0001746473-23-000008 | 10-K | XBRL Viewer

Common Stock

12 Months Ended

Dec. 31, 2022

As of December 31, 2022 and 2021, the Company had 300,000,000 authorized shares of common stock, at a par value of $0.0001 per share. The common stock has the following rights and privileges:

Voting

The holders of shares of common stock are entitled to one vote for each share of common stock held at any meeting of stockholders and at the time of any written action in lieu of a meeting.

Dividends

The holders of shares of common stock are entitled to receive dividends, when declared by the Company’s Board of Directors. Cash dividends may not be declared or paid to holders of shares of common stock until all unpaid dividends on the Preferred Stock have been paid in accordance with their terms. No dividends have been declared or paid by the Company since its inception.

Liquidation

The holders of shares of common stock are entitled to share ratably in the Company’s remaining assets available for distribution to its stockholders in the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or upon occurrence of a deemed liquidation event.

Shares reserved for future issuance


	December 31,
	2022	2021
Outstanding stock option awards	5,569,567	3,620,180
Vesting of RSUs	507,925	—
Vesting of PSUs*	531,796	—
Shares of common stock available for future grants under the 2020 Stock Option and Incentive Plan	2,937,769	4,234,213
Shares of common stock available for future issuance under the 2020 Employee Stock Purchase Plan	888,184	613,098
Shares of common stock available for future issuance under the 2022 Inducement Plan	1,000,000	—
Total shares reserved for future issuance	11,435,241	8,467,491
*PSUs granted and outstanding based on target level of achievement of 100%.

- 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

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+ Details

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Basis of Presentation

The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Certain prior year reported amounts have been reclassified to conform with the current period presentation.

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 the disclosure of contingent assets and liabilities in the financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, accruals for research and development costs, fair value of assets, stock-based compensation, income taxes and uncertain tax positions. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances, however, actual results may differ from those estimates.

Revenue Recognition

The Company accounts for revenues in accordance with Accounting Standards Codification Topic 606, Revenue from Contracts with Customers (Topic 606). To determine revenue recognition for arrangements that fall within the scope of ASC 606, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy a performance obligation. We only apply the five-step model to contracts when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services we transfer to the customer.

At contract inception, we assess the goods or services promised within each contract, determine those that are performance obligations, and assess whether each promised good or service is distinct. We then recognize as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. To date, our revenues have been generated solely from the Collaboration and License Agreement with Novartis (the “Novartis Agreement”). The Novartis Agreement includes licenses of intellectual property, cost reimbursements, research and development services, upfront signing fees, milestone payments and royalties on future licensee’s product sales.

As part of accounting for this arrangement, we must apply judgment to determine whether the performance obligations are distinct, and develop assumptions in determining the stand-alone selling price for each distinct performance obligation identified in the contract. To determine the stand-alone selling price, we rely on assumptions which may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success.

Licenses of Intellectual Property

If the license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, we utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenues. We evaluate the measure of progress each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.

Milestone Payments

At the inception of an arrangement that includes development milestone payments, we evaluate whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which we recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each reporting period, we re-evaluate the probability of achievement of such development milestones and any related constraint and, if necessary, adjust our estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaboration and license revenue in the period of adjustment.

Research and development services

Amounts related to research and development services are recognized as the related services or activities are performed, in accordance with the contract terms. The cost associated with full-time equivalent researchers is estimated each period and billable to Novartis based at specified full-time equivalent rates.

Royalties:

The sales-based royalties, including milestone payments based on the level of sales, are considered to be predominately related to the license included in the arrangement, and we will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, we have not recognized any royalty revenue from the Novartis Agreement.

We recognize contract assets when we have a right to consideration in exchange for goods or services that the Company has transferred to a customer when that right is conditional on something other than the passage of time. A receivable will be recorded on the balance sheet when the Company has unconditional rights to consideration (i.e., only the passage of time is required before payment becomes due). A contract liability is an obligation to transfer goods or services for which the Company has received consideration, or for which an amount of consideration is due from the customer. Receivables cannot be netted against contract liabilities and would be presented separately from contract assets. Contract assets and contract liabilities are netted at the contract level.

Fair Value Measurements

The Company defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities which are required to be recorded at fair value, the Company considers the principal or most advantageous market in which to transact and the market-based risk. Fair value accounting is applied for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. The carrying amount of the Company’s financial instruments, including cash and cash equivalents, tax credit receivable, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their short-term maturities.

Concentration of Credit Risk and Other Risks and Uncertainties Policy

Concentration of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents, short-term investments and accounts receivable. The Company invests in money market funds, U.S. Treasury securities, government notes and corporate debt securities. The Company limits its credit risk associated with its cash and cash equivalents by placing them with banks and institutions it believes are highly credit worthy and in highly rated investments. However, the Company had deposits in excess of the Federal Deposit Insurance Corporation (“FDIC”) insured limit of $250,000. The Company performs credit evaluations of its customer, and the risk with respect to accounts receivable is further mitigated by the short duration of customer payment terms, generally within 60 days, and the pedigree

of the customer base. During the years ended December 31, 2022 and 2021, Novartis accounted for 100% of the Company’s revenue and accounts receivable.

The Company’s future results of operations involve several other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s product candidates, uncertainty of market acceptance of the Company’s product candidates, competition from substitute products, including those that may be developed or marketed by larger companies, securing and protecting intellectual property, strategic relationships and dependence on key individuals and sole source suppliers.

The Company’s product candidates require approvals from the U.S. Food and Drug Administration (“FDA”) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

Segments

The Company operates and manages its business as one reportable and operating segment, which is the business of developing and commercializing novel therapies for fibrotic diseases. 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 purchased with original maturities of three months or less from the purchase date to be cash equivalents. Cash equivalents consist primarily of amounts invested in Money Market Funds, United States (“U.S.”) treasury securities, U.S. government agency securities and corporate debt securities and are stated at fair value.

Short-Term Investments

The Company’s short-term investments consist of U.S. Treasury securities, U.S. government agency securities and corporate debt securities with remaining maturities beyond three months at the date of purchase. The Company has classified and accounted for its short-term investments as available-for-sale securities as the Company may sell these securities at any time even prior to maturity and such investments represent cash available for current operations. As a result, short-term investments may include securities with maturities beyond twelve months that are classified within current assets in the Balance Sheets. As of December 31, 2022 and 2021, all of the Company’s short-term investments were classified as available-for-sale and were carried at fair market value with unrealized losses recorded in other comprehensive loss in the statements of operations and comprehensive loss. See Note 3 for further details.

Short-term investments are considered impaired when a decline in fair value is judged to be other-than-temporary. The Company consults with its investment managers and considers available quantitative and qualitative evidence in evaluating potential impairment of its short-term investments on a quarterly basis. If the cost of an individual investment exceeds its fair value, the Company evaluates, among other factors, general market conditions, the duration and extent to which the fair value is less than cost and its intent and ability to hold the investment. Once a decline in fair value is determined to be other-than-temporary, an impairment charge will be recorded to other expense, net, in the statements of operations and comprehensive loss and a new cost basis in the short-term investment will be established. As of December 31, 2022, the Company had not recorded any impairment related to other-than-temporary declines in the fair value of short-term investments and long lived assets.

The Company records an allowance for credit losses using an expected loss model. Credit losses are limited to the amount by which the amortized cost of an investment exceeds its fair value. A previously recognized credit loss may be decreased in subsequent periods if the Company’s estimate of fair value for the investment increases. To determine whether to record a credit loss, the Company considers issuer specific credit ratings and historical losses as well as current economic conditions and its expectations for future economic conditions.

Interest and other income

Interest and other income includes interest income from our short-term investment portfolio.

Property and Equipment, Net

Property and equipment are recorded at cost net of accumulated depreciation and amortization. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. The useful lives of property and equipment are as follows:


Laboratory equipment			5 years
Computer equipment and software			3 years
Leasehold improvements			Shorter of remaining lease term or estimated useful life

Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the balance sheets and the resulting gain or loss is recorded to the statements of operations and comprehensive loss. Repairs and maintenance are expensed as incurred.

Leases and Rent Expense

Leases

The Company determines if an arrangement contains a lease at the inception of the contract and a records right-of-use (“ROU”) asset and lease liability on the balance sheet at lease commencement based on the present value of remaining lease payments over the lease term. The Company only considers payments that are fixed and determinable at the time of commencement.

For leases with an initial term greater than 12 months, lease liabilities are recognized based on the present value of the future minimum lease payments discounted by the Company’s estimated incremental borrowing rate. The Company measures ROU assets based on the corresponding lease liability adjusted for (i) payments made to the lessor at or before the commencement date, (ii) initial direct costs incurred and (iii) tenant incentives under the lease. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that it will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

The Company calculates the present value of future minimum lease payments using its estimated incremental borrowing rate when the discount rate implicit in the lease is not known. The incremental borrowing rate is the rate of interest that a lessee would have to pay to borrow on a collateralized basis over a similar term at an amount equal to the lease payments in a similar economic environment. In determining its incremental borrowing rate, the Company gives consideration to its credit risk, term of the lease, total lease payments and an analysis of peer companies with profiles similar to its own.

The Company has elected the short-term lease practical expedient to exclude leases with a term less than 12 months from its ROU assets and lease liabilities. The Company records rent expense for short-term leases in its statements of operations on a straight-line basis over the lease term and records variable lease payments as incurred. The Company has also elected to not separate lease and non-lease components and, as a result, accounts for any lease and non-lease components as a single lease component.

Impairment of Long-Lived Assets

Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future net cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There was no impairment of long-lived assets during the years ended December 31, 2022 and 2021.

Research and Development Expenses

Research and development costs are expensed as incurred. Research and development expenses consist primarily of personnel costs for the Company’s research and development employees. Also included are non-personnel costs such as fees paid to consultants and third parties for preclinical and clinical studies, research and development services, laboratory supplies and equipment maintenance costs, license costs, contract manufacturing costs and allocations of facility related costs. The Company estimates preclinical and clinical studies and research expenses based on the services performed, pursuant to contracts with research institutions that conduct and manage preclinical and clinical studies and research services on its behalf. We estimate the amount of work completed through review of detailed budgets and timelines included in our contracts and agreements, and update these estimates with information obtained from third-party service providers and internal personnel on a quarterly basis. 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 made to third parties

under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and are expensed as services are rendered.

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.

Stock-Based Compensation

The Company’s stock-based equity awards include restricted stock awards, stock options, restricted stock units ("RSUs"), performance-based restricted stock units ("PSUs"), and shares that will be issued under the Company’s 2020 Employee Stock Purchase Plan (“ESPP”). Stock-based compensation for awards that are granted to employees is accounted at fair value on the award grant date and the expense is recognized over the period the employee is required to provide service in exchange for the award, which is generally on a straight-line basis over the vesting period of the award. The expense is recorded in either research and development or general and administrative expenses in the statements of operations and comprehensive loss based on the function to which the related services are provided. Forfeitures are accounted for as they occur.

The Company utilizes the Monte Carlo simulation model with significant inputs including volatility and closing price of stock on grant for estimating the fair value of equity awards with market-based vesting conditions and uses the closing price of common stock on the date of grant for PSUs and RSUs with a performance or service-based vesting condition.

The Black-Scholes option-pricing model, used to estimate fair value of stock options with service-based vesting conditions, requires the use of the following assumptions:

•Expected term—The expected term represents the period that the stock-based awards are expected to be outstanding. The expected term for the Company’s stock options was calculated utilizing the simplified method, which represents the average of the weighted-average vesting term and the contract period of the awards. The expected term for the ESPP is the offering period.

