0000950170-22-003582 | 10-K | XBRL Viewer

Print Document View Excel Document

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 42,748	$ 157,150
Short-term investments	46,221
Prepaid expenses	2,530	2,971
Other current assets	396	276
Total current assets	91,895	160,397
Restricted cash	216	216
Right-of-use assets	1,479	1,793
Long-term investments	32,459
Other assets	437	477
Total assets	126,486	162,883
Current liabilities:
Accounts payable	2,823	3,628
Term loan, current portion		2,554
Accrued expenses and other current liabilities	4,613	2,496
Accrued compensation and benefits	1,435	1,085
Total current liabilities	8,871	9,763
Term loan, net of current portion	4,878	1,922
Lease liability, net of current portion	1,293	1,653
Other liabilities	73	118
Total liabilities	15,115	13,456
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000,000 shares and 0 shares authorized as of December 31, 2021 and 2020, respectively; 0 shares issued and outstanding as of December 31, 2021 and 2020
Common stock, $0.0001 par value; 200,000,000 shares authorized as of December 31, 2021 and 2020, respectively; 23,491,881 shares and 23,260,399 shares issued and outstanding as of December 31, 2021 and 2020, respectively	3	2
Additional paid-in capital	214,685	210,266
Accumulated other comprehensive loss	(184)
Accumulated deficit	(103,133)	(60,841)
Total stockholders’ equity (deficit)	111,371	149,427
Total liabilities, redeemable convertible preferred stock and stockholders’ equity (deficit)	$ 126,486	$ 162,883

BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Preferred Stock, Par Value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	23,491,881	23,260,399
Common stock, shares outstanding	23,491,881	23,260,399

STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 30,698	$ 23,854
General and administrative	11,368	5,562
Total operating expenses	42,066	29,416
Loss from operations	(42,066)	(29,416)
Interest expense	(345)	(323)
Other income, net	119	200
Net loss	(42,292)	(29,539)
Other comprehensive loss:
Unrealized loss on available for sale securities	(184)
Total comprehensive loss	$ (42,476)	$ (29,539)
Net loss per share, basic and diluted	$ (1.81)	$ (4.93)
Weighted-average shares of common stock outstanding, basic and diluted	23,361,416	5,991,213

STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Initial Public Offering	Series A Redeemable Convertible Preferred Stock	Series A Redeemable Convertible Preferred Stock Initial Public Offering	Series B Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred Stock Initial Public Offering	Common Stock	Common Stock Initial Public Offering	Additional Paid-In Capital	Additional Paid-In Capital Initial Public Offering	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2019			$ 27,813								$ 0
Balance, Shares at Dec. 31, 2019			28,000,000
Balance at Dec. 31, 2019	$ (30,637)						$ 1		$ 664			$ (31,302)
Balance, Shares at Dec. 31, 2019							764,408
Issuance of redeemable convertible preferred stock, net of issuance costs					$ 87,633
Issuance of redeemable convertible preferred stock, net of issuance costs, Shares					73,333,330
Temporary equity, Conversion of redeemable convertible preferred stock into common stock upon initial public offering				$ (27,813)		$ (87,633)
Temporary equity, Conversion of redeemable convertible preferred stock into common stock upon initial public offering, Shares				(28,000,000)		(73,333,330)
Conversion of redeemable convertible preferred stock into common stock upon initial public offering		$ 115,446						$ 1		$ 115,445
Conversion of redeemable convertible preferred stock into common stock upon initial public offering, Shares								15,492,019
Initial public offering of common stock, net of underwriting expenses and offering costs of $10,149		$ 93,351								$ 93,351
Initial public offering of common stock, net of underwriting expenses and offering costs of $10,149, Shares								6,900,000
Exercise of common stock warrant, Shares							46,358
Exercise of common stock options	51								51
Exercise of common stock options, Shares							57,614
Stock-based compensation	755								755
Net loss	(29,539)											(29,539)
Balance at Dec. 31, 2020	$ 149,427						$ 2		210,266			(60,841)
Balance, Shares at Dec. 31, 2020	23,260,399						23,260,399
Exercise of common stock options	$ 328						$ 1		327
Exercise of common stock options, Shares							211,439
Issuance of common stock related to employee stock purchase plan	134								134
Issuance of common stock related to employee stock purchase plan,shares							20,043
Stock-based compensation	3,958								3,958
Unrealized loss on available for sale securities	(184)										(184)
Net loss	(42,292)											(42,292)
Balance at Dec. 31, 2021	$ 111,371						$ 3		$ 214,685		$ (184)	$ (103,133)
Balance, Shares at Dec. 31, 2021	23,491,881						23,491,881

STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Underwriting expenses and offering costs	$ 10,149
Series B Convertible Preferred Stock
Stock issuance costs	$ 367

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (42,292)	$ (29,539)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	3,958	755
Depreciation and amortization	68	36
Amortization of premium on available-for-sale investments	121
Non-cash lease expense	313	66
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	415	(2,883)
Accounts payable and accrued expenses	1,149	3,733
Accrued compensation and benefits	350	177
Other assets	197	(6)
Other liabilities	(156)	142
Net cash used in operating activities	(35,877)	(27,519)
Cash flows from investing activities
Purchases of property and equipment	(93)	(74)
Purchases of investments	(79,075)
Net cash used in investing activities	(79,168)	(74)
Cash flows from financing activities
Proceeds from initial public offering, net of underwriting discounts commissions, and offering expenses		93,351
Proceeds from issuance of term loan, net of issuance costs of $10	4,990
Repayment of term loan	(4,770)
Proceeds from exercise of common stock options	328	51
Proceeds from issuance of common stock related to employee stock purchase plan	134
Payment of deferred offering costs	39
Net cash provided by financing activities	643	181,035
Net increase (decrease) in cash, cash equivalents and restricted cash	(114,402)	153,442
Cash, cash equivalents, and restricted cash at beginning of period	157,366	3,924
Cash, cash equivalents, and restricted cash at end of period	42,964	157,366
Supplemental cash flow data:
Cash paid for interest	207	192
Supplemental disclosure of non-cash investing and financing activities:
Deferred offering costs included in accrued expenses	$ 52
Right-of-use assets recognized in exchange for lease liabilities		1,858
Series A Redeemable Convertible Preferred Stock
Supplemental disclosure of non-cash investing and financing activities:
Conversion of redeemable convertible preferred stock to common stock upon initial public offering		27,813
Series B Redeemable Convertible Preferred Stock
Cash flows from financing activities
Proceeds from issuance of Series B redeemable convertible preferred stock, net of issuance costs		87,633
Supplemental disclosure of non-cash investing and financing activities:
Conversion of redeemable convertible preferred stock to common stock upon initial public offering		$ 87,633

STATEMENTS OF CASH FLOWS (Parenthetical) $ in Thousands	12 Months Ended
STATEMENTS OF CASH FLOWS (Parenthetical) $ in Thousands	Dec. 31, 2021 USD ($)
Statement Of Cash Flows [Abstract]
Proceeds from issuance of term loan, issuance costs	$ 10

Organization and Principal Activities

12 Months Ended

Dec. 31, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization and Principal Activities

1. Organization and Principal Activities

Description of Business

Spruce Biosciences, Inc. (the Company) is a late-stage biopharmaceutical company focused on developing and commercializing novel therapies for rare endocrine disorders with significant unmet medical need. The Company is initially developing its wholly-owned product candidate, tildacerfont, as the potential first non-steroidal therapy to offer markedly improved disease control and reduce steroid burden for patients suffering from classic congenital adrenal hyperplasia (CAH) and polycystic ovary syndrome (PCOS). The Company is located in Daly City, California and was incorporated in the state of Delaware in April 2016.

Initial Public Offering

In October 2020, the Company consummated its IPO and issued a total of 6,900,000 shares of common stock, which includes 900,000 shares issued pursuant to the exercise of the underwriters’ option to purchase additional shares, at an offering price of $15.00 per share. In aggregate, the Company received net proceeds of $93.4 million, after deducting underwriting discounts and commissions and offering expenses. Upon the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock automatically converted into 15,492,019 shares of common stock.

Liquidity and Capital Resources

As of December 31, 2021, the Company had cash, cash equivalents and investments of $121.4 million, which is sufficient to fund its planned operations for a period of at least twelve months following the issuance of the accompanying financial statements.

The Company has incurred significant losses and negative cash flows from operations. During the year ended December 31, 2021, the Company incurred a net loss of $42.3 million and used $35.9 million of cash in operations. As of December 31, 2021, the Company had an accumulated deficit of $103.1 million and does not expect positive cash flows from operations in the foreseeable future. The Company has funded its operations primarily through the issuance and sale of redeemable convertible preferred stock, debt, and the IPO. In February 2020, the Company issued and sold 36,666,665 shares of Series B redeemable convertible preferred stock (Series B preferred stock) for approximately $43.6 million in net proceeds. In August 2020, the Company issued and sold an additional 36,666,665 shares of Series B preferred stock for approximately $44.0 million in net proceeds.

The Company anticipates that it will need to raise substantial additional financing in the future to fund its operations. In order to meet these additional cash requirements, the Company may seek to sell additional equity or issue debt, convertible debt or other securities that may result in dilution to its stockholders. If the Company raises additional funds through the issuance of debt or convertible debt securities, these securities could have rights senior to those of its shares of common stock and could contain covenants that restrict its operations. There can be no assurance that the Company will be able to obtain additional equity or debt financing on terms acceptable to it, if at all. Debt financing, if available, would result in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions such as incurring debt, making capital expenditures or declaring dividends. The Company’s failure to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on its business, results of operations, and financial condition.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented.

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, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and development expenses, valuation of common stock and stock-based compensation, valuation of warrants and income tax and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates.

Risks and Uncertainties

Any product candidates developed by the Company will require approvals from the U.S. Food and Drug Administration (FDA) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If approval is denied or delayed, it may have a material adverse impact on the Company’s business and its financial statements.

The Company is subject to a number of risks similar to other late-stage biopharmaceutical companies including, but not limited to, dependency on the clinical and commercial success of the Company’s product candidate, tildacerfont, ability to obtain regulatory approval of tildacerfont, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition and untested manufacturing capabilities, and dependence on key individuals and sole source suppliers.

The Company’s business has been and could continue to be adversely affected by the evolving COVID-19 pandemic. For example, the COVID-19 pandemic has resulted in and could result in further delays to the Company’s clinical trials for numerous reasons including additional delays or difficulties in enrolling patients, diversion of healthcare resources away from the conduct of clinical trials, interruption or delays in the operations of the FDA or other regulatory authorities, and delays in clinical sites receiving the supplies and materials to conduct our clinical trials. At this time, the extent to which the COVID-19 pandemic impacts the Company’s business will depend on future developments, which are highly uncertain. The Company will continue to evaluate the impact that these events could have on its future operations, financial position, and results of operations and cash flows.

