ALUMIS INC.

Previous wording

You should read the following discussion and analysis of our financial condition and results of operations in conjunction with our consolidated financial statements and the related notes and other financial information included elsewhere in this Annual Report on Form 10-K. This discussion and analysis and other parts of this Annual Report on Form 10-K contain forward-looking statements based upon current beliefs, plans and expectations related to future events and our future financial performance that involve risks, uncertainties and assumptions, such as statements regarding our intentions, plans, objectives and expectations for our business. Our actual results and the timing of selected events could differ materially from those described or implied by these forward-looking statements as a result of several factors, including those set forth under Part I, Item 1A. “Risk Factors” in this Annual Report on Form 10-K. See also see the section titled “Special Note Regarding Forward-Looking Statements.”

Current wording

You should read the following discussion and analysis of our financial condition and results of operations in conjunction with our consolidated financial statements and the related notes and other financial information included elsewhere in this Annual Report on Form 10-K. This discussion and analysis and other parts of this Annual Report on Form 10-K contain forward-looking statements based upon current beliefs, plans and expectations related to future events and our future financial performance that involve risks, uncertainties and assumptions, such as statements regarding our intentions, plans, objectives and expectations for our business. Our actual results and the timing of selected events could differ materially from those described in or implied by these forward-looking statements as a result of several factors, including those set forth under Part I, Item 1A. “Risk Factors” in this Annual Report on Form 10-K. See also the section titled “Special Note Regarding Forward-Looking Statements.”

Previous wording

We are a clinical stage biopharmaceutical company with an initial focus on developing our two TYK2 inhibitors: ESK-001, a second-generation inhibitor that we are developing to maximize target inhibition and optimize tolerability, and A-005, a CNS penetrant molecule. ESK-001 has demonstrated significant therapeutic effect in our Phase 2 program in patients with PsO, and is currently being evaluated in an additional Phase 2 clinical trial in patients with SLE, for which we expect to report results in 2026. With the favorable results in our Phase 2 clinical trial in PsO, we have initiated our Phase 3 ONWARD clinical program, which consists of two parallel Phase 3 clinical trials of ESK-001 in this indication and for which we expect to report topline results in the first quarter of 2026. These parallel Phase 3 clinical trials also include one LTE study, ONWARD3. In addition, the OLE of our Phase 2 clinical trial in PsO remains ongoing. TYK2 genetic mutations are associated with a strong protective effect in MS, motivating us to develop our second product candidate, A-005, as a CNS-penetrant, allosteric TYK2 inhibitor for neuroinflammatory and neurodegenerative diseases. In April 2024, we initiated our Phase 1 program of A-005 in healthy volunteers and reported initial results in December 2024.

Current wording

We are a clinical stage biopharmaceutical company with an initial focus on developing our two TYK2 inhibitors: envu, formerly known as ESK-001, a second-generation inhibitor that we are developing to maximize target inhibition and optimize tolerability, and A-005, a CNS penetrant molecule. Envu is currently being evaluated in an ongoing Phase 2 OLE trial, as well as a Phase 3 LTE trial in patients with PsO and we plan to submit an NDA for envu in PsO to the FDA in the second half of 2026. Envu completed enrollment in the pivotal Phase 3 ONWARD1 and ONWARD2 clinical trials in patients with PsO, and we reported positive topline results in the first quarter of 2026. In addition, envu is currently being evaluated in a Phase 2 clinical trial in patients with SLE, for which we expect to report topline results in the third quarter of 2026. We are currently evaluating additional immune-mediated disease indications for envu, beyond PsO and SLE, and for A-005 in CNS and peripheral diseases. In April 2024, we initiated our Phase 1 program of A-005 in healthy volunteers and reported initial results in December 2024. In addition, in connection with the ACELYRIN Merger, we acquired lonigutamab, a subcutaneously delivered, monoclonal antibody targeting IGF-1R for the potential treatment of TED. We are continuing to evaluate the development program for lonigutamab and its potential differentiation in a capital efficient manner.