•Expected volatility—Prior to the Company being public, the Company did not have any trading history for its common stock, the expected volatility was estimated based on the average historical volatilities of common stock of comparable publicly traded entities over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on their size, stage in the life cycle or area of specialty. As the Company went public in June 2020, the Company will continue to apply this process for stock options and ESPP awards until enough historical information regarding the volatility of its stock price becomes available.

•Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities approximately equal to the expected term of the awards.

•Expected dividend—The Company has never paid dividends on the common stock and has no plans to pay dividends on the common stock. Therefore, the Company used an expected dividend yield of zero.

Income Taxes

The Company provides for income taxes under the asset and liability method. Current income tax expense or benefit represents the amount of income taxes expected to be payable or refundable for the current year. Deferred income tax assets and liabilities are determined based on differences between the financial statement reporting and tax basis of assets and liabilities and net operating loss and credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when such items are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all the tax benefits will not be realized.

The Company accounts for uncertain tax positions in accordance with ASC No. 740, Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and

measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.

The Company includes any penalties and interest expense related to income taxes as a component of income tax expense, as necessary.

Comprehensive Loss

Comprehensive LossComprehensive loss includes net loss as well as other changes in stockholders' equity that result from transactions and economic events other than those with stockholders. The Company's comprehensive loss represents unrealized losses on short-term investments.

Interest and other income

Short-Term Investments

Interest and other income

Interest and other income includes interest income from our short-term investment portfolio.

Net Loss Per Share

Basic net loss per share is computed by dividing net loss attributed to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed using the weighted-average number of shares of common stock outstanding during the period and, if dilutive, the weighted-average number of potential shares of common stock.

Common stock equivalent shares are excluded from the computation of diluted net loss or income per share if their effect is antidilutive. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is generally the same as basic net loss per share attributable to common stockholders since dilutive common shares are not assumed to have been issued if their effect is antidilutive. The Company reported a net loss attributable to common stockholders during the years ended December 31, 2022 and 2021.

Novartis Collaboration and License Agreement (the "Novartis Agreement")	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Novartis Collaboration and License Agreement (the "Novartis Agreement")	Novartis Collaboration and License Agreement (the "Novartis Agreement") In 2019, we entered into the Novartis Agreement, for the development and commercialization of our preclinical product candidate, PLN-1474 and up to three additional integrin research targets. PLN-1474 is an internally discovered oral, small molecule selective inhibitor of integrin αvβ1, currently being developed for the treatment of liver fibrosis associated with nonalcoholic steatohepatitis (“NASH”). Pursuant to the agreement, we received an upfront, non-refundable license fee of $50.0 million and were eligible to receive additional payments of $416.0 million contingent upon achievement of specified research, development, regulatory and commercial events and royalties on world-wide net sales thereafter. Additionally, Novartis is funding up to $20.0 million associated with research and development services for PLN-1474 and up to $18.4 million for research and development services on the integrin research targets. We assessed the Novartis Agreement in accordance with ASC 606 and determined that Novartis is a customer and identified the following performance obligations: (1) to provide worldwide license rights to PLN-1474, (2) to provide research and development services for PLN-1474, (3) to provide non-exclusive license rights to integrin research targets, and (4) to provide research and development services on integrin research targets. We determined that the license to PLN-1474 was functional intellectual property and distinct as Novartis is capable to benefit from the license on its own or together with other resources that are readily available, and the research and development services we promise to deliver are not transformative in nature. Additionally, we concluded that the non-exclusive license rights to integrin research targets were not distinct in the context of the arrangement as the promised research and development services on integrin research targets were expected to significantly modify the license and Novartis could not benefit from the non-exclusive license without such services. Therefore, the non-exclusive license rights and research and development services on integrin research targets were considered a single performance obligation. We determined the transaction price of the PLN-1474 research and development services and integrin target research and development services was $20.0 million and $18.4 million, respectively, as of December 31, 2022, and the performance obligations associated with the aggregate unrecognized transaction price of $1.4 million would be satisfied in 2023. As of December 31, 2022, variable consideration associated with specified research and development milestones totaling $387.0 million have been constrained from the transaction prices. In February 2023, Novartis issued a termination notice for the collaboration and license agreement, and is returning global rights for PLN-1474 as well as the early research targets and associated compounds. Please refer to Note 19 to our financial statements for additional information. We are utilizing a cost-based input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. We believe this is the best measure of progress because other measures do not reflect how we transfer the performance obligation to our counterparty. In applying the cost-based input method of revenue recognition, we use actual costs incurred relative to budgeted costs to fulfill the performance obligation. These costs consist primarily of third-party contract costs and internal full-time equivalent effort. A cost-based input method of revenue recognition requires management to make estimates of costs to complete the performance obligations. The cumulative effect of revisions to estimated costs to complete the performance obligations will be recorded in the period in which changes are identified and amounts can be reasonably estimated. A significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods. In the second quarter of 2022, Novartis exercised their right to opt-in to a research program and secured an exclusive license to compounds associated with an integrin research target, which entitled us to a $4.0 million payment, which was recognized in revenue and collected during 2022. To date, we have received $29.0 million in contingent payments and $387.0 million remain eligible for achievement. During the year ended December 31, 2022, we recognized revenue of $9.7 million which consisted of revenue generated from research and development services and recognition of one contingent payment of $4.0 million associated with the integrin research target program. During the year ended December 31, 2021, we recognized revenue of $7.6 million which consisted of revenue generated from research and development services. As of December 31, 2022 and 2021, there was a receivable of $2.0 million and $2.0 million, respectively, related to the Novartis Agreement. There were no contract assets or contract liabilities as of December 31, 2022 and 2021.

Property and Equipment, net

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Property and Equipment, net

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


	December 31,
	2022		2021
Laboratory equipment	$	9,581	$	7,947
Leasehold improvements	1,650		1,618
Construction-in-progress	66		38
Computer equipment and software	30		22
Total property and equipment	11,327		9,625
Less: Accumulated depreciation	(6,841)		(5,019)
Total property and equipment, net	$	4,486	$	4,606

Depreciation expense during the years ended December 31, 2022, and 2021 was $1.8 million and $1.5 million, respectively.

Income Taxes -Narrative (Details)	12 Months Ended
Income Taxes -Narrative (Details)	Dec. 31, 2022 USD ($) taxExamination	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Income Tax Disclosure [Abstract]
Pre-tax U.S. book loss	$ (123,300,000)	$ 97,300,000
Income tax provision	$ 0	0
Valuation allowance as a percentage on total deferred tax assets	100.00%
Number of income tax examinations pending \| taxExamination	0
Unrecognized tax benefits, income tax penalties and interest expense	$ 0	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Accrued and Other Liabilities

12 Months Ended

Dec. 31, 2022

Accrued Liabilities and Other Liabilities [Abstract]

Accrued and Other Liabilities

Accrued liabilities consisted of the following (in thousands):


	December 31,
	2022		2021
Accrued compensation and benefits	7,200		5,216
Other accrued liabilities	1,458		907
Total accrued and other liabilities	$	8,658	$	6,123

Accrued compensation and benefits consist primarily of accrued bonuses and accrued vacation.

Stock-Based Compensation - Summary of Black-Scholes Option Pricing Model to Estimate Stock-based Compensation Expense for Stock Option Awards (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	0.00%
Incentive Stock Options and Nonqualified Stock Options \| 2015 Equity and 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	73.78%	74.83%
Expected volatility, maximum	80.64%	76.31%
Risk-free interest rate, minimum	1.64%	0.61%
Risk-free interest rate, maximum	4.16%	1.39%
Expected dividends	0.00%	0.00%
Incentive Stock Options and Nonqualified Stock Options \| Minimum \| 2015 Equity and 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 29 days	5 years 5 months 8 days
Underlying common stock fair value (USD per share)	$ 4.92	$ 15.20
Incentive Stock Options and Nonqualified Stock Options \| Maximum \| 2015 Equity and 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 29 days	6 years 29 days
Underlying common stock fair value (USD per share)	$ 24.23	$ 38.23

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary of Useful Lives of Property and Equipment

The useful lives of property and equipment are as follows:


Laboratory equipment			5 years
Computer equipment and software			3 years
Leasehold improvements			Shorter of remaining lease term or estimated useful life

Debt - Narrative (Details)	1 Months Ended	12 Months Ended
Debt - Narrative (Details)	Oct. 31, 2022 USD ($) tranche	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Interest expense			$ 0
Outstanding debt		$ 10,000,000	$ 0
Loan Agreement \| Term Loan Facility
Debt Instrument [Line Items]
Term loan facility	$ 100,000,000
Proceeds term loan, net of issuance costs	10,000,000
Amount available after tranche one	$ 75,000,000
Number of tranches \| tranche	3
Effective interest rate for the term loan		12.69%
Interest expense		$ 800,000
Loan Agreement \| Term Loan Facility \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Loan agreement interest rate	8.50%
Loan Agreement \| Term Loan Facility \| Debt Draw, Tranche One
Debt Instrument [Line Items]
Term loan facility	$ 25,000,000
Tranche one amount undrawn	15,000,000
Loan Agreement \| Term Loan Facility \| Debt Draw, Tranche Two
Debt Instrument [Line Items]
Term loan facility	50,000,000
Loan Agreement \| Term Loan Facility \| Debt Draw, Tranche Three
Debt Instrument [Line Items]
Term loan facility	$ 25,000,000

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Related Party TransactionsIn June 2022 and 2021, the Company granted 15,000 and 26,572 stock options with a grant date fair value of $0.1 million and $0.5 million to partners of Third Rock Ventures who were also serving as non-employee directors on the Company's Board of Directors. Both of the non-employee directors resigned from the Company's Board of Directors in 2022. The shares of common stock subject to these options vest 25% on the first day of each calendar quarter for three quarters with the final vest date being the earlier of (i) the one-year anniversary of the grant date or (ii) the next Annual Meeting of Stockholders. The stock-based compensation expense related to these options was immaterial during the years ended December 31, 2022, and 2021.

Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2020		35,552,795
Beginning balance at Dec. 31, 2020	$ 283,061	$ 3	$ 400,918	$ (32)	$ (117,828)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock awards (in shares)		103,164
Vesting of restricted stock awards	9		9
Option exercises (in shares)		427,342
Option exercises	2,984		2,984
Stock-based compensation expense	10,437		10,437
Net unrealized loss on short-term investments	(169)			(169)
Net loss	$ (97,263)				(97,263)
Ending balance (in shares) at Dec. 31, 2021	36,083,301	36,083,301
Ending balance at Dec. 31, 2021	$ 199,059	$ 3	414,348	(201)	(215,091)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock awards (in shares)		21,841
Vesting of restricted stock awards	2		2
Option exercises (in shares)		403,680
Option exercises	1,360		1,360
Stock-based compensation expense	22,598		22,598
Net unrealized loss on short-term investments	(1,757)			(1,757)
Issuance of common stock upon initial public offering/private placement (in shares)		12,432,432
Issuance of common stock upon initial public offering/private placement	215,401	$ 2	215,399
Net loss	$ (123,321)				(123,321)
Ending balance (in shares) at Dec. 31, 2022	48,941,254	48,941,254
Ending balance at Dec. 31, 2022	$ 313,342	$ 5	$ 653,707	$ (1,958)	$ (338,412)

Net Loss Per Share Attributable to Common Stockholders - Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	6,432,024	3,642,021
Performance-based restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Target level of achievement percentage	100.00%
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	5,569,567	3,620,180
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	507,925	0
Performance-based restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	354,532	0
Unvested restricted shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	0	21,841

Defined Contribution Plan (Details) - USD ($) $ in Millions	12 Months Ended
Defined Contribution Plan (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Payment made under defined contribution plan	$ 0.8	$ 0.6
Defined Contribution Plan, Plan Name [Extensible List]	Retirement Plan Name, Other [Member]	Retirement Plan Name, Other [Member]

Net Loss Per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Net Loss Per Share Attributable to Common Stockholders

The following common share equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented, because including them would have been antidilutive:


	Year Ended December 31,
	2022	2021
Options to purchase common stock	5,569,567	3,620,180
Restricted stock units	507,925	—
Performance-based restricted stock units*	354,532	—
Unvested restricted shares	—	21,841
Total	6,432,024	3,642,021
*PSUs outstanding based on target level of achievement of 100%.

