounts payable and accrued liabilities	331
Deferred offering costs included in accounts payable and accrued liabilities	77
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

Description of Business

12 Months Ended

Dec. 31, 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 consolidated financial statements and notes to the consolidated 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, the Company issued and sold 12,000,000 shares of common stock in the IPO at a public offering price of $17.00 per share, resulting in net proceeds of $186.4 million after deducting underwriting discounts and commissions and offering expenses paid by the Company. In October 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 and offering costs resulting in net proceeds to the Company of approximately $22.1 million.

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 the Company’s IPO, all outstanding common stock warrants were exercised into 1,085,334 shares of common stock. Additionally, all outstanding Series B convertible preferred stock warrants were remeasured to their fair value. The final remeasurement of the Series B convertible preferred stock warrant liability resulted in a $0.6 million loss which was recorded to other income (expense), net. Following remeasurement, all Series B convertible preferred stock warrants automatically net exercised into 59,093 shares of common stock and the corresponding liability was reclassified to additional paid in capital. Following the IPO, there are no shares of convertible preferred stock, common stock warrants, or Series B convertible preferred stock warrants outstanding.

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 December 31, 2020, it has raised aggregate net cash proceeds of $310.6 million primarily from the issuance of its common stock, convertible preferred stock, common stock warrants, and convertible notes. As of December 31, 2020, the Company had $268.2 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 $268.2 million of cash, cash equivalents, and investments at December 31, 2020 will be sufficient to fund its operating expenses and capital expenditure requirements through at least the 12 months following the date of the Company’s Annual Report on Form 10-K.

Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Significant Accounting Policies

2. Significant Accounting Policies

Basis of Presentation

The 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 since its creation, the Australian subsidiary’s financial position and results of operations are consolidated in the accompanying consolidated financial statements.

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. Actual results could differ from those estimates.

Cash and Cash Equivalents

The Company considers highly liquid investments with original maturities of three months or less to be cash equivalents.

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.

Concentration of Credit Risk

The Company is exposed to credit risk from its deposits of cash in excess of amounts insured by the Federal Deposit Insurance Corporation. The Company has not experienced any losses on its deposits of cash since inception.

Property and Equipment

Property and equipment consist of computer equipment, computer software, laboratory equipment, leasehold improvements and furniture and office equipment. Property and equipment are recorded at cost and depreciation is recognized using the straight-line method based on estimated useful life, generally three to five years. Leasehold improvements are amortized over the shorter of their useful life or the remaining lease term. Maintenance and repairs are charged to expense as incurred, and costs of improvements are capitalized.

The Company reviews long-lived assets for impairment whenever events or circumstances indicate the carrying amount of an asset group may not be recoverable. When such events occur, the Company determines whether there has been an impairment in value by comparing the asset’s carrying value with its fair value, as measured by the anticipated undiscounted net cash flows of the asset. If an impairment in value exists, the asset is written down to its estimated fair value. Gains and losses from asset disposals and impairment losses are classified within the consolidated statements of operations in accordance with the use of the asset. There were no impairment losses in the years ended December 31, 2020 and 2019 as there have been no events warranting an impairment analysis.

Fair Value Measurements

The carrying amounts of certain financial instruments, including cash, cash equivalents, 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 were accounted for as liabilities at fair value, because the shares underlying the warrants contained 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. Subsequent to the Company’s IPO, the corresponding liability was reclassified to additional paid in capital.

Grant Liability

The grant liability associated with the grants from the Washington LSDF was accounted for under Accounting Standards Codification (“ASC”) 825-10, Financial Instruments − Overall. The estimated fair value of the grant liability was reassessed at each balance sheet date, with changes in fair value reflected in other income (expense), net. The Company estimated the fair value of the grant liability by using a discounted cash flow simulation methodology that assigns probabilities to the timing and likelihood of each triggering event, a discount rate based on market data for securities with similar durations and credit ratings to the Company, and the expected payment amount. The assumptions used to calculate the fair value of the grant liability were subject to significant judgment. 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 and repaid in full as of December 31, 2020. See Note 7.

Derivative Liability, Convertible Notes Discount and Amortization

The Company’s convertible notes (see Note 8) had conversion and redemption features that met the definition of an embedded derivative and were therefore subject to derivative accounting. The initial fair value of the derivative was recorded as a discount to the convertible notes, with a corresponding derivative liability. The discount to the convertible notes was amortized using the effective interest method. The amortization of the discount is included in other income (expense), net in the statements of operations and comprehensive loss. The derivative liability related to these features is recorded at estimated fair value on a recurring basis. Any changes in fair value were reflected in other income (expense), net in the statements of operations and comprehensive loss at each period end while such instruments were outstanding. The derivative liability was settled in May 2020 upon conversion of the underlying convertible notes into Series B-1 convertible preferred stock. See Note 10.

Grant Income

In January 2019, the Alzheimer’s Association awarded the Company a $1.0 million Part the Cloud research grant. Grant proceeds must be used to advance the Company’s ATH-1017 product candidate in the Alzheimer’s disease setting. Reporting of expenses incurred supported by the grant as well as research updates are sent to the Alzheimer’s Association semi-annually. Under the terms of the agreement, the Company received $776,000 in 2019 and received the remaining $224,000 in March 2021 after having completed certain development milestones in October 2020. The Company recognizes income related to the Part the Cloud research grant as qualifying expenses under the grant agreement are incurred. During the years ended December 31, 2020 and 2019, the Company recognized $246,000 and $754,000, respectively, in grant income associated with the Part the Cloud research grant. As of December 31, 2020, the Company has incurred qualifying expenses in excess of cash received of approximately $224,000, which is included in unbilled grant receivable on the consolidated balance sheets. As of December 31, 2019, the Company had cash received in excess of qualifying expenses of approximately $22,000, a liability for which was included in accrued expenses on the consolidated balance sheets.

In December 2020, the Company accepted a grant from the National Institute on Aging (“NIA”) of the National Institutes of Health (“NIH”) to support its ACT-AD Phase 2 clinical trial for ATH-1017, the Company’s lead therapeutic candidate being developed for the treatment of individual with mild-to-moderate Alzheimer’s disease. Under the terms of the agreement, the Company may potentially receive $7.8 million with the potential for an additional $7.4 million, up to an aggregate of $15.2 million. The Company recognizes income related to the NIH grant as qualifying expenses under the grant agreement are incurred. During the year ended December 31, 2020, the Company had recognized $1.1 million in grant income associated with the NIH grant, which is included in grant income in the consolidated statement of operations and comprehensive loss. As of December 31, 2020, the Company has incurred qualifying expenses in excess of cash received of approximately $1.1 million, which is included in unbilled grant receivable on the consolidated balance sheets.

Research and Development Expenses

Research and development expenses consist primarily of direct and indirect costs incurred for research activities, including development of the 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 expensed 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.

General and Administrative Expenses

General and administrative expenses consist primarily of personnel-related costs, consisting of employee salaries, related benefits, and stock-based compensation expense for employees in the executive, legal, finance and accounting, human resources, and other administrative functions. General and administrative expenses also include third-party costs such as legal costs, insurance costs, accounting, auditing and tax related fees, consulting fees and facilities and other expenses not otherwise included as research and development expenses. General and administrative costs are expensed as incurred.

Leases

As discussed in Recently Adopted Accounting Standards below, the Company adopted Accounting Standards Codification (“ASC”) Topic 842 - Leases, on July 1, 2020, effective January 1, 2020. The Company determines if an arrangement contains a lease at inception. The Company performed an evaluation of contracts in accordance with ASC 842 and has determined it has an operating lease agreement for the laboratory and office facilities that the Company occupies. Operating lease right-of-use (“ROU”) assets and operating lease liabilities are recognized at the date the underlying asset becomes available for the Company’s use. Operating lease liabilities are based on the present value of the future minimum lease payments over the lease term. ROU assets are measured at the amount of the lease liability, adjusted for any initial direct costs incurred and any lease payments made at or before the lease commencement date, less lease incentives received. As the Company’s lease generally does not provide an implicit interest rate, the present value of the future minimum lease payments is determined using the Company’s incremental borrowing rate. This rate is an estimate of the collateralized borrowing rate the Company would incur on its future lease payments over a similar term and is based on the information available to the Company at the lease commencement date, discussed in more detail below.

