Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”).
Reclassification	Reclassification Certain prior year amounts in the Company’s consolidated statements of operations and comprehensive loss have been reclassified to conform to the current year presentation. Specifically, interest expense is disclosed separately on the Company’s consolidated statements of operations and comprehensive loss, which had no impact on reported net loss, comprehensive loss, or loss per share.
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include but are not limited to accrued research and development expenses and to the fair value of stock options. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.
Foreign Currencies	Foreign Currencies Certain transactions during the year ended December 31, 2022 and 2021 were denominated in currencies other than the U.S. dollar. Gains and losses from foreign currency transactions were not material for all periods presented and are reflected in the consolidated statements of operations and comprehensive loss as a component of interest income and other, net. The Company’s subsidiary in Lithuania uses the Euro as its functional currency for financial reporting. The re-measurement from Euros to U.S. dollars results in translation gain and loss adjustments, which are reflected as a component of comprehensive loss as foreign currency translation adjustments.
Fair Value Measurements	Fair Value Measurements Financial assets and liabilities are recorded at fair value on a recurring basis in the consolidated balance sheets. The carrying values of Company’s financial assets and liabilities, including cash and cash equivalents, restricted cash, prepaid and other current assets, accounts payable, and accrued expenses approximate to their fair value due to the short-term nature of these instruments. The fair value of the Company’s term loan approximates its carrying value, or amortized cost, due to the prevailing market rates of interest rates it bears. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. Assets and liabilities recorded at fair value are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels are directly related to the amount of subjectivity with the inputs to the valuation of these assets or liabilities as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable inputs for similar assets or liabilities. These include quoted prices for identical or similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; and Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash and cash equivalents and short-term available-for-sale securities. Bank deposits are held by accredited financial institutions and these deposits may at times be in excess of insured limits. The Company limits its credit risk associated with cash and cash equivalents by placing them with financial institutions that it believes are of high quality. The Company has not experienced any losses on its deposits of cash or cash equivalents. The Company limits amounts invested in available-for-sale securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company is not exposed to any significant concentrations of credit risk from these financial instruments.
Other Risks and Uncertainties	Other Risks and Uncertainties The Company’s future results of operations involve a number of 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, the Company’s early stages of clinical drug development; the Company’s ability to advance product candidates into, and successfully complete, clinical trials on the timelines it projects; the Company’s ability to adequately demonstrate sufficient safety and efficacy of its product candidates; the Company’s ability to enroll patients in its ongoing and future clinical trials; the Company’s ability to successfully manufacture and supply its product candidates for clinical trials; the Company’s ability to obtain additional capital to finance its operations; uncertainties related to the projections of the size of patient populations suffering from the diseases the Company is targeting; the Company’s ability to obtain, maintain, and protect its intellectual property rights; developments relating to the Company’s competitors and its industry, including competing product candidates and therapies; general economic and market conditions; and other risks and uncertainties. The Company’s product candidates will require approvals from the U.S. Food and Drug Administration 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 is denied approval, approval is delayed or the Company is unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company. The ongoing COVID-19 pandemic has disrupted and may continue to disrupt the Company’s business and delay its preclinical and clinical programs and timelines. The extent to which the COVID-19 pandemic may impact the Company’s future operating results and financial condition is uncertain.
Segment Reporting	Segment Reporting The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of allocating resources and evaluating financial performance.
Cash and Cash Equivalents	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 and commercial paper that are stated at fair value.
Investments	Investments Investments have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its available-for-sale investments in debt securities at the time of purchase. Generally, investments with original maturities beyond three months at the date of purchase are classified as short-term because it is management’s intent to use the investments to fund current operations or to make them available for current operations. Unrealized gains and losses are excluded from net loss and are reported as a component of comprehensive loss. The Company periodically evaluates whether declines in fair values of its available-for-sale securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the available-for-sale security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any available-for-sale securities before recovery of its amortized cost basis. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest income and other, net. The cost of investments sold is based on the specific-identification method. The Company has not experienced any material realized gains or losses or other-than-temporary losses in the periods presented.