A reconciliation of the numerator and denominator used in the calculation of the basic and diluted net loss per share attributable to common stockholders is as follows (in thousands, except share and per share amounts):


	Year Ended December 31,
	2022		2021
Net loss per share:
Numerator
Net loss	$	(123,321)	$	(97,263)
Net loss attributable to common stockholders	$	(123,321)	$	(97,263)
Denominator
Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders:
Basic	42,015,908		35,846,421
Diluted	42,015,908		35,846,421
Net loss per share attributable to common stockholders:
Basic	$	(2.94)	$	(2.71)
Diluted	$	(2.94)	$	(2.71)

Accrued and Other Liabilities - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued Liabilities and Other Liabilities [Abstract]
Accrued compensation and benefits	$ 7,200	$ 5,216
Other accrued liabilities	1,458	907
Total accrued and other liabilities	$ 8,658	$ 6,123

Income Taxes - Summary of Changes in Valuation Allowance for Deferred Tax Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Valuation Allowance [Abstract]
Valuation allowance at the beginning of the year	$ 67,684	$ 35,441
Increases recorded to income tax provision	38,000	32,243
Valuation allowance at the end of the year	$ 105,684	$ 67,684

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Restricted Stock Activity

The following table summarizes restricted stock activity during the year ended December 31, 2022:


	Number of Shares	Weighted- Average Grant Date Fair Value
Outstanding and unvested, as of December 31, 2021	21,841	$	2.16
Vested	(21,841)	$	2.16
Outstanding and unvested, as of December 31, 2022	—	$	—

The following table sets forth the outstanding RSUs and related activity for the year ended December 31, 2022:


	Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2021	—	—
Granted	525,825	17.43
Forfeited	(17,900)	17.30
Unvested balance as of December 31, 2022	507,925	17.43

The following table sets forth the outstanding PSUs associated with the TSR goal and related activity for the year ended December 31, 2022:


	Performance Stock Units	Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2021	—	—
Granted*	354,532	29.15
Vested	—	—
Unvested balance as of December 31, 2022*	354,532	29.15
*PSUs granted and outstanding based on target level of achievement of 100%.

The following table sets forth the outstanding PSUs associated with clinical development milestones and related activity for the year ended December 31, 2022:


	Performance Stock Units	Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2021	—	—
Granted*	354,532	17.57
Vested	(177,266)	17.57
Unvested balance as of December 31, 2022*	177,266	17.57
*PSUs granted and outstanding based on target level of achievement of 100%.

Summary of Black-Scholes Option Pricing Model to Estimate Stock-based Compensation Expense for Stock Option Awards

The Company used Black-Scholes option pricing model to estimate stock-based compensation expense for stock option awards with the following assumptions:


	Year Ended December 31,
	2022			2021
Expected volatility	73.78%	-	80.64%	74.83%	-	76.31%
Risk-free interest rate	1.64 %	-	4.16 %	0.61 %	-	1.39 %
Expected dividend	—			—
Expected term (in years)	5.33	-	6.08	5.44	-	6.08
Underlying common stock fair value	4.92	-	24.23	15.20	-	38.23

Summary of Option Activity Under the 2015 Plan and 2020 Plan

A summary of option activity under the 2015 Plan and the 2020 Plan is as follows:


	Number of Options	Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2021	3,620,180	$	14.56	8.25	$	16,735
Granted	2,517,884	$	11.65
Exercised	(140,443)	$	4.80
Forfeited	(428,054)	$	16.50
Outstanding as of December 31, 2022	5,569,567	$	13.34	7.96	$	43,696
Exercisable as of December 31, 2022	2,517,687	$	12.06	7.01	$	23,522

Schedule of Share-Based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions

The fair value of the TSR PSUs were derived from a Monte Carlo simulation model that used the following key assumptions:


Valuation date share price	$	17.57
Award term (years)	1.92
Volatility	70.62		%
Correlation coefficient	0.3508
Average peer group volatility	79.69		%
Average peer group correlation coefficient	0.4397
Risk free interest rate	2.84		%

Summary of Black-Scholes Option Pricing Model to Estimate Stock-based Compensation Expense for 2020 Employee Stock Purchase Plan

The Company used the Black-Scholes option pricing model to estimate stock-based compensation expense for the 2020 ESPP with the following assumptions:


	Year Ended December 31,
	2022	2021
Risk-free interest rate	0.60% - 3.34%	0.06% - 0.07%
Expected term of options (in years)	0.50	0.50
Expected stock price volatility	63.17% - 82.02%	67.16% - 89.51%
Expected dividends	—%	—%

Summary of Classification of Stock-based Compensation Expense

The following table presents the classification of stock-based compensation expense during the years ended December 31, 2022 and 2021 (in thousands):


	Year Ended December 31,
	2022		2021
Restricted stock awards	$	36	$	182
Stock options and ESPP	$	13,280	$	10,255
Restricted stock units	$	1,892	$	—
Performance-based restricted stock units	$	7,390	$	—
Total stock-based compensation expense	$	22,598	$	10,437
Research and development expenses	$	8,730	$	3,928
General and administrative expenses	13,867		6,509

Organization and Description of Business (Details) $ / shares in Units, $ in Millions	1 Months Ended
	Jul. 31, 2022 USD ($) $ / shares shares
Public Offering
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Public and private offering, shares issued (in shares)	12,432,432
Private Placement \| Underwriters
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Public and private offering, shares issued (in shares)	1,621,621
Public Offering And Private Placement
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Share price of shares issued (USD per share) \| $ / shares	$ 18.50
Proceeds from the sale of shares \| $	$ 215.4

Summary of Significant Accounting Policies - Summary of Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2022
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

The Company had a pre-tax U.S. book loss of $123.3 million, and $97.3 million, for the years ended December 31, 2022 and 2021, respectively. During the years ended December 31, 2022 and 2021, the Company did not record an income tax provision. The Company will continue to maintain a 100% valuation allowance on total deferred tax assets. The Company believes it is more likely than not that the related deferred tax assets will not be realized.

A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows:


	Year Ended December 31,
	2022		2021
Income tax computed at federal statutory rate	21.0	%	21.0	%
State taxes, net of federal tax benefit	7.3	%	7.7	%
General business credit—federal	3.6	%	5.3	%
Stock-based compensation	(1.0)	%	(0.7)	%
Other permanent differences	(0.4)	%	(0.1)	%
Change in valuation allowance	(30.5)	%	(33.2)	%
Effective income tax rate	0.0	%	—	%

Net deferred tax assets and liabilities consisted of the following (in thousands):


	December 31,
	2022		2021
Deferred tax assets:
Net operating losses	$	65,689	$	51,554
Research and development credits	19,688		13,989
Accrued expenses	387		292
Other	1,706		775
Capitalized research and development	13,900		—
Lease liability	1,638		2,000
Stock based compensation	5,073		1,816
Total deferred tax assets	108,081		70,426
Deferred tax liabilities:
Fixed asset basis	$	(258)	$	(61)
Prepaid expenses	(630)		(921)
Right of use asset	(1,509)		(1,760)
Total deferred tax liabilities	(2,397)		(2,742)
Valuation allowance	105,684		67,684
Net deferred taxes	$	—	$	—

Net operating losses and tax credit carryforwards were as follows (in thousands):


	December 31, 2022		Expiration Year
Net operating losses, federal (starting from January 1, 2018)	$	190,697	Does not expire
Net operating losses, federal (before January 1, 2018)	$	29,486	2035-2037
Net operating losses, state	$	278,930	2035-2042
Tax credits, federal	$	20,193	2036-2042
Tax credits, state	$	5,587	Does not expire

Utilization of the net operating loss carryforwards and research credit carryforwards may be subject to an annual limitation due to the ownership percentage change limitations provided by the Internal Revenue Code (“IRC”) and similar state provisions. Annual limitations may result in the expiration of the net operating losses and tax credit carryforwards before they are utilized. The Company performed a IRC Section 382 analysis through December 31, 2022 and does not expect any previous ownership changes to result in a limitation that will reduce the total amount of net operating loss and tax credit carryforwards disclosed that can be utilized. Subsequent ownership changes may affect the limitation in future years.

During the years ended December 31, 2022 and 2021, the Company recorded a full valuation allowance on federal and state deferred balances since management does not forecast the Company to be in a profitable position in the near future. Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2022 and 2021 related primarily to the increases in net operating loss carryforwards and research and development tax credit carryforwards and were as follows (in thousands):


	Year Ended December 31,
	2022		2021
Valuation allowance at the beginning of the year	$	67,684	$	35,441
Increases recorded to income tax provision	38,000		32,243
Valuation allowance at the end of the year	$	105,684	$	67,684

The Company’s U.S. federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2017 through December 31, 2022. There are currently no pending income tax examinations. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service and state tax authorities to the extent utilized in a future period.

The entire amount of the unrecognized tax benefits would not impact the Company’s effective tax rate if recognized. The Company's accounting policy is to include interest and penalties as a component of tax expense. During the years ended December 31, 2022 and 2021, the Company did not recognize accrued interest and penalties related to unrecognized tax benefits. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease during the next 12 months.

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


	Year Ended December 31,
	2022		2021
January 1	$	3,505	$	2,007
Additions based on tax positions related to current year	1,547		1,081
Additions for tax positions of prior year	144		417
December 31	$	5,196	$	3,505

Effective January 1, 2022, we are subject to mandatory capitalization of Section 174 research and development expenditures. The capitalized expenses are subject to amortization over five and fifteen years for expenses incurred within the U.S. and outside of U.S., respectively.

- 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 https://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 https://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 https://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 https://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 https://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 https://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 https://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 https://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 https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Financial Instruments

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Financial Instruments

The Company’s short-term investments consist of U.S. Treasury securities, U.S. Government agency securities and highly rated, investment-grade corporate debt securities with original maturities beyond three months at the date of purchase. The Company has classified and accounted for its short-term investments as available-for-sale securities as the Company may sell these securities at any time even prior to maturity and such investments represent cash available for current operations. As a result, short-term investments may include securities with maturities beyond twelve months that are classified within current assets in the Balance Sheets. The Company’s short-term investments classified as available-for-sale are carried at fair market value with unrealized losses or income recognized in other comprehensive loss.