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.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

In assessing the Company’s ability to realize deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences are deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future income, tax planning strategies in making this assessment.

The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company accrues interest and penalties related to unrecognized tax benefits in its provision for incomes taxes.

Comprehensive Loss

Comprehensive loss consists of net loss and other gains and losses affecting stockholders’ deficit that, under U.S. GAAP, are excluded from net loss. The Company’s comprehensive loss is comprised of net loss and unrealized gains and losses on available-for-sale investments.

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.

Foreign Currency Translation

Assets and liabilities denominated in foreign currencies were translated into U.S. dollars, the reporting currency, at the exchange rate prevailing at the balance sheet date. Income and expenses denominated in foreign currencies were translated into U.S. dollars at the average exchange rate for the period and the translation adjustments are reported within other income (expense), net in the consolidated statement of operations and comprehensive loss. The functional currency of the Company’s Australian subsidiary is the U.S. dollar.

Related Party Transactions

As of December 31, 2019, the Company had an unsecured note receivable outstanding from its chief executive officer of approximately $36,000. The note incurred interest at 1.45% and the remaining outstanding principal was repaid in full in August 2020. The note is included in current portion of unsecured related party note receivable and unsecured related party note receivable in the accompanying balance sheet as of December 31, 2019. Interest income is recognized using the effective interest method, and is included in other income (expense), net in the consolidated statements of operations and comprehensive loss.

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 consolidated 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), intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheets and disclosing key information about leasing arrangements. The Company adopted the guidance on July 1, 2020, effective January 1, 2020, using the optional transition method described in ASU 2018-11, Leases (Topic 842) Targeted Improvements. Prior to adoption, the Company did not have any leases with initial terms longer than 12 months. The Company will continue to account for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term.

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 consolidated balance sheets but did not have a material impact on its consolidated statements of operations or consolidated 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 9, Commitments and Contingencies, for additional information regarding leases.

In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718) Improvements to Nonemployee Share-Based Payment Accounting. The ASU simplified the accounting for share-based payments to non-employees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted the standard on January 1, 2020 and it did not have a material impact on its financial condition, results of operations and cash flows.

In August 2018, the FASB issued ASU 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates certain disclosure requirements for fair value measurements for all entities, requires public entities to disclose certain new information and modifies some disclosure requirements. The Company adopted this standard on January 1, 2020 and it did not have a material impact on its consolidated financial statements.

In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes. This update removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. Early adoption of the new standard is permitted for companies for periods for which financial statements have not yet been issued. The Company early adopted the standard effective January 1, 2020. Since the Company has incurred net losses since its inception and maintains a full valuation allowance on the net deferred tax assets, the adoption did not have a material impact on the financial condition, results of operations and cash flows, or financial statement disclosures.

Recent Accounting Pronouncements Not Yet Adopted

In June 2016, the FASB issued ASU 2016-13, Financial Instruments: Credit Losses (Topic 326) as clarified in ASU 2019-04, ASU 2019-05, and ASU 2020-02. The objective of the standard is to provide information about expected credit losses on financial instruments at each reporting date and to change how other-than-temporary impairments on investment securities are recorded. The ASU will become effective to the Company beginning on January 1, 2023, with early adoption permitted. The Company is currently evaluating the potential impacts of the ASU on its financial condition, results of operations, cash flows and financial statement disclosures.

Although there were several other new accounting pronouncements issued or proposed by the FASB, the Company does not believe any of these have had or will have material impact on its consolidated financial statements.

Fair Value

12 Months Ended

Dec. 31, 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 December 31, 2020 (in thousands):

	December 31, 2020
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	5		—		—		$	5
Commercial paper	2		44,318		—		(2	)		44,316
U.S. government debt and agency securities	2		4,999		—		—			4,999
U.S. treasury bills	2		4,450		—		—			4,450
Total cash equivalents		$	53,772	$	—	$	(2	)	$	53,770
Short-term investments:
Commercial paper	2		77,272		1		(4	)		77,269
U.S. government debt and agency securities	2		31,835		7		—			31,842
U.S. treasury bills	2		14,029		—		(3	)		14,026
Corporate bonds	2		920		—		—			920
Total short-term investments		$	124,056	$	8	$	(7	)	$	124,057
Long-term investments:
U.S. government debt and agency securities	2		78,924		32		—			78,956
U.S. treasury bills	2		4,551		2		—			4,553
Total long-term investments		$	83,475	$	34	$	—		$	83,509

All the commercial paper, U.S. government debt and agency securities, U.S. treasury bills, and corporate bonds designated as short-term investments have an effective maturity date that is equal to or less than one year from the respective balance sheet date. Those that are designated as long-term investments have an effective maturity date that is more than one year, but less than two years, from the respective balance sheet date.

As of December 31, 2019, the Company held level 1 cash equivalent financial assets with amortized costs and fair values of $894,000.

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 7), and the derivative was settled upon the Company’s conversion of its convertible notes in May 2020 (see Note 8). 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 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 years ended December 31, 2020 and 2019 (in thousands):

	Year Ended December 31, 2020			Year Ended December 31, 2019
Fair value at beginning of period	$	1,036		$	936
Change in fair value of grant liability		464			100
Grant liability settled upon completion of IPO		(1,500	)		—
Fair value at end of period	$	—		$	1,036

The following table presents the activity for the derivative liability for the years ended December 31, 2020 and 2019 (in thousands):

	Year Ended December 31, 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 for the year ended December 31, 2020 (in thousands):

	Year Ended December 31, 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.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Property and Equipment, Net

12 Months Ended

Dec. 31, 2020

Property Plant And Equipment [Abstract]

Property and Equipment, Net

4. Property and Equipment, Net

Property and equipment consisted of the following (in thousands):

	December 31, 2020			December 31, 2019
Laboratory equipment	$	81		$	69
Construction in progress		2,639			—
Property and equipment, as cost		2,720			69
Less: accumulated depreciation		(71	)		(69	)
Property and equipment, net	$	2,649		$	—

Depreciation expense was $2,000 and $2,000 for the years ended December 31, 2020 and 2019, respectively.

Accrued Expenses

12 Months Ended

Dec. 31, 2020

Payables And Accruals [Abstract]

Accrued Expenses

5. Accrued Expenses

Accrued expenses consisted of the following (in thousands):

	December 31, 2020		December 31, 2019
Employee compensation and benefits	$	1,624	$	230
Research and development expenses		1,169		536
Professional services and other		330		86
Total accrued expenses	$	3,123	$	852

Other Income (Expense), Net

12 Months Ended

Dec. 31, 2020

Other Income And Expenses [Abstract]

Other Income (Expense), Net

6. Other Income (Expense), Net

Other income (expense), net consisted of the following (in thousands):

	Year Ended December 31,
	2020			2019
Interest and other income		124			51
Interest expense		(367	)		(346	)
Change in fair value of derivative liability		(132	)		(71	)
Change in fair value of grant liability		(464	)		(100	)
Change in convertible preferred stock warrant liability		(641	)		—
Gain on extinguishment of convertible notes		199			—
Total other income (expense), net	$	(1,281	)	$	(466	)

Significant Agreements

12 Months Ended

Dec. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Significant Agreements

7. Significant Agreements

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 December 31, 2020.

During the year ended December 31, 2020, the Phase 2 clinical trial milestone had been reached and a payment of $50,000 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 December 31, 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 December 31, 2020, the Company has not entered into or incurred any liability from a sublicense agreement.

LSDF 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 is reassessed at each balance sheet date, with changes in fair value reflected in other income (expense), net. To determine the estimated fair value of the grant liability, the Company used a discounted cash flow simulation methodology that assigns probabilities to the timing and likelihood of each triggering event, a discount rate based on market data for securities with similar durations and credit ratings to the Company, and the expected payment amount. The assumptions used to calculate the fair value of the grant liability are subject to significant judgment, and payment may be in an amount different from the liability that the Company estimates. However, total payments under the agreements will not exceed $1.5 million.