Leases	Leases The Company is a lessee in noncancellable operating leases for office space. Beginning in 2022, the Company accounts for leases in accordance with Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842). The Company determines if an arrangement is a lease or contains an embedded lease at inception. The Company accounts for a contract as a lease when it has the right to control the asset for a period of time while obtaining substantially all of the asset’s economic benefits. For arrangements that meet the definition of a lease, the Company determines the initial classification and measurement of its right-of-use (“ROU”) asset and lease liability at the lease commencement date and thereafter if modified. Operating lease ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make the contractual lease payments over the lease term. The ROU asset is initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred less any lease incentives received. The operating lease liability is initially measured at the present value of the unpaid lease payments at the lease commencement date. The lease liability is subsequently measured at amortized cost using the effective-interest method. The lease term includes any renewal options that the Company is reasonably assured to exercise. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable, otherwise, the Company uses its estimated collateralized incremental borrowing rate for the lease term. The Company has elected not to record leases with an original term of twelve months or less on its consolidated balance sheets and recognizes those lease payments in operating expenses in the consolidated statements of operations and comprehensive loss. The Company’s short-term lease is not material. In addition, the Company’s leases may require it to pay additional costs, such as utilities, maintenance, and other operating costs, which are generally referred to as non-lease components and vary based on future outcomes. The Company has elected to not separate lease and non-lease components. Only the fixed costs for lease components and their associated non-lease components are accounted for as a single lease component and recognized as part of a ROU asset and lease liability. Any variable expenses are recognized in operating expenses as incurred. Rent expense for an operating lease liability is recognized on a straight-line basis over the lease term and is included in operating expenses in the consolidated statements of operations and comprehensive loss.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at cost, less accumulated depreciation. Depreciation is calculated on a straight-line basis over the estimated useful lives of the related assets, generally ranging from three to seven years. Leasehold improvements are amortized on a straight-line basis over the shorter of the assets’ estimated useful life or the remaining term of the lease. Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the consolidated balance sheets and the resulting gains or losses are recorded in the consolidated statements of operations and comprehensive loss. Maintenance and repair costs are expensed as incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company periodically evaluates its long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets or group of assets may not be fully recoverable. If indicators of impairment exist and the undiscounted future cash flows that the assets are expected to generate are less than the carrying value of the assets, then the Company will reduce the carrying amount of the assets through an impairment charge, to their estimated fair values based on a discounted cash flow approach or, when available and appropriate, to comparable market values. There were no such indicators for the periods presented.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company estimates preclinical and clinical study 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. The Company records the costs of research and development activities based upon the estimated services provided but not yet invoiced and includes these costs in accrued expenses in the consolidated balance sheets. These costs are a component of the Company’s research and development expenses. The Company accrues for these costs based on factors such as estimates of the work completed in accordance with agreements established with its third-party service providers. The Company makes judgments and estimates in determining the accrued expenses balance. As actual costs become known, the Company adjusts its accrued expenses. The Company has not experienced any material differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accrued expenses could materially affect the Company’s results of operations. Contingent milestone payments, if any, are expensed when the milestone results are probable and estimable, which is generally upon achievement of the milestone.
Warrants To Purchase Common Stock	Warrants to Purchase Common Stock The Company classifies warrants indexed to its common stock and meeting the requirements for equity classification within stockholders’ equity. This assessment is conducted at the time of warrant issuance and as of each reporting period that the warrants remain outstanding.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist primarily of costs incurred for the development of the Company’s lead product candidate, pegozafermin. Research and development expenses consist primarily of external costs related to preclinical and clinical development and related supplies and personnel costs. Personnel costs consist of salaries, employee benefits and stock-based compensation for individuals involved in research and development efforts. Payments associated with agreements to acquire licenses to develop, use, manufacture and commercialize products and purchases of pegozafermin from contract manufacturing organizations that have not reached technological feasibility and do not have alternate future commercial use are expensed as incurred.