Assets and liabilities recorded at fair value on a recurring basis in the Balance Sheets and assets and liabilities measured at fair value on a non-recurring basis or disclosed at fair value, are categorized based upon the level of judgment associated with inputs used to measure their fair values. The accounting guidance for fair value provides a framework for measuring fair value and requires certain disclosures about how fair value is determined. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. The accounting guidance also establishes a three-level valuation hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows:

•Level 1—Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

•Level 2—Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities 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 related assets or liabilities; and

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

The Company’s cash equivalent Money Market Funds are classified as Level 1 because they are valued using quoted market prices. The fair value of the Company’s U.S. Treasury securities, U.S. government agency securities and corporate debt securities are classified as Level 2 because they are valued using observable inputs to quoted market prices, benchmark yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency and include U.S. government agency securities, U.S. Treasury securities and corporate debt securities. These Level 2 instruments require more management judgment and subjectivity compared to Level 1 instruments which include determining which instruments are most similar to the instrument being priced, determining whether the market is active and determining which model-derived valuations are to be used when calculating fair value. The Company performs its analysis with the assistance of investment advisors.

There were no assets or liabilities recorded at fair value using Level 3 inputs as of December 31, 2022 and 2021.

The following tables show the Company’s cash and cash equivalents and short-term investments by significant investment category as of December 31, 2022 and 2021 (in thousands):


	As of December 31, 2022
	Adjusted Cost		Unrealized Gains		Unrealized Losses		Market Value
Level 1:
Money Market Funds	$	28,312	$	—	$	—	$	28,312
Level 2:
U.S. Treasury securities included in cash and cash equivalents and short-term investments	4,446		—		(5)		4,441
U.S. government agency securities included in short-term investments	28,746		—		(111)		28,635
Corporate debt securities included in cash and cash equivalents and short-term investments	266,267		45		(1,887)		264,425
Total financial assets	$	327,771	$	45	$	(2,003)	$	325,813


	As of December 31, 2021
	Adjusted Cost		Unrealized Gains		Unrealized Losses		Market Value
Level 1:
Money Market Funds	$	15,329	$	—	$	—	$	15,329
Level 2:
U.S. government agency securities included in short-term investments	5,003		—		—		5,003
Corporate debt securities included in cash and cash equivalents and short-term investments	163,626		1		(202)		163,425
Total financial assets	$	183,958	$	1	$	(202)	$	183,757

The Company may sell certain of its short-term securities prior to their stated maturities for reasons including, but not limited to, managing liquidity, credit risk, duration and asset allocation.

The following summarizes the remaining contractual maturities of the Company’s short-term investments as of December 31, 2022:


	Adjusted Cost		Market Value
Mature in 1 year or less	$	252,238	$	250,682
Mature in 1 to 2 years	47,222		46,820
Total	$	299,460	$	297,502

There were no liabilities measured at fair value on a recurring basis as of December 31, 2022 and 2021. There have been no transfers between fair value measurement levels during the years ended December 31, 2022 and 2021. In

addition, there were no assets or liabilities measured at fair value on a non-recurring basis as of December 31, 2022 and 2021.

As of December 31, 2022, the Company had not recorded any impairment related to other-than-temporary declines in the fair value of short-term investments.

The Company records interest income and accretion income earned on Money Market Funds and U.S. Treasury, U.S. government agency and corporate debt securities to interest and other income in its statement of operations and comprehensive loss.

- 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

Stock-Based Compensation

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Equity Incentive Plans

In 2015, the Company's Board of Directors adopted the 2015 Equity Incentive Plan, as amended in 2018, 2019 and 2020 (the “2015 Plan”), which provided for the grant of incentive stock options, nonqualified stock options or other awards including stock appreciation rights and restricted stock awards to the Company’s employees, officers, directors, advisors, and consultants. In May 2020, the Board of Directors adopted the 2020 Stock Option and Incentive Plan (the “2020 Plan”) and suspended the 2015 Plan. Awards outstanding under either the 2015 Plan or 2020 Plan that are cancelled, expire or otherwise terminated subsequent to May 2020 will become available for issuance as common stock under the 2020 Plan. Additionally, the 2020 Plan is subject to automatic increases on January 1 of each year beginning January 1, 2021. The number of shares added each January 1 will be equal to the lesser of: (i) 5% of the outstanding shares on the immediately preceding December 31 or (ii) such amount as determined by the administrator of the 2020 Plan, which is the compensation committee of the Board of Directors of the Company.

The 2020 Plan provides for the grant of incentive stock options, nonqualified stock options or other awards including stock appreciation rights, restricted stock awards and restricted stock units to the Company’s employees, officers, directors, advisors, and consultants. As of December 31, 2022, the 2020 Plan had 2,937,769 shares of common stock available for future issuance.

In 2022, the Board of Directors adopted the 2022 Inducement Plan ("Inducement Plan"), under which the Company may grant restricted stock units, stock options, stock appreciation rights, and restricted stock awards. As of December 31, 2022, 1,000,000 shares of common stock were available for issuance.

Options under the 2020 Plan may be granted for periods of up to 10 years and at prices no less than the market price of the Company’s common stock on the date of grant, provided, however, that the exercise price of an incentive stock option granted to a 10% shareholder shall not be less than 110% of the estimated fair value of the shares on the date of grant and the option is not exercisable after the expiration of five years from the date of grant.

Restricted Common Stock Awards

The Company granted restricted stock awards under the 2015 Plan. The purchase price of the restricted common stock awards was the estimated fair value as determined by the Company's Board of Directors at the issuance date. The shares vest from one to four years and vesting could be accelerated upon a change in control. A holder of an award may pay a total purchase price or a part of the purchase price for granted shares at any time during the vesting periods. Upon termination of employment, the Company has the right to repurchase any unvested restricted shares. The repurchase price for unvested shares of common stock will be the lower of (i) the fair market value on the date of repurchase or (ii) their original purchase price. During the vesting term, holders of restricted stock awards are deemed to be common stock shareholders and have dividends and voting rights.

The Company accounted for restricted stock awards as early exercised options and recognized a liability in other liabilities when cash was received for the purchase of shares of restricted stock. As shares of restricted stock vested, the Company reclassified the liability to common stock and additional paid in capital. As of December 31, 2022 and 2021, the Company recorded a liability included in accrued expenses and other liabilities of nil and $2,000, respectively.

There were no grants of restricted stock awards during the years ended December 31, 2022 and 2021.

The following table summarizes restricted stock activity during the year ended December 31, 2022:


	Number of Shares	Weighted- Average Grant Date Fair Value
Outstanding and unvested, as of December 31, 2021	21,841	$	2.16
Vested	(21,841)	$	2.16
Outstanding and unvested, as of December 31, 2022	—	$	—

The aggregate fair value of restricted stock awards vested during the years ended December 31, 2022 and 2021 was $47,000 and $0.2 million, respectively. Total intrinsic value of outstanding unvested restricted stock awards as of December 31, 2022 and 2021 was nil and $0.3 million, respectively. As of December 31, 2022, there was no unrecognized compensation costs related to restricted stock awards.

Incentive Stock Options and Nonqualified Stock Options

Stock options issued under either the 2015 Plan or the 2020 Plan generally vest over four years and expire ten years from the date of grant. Certain options provide for accelerated vesting if there is a change in control, as defined in the respective plans.

The Company used Black-Scholes option pricing model to estimate stock-based compensation expense for stock option awards with the following assumptions:


	Year Ended December 31,
	2022			2021
Expected volatility	73.78%	-	80.64%	74.83%	-	76.31%
Risk-free interest rate	1.64 %	-	4.16 %	0.61 %	-	1.39 %
Expected dividend	—			—
Expected term (in years)	5.33	-	6.08	5.44	-	6.08
Underlying common stock fair value	4.92	-	24.23	15.20	-	38.23

A summary of option activity under the 2015 Plan and the 2020 Plan is as follows:


	Number of Options	Weighted- Average Exercise Price per Share		Weighted- Average Remaining Contractual Term (in Years)	Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2021	3,620,180	$	14.56	8.25	$	16,735
Granted	2,517,884	$	11.65
Exercised	(140,443)	$	4.80
Forfeited	(428,054)	$	16.50
Outstanding as of December 31, 2022	5,569,567	$	13.34	7.96	$	43,696
Exercisable as of December 31, 2022	2,517,687	$	12.06	7.01	$	23,522

As of December 31, 2022, there was $27.7 million of unrecognized compensation costs that is expected to be recognized over the weighted-average periods of 2.6 years related to stock options. The total intrinsic value of time-based stock options exercised was $2.0 million and $6.9 million for December 31, 2022 and 2021, respectively. Intrinsic value represents the difference between the current fair value of the underlying stock and the exercise price of the stock option. The weighted-average grant date fair value of options granted during years ended December 31, 2022 and 2021 was $7.82 per share and $16.94 per share, respectively.

Restricted Stock Units

The service-based condition for restricted stock units ("RSUs") is generally satisfied over two years. The following table sets forth the outstanding RSUs and related activity for the year ended December 31, 2022:


	Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2021	—	—
Granted	525,825	17.43
Forfeited	(17,900)	17.30
Unvested balance as of December 31, 2022	507,925	17.43

As of December 31, 2022, the Company had $6.9 million of unrecognized stock-based compensation expense related to outstanding RSUs expected to be recognized over a weighted-average period of 1.6 years.

Performance-Based Restricted Stock Units

Performance-based restricted stock units ("PSUs") vest upon the achievement of market and performance conditions. Market conditions include the Company's total shareholder return ("TSR") relative to the NASDAQ Biotechnology Index over the term of the award ending on June 30, 2024, and performance conditions consist of multiple clinical development milestones associated with bexotegrast. The performance vesting conditions generally must be satisfied within a two-year period and are forfeited if the vesting conditions are not met. Additionally, the number of shares of common stock issued upon vesting will range from 0% to 200% of the PSUs based on achievement of certain targets.

The fair value of PSUs with clinical development vesting conditions were determined to be equal to the fair market value of the Company's share price on the date of grant. The fair value of the TSR PSUs were derived from a Monte Carlo simulation model that used the following key assumptions:


Valuation date share price	$	17.57
Award term (years)	1.92
Volatility	70.62		%
Correlation coefficient	0.3508
Average peer group volatility	79.69		%
Average peer group correlation coefficient	0.4397
Risk free interest rate	2.84		%

The following table sets forth the outstanding PSUs associated with the TSR goal and related activity for the year ended December 31, 2022:


	Performance Stock Units	Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2021	—	—
Granted*	354,532	29.15
Vested	—	—
Unvested balance as of December 31, 2022*	354,532	29.15
*PSUs granted and outstanding based on target level of achievement of 100%.

The following table sets forth the outstanding PSUs associated with clinical development milestones and related activity for the year ended December 31, 2022:


	Performance Stock Units	Weighted Average Grant Date Fair Value
Unvested balance as of December 31, 2021	—	—
Granted*	354,532	17.57
Vested	(177,266)	17.57
Unvested balance as of December 31, 2022*	177,266	17.57
*PSUs granted and outstanding based on target level of achievement of 100%.

In December 2022, the first milestone applicable to PSUs with clinical development vesting conditions was achieved, resulting in a $3.1 million cumulative catch-up of stock-based compensation expense for such PSUs. As of December 31, 2022 the Company considered the remaining clinical development performance conditions probable of achievement.

As of December 31, 2022, the Company had $15.4 million of unrecognized stock-based compensation expense related to outstanding PSUs expected to be recognized over a remaining weighted-average period of 1.6 years.

2020 Employee Stock Purchase Plan

In June 2020, the Company adopted the Company's 2020 Employee Stock Purchase Plan (the "2020 ESPP"). The Company reserved 700,000 shares of common stock for future issuance under the plan. The 2020 ESPP provides that the number of shares reserved and available for issuance will automatically increase on January 1 of each calendar year, beginning January 1, 2021, by the least of (i) 1.0% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, (ii) 700,000 shares or (iii) such lesser amount as determined by the administrator of the 2020 ESPP, which is the compensation committee of the Board of Directors of the Company.

