PLIANT THERAPEUTICS, INC. 10-K

Item 8. Financial Statements and Supplementary Data. INDEX TO FINANCIAL STATEMENTS Report of Independent Registered Public Accounting Firm (PCAOB ID No. 34 ) 87 Balance Sheets 89 Statements of Operations and Comprehensive Gain ( Loss ) 90 Statements of Stockholders’ Equity 91 Statements of Cash Flows 92 Notes to Financial Statements 93 86 REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the stockholders and the Board of Directors of Pliant Therapeutics, Inc. Opinion on the Financial Statements We have audited the accompanying balance sheets of Pliant Therapeutics, Inc. (the "Company") as of December 31, 2023 and 2022, the related statements of operations and comprehensive loss, stockholders’ equity, and cash flows, for each of the three years in the period ended December 31, 2023, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America. We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 27, 2024, expressed an unqualified opinion on the Company's internal control over financial reporting Basis for Opinion These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB. We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion. Critical Audit Matter The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates. Accrued Research and Development and Prepaid Expenses and Other Current Assets – Accrued and Prepaid Research and Development Expenses related to Contract Research Organizations (CROs) — Refer to Notes 2 and 5 to the financial statements Critical Audit Matter Description The Company records accrued expenses for costs of research and development activities which include the conduct of clinical studies by third-party CRO service providers, based upon the estimated amount of services provided but not yet invoiced. Any payments made in advance of services provided are recorded as prepaid assets, which are expensed as the contracted services are performed. The Company estimates the amount of work completed through review of detailed budgets and timelines included in its contracts and agreements, and updates these estimates with information obtained from third-party service providers and internal personnel on a quarterly basis. Given the significant judgments made by management in estimating the progress or stage of completion of the services, auditing the Company’s accrued and prepaid research and development expenses related to CROs was especially challenging. Specifically, because the amount of accrued and prepaid research and development expenses is dependent on management’s receipt of timely and accurate reporting from third-party service providers, management’s estimates of work completed as of the balance sheet date, and management’s estimates of the period over which this work will be performed, 87 auditing accrued and prepaid research and development expenses related to CROs required a high degree of auditor judgment and an increased extent of effort. How the Critical Audit Matter Was Addressed in the Audit Our audit procedures related to the Company’s accrued and prepaid research and development expenses included the following, among others: • We tested the effectiveness of controls over the estimation of accrued and prepaid research and development expenses related to CROs. • For a sample of agreements and contracts, we read the related statement of work, purchase order, and inspected information the Company received from its third-party service providers. We tested the accuracy and completeness of the underlying information used in the estimates and evaluated the significant assumptions that are used by management to estimate the recorded amounts by performing the following procedures: ◦ Performed corroborating inquiries with the Company’s research and development personnel that oversee the contract research organization’s studies to obtain information regarding the nature and extent of progress of the clinical studies. ◦ Obtained written confirmations directly from the Company’s third-party service providers regarding the accuracy and completeness of contracted amounts and percentage of completion. ◦ Evaluated management’s judgments using the evidence obtained. ◦ For a sample of agreements and contracts, we obtained the corresponding invoices and evidence of payment to test the Company’s disbursements made to third-party service providers as of December 31, 2023. • We compared invoices received by the Company subsequent to December 31, 2023 to the accrued research and development expenses related to CROs recognized by the Company as of that date. /s/ Deloitte & Touche LLP San Francisco, California February 27, 2024 We have served as the Company's auditor since 2018. 