Stock-Based Compensation	Stock-Based Compensation The Company provides equity awards in the form of stock options and restricted stock units. The Company measures its equity awards made to employees, directors, and non-employee service providers based on estimated fair values and recognizes stock-based compensation over the requisite service period. The Company accounts for forfeitures as they occur. The Company estimates the fair value of stock option awards on the date of grant using a Black-Scholes option pricing model. The Company recognizes compensation for the value of stock options awards, which have graded vesting, using the straight-line method over the requisite service period of each award. The Black-Scholes option pricing model requires a number of assumptions, of which the most significant are expected volatility, expected option term (the time from the grant date until the options are exercised or expire), risk-free rate, and expected dividend rate. These assumptions include: • Expected volatility—Since the Company has limited trading history for its common stock, expected volatility is estimated based on weighting the Company’s volatility and the volatility of comparable publicly traded biotechnology companies during the equivalent period of the calculated expected term of the options granted. The comparable companies were chosen based on their similar size, stage in the life cycle, or area of specialty. There is a degree of uncertainty in determining a comparable peer group as each of the peers are engaged in varied research and development activities, the timing and progress of which differ within the peer group. • Expected term—The expected term of options granted to employees and directors is determined using the “simplified” method. Under this approach, the expected term is presumed to be the midpoint between the weighted-average vesting term and the contractual term of the option. The simplified method makes the assumption that the employee will exercise stock options evenly over the period when the stock options are vested and ending on the date when the stock options would expire. The expected option term for options granted to non-employees is estimated on a grant-by-grant basis. • Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury zero coupon bonds in effect on the grant date for periods with an equivalent expected term as the option. • Expected dividend—The Company has never paid dividends and has no foreseeable plans to pay dividends on its shares of common stock. Therefore, an expected dividend of zero is used. The fair value of restricted stock units is based on the fair value of the Company’s common stock on the date of grant. The grant date fair value of restricted stock units with service vesting conditions is recognized over the requisite service period on a straight-line basis. For restricted stock units with performance vesting conditions, the Company evaluates the probability of achieving the performance condition at each reporting date and recognizes expense for such performance awards over the requisite service period using the accelerated attribution method.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statements carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be realized. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income or loss in the period that includes the enactment date. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. Interest and penalties related to unrecognized tax benefits are included within the provision of income tax.
Basic and Diluted Net Loss per Share	Basic and Diluted Net Loss per Share Basic loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding together with the number of additional shares of common stock that would have been outstanding if all potentially dilutive shares of common stock had been issued. Since the Company is in a loss position for the periods presented, basic net loss per share is the same as diluted net loss per share since the effects of potentially dilutive securities are antidilutive. Shares of the Company’s common stock underlying pre-funded warrants exercisable for nominal consideration are included in the computation of basic and diluted net loss per share, even if antidilutive.
Comprehensive Loss	Comprehensive Loss The Company’s comprehensive loss is comprised of net loss and changes in unrealized gains or losses on available-for-sale securities and foreign currency translation adjustments.
Recent Accounting Pronouncements	Recently Adopted Accounting Standards In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842), or Accounting Standards Codification (“ASC”) 842, which requires lessees to recognize leases on the balance sheet and disclose key information about leasing arrangements. ASC 842 establishes a ROU model that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases are classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. On January 1, 2022, the Company adopted ASC 842 using the modified retrospective transition method and elected the practical expedients to not reassess whether any expired or existing contracts are or contain leases, carry forward its historical lease classification and not reassess initial direct costs for existing leases. Upon adoption of ASC 842, the Company recorded an operating ROU asset of $0.2 million and an operating lease liability of $0.2 million on its consolidated balance sheet. There was no adjustment to the opening balance of accumulated deficit as a result of adoption. Results for the year ended December 31, 2022 are presented under ASC 842. Prior period amounts preceding January 1, 2022 continue to be reported in accordance with the Company’s historical accounting under the previous lease guidance, ASC 840. Recent Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which replaces the existing incurred loss impairment model with an expected credit loss model and requires a financial asset measured at amortized cost to be presented at the net amount expected to be collected. As an emerging growth company, ASU 2016-13 is effective for the Company for the year ending December 31, 2023 and interim periods within that fiscal year and must be adopted using a modified retrospective approach, with certain exceptions. The Company is evaluating the impact of this standard and does not expect the adoption of ASU 2016-13 to have a material impact on the Company’s consolidated financial statements and related disclosures.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”).

