PLRX US Equity☆

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion and analysis is intended to provide material information around events and uncertainties known to management relevant to an assessment of the financial condition and results of operations of the Company and should therefore be read in conjunction with our audited Financial Statements and the accompanying Notes to Financial Statements and other disclosures included in this Annual Report on Form 10-K (including the disclosures under Part I, Item 1A. Risk Factors) where other material events and uncertainties not otherwise discussed below are disclosed. Certain amounts and percentages herein may not sum or recalculate due to rounding. The following discussion and analysis does not address certain items regarding the year ended December 31, 2021. Discussion and analysis of 2021 and year-to-year comparisons between 2022 and 2021 that are not included in this Report can be found in Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations of our 2022 Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC on March 9, 2023”).

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Report, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate we have conducted exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

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Overview

We are a late stage biopharmaceutical company focused on discovering and developing novel therapies for the treatment of fibrosis and related diseases. Our initial focus is on treating fibrosis by inhibiting integrin-mediated activation of TGF-β. We have applied our deep understanding of fibrosis biology, along with our medicinal chemistry and translational medicine expertise to develop a set of proprietary tools designed to discover and de-risk product candidates quickly and efficiently. Our wholly-owned lead product candidate, bexotegrast (PLN-74809), is an oral, small molecule, dual selective inhibitor of αvß6 and αvß1 integrins that we are developing for the treatment of idiopathic pulmonary fibrosis, or IPF, and primary sclerosing cholangitis, or PSC. We are currently conducting a Phase 2b trial in IPF and a Phase 2a trial in PSC. We announced positive data from our Phase 2a INTEGRIS-IPF trial in May 2023. We are currently conducting BEACON-IPF, a 52-week, randomized, double-blind, placebo-controlled Phase 2b trial in patients with IPF. We announced positive interim data from our Phase 2a INTEGRIS-PSC trial in September 2023 and February 2024. We expect to release final data from the INTEGRIS-PSC trial in mid-2024.

In January 2023, we received FDA clearance of investigational new drug application, or IND, for our third clinical program to date, PLN-101095, a dual inhibitor of integrins αvß8 and αvß1 for the treatment of solid tumors that are resistant to immune checkpoint inhibitors. We are currently dosing the third of five dose cohorts in a Phase 1 open label dose-escalation trial of PLN-101095 as monotherapy and in combination with pembrolizumab in patients with solid tumors that are resistant to immune checkpoint inhibitors. We expect to release preliminary data from the trial in late 2024.

Our fourth program to date, PLN-101325, in development for treatment of muscular dystrophies, including Duchenne muscular dystrophy. PLN-101325 is a monoclonal antibody designed to act as an allosteric agonist of integrin α7ß1. We expect to file with regulators for first-in-human studies in the first quarter of 2024.

We have developed PLN-1474, a Phase 2-ready oral, small molecule selective inhibitor of αvß1 for the treatment of advanced liver fibrosis associated with nonalcoholic steatohepatitis, or NASH. PLN-1474 was licensed to Novartis in 2019, and as part of a broad strategic realignment, Novartis has discontinued clinical development in NASH and, as a result, discontinued development of PLN-1474. In February 2023, Novartis returned global rights to PLN-1474 to Pliant.

Recent Highlights

Bexotegrast Highlights

•Positive safety and efficacy data from 320 mg dose cohort of INTEGRIS-PSC Phase 2a trial in patients with primary sclerosing cholangitis (PSC). At a once-daily dose of 320 mg, bexotegrast was well tolerated over 12 weeks of treatment with no drug-related severe or serious adverse events. At the 320 mg dose, bexotegrast reduced both Enhanced Liver Fibrosis (ELF) scores and PRO-C3 levels and showed improvements in hepatocyte function and bile flow by contrast MRI imaging relative to placebo at Week 12. Twenty-four-week data from the 320 mg dose group is expected in mid-2024.

•Enrollment continues in BEACON-IPF, a Phase 2b trial of bexotegrast in patients with idiopathic pulmonary fibrosis (IPF). BEACON-IPF is a 52-week, multinational, randomized, dose-ranging, double-blind, placebo-controlled trial evaluating bexotegrast at once-daily doses of 160 mg or 320 mg. BEACON-IPF is expected to enroll approximately 270 patients with IPF.

