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

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and related notes included elsewhere in this annual report. This discussion and analysis contains forward-looking statements based upon our current beliefs, plans and expectations that involve risks, uncertainties and assumptions. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth under “Risk Factors” or in other parts of this annual report.

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Overview

We are a clinical-stage, clinical biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of PH, including PAH and PH-ILD. Our goal is to be an industry leader in, and to enhance the lives of patients living with PH. In May 2024, we entered into the Chiesi Collaboration Agreement focused on the development and commercialization of seralutinib. In December 2022, we announced positive topline results from the Phase 2 TORREY Study in PAH patients. In February 2026, we announced topline results from the Phase 3 PROSERA Study in PAH patients. Seralutinib demonstrated a placebo-adjusted improvement in the primary endpoint, 6MWD at Week 24, of 13.3 meters (p = 0.0320), missing the prespecified alpha threshold of 0.025. We believe seralutinib demonstrates a risk benefit profile that supports continued regulatory dialogue, and we plan to engage with the FDA, including through requesting a Type C meeting, to understand their perspective on the totality of the PROSERA and TORREY datasets and potential regulatory paths forward. In addition to PAH, we believe that seralutinib holds potential as a therapeutic for the treatment of PH-ILD. In October 2025, we activated the first clinical site for the global registrational Phase 3 SERANATA Study for the treatment of PH-ILD. Enrollment in the SERANATA Study was paused in February 2026 to support disciplined resource allocation and to evaluate the implications of PROSERA as we engage with regulators. We have assembled a deeply experienced and highly skilled group of industry veterans, scientists, clinicians and key opinion leaders from leading biotechnology and pharmaceutical companies, as well as leading academic centers from around the world. Our employees are a team of highly dedicated, passionate individuals who pride themselves on a culture of respect, humility, transparency, inclusion, dedication, collaboration and fun. Our ultimate goal is to enhance and extend the lives of patients.

We were incorporated in October 2015 and commenced operations in 2017. To date, we have focused primarily on organizing and staffing our company, business planning, raising capital, identifying, acquiring and in-licensing our product candidates and conducting preclinical studies and clinical trials. We have funded our operations primarily through equity financings and the Chiesi Collaboration Agreement. We raised $1,396.9 million from October 2017 through December 31, 2025 through the sale of Series A and Series B convertible preferred stock, issuance of convertible notes, proceeds from our IPO completed in February 2019, proceeds from the 2027 Notes (as defined below), issuances of common stock in May 2020 and July 2022, issuance of common stock and accompanying warrants in July 2023 and entry into the Chiesi Collaboration Agreement in May 2024. As of December 31, 2025, we had $136.9 million in cash, cash equivalents and marketable securities.

We have incurred significant operating losses since our inception and expect to continue to incur significant operating losses for the foreseeable future. For the years ended December 31, 2025 and 2024, our net loss was $170.4 million and $56.5 million, respectively. As of December 31, 2025, we had an accumulated deficit of $1,438.9 million. We expect to incur expenses and operating losses for the foreseeable future as we continue our development of and seek regulatory approvals for seralutinib, including the conduct of ongoing and future clinical trials and other research and development activities; and as we hire additional personnel, protect our intellectual property and incur additional costs associated with being a public company. In addition, as seralutinib progresses through development and toward commercialization, we will need to make milestone payments to Pulmokine from whom we have in-licensed seralutinib. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending in particular on the timing of our clinical trials and preclinical studies and our expenditures on other research and development activities.

On May 3, 2024, we announced a strategic global partnership with Chiesi. Under the terms of the Chiesi Collaboration Agreement, we granted Chiesi exclusive licenses for the worldwide development, manufacture and commercialization of seralutinib and licensed products and an Equity Option to purchase our common stock, which expired in November 2025 and is no longer exercisable. The total potential transaction value includes the one-time $160.0 million development cost reimbursement payment for licenses, research and development funding, and certain regulatory and commercial milestones. We and Chiesi share equally in the costs of ongoing global seralutinib clinical development and the costs of commercialization in the U.S. Territory, with the exception of the PROSERA Phase 3 study, for which we bear all costs. We are also eligible for double-digit royalties in the mid-to-high teens percentage on tiers of annual net sales outside of the U.S. Territory and to an equal share of profits and losses from the commercialization of seralutinib and licensed products in the U.S. For additional information regarding the collaboration agreement, as well as our license agreement with Pulmokine, see the section titled “Business—License and Collaboration Agreements” in this annual report.

We do not expect to generate any revenue from product sales unless and until we successfully complete development and obtain regulatory approval for seralutinib, which we expect will take a number of years, if at all. If we obtain regulatory approval for seralutinib, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, until such time as we can generate substantial product revenues to support our cost structure, if ever, we expect to finance our cash needs through equity offerings, debt financings or other capital sources, including potentially collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into

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such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional capital when needed, we could be forced to delay, limit, reduce or terminate seralutinib development or future commercialization efforts or grant additional rights to develop and market seralutinib even if we would otherwise prefer to retain such right.

Components of Results of Operations

Revenue

To date, we have generated all of our revenue from the Chiesi Collaboration Agreement. Our revenue consists of a one-time development cost reimbursement payment for licenses and ongoing cost-sharing payments for performance of research and development services classified as revenue from contracts with collaborators.

In the future, we may generate revenue from a combination of license fees and other upfront payments, other funded research and development agreements, milestone payments, product sales, other third-party funding, U.S. profit/loss share and royalties in connection with strategic alliances. We expect that any revenue we generate will fluctuate from quarter-to-quarter as a result of the timing of performance of research and development services, the timing of our achievement of regulatory and commercialization milestones, the timing and amount of payments relating to such milestones and the extent to which any of our products are approved and successfully commercialized. If we are unable to fund our development costs or we are unable to develop product candidates in a timely manner or obtain regulatory approval for them, our ability to generate future revenues and our results of operations and financial position would be adversely affected.

Operating expenses

Research and development

Research and development expenses relate primarily to preclinical and clinical development of seralutinib, as well as our discontinued clinical product candidates. Research and development expenses are recognized as incurred and payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received.

Research and development expenses include or could include:

•salaries, payroll taxes, employee benefits, and stock-based compensation charges for those individuals involved in research and development efforts;

•external research and development expenses incurred under agreements with contract research organizations, or CROs, investigative sites and consultants to conduct our clinical trials and preclinical and non-clinical studies;

•laboratory supplies;

•costs related to manufacturing our product candidates for clinical trials and preclinical studies, including fees paid to third-party manufacturers;

•costs related to compliance with regulatory requirements; and

•facilities, depreciation and other allocated expenses, which include direct and allocated expenses for rent, maintenance of facilities, insurance, equipment and other supplies.

Our direct research and development expenses consist principally of external costs, such as fees paid to CROs, investigative sites and consultants in connection with our clinical trials, preclinical and non-clinical studies, and costs related to manufacturing clinical trial materials. We deploy our personnel and facility related resources across all of our research and development activities. We track external costs and personnel expense on a program-by-program basis and allocate common expenses, such as facility related resources, to each program based on the personnel resources allocated to such program. Stock-based compensation and personnel and common expenses not attributable to a specific program are considered unallocated research and development expenses. We categorize Terminated Programs as any research and development expenses attributable to our clinical stage product candidates that were terminated prior to December 31, 2023 or any research and development expenses that are not directly allocated to seralutinib.

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We expect to incur research and development expenses for the foreseeable future as we continue the development of seralutinib. We cannot determine with certainty the timing of initiation, the duration or the completion costs of current or future preclinical studies and clinical trials of seralutinib due to the inherently unpredictable nature of preclinical and clinical development. Clinical and preclinical development timelines, the probability of success and development costs can differ materially from expectations. We anticipate that we will make determinations as to how much funding to direct to seralutinib on an ongoing basis in response to the results of ongoing and future preclinical studies and clinical trials, regulatory developments and our ongoing assessments as to seralutinib's commercial potential. We will need to raise substantial additional capital in the future.

Our clinical development costs may vary significantly based on factors such as:

•per patient trial costs;

•the number of trials required for approval;

•the number of sites included in the trials;

•the countries in which the trials are conducted;

•the length of time required to enroll eligible patients;

•the number of patients that participate in the trials;

•the number of doses that patients receive;

•the drop-out or discontinuation rates of patients;

•potential additional safety monitoring requested by regulatory agencies;

•the duration of patient participation in the trials and follow-up;

•the cost and timing of manufacturing seralutinib;

•the costs incurred as a result of health epidemics and pandemics and clinical site staff shortages, including clinical trial delays;

•the phase 3 stage of development for seralutinib; and

•the efficacy and safety profile of seralutinib.

In process research and development

In process research and development, or IPR&D, expenses include IPR&D acquired as part of an asset acquisition or in-license, for which there is no alternative future use, and the value of the right to acquire Respira Therapeutics via a merger, or the Respira Merger Option, with Prana Bio, the 100% owner of Respira Therapeutics, and are expensed as incurred.

General and administrative

General and administrative expenses consist primarily of salaries and employee-related costs, including stock-based compensation, for personnel in executive, finance and other administrative functions. Other significant costs include facility-related costs, legal fees relating to intellectual property and corporate matters, professional fees for accounting and consulting services, insurance costs and commercial planning expenses. Subject to obtaining clarity on potential regulatory paths forward, we anticipate that our general and administrative expenses may increase in the future to support our continued research and development and commercial planning activities and, if seralutinib receives marketing approval, commercialization activities.

We expect to incur general and administrative expenses for the foreseeable future to support our current infrastructure and continued costs of operating as a public company. These expenses will likely include audit, legal, regulatory, and tax-related services associated with maintaining compliance with exchange listing and SEC requirements, director and officer insurance premiums, as well as commercial preparedness, corporate strategy, business development, corporate communications and investor relations costs associated with operating as a public company.

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Other income (expense), net

Other income (expense), net consists of (1) interest income on our cash, cash equivalents and marketable securities, (2) investment accretion, (3) interest expense related to our Credit Facility, prior to its termination and the 2027 Notes, (4) research and development tax credit and (5) other miscellaneous income (expense).

Provision for income taxes

Our tax provision from income taxes is determined using an estimate of our annual effective tax rate, adjusted for discrete items, if any, that are taken into account in the relevant period.