Reclassification

Certain prior year amounts in the Company’s consolidated statements of operations and comprehensive loss have been reclassified to conform to the current year presentation. Specifically, interest expense is disclosed separately on the Company’s consolidated statements of operations and comprehensive loss, which had no impact on reported net loss, comprehensive loss, or loss per share.

Principles of Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include but are not limited to accrued research and development expenses and to the fair value of stock options. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could differ from those estimates.

Foreign Currencies

Certain transactions during the year ended December 31, 2022 and 2021 were denominated in currencies other than the U.S. dollar. Gains and losses from foreign currency transactions were not material for all periods presented and are reflected in the consolidated statements of operations and comprehensive loss as a component of interest income and other, net. The Company’s subsidiary in Lithuania uses the Euro as its functional currency for financial reporting. The re-measurement from Euros to U.S. dollars results in translation gain and loss adjustments, which are reflected as a component of comprehensive loss as foreign currency translation adjustments.

Fair Value Measurements

Financial assets and liabilities are recorded at fair value on a recurring basis in the consolidated balance sheets. The carrying values of Company’s financial assets and liabilities, including cash and cash equivalents, restricted cash, prepaid and other current assets, accounts payable, and accrued expenses approximate to their fair value due to the short-term nature of these instruments. The fair value of the Company’s term loan approximates its carrying value, or amortized cost, due to the prevailing market rates of interest rates it bears. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. Assets and liabilities recorded at fair value are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels are directly related to the amount of subjectivity with the inputs to the valuation of these assets or liabilities as follows:

Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable inputs for similar assets or liabilities. These include quoted prices for identical or similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; and

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

Concentrations of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash and cash equivalents and short-term available-for-sale securities. Bank deposits are held by accredited financial institutions and these deposits may at times be in excess of insured limits. The Company limits its credit risk associated with cash and cash equivalents by placing them with financial institutions that it believes are of high quality. The Company has not experienced any losses on its deposits of cash or cash equivalents. The Company limits amounts invested in available-for-sale securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company is not exposed to any significant concentrations of credit risk from these financial instruments.

Other Risks and Uncertainties

The Company’s future results of operations involve a number of 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, the Company’s early stages of clinical drug development; the Company’s ability to advance product candidates into, and successfully complete, clinical trials on the timelines it projects; the Company’s ability to adequately demonstrate sufficient safety and efficacy of its product candidates; the Company’s ability to enroll patients in its ongoing and future clinical trials; the Company’s ability to successfully manufacture and supply its product candidates for clinical trials; the Company’s ability to obtain additional capital to finance its operations; uncertainties related to the projections of the size of patient populations suffering from the diseases the Company is targeting; the Company’s ability to obtain, maintain, and protect its intellectual property rights; developments relating to the Company’s competitors and its industry, including competing product candidates and therapies; general economic and market conditions; and other risks and uncertainties.

The Company’s product candidates will require approvals from the U.S. Food and Drug Administration 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 is denied approval, approval is delayed or the Company is unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

The ongoing COVID-19 pandemic has disrupted and may continue to disrupt the Company’s business and delay its preclinical and clinical programs and timelines. The extent to which the COVID-19 pandemic may impact the Company’s future operating results and financial condition is uncertain.

Segment Reporting

The Company has one operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a consolidated basis for the purposes of allocating resources and evaluating financial performance.

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 and commercial paper that are stated at fair value.

Investments

Investments have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its available-for-sale investments in debt securities at the time of purchase. Generally, investments with original maturities beyond three months at the date of purchase are classified as short-term because it is management’s intent to use the investments to fund current operations or to make them available for current operations.

Unrealized gains and losses are excluded from net loss and are reported as a component of comprehensive loss. The Company periodically evaluates whether declines in fair values of its available-for-sale securities below their book value are other-than-temporary. This evaluation consists of several qualitative and quantitative factors regarding the severity and duration of the unrealized loss as well as the Company’s ability and intent to hold the available-for-sale security until a forecasted recovery occurs. Additionally, the Company assesses whether it has plans to sell the security or it is more likely than not it will be required to sell any available-for-sale securities before recovery of its amortized cost basis. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest income and other, net. The cost of investments sold is based on the specific-identification method. The Company has not experienced any material realized gains or losses or other-than-temporary losses in the periods presented.