Segment Reporting

The Company operates and manages its business as one operating segment, which is the business of developing and commercializing novel therapies for rare endocrine disorders with significant unmet medical need. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in the United States of America.

Cash and Cash Equivalents

The Company considers all highly liquid investments with remaining maturities at the date of purchase of three months or less to be cash equivalents. Cash equivalents consist of amounts invested in money market funds.

Restricted Cash

The Company has cash in a collateral account related to a letter of credit issued on behalf of the Company for the security deposit on the non-cancelable operating lease for an office facility. The collateralized cash in connection with the letter of credit was classified as restricted cash on the balance sheet as of December 31, 2021 based on the terms of the lease agreement, which expires in 2025, unless extended.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed statements of cash flows (in thousands):


	December 31,
	2021		2020
Cash and cash equivalents	$	42,748	$	157,150
Restricted cash		216		216
Total cash, cash equivalents and restricted cash	$	42,964	$	157,366

Fair Value of Financial Instruments

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value.

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

▪

Level 1—Quoted prices in active markets for identical assets and liabilities;

▪

Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and

▪

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company’s financial instruments primarily consist of cash and cash equivalents, prepaid expenses, accounts payable, term loan, and accrued expenses. The carrying value of cash and cash equivalents, prepaid expenses, accounts payable, and accrued expenses are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. The estimated fair value of the term loan is based on estimated interest rates currently available to the Company for debt with similar terms.

Property and Equipment, Net

Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is calculated using the straight-line method over the estimated useful life of the respective asset and begins at the time the asset is placed into service. Maintenance and repairs are charged to expense as incurred, and improvements are capitalized.

The useful lives of property and equipment are as follows:


Computer and office equipment	3 years
Computer software	3 years
Manufacturing machinery and equipment	7 years
Leasehold improvements	Lesser of lease term or 15 years
Furniture and fixtures	5 years

Concentration of Credit Risk

Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash, cash equivalents and investments. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheet. The Company has not experienced any losses in such accounts and management believes that the Company is not

exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

Leases

The Company adopted Accounting Standards Update (ASU), No. 2016-02, Leases (Topic 842) effective January 1, 2020.

The Company determines if an arrangement includes a lease at inception. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset includes any lease payments made and excludes lease incentives. The incremental borrowing rate is used in determining the present value of future payments. The Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. The lease terms may include options to extend or terminate the lease. Lease expense for minimum lease payments is recognized on a straight-line basis over the non-cancelable lease term. The Company has elected not to recognize a right-of-use asset and lease liability for short-term leases. A short-term lease is a lease with an expected lease term of 12 months or less and which does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercise. See Note 5 to these financial statements for additional detail.

Research and Development Expenses

Research and development costs are expensed as incurred. Research and development expenses include, but are not limited to, personnel costs, fees paid to external entities that conduct certain non-clinical and clinical development activities on our behalf, manufacturing costs, outside service and consulting costs, and allocated overhead, including rent. Assets acquired that are utilized in research and development that have no alternative future use are also expensed as incurred.

Accrued Research and Development Expenses

Clinical trial costs are charged to research and development expense as incurred. The Company accrues for expenses resulting from contracts with clinical research organizations (CROs), consultants, and clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to us under such contracts. The Company’s policy is to reflect the appropriate expense in the financial statements by matching the appropriate expenses with the period in which services and efforts are expended.

The CRO contracts generally include pass-through fees including, but not limited to, regulatory expenses, investigator fees, laboratory fees and other miscellaneous costs. The Company determines accrual estimates through reports from and discussion with clinical personnel and outside service providers as to the progress or state of completion of trials, or the services completed. The Company estimates accrued expenses as of each balance sheet date based on the facts and circumstances known at that time. The clinical trial accrual is dependent, in part, upon the receipt of timely and accurate reporting from the CROs and other third-party vendors.

If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments associated with licensing agreements to acquire exclusive licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternate commercial use are expensed as incurred. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered.

Income Taxes

The Company accounts for income taxes under the asset and liability method. The Company estimates actual current tax exposure together with assessing temporary differences resulting from differences in accounting for reporting purposes and tax purposes for certain items, such as accruals and allowances not currently deductible for tax purposes. These temporary differences result in deferred tax assets and liabilities. In general, deferred tax assets represent future tax benefits to be received when certain expenses previously recognized in the Company’s statements of operations become deductible expenses under applicable income tax laws or when net operating loss or credit carryforwards are utilized. Accordingly, realization of the Company’s deferred tax assets is dependent on future taxable income against which these deductions, losses and credits can be utilized.

The Company must assess the likelihood that the Company’s deferred tax assets will be recovered from future taxable income, and to the extent the Company believes that recovery is not likely, the Company establishes a valuation allowance. The assessment of whether or not a valuation allowance is required often requires significant judgment, including the forecast of future taxable income and on-going prudent and feasible tax planning initiatives. Based upon the weight of available evidence, the Company has determined that net deferred tax assets should be fully offset by a valuation allowance. When the Company establishes or reduces the valuation allowance against its net deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. As of December 31, 2021 and 2020, the Company maintains a full valuation allowance on its net deferred tax assets.

The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits.

Stock-Based Compensation

The Company has an equity incentive plan under which various types of equity-based awards including, but not limited to, incentive stock options, non-qualified stock options, and restricted stock units, may be granted to employees, non-employee directors, and non-employee consultants.

For equity awards granted to employees, non-employees, and directors, the Company recognizes compensation expense based on the estimated grant-date fair values.

The fair value of stock options and shares purchased under the Company’s employee stock purchase plan is determined using the Black-Scholes option pricing model. The Company recognizes compensation expense for stock options on a straight-line basis over the requisite service period of the award, which is typically four years.

The fair value of restricted stock units (RSUs), including RSUs subject to performance-based vesting conditions, is based on the grant-date fair value of the Company's stock price. The Company recognizes compensation expense for time-based RSUs over the requisite service period, which is generally the vesting period of the award.

For options and restricted stock that vest upon the satisfaction of certain performance conditions, the Company recognizes compensation expense when it becomes probable that the performance conditions will be met. When the criteria are deemed probable of being met, the Company records cumulative compensation expense in the period the performance criteria are deemed probable of being met and recognizes the remaining compensation expense on a straight-line basis over the remaining period for which the performance criteria are expected to be completed.

The Company’s determination of the fair value of stock options on the date of grant utilizes the Black-Scholes option-pricing model and is impacted by its common stock price as well as other variables including, but not limited to, expected term that options will remain outstanding, expected common stock price volatility over the term of the option awards, risk-free interest rates and expected dividends.

Net Loss per Share

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 during the period, without consideration for potentially dilutive securities. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, outstanding stock options, RSUs, and shares expected to be issued pursuant to the employee stock purchase plan are considered to be potentially dilutive securities. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods.

Commitments and Contingencies

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business. The Company evaluates the likelihood of an unfavorable outcome in legal or regulatory proceedings to which it is a party and records a loss contingency on an undiscounted basis when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These judgments are subjective and based on the status of such legal proceedings, the merits of the Company’s defenses, and consultation with legal counsel. Actual outcomes of these legal proceedings may differ materially from the Company’s estimates. The Company estimates accruals for legal expenses when incurred as of each balance sheet date based on the facts and circumstances known to the Company at that time.

Emerging Growth Company Status

The Company is an emerging growth company (EGC) as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act) and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards.

Recent Accounting Pronouncements Not Yet Adopted

In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires companies to measure credit losses utilizing a methodology that reflects expected credit losses and requires a consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for non-EGC’s electing to use the extended transition period for complying with new or revised accounting standards for fiscal years beginning after December 15, 2019, and for EGC’s for fiscal years beginning after December 15, 2022, with early adoption permitted. The Company expects to adopt this ASU on January 1, 2023. The Company is currently assessing the impact of adopting this standard, but based on a preliminary assessment, does not expect the adoption of this guidance to have a material impact on its financial statements.

Recently Adopted Accounting Pronouncements

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in ASU 2019-12 are intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. ASU 2019-12 is effective for public business entities for fiscal years beginning after December 15, 2020 and the Company adopted on January 1, 2021. The adoption did not have any impact on the Company's financial statements for the year ended December 31, 2021.

Cash Equivalents and Investments

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Cash Equivalents And Investments

3. Cash Equivalents and Investments

Cash equivalents consist of amounts invested in money market funds and are stated at fair value.

Investments comprise U.S. treasury securities, commercial paper, and corporate bonds, which are classified as available for sale securities.

The following table is a summary of amortized cost, unrealized gains and losses, and fair value (in thousands):


		December 31, 2021
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds		$	38,067	$	—	$	—		$	38,067
	Total cash equivalents		38,067		—		—			38,067
Commercial paper			33,973		—		—			33,973
Corporate bonds			6,285		—		(23	)		6,262
U.S. treasury securities			5,999		—		(13	)		5,986
	Total short-term investments		46,257		—		(36	)		46,221
Corporate bonds			8,470		—		(34	)		8,436
U.S. treasury securities			24,137		—		(114	)		24,023
	Total long-term investments		32,607		—		(148	)		32,459
Total cash equivalents and available for sale securities		$	116,931	$	—	$	(184	)	$	116,747

As of December 31, 2021, the weighted-average remaining contractual maturities of available for sale securities was approximately 11 months.

There have been no realized gains or losses on available for sale securities for the periods presented. No available for sale securities held as of December 31, 2021 have been in a continuous unrealized loss position for more than 12 months, and unrealized gains and losses are included in “accumulated other comprehensive loss” within stockholders' equity on the condensed balance sheets. As of December 31, 2021, unrealized losses on available for sale securities are not attributed to credit risk and are considered temporary. The Company believes that it is more-likely-than-not that investments in an unrealized loss position will be held until maturity or the cost basis of the investment will be recovered. The Company believes it has no other-than-temporary impairments on its securities as it does not intend to sell these securities and does not believe it is more likely than not that it will be required to sell these securities before the recovery of their amortized cost basis. To date, the Company has not recorded any impairment charges on securities related to other-than-temporary declines in fair value. The Company’s cash equivalents and short-term investments are due within one year.

Fair Value Measurements

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

The carrying value of cash and cash equivalents, prepaid expenses, accounts payable, term loan, and accrued expenses are generally considered to be representative of their respective fair values because of the short-term nature of those instruments.