Pipeline Programs

•Phase 1 trial of PLN-101095 in solid tumors is enrolling. This is a Phase 1 open label trial of PLN-101095, an oral, small molecule, dual selective inhibitor of αvβ8 and αvβ1 integrins designed to block TGF-β activation in the tumor microenvironment. The trial is currently dosing the third of five planned dose cohorts in a Phase 1 open label dose-escalation trial of PLN-101095 as monotherapy and in combination with pembrolizumab in patients with solid tumors that are resistant to immune checkpoint inhibitors. Preliminary data is expected in late 2024.

•Muscular dystrophy program on track for regulatory filing in the first quarter of 2024. PLN-101325 is a monoclonal antibody designed to act as an allosteric agonist of integrin α7β1. Filing for first-in-human clinical studies in Duchenne muscular dystrophy (DMD) is expected in the first quarter of 2024.

Since inception, we have had significant operating losses. Our net loss was $161.3 million, $123.3 million and $97.3 million for the years ended December 31, 2023, 2022 and 2021, respectively. As of December 31, 2023, we had an accumulated deficit of $499.7 million and cash, cash equivalents, restricted cash and short-term investments of $495.7 million. We expect to continue to incur net losses for the foreseeable future, and we expect our research and development expenses, general and administrative expenses, and capital expenditures will increase in connection with our ongoing activities, as we:

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•perform research and development activities to identify and develop product candidates;

•advance product candidates into and through clinical development;

•require the manufacture of supplies to support research and development, preclinical studies and clinical trials;

•seek regulatory approvals for any product candidates that successfully complete clinical trials;

•expand our operational, financial and management systems and increase personnel to support our clinical development, manufacturing and commercialization efforts and our operations as a public company;

•maintain, expand and protect our intellectual property portfolio; and

•invest in or in-license other technologies or product candidates.

Financial Operations Overview

Revenue

We have not generated any revenue from product sales and do not expect to do so in the near future. Our revenue to date is derived from a Collaboration and License Agreement with Novartis, or the "Novartis Agreement," that was executed in 2019.

The Novartis Agreement was for the development and commercialization of PLN-1474 and up to three additional integrin research targets. Under the terms of the Novartis Agreement, we received an upfront license fee payment of $50.0 million for the worldwide, exclusive license to PLN-1474 and an additional $29.0 million upon the achievement of specified research and development milestones. As part of a broad strategic realignment, Novartis has discontinued clinical development in NASH and, as a result, discontinued development of PLN-1474. In February 2023, Novartis issued a termination notice for the collaboration and license agreement, and returned global rights to Pliant for PLN-1474.

Following termination of the Novartis Agreement, we were no longer eligible to receive additional milestone or royalty payments under the arrangement, however, we continued to earn research and development services revenues through the effective termination date of April 18, 2023.

Revenues for the years ended December 31, 2023, 2022 and 2021 were $1.6 million, $9.7 million and $7.6 million respectively.

Operating Expenses

Research and Development

Our research and development expenses consist of expenses incurred in connection with the development of our product candidates. Research and development expenses include:

•employee-related expenses, which include salaries, benefits and stock-based compensation for our research and development personnel;

•expenses incurred under agreements with third-party contract organizations for pre-clinical studies, clinical trials and consultants that conduct research and development activities on our behalf;

•costs associated with the manufacture of supplies to support research and development, preclinical studies and clinical trials;

•depreciation of laboratory equipment and costs of equipment and supplies;

•costs associated with technology and intellectual property licenses; and

•facilities and other allocated expenses, which include expenses for rent and other facility related costs and other supplies.

The following table summarizes our research and development expenses for the years ended December 31, 2023, 2022 and 2021 (in thousands):

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Year Ended December 31,

Technology and intellectual property licenses 78 85 33

We expense all research and development costs in the periods in which they are incurred. We do not allocate our internal costs by product candidates or by preclinical programs. Additionally, although external third-party costs are allocable between product candidates and programs, we do not perform this allocation.

We expect our research and development expenses to increase substantially for the foreseeable future as we continue to invest in research and development activities related to developing our product candidates and our preclinical programs and as they advance into later stages of development. The process of conducting the necessary clinical research to obtain regulatory approval is costly and time-consuming, and the successful development of our product candidates is highly uncertain. As a result, we are unable to determine the duration and completion costs of our research and development projects or when and to what extent we will generate revenue from the commercialization and sale of any of our product candidates.