Leases

The Company is a lessee in noncancellable operating leases for office space. Beginning in 2022, the Company accounts for leases in accordance with Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842). The Company determines if an arrangement is a lease or contains an embedded lease at inception. The Company accounts for a contract as a lease when it has the right to control the asset for a period of time while obtaining substantially all of the asset’s economic benefits. For arrangements that meet the definition of a lease, the Company determines the initial classification and measurement of its right-of-use (“ROU”) asset and lease liability at the lease commencement date and thereafter if modified. Operating lease ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make the contractual lease payments over the lease term. The ROU asset is initially measured at cost, which comprises the initial amount of the lease liability adjusted for lease payments made at or before the lease commencement date, plus any initial direct costs incurred less any lease incentives received. The operating lease liability is initially measured at the present value of the unpaid lease payments at the lease commencement date. The lease liability is subsequently measured at amortized cost using the effective-interest method. The lease term includes any renewal options that the Company is reasonably assured to exercise. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable, otherwise, the Company uses its estimated collateralized incremental borrowing rate for the lease term. The Company has elected not to record leases with an original term of twelve months or less on its consolidated balance sheets and recognizes those lease payments in operating expenses in the consolidated statements of operations and comprehensive loss. The Company’s short-term lease is not material.

In addition, the Company’s leases may require it to pay additional costs, such as utilities, maintenance, and other operating costs, which are generally referred to as non-lease components and vary based on future outcomes. The Company has elected to not separate lease and non-lease components. Only the fixed costs for lease components and their associated non-lease components are accounted for as a single lease component and recognized as part of a ROU asset and lease liability. Any variable expenses are recognized in operating expenses as incurred. Rent expense for an operating lease liability is recognized on a straight-line basis over the lease term and is included in operating expenses in the consolidated statements of operations and comprehensive loss.

Property and Equipment, Net

Property and equipment are stated at cost, less accumulated depreciation. Depreciation is calculated on a straight-line basis over the estimated useful lives of the related assets, generally ranging from three to seven years. Leasehold improvements are amortized on a straight-line basis over the shorter of the assets’ estimated useful life or the remaining term of the lease. Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the consolidated balance sheets and the resulting gains or losses are recorded in the consolidated statements of operations and comprehensive loss. Maintenance and repair costs are expensed as incurred.

Impairment of Long-Lived Assets

The Company periodically evaluates its long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets or group of assets may not be fully recoverable. If indicators of impairment exist and the undiscounted future cash flows that the assets are expected to generate are less than the carrying value of the assets, then the Company will reduce the carrying amount of the assets through an impairment charge, to their estimated fair values based on a discounted cash flow approach or, when available and appropriate, to comparable market values. There were no such indicators for the periods presented.

Accrued Research and Development Expenses

The Company estimates preclinical and clinical study 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. The Company records the costs of research and development activities based upon the estimated services provided but not yet invoiced and includes these costs in accrued expenses in the consolidated balance sheets. These costs are a component of the Company’s research and development expenses.

The Company accrues for these costs based on factors such as estimates of the work completed in accordance with agreements established with its third-party service providers. The Company makes judgments and estimates in determining the accrued expenses balance. As actual costs become known, the Company adjusts its accrued expenses. The Company has not experienced any material differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accrued expenses could materially affect the Company’s results of operations. Contingent milestone payments, if any, are expensed when the milestone results are probable and estimable, which is generally upon achievement of the milestone.

Warrants To Purchase Common Stock

Warrants to Purchase Common Stock

The Company classifies warrants indexed to its common stock and meeting the requirements for equity classification within stockholders’ equity. This assessment is conducted at the time of warrant issuance and as of each reporting period that the warrants remain outstanding.

Research and Development Expenses

Research and development expenses consist primarily of costs incurred for the development of the Company’s lead product candidate, pegozafermin. Research and development expenses consist primarily of external costs related to preclinical and clinical development and related supplies and personnel costs. Personnel costs consist of salaries, employee benefits and stock-based compensation for individuals involved in research and development efforts. Payments associated with agreements to acquire licenses to develop, use, manufacture and commercialize products and purchases of pegozafermin from contract manufacturing organizations that have not reached technological feasibility and do not have alternate future commercial use are expensed as incurred.

Stock-Based Compensation

The Company provides equity awards in the form of stock options and restricted stock units. The Company measures its equity awards made to employees, directors, and non-employee service providers based on estimated fair values and recognizes stock-based compensation over the requisite service period. The Company accounts for forfeitures as they occur.