88 Pliant Therapeutics, Inc. Balance Sheets (In thousands, except number of shares and per share amounts) December 31, 2023 December 31, 2022 Assets Current assets Cash and cash equivalents $ 63,234 $ 33,685 Short-term investments 431,011 297,502 Accounts receivable — 1,983 Tax credit receivable — 83 Prepaid expenses and other current assets (Note 5) 11,257 7,058 Total current assets 505,502 340,311 Property and equipment, net 3,567 4,486 Operating lease right-of-use assets 1,211 5,422 Restricted cash 1,482 — Other non-current assets 392 394 Total assets $ 512,154 $ 350,613 Liabilities and stockholders’ equity Current liabilities Accounts payable $ 4,531 $ 1,580 Accrued research and development 12,456 11,218 Accrued liabilities (Note 6) 10,219 8,658 Lease liabilities, current 1,318 2,457 Total current liabilities 28,524 23,913 Lease liabilities, non-current — 3,429 Long-term debt (Note 7) 10,054 9,929 Total liabilities 38,578 37,271 Commitments and Contingencies (Note 13) Stockholders’ equity Preferred stock, $ 0.0001 par value 10,000,000 shares authorized at December 31, 2023 and 2022, none issued or outstanding at December 31, 2023 and 2022 — — Common stock, $ 0.0001 par value; 300,000,000 shares authorized at December 31, 2023 and 2022; and 59,921,002 and 48,941,254 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively; 6 5 Additional paid-in capital 972,973 653,707 Accumulated deficit ( 499,748 ) ( 338,412 ) Accumulated other comprehensive gain (loss) 345 ( 1,958 ) Total stockholders’ equity 473,576 313,342 Total liabilities and stockholders’ equity $ 512,154 $ 350,613 The accompanying notes are an integral part of these financial statements. 89 Pliant Therapeutics, Inc. Statements of Operations and Comprehensive Gain (Loss) (In thousands, except number of shares and per share amounts) Year Ended December 31, 2023 2022 2021 Revenue $ 1,580 $ 9,685 $ 7,572 Operating expenses: Research and development ( 127,797 ) ( 96,936 ) ( 77,549 ) General and administrative ( 57,928 ) ( 39,949 ) ( 27,558 ) Total operating expenses ( 185,725 ) ( 136,885 ) ( 105,107 ) Loss from operations ( 184,145 ) ( 127,200 ) ( 97,535 ) Interest and other income (expense), net 24,076 4,670 272 Interest expense ( 1,267 ) ( 791 ) — Net loss $ ( 161,336 ) $ ( 123,321 ) $ ( 97,263 ) Net loss per share - basic and diluted $ ( 2.75 ) $ ( 2.94 ) $ ( 2.71 ) Weighted average shares used in computing net loss per share - basic and diluted 58,719,083 42,015,908 35,846,421 Comprehensive loss: Net loss $ ( 161,336 ) $ ( 123,321 ) $ ( 97,263 ) Net unrealized gain (loss) on short-term investments 2,303 ( 1,757 ) ( 169 ) Total other comprehensive gain (loss) 2,303 ( 1,757 ) ( 169 ) Comprehensive loss $ ( 159,033 ) $ ( 125,078 ) $ ( 97,432 ) The accompanying notes are an integral part of these financial statements. 90 Pliant Therapeutics, Inc. Statements of Stockholders’ Equity (In thousands, except number of shares and per share amounts) Additional Paid-In Capital Accumulated Other Comprehensive (Loss) Gain Accumulated Deficit Total Stockholders' Equity Common Stock Shares Amount Balance at December 31, 2020 35,552,795 $ 3 $ 400,918 $ ( 32 ) $ ( 117,828 ) $ 283,061 Issuance of common stock under benefit plans 427,342 — 2,984 — — 2,984 Vesting of restricted stock awards 103,164 — 9 — — 9 Stock-based compensation expense — — 10,437 — — 10,437 Net unrealized loss on short-term investments — — — ( 169 ) — ( 169 ) Net loss — — — — ( 97,263 ) ( 97,263 ) Balance at December 31, 2021 36,083,301 $ 3 $ 414,348 $ ( 201 ) $ ( 215,091 ) $ 199,059 Common stock issued in a public offering, net of offering expenses 12,432,432 2 215,399 — — 215,401 Issuance of common stock under benefit plans 403,680 — 1,360 — — 1,360 Vesting of restricted stock awards 21,841 — 2 — — 2 Stock-based compensation expense — — 22,598 — — 22,598 Net unrealized loss on short-term investments — — — ( 1,757 ) — ( 1,757 ) Net loss — — — — ( 123,321 ) ( 123,321 ) Balance at December 31, 2022 48,941,254 $ 5 $ 653,707 $ ( 1,958 ) $ ( 338,412 ) $ 313,342 Common stock issued in a public offering, net of offering expenses 9,583,334 1 269,781 — — 269,782 Issuance of common stock under benefit plans 1,396,414 — 5,002 — — 5,002 Stock-based compensation expense — — 44,483 — — 44,483 Net unrealized gain on short-term investments — — — 2,303 — 2,303 Net loss — — — — ( 161,336 ) $ ( 161,336 ) Balance at December 31, 2023 59,921,002 $ 6 $ 972,973 $ 345 $ ( 499,748 ) $ 473,576 The accompanying notes are an integral part of these financial statements. 