General and Administrative

Our general and administrative expenses consist primarily of salaries, benefits and stock-based compensation for our general and administrative personnel, allocated facilities costs, insurance and other expenses for outside professional services, including legal, marketing, investor relations, human resource and accounting services. We expect general and administrative expenses to increase for the foreseeable future as does the size of our administrative function to support the growth of our business. In addition, if we obtain regulatory approval for any of our product candidates and do not enter into a third-party commercialization collaboration, we expect to incur significant expenses related to building a sales and marketing team to support product sales, marketing and distribution activities.

Interest and Other Income (Expense), net

Our interest and other income (expense), net consists of interest, accretion income and amortization expense on cash, cash equivalents and short-term investments, and realized gains and losses on short-term investments.

Interest Expense

Our interest expense is derived from a term loan executed under the Oxford Loan Agreement that we entered into in May 2022. 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.

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Results of Operations

Comparison of the Years Ended December 31, 2023 and 2022

(In thousands, except percentages) Year Ended December 31,

Operating expenses:

Revenue

Revenue decreased by $8.1 million due to decreased research and development services resulting from the termination of the Novartis Agreement.

Research and Development Expenses

The increase in research and development expenses of $30.9 million was primarily due to:

•$16.3 million increase in employee-related costs, including stock-based compensation, driven by an increase in our research and development workforce;

•$9.5 million decrease in outside and consulting services for preclinical studies which is largely attributable to decreased preclinical spend related to PLN-101095 as we initiated a phase 1 clinical trial during the second quarter of 2023, and an overall decrease in research and development activities as we prioritize bexotegrast clinical development;

•$23.2 million increase in clinical trial expenses largely due to continued development of bexotegrast, in particular our Phase 2b trial in patients with IPF, as well as the initiation of our phase 1 trial of PLN-101095 in solid tumors during the second quarter of 2023;

•$0.3 million decrease in depreciation of lab equipment and costs of equipment and supplies; and

•$1.1 million increase in facilities and other allocated expenses.

General and Administrative Expenses

The increase in general and administrative expenses by $18.0 million was primarily due to a $16.6 million increase in employee-related costs, including a $12.6 million increase in stock-based compensation, and increases in accounting and other professional services.

Interest and Other Income (Expense), Net

Interest and other income (expense), net increased $19.4 million due to higher average investment balances in 2023 compared to 2022 resulting from significant financing activities occurring mid-year 2022 and the public offering in January 2023, coupled with an increase in the yield on our short-term investment portfolio.

Interest Expense

Interest expense increased $0.5 million during the year as our Term Loan, issued in the second quarter of 2022, was outstanding the entire year of 2023 compared to eight months in the prior year.

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Liquidity and Capital Resources

Overview

As of December 31, 2023, we had cash, cash equivalents, restricted cash and short-term investments of $495.7 million. Our cash, cash equivalents and short-term investments consist of money market funds, U.S. Treasury securities, U.S. Government Agency securities and highly rated, investment-grade corporate debt securities.

In May 2022, as amended in October 2022, we entered into a Loan and Security Agreement (the “Oxford Loan Agreement”) with Oxford Finance LLC (or "Oxford"). Upon closing of the Oxford Loan Agreement, we drew $10.0 million and decided to forego drawing on 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. At December 31, 2023, $25.0 million remained available to us under the Oxford Loan Agreement.

In July 2022, we completed an underwritten 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 to the public 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, we completed an underwritten 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 to the public of $30.00 per share, resulting in aggregate proceeds of approximately $269.8 million, net of underwriting discounts, commissions and offering expenses.

During the third quarter of 2021, we entered into a Controlled Equity OfferingSM Sales Agreement (the “Sales Agreement”) with Cantor Fitzgerald & Co., as sales agent, pursuant to which we may issue and sell shares of common stock in an "at-the-market" offering. In March 2023, we filed a prospectus registering the offer and sale of up to $150.0 million of shares of common stock from time to time pursuant to the Sales Agreement. We have not issued any shares pursuant to any at-the-market offerings, including pursuant to the Sales Agreement, but may do so at a future date.

We believe that our existing capital resources, together with the funds available to us under the Oxford Loan Agreement, will be sufficient to fund our anticipated operating expenses and capital expenditure requirements for the next 12 months and for the longer-term period into the second half of 2026. We have based these estimates on assumptions that may prove to be wrong, and we could utilize our available capital resources sooner than we currently expect. Further, our operating plan may change, and we may need additional funds to meet operational needs and capital requirements for product development and commercialization sooner than planned.