The following table summarizes the Company's financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		December 31, 2021
		Total		Level 1		Level 2		Level 3
Money market funds		$	38,067	$	38,067	$	—	$	—
	Total cash equivalents		38,067		38,067		—		—
Commercial paper			33,973		—		33,973		—
Corporate bonds			6,262		6,262				—
U.S. treasury securities			5,986		5,986		—		—
	Total short-term investments		46,221		12,248		33,973		—
Corporate bonds			8,436		8,436		—		—
U.S. treasury securities			24,023		24,023		—		—
	Total long-term investments		32,459		32,459		—		—
Total cash equivalents, short-term investments and long-term investments		$	116,747	$	82,774	$	33,973	$	-

The Company did not have any financial liabilities recorded at fair value on a recurring or non-recurring basis as of December 31, 2021 and 2020.

For Level 1 investments, the Company uses quoted prices in active markets for identical assets to determine the fair value. For Level 2 investments, the Company uses quoted prices for similar assets sourced from certain third-party pricing services. The third-party pricing services generally utilize industry standard valuation models for which all significant inputs are observable, either directly or indirectly, to estimate the price or fair value of the securities. The primary input generally includes reported trades of or quotes on the same or similar securities. The Company does not make additional judgments or assumptions made to the pricing data sourced from the third-party pricing services.

The estimated fair value of the term loan was $5.0 million as of December 31, 2021 and was based on estimated interest rates currently available to the Company for debt with similar terms, a Level 2 input.

- 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

Balance Sheet Components

12 Months Ended

Dec. 31, 2021

Balance Sheet Components Disclosure [Abstract]

Balance Sheet Components

5. Balance Sheet Components

Property and equipment, net

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


	December 31,
	2021			2020
Computer and office equipment	$	15		$	3
Computer software		27			10
Manufacturing machinery and equipment		58			4
Leasehold improvements		7			7
Furniture and fixtures		64			57
Less: accumulated depreciation		(31	)		(8	)
Property and equipment, net	$	140		$	73

Property and equipment, net is included in other assets on the balance sheets. Depreciation expense was $23 thousand and $5 thousand for the years ended December 31, 2021 and 2020, respectively.

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,
	2021		2020
Accrued research and development expenses	$	3,837	$	2,002
Accrued general and administrative expenses		416		245
Lease liability, current portion		360		249
Total accrued expenses and other current liabilities	$	4,613	$	2,496

Accrued research and development expenses were primarily related to clinical trials, preclinical studies, and manufacturing.

Leases

12 Months Ended

Dec. 31, 2021

Leases [Abstract]

Leases

6. Leases

The Company leases space under non-cancelable operating leases which require the Company to pay base rent, real estate taxes, insurance, general repairs, and maintenance. The Company does not have finance leases. The Company adopted ASC Topic 842 as of January 1, 2020.

In February 2020, the Company entered into a non-cancelable operating lease for office space with a commencement date of September 2020. The monthly payments escalate over the 63-month term with total gross commitments of $2.3 million. The lease includes an option to renew the lease term for an additional period of 60 months. The renewal option is not included in the lease term or minimum lease payments disclosures below as the Company is not reasonably certain to exercise the option. Lease incentives, which relate to rent abatement, were considered in the calculation of the lease liability and right-of-use asset. Lease expense for the year ended December 31, 2021 and 2020 was $0.4 million and $0.1 million, respectively.

Lease right-of-use assets and liabilities are recognized at the commencement date based on the present value of the remaining minimum lease payments over the lease term. As the leases do not provide an implicit rate, the Company uses a collateralized incremental borrowing rate based on the information available at the commencement date to determine the lease liability. As of December 31, 2021, the weighted-average remaining lease term for operating leases was 3.9 years and the weighted-average discount rate was 7.0%. Cash paid for amounts included in the measurement of lease liabilities was $0.3 million and $37 thousand for the year ended December 31, 2021 and 2020, respectively.

The Company recognizes monthly operating lease expense on a straight-line basis over the term of the lease. Variable lease expense relates primarily to office lease common area maintenance, insurance, and property taxes, is expensed as incurred, and is excluded from the calculation of the lease liability and right-of-use-asset. Variable lease expense for the year ended December 31, 2021 and 2020 was minimal.

Future minimum annual lease commitments under the Company’s non-cancelable operating leases as of December 31, 2021 were as follows (in thousands):


	Amount
2022	$	464
2023		478
2024		493
2025		464
2026		—
Total undiscounted future minimum lease payments		1,899
Less: present value discount		(246	)
Total discounted future minimum lease payments	$	1,653
Lease liability, current portion (included in "accrued expenses and other current liabilities" on the condensed balance sheet)	$	360
Lease liability, net of current portion		1,293
Total operating lease liability	$	1,653

Term Loan

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Term Loan

7. Term Loan

In September 2019, the Company entered into a Loan and Security Agreement (the Loan Agreement) with Silicon Valley Bank (SVB) providing for a term loan (the Term Loan). In April 2020, the Company and SVB entered into an agreement (the Deferral Agreement) whereby the parties agreed to extend the Interest-Only Period (defined below), repayment dates of all monthly payments of principal due and the maturity date with respect to the Term Loan by six months. All other terms of the Term Loan remained unchanged. The Deferral Agreement was determined to be a debt modification, resulting in a prospective yield adjustment based on the revised terms.

In connection with the Loan Agreement, the Company issued a warrant to purchase up to an aggregate of 49,609 shares of common stock at $1.44 per share. The Company determined the initial fair value of the warrant to be $0.1 million using the Black-Scholes option-pricing model. The fair value of the warrant was recorded to equity and as a debt discount, which was being amortized to interest expense using the effective interest method over the term of the Term Loan. In November 2020, the warrant was net-exercised for 46,358 shares of common stock.

In March 2021, the Company entered into a First Amendment to Loan and Security Agreement (the First Amendment), pursuant to which the Company and SVB amended the Loan Agreement. The First Amendment increased the aggregate principal amount of the Term Loan commitment by SVB to up to $30.0 million. Up to $20.0 million was available under the first tranche of the Term Loan (First Tranche), $5.0 million of which was advanced immediately to repay the outstanding obligations under the Term Loan prior to the First Amendment. The remainder of the First Tranche commitment, or $15.0 million, expired on December 31, 2021. Up to $10.0 million is available under the second tranche (Second Tranche), subject to the completion of certain clinical and financial milestones, which Second Tranche commitment is available through December 31, 2022. Pursuant to the First Amendment, the Term Loan will mature on January 1, 2026. The First Amendment was determined to be a debt modification.

Pursuant to the First Amendment, the Company is required to make monthly payments of interest only commencing on the first day of the month following the funding date of each respective tranche and continuing thereafter through December 31, 2022 to the extent that the Company does not borrow any part of the Second Tranche or December 31, 2023 if the Company has borrowed some or all of the Second Tranche. Outstanding principal balances under the Term Loan, as amended by the First Amendment, bear interest at a floating per annum rate equal to (A) if the Company does not borrow under the Second Tranche, the greater of (x) 1% above the prime rate or (y) 4.25%; or (B) if the Company does borrow under the Second Tranche, the greater of (x) 3% above the prime rate or (y) 6.25%.

Following the interest-only period, the outstanding Term Loan balance will be payable in (i) 37 consecutive monthly payments (or 25 if the Company borrows under the Second Tranche) after the end of the Interest-Only Period and continuing on the same day of each month thereafter, in amounts that would fully amortize such Term Loan balance, as of the first business day of the first month following the Interest-Only Period, over the repayment

period, plus (ii) monthly payments of accrued but unpaid interest. The final payment due on the maturity date shall include all outstanding principal and all accrued unpaid interest and an end of term payment totaling (x) 6% of the original funded principal amount of the First Tranche if the Company does not borrow under the Second Tranche, or (y) 9.5% of the total original funded principal amount under the First and Second Tranche if the Company does borrow under the Second Tranche (the End of Term Payment). The Company may prepay amounts outstanding under the Term Loan at any time provided certain notification conditions are met, in which case, all outstanding principal plus accrued and unpaid interest, the End of Term Payment, a prepayment fee between 1% and 3% of the commitment amount of the First and Second Tranches, and any bank expenses become due and payable.

The Company incurred $10.0 thousand of debt issuance costs in connection with the First Amendment and had unamortized issuance costs and unamortized debt discount under the Loan Agreement of $2.0 thousand and $16.0 thousand, respectively. The Company recorded these costs, including the unaccreted portion of the final payment obligation under the Loan Agreement as a discount from the carrying value of the Term Loan, which are being amortized using the effective interest method over the life of the First Amendment. The unamortized debt issuance costs and debt discount balance was $0.1 million as of December 31, 2021.

The Term Loan and unamortized discount and debt issuance costs balances as of December 31, 2021 are shown below (in thousands):


	December 31, 2021			December 31, 2020
Total Term Loan debt	$	5,000		$	4,500
Less: unamortized discount and debt issuance costs		(122	)		(24	)
Total Term Loan, net		4,878			4,476
Less: Term Loan, current portion		—			(2,554	)
Term loan, net of current portion	$	4,878		$	1,922

The Company is subject to customary affirmative and restrictive covenants under the Loan Agreement. The Company’s obligations under the Loan Agreement are secured by a first priority security interest in substantially all of its current and future assets, other than intellectual property. The Company also agreed not to encumber its intellectual property assets, except as permitted by the Loan Agreement.

The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, the Company’s failure to fulfill certain obligations under the Loan Agreement and the occurrence of a material adverse change in its business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of lender’s lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the lender would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement. As of December 31, 2021, management believes that the Company was in compliance with all financial covenants under the Loan Agreement and there had been no material adverse change.

As of December 31, 2021, future principal payments per year under the Term Loan were as follows (in thousands):


	Amount
2022	$	—
2023		1,622
2024		1,622
2025		1,621
2026		135
Total	$	5,000

The Company made interest payments on the Term Loan of $0.2 million and $0.2 million during the year ended December 31, 2021 and 2020, respectively.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI http://asc.fasb.org/topic&trid=2208564

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1E
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

Legal Matters

The Company’s industry is characterized by frequent claims and litigation, including claims regarding intellectual property. As a result, the Company may be subject to various legal proceedings from time to time. The results of any future litigation cannot be predicted with certainty, and regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. The Company was not subject to any material legal proceedings during the year ended December 31, 2021 and management is not aware of any pending or threatened litigation.

Capital Structure

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Capital Structure

9. Capital Structure

Common Stock

As of December 31, 2021 and 2020, the Company was authorized to issue 200,000,000 shares of $0.0001 par value common stock, respectively. Holders of the Company’s common stock are entitled to dividends if and when declared by the Board of Directors of the Company (Board of Directors) and after any redeemable convertible preferred share dividends are fully paid. The holder of each share of common stock is entitled to one vote. As of December 31, 2021, no dividends were declared.