Previous wording

Since our inception, we have devoted substantially all of our efforts to organizing our company, hiring personnel, business planning, acquiring and developing our product candidates, performing research and development, conducting preclinical studies and clinical trials, establishing and protecting our intellectual property portfolio, raising capital and providing general and administrative support for these activities. We do not have any products approved for sale and have not generated any revenue from product sales. We expect to continue to incur significant and increasing expenses and increasing substantial losses for the foreseeable future as we continue our development of and seek regulatory approvals for our product candidates and commercialize any approved products, seek to expand our product pipeline and invest in our organization. Our ability to achieve and sustain profitability will depend on our ability to successfully develop, obtain regulatory approval for and commercialize our product candidates. There can be no assurance that we will ever earn revenue or achieve profitability, or if achieved, that the revenue or profitability will be sustained on a continuing basis.

Current wording

Since our inception, we have devoted substantially all of our efforts to organizing our company, hiring personnel, business planning, acquiring and developing our product candidates, performing research and development, conducting preclinical studies and clinical trials, establishing and protecting our intellectual property portfolio, raising capital, integrating the acquired ACELYRIN business and personnel, and providing general and administrative support for these activities. We do not have any products approved for sale and have not generated any revenue from product sales. We expect to continue to incur significant and increasing expenses and increasing substantial losses for the foreseeable future as we continue our development of and seek regulatory approvals for our product candidates and commercialize any approved products, seek to expand our product pipeline and invest in our expanded organization following the ACELYRIN Merger. Our ability to achieve and sustain profitability will depend on our ability to successfully develop, obtain regulatory approval for and commercialize our product candidates. There can be no assurance that we will ever achieve profitability, or if achieved, that the revenue or profitability will be sustained on a continuing basis.

Previous wording

To date, we have primarily funded our operations with proceeds from sales of shares of our common stock and redeemable convertible preferred stock and the issuance of convertible promissory notes in private placements. In July 2024, we closed our IPO and the Concurrent Private Placement and received $233.3 million in net proceeds, after deducting underwriting discounts and commissions and offering expenses payable by the Company. As of December 31, 2024, we had $288.3 million in cash, cash equivalents and marketable securities.

Current wording

As of December 31, 2025, we had $308.5 million in cash, cash equivalents and marketable securities.

Previous wording

with our research and development efforts, including acquisitions of in-process research and development assets, and, to a lesser extent, from general and administrative costs associated with our operations. Our net losses and operating losses may fluctuate from quarter to quarter and year to year depending primarily on the timing of acquisition of any new product candidates, the timing of our preclinical studies and clinical trials, our other research and development expenses, and the timing and amount of any milestone or royalty payments due under our existing or future license agreements. In addition, we have incurred and will continue to incur additional costs associated with operating as a public company, including significant legal, audit, accounting, regulatory and tax-related services associated with maintaining compliance with exchange listing and SEC requirements, director and officer liability insurance costs, investor and public relations costs, and other expenses that we did not incur as a private company.

Current wording

We have incurred significant operating losses and negative cash flows since our inception. Our net loss for the years ended December 31, 2025 and 2024 was $243.3 million and $294.2 million, respectively. As of December 31, 2025, we had an accumulated deficit of $901.9 million. Substantially all of our net losses have resulted from costs incurred in connection with our research and development efforts, including acquisitions of in-process research and development assets, and, to a lesser extent, from general and administrative costs associated with our operations. Our net losses and operating losses may fluctuate from quarter to quarter and year to year depending primarily on the timing of acquisition of any new product candidates, the timing of our preclinical studies and clinical trials, our other research and development expenses, and the timing and amount of any milestone or royalty payments due under our existing or future license agreements. We have incurred and will continue to incur costs associated with operating as a public company, including significant legal, audit, accounting, regulatory and tax-related services associated with maintaining compliance with exchange listing and SEC requirements, director and officer liability insurance costs, investor and public relations costs, and other expenses.

Previous wording

We do not have any products approved for sale and have not generated any revenue from product sales since our inception. We do not expect to generate revenue from any product candidates that we develop until we obtain regulatory approval for one or more of such product candidates and commercialize our products or enter into collaboration agreements with third parties. Because of the numerous risks and uncertainties associated with biopharmaceutical product development, we may never achieve or sustain profitability and, unless and until we are able to develop and commercialize our product candidates, we will need to continue to raise additional capital. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through public or private equity or debt financings, or potentially other capital sources, such as collaboration or licensing arrangements with third parties or other strategic transactions. There are no assurances that we will be successful in obtaining an adequate level of financing to support our business plans when needed on acceptable 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 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 additional funds through collaboration or licensing arrangements with third parties or other strategic transactions, we may have to relinquish rights to our intellectual property, future revenue streams, research programs, or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise capital as and when needed, or on attractive terms, we may have to significantly delay, reduce, or discontinue the development and commercialization of our product candidates or scale back or terminate our pursuit of new in-licenses and acquisitions.