Our operations have been financed primarily through the issuance and sale of common stock and convertible preferred stock and our collaboration with Novartis.

Funding Requirements

Our primary use of cash is to fund operating expenses, primarily research and development expenditures. Cash used to fund operating expenses is impacted by the timing of when we pay these expenses, as reflected in the change in our outstanding accounts payable, accrued expenses and prepaid expenses.

Our future funding requirements will depend on many factors, including the following:

•the initiation, progress, timing, costs and results of preclinical studies and clinical trials for our product candidates;

•the clinical development plans we establish for these product candidates;

•the timelines of our clinical trials and the overall costs to conduct and complete the clinical trials, which may be impacted by health epidemics and pandemics, such as COVID-19;

•the number and characteristics of product candidates that we develop;

•the outcome, timing and cost of meeting regulatory requirements established by the U.S. Food and Drug Administration, or FDA, and other comparable foreign regulatory authorities including but not limited to the European Medicines Agency (EMA), the U.. Medicines and Healthcare products Regulatory Agency (MHRA);

•whether we enter into any collaboration agreements and the terms of any such agreements;

•the cost of filing, prosecuting, defending and enforcing our patent claims and other intellectual property rights;

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•the cost of defending intellectual property disputes, including patent infringement actions brought by third parties against us or our product candidates;

•the effect of competing technological and market developments;

•the cost and timing of completion of commercial-scale outsourced manufacturing activities;

•the cost and timing of achieving favorable pricing and reimbursement agreements with the pricing authorities in each market of interest, including of securing a positive recommendation after undergoing a health technology assessment by health technology authorities;

•the cost of establishing sales, marketing and distribution capabilities for any product candidates for which we may receive regulatory approval in regions where we choose to commercialize our products on our own; and

•the cost of operating as a public company.

Further, our operating plan may change, and we may need additional funds to meet operational needs and capital requirements for clinical trials and other research and development expenditures. If we need to raise additional capital to fund our operations, funding may not be available to us on acceptable terms, or at all. If we are unable to obtain adequate financing when needed, we may have to delay, reduce the scope of or suspend one or more of our preclinical studies, clinical trials, research and development programs or commercialization efforts. We may seek to raise any necessary additional capital through a combination of public or private equity offerings, debt financings, collaborations and other licensing arrangements. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional capital through marketing and distribution arrangements or other collaborations, strategic alliances or licensing arrangements with third parties, we may have to relinquish certain valuable rights to our product candidates, technologies, future revenue streams or research programs or grant licenses on terms that may not be favorable to us.

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Cash Flows

The following summarizes our cash flows for the periods indicated (in thousands):

Year Ended December 31,

Cash Used in Operating Activities

The increase in cash used in operating activities of $21.7 million between the year ended December 31, 2023 and 2022 was primarily due to an increase in our operating expenses, notably for the continued development of bexotegrast and our other pipeline programs. Further, revenue related receipts decreased $6.2 million as we ceased to earn research and development services revenue following the termination of the Novartis Agreement.

Cash Used in Investing Activities

The decrease in cash used in investing activities of $23.2 million between the year ended December 31, 2023 and 2022 is primarily due to the timing of purchases of short-term investments compared to related maturities during each year.

Cash Provided by Financing Activities

The increase in cash provided by financing activities of $47.6 million between the year ended December 31, 2023 and 2022 is primarily due to net proceeds from the Company's January 2023 underwritten public offering.

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Off-Balance Sheet Arrangements

During the periods presented, we did not have, nor do we currently have, any off-balance sheet arrangements or holdings in any variable interest entities other than the operating lease commitments described in Note 14 to our financial statements appearing elsewhere in this Annual Report.

Material Cash Requirements

At December 31, 2023, we had various non-cancelable operating leases for office space and equipment, which expire between December 31, 2023 and March 31, 2031. Refer to Note 13 and Note 14 to our financial statements appearing elsewhere in this Annual Report for a discussion of material obligations and commitments.

We enter into contracts in the normal course of business with third-party contract organizations for clinical trials, non-clinical studies and testing, manufacturing and other services and products. These contracts generally provide for termination following a certain period after notice and therefore we believe that our cancellable obligations under these agreements are not material.