Critical Accounting Policies and Estimates

Our management’s discussion and analysis of our financial condition and results of operations are based on our consolidated financial statements, which have been prepared in accordance with generally accepted accounting principles in the United States, or GAAP. The preparation of these financial statements requires us to make judgments and estimates that affect the reported amounts of assets, liabilities, revenue, expenses and the disclosure of contingent assets and liabilities in our consolidated financial statements. We base our estimates on historical experience, known trends and events, and various other factors that are believed to be reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions (See Note 2 to our consolidated financial statements).

Accrued expenses

As part of the process of preparing our consolidated financial statements, we are required to estimate our accrued expenses as of each balance sheet date. This process involves reviewing open contracts and purchase orders, communicating with our personnel to identify services that have been performed on our behalf and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual cost. We make estimates of our accrued expenses as of each balance sheet date based on facts and circumstances known to us at that time. We periodically confirm the accuracy of our estimates with the service providers and make adjustments if necessary. The significant estimates in our accrued research and development expenses include the costs incurred for services performed by our vendors in connection with research and development activities for which we have not yet been invoiced.

We base our expenses related to research and development activities on our estimates of the services received and efforts expended pursuant to quotes and contracts with vendors that conduct research and development on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the research and development expense. In accruing service fees, we estimate the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrual or prepaid expense accordingly. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made.

Although we do not expect our estimates to be materially different from amounts actually incurred, if our estimates of the status and timing of services performed differ from the actual status and timing of services performed, it could result in us reporting amounts that are too high or too low in any particular period. To date, there have been no material differences between our estimates of such expenses and the amounts actually incurred.

Collaborative Arrangements

We assess whether our licensing and other agreements are collaborative arrangements based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. For arrangements that we determine are collaborations, we identify each unit of account, and then determine whether a customer relationship exists for that unit of account. If we determine a performance obligation within the collaborative arrangement to be with a customer, we apply our revenue recognition accounting policy. If a portion of a distinct bundle of goods or services within the collaborative arrangement is not with a customer, we apply recognition and measurement based on an analogy to authoritative accounting literature or, if there is no appropriate analogy, a reasonable, rational and consistently applied accounting policy election. To the extent the arrangement is within the scope of Accounting Standards Codification, or ASC, Topic 808, we assess whether aspects of the arrangement between us and the collaboration partner are within the scope of other accounting literature. If we conclude that some or all aspects of the arrangement represent a

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transaction with a customer, we account for those aspects of the arrangement within the scope of ASC Topic 606, Revenue from Contracts with Customers (ASC 606).

Revenue Recognition

We recognize revenue in accordance with ASC 606, Revenue from Contracts with Customers, or Topic 606, which applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under Topic 606, we recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for contracts with customers, 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) the entity satisfies 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. At contract inception, once the contract is determined to be within the scope of Topic 606, 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, reduced by a consideration payable to a customer, that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. We utilize key assumptions to determine a stand-alone selling price for performance obligations, which may include forecasted revenues or costs, expected development timelines, discount rates and probabilities of technical and regulatory success.

Results of Operations for the Years Ended December 31, 2025 and 2024

The following table sets forth our selected statements of operations data for the years ended December 31, 2025 and 2024:

(in thousands)

Revenue:

Revenue from sale of licenses $ — $ 90,682 $ (90,682)

Operating expenses:

In process research and development 7,475 — 7,475

Other income (expense)

Provision (benefit) for income taxes (88) 893 (981)

Operating Expenses

Revenue

Our revenue is generated from our ongoing collaboration with Chiesi and consists of a one-time development cost reimbursement payment for the licenses and ongoing cost-sharing payments for performance of research and development and pre-commercial services. Revenue was $48.5 million for the year ended December 31, 2025, compared to $114.7 million for the year ended December 31, 2024, for a decrease of $66.2 million, which was primarily attributable to a decrease of $90.7

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million from sale of licenses, offset by an increase of $24.5 million of revenue associated with performance of research and development and pre-commercial services.

Research and development expenses

Research and development expenses were $174.1 million for the year ended December 31, 2025, compared to $138.5 million for the year ended December 31, 2024, for an increase of $35.6 million, which was primarily attributable to an increase of $44.4 million of costs associated with clinical trials for seralutinib, offset by a decrease of $9.2 million of costs associated with preclinical studies and clinical trials for terminated programs.

The following table shows our research and development expenses by program for the years ended December 31, 2025 and 2024:

Years Ended December 31,

(in thousands)

Other programs 458 —

Terminated programs — 9,240

In process research and development expenses

There were no IPR&D expenses for the year ended December 31, 2024. IPR&D expenses for the year ended December 31, 2025 were $7.5 million, which was attributable to the acquisition of Respira Merger Option.

General and administrative expenses

General and administrative expenses were $37.6 million for the year ended December 31, 2025, compared to $36.1 million for the year ended December 31, 2024, for an increase of $1.5 million, which was primarily attributable to a $6.3 million increase in commercial planning expense and a $1.2 million increase in personnel expense, offset by a $5.1 million decrease in stock-based compensation expense and a decrease of $1.1 million in facilities expense.

Other income (expense), net

Other income, net was $0.3 million for the year ended December 31, 2025, compared to other income, net of $4.3 million for the year ended December 31, 2024, for a decrease of $4.0 million, which was primarily attributable to a $6.4 million decrease in investment accretion, offset by a $0.5 million decrease in interest expense and a $1.1 million increase in other income primarily related to $1.4 million of employee retention credit under the CARES Act.

Provision (benefit) for income taxes

There was $0.1 million tax benefit for the year ended December 31, 2025. For the year ended December 31, 2024, the tax expense was $0.9 million, which was primarily attributable to the treatment of the Chiesi income and a partial release of the valuation allowance.

Results of Operations for the Years Ended December 31, 2024 and 2023

The discussion of our financial condition and results of operations for the year ended December 31, 2024 and the comparison of 2024 and 2023 results included in Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations in our Annual Report on Form 10-K for the year ended December 31, 2024 is incorporated by reference into this MD&A.

Liquidity and Capital Resources

We have incurred substantial operating losses since our inception and expect to continue to incur significant operating losses for the foreseeable future and may never become profitable. As of December 31, 2025 and 2024, we had an accumulated deficit of $1,438.9 million and $1,268.6 million, respectively.

Our primary use of cash is to fund operating expenses, which consist primarily of research and development expenditures, and to a lesser extent, general and administrative expenditures, including commercial planning expenditures. Cash

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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 and accrued expenses. We may also use cash on hand to repurchase 2027 Notes through open-market transactions, including through a Rule 10b5-1 trading plan to facilitate open-market repurchases, or otherwise, from time to time.

Under our license agreement with Pulmokine, we have payment obligations that are contingent upon future events such as our achievement of specified development, regulatory and commercial milestones and are required to make royalty payments in connection with the sale of products developed under the agreement. As of December 31, 2025, we were unable to estimate the timing or likelihood of achieving the milestones or making future product sales. Other contractual obligations include future payments under the 2027 Notes and existing operating leases.

From our inception through the year ended December 31, 2025, our operations have been financed primarily by proceeds of $1,396.9 million from the sale of Series A and Series B convertible preferred stock, proceeds from our IPO, proceeds from the 2027 Notes, proceeds from issuance of common stock in May 2020 and July 2022, proceeds from issuance of common stock and accompanying warrants in July 2023 and the Chiesi Collaboration Agreement. In addition, we have received $36.4 million as of December 31, 2025 through reimbursement related to the Chiesi Collaboration Agreement. As of December 31, 2025, we had cash, cash equivalents and marketable securities of $136.9 million. Cash in excess of immediate requirements is invested in accordance with our investment policy, primarily with a view to capital preservation and liquidity.

On April 10, 2020, we filed a registration statement on Form S-3, or the 2020 Shelf Registration Statement, covering the offering from time to time of common stock, preferred stock, debt securities, warrants and units, which registration statement became automatically effective on April 10, 2020.

On May 21, 2020, we issued $200.0 million aggregate principal amount 5.00% convertible senior notes due 2027 in a registered public offering, or the 2027 Notes. The interest rate on the 2027 Notes is fixed at 5.00% per annum. Interest is payable semi-annually in arrears on June 1 and December 1 of each year commencing on December 1, 2020. The total net proceeds from the 2027 Notes, after deducting the underwriting discounts and commissions and other offering costs, were approximately $193.6 million. Concurrent with the registered underwritten public offering of the 2027 Notes, we completed an underwritten public offering of 9,433,963 shares of our common stock. We received net proceeds of $117.1 million, after deducting underwriting discounts and commissions and other offering costs. Our concurrent offerings of 2027 Notes and common stock were registered pursuant to the 2020 Shelf Registration Statement.

On July 15, 2022, we completed a private placement of 16,649,365 shares of our common stock. The aggregate gross proceeds for the private placement were approximately $120.1 million, before deducting offering expenses. On August 9, 2022, we filed a registration statement on Form S-3 registering the resale of the shares of common stock issued in the private placement, which became automatically effective on August 9, 2022.

On July 24, 2023, we completed a private placement of 129,869,440 shares of our common stock and 32,467,360 accompanying warrants. The aggregate gross proceeds for the private placement were $212.1 million, before deducting offering expenses. On August 18, 2023, we filed a registration statement on Form S-3 registering the resale of the shares of common stock and shares of common stock issuable upon the exercise of warrants issued in the private placement, which was declared effective on August 28, 2023.

On May 3, 2024, we entered into the Chiesi Collaboration Agreement. In consideration and as reimbursement for our development costs, Chiesi paid us an up-front, nonrefundable payment of $160.0 million. In addition, we and Chiesi share equally in the costs of ongoing global seralutinib clinical development, with the exception of the PROSERA Phase 3 study, and the costs of commercialization in the U.S. Territory. For the year ended on December 31, 2025, we received cost-sharing payments from Chiesi in the amount of $28.6 million.

On January 28, 2026, we filed a registration statement on Form S-3, or the 2026 Shelf Registration Statement, covering the offering from time to time of common stock, preferred stock, debt securities, warrants and units, which registration statement became automatically effective on January 28, 2026.

Additional information about our long-term borrowings is presented in Note 5 “Indebtedness” and operating leases is presented in Note 11 "Commitments and Contingencies" to the Notes to Consolidated Financial Statements included in Part II, Item 8, of this Form 10-K, incorporated herein by this reference.