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	December 31,
	2021		2020
Stock options, issued and outstanding		2,215,942		2,278,771
Restricted and performance stock units, issued and outstanding		460,000		—
Shares available for future issuance under 2020 Equity Incentive Plan		2,636,506		2,637,076
Employee stock purchase plan, available for future issuance		433,200		220,640
Total shares reserved		5,745,648		5,136,487

Redeemable Convertible Preferred Stock

Immediately prior to the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock converted into 15,492,019 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of redeemable convertible preferred stock outstanding as of December 31, 2021 and 2020.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-URI http://asc.fasb.org/topic&trid=2208762

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496180-112644

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Equity Incentive Plan and Stock-Based Compensation Expense

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Equity Incentive Plan and Stock-Based Compensation Expense

10. Equity Incentive Plan and Stock-Based Compensation Expense

2020 Equity Incentive Plan

The Company adopted the 2020 Equity Incentive Plan (the 2020 Plan) in October 2020. The 2020 Plan is a successor to and continuation of the Amended and Restated 2016 Equity Incentive Plan (the 2016 Plan) and provides for the granting of stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock or cash-based awards to individuals who are then employees, officers, directors or consultants. A total of 2,647,684 shares of common stock were approved to be initially reserved for issuance under the 2020 Plan. In addition, the number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year or such lesser amount as determined by the Company’s Board of Directors. Following the effectiveness of the 2020 Plan, no further grants will be made under the 2016 Plan; however, shares subject to awards granted under the 2016 Plan will continue to be governed by the 2016 Plan.

Under the Plan, the Board of Directors determines the per share exercise price of each stock option, which for ISOs shall not be less than 100% of the fair market value of a share on the date of grant; provided that the exercise price of an ISO granted to a stockholder who at the time of grant owns stock representing more than 10% of the voting power of all classes of stock (a 10% stockholder) shall not be less than 110% of the fair market value of a share on the date of grant.

The Board of Directors determines the period over which options vest and become exercisable. Options granted to new employees generally vest over a four-year period: 25% of the shares vest on the first anniversary from the vesting commencement date of the option and an additional 1/48th of the shares vest on each monthly anniversary thereafter, subject to the employee’s continuous service through each vesting date.

The Board of Directors also determines the term of options, provided the maximum term for ISOs granted to a 10% stockholder must be no longer than five years from date of grant and the maximum term for all other options must be no longer than ten years from date of grant. If an option holder’s service terminates, options generally terminate three months from the date of termination except under certain circumstances, such as death or disability.

Under the 2020 Plan and the 2016 Plan, individuals can be granted the ability to early exercise their options. There were no shares, related to the early exercise of options, subject to repurchase by the Company as of December 31, 2021. As of December 31, 2021, a total of 3,810,703 shares were authorized to be issued under the 2020 Plan and 2,636,506 shares remained available for issuance, and a total of 1,501,745 shares were authorized for issuance under the 2016 Plan and no shares remained available for issuance.

A summary of the Company’s stock option activity and related information is as follows (in thousands, except share and per share amounts):


	Outstanding Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Balance as of December 31, 2019		859,322		$	1.20		7.9	$	209
Granted		1,775,808			3.33		—		—
Exercised		(57,614	)		0.89		—		—
Forfeited/Cancelled		(298,745	)		1.86		—		—
Balance as of December 31, 2020		2,278,771			2.78		8.6	$	49,059
Granted		947,917			10.78		—		—
Exercised		(211,439	)		1.55		—		—
Forfeited/Cancelled		(799,307	)		7.30		—		—
Balance as of December 31, 2021		2,215,942		$	4.72		6.9	$	3,959
Vested and expected to vest as of December 31, 2021		2,181,939		$	4.72		6.9	$	3,959
Vested and exercisable as of December 31, 2021		961,313		$	3.54		3.9	$	2,209

Stock options vested and expected to vest differs from total stock options outstanding as it excludes performance-based stock options for which the performance criteria have not been achieved as of December 31, 2021.

The aggregate intrinsic values of options outstanding and exercisable were calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock as of the respective balance sheet date. The total intrinsic value of options exercised was $2.0 million and $0.3 million for the year ended December 31, 2021 and 2020, respectively.

The Company recognizes compensation expense for stock option awards granted to employees and non-employee on a straight-line basis over the requisite service period of the award, generally four years. During the years ended December 31, 2021 and 2020, the Company granted options to purchase an aggregate of 947,917 and 1,775,808 shares of common stock to grantees with a weighted-average exercise price of $10.78 and $3.33 per share, respectively. For the years ended December 31, 2021 and 2020, the weighted-average fair value of options granted was $8.55 and $3.56 per share, respectively, and was estimated using the Black-Scholes option-pricing model, with the following weighted-average assumptions:


	2021			2020
Expected term (in years)		6.0			6.0
Expected volatility		102.8	%		80.1	%
Risk-free interest rate		0.9	%		0.4	%
Expected dividend rate		0.0	%		0.0	%

Restricted Stock Units (RSUs)

A summary of the Company’s RSU activity and related information is as follows (in thousands, except share and per share amounts):


	RSUs
	Shares		Weight-Average Grant Date Fair Value Per Share
Unvested balance as of December 31, 2020		—	$	—
Granted		460,000		2.48
Vested		—		—
Forfeited		—		—
Unvested balance as of December 31, 2021		460,000	$	2.48

In December 2021, the Company granted 460,000 RSUs, including 230,000 RSUs subject to time-based vesting in installments through June 30, 2023, and 230,000 RSUs subject to performance-based vesting conditions related to the satisfaction of certain clinical development milestones.

2020 Employee Stock Purchase Plan

The Company’s Board of Directors adopted and the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the ESPP) in October 2020. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation. At the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock as of the offering date or the applicable purchase date. A total of 220,640 shares of common stock were approved to be initially reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lessor of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year, (ii) 441,280 shares of common stock or (iii) such lesser amount as determined by the Board of Directors.

Except for the initial offering period, the ESPP provides for 24-month offering periods starting every January 1st and July 1st, each consisting of four six-month purchase periods. During the year ended December 31, 2021, 20,043 shares of common stock were issued under the ESPP. As of December 31, 2021, 433,200 shares of common stock remained available for issuance under the ESPP.

Fair Value of Stock Options and ESPP Shares

The fair market value of both stock options and the option component of shares purchased under the ESPP was estimated using the Black-Scholes option pricing model. The description of the significant assumptions used in the model are as follows:

▪

Expected Term. The expected term is based on the simplified method, as the Company’s stock options have the following characteristics: (i) granted at-the-money; (ii) exercisability is conditioned upon service through the vesting date; (iii) termination of service prior to vesting results in forfeiture; (iv) limited exercise period following termination of service; and (v) options are non-transferable and non-hedgeable, or “plain vanilla” options, and the Company has limited history of exercise data. For the ESPP, the expected term is based on the term of the purchase period.

▪

Expected Volatility. The expected volatility is estimated based on the historical volatilities for comparable publicly traded biopharmaceutical companies. In evaluating similarity, the Company considered factors such as market capitalization, stage of development, area of specialty, and stock-specific attributes. The Company will continue to analyze the historical stock price volatility and expected term assumptions as more historical data for the Company’s common stock becomes available.

▪

Risk-Free Interest Rate. The risk-free interest rate is based on U.S. Treasury constant maturity rates with remaining terms similar to the expected term of the options.

▪

Expected Dividend Rate. The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model.

▪

Forfeitures. The Company accounts for forfeitures as they occur.

The Company recognizes compensation expense for stock option awards granted on a straight-line basis over the requisite service period of the award, generally four years. During the years ended December 31, 2021 and 2020, the Company granted options to purchase an aggregate of 947,917 and 1,775,808 shares of common stock to grantees with a weighted-average exercise price of $10.78 and $3.33 per share, respectively.

For the years ended December 31, 2021 and 2020, the weighted-average fair value of options granted was $8.55 and $3.56 per share, respectively, and was estimated using the Black-Scholes option-pricing model, with the following weighted-average assumptions:


	2021			2020
Expected term (in years)		6.0			6.0
Expected volatility		102.8	%		80.1	%
Risk-free interest rate		0.9	%		0.4	%
Expected dividend rate		0.0	%		0.0	%

The Company recognizes compensation expense for its ESPP awards on a straight-line basis over the requisite service period for the entire award, typically two years. Total compensation expense related to the ESPP for the year ended December 31, 2021 and 2020 was $0.1 million and $32 thousand, respectively. The following assumptions were used to calculate stock-based compensation for each stock purchase right granted under the ESPP:


	2021			2020
Expected term (in years)		1.4			1.5
Expected volatility		78.7	%		90.8	%
Risk-free interest rate		0.1	%		0.2	%
Expected dividend rate		0.0	%		0.0	%

Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense recognized in the Company’s statement of operations during the years ended December 31, 2021 and 2020 (in thousands):


	Year Ended December 31,
	2021		2020
Research and development	$	1,045	$	327
General and administrative		2,913		428
Total stock-based compensation expense	$	3,958	$	755

During 2020, the Company granted options to purchase 127,042 shares of common stock to certain executive officers with performance criteria stipulating that no shares will vest unless certain financing and other related milestones are achieved. In January 2021, the Board determined that the performance-based vesting criteria of such options had been satisfied, which was deemed a modification. The fair value of the modified awards was $2.4 million. For the year ended December 31, 2021, the Company recorded stock-based compensation of $0.9 million in connection with the modification.

As of December 31, 2021, there was approximately $5.7 million of unrecognized stock-based compensation expense related to stock options, which is expected to be recognized over an estimated weighted-average vesting term of 2.8 years.

As of December 31, 2021, there was approximately $0.8 million of unrecognized stock-based compensation expense related to RSUs, which is expected to be recognized over an estimated weighted-average vesting term of 1.3 years.

License Agreement

12 Months Ended

Dec. 31, 2021

Research And Development [Abstract]

License Agreement

11. License Agreement

In May 2016, the Company entered into a license agreement (the License Agreement), with Eli Lilly and Company (Lilly). Pursuant to the terms of the License Agreement, Lilly granted the Company an exclusive, worldwide, royalty bearing, sublicensable license under certain technology, patent rights, know-how and proprietary materials related to certain compounds, to research, develop, and commercialize such compounds for all pharmaceutical uses.