Critical Accounting Polices and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our financial statements, which have been prepared in accordance with United States generally accepted accounting principles. The preparation of these financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

While our significant accounting policies are described in more detail in Note 2 to our financial statements appearing elsewhere in this Annual Report, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our financial statements.

Revenue Recognition

As of December 31, 2023, all of our revenue to date has been generated from the Novartis Agreement. We recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. To determine the appropriate amount of revenue to be recognized for arrangements determined to be within the scope of Accounting Standards Codification Topic 606, Revenue from Contracts with Customers, ("Topic 606") we perform the following five steps: (i) identification of the contract(s) with the customer, (ii) identification of the promised goods or services in the contract and determination of whether the promised goods or services are performance obligations, (iii) measurement of the transaction price, (iv) allocation of the transaction price to the performance obligations, and (v) recognition of revenue when (or as) we satisfy each 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 our customer.

Identification of the Contracts with the Customers

We evaluate every contract to determine whether it in its entirety or in part represent a contract with a customer, or a collaboration agreement and, based on this determination, apply appropriate accounting guidance.

We account for a contract with a customer that is within the scope of Topic 606 when all of the following criteria are met: (i) the arrangement has been approved by the parties and the parties are committed to perform their respective obligations, (ii) each party’s rights regarding the goods or services to be transferred can be identified, (iii) the payment terms for the goods or services to be transferred can be identified, (iv) the arrangement has commercial substance and (v) collection of substantially all of the consideration to which we will be entitled in exchange for the goods or services that will be transferred to the customer is probable.

Identification of the Performance Obligations

The promised goods or services in our collaboration and option arrangements consist of license and research and development services. The arrangements also have options for additional items (i.e., license rights). Options are considered to be marketing offers and are to be accounted for as separate contracts when the customer elects such options, unless we determine the option provides a material right which would not be provided without entering into the contract. The determination as to whether such options are material rights requires significant management judgment, and management

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considers factors such as other similar arrangements, market data and the terms of the contractual arrangement to make such conclusion. Performance obligations are promised goods or services in a contract to transfer a distinct good or service to the customer. Promised goods or services are considered distinct when: (i) the customer can benefit from the good or service on its own or together with other readily available resources and (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, we consider factors such as the stage of development of the underlying intellectual property, the capabilities of our customer to develop the intellectual property on their own and whether the required expertise is readily available.

Determination of the Transaction Price

We estimate the transaction price based on the amount of consideration we expect to receive for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. At the inception of each arrangement that includes variable consideration, we evaluate the amount of the potential payments and the likelihood that the payments will be received. We utilize either the most likely amount method or expected value method to estimate the transaction price based on which method better predicts the amount of consideration expected to be received. If it is probable that a significant revenue reversal would not occur, the variable consideration is included in the transaction price.

All contingent future payments, which include research, development, regulatory, and sales-based royalty payments, were not considered in the initial analysis, as they were contingent upon options being exercised or were subject to significant risk of achievement.

Allocation of Transaction Price

We allocate the transaction price based on the estimated standalone selling price. We must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. We utilize key assumptions to determine the standalone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction, and the estimated costs. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts we would expect to receive for satisfying each performance obligation.

Recognition of Revenue

We recognize revenue at the point in time when distinct, functional licenses are transferred to the licensee and/or over the period of time which we perform research and development services. We utilize a cost-based input method to measure proportional performance, as such costs have direct relationship between our effort and the progress made towards satisfying its performance obligations to Novartis.

Accrued and Prepaid Research and Development Expenses

We record accrued expenses for estimated costs of our research and development activities which include the conduct of clinical studies and preclinical studies by third-party service providers. We record the estimated costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and include these costs in accrued liabilities in the balance sheets and within research and development expenses in the statements of operations and comprehensive loss. These costs are a significant component of our research and development expenses. We record accrued expenses for these costs based on factors such as estimates of the work completed and in accordance with agreements established with these third-party service providers. Any payments made in advance of services provided are recorded as prepaid assets, which are expensed as the contracted services are performed.

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. We make significant judgments and estimates in determining the accrued and/or prepaid balance in each reporting period. As actual costs become known, we adjust our estimates. Our accrued expenses and prepaid research and development expenses are dependent, in part, upon the receipt of timely and accurate reporting from contract research organizations, other third-party service providers and internal research and development personnel. If we under estimate or over-estimate the level of services performed or the costs of these services, our accrued expenses could differ from our estimates. For the periods presented, we have experienced no material differences between our accrued expenses and actual expenses.