The opinion of our independent registered public accounting firm on our audited financial statements as of and for the years ended December 31, 2025 and 2024 contains an explanatory paragraph regarding substantial doubt about our ability to continue as a going concern. Future reports on our financial statements may include an explanatory paragraph with

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respect to our ability to continue as a going concern. Our audited consolidated financial statements as of and for the years ended December 31, 2025 and 2024 included in this Annual Report do not include any adjustments relating to the recoverability and classification of recorded asset amounts or amounts of liabilities that might be necessary should we be unable to continue our operations.

The following table shows a summary of our cash flows for each of the years shown below:

Years Ended December 31,

(in thousands)

Effect of exchange rate changes on cash and cash equivalents 141 (102) 110

Operating activities

During the year ended December 31, 2025, operating activities used approximately $171.3 million of cash, primarily resulting from a net loss of $170.4 million and changes in prepaid expenses and other current assets of $8.5 million and amortization of premium on investments of $7.3 million, reduced by changes in accrued research and development expenses of $11.2 million and stock-based compensation expense of $10.6 million.

During the year ended December 31, 2024, operating activities used approximately $3.5 million of cash, primarily resulting from a net loss of $56.5 million and amortization of premium on investments, net of accretion of discount, of $13.1 million, reduced by stock-based compensation expense of $20.6 million and changes in contract liabilities of $55.9 million.

During the year ended December 31, 2023, operating activities used approximately $159.2 million of cash, primarily resulting from a net loss of $179.8 million, changes in accrued research and development expenses of $7.8 million and amortization of premium on investments of $9.5 million, reduced by stock-based compensation expense of $28.5 million and in process research and development expense of $10.0 million.

Investing activities

During the year ended December 31, 2025, investing activities provided approximately $156.4 million of cash, primarily resulting from the maturities of marketable securities of $376.4 million, offset by purchases of marketable securities of $227.1 million.

During the year ended December 31, 2024, investing activities provided approximately $29.0 million of cash, primarily resulting from the maturities of marketable securities of $523.8 million, offset by purchases of marketable securities of $494.8 million.

During the year ended December 31, 2023, investing activities used approximately $111.0 million of cash, primarily resulting from the purchase of marketable securities of $441.7 million, offset by the maturities of marketable securities of $330.7 million.

Financing activities

During the year ended December 31, 2025, financing activities provided $6.4 million of cash, resulting from the proceeds from the exercise of warrants of $3.7 million, the proceeds from the exercise of stock options of $1.9 million and the proceeds from the issuance of common stock pursuant to the ESPP of $0.8 million.

During the year ended December 31, 2024, financing activities used $11.5 million of cash, resulting from the principal repayment of long-term debt of $12.6 million, reduced by the proceeds from the issuance of equity option pursuant to stock purchase agreement with Chiesi of $0.5 million and the proceeds from issuance of common stock pursuant to the ESPP of $0.6 million.

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During the year ended December 31, 2023, financing activities provided $190.2 million of cash, primarily resulting from proceeds from the issuance of common stock and warrants in a private offering of $201.3 million, reduced by the principal repayments of long-term debt of $11.6 million.

Funding requirements

Based on our current operating plan, we believe that our existing cash, cash equivalents and marketable securities, will be sufficient to fund our operations through the fourth quarter of 2026. However, our forecast of the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we expect. Additionally, the process of testing seralutinib in clinical trials and seeking regulatory approval is costly, and the timing of progress and expenses in these trials is uncertain. Pending feedback from the FDA on a potential path forward for seralutinib, we also expect that the level of spending for our ongoing and planned commercial planning activities for seralutinib may increase.

Our future capital requirements will depend on many factors, including:

•the costs, timing and outcome of regulatory review of seralutinib;

•the type, number, scope, progress, enrollment pace, expansions, results, costs and timing of, our preclinical studies and clinical trials of seralutinib which we are pursuing or may choose to pursue in the future;

•the costs and timing of manufacturing for seralutinib;

•the costs of obtaining, maintaining and enforcing our patents and other intellectual property rights;

•our efforts to enhance operational systems and hire additional personnel to satisfy our obligations as a public company, including enhanced internal controls over financial reporting;

•the costs associated with hiring additional personnel and consultants to continue the development and potential commercialization of seralutinib;

•the timing and amount of the milestone or other payments we must make to Pulmokine from whom we have in-licensed seralutinib;

•the costs and timing of establishing or securing sales and marketing capabilities if seralutinib is approved;

•our ability to achieve sufficient market acceptance, coverage and adequate reimbursement from third-party payors and adequate market share and revenue for any approved products;

•the terms and timing of establishing and maintaining collaborations, licenses and other similar arrangements;

•costs associated with any products or technologies that we may in-license or acquire; and

•any delays and cost increases that result from epidemic diseases.

Until such time as we can generate substantial product revenues to support our cost structure, if ever, we expect to finance our cash needs through equity offerings, debt financings or other capital sources, including potentially collaborations, licenses and other similar arrangements.

However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders will be or could be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our common stockholders. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise funds through collaborations, licenses and other similar arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us and/or may reduce

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the value of our common stock. Our failure to raise capital or enter into such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional capital when needed, we could be forced to delay, limit, reduce or terminate seralutinib development or future commercialization efforts or grant rights to develop and market seralutinib even if we would otherwise prefer to develop and market seralutinib ourselves.

Recent Accounting Pronouncements

See Note 2 to our consolidated financial statements included elsewhere in this annual report.

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

Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates. As of December 31, 2025 our cash and cash equivalents consisted of cash, money market funds and commercial paper, and our marketable securities consisted of commercial paper, corporate debt securities and U.S. Treasury and agency securities. We do not believe that we have a material exposure to interest rate risk. A 100 basis points change in interest rates would not have a significant impact on the total value of our portfolio.

We are exposed to market risk related to changes in foreign currency exchange rates associated with our foreign operations where we conduct business in local currencies. We also contract with vendors that are located outside of the United States and certain invoices are denominated in foreign currencies. We are subject to fluctuations in foreign currency rates in connection with these arrangements. We do not currently hedge our foreign currency exchange rate risk. As of December 31, 2025 and 2024, we had minimal assets and liabilities denominated in foreign currencies and an immediate change of 10% in the exchange rate of the foreign currencies would result in a net impact of approximately $0.1 million in our consolidated balance sheets and consolidated statement of operations and comprehensive loss.

Inflation generally affects us by increasing our cost of labor and clinical trial costs. Inflationary factors, such as increases in the cost of our materials, supplies, and overhead costs may adversely affect our operating results. Although we do not believe that inflation had a material effect on our business, financial condition or results of operations during the periods presented, we may experience adverse effects if inflation rates increase. Significant adverse changes in inflation and prices in the future could result in material losses.

Item 8. Financial Statements and Supplementary Data.

The consolidated financial statements required pursuant to this item are incorporated by reference herein from the applicable information included in Item 15 of this annual report and are presented beginning on page F-1.

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

None.

Item 9A. Controls and Procedures.

Conclusion Regarding the Effectiveness of Disclosure Controls and Procedures

We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed in our periodic and current reports that we file with the SEC 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 principal executive officer and principal financial officer, as appropriate, to allow timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, management recognized that any controls and procedures, no matter how well designed and operated, can provide only reasonable and not absolute assurance of achieving the desired control objectives. In reaching a reasonable level of assurance, management necessarily was required to apply its judgment in evaluating the cost-benefit relationship of possible controls and procedures. In addition, the design of any system of controls also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions; over time, control may become inadequate because of changes in conditions, or the degree of compliance with policies or procedures may deteriorate. Because of the inherent limitations in a cost-effective control system, misstatements due to error or fraud may occur and not be detected.

Our management, with the participation of our principal executive officer and principal financial officer, has evaluated the effectiveness of our disclosure controls and procedures as defined in Rules 13a-15(e) and 15d-15(e) under the

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Exchange Act as of the end of the period covered by this annual report. Based on such evaluation, our principal executive officer and principal financial officer have concluded that as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control Over Financial Reporting

There have been no changes in our internal control over financial reporting during the quarter ended December 31, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Management’s Annual Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act. Our 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 GAAP. 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.

Our management assessed the effectiveness of our internal control over financial reporting as of December 31, 2025 based on the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in its 2013 Internal Control — Integrated Framework. Based on this assessment, our management has concluded that our internal control over financial reporting was effective as of December 31, 2025.

Item 9B. Other Information.

During the three months ended December 31, 2025, none of our officers or directors adopted or terminated any contract, instruction or written plan for the purchase or sale of our securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any “non Rule 10b5-1 trading arrangement," except as described below:

•On October 31, 2025, Faheem Hasnain, CEO and President, adopted a Rule 10b5-1 trading arrangement providing for the sale of up to 1,125,000 shares of our common stock. The trading arrangement is intended to satisfy the affirmative defense in Rule 10b5-1(c). The duration of the trading arrangement is from March 15, 2026 until December 29, 2026, or earlier if and when all transactions under the trading arrangement are completed.

On March 16, 2026, we commenced a workforce reduction of 77 individuals, constituting approximately 48% of our workforce, to reduce our operating expenses. Our remaining management and employees will continue the development of seralutinib and explore potential regulatory paths forward. This workforce reduction is expected to be substantially completed by the end of May 2026.

In connection with the workforce reduction, on March 15, 2026, Richard Aranda, M.D., resigned from his position as the Chief Medical Officer of the Company effective as of April 15, 2026. The Company expects to execute a separation agreement with Dr. Aranda in connection with his departure, pursuant to which he will receive the severance provided under his employment agreement, in exchange for a general release of claims. Dr. Aranda will continue as a consultant to the Company to assist with transitional matters.

We currently estimate that we will incur charges associated with the workforce reduction of approximately $6.7 million primarily related to employee severance payments, benefits and related termination costs. We expect the majority of related charges to be recognized in the second and third quarters of 2026.

The estimates of the charges and expenditures that we expect to incur in connection with the workforce reduction, and the timing thereof, are subject to several assumptions and the actual amounts incurred may differ materially from these estimates. In addition, we may incur other charges or cash expenditures not currently contemplated due to unanticipated events that may occur, including in connection with the implementation of the workforce reduction.

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.

The information required by this item will be contained in our definitive proxy statement to be filed with the Securities and Exchange Commission in connection with our 2026 Annual Meeting of Stockholders, or the Definitive Proxy Statement, which is expected to be filed not later than 120 days after the end of our fiscal year ended December 31, 2025, under the headings “Election of Directors,” “Corporate Governance,” “Our Executive Officers,” and, if applicable, “Delinquent Section 16(a) Reports,” and is incorporated herein by reference.