Current wording

We do not expect to generate revenue from any product candidates that we develop until we obtain regulatory approval for one or more of such product candidates and commercialize our products or enter into collaboration agreements with third parties. Because of the numerous risks and uncertainties associated with biopharmaceutical product development, we may never achieve or sustain profitability and, unless and until we are able to develop and commercialize our product candidates, we will need to continue to raise additional capital. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through public or private equity or debt financings, or potentially other capital sources, such as collaboration or licensing arrangements with third parties or other strategic transactions. There are no assurances that we will be successful in obtaining an adequate level of financing to support our business plans when needed on acceptable 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 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 additional funds through collaboration or licensing arrangements with third parties or other strategic transactions, we may have to relinquish rights to our intellectual property, future revenue streams, research programs, or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise capital as and when needed, or on attractive terms, we may have to significantly delay, reduce, or discontinue the development and commercialization of our product candidates or scale back or terminate our pursuit of new in-licenses and acquisitions.

Previous wording

We do not currently own or operate any manufacturing facility. We rely on CMOs to produce our product candidates in accordance with the FDA current cGMP regulations for use in our clinical studies. We have entered into development and manufacturing agreements with various CMOs relating to process development, manufacturing of drug substance and drug product, and quality testing of our product candidates. We expect to rely on our CMOs in the future for the manufacturing of our product candidates in order to expedite readiness for future clinical trials. Most of these CMOs have demonstrated capability in preparation of materials for commercialization. Additionally, we may decide to build our own manufacturing facility in the future to provide us greater flexibility and control over our clinical or commercial manufacturing needs.

Current wording

We do not currently own or operate any manufacturing facility. We rely on CMOs to produce our product candidates in accordance with the FDA current cGMP regulations for use in our clinical studies. We have entered into development and manufacturing agreements with various CMOs relating to process development, manufacturing of drug substance and drug product, and quality testing of our product candidates. We expect to rely on our CMOs in the future for the manufacturing of our product candidates in order to expedite readiness for future clinical trials. Most of these CMOs have demonstrated capability in preparation of materials for commercialization. Additionally, we may decide to build our own manufacturing facility in the future to provide us with greater flexibility and control over our clinical or commercial manufacturing needs.

Previous wording

Given our stage of development, we do not yet have a marketing or sales organization or commercial infrastructure; however, we intend to build the necessary sales, marketing and commercialization capabilities and infrastructure over time as our product candidates advance through clinical development. We expect to spend a significant amount in commercial development and marketing costs prior to obtaining regulatory and marketing approval of one or more of our product candidates.

Current wording

Given our stage of development, we do not yet have a fully established marketing or sales organization or commercial infrastructure; however, we have begun building foundational capabilities and intend to continue expanding the necessary sales, marketing and commercialization capabilities and infrastructure over time as our product candidates advance through clinical development and regulatory approval. We expect to spend a significant amount in commercial development and marketing costs prior to obtaining regulatory and marketing approval of one or more of our product candidates.

Previous wording

On June 27, 2024, our Registration Statement on Form S-1 for our IPO was declared effective, and, on July 1, 2024, we completed our IPO, pursuant to which we issued and sold 13,125,000 shares of our common stock at $16.00 price per share to the public. Net proceeds from the IPO were $193.3 million, after deducting underwriting discounts and commissions and other offering costs totaling $16.7 million.

Current wording

On July 1, 2024, we completed our IPO, pursuant to which we issued and sold 13,125,000 shares of our common stock at $16.00 price per share to the public. Net proceeds from the IPO were $193.3 million, after deducting underwriting discounts and commissions and other offering costs totaling $16.7 million. In connection with the IPO, on July 17, 2024, an existing investor and a holder of more than 5% of our capital stock, purchased an additional 2,500,000 shares of our common stock at the IPO price per share for total gross and net proceeds of $40.0 million in a private placement transaction (the “Concurrent Private Placement”).

Previous wording

On February 6, 2025, we entered into the Merger Agreement, with ACELYRIN and Merger Sub. Under the terms of the Merger Agreement, Merger Sub will merge with and into ACELYRIN, with ACELYRIN continuing as a direct wholly owned subsidiary of ours. The Merger Agreement was approved by the disinterested directors on our board and the board of directors of ACELYRIN and is subject to stockholder approval by the stockholders of each company and the satisfaction or waiver of other closing conditions.