91 Pliant Therapeutics, Inc. Statements of Cash Flows (In thousands) Year Ended December 31, 2023 2022 2021 Cash flows from operating activities Net loss $ ( 161,336 ) $ ( 123,321 ) $ ( 97,263 ) Adjustments to reconcile net loss to net cash used in operating activities: Depreciation expense 1,841 1,823 1,535 Stock-based compensation expense 44,483 22,598 10,437 Non-cash operating lease expense 2,390 1,858 1,669 (Accretion) amortization on short-term investments and debt ( 4,990 ) ( 1,806 ) 1,262 Changes in operating assets and liabilities: Accounts receivable 1,983 15 7,281 Prepaid expenses and other current assets ( 3,735 ) ( 294 ) ( 2,266 ) Other non-current assets — 201 70 Accounts payable 2,969 ( 1,351 ) 891 Accrued liabilities 2,781 7,904 2,695 Operating lease liabilities ( 2,747 ) ( 2,258 ) ( 1,754 ) Net cash used in operating activities ( 116,361 ) ( 94,631 ) ( 75,443 ) Cash flows from investing activities Purchase of short-term investments ( 583,069 ) ( 325,716 ) ( 219,887 ) Maturity of short-term investments 456,978 177,272 295,539 Purchase of property and equipment ( 921 ) ( 1,760 ) ( 1,953 ) Net cash (used in) provided by investing activities ( 127,012 ) ( 150,204 ) 73,699 Cash flows from financing activities Proceeds from sale of common stock in a public offering 270,251 216,201 — Proceeds from issuances of common stock under benefit plans 5,001 1,360 2,984 Payment of offering costs ( 847 ) ( 557 ) ( 457 ) Payment of debt issuance costs — ( 150 ) — Proceeds from term loan — 10,000 — Net cash provided by financing activities 274,405 226,854 2,527 Net increase (decrease) in cash and cash equivalents 31,032 ( 17,981 ) 783 Cash and cash equivalents at beginning of period 33,684 51,665 50,882 Cash, cash equivalents and restricted cash at end of period $ 64,716 $ 33,684 $ 51,665 Supplemental disclosures of cash flow information: Cash paid for interest $ 1,149 $ 615 $ — Reconciliation of cash, cash equivalents, and restricted cash reported in the balance sheets Cash and cash equivalents $ 63,234 $ 33,684 $ 51,665 Restricted cash 1,482 — — Total cash, cash equivalents, and restricted cash shown in the statements of cash flows $ 64,716 $ 33,684 $ 51,665 Supplemental disclosures of noncash investing and financing activities: Net unrealized gain(loss) on short-term investments $ 2,303 $ ( 1,757 ) $ ( 169 ) Purchase of property and equipment in accounts payable $ — $ — $ 57 Reclassification of restricted stock awards from liabilities to common stock upon vesting $ — $ 2 $ 9 Supplemental disclosures of cash flow information related to leases: Cash paid for operating lease liabilities in operating cash flows $ 3,846 $ 2,657 $ 2,400 Right-of-use assets obtained in exchange for new operating lease liabilities $ — $ 950 $ — Decrease in right-of -use assets and liabilities from lease modifications $ 1,821 $ — $ — The accompanying notes are an integral part of these financial statements. 92 Pliant Therapeutics, Inc. Notes to Financial Statements 1. Organization and Description of Business Pliant Therapeutics, Inc. (the “Company” or "Pliant" or “we” or “our” or “us”) is a late stage 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 Offerings 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. In 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 $ 269.8 million, net of underwriting discounts, commissions and offering expenses payable by us. 2. Summary of Significant Accounting Policies 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 93 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 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”) 94 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, 2023, 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. The single operating segment constitutes all of the Company activity, the chief operating decision maker regularly reviews the entity-wide operating results and 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. Restricted Cash Our restricted cash balance of $ 1.4 million as of December 31, 2023 represented cash required to be held as collateral by a financial institution to guarantee lease payments due to our landlord at Oyster Point Blvd, South San Francisco, California (the "Oyster Point Lease"). 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, 2023 and 2022, 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 gain (loss) in the statements of operations and comprehensive loss. See Note 3 for further details. 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. The Company has not recorded any credit losses during the three years ended December 31, 2023, 2022 and 2021. 