Code of Business Conduct and Ethics

We have adopted a Code of Business Conduct and Ethics that applies to our officers, directors and employees, which is available on our website at www.gossamerbio.com. The Code of Business Conduct and Ethics contains general guidelines for conducting the business of our company consistent with the highest standards of business ethics and is intended to qualify as a “code of ethics” within the meaning of Section 406 of the Sarbanes-Oxley Act of 2002 and Item 406 of Regulation S-K. In addition, we intend to promptly disclose (1) the nature of any amendment to our Code of Business Conduct and Ethics that applies to our principal executive officer, principal financial officer, principal accounting officer or controller or persons performing similar functions and (2) the nature of any waiver, including an implicit waiver, from a provision of our code of ethics that is granted to one of these specified officers, the name of such person who is granted the waiver and the date of the waiver on our website in the future. Information contained in our website does not constitute a part of this report or our other filings with the SEC.

Insider Trading Policy

We have adopted a policy on insider trading and procedures that govern the purchase, sale, and/or other dispositions of our securities by our directors, officers, employees and other covered persons that are designed to promote compliance with insider trading laws, rules and regulations, and the Nasdaq listing rules, as applicable. A copy of our policy on insider trading is filed as Exhibit 19.1 to this annual report on Form 10-K. It is our policy to comply with U.S. insider trading laws and regulations, including with respect to transactions in our own securities.

Item 11. Executive Compensation.

The information required by this item will be set forth in the section headed “Executive Compensation and Other Information” in our Definitive Proxy Statement and is incorporated herein by reference.

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

The information required by this item will be set forth in the section headed “Security Ownership of Certain Beneficial Owners and Management” in our Definitive Proxy Statement and is incorporated herein by reference.

The information required by Item 201(d) of Regulation S-K will be set forth in the section headed "Executive Compensation and Other Information" in our Proxy Statement and is incorporated herein by reference.

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

The information required by this item will be set forth in the section headed “Certain Relationships and Related Person Transactions,” “Board Independence” and “Board Committees and Independence” in our Definitive Proxy Statement and is incorporated herein by reference.

Item 14. Principal Accounting Fees and Services.

The information required by this item will be set forth in the section headed “Independent Registered Public Accounting Firm's Fees” in our Definitive Proxy Statement and is incorporated herein by reference.

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PART IV

Item 15. Exhibits, Financial Statement Schedules.

(1)All Financial statements

The consolidated financial statements of Gossamer Bio, Inc., together with the report thereon of Ernst & Young LLP, an independent registered public accounting firm, are included in this annual report on Form 10-K beginning on page F-1.

(2)Financial statement schedules

All schedules have been omitted because the information required to be set forth therein is not applicable or is shown in the consolidated financial statements or notes thereto.

(3)Exhibits

A list of exhibits is set form on the Exhibit Index immediately preceding the signature page of this annual report on Form 10-K and is incorporated herein by reference.

Item 16. Form 10–K Summary.

None.

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Gossamer Bio, Inc.

Index to Consolidated Financial Statements

Page

Consolidated Balance Sheets F-3

Consolidated Statements of Operations and Comprehensive Loss F-4

Consolidated Statements of Stockholders’ Equity (Deficit) F-5

Consolidated Statements of Cash Flows F-6

Notes to Consolidated Financial Statements F-7

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Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of Gossamer Bio, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Gossamer Bio, Inc. (the Company) as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, stockholders' equity (deficit) and cash flows for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with U.S. generally accepted accounting principles.

The Company's Ability to Continue as a Going Concern

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As discussed in Note 1 to the financial statements, the Company has suffered recurring losses from operations and has stated that substantial doubt exists about the Company’s ability to continue as a going concern. Management's evaluation of the events and conditions and management’s plans regarding these matters are also described in Note 1. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

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 Public Company Accounting Oversight Board (United States) (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. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

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 the critical audit matter does not alter in any way our opinion on the consolidated 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 account or disclosure to which it relates.

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Accrued research and development expenses

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 2018.

San Diego, California

March 17, 2026

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GOSSAMER BIO, INC.

Consolidated Balance Sheets

(in thousands, except share and par value amounts)

December 31,

ASSETS

Current assets

Receivable from contracts with collaborators 12,227 5,338

Prepaid expenses and other current assets 18,485 10,032

Property and equipment, net 64 10

Operating lease right-of-use assets 4,133 5,111

LIABILITIES AND STOCKHOLDERS' EQUITY (DEFICIT)

Current liabilities

Accrued research and development expenses 21,662 10,455

Accrued expenses and other current liabilities 15,827 15,186

Operating lease liabilities - long-term 3,460 4,398

Commitments and contingencies (Note 11)

Stockholders' equity (deficit)

Accumulated other comprehensive income (loss) (5,149) 1,189

Total liabilities and stockholders' equity (deficit) $ 172,249 $ 315,292

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

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GOSSAMER BIO, INC.

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except share and per share amounts)

Year Ended December 31,

Revenue:

Revenue from sale of licenses $ — $ 90,682 $ —

Revenue from contracts with collaborators 48,471 24,019 —

Operating expenses:

In process research and development 7,475 — 10,000

Other income (expense)

Provision (benefit) for income taxes (88) 893 —

Other comprehensive income (loss):

Unrealized income (loss) on marketable securities (90) 89 191

Net loss per share, basic and diluted $ (0.75) $ (0.25) $ (1.18)

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

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GOSSAMER BIO, INC.

Consolidated Statements of Stockholders’ Equity (Deficit)

(in thousands, except share amounts)

Shares Amount

Vesting of restricted stock 55,225 — — — — —

Issuance of common stock for restricted stock units vested 724,674 — — — — —

Other comprehensive income — — — — 224 224

Issuance of common stock for restricted stock units vested 427,698 — — — — —

Other comprehensive income — — — — 1,539 1,539

Other comprehensive loss — — — — (6,338) (6,338)

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

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GOSSAMER BIO, INC.

Consolidated 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:

In process research and development expenses 7,475 — 10,000

Amortization of operating lease right-of-use assets 978 3,318 2,778

Amortization of long-term debt discount and issuance costs 985 1,086 1,321

Net realized gain on investments (5) — —

Loss on disposal of property and equipment — 806 726

Changes in operating assets and liabilities:

Receivable from contracts with collaborators (6,889) (5,338) —

Prepaid expenses and other current assets (8,453) 62 (3,892)

Accrued interest expense — (135) (97)

Cash flows from investing activities

Sales of marketable securities 7,144 — —

Purchase of property and equipment (79) — —

Cash flows from financing activities

Proceeds from the exercise of stock options 1,930 — —

Proceeds from the exercise of warrants 3,655 — —

Principal repayments of long-term debt — (12,581) (11,613)

Effect of exchange rate changes on cash and cash equivalents 141 (102) 110

Net increase (decrease) in cash and cash equivalents (8,342) 13,965 (79,864)

Cash and cash equivalents, at the end of the period $ 37,732 $ 46,074 $ 32,109

Supplemental disclosure of cash flow information:

Supplemental disclosure of noncash investing and financing activities:

Right-of-use assets obtained in exchange for lease liabilities $ — $ 5,298 $ —

Change in unrealized gain (loss) on marketable securities, net $ (90) $ 89 $ 191

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

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Gossamer Bio, Inc. Notes to Consolidated Financial Statements

Note 1—Description of Business

Gossamer Bio, Inc. (including its subsidiaries, referred to as "we," "us," "our,", or the “Company”) is a clinical-stage clinical biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of pulmonary hypertension ("PH") including pulmonary arterial hypertension ("PAH") and PH associated with interstitial lung disease ("PH-ILD"). The Company was incorporated in the state of Delaware on October 25, 2015 (originally as FSG Bio, Inc.) and is based in San Diego, California.

The consolidated financial statements include the accounts of Gossamer Bio, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions among the consolidated entity have been eliminated in consolidation.

Liquidity and Going Concern

The Company has incurred significant operating losses since its inception. As of December 31, 2025, the Company had an accumulated deficit of $1,438.9 million. From the Company’s inception through the year ended December 31, 2025, the Company has funded its operations primarily through equity financings, convertible senior notes and the Chiesi Collaboration Agreement (as defined in Note 12 below).

The consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and settlement of liabilities, in the normal course of business, and does not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or amounts and classification of liabilities that may result from the outcome of this uncertainty.

If the Company is not able to obtain the required funding, through equity or debt financings, license agreements for seralutinib in domestic or foreign markets, or other means, or is unable to obtain funding on terms favorable to the Company, or there is an event of default affecting the Company’s 2027 Notes, there will be a material adverse effect on commercialization and development operations, and the Company's ability to execute its strategic development plan for future growth. If the Company cannot successfully raise additional funding and implement its strategic development plan, the Company may be forced to make further reductions in spending, including spending in connection with our clinical development, pre-commercialization activities, extend payment terms with suppliers, suspend or curtail planned operations or cease operations entirely. The Company has concluded that these circumstances and the uncertainties associated with the Company’s ability to obtain additional equity or debt financing on terms that are favorable to the Company, or at all, and otherwise succeed in its future operations raise substantial doubt about the Company’s ability to continue as a going concern. Management believes that it has sufficient working capital on hand to fund operations into the first quarter of 2027.

Note 2—Summary of Significant Accounting Policies

Basis of Presentation

The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”).

Use of Estimates

The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The most significant estimates in the Company’s consolidated financial statements relate to accrued research and development expenses, stand-alone selling price of performance obligations and estimated collaboration expenses associated with the Company’s Chiesi Collaboration Agreement. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results could differ from those estimates.

Segments

Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker ("CODM") in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one operating segment. The

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identification of a single operating and reportable segment is consistent with the management approach as the CODM regularly reviews consolidated financial information for the purpose of assessing performance and allocating resources. See Note 13. Segment Reporting to the consolidated financial statements.

Cash and Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The carrying amounts reported in the consolidated balance sheets for cash and cash equivalents are valued at cost, which approximate their fair value.