Under the 2020 ESPP, eligible employees may purchase shares of our common stock through payroll deductions that cannot exceed 15% of each employee’s salary. The 2020 ESPP provides for a six-month offering period. At the end of the purchase period, eligible employees are permitted to purchase shares of common stock at the lower of 85% of the fair market value at the beginning of the offering period or 85% of the fair market value at the end of the purchase period, subject to tax limitations on the total value of the purchase. The 2020 ESPP is considered a compensatory plan, and the Company recorded $0.4 million and $0.5 million in stock-based compensation expense for years ended December 31, 2022, and 2021, respectively. During the year ended December 31, 2022, 85,969 shares of common stock were issued under the 2020 ESPP. The Company used the Black-Scholes option pricing model to estimate stock-based compensation expense for the 2020 ESPP with the following assumptions:


	Year Ended December 31,
	2022	2021
Risk-free interest rate	0.60% - 3.34%	0.06% - 0.07%
Expected term of options (in years)	0.50	0.50
Expected stock price volatility	63.17% - 82.02%	67.16% - 89.51%
Expected dividends	—%	—%

Stock-Based Compensation Expense

The following table presents the classification of stock-based compensation expense during the years ended December 31, 2022 and 2021 (in thousands):


	Year Ended December 31,
	2022		2021
Restricted stock awards	$	36	$	182
Stock options and ESPP	$	13,280	$	10,255
Restricted stock units	$	1,892	$	—
Performance-based restricted stock units	$	7,390	$	—
Total stock-based compensation expense	$	22,598	$	10,437
Research and development expenses	$	8,730	$	3,928
General and administrative expenses	13,867		6,509

Stock-Based Compensation - Schedule of TSR PSU Valuation Assumptions (Details) - Performance-based restricted stock units	12 Months Ended
	Dec. 31, 2022 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Valuation date share price (in dollars per share)	$ 17.57
Expected term (in years)	1 year 11 months 1 day
Volatility	70.62%
Correlation coefficient	0.3508
Average peer group volatility	79.69%
Average peer group correlation coefficient	0.4397
Risk-free interest rate	2.84%

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Summary of Reconciliation of U.S. Federal Statutory Income Tax Rate to Company’s Effective Income Tax Rate

A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows:


	Year Ended December 31,
	2022		2021
Income tax computed at federal statutory rate	21.0	%	21.0	%
State taxes, net of federal tax benefit	7.3	%	7.7	%
General business credit—federal	3.6	%	5.3	%
Stock-based compensation	(1.0)	%	(0.7)	%
Other permanent differences	(0.4)	%	(0.1)	%
Change in valuation allowance	(30.5)	%	(33.2)	%
Effective income tax rate	0.0	%	—	%

Summary of Deferred Tax Assets and Liabilities

Net deferred tax assets and liabilities consisted of the following (in thousands):


	December 31,
	2022		2021
Deferred tax assets:
Net operating losses	$	65,689	$	51,554
Research and development credits	19,688		13,989
Accrued expenses	387		292
Other	1,706		775
Capitalized research and development	13,900		—
Lease liability	1,638		2,000
Stock based compensation	5,073		1,816
Total deferred tax assets	108,081		70,426
Deferred tax liabilities:
Fixed asset basis	$	(258)	$	(61)
Prepaid expenses	(630)		(921)
Right of use asset	(1,509)		(1,760)
Total deferred tax liabilities	(2,397)		(2,742)
Valuation allowance	105,684		67,684
Net deferred taxes	$	—	$	—

Summary of Net Operating Losses and Tax Credit Carryforwards

Net operating losses and tax credit carryforwards were as follows (in thousands):


	December 31, 2022		Expiration Year
Net operating losses, federal (starting from January 1, 2018)	$	190,697	Does not expire
Net operating losses, federal (before January 1, 2018)	$	29,486	2035-2037
Net operating losses, state	$	278,930	2035-2042
Tax credits, federal	$	20,193	2036-2042
Tax credits, state	$	5,587	Does not expire

Summary of Changes in Valuation Allowance for Deferred Tax Assets

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2022 and 2021 related primarily to the increases in net operating loss carryforwards and research and development tax credit carryforwards and were as follows (in thousands):


	Year Ended December 31,
	2022		2021
Valuation allowance at the beginning of the year	$	67,684	$	35,441
Increases recorded to income tax provision	38,000		32,243
Valuation allowance at the end of the year	$	105,684	$	67,684

Summary of Reconciliation of Unrecognized Tax Benefits

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


	Year Ended December 31,
	2022		2021
January 1	$	3,505	$	2,007
Additions based on tax positions related to current year	1,547		1,081
Additions for tax positions of prior year	144		417
December 31	$	5,196	$	3,505

Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2022

Earnings Per Share [Abstract]

Summary of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share


	Year Ended December 31,
	2022	2021
Options to purchase common stock	5,569,567	3,620,180
Restricted stock units	507,925	—
Performance-based restricted stock units*	354,532	—
Unvested restricted shares	—	21,841
Total	6,432,024	3,642,021
*PSUs outstanding based on target level of achievement of 100%.

Reconciliation of Numerator and Denominator Used in Calculation of Basic and Diluted Net Loss Per Share


	Year Ended December 31,
	2022		2021
Net loss per share:
Numerator
Net loss	$	(123,321)	$	(97,263)
Net loss attributable to common stockholders	$	(123,321)	$	(97,263)
Denominator
Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders:
Basic	42,015,908		35,846,421
Diluted	42,015,908		35,846,421
Net loss per share attributable to common stockholders:
Basic	$	(2.94)	$	(2.71)
Diluted	$	(2.94)	$	(2.71)

Leases - Schedule of Operating Lease Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating Leases, After Adoption of 842:
2023	$ 2,836
2024	2,422
2025	1,202
2026	0
2027	0
Total lease payments	6,460
Less: Present value discount	574
Total current operating lease liabilities	2,457	$ 1,869
Lease liabilities, non-current	$ 3,429	$ 5,325

Leases - Weighted-average Remaining Lease Terms and Discount Rates (Details)	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Weighted-average remaining lease term (in years)	2 years 3 months 18 days	3 years 4 months 24 days
Weighted-average discount rate	8.20%	7.90%

Accrued and Other Liabilities (Tables)

12 Months Ended

Dec. 31, 2022

Accrued Liabilities and Other Liabilities [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):


	December 31,
	2022		2021
Accrued compensation and benefits	7,200		5,216
Other accrued liabilities	1,458		907
Total accrued and other liabilities	$	8,658	$	6,123

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Jan. 31, 2023	Jul. 31, 2022
Public Offering
Subsidiary, Sale of Stock [Line Items]
Public and private offering, shares issued (in shares)		12,432,432
Public Offering \| Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Public and private offering, shares issued (in shares)	9,583,334
Private Placement \| Underwriters
Subsidiary, Sale of Stock [Line Items]
Public and private offering, shares issued (in shares)		1,621,621
Private Placement \| Underwriters \| Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Public and private offering, shares issued (in shares)	1,250,000
Public Offering And Private Placement
Subsidiary, Sale of Stock [Line Items]
Share price of shares issued (USD per share)		$ 18.50
Proceeds from the sale of shares		$ 215.4
Public Offering And Private Placement \| Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Share price of shares issued (USD per share)	$ 30.00
Public Offering And Private Placement \| Underwriters \| Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Proceeds from the sale of shares	$ 269.9

Stock-Based Compensation - Restricted Common Stock Awards - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 0
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted during period (in shares)	0	0
Aggregate fair value of restricted stock awards vested	$ 47,000	$ 200,000
Total intrinsic value of outstanding unvested restricted stock awards	0	300,000
Restricted stock awards \| Accrued Expenses and Other Liabilities
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued expenses and other liabilities	$ 0	$ 2,000
Minimum \| Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Maximum \| Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Prepaid Expenses and Other Current Assets

12 Months Ended

Dec. 31, 2022

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31,
	2022		2021
Prepaid research and development	$	3,421	$	2,819
Prepaid insurance	1,427		2,585
Prepaid licenses	959		819
Interest receivable	1,078		385
Other	173		156
Total prepaid expenses and other current assets	$	7,058	$	6,764

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (123,321)	$ (97,263)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,823	1,535
Stock-based compensation expense	22,598	10,437
Noncash lease expense	1,858	1,669
(Accretion) amortization on short-term investments	(1,806)	1,262
Changes in operating assets and liabilities:
Accounts receivable	15	7,281
Prepaid expenses and other current assets	(294)	(2,266)
Other non-current assets	201	70
Accounts payable	(1,351)	891
Accrued liabilities	7,904	2,695
Operating lease liabilities	(2,258)	(1,754)
Net cash used in operating activities	(94,631)	(75,443)
Cash flows from investing activities:
Purchase of short-term investments	(325,716)	(219,887)
Maturity of short-term investments	177,272	295,539
Purchase of property and equipment	(1,760)	(1,953)
Net cash (used in) provided by investing activities	(150,204)	73,699
Cash flows from financing activities:
Proceeds from sale of common stock in a public offering	216,201	0
Proceeds term loan, net of issuance costs	9,850	0
Proceeds from issuances of common stock under benefit plans	1,360	2,984
Payment of offering costs	(557)	(457)
Net cash provided by financing activities	226,854	2,527
Net (decrease) increase in cash and cash equivalents	(17,981)	783
Cash and cash equivalents at beginning of period	51,665	50,882
Cash and cash equivalents at end of period	33,684	51,665
Supplemental disclosures of cash flow information:
Cash paid for interest	615	0
Supplemental disclosures of noncash investing and financing activities:
Purchase of property and equipment in accounts payable and accrued liabilities	0	57
Reclassification of restricted stock awards from liabilities to common stock upon vesting	2	9
Net unrealized loss on short-term investments	(1,757)	(169)
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 950	$ 0

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Accounting Policies [Line Items]
Percentage of revenue contributed by related party	100.00%	100.00%
Number of operating segments	1
Number of reportable segments	1
Debt instrument remaining maturity period at date of purchase	3 months
Impairment of long-lived assets \| $	$ 0	$ 0	$ 0
Expected dividends	0.00%
Novartis Agreement
Accounting Policies [Line Items]
Description of customer payment terms	The Company performs credit evaluations of its customer, and the risk with respect to accounts receivable is further mitigated by the short duration of customer payment terms, generally within 60 days, and the pedigree of the customer base.

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 33,685	$ 51,665
Short-term investments	297,502	148,931
Accounts receivable	1,983	1,998
Tax credit receivable	83	83
Prepaid expenses and other current assets	7,058	6,764
Total current assets	340,311	209,441
Property and equipment, net	4,486	4,606
Operating lease right-of-use assets	5,422	6,330
Other non-current assets	394	838
Total assets	350,613	221,215
Current liabilities
Accounts payable	1,580	2,971
Accrued research and development	11,218	5,868
Accrued and other liabilities	8,658	6,123
Lease liabilities, current	2,457	1,869
Total current liabilities	23,913	16,831
Lease liabilities, non-current	3,429	5,325
Long-term debt	9,929	0
Total liabilities	37,271	22,156
Commitments and contingencies
Stockholders’ equity
Common stock, $0.0001 par value; 300,000,000 shares authorized at December 31, 2022 and 2021; and 48,941,254 and 36,083,301 shares issued and outstanding at December 31, 2022 and 2021, respectively;	5	3
Additional paid-in capital	653,707	414,348
Accumulated deficit	(338,412)	(215,091)
Accumulated other comprehensive loss	(1,958)	(201)
Total stockholders’ equity	313,342	199,059
Total liabilities and stockholders’ equity	$ 350,613	$ 221,215

Defined Contribution Plan	12 Months Ended
Defined Contribution Plan	Dec. 31, 2022
Retirement Benefits [Abstract]
Defined Contribution Plan	Defined Contribution PlanThe Company sponsors a defined contribution plan under Section 401(k) of the Internal Revenue Code covering substantially all full-time U.S. employees. Employee contributions are voluntary and are determined on an individual basis subject to the maximum allowable under federal tax regulations. The Company made contributions to the plan of $0.8 million and $0.6 million during the years ended December 31, 2022 and 2021, respectively.