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Recent Accounting Pronouncements

The information set forth under Note 2 to the financial statements under the caption “Recently Issued Accounting Pronouncements” is incorporated herein by reference.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We have operations both within the U.S. and abroad and we are exposed to market risks in the ordinary course of our business. These risks include fluctuations in interest rates and foreign currency exchange rates, and to a lesser extent, inflation risk.

Interest rate fluctuation risk

Our exposure to market risk for changes in interest rates relates primarily to our short-term investment portfolio. The primary objective of our short-term investment portfolio is to preserve principal while at the same time maximizing the income we receive from our investments without significantly increasing risk. At December 31, 2023 and 2022, we had cash and cash equivalents, restricted cash and short-term investments of $495.7 million and $331.2 million, respectively, which consisted of cash, money market funds, U.S. Treasury securities, U.S. Government Agency securities, and highly rated investment grade corporate debt securities.

Under the Oxford Loan Agreement, we had a $10.0 million term loan outstanding as of December 31, 2023 which is subject to the movement in interest rates, however the exposure to increased rates is capped at 2.0%.

Due to the short-term maturities of our cash equivalents and short-term investments and the cap on the interest rate associated with the Oxford Loan Agreement, an immediate 100 basis point change in interest rates would not have a material effect on our financial condition.

Foreign currency exchange risk

Most of our operating expenses are denominated in U.S. dollars and, as a result, we have not experienced significant foreign currency transaction gains and losses to date. We have limited foreign currency exposure associated with our operating expenses. Our exposures are primarily limited to fluctuations in the Swiss Franc, Canadian dollar and Euro. We do not anticipate that foreign currency transaction gains or losses will be significant at our current level of operations. However, our operations may become subject to more significant fluctuations in foreign currency exchange rates in the future if we continue to contract with vendors outside of the U.S. and expand our operations internationally.

Inflation risk

To date, we do not believe that inflation has had a material effect on our business, financial condition, results of operations or future prospects. However, if current inflationary pressures are sustained for a prolonged period of time, the cost projections associated with our development plans may be impacted as well as the success of businesses from which we procure services, which could harm our business, results of operations, financial condition or future prospects.

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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

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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,

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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.

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Pliant Therapeutics, Inc.

Balance Sheets

(In thousands, except number of shares and per share amounts)

Assets

Current assets

Accounts receivable — 1,983

Tax credit receivable — 83

Prepaid expenses and other current assets (Note 5) 11,257 7,058

Operating lease right-of-use assets 1,211 5,422

Restricted cash 1,482 —

Other non-current assets 392 394

Liabilities and stockholders’ equity

Current liabilities

Lease liabilities, non-current — 3,429

Commitments and Contingencies (Note 13)

Stockholders’ equity

Accumulated other comprehensive gain (loss) 345 (1,958)

Total liabilities and stockholders’ equity $ 512,154 $ 350,613

The accompanying notes are an integral part of these financial statements.

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Pliant Therapeutics, Inc.

Statements of Operations and Comprehensive Gain (Loss)

(In thousands, except number of shares and per share amounts)

Year Ended December 31,

Operating expenses:

Net loss per share - basic and diluted $ (2.75) $ (2.94) $ (2.71)

Comprehensive loss:

Net unrealized gain (loss) on short-term investments 2,303 (1,757) (169)

Total other comprehensive gain (loss) 2,303 (1,757) (169)

The accompanying notes are an integral part of these financial statements.

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Pliant Therapeutics, Inc.

Statements of Stockholders’ Equity

(In thousands, except number of shares and per share amounts)

Common Stock

Shares Amount

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)

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)

Stock-based compensation expense — — 44,483 — — 44,483

Net unrealized gain on short-term investments — — — 2,303 — 2,303

The accompanying notes are an integral part of these financial statements.

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Pliant Therapeutics, Inc.