The Company estimates the fair value of stock option awards on the date of grant using a Black-Scholes option pricing model. The Company recognizes compensation for the value of stock options awards, which have graded vesting, using the straight-line method over the requisite service period of each award.

The Black-Scholes option pricing model requires a number of assumptions, of which the most significant are expected volatility, expected option term (the time from the grant date until the options are exercised or expire), risk-free rate, and expected dividend rate. These assumptions include:

•

Expected volatility—Since the Company has limited trading history for its common stock, expected volatility is estimated based on weighting the Company’s volatility and the volatility of comparable publicly traded biotechnology companies during the equivalent period of the calculated expected term of the options granted. The comparable companies were chosen based on their similar size, stage in the life cycle, or area of specialty. There is a degree of uncertainty in determining a comparable peer group as each of the peers are engaged in varied research and development activities, the timing and progress of which differ within the peer group.

•

Expected term—The expected term of options granted to employees and directors is determined using the “simplified” method. Under this approach, the expected term is presumed to be the midpoint between the weighted-average vesting term and the contractual term of the option. The simplified method makes the assumption that the employee will exercise stock options evenly over the period when the stock options are vested and ending on the date when the stock options would expire. The expected option term for options granted to non-employees is estimated on a grant-by-grant basis.

•

Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury zero coupon bonds in effect on the grant date for periods with an equivalent expected term as the option.

•

Expected dividend—The Company has never paid dividends and has no foreseeable plans to pay dividends on its shares of common stock. Therefore, an expected dividend of zero is used.

The fair value of restricted stock units is based on the fair value of the Company’s common stock on the date of grant. The grant date fair value of restricted stock units with service vesting conditions is recognized over the requisite service period on a straight-line basis. For restricted stock units with performance vesting conditions, the Company evaluates the probability of achieving the performance condition at each reporting date and recognizes expense for such performance awards over the requisite service period using the accelerated attribution method.

Income Taxes

Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statements carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be realized. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income or loss in the period that includes the enactment date. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. Interest and penalties related to unrecognized tax benefits are included within the provision of income tax.

Basic and Diluted Net Loss per Share

Basic loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding together with the number of additional shares of common stock that would have been outstanding if all potentially dilutive shares of common stock had been issued. Since the Company is in a loss position for the periods presented, basic net loss per share is the same as diluted net loss per share since the effects of potentially dilutive securities are antidilutive. Shares of the Company’s common stock underlying pre-funded warrants exercisable for nominal consideration are included in the computation of basic and diluted net loss per share, even if antidilutive.

Comprehensive Loss

The Company’s comprehensive loss is comprised of net loss and changes in unrealized gains or losses on available-for-sale securities and foreign currency translation adjustments.

Recent Accounting Pronouncements

Recently Adopted Accounting Standards

In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842), or Accounting Standards Codification (“ASC”) 842, which requires lessees to recognize leases on the balance sheet and disclose key information about leasing arrangements. ASC 842 establishes a ROU model that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. Leases are classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement.

On January 1, 2022, the Company adopted ASC 842 using the modified retrospective transition method and elected the practical expedients to not reassess whether any expired or existing contracts are or contain leases, carry forward its historical lease classification and not reassess initial direct costs for existing leases. Upon adoption of ASC 842, the Company recorded an operating ROU asset of $0.2 million and an operating lease liability of $0.2 million on its consolidated balance sheet. There was no adjustment to the opening balance of accumulated deficit as a result of adoption. Results for the year ended December 31, 2022 are presented under ASC 842. Prior period amounts preceding January 1, 2022 continue to be reported in accordance with the Company’s historical accounting under the previous lease guidance, ASC 840.

Recent Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which replaces the existing incurred loss impairment model with an expected credit loss model and requires a financial asset measured at amortized cost to be presented at the net amount expected to be collected. As an emerging growth company, ASU 2016-13 is effective for the Company for the year ending December 31, 2023 and interim periods within that fiscal year and must be adopted using a modified retrospective approach, with certain exceptions. The Company is evaluating the impact of this standard and does not expect the adoption of ASU 2016-13 to have a material impact on the Company’s consolidated financial statements and related disclosures.