Financial Instruments - Summery of Remaining Contractual Maturities of Company's Short-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	$ 327,771	$ 183,958
Market Value	325,813	$ 183,757
Short Term Investments
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	299,460
Market Value	297,502
Short Term Investments \| Mature in 1 year or less
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	252,238
Market Value	250,682
Short Term Investments \| Mature in 1 to 2 years
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	47,222
Market Value	$ 46,820

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Basis of Presentation

Use of Estimates

Revenue Recognition

Licenses of Intellectual Property

Milestone Payments

Research and development services

Royalties:

Fair Value Measurements

Concentration of Credit Risk and Other Risks and Uncertainties

of the customer base. During the years ended December 31, 2022 and 2021, Novartis accounted for 100% of the Company’s revenue and accounts receivable.

Segments

Cash and Cash Equivalents

Short-Term Investments

Property and Equipment, Net


Laboratory equipment			5 years
Computer equipment and software			3 years
Leasehold improvements			Shorter of remaining lease term or estimated useful life

Leases

Impairment of Long-Lived Assets

Research and Development Expenses

under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and are expensed as services are rendered.

Stock-Based Compensation

The Black-Scholes option-pricing model, used to estimate fair value of stock options with service-based vesting conditions, requires the use of the following assumptions:

•Expected dividend—The Company has never paid dividends on the common stock and has no plans to pay dividends on the common stock. Therefore, the Company used an expected dividend yield of zero.

Income Taxes

measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.

The Company includes any penalties and interest expense related to income taxes as a component of income tax expense, as necessary.

Comprehensive Loss

Comprehensive loss includes net loss as well as other changes in stockholders' equity that result from transactions and economic events other than those with stockholders. The Company's comprehensive loss represents unrealized losses on short-term investments.

Interest and other income

Interest and other income includes interest income from our short-term investment portfolio.

Net Loss Per Share

Common Stock - Narrative (Details)	12 Months Ended
Common Stock - Narrative (Details)	Dec. 31, 2022 vote $ / shares shares	Dec. 31, 2021 $ / shares shares
Equity [Abstract]
Common stock, shares authorized (in shares) \| shares	300,000,000	300,000,000
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Common stock, voting rights \| vote	1
Dividends declared (USD per share)	$ 0
Dividends paid (USD per share)	$ 0

Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2022	Mar. 05, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39303
Entity Registrant Name	PLIANT THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-4272481
Entity Address, Address Line One	260 Littlefield Avenue
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	481-6770
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	PLRX
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 281,511,770
Entity Common Stock, Shares Outstanding		58,939,667
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive Proxy Statement for the 2023 Annual Meeting of Stockholders to be filed with the U.S. Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K are incorporated by reference in Part III, Items 10-14 of this Annual Report on Form 10-K
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Central Index Key	0001746473

Stock-Based Compensation - Incentive Stock Options and Nonqualified Stock Options - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Incentive Stock Options and Nonqualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 27.7
Unrecognized compensation expense, weighted average period	2 years 7 months 6 days
Intrinsic value of time-based stock options exercised	$ 2.0	$ 6.9
Grant date fair value of stock option (in dollars per share)	$ 7.82	$ 16.94
2015 Equity and 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Expiration period from date of grant	10 years

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 9,685	$ 7,572
Operating expenses:
Research and development	(96,936)	(77,549)
General and administrative	(39,949)	(27,558)
Total operating expenses	(136,885)	(105,107)
Loss from operations	(127,200)	(97,535)
Interest and other income (expense), net	4,670	272
Interest expense	(791)	0
Net loss	(123,321)	(97,263)
Net loss attributable to common stockholders	(123,321)	(97,263)
Net loss attributable to common stockholders	$ (123,321)	$ (97,263)
Net loss per share, attributable to common stockholders:
Basic (USD per share)	$ (2.94)	$ (2.71)
Diluted (USD per share)	$ (2.94)	$ (2.71)
Shares used in computing net loss per share attributable to common stockholders:
Basic (in shares)	42,015,908	35,846,421
Diluted (in shares)	42,015,908	35,846,421
Comprehensive loss:
Net loss	$ (123,321)	$ (97,263)
Other comprehensive loss:
Net unrealized loss on short-term investments	(1,757)	(169)
Total other comprehensive loss	(1,757)	(169)
Comprehensive loss	$ (125,078)	$ (97,432)

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid research and development	$ 3,421	$ 2,819
Prepaid insurance	1,427	2,585
Prepaid licenses	959	819
Interest receivable	1,078	385
Other	173	156
Total prepaid expenses and other current assets	$ 7,058	$ 6,764

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsIn January 2023, the Company completed a public offering of 9,583,334 shares of common stock, including the exercise in full of the underwriters' option to purchase 1,250,000 additional shares of common stock. The shares were offered at a price of $30.00 per share, resulting in aggregate proceeds of approximately $269.9 million, net of underwriting discounts, commissions and offering expenses. On February 17, 2023, we received notice from Novartis Institutes for BioMedical Research, Inc. (“Novartis”) that Novartis has elected to exercise its right to terminate the Collaboration and License Agreement by and between the Company and Novartis, dated October 17, 2019 (the “Collaboration Agreement”), as amended by Amendment No. 1 to the Collaboration and License Agreement between the Company and Novartis, dated as of November 15, 2022 (“Amendment No. 1”). Novartis informed the Company of its decision, as part of its new strategy focusing on a limited number of therapeutic areas, to divest clinical NASH assets and, as a result, to discontinue the development of PLN-1474, a small molecule selective inhibitor of integrin αvß1, being developed for the treatment of liver fibrosis associated with NASH. The termination will take effect on April 18, 2023. Effective upon the termination of the Collaboration Agreement, all rights and licenses granted thereunder, including development candidates targeting the validated Research Target, PLN-1474 and the related IND, will revert back to the Company. The payment obligations of Novartis with respect to future milestones, royalties and research and development funding will also terminate.

Stock-Based Compensation - Summary of Restricted Stock Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares
Restricted stock awards
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding and unvested, beginning balance (in shares) \| shares	21,841
Vested (in shares) \| shares	(21,841)
Outstanding and unvested, ending balance (in shares) \| shares	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date fair value, Outstanding and unvested, beginning balance (USD per share) \| $ / shares	$ 2.16
Weighted-Average Grant Date fair value, Vested (USD per share) \| $ / shares	2.16
Weighted-Average Grant Date fair value, Outstanding and unvested, ending balance (USD per share) \| $ / shares	$ 0
Restricted stock units
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding and unvested, beginning balance (in shares) \| shares	0
Granted (in shares) \| shares	525,825
Forfeited (in shares) \| shares	(17,900)
Outstanding and unvested, ending balance (in shares) \| shares	507,925
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date fair value, Outstanding and unvested, beginning balance (USD per share) \| $ / shares	$ 0
Weighted-Average Grant Date fair value, Issued (USD per share) \| $ / shares	17.43
Weighted- Average Exercise Price per Share, Forfeited (USD per share) \| $ / shares	17.30
Weighted-Average Grant Date fair value, Outstanding and unvested, ending balance (USD per share) \| $ / shares	$ 17.43
Vesting period	2 years
Unrecognized compensation cost \| $	$ 6.9
Unrecognized compensation expense, weighted average period	1 year 7 months 6 days
Performance-based restricted stock units
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Target level of achievement percentage	100.00%
Vesting period	2 years
Unrecognized compensation cost \| $	$ 15.4
Unrecognized compensation expense, weighted average period	1 year 7 months 6 days
Performance-Based Restricted Stock Units, TSR Goal
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding and unvested, beginning balance (in shares) \| shares	0
Granted (in shares) \| shares	354,532
Forfeited (in shares) \| shares	0
Outstanding and unvested, ending balance (in shares) \| shares	354,532
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date fair value, Outstanding and unvested, beginning balance (USD per share) \| $ / shares	$ 0
Weighted-Average Grant Date fair value, Issued (USD per share) \| $ / shares	29.15
Weighted- Average Exercise Price per Share, Forfeited (USD per share) \| $ / shares	0
Weighted-Average Grant Date fair value, Outstanding and unvested, ending balance (USD per share) \| $ / shares	$ 29.15
Performance-Based Restricted Stock Units, Clinical Development Milestones
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding and unvested, beginning balance (in shares) \| shares	0
Granted (in shares) \| shares	354,532
Vested (in shares) \| shares	(177,266)
Outstanding and unvested, ending balance (in shares) \| shares	177,266
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date fair value, Outstanding and unvested, beginning balance (USD per share) \| $ / shares	$ 0
Weighted-Average Grant Date fair value, Issued (USD per share) \| $ / shares	17.57
Weighted-Average Grant Date fair value, Vested (USD per share) \| $ / shares	17.57
Weighted-Average Grant Date fair value, Outstanding and unvested, ending balance (USD per share) \| $ / shares	$ 17.57

Income Taxes - Summary of Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense [Abstract]
January 1	$ 3,505	$ 2,007
Additions based on tax positions related to current year	1,547	1,081
Additions for tax positions of prior year	144	417
December 31	$ 5,196	$ 3,505

Stock-Based Compensation - Restricted Stock Units and Performance-Based Restricted Stock Units - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense		$ 22,598	$ 10,437
Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		2 years
Unrecognized compensation cost	$ 15,400	$ 15,400
Unrecognized compensation expense, weighted average period		1 year 7 months 6 days
Share-based payment arrangement, expense		$ 7,390	0
Performance-based restricted stock units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights, percentage		0.00%
Performance-based restricted stock units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights, percentage		200.00%
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		2 years
Unrecognized compensation cost	6,900	$ 6,900
Unrecognized compensation expense, weighted average period		1 year 7 months 6 days
Share-based payment arrangement, expense		$ 1,892	$ 0
Performance-Based Restricted Stock Units, Clinical Development Milestones
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 3,100

Stock-Based Compensation - 2020 Employee Stock Purchase Plan - Summary of Black-Scholes Option Pricing Model to Estimate Stock-based Compensation Expense for 2020 Employee Stock Purchase Plan (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividends	0.00%
Shares of common stock available for future issuance under the 2020 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	0.60%	0.06%
Risk-free interest rate, maximum	3.34%	0.07%
Expected term (in years)	6 months	6 months	0 years
Expected volatility, minimum	63.17%	67.16%
Expected volatility, maximum	82.02%	89.51%
Expected dividends	0.00%	0.00%