As partial consideration for the rights granted to the Company under the License Agreement, the Company made a one-time upfront payment to Lilly of $0.8 million during the year ended December 31, 2016, which was recorded as research and development expense as there was no alternative use due to the early stage of the technology. The Company is also required to pay Lilly up to an aggregate of $23.0 million upon the achievement, during the time the License Agreement remains in effect, of certain milestones relating to the clinical development and commercial sales of products licensed under the License Agreement. Such payments are for predetermined fixed amounts, are paid only upon the first occurrence of each event, and are due shortly after achieving the applicable milestone. In addition, the Company is required to pay Lilly tiered royalties on annual worldwide net sales with rates ranging from mid-single-digits to sub-teens. No additional amounts were paid by the Company to Lilly during any of the periods presented, nor were due as of such dates pursuant to the License Agreement.

The License Agreement will remain in effect, unless earlier terminated, until the expiration of the royalty payment obligations. Royalties are payable on a product-by-product and country-by-country basis from the first commercial sale of the product until the later of (i) the tenth anniversary of the date of first commercial sale in such country, (ii) the expiration in such country of the last-to-expire licensed patent having a valid claim covering the manufacture, use or sale of the licensed product as commercialized in such country, and (iii) the expiration of any data or regulatory exclusivity period for the licensed product in such country.

Income Taxes

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

12. Income Taxes

The Company has incurred cumulative domestic net operating losses (NOL) since inception and, consequently, has no income tax expense for the years ended December 31, 2021 and 2020 due to its net operating loss position.

The reconciliation of the federal statutory income tax rate to the Company’s effective tax rate is as follows:


	December 31,
	2021				2020
Federal statutory tax rate		21.00		%		21.00		%
State tax, net of federal benefit		6.98		%		6.98		%
Nondeductible expenses		(0.38	)	%		(0.09	)	%
Tax credits		5.31		%		6.15		%
Change in valuation allowance		(32.96	)	%		(41.38	)	%
Prior year true-up for state net operating losses		-		%		6.96		%
Other		0.05		%		0.38		%
Effective tax rate		0		%		0		%

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Realization of deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. The net valuation allowance increased by approximately $13.9 million and $12.2 million during the years ended December 31, 2021 and 2020, respectively.

Significant components of the Company’s net deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	27,570		$	16,381
Accruals		99			326
Intangible assets		131			143
Tax credits		4,766			2,500
Lease liability		463
Other		785			109
Total gross deferred tax assets		33,814			19,459
Valuation allowance for deferred tax assets		(33,397	)		(19,459	)
Deferred tax liabilities:
Right-of-use assets		(414	)		—
Other		(3	)		—
Total deferred tax liabilities		(417	)		—
Total net deferred tax assets	$	—		$	—

As of December 31, 2021, the Company had federal net operating loss carryforwards of approximately $98.6 million and $98.4 million in state net operating loss carryforwards. If not utilized, the federal net operating loss carryforwards incurred before January 1, 2018 will begin to expire in 2036, and state net operating loss carryforwards will begin to expire in 2036. The federal net operating losses of $91.4 million incurred in 2018 and beyond do not expire.

Under Sections 382 and 383 of the Internal Revenue Code (IRC) of 1986, as amended (the Code), if a corporation undergoes an “ownership change,” the company’s ability to use its pre-change net operating loss carryforwards and other pre-change attributes, such as research tax credits, to offset its post-change income may be limited. In general, an “ownership change” will occur if there is a cumulative change in ownership by “5% shareholders” that exceeds 50 percentage points over a rolling three-year period. Tax credits are subject to IRC Section 383. In the event of a change in ownership as defined by this code section, the usage of the credits may be limited. Similar rules may apply under state tax laws. As of December 31, 2020, the Company determined that an ownership change occurred on May 2, 2016 and August 7, 2020. As a result of the ownership changes, the Company derecognized an immaterial amount of net operating loss-related deferred tax assets for federal and state purposes. The ability of the Company to use its remaining net operating loss carryforwards is subject to Section 382 limitation and may be further limited if the Company experiences a Section 382 ownership change as a result of future changes in its stock ownership.

As of December 31, 2021, the Company had federal and state tax credit carryforwards of approximately $5.6 million and $1.0 million, respectively. If not utilized, the federal tax credits will begin to expire in 2036 and the state tax credits do not expire. As a result of the previously mentioned ownership changes, the Company derecognized in 2020 approximately $2 thousand of gross federal tax credit-related deferred tax assets due to the Section 383 limitation. The Company has not derecognized any of the state tax credit-related deferred tax assets because the credits do not expire.

Uncertain Income Tax Positions

The Company accounts for uncertainty in income taxes in accordance with ASC 740. Tax positions are evaluated in a two-step process, whereby the Company first determines whether it is more likely than not that a tax position will be sustained upon examination by tax authorities, including resolutions of any related appeals or litigation processes, based on technical merit. If a tax position meets the more-likely-than-not recognition threshold, it is then measured to determine the amount of benefit to be recognized in the financial statements. The tax position is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement.

The Company does not expect the amount of unrecognized tax benefits to materially change in the next 12 months.

The Company had approximately $1.6 million and $1.1 million of unrecognized tax benefits as of December 31, 2021 and 2020, respectively. No liability related to uncertain tax positions is recorded in the financial statements due to the fact the liabilities have been netted against deferred attribute carryovers. The unrecognized tax benefits would not impact the annual effective tax rate if recognized because the Company has recorded a valuation allowance on its deferred tax assets.

A reconciliation of the beginning and ending balance of the unrecognized tax benefits is as follows (in thousands):


	December 31,
	2021			2020
Balance at the beginning of the year	$	1,094		$	398
Increase of unrecognized tax benefits taken in prior years		-			10
Decrease of unrecognized tax benefits taken in prior years		(198	)		-
Increase of unrecognized tax benefits related to current year		693			686
Balance at the end of the year	$	1,589		$	1,094

Interest and penalty related to unrecognized tax benefits would be included as income tax expense in the Company’s statements of operations. As of December 31, 2021 and 2020, the Company has not recognized any tax-related penalties or interest in its financial statements.

The Company files income tax returns in the U.S. federal jurisdiction and California state jurisdiction. The Company is not currently under audit by the Internal Revenue Service or any other similar state, local, or foreign authority. All tax years remain open to examination by major taxing jurisdictions to which the Company is subject.

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 270
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-URI http://asc.fasb.org/topic&trid=2144680

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

401(k) Retirement Savings Plan

12 Months Ended

Dec. 31, 2021

Compensation And Retirement Disclosure [Abstract]

401(k) Retirement Savings Plan

13. 401(k) Retirement Savings Plan

In December 2017, the Company adopted a 401(k) plan (the 401(k) Plan) for all employees who have met certain eligibility requirements. Under the agreement, employees may elect to contribute a portion of their eligible compensation, subject to certain limitations. The Company did not make any matching employer contributions to the 401(k) Plan as of and for the years ended December 31, 2021 and 2020.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section S99
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=21916913&loc=d3e273930-122802

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (o)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (p)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-URI http://asc.fasb.org/topic&trid=2235017

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39689-114964

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (q)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

Net Loss Per Share

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Net Loss Per Share

14. Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Year Ended December 31,
	2021			2020
Numerator:
Net loss	$	(42,292	)	$	(29,539	)
Denominator:
Weighted-average common shares outstanding		23,361,416			5,991,213
Net loss per share, basic and diluted	$	(1.81	)	$	(4.93	)

Basic net loss per share was the same as diluted net loss per share for all periods as the inclusion of potentially dilutive securities would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations were as follows:


	December 31,
	2021		2020
Shares subject to outstanding common stock options		2,215,942		2,278,771
Shares subject to outstanding restricted stock units		460,000		—
Estimated shares issuable under the employee stock purchase plan		67,253		24,118
Total		2,743,195		2,302,889

Related Party Transactions

12 Months Ended

Dec. 31, 2021

Related Party Transactions

15. Related Party Transactions

In November 2021, Richard King retired and resigned from his positions as the Company’s Chief Executive Officer and member of the Board. In connection with Mr. King’s departure, the Company and Mr. King entered into a separation and release agreement effective as of November 15, 2021, or the Separation Agreement. Pursuant to the Separation Agreement, Mr. King was entitled to receive an amount equal to 12 months of his base salary ($500,000 per year), which was paid in a single lump sum payment in January 2022, and continued coverage under COBRA for 12 months. In addition, the Separation Agreement provided that all vested options held by Mr. King as of the separation date be exercisable through June 30, 2023. The Company recorded stock compensation charges of $90 thousand in connection with extending the option exercise period.

Subsequent Events

12 Months Ended

Dec. 31, 2021

Subsequent Events [Abstract]

Subsequent Events

16. Subsequent Events

Grant of Stock Options and RSUs

In January 2022, the Company granted options to purchase an aggregate of 1,146,500 shares of common stock to employees. In addition, the Company granted RSUs to employees underlying 92,200 shares of common stock.

Shelf Registration and Sales Agreement

In February 2022, the SEC declared effective a registration statement on Form S-3 (No.333-261960), or the Shelf Registration, covering the sale of up to $200.0 million of our securities. Also, in February 2022, the Company entered into an Open Market Sales AgreementSM with Jefferies LLC (Jefferies) pursuant to which the Company may elect to issue and sell, from time to time, shares of common stock having an aggregate offering price of up to $21.0 million under the Shelf Registration through Jefferies acting as the sales agent and/or principal.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Risks and Uncertainties

Segment Reporting

Cash and Cash Equivalents

Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed statements of cash flows (in thousands):


	December 31,
	2021		2020
Cash and cash equivalents	$	42,748	$	157,150
Restricted cash		216		216
Total cash, cash equivalents and restricted cash	$	42,964	$	157,366

Fair Value of Financial Instruments

The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows:

▪

Level 1—Quoted prices in active markets for identical assets and liabilities;

▪

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Property and Equipment, Net

The useful lives of property and equipment are as follows:


Computer and office equipment	3 years
Computer software	3 years
Manufacturing machinery and equipment	7 years
Leasehold improvements	Lesser of lease term or 15 years
Furniture and fixtures	5 years

Concentration of Credit Risk

exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.

Leases

The Company adopted Accounting Standards Update (ASU), No. 2016-02, Leases (Topic 842) effective January 1, 2020.

Research and Development Expenses

Accrued Research and Development Expenses

Income Taxes

Stock-Based Compensation

For equity awards granted to employees, non-employees, and directors, the Company recognizes compensation expense based on the estimated grant-date fair values.