Current wording

On February 6, 2025, we entered into a Merger Agreement with ACELYRIN and Merger Sub, a Delaware corporation and a direct wholly owned subsidiary. The Merger Agreement was approved by the disinterested directors on our board of directors and the board of directors of ACELYRIN and was approved by the stockholders of each company on May 13, 2025. On May 21, 2025, we completed the ACELYRIN Merger for a purchase consideration of approximately $238.1

Previous wording

confidence, declines in economic growth, increases in unemployment rates, recession risks and uncertainty about economic and geopolitical stability (for example, related to the ongoing conflicts in Ukraine and Israel and the surrounding areas). Further, the United States and other countries have imposed and may continue to impose new trade restrictions and export regulations, have levied tariffs and taxes on certain goods, and could significantly increase tariffs on a broad array of goods. For example, the current Trump administration has proposed or enacted tariffs and substantial changes to trade policies, which could adversely affect our business, including imposing tariffs on certain foreign products, most recently from China, that have and may result in retaliatory tariffs on U.S. goods and services. The effect of macroeconomic conditions may not be fully reflected in our results of operations until future periods. Moreover, negative macroeconomic conditions could adversely impact our ability to obtain financing in the future on terms acceptable to us, or at all. To date, the macroeconomic trends discussed above have not had a material adverse impact on our business, financial condition or results of operations. If, however, economic uncertainty increases or the global economy worsens, our business, financial condition and results of operations may be harmed.

Current wording

Our business and results of operations may be affected by worldwide economic conditions, which may continue to be impacted by global macroeconomic challenges and uncertainty in the markets, including severely diminished liquidity and credit availability, rising inflation and monetary supply shifts, rising interest rates, labor shortages, declines in consumer confidence, declines in economic growth, increases in unemployment rates, recession risks and uncertainty about economic and geopolitical stability (for example, related to the evolving U.S. and ex-U.S. tariff landscape). Further, the United States and other countries have imposed and may continue to impose new trade restrictions and export regulations, have levied tariffs and taxes on certain goods, and could continue to significantly increase tariffs on a broad array of goods. For example, in April 2025, the U.S. government imposed a 10% baseline global tariff and in August 2025, the United States imposed higher “reciprocal” tariffs on numerous other territories, including EU member states and South Korea. While the U.S. Supreme Court recently issued a ruling invalidating tariffs imposed by the Trump administration under the International Emergency Economic Powers Act, other tariffs imposed by the U.S. government remain in place, including the 10% global tariff imposed by the Trump administration under Section 122 of the Trade Act of 1974 following the U.S. Supreme Court decision. Moreover, the Bureau of Industry and Security, U.S. Department of Commerce, has initiated an investigation to determine whether pharmaceutical ingredients, including finished drug product, manufactured outside the United States pose a national security risk and should be subject to additional tariffs. The effect of macroeconomic conditions may not be fully reflected in our results of operations until future periods. Moreover, negative macroeconomic conditions could adversely impact our ability to obtain financing in the future on terms acceptable to us, or at all. To date, the macroeconomic trends discussed above have not had a material adverse impact on our business, financial condition or results of operations. If, however, economic uncertainty increases or the global economy worsens, our business, financial condition and results of operations may be harmed.

Previous wording

Our operating expenses consist of (i) research and development expenses and (ii) general and administrative expenses.

Current wording

Our operating expenses consist of (i) research and development expenses and (ii) general and administrative expenses, and include ACELYRIN’s operations subsequent to the Closing Date.

Previous wording

We have acquired and may continue to acquire the rights to develop and commercialize new product candidates. Upfront and milestone payments are accrued for and expensed as in process research and development (“IPR&D”) assets expense when the achievement of the milestone is probable up to the point of regulatory approval and, absent obtaining such approval, have no alternative future use. Milestone payments made after a product’s regulatory approval will be capitalized and amortized over the remaining useful life of the related product.

Current wording

We have acquired and may continue to acquire the rights to develop and commercialize new product candidates. Upfront payments related to acquired IPR&D assets are recognized as expenses when we determine that the assets acquired do not have alternative future uses. Milestone payments are accrued and expensed when the achievement of the milestone is probable up to the point of regulatory approval and, absent obtaining such approval, have no alternative future use. Milestone payments made after a product’s regulatory approval will be capitalized and amortized over the remaining useful life of the related product.