95 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 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, 2023, 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 96 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") and performance-based restricted stock units ("PSUs"), issued under the Company's 2020 Stock Option and Incentive Plan (the “2020 Plan”), 2022 Inducement Plan ("Inducement Plan") and shares 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 97 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 gain (loss) represents unrealized losses on short-term investments. Interest and other income(expense) Interest and other income (expense) 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, 2023, 2022 and 2021. Recently Adopted Accounting Pronouncements In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280), or Topic 280, which improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. We adopted the provisions of Topic 280 and the adoption did not have a material impact to our financial statements. Recently Announced Accounting Pronouncements I n October 2023, the Financial Accounting Standards Board ("FASB") issued ASU 2023-06 "Disclosure Improvements - Codification Amendments in Response to the SEC's Disclosure Update and Simplification Initiative", which amends the disclosure or presentation requirements related to various subtopics in the FASB Accounting Standard Codification (the "Codification"). This ASU will become effective on the date the SEC removes the applicable disclosure from Regulation S-X or Regulation S-K, with early adoption prohibited. If by June 30, 2027, the SEC has not removed the applicable requirement from Regulation S-X or Regulation S-K, the pending content of the related amendment will be removed from the Codification and will not be become effective for any entity. The Company expects the new guidance will have an immaterial impact on its financial statements, and intends to adopt the guidance when it becomes effective. In December 2023, the FASB issued ASU 2023-09 "Income Taxes (Topic 740): Improvements to Income Tax Disclosures", which expands disclosures in an entity’s income tax rate reconciliation table and regarding cash taxes paid both in the U.S. and foreign jurisdictions. The guidance is effective for the Company beginning in the fourth quarter of fiscal year 2026. The Company expects the new guidance will have an immaterial impact on its financial statements, and intends to adopt the guidance prospectively when it becomes effective in the fourth quarter of fiscal year 2026. 3. 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 gain or loss recognized in other comprehensive gain (loss). 98 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. 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. Accounting guidance 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 fair value of 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. 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, 2023 and 2022. The following tables show the Company’s cash and cash equivalents and short-term investments by significant investment category as of December 31, 2023 and 2022 (in thousands): As of December 31, 2023 As of December 31, 2022 Adjusted Cost Unrealized Gains Unrealized Losses Market Value Adjusted Cost Unrealized Gains Unrealized Losses Market Value Money Market Funds Level 1 $ 57,241 $ — $ — $ 57,241 $ 28,312 $ — $ — $ 28,312 U.S. Treasury securities Level 2 27,250 46 ( 8 ) 27,288 4,446 — ( 5 ) 4,441 U.S. Government Agency Securities Level 2 133,655 563 ( 132 ) 134,086 28,746 — ( 111 ) 28,635 Corporate debt securities Level 2 269,761 213 ( 337 ) 269,637 266,267 45 ( 1,887 ) 264,425 Total financial assets $ 487,907 $ 822 $ ( 477 ) $ 488,252 $ 327,771 $ 45 $ ( 2,003 ) $ 325,813 As of December 31, 2023 As of December 31, 2022 Classified as: Adjusted Cost Unrealized Gains Unrealized Losses Market Value Adjusted Cost Unrealized Gains Unrealized Losses Market Value Cash equivalents $ 57,241 $ — $ — $ 57,241 $ 28,312 $ — $ — $ 28,312 Short-term investments 430,666 822 ( 477 ) 431,011 299,459 45 ( 2,003 ) 297,501 Total $ 487,907 $ 822 $ ( 477 ) $ 488,252 $ 327,771 $ 45 $ ( 2,003 ) $ 325,813 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. 99 The following summarizes the remaining contractual maturities of the Company’s short-term investments as of December 31, 2023: Adjusted Cost Market Value Mature in 1 year or less $ 316,700 $ 316,366 Mature in 1 to 2 years 113,966 114,645 Total $ 430,666 $ 431,011 There were no liabilities measured at fair value on a recurring basis as of December 31, 2023 and 2022. There have been no transfers between fair value measurement levels during the years ended December 31, 2023 and 2022. In addition, there were no assets or liabilities measured at fair value on a non-recurring basis as of December 31, 2023 and 2022. 