Marketable Securities

The Company considers securities with original maturities of greater than three months to be marketable securities. The Company has the ability, if necessary, to liquidate any of its marketable securities to meet its liquidity needs in the next 12 months. Accordingly, those investments with contractual maturities greater than one year from the date of purchase are classified as current assets on the accompanying consolidated balance sheets which reflects management’s intention to use the proceeds from sales of these securities to fund our operations, as necessary. The Company’s marketable securities consist of U.S. Treasury and agency securities, commercial paper and corporate debt securities. Marketable securities are recorded at fair value and unrealized gains and losses are recorded within accumulated other comprehensive loss. The estimated fair value of the marketable securities is determined based on quoted market prices or rates for similar instruments. The Company evaluates securities with unrealized losses to determine whether such losses, if any, are due to credit-related factors. The Company records an allowance for credit losses when unrealized losses are due to credit-related factors. Realized gains and losses are calculated using the specific identification method and recorded in other income, net in the Company's consolidated statements of operation and comprehensive loss. The Company does not generally intend to sell the investments and it is not more likely than not that it will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity. The Company has determined that there were no material declines in fair values of its investments due to credit-related factors as of December 31, 2025.

Concentrations of Credit Risk and Off-Balance Sheet Risk

Cash, cash equivalents and marketable securities are financial instruments that are potentially subject to concentrations of credit risk. The Company’s cash and cash equivalents are deposited in accounts at large financial institutions, and amounts may exceed federally insured limits. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. The Company maintains its cash equivalents in U.S. Treasury and agency securities and commercial paper with maturities less than three months and in money market funds that invest in U.S. Treasury and agency securities.

The Company’s available for sale securities are also invested in U.S. Treasury and agency securities. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on its cash, cash equivalents and available for sale securities.

Property and Equipment, Net

Property and equipment, net, which consists mainly of lab equipment and leasehold improvements, are carried at cost less accumulated depreciation. Depreciation is computed over the estimated useful lives of the respective assets, generally two to seven years, using the straight-line method.

Convertible Senior Notes

The Company accounts for the 2027 Notes as a liability measured at amortized cost. The carrying amount was calculated by measuring the fair value of similar debt instruments that do not have associated convertible features. The excess of the principal amount over its carrying amount (“debt discount”) is amortized to interest expense over the term of the 2027 Notes. Issuance costs were recorded as a reduction to the principal amount of the 2027 Notes and are being amortized to interest expense over the term of the 2027 Notes.

Leases

In accordance with Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), the Company determines if an arrangement is a lease at inception. Operating leases are included in the balance sheet as right-of-use assets and operating lease liabilities at the present value of the lease payments calculated using the Company’s incremental borrowing rate, unless the implicit rate is readily available. The Company applied the short-term lease recognition exemption for leases with

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terms at inception not greater than 12 months and elected to not separate lease and non-lease components for its long-term leases. The Company records rent expense on a straight-line basis over the term of the lease.

Research and Development

All research and development costs are expensed as incurred. Research and development costs consist primarily of salaries, employee benefits, costs associated with preclinical studies and clinical trials (including amounts paid to clinical research organizations and other professional services). Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received.

The Company records accruals for estimated research and development costs, comprising payments for work performed by third party contractors, laboratories, participating clinical trial sites, and others. Some of these contractors bill monthly based on actual services performed, while others bill periodically based upon achieving certain contractual milestones. For the latter, the Company accrues the expenses as goods or services are used or rendered. Clinical trial site costs related to patient enrollment are accrued as patients enter and progress through the trial. Upfront costs, such as costs associated with setting up clinical trial sites for participation in the trials, are expensed immediately once incurred as research and development expenses.

In process research and development

In process research and development costs relate to a milestone payment to Pulmokine for the initiation of the Phase 3 clinical trial for seralutinib and acquisition of the Respira Merger Option.

Patent Costs

Costs related to filing and pursuing patent applications are expensed as incurred, as recoverability of such expenditures is uncertain. These costs are included in general and administrative expenses.

Income Taxes

Income taxes are recorded in accordance with Financial Accounting Standards Board (“FASB”) ASC 740, Income Taxes, which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company does not recognize any deferred taxes related to the U.S. taxes on foreign earnings as we recognize these taxes as a period cost.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company's policy is to include interest and penalties related to income taxes within its provision (benefit) for income taxes.

The Company is subject to taxation in the United States, California, Florida, Ireland and Luxembourg. As of December 31, 2025, the Company’s tax years since inception are subject to examination by taxing authorities due to the Company’s unutilized net operating losses ("NOLs") and tax credits.

Collaborative Arrangements

The Company assesses whether its licensing and other agreements are collaborative arrangements based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. For arrangements that the Company determines are collaborations, it identifies each unit of account, and then determines whether a customer relationship exists for that unit of account. If the Company determines a performance obligation within the collaborative arrangement to be with a customer, it applies its revenue recognition accounting policy. If a portion of a distinct bundle of goods or services within the collaborative arrangement is not with a customer, the Company applies recognition and measurement based on an analogy to authoritative accounting literature or, if there is no appropriate analogy, a reasonable, rational and consistently applied accounting policy election. To the extent the arrangement is within the scope of ASC 808, the Company assesses whether aspects of the arrangement between the Company

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and the collaboration partner are within the scope of other accounting literature. If the Company concludes that some or all aspects of the arrangement represent a transaction with a customer, the Company accounts for those aspects of the arrangement within the scope of ASC Topic 606, Revenue from Contracts with Customers (ASC 606). See Note 12, "Significant Agreements and Contracts," for more information.

Revenue Recognition

The Company recognizes revenue when a customer obtains control of promised goods or services in a contract for an amount that reflects the consideration the Company expects to receive in exchange for those goods or services. For contracts with customers, the Company performs 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) the Company satisfies each performance obligation. The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. As part of the accounting for contracts with customers, the Company develops assumptions that require judgment to determine the standalone selling price of each distinct performance obligation identified in the contract. In addition, variable consideration such as milestone payments are evaluated to determine if they are constrained and, therefore, excluded from the transaction price. The Company then allocates the total transaction price proportionally to each distinct performance obligation based on their estimated standalone selling prices, unless an allocation exception applies. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective distinct performance obligation when (or as) the performance obligation is satisfied.

In a contract with multiple performance obligations, the Company must develop estimates and assumptions that require judgment to determine the underlying standalone selling price for each distinct performance obligation, which determines how the transaction price is allocated among the distinct performance obligations. The estimation of the stand-alone selling price(s) may include estimates regarding forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. Any change made to estimated progress towards completion of a distinct performance obligation and, therefore, revenue recognized will be recorded as a change in estimate. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price.

If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in a contract, the Company recognizes revenues from the transaction price 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, the Company utilizes 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 revenue from the allocated transaction price. The Company evaluates the measure of progress at each reporting period and, if necessary, adjusts the measure of performance and related revenue or expense recognition as a change in estimate.

At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or a collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or a collaboration partner’s control, such as operational developmental milestones and any related constraint, and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which will affect revenue from sale of licenses and revenue from contracts with collaborators in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative revenue from sale of licenses and revenue from contracts with collaborators in the period of adjustment.

For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and a license is deemed to be the predominant item to which the royalties relate, the Company 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, the Company has not recognized any royalty revenue from collaborative arrangements.

For arrangements that include cost-share reimbursements, we will recognize such payments when control of the related goods or services are transferred to the customer. Cost-sharing reimbursements are presented as revenue from contracts with collaborators.

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Stock-Based Compensation

The Company expenses stock-based compensation to employees and non-employees over the requisite service period based on the estimated grant-date fair value of the awards. The Company records the expense for stock-based compensation awards subject to performance-based milestone vesting over the requisite service period when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions at each reporting date. The Company estimates the fair value of stock option grants and shares purchasable under the Company's 2019 Employee Stock Purchase Plan ("ESPP") using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. The Company estimates the fair value of restricted stock units based on the closing price of the Company's common stock on the date of grant. The Company accounts for forfeitures as they occur. All share-based compensation costs are recorded in the statements of operations based upon the underlying employees or non-employee’s roles within the Company.

Foreign Currency

Assets and liabilities of non-U.S. subsidiaries that operate in a local currency environment, where that local currency is the functional currency, are translated to U.S. dollars at exchange rates in effect at the balance sheet date. Income and expense accounts are translated at average exchange rates during the year which approximate the rates in effect at the transaction dates. The resulting translation adjustments are recorded in accumulated other comprehensive income (loss) in the Company's consolidated balance sheets. Foreign exchange transaction gains and losses are included in other income, net in the Company’s consolidated statement of operations and comprehensive loss.

Recent Accounting Pronouncements - Adopted

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280) Improvements to Reportable Segment Disclosures (“Topic 280”), which modifies the disclosure and presentation requirements of reportable segments. The amendments in the update require the disclosure of significant segment expenses that are regularly provided to the Chief Operating Decision Maker ("CODM") and included within each reported measure of segment profit and loss. The amendments also require disclosure of all other segment items by reportable segment and a description of its composition. Additionally, the amendments require disclosure of the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. Lastly, the amendment requires that a public entity that has a single reportable segment provide all the disclosures required by ASU 2023-07 and all existing segment disclosures in Topic 280. This update is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. We have adopted this standard for our fiscal year ended December 31, 2024. We have applied this standard retrospectively for all prior periods presented in the financial statements. There was no impact on our reportable segments identified and additional required disclosures have been included in Note 13, Segment Reporting.

In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topics 740): Improvements to Income Tax Disclosures, to expand the disclosure requirements for income taxes, specifically related to the rate reconciliation and income taxes paid. ASU 2023-09 is effective for our annual periods beginning January 1, 2025, with early adoption permitted. We have adopted this standard for our fiscal year ended December 31, 2025 on a retrospective basis, and the adoption did not have a material impact on our consolidated financial statements and related disclosures. See Note 7, Income Taxes, to the consolidated financial statements.

Recent Accounting Pronouncements - Not Yet Adopted

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, as further clarified by ASU 2025-01, Income Statement - Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date, issued in January, 2025, which requires disaggregated disclosure of certain costs and expenses on an interim and annual basis. ASU No. 2024-03 is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The disclosure updates are required to be applied prospectively with the option for retrospective application. The Company is currently evaluating the impact of adopting ASU No. 2024-03.

In December 2025, the FASB issued ASU No. 2025-12, Codification Improvements, to address suggestions received from stakeholders on the ASC and to make other incremental improvements to U.S. GAAP. The update represents

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changes to the ASC that clarify, correct errors in or make other improvements to a variety of topics that are intended to make it easier to understand and apply. ASU No. 2025-12 is effective for fiscal years beginning after December 15, 2026 and interim periods. The Company is currently evaluating the impact of adopting ASU No. 2024-12 on its consolidated financial statements and related disclosures.