Previous wording

We expense research and development costs as incurred. Costs of certain activities are recognized based on an evaluation of the progress to completion of specific tasks. However, payments made prior to the receipt of goods or services that will be used or rendered for future research and development activities are deferred and capitalized as research and development prepaid expenses in our consolidated balance sheets. The capitalized amounts are recognized as expense as the goods are delivered or services are performed. Since our inception and through December 31, 2024, our external research and development expenses were primarily related to the discovery and advancement of programs under our TYK2 platform, including our two most advanced product candidates, ESK-001 and A-005. We use internal resources primarily for managing our research, process development, manufacturing and clinical development activities. In particular, with respect to internal costs, we deploy our personnel across all of our research and development activities as our employees work across multiple programs, and therefore the costs cannot be allocated to a particular product candidate or research program.

Current wording

We expense research and development costs as incurred. Costs of certain activities are recognized based on an evaluation of the progress to completion of specific tasks. However, payments made prior to the receipt of goods or services that will be used or rendered for future research and development activities are deferred and capitalized as research and development prepaid expenses in our consolidated balance sheets. The capitalized amounts are recognized as expense as the goods are delivered or services are performed. Since our inception and through December 31, 2025, our external research and development expenses were primarily related to the discovery and advancement of programs under our TYK2 platform, including our two most advanced product candidates, envu and A-005. We use internal resources primarily for managing our research, process development, manufacturing and clinical development activities. In particular, with respect to internal costs, we deploy our personnel across all of our research and development activities as our employees work across multiple programs, and therefore the costs cannot be allocated to a particular product candidate or research program.

Previous wording

A change in the outcome of any of these variables with respect to the development of any of our product candidates could significantly change the costs and timing associated with the development of that product candidate. We anticipate that our total research and development expenses in 2025 will increase compared to 2024 due primarily to higher costs for the development of our product candidates and ACELYRIN research and development activities, if the Merger closes.

Current wording

A change in the outcome of any of these variables with respect to the development of any of our product candidates could significantly change the costs and timing associated with the development of that product candidate.

Previous wording

We expect that our general and administrative expenses will increase substantially in the future as a result of expanding our operations, including hiring personnel, preparing for potential commercialization of our product candidates and facility occupancy costs, and support of general operations and ACELYRIN general and administrative activities, if the Merger closes. We also expect an increase in costs associated with being a public company, including costs related to accounting, audit, legal, consulting fees, regulatory and tax-related services associated with maintaining compliance with applicable Nasdaq and SEC requirements, additional director and officer insurance costs, and investor and public relations costs.

Current wording

We expect that our general and administrative expenses will increase substantially in the future as a result of expanding our operations, including hiring personnel, preparing for potential commercialization of our product candidates and facility occupancy costs. We also expect to continue incurring costs associated with being a public company, including costs related to accounting, audit, legal, consulting fees, regulatory and tax-related services associated with maintaining compliance with applicable Nasdaq and SEC requirements, additional director and officer insurance costs, and investor and public relations costs.

Previous wording

Other income (expense) consists primarily of interest income, including amortization of premiums and accretion of discounts on marketable securities and change in fair value of derivative liability.

Current wording

Other income (expense) consists primarily of interest income, including amortization of premiums and accretion of discounts on marketable securities, gain on bargain purchase and change in fair value of derivative liability.

Previous wording

In May 2023 and in March 2024, in connection with our redeemable convertible preferred stock financings, we issued options to purchase additional shares of redeemable convertible preferred stock at a specified price, which were accounted for as derivative liabilities. Changes in fair value of these derivative liabilities were included in the other income (loss) in the consolidated statement of operations and comprehensive loss for each reporting period until the derivatives were exercised or expired.

Current wording

In March 2024, in connection with our redeemable convertible preferred stock financings, we issued options to purchase additional shares of redeemable convertible preferred stock at a specified price, which were accounted for as derivative liabilities. Changes in fair value of these derivative liabilities were included in the other income (loss) in the consolidated statement of operations and comprehensive loss for each reporting period until the derivatives were settled in May 2024.

Previous wording

Research and development expenses increased by $127.9 million, to $265.6 million for the year ended December 31, 2024, from $137.7 million for year ended December 31, 2023.

Current wording

Research and development expenses increased by $120.4 million, to $386.0 million for the year ended December 31, 2025, from $265.6 million for year ended December 31, 2024.