Stock-Based Compensation - Summary of Option Activity Under the 2015 Plan and 2020 Plan (Details) - 2015 Equity and 2020 Incentive Plan - Incentive Stock Options and Nonqualified Stock Options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Number of Options, Outstanding, Beginning balance (in shares)	3,620,180
Options granted (in shares)	2,517,884
Number of Options, Exercised (in shares)	(140,443)
Number of Options, Forfeited (in shares)	(428,054)
Number of Options, Outstanding, Ending balance (in shares)	5,569,567	3,620,180
Number of Options, Exercisable (in shares)	2,517,687
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted- Average Exercise Price per Share, Outstanding, Beginning balance (USD per share)	$ 14.56
Weighted- Average Exercise Price per Share, Granted (USD per share)	11.65
Weighted- Average Exercise Price per Share, Exercised (USD per share)	4.80
Weighted- Average Exercise Price per Share, Forfeited (USD per share)	16.50
Weighted- Average Exercise Price per Share, Outstanding, Ending balance (USD per share)	13.34	$ 14.56
Weighted- Average Exercise Price per Share, Exercisable (USD per share)	$ 12.06
Weighted- Average Remaining Contractual Term (in Years), Outstanding	7 years 11 months 15 days	8 years 3 months
Weighted- Average Remaining Contractual Term (in Years), Exercisable	7 years 3 days
Aggregate Intrinsic Value, Outstanding balance	$ 43,696	$ 16,735
Aggregate Intrinsic Value, Exercisable	$ 23,522

Property and Equipment, net - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,823	$ 1,535

Leases (Tables)

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Schedule of Operating Lease Liability

The undiscounted future non-cancellable lease payments of the Company's operating lease liability as of December 31, 2022 were as follows (in thousands):


Year ending December 31:	Operating Leases
2023	$	2,836
2024	2,422
2025	1,202
2026	—
2027	—
Total lease payments	$	6,460
Less: Present value discount	574
Total current operating lease liabilities	$	2,457
Total non-current operating lease liabilities	$	3,429

Schedule of Weighted-average Remaining Lease Terms and Discount Rates

The weighted-average remaining lease terms and discount rates related to the Company's operating leases were as follows:


	As of December 31,
	2022		2021
Weighted-average remaining lease term (in years)	2.30		3.40
Weighted-average discount rate	8.20	%	7.9	%

Debt

12 Months Ended

Dec. 31, 2022

Debt Disclosure [Abstract]

Debt Disclosure

Debt

In May 2022, as amended in October 2022, we entered into a term loan facility (the “Oxford Loan Agreement”) with Oxford Finance LLC (the "Lender") for up to $100.0 million. At closing, we entered into a term loan for $10.0 million of an initial $25.0 million tranche, with the remaining $15.0 million available through mid-February 2023. The Oxford Loan Agreement provides for an additional $75.0 million over three tranches, $50.0 million of which is at our option upon the satisfaction of certain conditions related to the development of bexotegrast and one of our preclinical product candidates, and $25.0 million at the Lender's discretion. In connection with the Oxford Loan Agreement, we granted a security interest in substantially all of our current and future assets. There are no warrants or financial covenants associated with the Oxford Loan Agreement.

Borrowings under the Oxford Loan Agreement bear interest at a rate per annum equal to 1-month term Secured Overnight Financing Rate (SOFR) plus 8.5%, subject to an agreed upon floor and cap. The Oxford Loan Agreement requires the Company to make monthly interest-only payments until July 1, 2026 (extendable to July 1, 2027) with monthly interest and principal payments thereafter until the maturity date of May 1, 2027 (extendable to May 1, 2028).

The estimated fair value of the term loan as of December 31, 2022 was measured using Level 3 inputs and approximates the carrying value recorded to the balance sheet. The effective interest rate for the term loan is 12.69% and interest expense during the year ended December 31, 2022 was $0.8 million. We had no outstanding debt and did not incur interest expense in 2021.

Future maturities of debt as of December 31, 2022 are as follows (in thousands):


	As of December 31, 2022
2023	$	—
2024	—
2025	—
2026	5,455
2027	4,545
Thereafter	$	—
Total	$	10,000
Less: unamortized debt issuance costs	(133)
Accretion of final payment	62
Total	$	9,929

- 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 https://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 https://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 https://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (a)
-URI https://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 https://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 https://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 https://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 https://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 https://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 https://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 https://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 https://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 https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

Stock-Based Compensation - 2020 Employee Stock Purchase Plan Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance (in shares)		11,435,241	8,467,491
Share-based payment arrangement, expense		$ 22,598	$ 10,437
Shares of common stock available for future issuance under the 2020 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance (in shares)	700,000
Employee stock purchase plan, description	The 2020 ESPP provides that the number of shares reserved and available for issuance will automatically increase on January 1 of each calendar year, beginning January 1, 2021, by the least of (i) 1.0% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, (ii) 700,000 shares or (iii) such lesser amount as determined by the administrator of the 2020 ESPP, which is the compensation committee of the Board of Directors of the Company.
Common stock shares outstanding percentage	1.00%
Percentage of payroll deductions				15.00%
Employee stock purchase plan offering period	6 months
Common stock fair market value percentage	85.00%
Share-based payment arrangement, expense		$ 400	$ 500
Number of common stock issued (in shares)		85,969

Leases - Narrative (Details) $ in Millions	1 Months Ended		12 Months Ended
Leases - Narrative (Details) $ in Millions	Aug. 31, 2022 USD ($) ft²	Feb. 28, 2018 USD ($) ft²	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Lease costs			$ 2.5	$ 2.3
Variable lease payments			0.7	0.9
Operating lease payments			$ 2.7	2.4
California
Lessee, Lease, Description [Line Items]
Leased premises under non cancelable operating lease \| ft²	12,456	32,974
Lease term	18 months	84 months
Period of base rent abatement		2 months
Base rent abated amount	$ 0.1	$ 0.2
Lease term extension period	3 years		7 years
Annual percentage increase to base rent	3.00%
California \| Minimum
Lessee, Lease, Description [Line Items]
Lease term extension notice period		12 months
California \| Maximum
Lessee, Lease, Description [Line Items]
Lease term extension notice period		9 months
California \| Other Non-current Assets
Lessee, Lease, Description [Line Items]
Refundable security deposit			$ 0.4	$ 0.4

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2022

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31,
	2022		2021
Prepaid research and development	$	3,421	$	2,819
Prepaid insurance	1,427		2,585
Prepaid licenses	959		819
Interest receivable	1,078		385
Other	173		156
Total prepaid expenses and other current assets	$	7,058	$	6,764

Financial Instruments - Narrative (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 0
Assets measured at fair value	0	$ 0
Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value	0	0
Fair Value, Recurring \| Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value		0
Fair Value Measurements, Non-recurring Basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value	0	0
Assets measured at fair value	$ 0	$ 0

Stock-Based Compensation - Equity Incentive Plan - Narrative (Details) - shares	1 Months Ended
	May 31, 2020	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance (in shares)		11,435,241	8,467,491
Shares of common stock available for future grants under the 2020 Stock Option and Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares outstanding percentage	5.00%
Total shares reserved for future issuance (in shares)		2,937,769	4,234,213
Exercise price as a percentage of estimated grant date fair value of shares	10.00%
Expiration period from date of grant	5 years
Shares of common stock available for future grants under the 2020 Stock Option and Incentive Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options under plan may be granted for periods	10 years
Exercise price as a percentage of estimated grant date fair value of shares	110.00%
Shares of common stock available for future issuance under the 2022 Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance (in shares)		1,000,000	0

Organization and Description of Business	12 Months Ended
Organization and Description of Business	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Pliant Therapeutics, Inc. (the “Company” or "Pliant" or “we” or “our” or “us”) is a clinical stage biopharmaceutical company focused on discovering and developing novel therapies for the treatment of fibrosis with an initial focus on treating fibrosis by inhibiting integrin-mediated activation of TGF-β. Fibrosis refers to the abnormal thickening and scarring of connective tissue due to the production and deposition of excess collagen in the extra-cellular matrix. Fibrosis can occur in many different tissues including lung, liver, kidney, muscle, skin and the GI tract, and often causes severe and debilitating disease leading to organ failure. The Company is located in South San Francisco, California, and was incorporated in the state of Delaware in June 2015. Public Offering In July 2022, the Company completed a public offering of 12,432,432 shares of common stock, including the exercise in full of the underwriters' option to purchase 1,621,621 additional shares of common stock. The shares were offered at a price of $18.50 per share, resulting in aggregate proceeds of approximately $215.4 million, net of underwriting discounts, commissions and offering expenses.

Commitments and Contingencies (Details)	12 Months Ended
Commitments and Contingencies (Details)	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Contractual arrangements cancellation period	30 days

Property and Equipment, net (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment, Net

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


	December 31,
	2022		2021
Laboratory equipment	$	9,581	$	7,947
Leasehold improvements	1,650		1,618
Construction-in-progress	66		38
Computer equipment and software	30		22
Total property and equipment	11,327		9,625
Less: Accumulated depreciation	(6,841)		(5,019)
Total property and equipment, net	$	4,486	$	4,606

Net Loss Per Share Attributable to Common Stockholders - Reconciliation of Numerator and Denominator Used in Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Numerator
Net loss	$ (123,321)	$ (97,263)
Net loss attributable to common stockholders	(123,321)	(97,263)
Net loss attributable to common stockholders	$ (123,321)	$ (97,263)
Weighted-average common shares outstanding used to calculate net loss per share attributable to common stockholders:
Basic (in shares)	42,015,908	35,846,421
Diluted (in shares)	42,015,908	35,846,421
Net loss per share, attributable to common stockholders:
Basic (USD per share)	$ (2.94)	$ (2.71)
Diluted (USD per share)	$ (2.94)	$ (2.71)

Novartis Collaboration and License Agreement (the "Novartis Agreement") - Additional Information (Details) - Novartis	12 Months Ended			48 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2019 USD ($) research	Dec. 31, 2022 USD ($)
Novartis Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from upfront non-refundable license fee			$ 50,000,000
Revenue recognized from related party		$ 7,600,000
Receivable from related party transactions	$ 2,000,000	2,000,000		$ 2,000,000
Contract assets	0	0		0
Contract liabilities	0	$ 0		0
Novartis Agreement \| Achievement of First Patient Dosing Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Due from related parties	4,000,000			4,000,000
Revenue recognized from related party				$ 29,000,000
Novartis Agreement \| Research and Development
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue recognized from related party	9,700,000
Novartis Agreement \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Number of Integrin research targets \| research			3
Collaboration and license agreement, integrin research targets amount (up to)			$ 416,000,000
Amount remaining for achievement	387,000,000
Novartis Agreement RD For PLN-1474
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transaction price of Novartis agreement	20,000,000		20,000,000
Novartis Agreement RD For Integrin Research Targets \| Research and Development
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transaction price of Novartis agreement	$ 18,400,000		$ 18,400,000

Common Stock (Tables)

12 Months Ended

Dec. 31, 2022

Equity [Abstract]

Schedule of Shares Reserved for Future Issuance

Shares reserved for future issuance


	December 31,
	2022	2021
Outstanding stock option awards	5,569,567	3,620,180
Vesting of RSUs	507,925	—
Vesting of PSUs*	531,796	—
Shares of common stock available for future grants under the 2020 Stock Option and Incentive Plan	2,937,769	4,234,213
Shares of common stock available for future issuance under the 2020 Employee Stock Purchase Plan	888,184	613,098
Shares of common stock available for future issuance under the 2022 Inducement Plan	1,000,000	—
Total shares reserved for future issuance	11,435,241	8,467,491
*PSUs granted and outstanding based on target level of achievement of 100%.