In December 2025, the FASB issued ASU No. 2025-11, Interim Reporting (Topic 270), which provides clarifications intended to improve the consistency and usability of interim disclosure requirements, including a comprehensive listing of required interim disclosures and a new disclosure principle for reporting material events occurring after the most recent annual period. The amendments do not change the underlying objectives of interim reporting but are designed to enhance clarity in application. ASU No. 2025-11 is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal years. The Company is currently evaluating the impact of adopting ASU No. 2024-11 on its consolidated financial statements and related disclosures.

Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the SEC did not, or are not believed by management to, have a material impact on the Company’s present or future financial position, results of operations, cash flows or disclosures.

Net Loss Per Share

Basic net loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. The Company uses the if-converted method for assumed conversion of the 2027 Notes to compute the weighted average shares of common stock outstanding for diluted net loss per share. Diluted net loss per share excludes the potential impact of the Company’s common stock options, warrants for the purchase of common stock, unvested shares of restricted stock and the potential shares issuable upon conversion of the 2027 Notes because their effect would be anti-dilutive due to the Company’s net loss. Since the Company had a net loss in each of the periods presented, basic and diluted net loss per common share are the same because the otherwise dilutive potential common shares become anti-dilutive and are therefore excluded.

The table below provides potentially dilutive securities not included in the calculation of the diluted net loss per share because to do so would be anti-dilutive (in common stock equivalent shares):

December 31,

Shares issuable upon exercise of Chiesi Equity Option — 22,433,809 —

Nonvested shares under performance stock units 4,126,962 — —

Nonvested shares under restricted stock grants — — 427,698

Note 3—Accrued Expenses and Other Current Liabilities

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

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December 31,

Accrued compensation and benefits $ 11,211 $ 11,995

Operating lease liabilities 938 961

Accrued legal fees 84 65

Accrued accounting fees 449 180

Accrued income tax 6 —

Total accrued expenses and other current liabilities $ 15,827 $ 15,186

Note 4—Fair Value Measurements and Available for Sale Investments

Fair Value Measurements

The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1: Observable inputs such as quoted prices in active markets;

Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and

Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

The Company classifies its cash equivalents and available-for-sale investments within Level 1 or Level 2. The fair value of the Company’s investment grade corporate debt securities and commercial paper classified as Level 2 is determined using proprietary valuation models and analytical tools, which utilize market pricing or prices for similar instruments that are both objective and publicly available, such as matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, and offers.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents the hierarchy for assets measured at fair value on a recurring basis as of December 31, 2025 and 2024 (in thousands):

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Fair Value Measurements at End of Period Using:

U.S. Treasury and agency securities 8,090 8,090 — —

U.S. Treasury and agency securities 56,900 56,900 — —

The Company did not reclassify any investments between levels in the fair value hierarchy during the periods presented.

Fair Value of Other Financial Instruments

As of December 31, 2025 and 2024, the carrying amounts of the Company’s financial instruments, which include cash, prepaid and other current assets, interest receivable, accrued research and development expenses, accounts payable and accrued expenses and other current liabilities, approximate fair values because of their short-term maturities.

As of December 31, 2025 and 2024, the interest receivable was $0.3 million and $0.2 million, respectively. Interest receivable is recorded as a component of prepaid expenses and other current assets on the consolidated balance sheets.

As of December 31, 2025 and 2024 the fair value of the Company's 2027 Notes was $138.3 million and $110.0 million, respectively. The fair value was determined on the basis of market prices observable for similar instruments and is considered Level 2 in the fair value hierarchy (see Note 5).

Available for Sale Investments

The Company invests its excess cash in U.S. Treasury and agency securities, corporate debt securities, and commercial paper, which are classified as available-for-sale investments. These investments are carried at fair value and are included in the tables below. The Company evaluates securities with unrealized losses to determine whether such losses, if any, are due to credit-related factors. Realized gains and losses are calculated using the specific identification method and recorded in other income, net in the Company's consolidated statements of operations and comprehensive loss. The Company has classified these investments as available-for-sale, as the sale of such investments may be required prior to maturity to implement management strategies, and therefore has classified all investment securities as current assets.

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The aggregate market value, cost basis, and gross unrealized gains and losses of available-for-sale investments by security type, classified in marketable securities as of December 31, 2025 and 2024 are as follows (in thousands except securities amounts):

AmortizedCost GrossUnrealizedGains GrossUnrealizedLosses TotalFair Value

U.S Treasury and agency securities $ 8,088 $ 2 $ — $ 8,090

Number of securities with unrealized losses 1

U.S. Treasury and agency securities $ 56,875 $ 25 $ — $ 56,900

Number of securities with unrealized losses 5

As of December 31, 2025 and 2024, the Company classified $22.2 million and $25.3 million, respectively, of assets with original maturities of three months or less as cash and cash equivalents.

At each reporting date, the Company performs an evaluation of impairment to determine if any unrealized losses are due to credit-related factors. The Company records an allowance for credit losses when unrealized losses are due to credit-related factors. Factors considered when evaluating available-for-sale investments for impairment include the severity of the impairment, changes in underlying credit ratings, the financial condition of the issuer, the probability that the scheduled cash payments will continue to be made and the Company’s intent and ability to hold the investment until recovery of the amortized cost basis. The Company does not intend to sell these debt securities that are in an unrealized loss position, and it is not more likely than not that the Company will be required to sell these debt securities before recovery of their amortized cost bases, which may be at maturity. Based on the credit quality of the debt securities, and the Company’s estimates of future cash flows to be collected from those securities, the Company believes the unrealized losses are not credit losses. As of December 31, 2025 and 2024, there were no material declines in the market value of the Company's available-for-sale investments due to credit-related factors.

Contractual maturities of available-for-sale debt securities, as of December 31, 2025, were as follows (in thousands):

EstimatedFair Value

Greater than one year —

The Company has the ability, if necessary, to liquidate any of its cash equivalents and marketable securities to meet its liquidity needs in the next 12 months.

Note 5—Indebtedness

Credit Facility

On May 2, 2019, the Company entered into a credit, guaranty and security agreement, as amended on September 18, 2019, July 2, 2020, December 7, 2022 and February 14, 2023 (the “Credit Facility”), with MidCap Financial Trust (“MidCap”), as agent and lender, and the additional lenders party thereto from time to time (together with MidCap, the “Lenders”), pursuant to which the Lenders, agreed to make term loans available to the Company for working capital and general business purposes, in a principal amount of up to $150.0 million in term loan commitments, including a $30.0 million term loan that was funded at the closing date, with the ability to access the remaining $120.0 million in two additional tranches

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(each $60.0 million), subject to specified availability periods, the achievement of certain clinical development milestones, minimum cash requirements and other customary conditions. On May 3, 2024, the Credit Facility was terminated and the Company recorded a $7.7 million payment of the outstanding debt balance in full and discharged, which released the Company from the obligations under the Credit Facility, and Lenders’ security interests in the Company’s assets and property were released. Unamortized debt discount and issuance costs were written off and recorded in interest expense on the consolidated statements of operations and comprehensive loss. As of December 31, 2025, the Company has no further obligations under the Credit Facility.

5.00% Convertible Senior Notes due 2027

On May 21, 2020, the Company issued $200.0 million aggregate principal amount of 5.00% convertible senior notes due 2027 in a public offering (the "2027 Notes"). The 2027 Notes were registered pursuant to the Company’s shelf registration statement on Form S-3 filed with the SEC on April 10, 2020. The interest rate on the 2027 Notes is fixed at 5.00% per annum. Interest is payable semi-annually in arrears on June 1 and December 1 of each year, commencing on December 1, 2020. The 2027 Notes will mature on June 1, 2027. The net proceeds from the offering, after deducting the underwriting discounts and commissions and other offering costs, were approximately $193.6 million. The 2027 Notes may be settled in cash, shares of the Company’s common stock, or a combination thereof, solely at the Company’s election. The initial conversion rate of the 2027 Notes is 61.6095 shares per $1,000 principal amount, which is equivalent to a conversion price of approximately $16.23 per share, subject to adjustments. In addition, following certain corporate events that occur prior to the maturity date or if the Company issues a notice of redemption, the Company will increase the conversion rate for a holder who elects to convert its 2027 Notes in connection with such a corporate event during the related redemption period in certain circumstances.

The 2027 Notes are senior unsecured obligations of the Company, ranking senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the 2027 Notes, and are effectively subordinated to the Company’s existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness.

Holders may convert their notes at their option only in the following circumstances: (1) during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on September 30, 2020, if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price for each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; (2) during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) in which the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions on the Company’s common stock; (4) if the Company calls such notes for redemption; and (5) at any time from, and including, March 1, 2027 until the close of business on the scheduled trading day immediately before the maturity date.

The Company did not have the right to redeem the 2027 Notes prior to June 6, 2024. As of December 31, 2025, the Company has not redeemed the 2027 Notes. On or after June 6, 2024 and on or before the 50th scheduled trading day immediately before the maturity date, the Company may redeem the 2027 Notes, in whole or in part, if the last reported sale price of the Company’s common stock has been at least 130% of the conversion price then in effect on (1) each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice; and (2) the trading day immediately before the date the Company sends such notice. In the case of any optional redemption, the Company will redeem the 2027 Notes at a redemption price equal to 100% of the principal amount of such Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.

If the Company undergoes a fundamental change prior to the maturity date of the 2027 Notes, holders of the 2027 Notes may require the Company to repurchase for cash all or part of their 2027 Notes at a repurchase price equal to 100% of the principal amount of the 2027 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

The indenture governing the 2027 Notes provides for customary terms and covenants, including that upon certain events of default, either the trustee or the holders of not less than 25% in aggregate principal amount of the 2027 Notes then outstanding may declare the unpaid principal amount of the 2027 Notes and accrued and unpaid interest, if any, thereon immediately due and payable. As of December 31, 2025, the Company was in compliance with these covenants. In the case of

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certain events of bankruptcy, insolvency or reorganization, the principal amount of the 2027 Notes together with accrued and unpaid interest, if any, thereon will automatically become and be immediately due and payable.

As of December 31, 2025 and 2024, there were no events or market conditions that would allow holders to convert the 2027 Notes. When the 2027 Notes become convertible within 12 months of the balance sheet date, the carrying value of the 2027 Notes will be reclassified to short-term.

The Company accounts for the 2027 Notes as a single liability measured at amortized cost. As the equity component is no longer required to be split into a separate component, the Company recorded an adjustment to reflect this update.