Previous wording

Milestones related to previously acquired IPR&D assets for the year ended December 31, 2024, included a $23.0 million clinical milestone payment made in connection with the FronThera Acquisition. No clinical milestones were achieved or probable during the year ended December 31, 2023.

Current wording

Milestones related to previously acquired IPR&D assets for the year ended December 31, 2024, included a $23.0 million clinical milestone payment made in connection with the FronThera Acquisition.

Previous wording

CRO, CMO and clinical trials expenses increased by $82.5 million, to $151.4 million for the year ended December 31, 2024, from $69.0 million for the year ended December 31, 2023, primarily due to an increase in clinical trial and CRO expenses due to increased activities related to our clinical trials for ESK-001 and A-005 and an increase in CMO expenses associated with manufacturing of clinical supplies to support our trials.

Current wording

CRO, CMO and clinical trials expenses increased by $79.7 million, to $231.1 million for the year ended December 31, 2025, from $151.4 million for the year ended December 31, 2024, primarily due to an increase in clinical trial and CRO expenses related to the progression of our clinical trials for envu and other programs, including costs to support acceleration of clinical trial activities for our Phase 3 ONWARD clinical program, partially offset by a decrease in CMO expenses associated with manufacturing of clinical supplies to support our trials.

Previous wording

Professional consulting services expenses increased by $6.0 million, to $19.2 million for the year ended December 31, 2024, from $13.2 million for the year ended December 31, 2023, primarily due to increased support for our clinical trials for ESK-001, A-005 and other research programs.

Current wording

Professional consulting services expenses increased by $11.0 million, to $30.2 million for the year ended December 31, 2025, from $19.2 million for the year ended December 31, 2024, primarily due to services to support our clinical trial for envu and other programs.

Previous wording

Other research and development costs decreased by $1.2 million, to $10.3 million for the year ended December 31, 2024, from $11.5 million for the year ended December 31, 2023, primarily due to timing of preclinical studies to support our clinical trials for ESK-001 and A-005.

Current wording

Other research and development costs decreased by $1.2 million, to $9.1 million for the year ended December 31, 2025, from $10.3 million for the year ended December 31, 2024, primarily due to the timing of preclinical studies.

Previous wording

Personnel-related costs increased by $14.7 million, to $46.8 million for the year ended December 31, 2024, from $32.1 million for the year ended December 31, 2023, primarily due to increased research and development headcount and included an increase in stock-based compensation expense of $5.4 million as a result of additional stock options granted, which included awards granted under the 2024 POP.

Current wording

Personnel-related costs increased by $45.9 million, to $92.7 million for the year ended December 31, 2025, from $46.8 million for the year ended December 31, 2024, primarily due to an increase in research and development headcount and severance costs related to the ACELYRIN Merger, and included an increase in stock-based compensation expense of $11.2 million resulting from equity awards assumed in the ACELYRIN Merger and additional stock options granted.

Previous wording

Facilities and overhead costs increased by $2.9 million, to $14.9 million for the year ended December 31, 2024, from $12.0 million for the year ended December 31, 2023, primarily due to an increase in software license costs and depreciation expenses allocated to research and development activities.

Current wording

Facilities and overhead costs increased by $8.0 million, to $22.9 million for the year ended December 31, 2025, from $14.9 million for the year ended December 31, 2024, primarily due to an increase in facility expenses allocated to research and development activities and an increase in information technology costs.

Previous wording

During the years ended December 31, 2024 and 2023, our external research and development expenses were primarily related to the clinical development of our ESK-001 program and, to a lesser extent, advancing our A-005 product candidate and research pipeline. The following table summarizes our external costs by program for the years ended December 31, 2024 and 2023 (in thousands):

Current wording

During the years ended December 31, 2025 and 2024, our external research and development expenses were primarily related to the clinical development of our envu program and, to a lesser extent, the lonigutamab and A-005 development programs and our research pipeline.

Previous wording

General and administrative expenses increased by $14.7 million, to $35.2 million for the year ended December 31, 2024, from $20.5 million for the year ended December 31, 2023.

Current wording

General and administrative expenses increased by $56.7 million, to $91.9 million for the year ended December 31, 2025, from $35.2 million for the year ended December 31, 2024.

Previous wording

Personnel-related expenses increased by $9.0 million, to $20.0 million for the year ended December 31, 2024, from $11.0 million for the year ended December 31, 2023, primarily due to increased general and administrative headcount and included an increase in stock-based compensation expense of $5.5 million as a result of additional stock options granted, which included awards granted under the 2024 POP.