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 prior to settlement. The changes in the fair value of the liability resulted in expense of approximately $464,000 and $100,000 for the years ended December 31, 2020 and 2019, respectively, which were included in other income (expense), net in the accompanying consolidated statements of operations and comprehensive loss.

Convertible Notes

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Convertible Notes

8. 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 $0.9 million and $1.3 million and in 2019 and 2018, respectively. The notes accrued 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. The fair value of the embedded derivative was determined using a discounted cash flow simulation methodology that assigns probabilities to the timing and likelihood of each event. The discount rate was determined based on market interest rate data for securities with similar durations and credit ratings to the convertible notes. The fair value of the embedded derivative was recorded as a liability with an offsetting amount recorded as a discount on the convertible notes at each issuance. The discount is being amortized to interest expense using the effective interest method over the contractual term of the notes.

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.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

9. Commitments and Contingencies

Legal Proceedings

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and that such expenditures can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount.

Indemnifications

In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company enters into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance coverage that reduces its exposure and enables the Company to recover a portion of any future amounts paid. The Company believes the estimated fair value of these indemnification agreements in excess of applicable insurance coverage is minimal.

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 December 31, 2020, the remaining lease term for the Company’s operating lease was 6.7 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 December 31, 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):

	December 31, 2020
2021		233
2022		261
2023		269
2024		277
2025		286
Thereafter		494
Total undiscounted lease payments		1,820
Present value adjustment for minimum lease commitments		(429	)
Tenant improvement allowance receivable		(391	)
Net lease liability	$	1,000

Operating lease expense was $85,000 for the year ended December 31, 2020. The Company did not incur variable lease expense for operating leases during the year ended December 31, 2020. Rent expense recognized for short-term leases was $76,000 and $97,000 for the years ended December 31, 2020 and 2019, respectively.

Cash paid for amounts included in the measurement of the lease liability for the year ended December 31, 2020 was $21,000.

Convertible Preferred Stock

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Convertible Preferred Stock

10. 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

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Common Stock

11. 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:

	December 31, 2020		December 31, 2019
Convertible preferred stock		—		2,617,386
Stock options outstanding		1,974,873		1,514,770
Shares available for future grant under the 2020 Equity Incentive Plan		3,742,234		399,737
Shares available for future grant under the Employee Stock Purchase Plan		323,000		—
Common stock warrants		—		3,310
Total		6,040,107		4,535,203

Stock-based Compensation

12 Months Ended

Dec. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-based Compensation

12. Stock-based Compensation

Stock‑based compensation expense recognized was as follows (in thousands):

	Year Ended December 31,
	2020		2019
Research and development	$	215	$	55
General and administrative		418		198
Total stock-based compensation expense	$	633	$	253

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:

	Year Ended December 31,
	2020			2019
Risk-free interest rate		0.49	%		1.60	%
Expected volatility		87.41	%		75.00	%
Expected term (in years)		6.87			6.50
Expected dividend yield		—			—

The weighted-average grant-date fair value of options granted to employees and directors during the years ended December 31, 2020 and 2019 were $3.4 million and $274,000 respectively. The weighted-average grant-date fair value of options granted to advisors during the year ended December 31, 2020 was $818,000. The remeasured weighted-average fair value of options granted to advisors during the year ended December 31, 2019 was $47,000.

Stock Option Activity

A summary of option activity for the year ended December 31, 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		(1,053,053	)		1,053,053			16.72
Exercised		—			(540,934	)		1.00
Forfeited/expired		52,016			(52,016	)		4.57
Balance at December 31, 2020		3,742,234			1,974,873		$	9.31		7.98	$	49,275
Expected to vest					1,315,050		$	13.67		9.31	$	27,398
Options exercisable					659,823		$	1.12		5.34	$	21,877

The total fair value of options granted to employees, directors, and advisors that vested during the year ended December 31, 2020 was $271,000 which included $191,000 for options granted to employees and directors and $80,000 for options granted to advisors. The total fair value of options that vested during the year ended December 31, 2019 was $183,000, which included $104,000 for options granted to employees and directors and $79,000 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 December 31, 2020. The aggregate intrinsic value of options exercised was $18.0 million and $39,000 during the year ended December 31, 2020 and 2019, respectively, determined as of the date of option exercise. As of December 31, 2020, there was $3.9 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 1.75 years. The Company utilizes newly issued shares to satisfy option exercises.

Stock options outstanding and exercisable consisted of the following at December 31, 2020:

	Employees and Directors				Non-employees
Exercise Price ($)	Shares Outstanding		Shares Exercisable		Shares Outstanding		Shares Exercisable
0.16		75,660		75,660		12,610		12,610
0.48		162,353		162,353		—		—
1.00		—		—		37,830		37,830
1.04		70,931		70,931		31,525		31,525
1.19		52,045		46,685		34,677		34,677
1.31		63,050		63,050		—		—
1.35		294,760		40,139		116,642		63,837
1.49		31,525		10,508		—		—
17.00		737,052		10,015		195,453		—
22.22		29,618		—		—		—
23.79		1,400		—		—		—
29.41		27,742		—		—		—
Total		1,546,136		479,341		428,737		180,479

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 December 31, 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 year ended December 31, 2020 was as follows:

	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 December 31, 2020		4,204		$	1.35

Employee Stock Purchase Plan

In August 2020, the Company’s board of directors adopted the 2020 Employee Stock Purchase Plan (“ESPP”) which became effective in September 2020. Under the ESPP, eligible employees can authorize payroll deductions for amounts up to the lesser of 15% of their qualifying wages or the statutory limit under the U.S. Internal Revenue Code. The ESPP provides for offering periods of six months in duration with one purchase period per offering period beginning May 18 and November 18 of each year. The first ESPP offering period commenced in September 2020 upon the Company’s Registration Statement becoming effective and will end May 18, 2021. Participants in an offering period will be granted the right to purchase common shares at a price per share that is 85% of the lesser of the fair market value of the shares at (i) the first day of the offering period or (ii) the end of each purchase period within the offering period. A maximum of 5,000 shares of common stock may be purchased by each participant at the purchase date during the offering period. The fair value of the ESPP options granted is determined using the Black-Scholes model and is amortized on a straight-line basis. The number of shares reserved for the ESPP automatically increases each year, beginning on January 1, 2021 by the lesser of (i) 646,000 shares of common stock, (ii) 1% of the outstanding shares of common stock on the last day of the immediately preceding fiscal year, or (iii) such number of shares determined by the board no later than the last day of the immediately preceding fiscal year. As of December 31, 2020, 323,000 shares of common stock were reserved for future grants under the ESPP. On January 1, 2021, and additional 324,851 shares of common stock became available for future grants under the ESPP. Stock-based compensation expense recognized during the year ended December 31, 2020 associated with the ESPP was not material.