The Company recorded $0.4 million of the debt issuance costs related to the 2027 Notes as a reduction to the liability and amortizes these costs to interest expense over the term of the 2027 Notes.

The net carrying amount of the 2027 Notes was as follows (in thousands):

December 31,

Unamortized debt discount (1,398) (2,321)

Unamortized debt issuance cost (94) (156)

The following table sets forth the interest expense recognized related to the 2027 Notes (in thousands):

Year Ended December 31,

Amortization of debt issuance cost 62 59 56

Note 6—Licenses, Asset Acquisitions and Contingent Consideration

The following purchased assets were accounted for as asset acquisitions as substantially all of the fair value of the assets acquired were concentrated in a group of similar assets and/or the acquired assets were not capable of producing outputs due to the lack of employees and early stage of development. Because the assets had not yet received regulatory approval, the fair value attributable to these assets was recorded as in process research and development (“IPR&D”) expenses in the Company’s consolidated statements of operations and comprehensive loss for the years ended December 31, 2025, 2024, and 2023.

The Company accounts for contingent consideration payable upon achievement of certain regulatory, development or sales milestones in such asset acquisitions when the underlying contingency is met.

License from Pulmokine, Inc. (Seralutinib)

On October 2, 2017, the Company entered into a license agreement with Pulmokine, Inc. under which it was granted an exclusive worldwide license and sublicense to certain intellectual property rights owned or controlled by Pulmokine to develop and commercialize seralutinib and certain backup compounds for the treatment, prevention and diagnosis of any and all disease or conditions. On November 26, 2024, Pulmokine became a wholly-owned subsidiary of XOMA Royalty Corporation. The Company also has the right to sublicense its rights under the license agreement, subject to certain conditions. The assets acquired are in the early stages of the FDA approval process, and the Company intends to further develop the assets acquired through potential FDA approval as evidenced by the milestone arrangement in the contract. The development activities cannot be performed without significant cost and effort by the Company. The agreement will remain in effect from the effective date, unless terminated earlier, until, on a licensed product-by-licensed product and country-by-country basis, the later of ten

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years from the date of first commercial sale or when there is no longer a valid patent claim covering such licensed product or specified regulatory exclusivity for the licensed product in such country. The Company is obligated to make future development and regulatory milestone payments of up to $48.0 million, which includes a payment of $5.0 million due upon initiation of a Phase 3 clinical trial in a second indication, commercial milestone payments of up to $45.0 million, and sales milestone payments of up to $190.0 million. The Company is also obligated to pay tiered royalties on sales for each licensed product, at percentages ranging from the mid-single digits to the high single-digits. In addition, if the Company chooses to sublicense or assign to any third parties its rights under the agreement with respect to a licensed product, or the Company’s seralutinib operating subsidiary undergoes a change of control, the Company must pay to Pulmokine a specified percentage of all revenue to be received in connection with such transaction. The Company made an upfront payment of $5.5 million in October 2017. The Company made a milestone payment of $5.0 million in connection with the initiation of the first Phase 2 clinical trial of seralutinib in January 2021 and made a milestone payment of $10.0 million, which was accrued in 2023, in connection with the initiation of the Phase 3 clinical trial of seralutinib in January 2024. The Company recognized these milestone payments as research and development expense on its consolidated statements of operations and comprehensive loss. As of December 31, 2025, no other milestones had been accrued as the underlying contingencies had not yet been met.

The Company recorded the following IPR&D expense on the consolidated statements of operations and comprehensive loss (in thousands):

Year Ended December 31,

Seralutinib $ — $ — $ 10,000

Note 7—Income Taxes

The amount of net loss before taxes for the years ended December 31, 2025, 2024, and 2023 is as follows:

December 31,

(in thousands)

A reconciliation of income tax expense (benefit) for the years ended December 31, 2025, 2024 and 2023 is as follows:

December 31,

(in thousands)

Current:

Total income tax expense (benefit) $ (88) $ 893 $ 8

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets and liabilities at December 31, 2025, 2024 and 2023 are shown below. The Company has established a valuation allowance against net deferred tax assets due to the uncertainty that such assets will be realized. The Company periodically evaluates the recoverability of the deferred assets. At such time as it is determined that it is more likely than not that the deferred tax asset will be realized, the valuation allowance will be reduced. The change in the valuation allowance for the year ended December 31, 2025 was an increase of $45.0 million.

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For the Year Ended December 31,

(in thousands)

Deferred tax assets:

Deferred tax liabilities:

Other (13) (3) —

Property, plant and equipment — — (108)

Total gross deferred tax liabilities (894) (1,086) (768)

Net deferred tax asset $ — $ — $ —

As of December 31, 2025, the Company had federal and state NOL carryforwards of approximately $540.6 million and $10.2 million, respectively. The majority of the federal NOL carryforwards can be carried forward indefinitely and be available to offset up to 80% of future taxable income each year. The state NOL carryforwards begin to expire in 2036. As of December 31, 2025, the Company also has Irish NOL carryforwards of approximately $143.3 million, which can be carried forward indefinitely.

As of December 31, 2025, the Company also had orphan drug credit and federal research tax credit carryforwards of approximately $65.8 million and California research tax credits of $12.0 million. The federal research tax credit carryforwards begin to expire in 2038, and the California research tax credit carryforward does not expire and can be carried forward indefinitely until utilized.

Upon adoption of ASU 2023-09, the differences between income taxes expected at the U.S. federal statutory income tax rate of 21% and the reported income tax (benefit) expense are summarized as follows:

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(in thousands)

Federal statutory income tax rate $ (35,795) 21.0 %

State income taxes, net of federal benefit (1) 5 — %

Foreign Tax Effects

Ireland

Statutory tax rate difference between Ireland and United States 4,245 (2.5 %)

Change in valuation allowance 1,916 (1.1 %)

Other Adjustments 644 (0.4 %)

Tax Credits

Research and development credit, net (1,386) 0.8 %

Orphan Drug Credit, net (14,230) 8.3 %

Change in valuation allowance 41,203 (24.2 %)

Nontaxable or nondeductible items

Non-Deductible Interest 2,307 (1.4 %)

Other Adjustments (274) 0.2 %

Effective Tax Rate $ (88) — %

(1) Income taxes in California made up the majority (greater than 50 percent) of the tax effect in this category.

The reconciliation of the federal statutory income tax rate to the Company's effective income tax rate in accordance with the guidance prior to the adoption of ASU 2023-09 was as follows:

Year Ended December 31,

Reconciliation to U.S. Statutory Rate 2024 2023

Federal statutory income tax rate 21.00 % 21.00 %

Change in valuation allowance (12.38 %) (8.73 %)

Research and experimentation credits 3.03 % 5.69 %

Foreign rate differential (3.75 %) (2.13 %)

GILTI (4.72 %) — %

Stock-based compensation (4.61 %) (1.44 %)

Nondeductible interest (4.13 %) (1.27 %)

Domestic/Foreign Restructuring Impact 2.52 % (12.49 %)

Effective Tax Rate (1.60 %) 0.01 %

The NOL carryforward may be subject to an annual limitation under Section 382 and 383 of the Internal Revenue Code of 1986, and similar state provisions if the Company experienced one or more ownership changes which would limit the amount of NOL and tax credit carryforwards that can be utilized to offset future taxable income and tax respectively. In general, an ownership change as defined by Sections 382 and 383, results from the transactions increasing ownership of certain stockholders or public groups in the stock of the corporation of more than 50 percentage points over a three-year period. The Company had an ownership change with the IPO in February of 2019 which resulted in no forfeiture of NOLs or credits. The Company had an additional ownership change in July of 2023, which resulted in a significant limitation on the Company's utilization of its NOLs and is expected to result in forfeiture of some federal net operating losses and all of the pre-change federal credits. Due to the existence of the valuation allowance, limitations created by future ownership changes, if any, will not impact the Company’s effective tax rate.

The Company files income tax returns in the United States, California, Florida and Ireland. Due to the Company’s losses incurred, the Company is subject to the income tax examination by authorities since inception. The Company’s policy is to recognize interest expense and penalties related to income tax matters as tax expense. For the years ended December 31, 2025, 2024 and 2023 and as of December 31, 2025 and 2024, there were no accruals for interest related to unrecognized tax benefits or tax penalties.

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A reconciliation of the beginning and ending amount of unrecognized tax benefits for 2025, 2024, and 2023, excluding interest and penalties, is as follows:

December 31,

(in thousands)

Decrease related to prior year positions (1,359) (2,028) —

Included in the balance of unrecognized tax benefits at December 31, 2025 is $15.5 million that, if recognized, would not impact the Company’s income tax benefit or effective tax rate as long as the Company's deferred tax asset remains subject to a full valuation allowance.

The company did not make any material income tax payments for federal, state or foreign purposes.

Note 8—Stockholders’ Equity (Deficit)

Common Stock

Each share of common stock is entitled to one vote. Common stock owners are entitled to dividends when funds are legally available and declared by the Company's board of directors.

Private Placement Financing

On July 24, 2023, the Company completed a private placement of 129,869,440 shares of the Company’s common stock and accompanying warrants to purchase up to 32,467,360 shares of the Company's common stock at a combined purchase price of $1.63125 per share and accompanying warrant, or with respect to any purchaser that was an officer, director, employee or consultant of the Company $1.85125, per share and accompanying warrant. Each warrant has an exercise price per share of $2.04, was immediately exercisable on the date of issuance and will expire five years from the closing of the private placement. The aggregate gross proceeds for the private placement were $212.1 million, before deducting offering expenses, which equaled $10.8 million. On August 18, 2023, the Company filed a registration statement on Form S-3 registering the shares of common stock and shares of common stock issuable upon the exercise of warrants issued in the private placement, which registration statement was declared effective on August 28, 2023.

Shares of Common Stock Subject to Repurchase

On December 3, 2015, the Company issued 9,160,888 shares of common stock as founder shares for services rendered to the Company, valued at $0.0001 par value per share, for a total of approximately $4,100 (the “founder shares”). On January 4, 2018, incremental vesting conditions were placed on the previously issued founder shares. Fifty percent of the previously issued founder shares vested on January 4, 2018, and the remaining founder shares are subject to vesting restrictions over a period of five years. These shares are subject to repurchase by the Company upon a founder's termination of employment or service to the Company.