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(expense),net in its statement of operations and comprehensive gain (loss). 4. Property and Equipment, net Property and equipment, net consisted of the following (in thousands): December 31, 2023 2022 Laboratory equipment $ 10,410 $ 9,581 Leasehold improvements 1,663 1,650 Construction-in-progress 52 66 Computer equipment and software 124 30 Total property and equipment 12,249 11,327 Less: Accumulated depreciation ( 8,682 ) ( 6,841 ) Total property and equipment, net $ 3,567 $ 4,486 Depreciation expense during the years ended December 31, 2023 and 2022 was $ 1.8 million, and for 2021 depreciation expense was $ 1.5 million. 5. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2023 2022 Prepaid research and development $ 3,403 $ 3,421 Prepaid insurance 1,131 1,427 Prepaid licenses 2,454 959 Interest receivable 2,997 1,078 Other 1,272 173 Total prepaid expenses and other current assets $ 11,257 $ 7,058 6. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 31, 2023 2022 Accrued compensation and benefits $ 9,042 $ 7,200 Other accrued liabilities 1,177 1,458 Total accrued liabilities $ 10,219 $ 8,658 Accrued compensation and benefits consist primarily of accrued bonuses and accrued vacation. 100 7. 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 and we decided not to draw upon the additional $ 65.0 million that became available to us over the course of 2023 as certain conditions related to the development of bexotegrast and one of our preclinical product candidates were satisfied. As of December 31, 2023, the time period to draw upon the additional $ 65.0 million had lapsed. 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 with monthly interest and principal payments thereafter until the maturity date of May 1, 2027. The estimated fair value of the term loan as of December 31, 2023 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 years ended December 31, 2023 and 2022 was $ 1.3 million and $ 0.8 million, respectively. Future maturities of debt as of December 31, 2023 are as follows (in thousands): As of December 31, 2023 2026 $ 5,455 2027 4,545 Thereafter — Total 10,000 Less: unamortized debt issuance costs ( 106 ) Accretion of final payment 160 Total $ 10,054 8. Novartis Collaboration and License Agreement (the "Novartis Agreement") In 2019, we entered into the Novartis Agreement with Novartis Institutes for BioMedical Research, Inc. (“Novartis”) for the development and commercialization of our preclinical product candidate, PLN-1474, and up to three additional integrin research targets. We assessed the Novartis Agreement in accordance with ASC 606 and determined that Novartis was 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. On February 17, 2023, Novartis exercised their right to terminate the Novartis Agreement as part of their new strategy focusing on a limited number of therapeutic areas. The termination took effect on April 18, 2023, and effective upon the termination, all rights and licenses granted to Novartis under the Novartis Agreement, including PLN-1474, the related investigational new drug (“IND”), and the validated research target, reverted back to us. The payment obligations of Novartis with respect to future milestones, royalties and research and development funding were also terminated. Revenues associated with the Novartis Agreement for the years ended December 31, 2023, 2022 and 2021, were $ 1.6 million, $ 9.7 million and $ 7.6 million, respectively, which consisted of revenue generated from research and development services and a $ 4.0 million contingent payment received in 2022 associated with the integrin research target program. As of December 31, 2023 and 2022, there was a receivable of nil and $ 2.0 million, respectively, related to the Novartis Agreement. There were no contract assets or contract liabilities as of December 31, 2023 and 2022. 9. Preferred Stock Under the Company’s Amended and Restated Certificate of Incorporation, the Company is authorized to issue two classes of shares: preferred stock and common stock. The preferred stock may be issued in series, and the Company’s board of directors is authorized to determine the rights, preferences, and terms of each series. These rights, preferences and terms could include dividend rights, conversion rights, voting rights, terms of redemptions, liquidation preferences and 101 sinking fund terms. As of December 31, 2023 and 2022, the Company was authorized to issue 10,000,000 shares of preferred stock and there was no outstanding preferred stock as of December 31, 2023 and 2022. 