Current wording

Personnel-related expenses increased by $28.8 million, to $48.9 million for the year ended December 31, 2025, from $20.0 million for the year ended December 31, 2024, primarily due an increase in general and administrative headcount and severance costs related to the ACELYRIN Merger, and included an increase in stock-based compensation expense of $12.9 million resulting from equity awards assumed in the ACELYRIN Merger and additional stock options granted.

Previous wording

Professional consulting services expenses increased by $5.4 million, to $13.3 million for the year ended December 31, 2024, from $7.9 million for the year ended December 31, 2023, primarily due to an increase in consulting services to support our growth, public company requirements, business development and market analysis, and an increase in recruiting costs.

Current wording

Professional consulting services expenses increased by $28.1 million, to $41.4 million for the year ended December 31, 2025, from $13.3 million for the year ended December 31, 2024, primarily due to the ACELYRIN Merger transaction costs, a loss reserve and an increase in consulting, audit and tax, legal and accounting services to support our growth, public company requirements and business development.

Previous wording

Other income (expense), net increased by $3.3 million, to $6.5 million for the year ended December 31, 2024, from $3.2 million for the year ended December 31, 2023.

Current wording

Other income (expense), net increased by $195.4 million, to $201.9 million for the year ended December 31, 2025, from $6.5 million for the year ended December 31, 2024.

Previous wording

Interest income increased by $8.7 million, to $12.0 million for the year ended December 31, 2024, from $3.4 million for the year ended December 31, 2023, primarily as a result of higher balances of cash equivalents and marketable securities.

Current wording

Interest income increased by $2.2 million, to $14.2 million for the year ended December 31, 2025, from $12.0 million for the year ended December 31, 2024, primarily as a result of higher balances of cash equivalents and marketable securities.

Previous wording

Since our inception, we have not generated any revenue from product sales and have incurred significant operating losses and negative cash flows from our operations. To date, we have primarily funded our operations with proceeds from sales of shares of our common stock and redeemable convertible preferred stock and the issuance of convertible promissory notes in private placements and, more recently, from our IPO and Concurrent Private Placement. In July 2024, we closed our IPO and the Concurrent Private Placement and received net proceeds of $193.3 million and $40.0 million, respectively. See “—Recent Development” above for a discussion of the proposed Merger.

Current wording

Since our inception, we have not generated any revenue from product sales and have incurred significant operating losses and negative cash flows from our operations. To date, we have primarily funded our operations through the issuance of common stock, including in connection with the ACELYRIN Merger, our IPO and Concurrent Private Placement, the issuance of redeemable convertible preferred stock and convertible promissory notes in private placements and, most recently, our public offering of common stock which closed on January 9, 2026.

Previous wording

Based on our current operating plan, our existing cash, cash equivalents and marketable securities of $288.3 million as of December 31, 2024, will not be sufficient to meet our operating and capital requirements for at least 12 months from the date of issuance of our consolidated financial statements included in Part II, Item 8. of this Annual Report on Form 10-K and there is substantial doubt about our ability to continue as a going concern. We expect to continue to incur substantial losses for the foreseeable future, and our transition to profitability will depend upon successful development, approval and commercialization of our product candidates and upon achievement of sufficient revenues to support our cost structure. We do not expect to generate any revenue from commercial product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates. We may never achieve profitability, and unless we do and until then, we will need to continue to raise additional capital. We will need to raise significant additional capital to fund ongoing research and development activities and maintain future operations. We plan to monitor expenses and may raise additional capital through a combination of public and private equity, debt financings, strategic alliances, and licensing arrangements. Our ability to access capital when needed is not assured and, if capital is not available to us when, and in the amounts, needed, on the terms which are favorable, we could be required to delay, scale back, or abandon some or all of our planned development programs and other operations, which could materially harm our business, financial condition and results of operations.