Net Loss per Share

Commitments and Contingencies

Emerging Growth Company Status

Recent Accounting Pronouncements Not Yet Adopted

Recently Adopted Accounting Pronouncements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed statements of cash flows (in thousands):


	December 31,
	2021		2020
Cash and cash equivalents	$	42,748	$	157,150
Restricted cash		216		216
Total cash, cash equivalents and restricted cash	$	42,964	$	157,366

Schedule of Useful Lives of Property and Equipment

The useful lives of property and equipment are as follows:


Computer and office equipment	3 years
Computer software	3 years
Manufacturing machinery and equipment	7 years
Leasehold improvements	Lesser of lease term or 15 years
Furniture and fixtures	5 years

Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Summary Of Amortized Cost, Unrealized Gains, And Losses, And Fair Value

The following table is a summary of amortized cost, unrealized gains and losses, and fair value (in thousands):


		December 31, 2021
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Money market funds		$	38,067	$	—	$	—		$	38,067
	Total cash equivalents		38,067		—		—			38,067
Commercial paper			33,973		—		—			33,973
Corporate bonds			6,285		—		(23	)		6,262
U.S. treasury securities			5,999		—		(13	)		5,986
	Total short-term investments		46,257		—		(36	)		46,221
Corporate bonds			8,470		—		(34	)		8,436
U.S. treasury securities			24,137		—		(114	)		24,023
	Total long-term investments		32,607		—		(148	)		32,459
Total cash equivalents and available for sale securities		$	116,931	$	—	$	(184	)	$	116,747

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Summary of Financial Assets Measured at Fair Value on Recurring Basis

The following table summarizes the Company's financial assets measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


		December 31, 2021
		Total		Level 1		Level 2		Level 3
Money market funds		$	38,067	$	38,067	$	—	$	—
	Total cash equivalents		38,067		38,067		—		—
Commercial paper			33,973		—		33,973		—
Corporate bonds			6,262		6,262				—
U.S. treasury securities			5,986		5,986		—		—
	Total short-term investments		46,221		12,248		33,973		—
Corporate bonds			8,436		8,436		—		—
U.S. treasury securities			24,023		24,023		—		—
	Total long-term investments		32,459		32,459		—		—
Total cash equivalents, short-term investments and long-term investments		$	116,747	$	82,774	$	33,973	$	-

Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2021

Balance Sheet Components Disclosure [Abstract]

Schedule of Property and Equipment, Net

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


	December 31,
	2021			2020
Computer and office equipment	$	15		$	3
Computer software		27			10
Manufacturing machinery and equipment		58			4
Leasehold improvements		7			7
Furniture and fixtures		64			57
Less: accumulated depreciation		(31	)		(8	)
Property and equipment, net	$	140		$	73

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31,
	2021		2020
Accrued research and development expenses	$	3,837	$	2,002
Accrued general and administrative expenses		416		245
Lease liability, current portion		360		249
Total accrued expenses and other current liabilities	$	4,613	$	2,496

Leases (Tables)

12 Months Ended

Dec. 31, 2021

Leases [Abstract]

Future Minimum Annual Lease Commitments under Non-cancelable Operating Leases

Future minimum annual lease commitments under the Company’s non-cancelable operating leases as of December 31, 2021 were as follows (in thousands):


	Amount
2022	$	464
2023		478
2024		493
2025		464
2026		—
Total undiscounted future minimum lease payments		1,899
Less: present value discount		(246	)
Total discounted future minimum lease payments	$	1,653
Lease liability, current portion (included in "accrued expenses and other current liabilities" on the condensed balance sheet)	$	360
Lease liability, net of current portion		1,293
Total operating lease liability	$	1,653

Term Loan (Tables)

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Schedule of Term Loan

The Term Loan and unamortized discount and debt issuance costs balances as of December 31, 2021 are shown below (in thousands):


	December 31, 2021			December 31, 2020
Total Term Loan debt	$	5,000		$	4,500
Less: unamortized discount and debt issuance costs		(122	)		(24	)
Total Term Loan, net		4,878			4,476
Less: Term Loan, current portion		—			(2,554	)
Term loan, net of current portion	$	4,878		$	1,922

Schedule of Future Principal Payments

As of December 31, 2021, future principal payments per year under the Term Loan were as follows (in thousands):


	Amount
2022	$	—
2023		1,622
2024		1,622
2025		1,621
2026		135
Total	$	5,000

Capital Structure (Tables)

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance, on an as converted basis, consisted of the following:


	December 31,
	2021		2020
Stock options, issued and outstanding		2,215,942		2,278,771
Restricted and performance stock units, issued and outstanding		460,000		—
Shares available for future issuance under 2020 Equity Incentive Plan		2,636,506		2,637,076
Employee stock purchase plan, available for future issuance		433,200		220,640
Total shares reserved		5,745,648		5,136,487

Equity Incentive Plan and Stock-Based Compensation Expense (Tables)

12 Months Ended

Dec. 31, 2021

Summary of Stock Option Activity

A summary of the Company’s stock option activity and related information is as follows (in thousands, except share and per share amounts):


	Outstanding Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Balance as of December 31, 2019		859,322		$	1.20		7.9	$	209
Granted		1,775,808			3.33		—		—
Exercised		(57,614	)		0.89		—		—
Forfeited/Cancelled		(298,745	)		1.86		—		—
Balance as of December 31, 2020		2,278,771			2.78		8.6	$	49,059
Granted		947,917			10.78		—		—
Exercised		(211,439	)		1.55		—		—
Forfeited/Cancelled		(799,307	)		7.30		—		—
Balance as of December 31, 2021		2,215,942		$	4.72		6.9	$	3,959
Vested and expected to vest as of December 31, 2021		2,181,939		$	4.72		6.9	$	3,959
Vested and exercisable as of December 31, 2021		961,313		$	3.54		3.9	$	2,209

Schedule of Weighted-Average Assumptions to Estimate Fair Value Using Black-Scholes Option-Pricing Model

the following weighted-average assumptions:


	2021			2020
Expected term (in years)		6.0			6.0
Expected volatility		102.8	%		80.1	%
Risk-free interest rate		0.9	%		0.4	%
Expected dividend rate		0.0	%		0.0	%

Summary of RSU Activity

A summary of the Company’s RSU activity and related information is as follows (in thousands, except share and per share amounts):


	RSUs
	Shares		Weight-Average Grant Date Fair Value Per Share
Unvested balance as of December 31, 2020		—	$	—
Granted		460,000		2.48
Vested		—		—
Forfeited		—		—
Unvested balance as of December 31, 2021		460,000	$	2.48

Summary of Stock-Based Compensation Expense


	Year Ended December 31,
	2021		2020
Research and development	$	1,045	$	327
General and administrative		2,913		428
Total stock-based compensation expense	$	3,958	$	755

2020 Employee Stock Purchase Plan

Schedule of Weighted-Average Assumptions to Estimate Fair Value Using Black-Scholes Option-Pricing Model

the following weighted-average assumptions:


	2021			2020
Expected term (in years)		6.0			6.0
Expected volatility		102.8	%		80.1	%
Risk-free interest rate		0.9	%		0.4	%
Expected dividend rate		0.0	%		0.0	%

Schedule of Assumptions Used to Calculate Stock Based Compensation Each Stock Purchase Right Granted Under ESPP

The following assumptions were used to calculate stock-based compensation for each stock purchase right granted under the ESPP:


	2021			2020
Expected term (in years)		1.4			1.5
Expected volatility		78.7	%		90.8	%
Risk-free interest rate		0.1	%		0.2	%
Expected dividend rate		0.0	%		0.0	%

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Reconciliation of the Federal Statutory Income Tax Rate to Effective Tax Rate

The reconciliation of the federal statutory income tax rate to the Company’s effective tax rate is as follows:


	December 31,
	2021				2020
Federal statutory tax rate		21.00		%		21.00		%
State tax, net of federal benefit		6.98		%		6.98		%
Nondeductible expenses		(0.38	)	%		(0.09	)	%
Tax credits		5.31		%		6.15		%
Change in valuation allowance		(32.96	)	%		(41.38	)	%
Prior year true-up for state net operating losses		-		%		6.96		%
Other		0.05		%		0.38		%
Effective tax rate		0		%		0		%

Schedule of Significant Components of Net Deferred Tax Assets and Liabilities

Significant components of the Company’s net deferred tax assets and liabilities are as follows (in thousands):


	December 31,
	2021			2020
Deferred tax assets:
Net operating loss carryforwards	$	27,570		$	16,381
Accruals		99			326
Intangible assets		131			143
Tax credits		4,766			2,500
Lease liability		463
Other		785			109
Total gross deferred tax assets		33,814			19,459
Valuation allowance for deferred tax assets		(33,397	)		(19,459	)
Deferred tax liabilities:
Right-of-use assets		(414	)		—
Other		(3	)		—
Total deferred tax liabilities		(417	)		—
Total net deferred tax assets	$	—		$	—

Schedule of Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits

A reconciliation of the beginning and ending balance of the unrecognized tax benefits is as follows (in thousands):


	December 31,
	2021			2020
Balance at the beginning of the year	$	1,094		$	398
Increase of unrecognized tax benefits taken in prior years		-			10
Decrease of unrecognized tax benefits taken in prior years		(198	)		-
Increase of unrecognized tax benefits related to current year		693			686
Balance at the end of the year	$	1,589		$	1,094

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Net Loss Per Share

The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share amounts):


	Year Ended December 31,
	2021			2020
Numerator:
Net loss	$	(42,292	)	$	(29,539	)
Denominator:
Weighted-average common shares outstanding		23,361,416			5,991,213
Net loss per share, basic and diluted	$	(1.81	)	$	(4.93	)

Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share


	December 31,
	2021		2020
Shares subject to outstanding common stock options		2,215,942		2,278,771
Shares subject to outstanding restricted stock units		460,000		—
Estimated shares issuable under the employee stock purchase plan		67,253		24,118
Total		2,743,195		2,302,889

Organization and Principal Activities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Aug. 31, 2020	Feb. 29, 2020	Oct. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Organization And Principal Activities [Line Items]
Net loss				$ (42,292)	$ (29,539)
Cash in operations				35,900
Accumulated deficit				(103,133)	(60,841)
Cash, cash equivalents and investments				$ 121,400
Redeemable Convertible Preferred Stock
Organization And Principal Activities [Line Items]
Redeemable convertible preferred stock converted into common stock			15,492,019
Series B Redeemable Convertible Preferred Stock
Organization And Principal Activities [Line Items]
Redeemable convertible preferred stock, shares issued	36,666,665	36,666,665
Proceeds from issuance of Series B redeemable convertible preferred stock, net of issuance costs	$ 44,000	$ 43,600			$ 87,633
Initial Public Offering
Organization And Principal Activities [Line Items]
Offering price			$ 15.00
Net proceeds of common stock			$ 93,400
Initial Public Offering \| Common Stock
Organization And Principal Activities [Line Items]
Initial public offering of common stock			6,900,000		6,900,000
Overallotment Option \| Common Stock
Organization And Principal Activities [Line Items]
Initial public offering of common stock			900,000