Pursuant to the employment agreements with the Company’s founders executed January 4, 2018, the Company provided for certain potential additional issuances of common stock (the “anti-dilution shares”) to each of the founders to ensure the total number of shares of common stock held by them and their affiliates (inclusive of any shares subject to equity awards granted by the Company) would represent 15% of the Company’s fully-diluted capitalization until such time as the Company raised $300.0 million in equity capital, including the capital raised in the Series A financing.

In furtherance of this obligation, on May 21, 2018, the Company issued 251,547 shares of common stock to the founders for services rendered to the Company, valued at $2.61 per share with an additional 251,547 shares of restricted stock subject to the same vesting restrictions and vesting period as the founder shares. In addition, on September 6, 2018, the Company issued 1,795,023 shares of common stock to the founders for services rendered to the Company, valued at $9.63 per share, with an additional 1,795,023 shares of restricted stock subject to the same vesting restrictions and vesting period as the founder shares.

Any shares subject to repurchase by the Company are not deemed, for accounting purposes, to be outstanding until those shares vest. As such, the Company recognizes the measurement date fair value of the restricted stock over the

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vesting period as compensation expense. As of December 31, 2025, there were no shares of common stock subject to repurchase by the Company. The unvested stock liability related to these awards is immaterial to all periods presented.

Chiesi Equity Option

On May 3, 2024, pursuant to the Chiesi Collaboration Agreement (as defined in Note 12 below) the Company granted to Chiesi (as defined in Note 12 below) an option to purchase directly from the Company, on one or more occasions, up to an aggregate number of shares of the Company’s common stock (the "Equity Option") such that immediately following such issuance, Chiesi’s beneficial ownership of the Company’s common stock shall not exceed 9.9% of the total number of issued and outstanding shares of the Company’s common stock. The Equity Option shall be exercisable by Chiesi, in whole or in part, at any time prior to the earliest to occur of the date on which (a) the last patient is last dosed in either (i) the PROSERA Phase 3 study for PAH or (ii) a Phase 3 clinical trial for the PH-ILD Indication, (b) any third party commences a tender offer or exchange offer for more than 50% of the outstanding shares of the Company’s common stock, and (c) the Company publicly announces its intent to consummate a GB002, Inc. change of control. The purchase price of each share the Company’s common stock subject to the Equity Option shall be equal to 107.5% of the daily volume-weighted average per share price of the Company’s common stock on The Nasdaq Stock Market over the 30-trading day period ending on and including the last trading day prior to the date on which Chiesi delivers an exercise notice to the Company; provided that such purchase price shall be no less than $1.63 per share. The shares of the Company’s common stock to be issued will be issued in a private placement in reliance on Section 4(a)(2) of the Securities Act of 1933, as amended, for transactions by an issuer not involving any public offering, pursuant to the terms of a stock issuance agreement to be entered into between the Company and Chiesi in connection with each such exercise of the Equity Option. The Company evaluated the Equity Option granted to Chiesi as consideration payable to a customer and determined it qualified under ASC 718. Due to the market condition included in the Equity Option, the Company used the Geometric Brownian Motion/Monte Carlo model to determine fair market value. The value of the Equity Option is $0.5 million, which is included in additional paid-in capital on the Company's consolidated balance sheets. In November 2025, the Equity Option expired and is no longer exercisable.

Note 9—Equity Incentive Plans

2023 Equity Inducement Incentive Plan

In November 2023, the Company approved the 2023 Employment Inducement Incentive Plan (the "2023 Inducement Plan"). The terms of the 2023 Inducement Plan are substantially similar to the terms of the Company’s 2019 Incentive Award Plan (as described below) with the exception that incentive stock options may not be issued under the 2023 Inducement Plan and awards under the 2023 Inducement Plan may only be issued to eligible recipients under the applicable Nasdaq rules. The 2023 Inducement Plan was adopted without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. In accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules, awards under the 2023 Inducement Plan may only be made to an employee who has not previously been an employee or member of the board of directors of the Company or any parent or subsidiary, or following a bona fide period of non-employment by the Company or a parent or subsidiary, if he or she is granted such award in connection with his or her commencement of employment with the Company or a subsidiary and such grant is an inducement material to his or her entering into employment with the Company or such subsidiary. The Company has initially reserved 6,762,279 shares of the Company’s common stock for issuance pursuant to awards granted under the 2023 Inducement Plan. As of December 31, 2025, an aggregate of 1,856,658 shares of common stock were available for issuance under the 2023 Inducement Plan, and 4,811,455 shares of common stock were subject to outstanding awards under the 2023 Inducement Plan.

2019 Equity Incentive Plan

In January 2019, the Company’s board of directors and stockholders approved and adopted the 2019 Incentive Award Plan (the “2019 Plan”). The 2019 Plan became effective on February 6, 2019, the day prior to the effectiveness of the registration statement filed in connection with the IPO. Under the 2019 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock or cash-based awards to individuals who are then employees, officers, directors or consultants of the Company, and employees and consultants of the Company’s subsidiaries. A total of 5,750,000 shares of common stock were approved to be initially reserved for issuance under the 2019 Plan. The number of shares that remained available for issuance under the 2017 Plan (as defined below) as of the effective date of the 2019 Plan were, and shares subject to outstanding awards under the 2017 Plan as of the effective date of the 2019 Plan that are subsequently canceled, forfeited or repurchased by the Company will be added to the shares reserved under the 2019 Plan. The Company’s board of directors and stockholders approved an amendment and restatement to the 2019 Plan in 2025 to, among other things, increase the aggregate number of shares of common stock authorized for issuance under the 2019 Plan by 11,350,000 shares of common stock. In addition, the number of shares of common stock available for issuance under the 2019 Plan will be automatically increased on the first day of each calendar year during the ten-year term of the 2019 Plan, beginning

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with January 1, 2026 and ending with January 1, 2035, by an amount equal to 5% of the outstanding number of shares of the Company’s common stock on December 31 of the preceding calendar year or such lesser amount as determined by the Company’s board of directors. As of December 31, 2025, an aggregate of 8,445,734 shares of common stock were available for issuance under the 2019 Plan and 44,796,989 shares of common stock were subject to outstanding awards under the 2019 Plan.

2019 Employee Stock Purchase Plan

In January 2019, the Company’s board of directors and stockholders approved and adopted the 2019 Employee Stock Purchase Plan (the "ESPP"). The ESPP became effective as of February 6, 2019, the day prior to the effectiveness of the registration statement filed in connection with the IPO. The ESPP permits participants to purchase common stock through payroll deductions of up to 20% of their eligible compensation. A total of 700,000 shares of common stock were approved to be initially reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be automatically increased on the first day of each calendar year during the first ten years of the term of the ESPP, beginning with January 1, 2020 and ending with January 1, 2029, by an amount equal to 1% of the outstanding number of shares of the Company’s common stock on December 31 of the preceding calendar year or such lesser amount as determined by the Company’s board of directors. During the years ended December 31, 2025 and 2024, 1,089,883 shares and 767,125 shares were issued pursuant to the ESPP, respectively. As of December 31, 2025, an aggregate of 5,721,970 shares of common stock were available for issuance under the ESPP.

2017 Equity Incentive Plan

The Company’s 2017 Equity Incentive Plan (the “2017 Plan”) permitted the granting of incentive stock options, non-statutory stock options, restricted stock, restricted stock units and other stock-based awards. Subsequent to the adoption of the 2019 Plan, no additional equity awards can be made under the 2017 Plan. As of December 31, 2025, 1,955,471 shares of common stock were subject to outstanding options under the 2017 Plan, and no shares of restricted stock awards granted under the 2017 Plan were unvested.

Stock Options

The fair value of each employee and non-employee time-vested stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company uses its own volatility to the extent it has sufficient trading history, and for awards in which sufficient trading history is not available, a peer group is used to calculate the expected volatility. Due to the lack of historical exercise history, the expected term of the Company’s stock options for employees has been determined utilizing the “simplified” method for awards. The expected term of stock options granted to non-employees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is zero based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

On May 5, 2023, the Company granted to its Chairman and Chief Executive Officer 750,000 options with an exercise price of $1.36 per share. This grant contains both service and market based vesting conditions. The awards vest on the later of the date of achievement and the one-year anniversary of the grant date. The market condition becomes satisfied in 50%, 25% and 25% tranches upon achieving the average per-share closing price of the Company's common stock over any 30 consecutive calendar days following the grant date equal to or exceeding $5.00, $7.50 and $10.00, respectively. In the event a stock price tranche has not vested prior to the fourth anniversary of the grant date, any portion of the option attributable to such tranche will be forfeited. Due to the market condition included in this grant, the Company used the Geometric Brownian Motion/Monte Carlo model to value this award. The total stock-based compensation expense related to this award is $0.4 million, which is included in general and administrative expense on the consolidated statements of operations and comprehensive loss. The Company expects to recognize this expense over a weighted average period of approximately 2.2 years.

Effective May 5, 2023, and in accordance with the terms of the 2019 Plan, the Company's board of directors approved a stock option repricing (the “Option Repricing”) whereby the exercise price of each Eligible Option (as defined below) was immediately reduced to $1.36 per share, the closing stock price on May 5, 2023. For purposes of the Option Repricing, “Eligible Options” are 6,817,057 outstanding stock options as of May 5, 2023 (vested or unvested) granted under the 2019 Plan prior to November 30, 2022 and held by those eligible employees of the Company identified by the Company's board of directors, including the Company’s executive officers, except for the Company’s Chairman and Chief Executive Officer.

The participation of the executive officers of the Company in the Option Repricing was subject to their agreement to cancel a portion of their Eligible Options effective immediately (the “Cancelled Options”). Each executive was

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required to agree to cancel one-third of his or her Eligible Options, on a grant-by-grant basis. The Cancelled Options were deducted proportionately from the vested and unvested portions of each Repriced Option grant.

To the extent an Eligible Option is exercised prior to the Premium End Date (as defined below), or the eligible employee’s employment terminates prior to the Premium End Date, the eligible employee will be required to pay the original exercise price per share of the Eligible Options in connection with any exercise of the Eligible Option. The “Premium End Date” means the earliest of (i) May 5, 2024, (ii) the date of a change in control, (iii) the eligible employee’s death or disability, or (iv) if an eligible employee is an executive subject to the cancellation of a portion of Eligible Options and is terminated under circumstances giving rise to severance under his or her employment agreement, the date of such termination. Except for the reduction in the exercise prices of the Eligible Options as described above, the Eligible Options will retain their existing terms and conditions as set forth in the 2019 Plan and the applicable award agreements.