Income Taxes

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Taxes

13. Income Taxes

Components of Income and Income Tax

The Company did not record a provision (benefit) for income taxes for the years ended December 31, 2020 and 2019. Net loss is attributable to the following tax jurisdictions (in thousands):

	Year Ended December 31,
	2020			2019
United States	$	(19,969	)	$	(5,161	)
Foreign		14			—
Net Loss	$	(19,955	)	$	(5,161	)

The provision for income taxes differs from the amount expected by applying the federal statutory rates to the net loss before taxes as follows:

	Year Ended December 31,
	2020			2019
Federal statutory income tax rate		21.0	%		21.0	%
Non-deductible expenses and others		0.2			(0.6	)
Non-deductible expense related to the convertible notes and derivative liability		(1.0	)		(1.7	)
Non-deductible expense related to the grant liability		(0.1	)		(0.3	)
Tax credits		1.5			2.2
Change in valuation allowance		(21.6	)		(20.6	)
Effective income tax rate		—	%		—	%

Deferred Tax Assets and Liabilities

The components of the Company’s deferred tax assets and liabilities were as follows (in thousands):

	Year Ended December 31,
	2020			2019
Deferred tax assets:
Net operating loss carryforwards	$	8,090		$	3,911
Research and development tax credit carryforwards		1,011			716
Accrued liabilities		295			90
Stock-based compensation		106			82
Operating lease liability		210			—
Other		72			3
Total deferred tax assets		9,784			4,802
Deferred tax liabilities:
Right of use asset		(197	)		—
Prepaid expenses and other		(489	)		(12	)
Total deferred tax liabilities		(686	)		(12	)
Less valuation allowance		(9,098	)		(4,790	)
Net deferred tax assets	$	—		$	—

Deferred income taxes reflect temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes, and operating losses and tax credit carryforwards. The Company considers a number of factors concerning the realizability of its net deferred tax assets, including its history of operating losses, the nature of the deferred tax assets, and the timing, likelihood and amount, if any, of future taxable income during the periods in which those temporary differences and carryforwards become deductible, all of which require significant judgment. As of December 31, 2020, the Company has recorded a full valuation allowance on its net deferred tax assets as the Company has concluded that it is not more likely than not that such losses or credits will be utilized. The valuation allowance increased by $4.3 million and $1.1 million during 2020 and 2019, respectively.

At December 31, 2020, the Company has federal net operating loss and tax credit carryforwards of $9.4 million and $1.3 million, respectively, which expire over a period of 11 to 17 years. Net operating loss carryforwards of $29.1 million were generated after 2017, and therefore do not expire.

Uncertain Tax Positions

The Company files federal income tax returns. With few exceptions, the Company is no longer subject to income tax examinations by tax authorities for years prior to 2016. However, to the extent allowed by law, the tax authorities may have the right to examine prior periods where net operating losses or tax credits were generated and carried forward and may make adjustments to the amount of the net operating loss or credit carryforward amount. The Company is not currently under examination in any jurisdiction.

A reconciliation of the beginning and ending amount of unrecognized tax benefits for uncertain tax positions were as follows (in thousands):

	Year Ended December 31,
	2020		2019
Beginning balance	$	239	$	200
Additions for tax positions taken in the current year		98		39
Ending balance	$	337	$	239

If the unrecognized tax benefits for uncertain tax positions as of December 31, 2020 are recognized, there will be no impact to the effective tax rate due to the valuation allowance. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax expense line in the accompanying consolidated financial statements. At December 31, 2020, there were no material interest and penalties on uncertain tax benefits. The Company does not anticipate any significant changes to its unrecognized tax benefits in the next 12 months.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Employee Benefit Plans

12 Months Ended

Dec. 31, 2020

Employee Benefit Plans [Abstract]

Employee Benefit Plans

14. Employee Benefit Plans

The Company has a 401(k) Plan for all of its employees. The 401(k) Plan allows eligible employees to defer, at the employee’s discretion, up to 100% of their pretax compensation up to the Internal Revenue Service annual limit. The Company did not make any matching contributions for the years ended December 31, 2020 or 2019.

Net Loss Per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Net Loss Per Share Attributable to Common Stockholders

15. 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:

	Year Ended December 31,
	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		1,974,873		1,514,770
Employee stock purchase plan		3,995		—
Common stock warrants		—		3,310
Total		1,983,072		4,143,873

Subsequent Events

12 Months Ended

Dec. 31, 2020

Subsequent Events [Abstract]

Subsequent Events

16. Subsequent Events

On January 20, 2021, the Company’s registration statement on Form S-1 (File No. 333-252192) for its follow-on public offering of common stock was declared effective by the Securities and Exchange Commission. On January 25, 2021, the Company issued and sold 4,000,000 shares of common stock in the follow-on public offering at a public offering price of $22.50 per share, resulting in net proceeds of $84.1 million after deducting underwriting discounts and commissions and offering expenses paid by the Company.

In February 2021, the Company sold an additional 600,000 shares of common stock to the underwriters of the follow-on public offering upon full exercise of the underwriters’ option to purchase additional shares at the follow-on public offering price of $22.50 per share, less underwriting discounts and commissions and offering costs resulting in net proceeds to use of approximately $12.7 million.