10. Common Stock As of December 31, 2023 and 2022, 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, 2023 2022 Outstanding stock option awards 6,953,487 5,569,567 Vesting of RSUs 874,748 507,925 Vesting of PSUs* 328,752 531,796 Shares of common stock available for future grants under the 2020 Stock Option and Incentive Plan 2,882,239 2,937,769 Shares of common stock available for future issuance under the 2020 ESPP 805,756 888,184 Shares of common stock available for future issuance under the 2022 Inducement Plan 700,000 1,000,000 Total shares reserved for future issuance 12,544,982 11,435,241 *PSUs granted and outstanding based on target level of achievement of 100 %. 11. 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 compensation committee of the Board of Directors. 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, 2023, the 2020 Plan had 2,882,239 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 nonqualified stock options or other awards including stock appreciation rights and restricted stock awards. As of December 31, 2023, 700,000 shares of common stock were available for issuance. 102 Options under the 2020 Plan and Inducement 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 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. Incentive Stock Options and Nonqualified Stock Options Stock options issued under either the 2015 Plan, the 2020 Plan or the Inducement 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, 2023 2022 2021 Min Max Min Max Min Max Expected volatility 80.97 % 83.28 % 73.78 % 80.64 % 74.83 % 76.31 % Risk-free interest rate 3.42 % 4.68 % 1.64 % 4.16 % 0.61 % 1.39 % Expected dividend — — — — — — Expected term (in years) 5.31 6.08 5.33 6.08 5.44 6.08 Underlying common stock fair value $ 15.25 $ 34.65 $ 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, 2022 5,569,567 $ 13.34 7.96 $ 43,696 Granted 2,158,764 $ 27.22 Exercised ( 534,706 ) $ 6.91 Forfeited ( 240,138 ) $ 18.81 Outstanding as of December 31, 2023 6,953,487 $ 17.95 7.70 $ 32,646 Exercisable as of December 31, 2023 3,515,801 $ 15.03 6.74 $ 23,184 Vested and expected to vest as of December 31, 2023 6,953,487 $ 17.95 7.70 $ 32,646 As of December 31, 2023, there was $ 46.4 million of unrecognized compensation costs that is expected to be recognized over the weighted-average periods of 2.5 years related to stock options. The total intrinsic value of stock options exercised was $ 11.4 million, $ 2.0 million and $ 6.9 million for December 31, 2023, 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 at the respective balance sheet dates. The weighted-average grant date fair value of options granted during the years ended December 31, 2023, 2022 and 2021 was $ 27.22 , $ 7.82 and $ 16.94 per share, respectively. 103 Restricted Stock Units The service-based condition for restricted stock units ("RSUs") is generally satisfied over two or three years . The following table sets forth the outstanding RSUs and related activity for the year ended December 31, 2023: Restricted Stock Units Weighted Average Grant Date Fair Value Unvested and outstanding as of December 31, 2022 507,925 $ 17.43 Granted 683,703 $ 34.36 Released ( 247,488 ) $ 17.43 Forfeited ( 69,392 ) $ 27.69 Unvested and outstanding as of December 31, 2023 874,748 $ 29.85 As of December 31, 2023, the Company had $ 17.4 million of unrecognized stock-based compensation expense related to outstanding RSUs expected to be recognized over a weighted-average period of 1.66 years. Performance-Based Restricted Stock Units In July 2022 the Company granted performance-based restricted stock units ("PSUs") that 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 years ended December 31, 2023 and 2022: Performance Stock Units Weighed 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 Forfeited ( 25,782 ) $ 29.15 Unvested balance as of December 31, 2023 328,750 $ 29.15 As of December 31, 2022 177,266 PSUs, with a weighted average grant date fair value of $ 17.57 , associated with clinical development milestones met their vesting conditions. In March and July 2023 the second and the third clinical development vesting conditions were achieved and the remaining 531,792 PSUs relating to clinical development vesting 104 conditions vested, representing total stock based compensation of $ 7.3 million. There are no remaining PSUs with clinical development performance conditions outstanding as of December 31, 2023. As of December 31, 2023, the Company had $ 2.6 million of unrecognized stock-based compensation expense related to unvested PSUs associated with market based vesting conditions are expected to be recognized over a remaining weighted-average period of 0.54 years. 