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) Segment
Summary Of Significant Accounting Policies [Line Items]
Number of operating segment \| Segment	1
Interest or penalties charged related to unrecognized tax benefits \| $	$ 0
Recognition of stock option awards over requisite service period	4 years
Topic 842
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020
Topic 740
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
Stock Option
Summary Of Significant Accounting Policies [Line Items]
Recognition of stock option awards over requisite service period	4 years

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 42,748	$ 157,150
Restricted cash	216	216
Total cash, cash equivalents and restricted cash	$ 42,964	$ 157,366

Summary of Significant Accounting Policies - Schedule of Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Computer and Office Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	3 years
Computer Software
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	3 years
Manufacturing Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	7 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	Lesser of lease term or 15 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, useful Lives	5 years

Cash Equivalents And Investments - Summary Of Amortized Cost, Unrealized Gains, And Losses, And Fair Value (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents and available for sale securities, amortized cost	$ 116,931
Cash and cash equivalents and available for sale securities, gross unrealized losses	(184)
Total cash equivalents, short term investments and long term investments	116,747
Short Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	46,257
Available for sale, gross unrealized losses	(36)
Available for sale, fair value	46,221
Long Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	32,607
Available for sale, gross unrealized losses	(148)
Available for sale, fair value	32,459
Money Market Funds
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, amortized cost	38,067
Cash and cash equivalents, fair value	38,067
Cash And Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Cash and cash equivalents, amortized cost	38,067
Cash and cash equivalents, fair value	38,067
Commercial Paper \| Short Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	33,973
Available for sale, fair value	33,973
Corporate Bond \| Short Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	6,285
Available for sale, gross unrealized losses	(23)
Available for sale, fair value	6,262
Corporate Bond \| Long Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	8,470
Available for sale, gross unrealized losses	(34)
Available for sale, fair value	8,436
US Treasury Securities \| Short Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	5,999
Available for sale, gross unrealized losses	(13)
Available for sale, fair value	5,986
US Treasury Securities \| Long Term Investments
Debt Securities, Available-for-sale [Line Items]
Available for sale, amortized cost	24,137
Available for sale, gross unrealized losses	(114)
Available for sale, fair value	$ 24,023

Cash Equivalents And Investments - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021 USD ($)
Investments, Debt and Equity Securities [Abstract]
Weighted-average remaining contractual term maturities available for sale	11 months
Debt securities, available-for-sale, realized gain (loss)	$ 0
Debt securities, available-for-sale, Continuous unrealized loss position, 12 months or longer	0
Debt securities, available-for-sale, realized gain (loss), excluding other-than-temporary impairment	$ 0
Cash equivalents and short term investments due term	1 year

Fair Value Measurements - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated fair value of term loan	$ 5,000,000.0
Fair Value Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities fair value	$ 0
Fair Value Non-recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities fair value		$ 0

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation	$ (31)	$ (8)
Property and equipment, net	140	73
Computer and Office Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	15	3
Computer Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27	10
Manufacturing Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	58	4
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7	7
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 64	$ 57

Balance Sheet Components (Additional Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Components Disclosure [Abstract]
Depreciation expense	$ 23	$ 5

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Components Disclosure [Abstract]
Accrued research and development expenses	$ 3,837	$ 2,002
Accrued general and administrative expenses	416	245
Lease liability, current portion	360	249
Total accrued expenses and other current liabilities	$ 4,613	$ 2,496

Leases - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 29, 2020	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease commencement date	2020-09
Operating lease term	63 months
Operating leases, gross commitment	$ 2,300
Operating Leases, option to renew lease term description		The lease includes an option to renew the lease term for an additional period of 60 months. The renewal option is not included in the lease term or minimum lease payments disclosures below as the Company is not reasonably certain to exercise the option.
Operating Leases, option to renew lease term	true
Operating leases, renew lease term	60 months
Operating leases, lease expense		$ 400	$ 100
Weighted-average remaining lease term for operating leases		3 years 10 months 24 days
weighted-average discount rate		7.00%
Cash paid for amounts included in measurement of lease liabilities		$ 300	$ 37

Leases - Future Minimum Annual Lease Commitments under Non-cancelable Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2022	$ 464
2023	478
2024	493
2025	464
Total undiscounted future minimum lease payments	1,899
Less: present value discount	(246)
Total discounted future minimum lease payments	1,653
Lease liability, current portion (included in "accrued expenses and other current liabilities" on the condensed balance sheet)	$ 360	$ 249
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Lease liability, net of current portion	$ 1,293	$ 1,653

Term Loan - Additional Information (Details)	1 Months Ended			12 Months Ended
Term Loan - Additional Information (Details)	Nov. 30, 2020 shares	Apr. 30, 2020	Sep. 30, 2019 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) Installment	Dec. 31, 2020 USD ($)	Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Aggregate principal amount				$ 4,878,000	$ 4,476,000
Term Loan
Debt Instrument [Line Items]
Debt instrument, extended term		6 months
Aggregate principal amount				$ 30,000,000.0
Debt instrument, maturity date				Jan. 01, 2026
Debt Instrument Frequency Of Periodic Payment				monthly
Number of Monthly Installments \| Installment				37
End of term payment, percentage				9.50%
Debt issuance costs				$ 10,000.0
Unamortized debt issuance costs and debt discount				100,000
Unamortized debt discount				16,000.0
Interest payments on debt				200,000	$ 200,000
Term Loan \| The First Amendment
Debt Instrument [Line Items]
Debt issuance costs				$ 2,000.0
Term Loan \| Maximum
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage				3.00%
Term Loan \| Minimum
Debt Instrument [Line Items]
Debt instrument prepayment fee percentage				1.00%
Term Loan \| Common Stock \| Warrant
Debt Instrument [Line Items]
Number of shares issuable upon the exercise of warrant \| shares			49,609
Warrants exercise price \| $ / shares			$ 1.44
Estimated fair value of the warrant			$ 100,000
Net exercised of common stock \| shares	46,358
First Tranche Term Loan
Debt Instrument [Line Items]
Aggregate principal amount				$ 15,000,000.0		$ 20,000,000.0
Repayment of outstanding obligations				$ 5,000,000.0
Debt instrument, maturity date				Dec. 31, 2021
End of term payment, percentage				6.00%
Second Tranche Term Loan
Debt Instrument [Line Items]
Aggregate principal amount				$ 10,000,000.0
Debt instrument, maturity date				Dec. 31, 2022
Floating interest rate scenario one				4.25%
Debt instrument basis spread variable rate scenario two				6.25%
Number of Monthly Installments \| Installment				25
Second Tranche Term Loan \| Prime Rate \| Maximum
Debt Instrument [Line Items]
Debt instrument basis spread variable rate scenario one				1.00%
Debt instrument basis spread variable rate scenario two				3.00%

Term Loan - Schedule of Term Loan (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Total Term Loan debt	$ 5,000	$ 4,500
Less: unamortized discount and debt issuance costs	(122)	(24)
Total Term Loan, net	4,878	4,476
Less: Term Loan, current portion		(2,554)
Term loan, net of current portion	$ 4,878	$ 1,922

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References + Details

Term Loan - Schedule of Future Principal Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2023	$ 1,622
2024	1,622
2025	1,621
2026	135
Total	$ 5,000	$ 4,500

Capital Structure - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Oct. 31, 2020
Class Of Stock [Line Items]
Common stock shares authorized	200,000,000	200,000,000
Common stock par value	$ 0.0001	$ 0.0001
Common stockholders voting rights	one vote
Common stock dividends declared	$ 0
Redeemable Convertible Preferred Stock
Class Of Stock [Line Items]
Redeemable convertible preferred stock converted into common stock			15,492,019
Redeemable convertible preferred stock, shares outstanding	0	0

Capital Structure - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Shares reserved for future issuance	5,745,648	5,136,487
Employee Stock Purchase Plan, Available for Future Issuance
Class Of Stock [Line Items]
Shares reserved for future issuance	433,200	220,640
Stock Options, Issued and Outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	2,215,942	2,278,771
Shares available for future issuance under 2020 Equity Incentive Plan
Class Of Stock [Line Items]
Shares reserved for future issuance	2,636,506	2,637,076
Restricted and performance stock units, issued and outstanding
Class Of Stock [Line Items]
Shares reserved for future issuance	460,000

Equity Incentive Plan and Stock-Based Compensation Expense - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Dec. 31, 2021	Oct. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance	5,745,648		5,745,648	5,136,487
Equity incentive plans terms			Following the effectiveness of the 2020 Plan, no further grants will be made under the 2016 Plan; however, shares subject to awards granted under the 2016 Plan will continue to be governed by the 2016 Plan.
Number of shares early exercised under any plan	0		0
Aggregate intrinsic value of options exercised			$ 2,000	$ 300
Requisite service period of award			4 years
Options granted to purchase shares of common stock			947,917	1,775,808
Options granted to purchase shares of common stock, weighted-average exercise price			$ 10.78	$ 3.33
Weighted-average fair value of options granted			$ 8.55	$ 3.56
Compensation expense			$ 3,958	$ 755
Unrecognized stock-based compensation expense	$ 5,700		$ 5,700
Unrecognized stock-based compensation expense expected to be recognized over weighted-average vesting term			2 years 9 months 18 days
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of modified awards to be recognized over requisite service period	$ 2,400		$ 2,400
Compensation expense			$ 900
Performance Stock Options \| Stock Option Granted to Executive Officers
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options granted to purchase shares of common stock			127,042
RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted	460,000		460,000
Unrecognized stock-based compensation expense	$ 800		$ 800
Unrecognized stock-based compensation expense expected to be recognized over weighted-average vesting term			1 year 3 months 18 days
Time Based Vesting Installments Through June 30, 2023 \| RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted	230,000
Performance Based Vesting \| RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs granted	230,000
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance		2,647,684
Term of automatically increase in common stock available for issuance		10 years
Percentage of outstanding shares subject to automatic increase in common stock		5.00%
Equity incentive plans terms		In addition, the number of shares of common stock available for issuance under the 2020 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2020 Plan, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year or such lesser amount as determined by the Company’s Board of Directors.
Incentive stock options granted description			Under the Plan, the Board of Directors determines the per share exercise price of each stock option, which for ISOs shall not be less than 100% of the fair market value of a share on the date of grant; provided that the exercise price of an ISO granted to a stockholder who at the time of grant owns stock representing more than 10% of the voting power of all classes of stock (a 10% stockholder) shall not be less than 110% of the fair market value of a share on the date of grant.
Vesting period			4 years
Equity incentive plan, maximum term			5 years
Options termination term, if option holders service terminate			3 months
Options granted to purchase shares of common stock			947,917	1,775,808
Number of options exercised			211,439	57,614
Shares authorized for issuance	3,810,703		3,810,703
Shares remained available for issuance	2,636,506		2,636,506
Options granted to purchase shares of common stock, weighted-average exercise price			$ 10.78	$ 3.33
2020 Equity Incentive Plan \| All Other Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity incentive plan, maximum term			10 years
2020 Equity Incentive Plan \| First Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage			25.00%
2020 Equity Incentive Plan \| Monthly Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage			2.083%
2020 Equity Incentive Plan \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of incentive stock options granted			100.00%
Percentage of Exercise price of incentive stock options granted owns stock			10.00%
Fair market value exercise price percentage			110.00%
2016 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares authorized for issuance	1,501,745		1,501,745
Shares remained available for issuance	0		0
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance		220,640
Term of automatically increase in common stock available for issuance		10 years
Percentage of outstanding shares subject to automatic increase in common stock		1.00%
Equity incentive plans terms			In addition, the number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten-years of the term of the ESPP, beginning with January 1, 2021 and ending with January 1, 2030, by an amount equal to the lessor of (i) 1% of the outstanding number of shares of the Company’s common stock on December 31st of the preceding calendar year, (ii) 441,280 shares of common stock or (iii) such lesser amount as determined by the Board of Directors.
Shares remained available for issuance	433,200	441,280	433,200
Requisite service period of award			2 years
ESPP issued			20,043
Maximum percentage of compensation that an employee is allowed to purchase shares		15.00%
Purchase price of common stock expressed as a percentage of fair market value		85.00%
Employee stock purchase plan offering period			provides for 24-month offering periods starting every January 1st and July 1st, each consisting of four six-month purchase periods
Compensation expense			$ 100	$ 32