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The 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 since its creation, the Australian subsidiary’s financial position and results of operations are consolidated in the accompanying consolidated financial statements.
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. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers highly liquid investments with original maturities of three months or less to be cash equivalents.
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.
Concentration of Credit Risk	Concentration of Credit Risk The Company is exposed to credit risk from its deposits of cash in excess of amounts insured by the Federal Deposit Insurance Corporation. The Company has not experienced any losses on its deposits of cash since inception.
Property and Equipment	Property and Equipment Property and equipment consist of computer equipment, computer software, laboratory equipment, leasehold improvements and furniture and office equipment. Property and equipment are recorded at cost and depreciation is recognized using the straight-line method based on estimated useful life, generally three to five years. Leasehold improvements are amortized over the shorter of their useful life or the remaining lease term. Maintenance and repairs are charged to expense as incurred, and costs of improvements are capitalized. The Company reviews long-lived assets for impairment whenever events or circumstances indicate the carrying amount of an asset group may not be recoverable. When such events occur, the Company determines whether there has been an impairment in value by comparing the asset’s carrying value with its fair value, as measured by the anticipated undiscounted net cash flows of the asset. If an impairment in value exists, the asset is written down to its estimated fair value. Gains and losses from asset disposals and impairment losses are classified within the consolidated statements of operations in accordance with the use of the asset. There were no impairment losses in the years ended December 31, 2020 and 2019 as there have been no events warranting an impairment analysis.
Fair Value Measurements	Fair Value Measurements The carrying amounts of certain financial instruments, including cash, cash equivalents, 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 were accounted for as liabilities at fair value, because the shares underlying the warrants contained 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. Subsequent to the Company’s IPO, the corresponding liability was reclassified to additional paid in capital.
Grant Liability	Grant Liability The grant liability associated with the grants from the Washington LSDF was accounted for under Accounting Standards Codification (“ASC”) 825-10, Financial Instruments − Overall. The estimated fair value of the grant liability was reassessed at each balance sheet date, with changes in fair value reflected in other income (expense), net. The Company estimated the fair value of the grant liability by using a discounted cash flow simulation methodology that assigns probabilities to the timing and likelihood of each triggering event, a discount rate based on market data for securities with similar durations and credit ratings to the Company, and the expected payment amount. The assumptions used to calculate the fair value of the grant liability were subject to significant judgment. 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 and repaid in full as of December 31, 2020. See Note 7.
Derivative Liability Convertible Notes Discount and Amortization	Derivative Liability, Convertible Notes Discount and Amortization The Company’s convertible notes (see Note 8) had conversion and redemption features that met the definition of an embedded derivative and were therefore subject to derivative accounting. The initial fair value of the derivative was recorded as a discount to the convertible notes, with a corresponding derivative liability. The discount to the convertible notes was amortized using the effective interest method. The amortization of the discount is included in other income (expense), net in the statements of operations and comprehensive loss. The derivative liability related to these features is recorded at estimated fair value on a recurring basis. Any changes in fair value were reflected in other income (expense), net in the statements of operations and comprehensive loss at each period end while such instruments were outstanding. The derivative liability was settled in May 2020 upon conversion of the underlying convertible notes into Series B-1 convertible preferred stock. See Note 10.
Grant Income	Grant Income In January 2019, the Alzheimer’s Association awarded the Company a $1.0 million Part the Cloud research grant. Grant proceeds must be used to advance the Company’s ATH-1017 product candidate in the Alzheimer’s disease setting. Reporting of expenses incurred supported by the grant as well as research updates are sent to the Alzheimer’s Association semi-annually. Under the terms of the agreement, the Company received $776,000 in 2019 and received the remaining $224,000 in March 2021 after having completed certain development milestones in October 2020. The Company recognizes income related to the Part the Cloud research grant as qualifying expenses under the grant agreement are incurred. During the years ended December 31, 2020 and 2019, the Company recognized $246,000 and $754,000, respectively, in grant income associated with the Part the Cloud research grant. As of December 31, 2020, the Company has incurred qualifying expenses in excess of cash received of approximately $224,000, which is included in unbilled grant receivable on the consolidated balance sheets. As of December 31, 2019, the Company had cash received in excess of qualifying expenses of approximately $22,000, a liability for which was included in accrued expenses on the consolidated balance sheets. In December 2020, the Company accepted a grant from the National Institute on Aging (“NIA”) of the National Institutes of Health (“NIH”) to support its ACT-AD Phase 2 clinical trial for ATH-1017, the Company’s lead therapeutic candidate being developed for the treatment of individual with mild-to-moderate Alzheimer’s disease. Under the terms of the agreement, the Company may potentially receive $7.8 million with the potential for an additional $7.4 million, up to an aggregate of $15.2 million. The Company recognizes income related to the NIH grant as qualifying expenses under the grant agreement are incurred. During the year ended December 31, 2020, the Company had recognized $1.1 million in grant income associated with the NIH grant, which is included in grant income in the consolidated statement of operations and comprehensive loss. As of December 31, 2020, the Company has incurred qualifying expenses in excess of cash received of approximately $1.1 million, which is included in unbilled grant receivable on the consolidated balance sheets.
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 the 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 expensed 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.
General and Administrative Expenses	General and Administrative Expenses General and administrative expenses consist primarily of personnel-related costs, consisting of employee salaries, related benefits, and stock-based compensation expense for employees in the executive, legal, finance and accounting, human resources, and other administrative functions. General and administrative expenses also include third-party costs such as legal costs, insurance costs, accounting, auditing and tax related fees, consulting fees and facilities and other expenses not otherwise included as research and development expenses. General and administrative costs are expensed as incurred.
Leases	Leases As discussed in Recently Adopted Accounting Standards below, the Company adopted Accounting Standards Codification (“ASC”) Topic 842 - Leases, on July 1, 2020, effective January 1, 2020. The Company determines if an arrangement contains a lease at inception. The Company performed an evaluation of contracts in accordance with ASC 842 and has determined it has an operating lease agreement for the laboratory and office facilities that the Company occupies. Operating lease right-of-use (“ROU”) assets and operating lease liabilities are recognized at the date the underlying asset becomes available for the Company’s use. Operating lease liabilities are based on the present value of the future minimum lease payments over the lease term. ROU assets are measured at the amount of the lease liability, adjusted for any initial direct costs incurred and any lease payments made at or before the lease commencement date, less lease incentives received. As the Company’s lease generally does not provide an implicit interest rate, the present value of the future minimum lease payments is determined using the Company’s incremental borrowing rate. This rate is an estimate of the collateralized borrowing rate the Company would incur on its future lease payments over a similar term and is based on the information available to the Company at the lease commencement date, discussed in more detail below. 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.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. In assessing the Company’s ability to realize deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences are deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future income, tax planning strategies in making this assessment. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company accrues interest and penalties related to unrecognized tax benefits in its provision for incomes taxes.
Comprehensive Loss	Comprehensive Loss Comprehensive loss consists of net loss and other gains and losses affecting stockholders’ deficit that, under U.S. GAAP, are excluded from net loss. The Company’s comprehensive loss is comprised of net loss and unrealized gains and losses on available-for-sale investments.
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.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities denominated in foreign currencies were translated into U.S. dollars, the reporting currency, at the exchange rate prevailing at the balance sheet date. Income and expenses denominated in foreign currencies were translated into U.S. dollars at the average exchange rate for the period and the translation adjustments are reported within other income (expense), net in the consolidated statement of operations and comprehensive loss. The functional currency of the Company’s Australian subsidiary is the U.S. dollar.
Related Party Transactions	Related Party Transactions As of December 31, 2019, the Company had an unsecured note receivable outstanding from its chief executive officer of approximately $36,000. The note incurred interest at 1.45% and the remaining outstanding principal was repaid in full in August 2020. The note is included in current portion of unsecured related party note receivable and unsecured related party note receivable in the accompanying balance sheet as of December 31, 2019. Interest income is recognized using the effective interest method, and is included in other income (expense), net in the consolidated statements of operations and comprehensive loss.
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 consolidated 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), intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheets and disclosing key information about leasing arrangements. The Company adopted the guidance on July 1, 2020, effective January 1, 2020, using the optional transition method described in ASU 2018-11, Leases (Topic 842) Targeted Improvements. Prior to adoption, the Company did not have any leases with initial terms longer than 12 months. The Company will continue to account for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term. 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 consolidated balance sheets but did not have a material impact on its consolidated statements of operations or consolidated 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 9, Commitments and Contingencies, for additional information regarding leases. In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718) Improvements to Nonemployee Share-Based Payment Accounting. The ASU simplified the accounting for share-based payments to non-employees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted the standard on January 1, 2020 and it did not have a material impact on its financial condition, results of operations and cash flows. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates certain disclosure requirements for fair value measurements for all entities, requires public entities to disclose certain new information and modifies some disclosure requirements. The Company adopted this standard on January 1, 2020 and it did not have a material impact on its consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes. This update removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. Early adoption of the new standard is permitted for companies for periods for which financial statements have not yet been issued. The Company early adopted the standard effective January 1, 2020. Since the Company has incurred net losses since its inception and maintains a full valuation allowance on the net deferred tax assets, the adoption did not have a material impact on the financial condition, results of operations and cash flows, or financial statement disclosures. Recent Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments: Credit Losses (Topic 326) as clarified in ASU 2019-04, ASU 2019-05, and ASU 2020-02. The objective of the standard is to provide information about expected credit losses on financial instruments at each reporting date and to change how other-than-temporary impairments on investment securities are recorded. The ASU will become effective to the Company beginning on January 1, 2023, with early adoption permitted. The Company is currently evaluating the potential impacts of the ASU on its financial condition, results of operations, cash flows and financial statement disclosures. Although there were several other new accounting pronouncements issued or proposed by the FASB, the Company does not believe any of these have had or will have material impact on its consolidated financial statements.

Fair Value (Tables)

12 Months Ended

Dec. 31, 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 December 31, 2020 (in thousands):

	December 31, 2020
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	5		—		—		$	5
Commercial paper	2		44,318		—		(2	)		44,316
U.S. government debt and agency securities	2		4,999		—		—			4,999
U.S. treasury bills	2		4,450		—		—			4,450
Total cash equivalents		$	53,772	$	—	$	(2	)	$	53,770
Short-term investments:
Commercial paper	2		77,272		1		(4	)		77,269
U.S. government debt and agency securities	2		31,835		7		—			31,842
U.S. treasury bills	2		14,029		—		(3	)		14,026
Corporate bonds	2		920		—		—			920
Total short-term investments		$	124,056	$	8	$	(7	)	$	124,057
Long-term investments:
U.S. government debt and agency securities	2		78,924		32		—			78,956
U.S. treasury bills	2		4,551		2		—			4,553
Total long-term investments		$	83,475	$	34	$	—		$	83,509

Grant Liability

Schedule of Fair Value Liabilities, Activity

The following table presents the activity for the grant liability for the years ended December 31, 2020 and 2019 (in thousands):

	Year Ended December 31, 2020			Year Ended December 31, 2019
Fair value at beginning of period	$	1,036		$	936
Change in fair value of grant liability		464			100
Grant liability settled upon completion of IPO		(1,500	)		—
Fair value at end of period	$	—		$	1,036

Derivative Liability

Schedule of Fair Value Liabilities, Activity

The following table presents the activity for the derivative liability for the years ended December 31, 2020 and 2019 (in thousands):

	Year Ended December 31, 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 for the year ended December 31, 2020 (in thousands):

	Year Ended December 31, 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	$	—

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2020

Property Plant And Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment consisted of the following (in thousands):

	December 31, 2020			December 31, 2019
Laboratory equipment	$	81		$	69
Construction in progress		2,639			—
Property and equipment, as cost		2,720			69
Less: accumulated depreciation		(71	)		(69	)
Property and equipment, net	$	2,649		$	—

Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Payables And Accruals [Abstract]

Schedule of Accrued Expenses

Accrued expenses consisted of the following (in thousands):