2020 Employee Stock Purchase Plan In June 2020, the Company adopted the 2020 Employee Stock Purchase Plan (the "2020 ESPP") and reserved 700,000 shares of common stock for future issuance under the plan. The 2020 ESPP is subject to automatic increases on January 1 of each calendar year, beginning January 1, 2021, by the lesser of (i) 1 % of the outstanding shares on the immediately preceding December 31, (ii) 700,000 shares or (iii) such lesser amount as determined by, the compensation committee of the Board of Directors. Under the 2020 ESPP, eligible employees may purchase shares of our common stock through payroll deductions that cannot exceed 15 % of the 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 or end of the offering period subject to tax limitations on the total value of the purchase. The 2020 ESPP is considered a compensatory plan, and the Company recorded $ 0.6 million, $ 0.4 million and $ 0.5 million in stock-based compensation expense for years ended December 31, 2023, 2022 and 2021, respectively. During the years ended December 31, 2023, 2022 and 2021, 82,428 shares, 85,969 shares and 86,902 shares, respectively, 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, 2023 2022 2021 Risk-free interest rate 5.20 % - 5.47 % 0.60 % - 3.34 % 0.06 % - 0.07 % Expected term of options (in years) 0.50 0.50 0.50 Expected stock price volatility 54.78 % - 69.15 % 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, 2023, 2022 and 2021 (in thousands): Year Ended December 31, 2023 2022 2021 Restricted stock awards $ — $ 36 $ 182 Stock options and ESPP 21,313 13,280 10,255 Restricted stock units 11,149 1,892 — Performance-based restricted stock units 12,021 7,390 — Total stock-based compensation expense $ 44,483 $ 22,598 $ 10,437 Research and development expenses $ 17,973 $ 8,730 $ 3,928 General and administrative expenses $ 26,510 $ 13,867 $ 6,509 12. Income Taxes The Company had a pre-tax U.S. book loss of $ 161.3 million, $ 123.3 million, and $ 97.3 million, for the years ended December 31, 2023, 2022 and 2021, respectively. During the years ended December 31, 2023, 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. 105 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, 2023 2022 2021 Income tax computed at federal statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit 6.7 % 7.3 % 7.7 % General business credit—federal 5.3 % 3.6 % 5.3 % Stock-based compensation 0.9 % ( 1.0 ) % ( 0.7 ) % Other permanent differences 0.1 % ( 0.4 ) % ( 0.1 ) % Section 162(m) ( 3.8 ) % — % — % Change in valuation allowance ( 30.2 ) % ( 30.5 ) % ( 33.2 ) % Effective income tax rate — % — % — % Net deferred tax assets and liabilities consisted of the following (in thousands): December 31, 2023 2022 Deferred tax assets: Net operating losses $ 78,452 $ 65,689 Research and development credits 29,559 19,688 Accrued expenses 2,211 387 Other 1,350 1,706 Capitalized research and development 34,769 13,900 Lease liability 369 1,638 Stock based compensation 8,291 5,073 Total deferred tax assets 155,001 108,081 Deferred tax liabilities: Fixed asset basis ( 123 ) ( 258 ) Prepaid expenses ( 598 ) ( 630 ) Right of use asset ( 339 ) ( 1,509 ) Total deferred tax liabilities ( 1,060 ) ( 2,397 ) Valuation allowance 153,941 105,684 Net deferred taxes $ — $ — Net operating losses and tax credit carryforwards were as follows (in thousands): December 31, 2023 Expiration Year Net operating losses, federal (starting from January 1, 2018) $ 212,005 Does not expire Net operating losses, federal (before January 1, 2018) $ 29,486 2035-2037 Net operating losses, state $ 397,559 2035-2043 Tax credits, federal $ 31,512 2036-2043 Tax credits, state $ 7,145 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, 2023 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, 2023 and 2022, 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 106 future. Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2023 and 2022 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, 2023 2022 Valuation allowance at the beginning of the year $ 105,684 $ 67,684 Increases recorded to income tax provision 48,257 38,000 Valuation allowance at the end of the year $ 153,941 $ 105,684 The Company’s U.S. federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2018 through December 31, 2023. 