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted, Weighted-Average Exercise Price	$ 10.78	$ 3.33
2020 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning Balance, Outstanding Stock Options	2,278,771	859,322
Granted, Outstanding Stock Options	947,917	1,775,808
Exercised, Outstanding Stock Options	(211,439)	(57,614)
Forfeited/Cancelled, Outstanding Stock Options	(799,307)	(298,745)
Ending Balance, Outstanding Stock Options	2,215,942	2,278,771	859,322
Vested and expected to vest, Outstanding Stock Options	2,181,939
Vested and exercisable, Outstanding Stock Options	961,313
Beginning Balance, Weighted-Average Exercise Price	$ 2.78	$ 1.20
Granted, Weighted-Average Exercise Price	10.78	3.33
Exercised, Weighted-Average Exercise Price	1.55	0.89
Forfeited/Cancelled, Weighted-Average Exercise Price	7.30	1.86
Ending Balance, Weighted-Average Exercise Price	4.72	$ 2.78	$ 1.20
Vested and expected to vest, Weighted-Average Exercise Price	4.72
Vested and exercisable, Weighted-Average Exercise Price	$ 3.54
Weighted-Average Remaining Contractual Life (Years)	6 years 10 months 24 days	8 years 7 months 6 days	7 years 10 months 24 days
Vested and expected to vest, Weighted-Average Remaining Contractual Life (Years)	6 years 10 months 24 days
Vested and exercisable, Weighted-Average Remaining Contractual Life (Years)	3 years 10 months 24 days
Aggregate Intrinsic Value	$ 3,959	$ 49,059	$ 209
Vested and expected to vest, Aggregate Intrinsic Value	3,959
Vested and exercisable, Aggregate Intrinsic Value	$ 2,209

Equity Incentive Plan and Stock-Based Compensation Expense - Schedule of Weighted-Average Assumptions to Estimate Fair Value Using Black-Scholes Option-Pricing Model (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years	6 years
Expected volatility	102.80%	80.10%
Risk-free interest rate	0.90%	0.40%
Expected dividend rate	0.00%	0.00%
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	1 year 4 months 24 days	1 year 6 months
Expected volatility	78.70%	90.80%
Risk-free interest rate	0.10%	0.20%
Expected dividend rate	0.00%	0.00%

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of RSU Activity (Details) - RSU - $ / shares	1 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Granted	460,000	460,000
Shares, Unvested, Ending Balance	460,000	460,000
Weighted Average Grant Date Fair Value Per Share, Granted		$ 2.48
Weighted Average Grant Date Fair Value Per Share, Ending Balance	$ 2.4	$ 2.4

Equity Incentive Plan and Stock-Based Compensation Expense - Schedule of Assumptions Used to Calculate Stock Based Compensation Each Stock Purchase Right Granted Under ESPP (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years	6 years
Expected volatility	102.80%	80.10%
Risk-free interest rate	0.90%	0.40%
Expected dividend rate	0.00%	0.00%
2020 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	1 year 4 months 24 days	1 year 6 months
Expected volatility	78.70%	90.80%
Risk-free interest rate	0.10%	0.20%
Expected dividend rate	0.00%	0.00%

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,958	$ 755
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,045	327
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 2,913	$ 428

License Agreement - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2016
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense	$ 30,698,000	$ 23,854,000
License Agreement \| Eli Lilly and Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development expense			$ 800,000
Milestone payments due	23,000,000.0
Research and development arrangement, costs incurred	$ 0	$ 0

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Income tax expense	$ 0	$ 0
Increase in net valuation allowance	13,900,000	12,200,000
Unrecognized tax benefits	1,589,000	1,094,000	$ 398,000
Income tax penalties or interest	$ 0	0
Maximum
Income Tax Disclosure [Line Items]
Percentage of tax positions likely of being realized upon ultimate settlement	50.00%
Federal
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 98,600,000			$ 91,400,000
Net operating loss carryforwards expiration year	2036
Federal \| Research Credit Carry Forwards
Income Tax Disclosure [Line Items]
Tax credit carryforward, amount	$ 5,600,000
Tax credit carryforward expiration year	2036
Gross federal tax credit-related deferred tax assets derecognized		$ 2,000
State
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 98,400,000
Net operating loss carryforwards expiration year	2036
State \| Research Credit Carry Forwards
Income Tax Disclosure [Line Items]
Tax credit carryforward, amount	$ 1,000,000.0

Income Taxes - Schedule of Reconciliation of the Federal Statutory Income Tax Rate to Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory tax rate	21.00%	21.00%
State tax, net of federal benefit	6.98%	6.98%
Nondeductible expenses	(0.38%)	(0.09%)
Tax credits	5.31%	6.15%
Change in valuation allowance	(32.96%)	(41.38%)
Prior year true-up for state net operating losses		6.96%
Other	0.05%	0.38%
Effective tax rate	0.00%	0.00%

Income Taxes - Schedule of Significant Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 27,570	$ 16,381
Accruals	99	326
Intangible assets	131	143
Tax credits	4,766	2,500
Lease liability	463
Other	785	109
Total gross deferred tax assets	33,814	19,459
Valuation allowance for deferred tax assets	(33,397)	$ (19,459)
Deferred tax liabilities:
Right-of-use assets	(414)
Other	(3)
Total deferred tax liabilities	$ (417)

Income Taxes - Schedule of Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Balance at the beginning of the year	$ 1,094	$ 398
Increase of unrecognized tax benefits taken in prior years		10
Decrease of unrecognized tax benefits taken in prior years	(198)
Increase of unrecognized tax benefits related to current year	693	686
Balance at the end of the year	$ 1,589	$ 1,094

401(k) Retirement Savings Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
401(K) Plan
Defined Benefit Plan Disclosure [Line Items]
Matching employer contributions	$ 0	$ 0

Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (42,292)	$ (29,539)
Denominator:
Weighted-average common shares outstanding	23,361,416	5,991,213
Net loss per share, basic and diluted	$ (1.81)	$ (4.93)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 60B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580

Reference 25: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8924-108599

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599

+ Details

Net Loss Per Share - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	2,743,195	2,302,889
Shares Subject to Outstanding Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	2,215,942	2,278,771
Shares subject to outstanding restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	460,000
Estimated Shares Issuable Under Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share	67,253	24,118

Related Party Transactions - Additional Information (Details) - Separation Agreement - Mr. King - USD ($) $ in Thousands		12 Months Ended
	Nov. 15, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Separation Agreement term		Pursuant to the Separation Agreement, Mr. King was entitled to receive an amount equal to 12 months of his base salary ($500,000 per year), which was paid in a single lump sum payment in January 2022, and continued coverage under COBRA for 12 months. In addition, the Separation Agreement provided that all vested options held by Mr. King as of the separation date be exercisable through June 30, 2023.
Base salary	$ 500,000
Separation Agreement completion date	Jun. 30, 2023
Stock compensation charges	$ 90

Subsequent Events - Additional Information (Details) - Subsequent Event - USD ($) $ in Millions	Jan. 31, 2022	Feb. 28, 2022
Subsequent Event [Line Items]
Options granted to purchase shares of common stock	1,146,500
Shelf Registration and Sales Agreement
Subsequent Event [Line Items]
Maximum amount of sale covered in shelf registration statement		$ 200.0
Maximum amount of offering issuance and sale covered in sales agreement		$ 21.0
RSU
Subsequent Event [Line Items]
RSU Granted	92,200

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents, short term investments and long term investments	$ 116,747
Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	46,221
Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	32,459
Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, fair value	38,067
Commercial Paper \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	33,973
Corporate Bond \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	6,262
Corporate Bond \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	8,436
US Treasury Securities \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	5,986
US Treasury Securities \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	24,023
Fair Value Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, fair value	38,067
Total cash equivalents, short term investments and long term investments	116,747
Fair Value Recurring \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	46,221
Fair Value Recurring \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	32,459
Fair Value Recurring \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, fair value	38,067
Total cash equivalents, short term investments and long term investments	82,774
Fair Value Recurring \| Level 1 \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	12,248
Fair Value Recurring \| Level 1 \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	32,459
Fair Value Recurring \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents, short term investments and long term investments	33,973
Fair Value Recurring \| Level 2 \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	33,973
Fair Value Recurring \| Money Market Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, fair value	38,067
Fair Value Recurring \| Money Market Funds \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents, fair value	38,067
Fair Value Recurring \| Commercial Paper \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	33,973
Fair Value Recurring \| Commercial Paper \| Level 2 \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	33,973
Fair Value Recurring \| Corporate Bond \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	6,262
Fair Value Recurring \| Corporate Bond \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	8,436
Fair Value Recurring \| Corporate Bond \| Level 1 \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	6,262
Fair Value Recurring \| Corporate Bond \| Level 1 \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	8,436
Fair Value Recurring \| US Treasury Securities \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	5,986
Fair Value Recurring \| US Treasury Securities \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	24,023
Fair Value Recurring \| US Treasury Securities \| Level 1 \| Short Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	5,986
Fair Value Recurring \| US Treasury Securities \| Level 1 \| Long Term Investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale, fair value	$ 24,023