	December 31, 2020		December 31, 2019
Employee compensation and benefits	$	1,624	$	230
Research and development expenses		1,169		536
Professional services and other		330		86
Total accrued expenses	$	3,123	$	852

Other Income (Expense), Net (Tables)

12 Months Ended

Dec. 31, 2020

Other Income And Expenses [Abstract]

Schedule of Other Income (Expense), Net

Other income (expense), net consisted of the following (in thousands):

	Year Ended December 31,
	2020			2019
Interest and other income		124			51
Interest expense		(367	)		(346	)
Change in fair value of derivative liability		(132	)		(71	)
Change in fair value of grant liability		(464	)		(100	)
Change in convertible preferred stock warrant liability		(641	)		—
Gain on extinguishment of convertible notes		199			—
Total other income (expense), net	$	(1,281	)	$	(466	)

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2020

Commitments And Contingencies Disclosure [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):

	December 31, 2020
2021		233
2022		261
2023		269
2024		277
2025		286
Thereafter		494
Total undiscounted lease payments		1,820
Present value adjustment for minimum lease commitments		(429	)
Tenant improvement allowance receivable		(391	)
Net lease liability	$	1,000

Convertible Preferred Stock (Tables)

12 Months Ended

Dec. 31, 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

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

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+ Details

Common Stock (Tables)

12 Months Ended

Dec. 31, 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:

	December 31, 2020		December 31, 2019
Convertible preferred stock		—		2,617,386
Stock options outstanding		1,974,873		1,514,770
Shares available for future grant under the 2020 Equity Incentive Plan		3,742,234		399,737
Shares available for future grant under the Employee Stock Purchase Plan		323,000		—
Common stock warrants		—		3,310
Total		6,040,107		4,535,203

Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-based Compensation Expense Recognized

Stock‑based compensation expense recognized was as follows (in thousands):

	Year Ended December 31,
	2020		2019
Research and development	$	215	$	55
General and administrative		418		198
Total stock-based compensation expense	$	633	$	253

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:

	Year Ended December 31,
	2020			2019
Risk-free interest rate		0.49	%		1.60	%
Expected volatility		87.41	%		75.00	%
Expected term (in years)		6.87			6.50
Expected dividend yield		—			—

Summary of Option Activity

A summary of option activity for the year ended December 31, 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		(1,053,053	)		1,053,053			16.72
Exercised		—			(540,934	)		1.00
Forfeited/expired		52,016			(52,016	)		4.57
Balance at December 31, 2020		3,742,234			1,974,873		$	9.31		7.98	$	49,275
Expected to vest					1,315,050		$	13.67		9.31	$	27,398
Options exercisable					659,823		$	1.12		5.34	$	21,877

Summary of Stock Options Outstanding and Exercisable

Stock options outstanding and exercisable consisted of the following at December 31, 2020:

	Employees and Directors				Non-employees
Exercise Price ($)	Shares Outstanding		Shares Exercisable		Shares Outstanding		Shares Exercisable
0.16		75,660		75,660		12,610		12,610
0.48		162,353		162,353		—		—
1.00		—		—		37,830		37,830
1.04		70,931		70,931		31,525		31,525
1.19		52,045		46,685		34,677		34,677
1.31		63,050		63,050		—		—
1.35		294,760		40,139		116,642		63,837
1.49		31,525		10,508		—		—
17.00		737,052		10,015		195,453		—
22.22		29,618		—		—		—
23.79		1,400		—		—		—
29.41		27,742		—		—		—
Total		1,546,136		479,341		428,737		180,479

Summary of RSA Activity

A summary of RSA activity for the year ended December 31, 2020 was as follows:

	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 December 31, 2020		4,204		$	1.35

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Components of Income (Loss) Before Income Tax

The Company did not record a provision (benefit) for income taxes for the years ended December 31, 2020 and 2019. Net loss is attributable to the following tax jurisdictions (in thousands):

	Year Ended December 31,
	2020			2019
United States	$	(19,969	)	$	(5,161	)
Foreign		14			—
Net Loss	$	(19,955	)	$	(5,161	)

Schedule of Effective Income Tax Rate Reconciliation

The provision for income taxes differs from the amount expected by applying the federal statutory rates to the net loss before taxes as follows:

	Year Ended December 31,
	2020			2019
Federal statutory income tax rate		21.0	%		21.0	%
Non-deductible expenses and others		0.2			(0.6	)
Non-deductible expense related to the convertible notes and derivative liability		(1.0	)		(1.7	)
Non-deductible expense related to the grant liability		(0.1	)		(0.3	)
Tax credits		1.5			2.2
Change in valuation allowance		(21.6	)		(20.6	)
Effective income tax rate		—	%		—	%

Components of Deferred Tax Assets and Liabilities

The components of the Company’s deferred tax assets and liabilities were as follows (in thousands):

	Year Ended December 31,
	2020			2019
Deferred tax assets:
Net operating loss carryforwards	$	8,090		$	3,911
Research and development tax credit carryforwards		1,011			716
Accrued liabilities		295			90
Stock-based compensation		106			82
Operating lease liability		210			—
Other		72			3
Total deferred tax assets		9,784			4,802
Deferred tax liabilities:
Right of use asset		(197	)		—
Prepaid expenses and other		(489	)		(12	)
Total deferred tax liabilities		(686	)		(12	)
Less valuation allowance		(9,098	)		(4,790	)
Net deferred tax assets	$	—		$	—

Schedule of Unrecognized Tax Benefits for Uncertain Tax Positions

A reconciliation of the beginning and ending amount of unrecognized tax benefits for uncertain tax positions were as follows (in thousands):

	Year Ended December 31,
	2020		2019
Beginning balance	$	239	$	200
Additions for tax positions taken in the current year		98		39
Ending balance	$	337	$	239

Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Summary of Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders

	Year Ended December 31,
	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		1,974,873		1,514,770
Employee stock purchase plan		3,995		—
Common stock warrants		—		3,310
Total		1,983,072		4,143,873

Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands					12 Months Ended	117 Months Ended
	Oct. 16, 2020 USD ($) $ / shares shares	Sep. 22, 2020 USD ($) $ / shares shares	Sep. 16, 2020 USD ($) shares	Sep. 11, 2020	Dec. 31, 2020 USD ($) shares	Dec. 31, 2020 USD ($) shares	Sep. 23, 2020 shares	Dec. 31, 2019 shares	Dec. 31, 2018 shares
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
Proceeds from initial public offering, net of issuance costs \| $					$ 208,517
Loss on final re-measurement of fair value of warrant liability \| $					$ 641
Convertible preferred stock, shares outstanding					0	0		2,617,386
Net cash proceeds from issuance of convertible preferred stock, common stock warrants, and convertible notes \| $						$ 310,600
Cash, cash equivalents, and investments \| $					$ 268,200	$ 268,200
Convertible Preferred Stock
Description Of Business [Line Items]
Convertible preferred stock, shares outstanding								2,617,386	2,617,386
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]
Convertible preferred stock, shares outstanding							0
IPO
Description Of Business [Line Items]
Number of shares issued and sold		12,000,000
Public offering price per share \| $ / shares		$ 17.00
Proceeds from initial public offering, net of issuance costs \| $		$ 186,400
IPO \| Convertible Preferred Stock
Description Of Business [Line Items]
Common shares issued on conversion of convertible preferred stock		12,503,009
Underwriters’ Option
Description Of Business [Line Items]
Number of shares issued and sold	1,397,712
Public offering price per share \| $ / shares	$ 17.00
Proceeds from initial public offering, net of issuance costs \| $	$ 22,100