Statements of Cash Flows

(In thousands)

Year Ended December 31,

Cash flows from operating activities

Adjustments to reconcile net loss to net cash used in operating activities:

Changes in operating assets and liabilities:

Prepaid expenses and other current assets (3,735) (294) (2,266)

Other non-current assets — 201 70

Cash flows from investing activities

Purchase of property and equipment (921) (1,760) (1,953)

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 debt issuance costs — (150) —

Proceeds from term loan — 10,000 —

Net increase (decrease) in cash and cash equivalents 31,032 (17,981) 783

Supplemental disclosures of cash flow information:

Cash paid for interest $ 1,149 $ 615 $ —

Restricted cash 1,482 — —

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

Supplemental disclosures of cash flow information related to leases:

The accompanying notes are an integral part of these financial statements.

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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

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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”)

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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.

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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

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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

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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

In 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).

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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):

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.

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The following summarizes the remaining contractual maturities of the Company’s short-term investments as of December 31, 2023:

AdjustedCost MarketValue

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,

Construction-in-progress 52 66

Computer equipment and software 124 30

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,

Prepaid research and development $ 3,403 $ 3,421

Total prepaid expenses and other current assets $ 11,257 $ 7,058

6. Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):

December 31,

Accrued compensation and benefits $ 9,042 $ 7,200

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

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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):

Thereafter —

Less: unamortized debt issuance costs (106)

Accretion of final payment 160

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

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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,

*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.

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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,

Min Max Min Max Min Max

Expected dividend — — — — — —

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

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.

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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

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

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

Vested — —

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

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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,

Expected term of options (in years) 0.50 0.50 0.50

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,

Restricted stock awards $ — $ 36 $ 182

Performance-based restricted stock units 12,021 7,390 —

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.

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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,

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,

Deferred tax assets:

Deferred tax liabilities:

Total deferred tax liabilities (1,060) (2,397)

Net deferred taxes $ — $ —

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

December 31, 2023 Expiration Year

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

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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,

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,

Additions based on tax positions related to current year 2,475 1,547

Additions for tax positions of prior year 303 144

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.

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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

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,

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,

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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 vest 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,

Unvested restricted shares — — 21,841

*PSUs outstanding based on target level of achievement of 100%.

Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure.

None.

Item 9A. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed in our reports under the Securities Exchange Act of 1934, as amended, or the Exchange Act, and the rules and regulations thereunder, is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow for timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives, and management is required to apply its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

As required by Rule 13a-15(b) under the Exchange Act, our management, under the supervision and with the participation of our principal executive officer and principal financial officer, has evaluated the effectiveness of the design and operation of our disclosure controls and procedures (as such term is defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) as of December 31, 2023. Based on such evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that, as of December 31, 2023, our disclosure controls and procedures were effective at the reasonable assurance level.

Management's Annual Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is a process designed by, or under the supervision of, our Chief Executive Officer and Chief Financial Officer to provide reasonable assurance regarding the reliability of financial reporting and the

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preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that

(1) pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of our assets;

(2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that our receipts and expenditures are being made only in accordance with authorizations of our management and directors; and

(3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on the financial statements.

Under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting based on criteria established in “Internal Control—Integrated Framework (2013)” issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Our management concluded that our internal control over financial reporting was effective as of December 31, 2023.

Our independent registered public accounting firm, Deloitte & Touche LLP, issued an attestation report on our internal control over financial reporting. See below.

Limitations on Effectiveness of Controls and Procedures and Internal Control over Financial Reporting

In designing and evaluating the disclosure controls and procedures and internal control over financial reporting, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of disclosure controls and procedures and internal control over financial reporting must reflect the fact that there are resource constraints and that management is required to apply judgment in evaluating the benefits of possible controls and procedures relative to their costs.

Changes in Internal Control Over Financial Reporting

We continuously seek to improve the efficiency and effectiveness of our internal controls. This results in refinements to processes throughout our company. There were no changes in our internal controls over financial reporting identified in connection with the evaluation required by Rule 13a-15(d) and 15d-15(d) of the Exchange Act that occurred during the quarter ended December 31, 2023 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the stockholders and the Board of Directors of Pliant Therapeutics, Inc.

Opinion on Internal Control over Financial Reporting

We have audited the internal control over financial reporting of Pliant Therapeutics, Inc. (the “Company”) 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 (COSO). In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework (2013) issued by COSO.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the financial statements as of and for the year ended December 31, 2023, of the Company and our report dated February 27, 2024, expressed an unqualified opinion on those financial statements.

Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management's Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit. 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 audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial

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reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ Deloitte & Touche LLP

San Francisco, California

February 27, 2024

Item 9B. Other Information.