Income Taxes - Summary of Net Operating Losses and Tax Credit Carry Forwards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Federal
Operating Loss Carryforwards [Line Items]
Tax credits	$ 20,193
Federal \| Starting from January 1, 2018
Operating Loss Carryforwards [Line Items]
Net operating losses	190,697
Federal \| Before January 1, 2018
Operating Loss Carryforwards [Line Items]
Net operating losses	$ 29,486
Federal \| Earliest Tax Year
Operating Loss Carryforwards [Line Items]
Net operating losses, Expiration year	2035
Federal \| Latest Tax Year
Operating Loss Carryforwards [Line Items]
Net operating losses, Expiration year	2037
State
Operating Loss Carryforwards [Line Items]
Net operating losses	$ 278,930
Tax credits	$ 5,587
State \| Earliest Tax Year
Operating Loss Carryforwards [Line Items]
Net operating losses, Expiration year	2035
Tax credits Expiration year	2036
State \| Latest Tax Year
Operating Loss Carryforwards [Line Items]
Net operating losses, Expiration year	2042
Tax credits Expiration year	2042

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Commitments The Company has contractual arrangements with research and development organizations and suppliers; however, these contracts are generally cancellable on 30 days’ notice and the obligations under these contracts are largely based on services performed. License and Collaboration Agreements Potential payments related to the Company’s license and research agreements, including milestone and royalty payments, are detailed in Note 8. Legal Proceedings From time to time, the Company may become involved in legal proceedings arising from the ordinary course of business. The Company record a liability for such matters when it is probable that future losses will be incurred and that such losses can be reasonably estimated. Significant judgment by us is required to determine both probability and the estimated amount. Management is currently not aware of any legal matters that could have a material adverse effect on our financial position, results of operations or cash flows. Indemnification In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance.

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Auditor Information [Abstract]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	San Francisco, California

Income Taxes - Summary of Reconciliation of U.S. Federal Statutory Income Tax Rate to Company’s Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income tax computed at federal statutory rate	21.00%	21.00%
State taxes, net of federal tax benefit	7.30%	7.70%
General business credit—federal	3.60%	5.30%
Stock-based compensation	(1.00%)	(0.70%)
Other permanent differences	(0.40%)	(0.10%)
Change in valuation allowance	(30.50%)	(33.20%)
Effective income tax rate	0.00%	0.00%

Related Party Transactions - (Details) - Outstanding stock option awards - Third Rock Ventures - Non-employee Director - USD ($) $ in Millions	1 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Related Party Transaction [Line Items]
Options granted (in shares)	15,000	26,572
Grant date fair value of stock option	$ 0.1	$ 0.5
Vesting rights, percentage	25.00%	25.00%

Debt (Tables)

12 Months Ended

Dec. 31, 2022

Debt Disclosure [Abstract]

Schedule of Maturities of Long-Term Debt

Future maturities of debt as of December 31, 2022 are as follows (in thousands):


	As of December 31, 2022
2023	$	—
2024	—
2025	—
2026	5,455
2027	4,545
Thereafter	$	—
Total	$	10,000
Less: unamortized debt issuance costs	(133)
Accretion of final payment	62
Total	$	9,929

Stock-Based Compensation - Summary of Classification of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	$ 22,598	$ 10,437
Research and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	8,730	3,928
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	13,867	6,509
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	36	182
Stock options and ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	13,280	10,255
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	1,892	0
Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Payment Arrangement, Expense	$ 7,390	$ 0

Debt - Schedule of Maturities of Long-Term Debt (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
2023	$ 0
2024	0
2025	0
2026	5,455,000
2027	4,545,000
Thereafter	0
Total	10,000,000	$ 0
Less: unamortized debt issuance costs	(133,000)
Accretion of final payment	62,000
Total	$ 9,929,000	$ 0

Leases

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Leases

On January 1, 2021, the Company adopted ASC 842 and the following disclosures as of and for the years ended December 31, 2022 and 2021 are presented under ASC 842.

In February 2018, the Company entered into a non-cancelable lease agreement (the “Lease”) for premises consisting of approximately 32,974 square feet located in South San Francisco, California (the “Premises”). The Company moved into the Premises in July 2018. The Premises is being used for the Company’s corporate headquarters and principal operating facility. The term of the Lease is eighty-four months, which commenced on July 1, 2018. Base rent was abated for the first two months of the lease term and thereafter is $0.2 million per month during the first year of the lease term, with specified annual increases thereafter. The Company paid a refundable security deposit of approximately $0.4 million, which is included in other non-current assets in the Balance Sheets at December 31, 2022 and 2021. The Company has the right to extend the lease term by seven years upon written notice not more than twelve months nor less than nine months prior to the expiration of the original lease term, with monthly payments equal to the “fair rental value” as defined in the Lease. The exercise of lease renewal options is at the sole discretion of the Company and is not included in the ROU asset and lease liability as it is not reasonably certain of exercise. This lease does not contain material variable rent payments, residual value guarantees, covenants, or other restrictions.

In August 2022, the Company entered into a non-cancelable lease agreement for premises consisting of approximately 12,456 square feet located in South San Francisco, California. The premises is being used as additional office space for the Company. The term of the lease is 18 months, which commenced on August 1, 2022. Base rent is $0.1 million per month during the first year of the lease term, with specified annual increases of 3% thereafter. The Company has the right to extend the lease term by 3 years with monthly payments equal to the market rate of rent. The exercise of lease renewal options is at the sole discretion of the Company and is not included in the right-of-use (ROU) asset and lease liability as it is not reasonably certain of exercise. This lease does not contain material variable rent payments, residual value guarantees, covenants, or other restrictions.

For the years ended December 31, 2022 and 2021, the Company recognized expenses associated with the operating leases of $2.5 million and $2.3 million, respectively. Additionally for those same years, the Company incurred variable lease costs of $0.7 million and $0.9 million, respectively, which is comprised primarily of the Company's proportionate share of operating expenses, property taxes, and insurance. Short-term lease expense and variable lease payments recorded in operating expenses were immaterial for the years ended December 31, 2022 and 2021. For the years ended December 31, 2022 and 2021, cash paid for amounts included in the measurement of operating lease liabilities was $2.7 million and $2.4 million, respectively.

The undiscounted future non-cancellable lease payments of the Company's operating lease liability as of December 31, 2022 were as follows (in thousands):


Year ending December 31:	Operating Leases
2023	$	2,836
2024	2,422
2025	1,202
2026	—
2027	—
Total lease payments	$	6,460
Less: Present value discount	574
Total current operating lease liabilities	$	2,457
Total non-current operating lease liabilities	$	3,429

The weighted-average remaining lease terms and discount rates related to the Company's operating leases were as follows:


	As of December 31,
	2022		2021
Weighted-average remaining lease term (in years)	2.30		3.40
Weighted-average discount rate	8.20	%	7.9	%

Property and Equipment, net - Schedule of Property and Equipment Net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 11,327	$ 9,625
Less: Accumulated depreciation	(6,841)	(5,019)
Total property and equipment, net	4,486	4,606
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	9,581	7,947
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	1,650	1,618
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property and equipment	66	38
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 30	$ 22

Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

Summary of Money Market Funds, U.S. Government Agency Securities and Corporate Debt Securities by Significant Investment Category

The following tables show the Company’s cash and cash equivalents and short-term investments by significant investment category as of December 31, 2022 and 2021 (in thousands):


	As of December 31, 2022
	Adjusted Cost		Unrealized Gains		Unrealized Losses		Market Value
Level 1:
Money Market Funds	$	28,312	$	—	$	—	$	28,312
Level 2:
U.S. Treasury securities included in cash and cash equivalents and short-term investments	4,446		—		(5)		4,441
U.S. government agency securities included in short-term investments	28,746		—		(111)		28,635
Corporate debt securities included in cash and cash equivalents and short-term investments	266,267		45		(1,887)		264,425
Total financial assets	$	327,771	$	45	$	(2,003)	$	325,813


	As of December 31, 2021
	Adjusted Cost		Unrealized Gains		Unrealized Losses		Market Value
Level 1:
Money Market Funds	$	15,329	$	—	$	—	$	15,329
Level 2:
U.S. government agency securities included in short-term investments	5,003		—		—		5,003
Corporate debt securities included in cash and cash equivalents and short-term investments	163,626		1		(202)		163,425
Total financial assets	$	183,958	$	1	$	(202)	$	183,757

Summery of Remaining Contractual Maturities of Company’s Short-term Investments

The following summarizes the remaining contractual maturities of the Company’s short-term investments as of December 31, 2022:


	Adjusted Cost		Market Value
Mature in 1 year or less	$	252,238	$	250,682
Mature in 1 to 2 years	47,222		46,820
Total	$	299,460	$	297,502

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	48,941,254	36,083,301
Common stock, shares outstanding (in shares)	48,941,254	36,083,301

Income Taxes - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating losses	$ 65,689	$ 51,554
Research and development credits	19,688	13,989
Accrued expenses	387	292
Other	1,706	775
Capitalized research and development	13,900	0
Lease liability	1,638	2,000
Stock based compensation	5,073	1,816
Total deferred tax assets	108,081	70,426
Deferred tax liabilities:
Fixed asset basis	(258)	(61)
Prepaid expenses	(630)	(921)
Right of use asset	(1,509)	(1,760)
Total deferred tax liabilities	(2,397)	(2,742)
Valuation allowance	105,684	67,684	$ 35,441
Net deferred taxes	$ 0	$ 0

Novartis Collaboration and License Agreement ("the Novartis Agreement") - Performance Obligation (Details) - Novartis - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 - Novartis Agreement RD For Integrin Research Targets $ in Millions	Dec. 31, 2022 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1.4
Revenue, remaining performance obligation, expected timing of satisfaction	1 year

Financial Instruments - Summary of Cash and Cash Equivalents, Money Market Funds and Short-term Investments by Significant Investment Category (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	$ 327,771	$ 183,958
Unrealized Gains	45	1
Unrealized Losses	(2,003)	(202)
Market Value	325,813	183,757
Level 1 \| Money Market Funds
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	28,312	15,329
Unrealized Gains	0	0
Unrealized Losses	0	0
Market Value	28,312	15,329
Level 2 \| Corporate debt securities included in cash and cash equivalents and short-term investments
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	266,267	163,626
Unrealized Gains	45	1
Unrealized Losses	(1,887)	(202)
Market Value	264,425	163,425
Level 2 \| U.S. Treasury securities included in cash and cash equivalents and short-term investments
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	4,446
Unrealized Gains	0
Unrealized Losses	(5)
Market Value	4,441
Level 2 \| U.S. government agency securities included in short-term investments
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	28,746	5,003
Unrealized Gains	0	0
Unrealized Losses	(111)	0
Market Value	$ 28,635	$ 5,003

Common Stock - Schedule of Shares Reserved for Future Issuance (Details) - shares	Dec. 31, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	11,435,241	8,467,491
Shares of common stock available for future grants under the 2020 Stock Option and Incentive Plan
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	2,937,769	4,234,213
Shares of common stock available for future issuance under the 2020 Employee Stock Purchase Plan
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	888,184	613,098
Shares of common stock available for future issuance under the 2022 Inducement Plan
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	1,000,000	0
Outstanding stock option awards
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	5,569,567	3,620,180
Restricted stock units
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	507,925	0
Performance Stock Units
Class of Stock [Line Items]
Total shares reserved for future issuance (in shares)	531,796	0
Performance-based restricted stock units
Class of Stock [Line Items]
Target level of achievement percentage	100.00%