Significant Accounting Policies - Additional Information (Details)	1 Months Ended		12 Months Ended
	Mar. 22, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) Segment	Dec. 31, 2019 USD ($)	Jul. 01, 2020 USD ($)	Jan. 31, 2019 USD ($)
Basis Of Presentation And Significant Accounting Policies [Line Items]
Impairment losses			$ 0	$ 0
Grant liability		$ 1,500,000	$ 1,500,000
Unsecured related party note receivable				$ 36,000
Number of operating segments \| Segment			1
Lease, practical expedient, use of hindsight			true
Operating lease right-of-use asset		936,000	$ 936,000
Operating lease liabilities		$ 1,000,000	$ 1,000,000
Unsecured Related Party Note Receivable
Basis Of Presentation And Significant Accounting Policies [Line Items]
Debt instrument, interest rate				1.45%
ASU 2016-02
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted		true	true
Change in accounting principle, accounting standards update, adoption date		Jan. 01, 2020	Jan. 01, 2020
Operating lease right-of-use asset					$ 1,000,000
Operating lease liabilities					$ 1,000,000
ASU 2018-07
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted		true	true
Change in accounting principle, accounting standards update, adoption date		Jan. 01, 2020	Jan. 01, 2020
Change in accounting principle, accounting standards update, material impact		true	true
ASU 2018-13
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted		true	true
Change in accounting principle, accounting standards update, adoption date		Jan. 01, 2020	Jan. 01, 2020
Change in accounting principle, accounting standards update, material impact		true	true
ASU 2019-12
Basis Of Presentation And Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adoption date		Jan. 01, 2020	Jan. 01, 2020
Change in accounting principle, accounting standards update, early adopted		true	true
Alzheimers Association
Basis Of Presentation And Significant Accounting Policies [Line Items]
Research grant awarded						$ 1,000,000
Grants received				$ 776,000
Grant income recognized			$ 246,000	754,000
Qualifying expenses incurred in excess of cash received			224,000
Alzheimers Association \| Subsequent Event
Basis Of Presentation And Significant Accounting Policies [Line Items]
Grants received	$ 224,000
Alzheimers Association \| Accrued Expenses
Basis Of Presentation And Significant Accounting Policies [Line Items]
Cash received in excess of expenses				$ 22,000
National Institute on Aging of the National Institutes of Health
Basis Of Presentation And Significant Accounting Policies [Line Items]
Research grant awarded		$ 15,200,000	15,200,000
Grants received		7,800,000
Remaining grant to be received		$ 7,400,000
National Institute on Aging of the National Institutes of Health \| Grant
Basis Of Presentation And Significant Accounting Policies [Line Items]
Grant income recognized			1,100,000
National Institute on Aging of the National Institutes of Health \| Unbilled Grant Receivable
Basis Of Presentation And Significant Accounting Policies [Line Items]
Qualifying expenses incurred in excess of cash received			$ 1,100,000
Minimum
Basis Of Presentation And Significant Accounting Policies [Line Items]
Property and equipment useful life			3 years
Maximum
Basis Of Presentation And Significant Accounting Policies [Line Items]
Property and equipment useful life			5 years

Fair Value - Schedule of Fair Value of Cash Equivalents, Short-term Investments and Long-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	$ 60,625	$ 2,056
Recurring Basis \| Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	53,772
Cash equivalents, Unrealized Losses	(2)
Cash equivalents, Fair Value	53,770
Recurring Basis \| Cash Equivalents \| Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value		$ 894,000
Recurring Basis \| Cash Equivalents \| Money Market Fund \| Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	5
Cash equivalents, Fair Value	5
Recurring Basis \| Cash Equivalents \| Commercial Paper \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	44,318
Cash equivalents, Unrealized Losses	(2)
Cash equivalents, Fair Value	44,316
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	4,999
Cash equivalents, Fair Value	4,999
Recurring Basis \| Cash Equivalents \| U.S. Treasury Bills \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Amortized Cost	4,450
Cash equivalents, Fair Value	4,450
Recurring Basis \| Short-term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	124,056
Investments, Unrealized Gains	8
Investments, Unrealized Losses	(7)
Fair Value	124,057
Recurring Basis \| Short-term Investments \| Commercial Paper \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	77,272
Investments, Unrealized Gains	1
Investments, Unrealized Losses	(4)
Fair Value	77,269
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	31,835
Investments, Unrealized Gains	7
Fair Value	31,842
Recurring Basis \| Short-term Investments \| U.S. Treasury Bills \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	14,029
Investments, Unrealized Losses	(3)
Fair Value	14,026
Recurring Basis \| Short-term Investments \| Corporate Bond Securities \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	920
Fair Value	920
Recurring Basis \| Long Term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	83,475
Investments, Unrealized Gains	34
Investments, Fair Value	83,509
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	78,924
Investments, Unrealized Gains	32
Investments, Fair Value	78,956
Recurring Basis \| Long Term Investments \| U.S. Treasury Bills \| Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments, Amortized Cost	4,551
Investments, Unrealized Gains	2
Investments, Fair Value	$ 4,553

Fair Value - Additional Information (Details) - USD ($)	12 Months Ended
Fair Value - Additional Information (Details) - USD ($)	Dec. 31, 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			$ 17.00
Grant Liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Additional grant liability	$ 464,000	$ 100,000
Total grant liability	1,500,000	1,036,000		$ 936,000
Recurring Basis \| Cash Equivalents
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value	$ 53,770,000
Recurring Basis \| Cash Equivalents \| Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash equivalents, Fair Value		$ 894,000,000
Recurring Basis \| Minimum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term investments effective maturity date	1 year
Recurring Basis \| Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Short-term investments effective maturity date	1 year
Long-term investments effective maturity date	2 years

Fair Value - Schedule of Fair Value Liabilities, Activity for Grant Liability (Details) - Grant Liability - USD ($)	12 Months Ended
	Dec. 31, 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	100,000
Settlement	(1,500,000)
Fair value at end of period	$ 1,500,000	$ 1,036,000

Fair Value - Schedule of Fair Value Liabilities, Activity for Derivative Liability (Details) - Derivative Liability - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 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 Value Liabilities, Activity for Convertible Preferred Stock Warrant Liability (Details) - Convertible Preferred Stock Warrant Liability $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Derivative liability recorded upon issuance of convertible notes	$ 364
Change in fair value of liability	641
Settlement	$ (1,005)

Property and Equipment, Net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, as cost	$ 2,720	$ 69
Less: accumulated depreciation	(71)	(69)
Property and equipment, net	2,649
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, as cost	81	$ 69
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, as cost	$ 2,639

Property and Equipment, Net - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation expense	$ 2,000	$ 2,000

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Employee compensation and benefits	$ 1,624	$ 230
Research and development expenses	1,169	536
Professional services and other	330	86
Total accrued expenses	$ 3,123	$ 852

Other Income (Expense), Net - Schedule of Other Income (Expense), Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Income And Expenses [Abstract]
Interest and other income	$ 124	$ 51
Interest expense	(367)	(346)
Change in fair value of derivative liability	(132)	(71)
Change in fair value of grant liability	(464)	(100)
Change in convertible preferred stock warrant liability	(641)
Gain on extinguishment of convertible notes	199
Total other income (expense), net	$ (1,281)	$ (466)

Significant Agreements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Change in fair value of grant liability	$ 464,000	$ 100,000
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
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		1,000,000			$ 1,500,000
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	$ 464,000	$ 100,000

Convertible Notes - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Gain on extinguishment of convertible notes		$ 199,000
Unsecured Convertible Notes
Debt Instrument [Line Items]
Debt instrument, principal amount		$ 1,700,000	$ 900,000	$ 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 convertible notes	$ 199,000
Unsecured Convertible Notes \| Series B-1 Convertible Preferred Stock
Debt Instrument [Line Items]
Debt conversion, converted instrument, shares issued	512,858

Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee Lease Description [Line Items]
Operating lease expense	$ 85,000
Short term leases, rent expense	76,000	$ 97,000
Variable lease expense	0
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
Operating lease existence of option to extend	true
Operating lease, additional term of contract	5 years
Operating lease, remaining lease term	6 years 8 months 12 days
Incremental borrowing rate	8.20%
Laboratory and Office Facilities \| University of Washington, Seattle
Lessee Lease Description [Line Items]
Operating lease initial term	12 months