Rule 10b5-1 Trading Arrangements

Other than those listed below, none of the Company’s directors or officers adopted, modified or terminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement during the three months ended December 31, 2023, as such terms are defined under Item 408(a) of Regulation S-K.

On October 4, 2023, Mike Ouimette, our General Counsel, entered into a trading plan, or the Ouimette 10b5-1 Sales Plan, intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. Under the Ouimette 10b5-1 Sales Plan, an aggregate of 57,074 shares of the Company’s common stockand up to 33% of the net shares Mr. Ouimette may receive from the vesting of certain outstanding RSU and PSU awards from time to time between January 16, 2024 and July 1, 2024 (the “Ouimette Authorized Shares”) may be sold. Due to vesting conditions of the awards and the number of shares withheld for taxes, to be determined only on the vesting date and market conditions, the number of shares actually sold under the Ouimette 10b5-1 Sales Plan may be less than the maximum number of shares that can be sold. The Ouimette 10b5-1 Sales Plan, which was entered into during an open trading window under the Company’s insider trading policy, will be in effect until the earlier of (1) December 31, 2024, or (2) the date on which all Ouimette Authorized Shares have been sold under the Ouimette 10b5-1 Sales Plan.

On December 7, 2023, Eric Lefebvre, our Chief Medical Officer, entered into a trading plan, or the Lefebvre 10b5-1 Sales Plan, intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. Under the Lefebvre 10b5-1 Sales Plan, an aggregate of 111,781 shares of the Company’s common stock may be sold (such aggregate amount, which may be reduced by any shares sold prior pursuant to a prior trading plan adopted by Dr. Lefebvre on December 13, 2022 and prior to initiation of sales pursuant to the Lefebvre 10b5-1 Sales Plan, the “Lefebvre Authorized Shares”). The Lefebvre 10b5-1 Sales Plan, which was entered into during an open trading window under the Company’s insider trading policy, will be in effect until the earlier of (1) March 7, 2025, or (2) the date on which all Lefebvre Authorized Shares have been sold under the Lefebvre 10b5-1 Sales Plan.

On December 13, 2023, Bernard Coulie, our Chief Executive Officer, entered into a trading plan, or the Coulie 10b5-1 Sales Plan, intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. Under the Coulie 10b5-1 Sales Plan, an aggregate of 80,000 shares of the Company’s common stock may be sold. The Coulie 10b5-1 Sales Plan, which was entered into during an open trading window under the Company’s insider trading policy, will be in effect until the earlier of (1) December 31, 2024, or (2) the date on which the maximum number of shares of the Company’s common stock have been sold under the Coulie 10b5-1 Sales Plan.

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Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

Not applicable.

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PART III

Item 10. Directors, Executive Officers and Corporate Governance.

Information required by this item will be set forth in our Proxy Statement for our 2024 Annual Meeting of Stockholders and is incorporated herein by reference. Information required by this item regarding compliance with Section 16(a) of the Exchange Act will be set forth in our Proxy Statement and is incorporated herein by reference.

Our written code of business conduct and ethics (the “Code of Conduct”) applies to all of our employees, officers and directors, including our principal executive officer, principal financial officer and principal accounting officer or controller. The Code of Conduct is available on our corporate website at https://pliantrx.com. If we make any substantive amendments to our Code of Conduct or grant any of our directors or executive officers any waiver, including any implicit waiver, from a provision of our Code of Conduct, we will disclose the nature of the amendment or waiver on our website or in a Current Report on Form 8-K.

Item 11. Executive Compensation.

Information required by this item will be set forth in our Proxy Statement and is incorporated by reference.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

Information required by this item will be set forth in our Proxy Statement and is incorporated by reference.

Item 13. Certain Relationships and Related Transactions, and Director Independence.

Information required by this item will be set forth in our Proxy Statement and is incorporated by reference.

Item 14. Principal Accounting Fees and Services.

Information required by this item will be set forth in our Proxy Statement and is incorporated by reference.

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PART IV

Item 15. Exhibits, Financial Statement Schedules.

(a)The following documents are filed as part of this Annual Report:

1.Financial Statements. See Index to Financial Statements in Part II Item 8 of this Annual Report on Form 10-K.

2.Financial Statement Schedules. None. All financial statement schedules are omitted because they are not applicable, notrequired under the instructions, or the requested information is included in the financial statements or notes thereto.