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, 2023 and 2022, 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, 2023 2022 January 1 $ 5,196 $ 3,505 Additions based on tax positions related to current year 2,475 1,547 Additions for tax positions of prior year 303 144 December 31 $ 7,974 $ 5,196 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. 13. 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. 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. 107 14. Leases New Lease On September 28, 2023, the Company entered into a lease agreement for a premise consisting of approximately 100,904 square feet located at Oyster Point Blvd, South San Francisco, California (the "Oyster Point Lease"), which the Company intends to use as laboratory and office space. The lease term of approximately seven years will start upon the Landlord’s substantial completion of tenant improvements, and may be extended for a period of eight years at then prevailing market rates for a comparable property. Future lease payments are approximately $ 43.7 million and are expected to start in the third quarter of 2024. Additionally, the Company is required to provide a letter of credit to the Landlord in the amount of $ 1.4 million in connection with the Oyster Point Lease. The Company has not recognized a right-of-use asset ("ROU") or aggregate lease liability as of December 31, 2023 for this lease as the Company did not control the underlying assets at any time during the year ended December 31, 2023. Existing leases In conjunction with the Oyster Point Lease, we modified the lease term of our existing lease to end upon the start date of the Oyster Point Lease. As a result of this modification, we reduced our lease liability and our right-of-use asset by $ 1.8 million as of December 31, 2023. Additionally, we paid a refundable security deposit of approximately $ 0.4 million at inception of the lease term which has been reclassified from other non-current assets to other current assets in the balance sheet of December 31, 2023. Operating lease ROU assets and liabilities on our balance sheets represent the present value of our remaining lease payments over the remaining lease terms. We use our incremental borrowing rate to calculate the present value of our lease payments, as the implicit rates in our leases are not readily determinable. Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, the Company used its incremental borrowing rate based on the information available at the date of adoption of Topic 842 or the date of lease modification. The undiscounted future non-cancellable lease payments of the Company's operating lease liability as of December 31, 2023 were as follows (in thousands): Year ending December 31: Operating Leases 2024 $ 1,382 Total undiscounted lease payments 1,382 Less: Present value discount ( 64 ) Total current operating lease liabilities 1,318 Total non-current operating lease liabilities $ — The weighted-average remaining lease terms and discount rates related to the Company's operating leases were as follows: As of December 31, 2023 2022 Weighted-average remaining lease term (in years) 0.6 2.3 Weighted-average discount rate 13.60 % 8.2 % Variable lease costs comprise 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, 2023, 2022 and 2021. Lease expenses for the years ended December 31, 2023, 2022 and 2021 are as follows (in thousands) As of December 31, 2023 2022 2021 Operating lease costs $ 2,771 $ 2,501 $ 2,300 Other variable costs 766 721 949 Total expense $ 3,537 $ 3,222 $ 3,249 108 15. Related Party Transactions In 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 ve st have all vested . The stock-based compensation expense related to these options was immaterial during the years ended December 31, 2022, and 2021. There were no related party transactions during the year ended December 31, 2023. 16. Defined Contribution Plan The 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 $ 1.0 million, $ 0.8 million and $ 0.6 million during the years ended December 31, 2023, 2022 and 2021, respectively. 17. 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, 2023 2022 2021 Options to purchase common stock 6,953,487 5,569,567 3,620,180 Restricted stock units 874,748 507,925 — Performance-based restricted stock units* 328,750 354,532 — Unvested restricted shares — — 21,841 Total 8,156,985 6,432,024 3,642,021 *PSUs outstanding based on target level of achievement of 100 %. Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure. None.