Commitment and Contingencies - Reconciliation of Undiscounted Operating Lease Cash Flows to Operating Lease Liability Payments (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Leases [Abstract]
2021	$ 233
2022	261
2023	269
2024	277
2025	286
Thereafter	494
Total undiscounted lease payments	1,820
Present value adjustment for minimum lease commitments	(429)
Tenant improvement allowance receivable	(391)
Net lease liability	$ 1,000

Convertible Preferred Stock - Schedule of Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Dec. 31, 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 - Additional Information (Details) - USD ($)	2 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 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 Reserved Shares of Common Stock for Future Issuance (Details) - shares	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Reserved shares of common stock for future issuance	6,040,107	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	1,974,873	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	3,742,234	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 - Stock-based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 633	$ 253
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	215	55
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 418	$ 198

Stock-based Compensation - Additional Information (Details) - USD ($)		1 Months Ended	12 Months Ended
	Jan. 01, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield			0.00%	0.00%
Fair value of options vested			$ 271,000	$ 183,000
Aggregate intrinsic value of options exercised			18,000,000	$ 39,000
Unrecognized compensation cost			$ 3,900,000
Remaining weighted-average period expected to recognize unrecognized compensation cost			1 year 9 months
Reserved shares of common stock for future issuance			6,040,107	4,535,203
Common stock available for future grants			3,742,234	399,737
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Offering periods		6 months
Percentage of fair market value of common shares		85.00%
Offering period end date		May 18, 2021
Reserved shares of common stock for future issuance			323,000
Terms of award			Under the ESPP, eligible employees can authorize payroll deductions for amounts up to the lesser of 15% of their qualifying wages or the statutory limit under the U.S. Internal Revenue Code. The ESPP provides for offering periods of six months in duration with one purchase period per offering period beginning May 18 and November 18 of each year.
2020 Employee Stock Purchase Plan \| Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair market value of common shares	1.00%
Common stock available for future grants	324,851
2020 Employee Stock Purchase Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum percentage of payroll deductions for qualifying wages or statutory limit		15.00%
Shares of common stock purchased by each participant		5,000
2020 Employee Stock Purchase Plan \| Maximum \| Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of common stock for future issuance	646,000
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			$ 3,400,000	$ 274,000
Fair value of options vested			191,000	104,000
Advisors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant-date fair value of options granted			818,000	47,000
Fair value of options vested			$ 80,000	$ 79,000
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 - Weighted-Average Assumptions used in Estimating Fair Value of each Stock Options using Black-Scholes Option-Pricing Model (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.49%	1.60%
Expected volatility	87.41%	75.00%
Expected term (in years)	6 years 10 months 13 days	6 years 6 months
Expected dividend yield	0.00%	0.00%

Stock-based Compensation - Summary of Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
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	(1,053,053)
Available for Grant, Forfeited/expired	52,016
Available for Grant, Ending Balance	3,742,234	399,737
Shares, Beginning Balance	1,514,770
Shares, Granted	1,053,053
Shares, Exercised	(540,934)
Shares, Forfeited/expired	(52,016)
Shares, Ending Balance	1,974,873	1,514,770
Shares, Expected to vest	1,315,050
Shares, Options exercisable	659,823
Weighted-Average Exercise price per Share, Beginning Balance	$ 1.03
Weighted-Average Exercise price per Share, Granted	16.72
Weighted-Average Exercise price per Share, Exercised	1.00
Weighted-Average Exercise price per Share, Forfeited/expired	4.57
Weighted-Average Exercise price per Share, Ending Balance	9.31	$ 1.03
Weighted-Average Exercise price per Share, Expected to vest	13.67
Weighted-Average Exercise price per Share, Options exercisable	$ 1.12
Weighted-Average Remaining Contractual Term (in years)	7 years 11 months 23 days	7 years 1 month 28 days
Weighted-Average Remaining Contractual Term, Expected to vest (in years)	9 years 3 months 21 days
Weighted-Average Remaining Contractual Term, Options exercisable (in years)	5 years 4 months 2 days
Aggregate Intrinsic Value, Beginning Balance	$ 500
Aggregate Intrinsic Value, Ending Balance	49,275	$ 500
Aggregate Intrinsic Value, Expected to vest	27,398
Aggregate Intrinsic Value, Options exercisable	$ 21,877

Stock-based Compensation - Summary of Stock Options Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	1,974,873	1,514,770
Shares, Options exercisable	659,823
Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	1,546,136
Shares, Options exercisable	479,341
Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	428,737
Shares, Options exercisable	180,479
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, Options 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	12,610
Shares, Options exercisable	12,610
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, Options exercisable	162,353
Exercise Price $1.00
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 1.00
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, Options 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	70,931
Shares, Options exercisable	70,931
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, Options 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	52,045
Shares, Options exercisable	46,685
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, Options 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, Options 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	294,760
Shares, Options exercisable	40,139
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, Options exercisable	63,837
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, Options exercisable	10,508
Exercise Price $17.00
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 17.00
Exercise Price $17.00 \| Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	737,052
Shares, Options exercisable	10,015
Exercise Price $17.00 \| Non-employees
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	195,453
Exercise Price $22.22
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 22.22
Exercise Price $22.22 \| Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	29,618
Exercise Price $23.79
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 23.79
Exercise Price $23.79 \| Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	1,400
Exercise Price $29.41
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price ($)	$ 29.41
Exercise Price $29.41 \| Employees and Directors
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Shares Outstanding	27,742

Stock-based Compensation - Summary of RSA Activity (Details) - Restricted Stock Award (RSA)	12 Months Ended
	Dec. 31, 2020 $ / shares shares
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

Income Taxes - Components of Income (Loss) Before Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
United States	$ (19,969)	$ (5,161)
Foreign	14
Net Loss	$ (19,955)	$ (5,161)

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%
Non-deductible expenses and others	0.20%	(0.60%)
Non-deductible expense related to the convertible notes and derivative liability	(1.00%)	(1.70%)
Non-deductible expense related to the grant liability	(0.10%)	(0.30%)
Tax credits	1.50%	2.20%
Change in valuation allowance	(21.60%)	(20.60%)

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 8,090	$ 3,911
Research and development tax credit carryforwards	1,011	716
Accrued liabilities	295	90
Stock-based compensation	106	82
Operating lease liability	210
Other	72	3
Total deferred tax assets	9,784	4,802
Deferred tax liabilities:
Right of use asset	(197)
Prepaid expenses and other	(489)	(12)
Total deferred tax liabilities	(686)	(12)
Less valuation allowance	$ (9,098)	$ (4,790)

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Contingency [Line Items]
Change in valuation allowance	$ 4,300,000	$ 1,100,000
Net operating loss carryforwards	29,100,000
Material interest and penalties on uncertain tax benefits	0
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	9,400,000
Tax credit carryforwards	$ 1,300,000
Minimum \| Federal
Income Tax Contingency [Line Items]
Net operating loss and tax credit carryforwards, expiration period	11 years
Maximum \| Federal
Income Tax Contingency [Line Items]
Net operating loss and tax credit carryforwards, expiration period	17 years

Income Taxes - Schedule of Unrecognized Tax Benefits for Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Beginning balance	$ 239	$ 200
Additions for tax positions taken in the current year	98	39
Ending balance	$ 337	$ 239

Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
Employee Benefit Plans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Employee Benefit Plans [Abstract]
Percentage of pretax compensation eligible to defer	100.00%
Matching contributions	$ 0	$ 0

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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 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	1,983,072	4,143,873
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	1,974,873	1,514,770
Employee Stock Purchase Plan
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	3,995
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 Information (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
	Feb. 28, 2021	Jan. 25, 2021	Oct. 16, 2020	Dec. 31, 2020
Subsequent Event [Line Items]
Net proceeds from public offering				$ 208,517
Underwriters’ Option
Subsequent Event [Line Items]
Number of shares issued and sold			1,397,712
Public offering price per share			$ 17.00
Net proceeds from public offering			$ 22,100
Subsequent Event \| Underwriters’ Option
Subsequent Event [Line Items]
Number of shares issued and sold	600,000	4,000,000
Public offering price per share	$ 22.50	$ 22.50
Net proceeds from public offering	$ 12,700	$ 84,100