Current wording

Based on our current operating plan, our existing cash, cash equivalents and marketable securities of $308.5 million as of December 31, 2025, as well as net proceeds of $324.4 million, after deducting underwriting discounts and commissions, from our public offering of common stock, which closed on January 9, 2026, will be sufficient to meet our operating and capital requirements for at least 12 months from the date of issuance of our consolidated financial statements included in Part II. Item 8 of this Annual Report on Form 10-K. We expect to continue to incur substantial losses for the foreseeable future, and our transition to profitability will depend upon successful development, approval and commercialization of our product candidates and upon achievement of sufficient revenues to support our cost structure. We do not expect to generate any revenue from commercial product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates. We may never achieve profitability, and unless we do and until then, we will need to continue to raise additional capital. We will need to raise significant additional capital to fund ongoing research and development activities and maintain future operations. We continuously monitor and, where necessary, may reduce our operating expenses in response to our clinical development progress and our ability and need to raise additional capital through a combination of public and private equity, debt financings, strategic alliances, and licensing arrangements. For example, should any of our ongoing trials not meet our clinical development objectives, we may scale back or discontinue related activities and reallocate our working capital to extend our ability to meet our operating and capital requirements. Our ability to access capital when needed is not assured and, if capital is not available to us when, and in the amounts, needed, on the terms which are favorable, we could be required to delay, scale back, or abandon some or all of our planned development programs and other operations, which could materially harm our business, financial condition and results of operations.

Previous wording

Our primary uses of cash are to fund our operations, which consist primarily of research and development expenditures related to our programs and, to a lesser extent, general and administrative expenditures. We anticipate that we will continue to incur significant and increasing expenses for the foreseeable future as we continue to advance our product candidates, expand our corporate infrastructure, including the costs associated with being a public company, further our research and development initiatives for our product candidates, and incur costs associated with potential commercialization. In addition, we anticipate committing substantial capital resources to the transactions contemplated by the Merger Agreement and, assuming the consummation of those transactions, the anticipated integration and development activities related to the acquired ACELYRIN business. We are subject to all of the risks typically related to the development of new drug candidates, and we may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. We anticipate that we will need substantial additional funding in connection with our continuing operations.

Current wording

Our primary uses of cash are to fund our operations, which consist primarily of research and development expenditures related to our programs and, to a lesser extent, general and administrative expenditures. We anticipate that we will continue to incur significant and increasing expenses for the foreseeable future as we continue to advance our product candidates, expand our corporate infrastructure, including the costs associated with being a public company, further our research and development initiatives for our product candidates, and incur costs associated with potential commercialization. We are subject to all of the risks typically related to the development of new drug candidates, and we may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. We anticipate that we will need substantial additional funding in connection with our continuing operations.

Previous wording

Net cash used in operating activities was $255.1 million and $130.0 million for the years ended December 31, 2024 and 2023, respectively.

Current wording

Net cash used in operating activities was $369.5 million and $255.1 million for the years ended December 31, 2025 and 2024, respectively.

Previous wording

Net cash used in operating activities for the year ended December 31, 2023, was due to our net loss for the period of $155.0 million, partially offset by changes in non-cash items of $13.0 million and changes in operating assets and liabilities of

Current wording

Net cash used in operating activities for the year ended December 31, 2025 was due to our net loss for the period of $243.3 million and changes in non-cash items totaling $144.0 million, partially offset by changes in operating assets and liabilities of $17.8 million. Non-cash items included $187.9 million related to gain on bargain purchase in connection with the ACELYRIN Merger and net accretion of discounts on marketable securities of $5.3 million, partially offset by $43.5 million related to stock-based compensation expense, $3.5 million related to depreciation and amortization, $1.7 million related to non-cash lease expense and $0.5 million related to impairment of long-lived assets. The changes in operating assets and liabilities primarily included a decrease of $17.2 million in other prepaid expenses and other assets, a decrease of $11.5 million in research and development prepaid expenses, an increase of $6.0 million in other accrued expenses and current liabilities, an increase of $4.1 million in deferred revenue, and an increase of $2.1 million in research and development accrued expenses, partially offset by an $8.6 million decrease in deferred tax liability, a decrease of $6.0 million in accounts payable, an increase of $5.5 million in other assets, non-current and a decrease of $3.2 million in operating lease liabilities.

Previous wording

Net cash provided by investing activities of $60.5 million for the year ended December 31, 2023, was related to proceeds from maturities of marketable securities of $76.3 million, partially offset by purchases of marketable securities of $11.3 million and purchases of property and equipment of $4.5 million.

Current wording

Net cash provided by investing activities of $287.9 million for the year ended December 31, 2025, was related to maturities of marketable securities of $448.0 million and cash, cash equivalents and restricted cash acquired in connection with the ACELYRIN Merger of $49.7 million, partially offset by purchases of marketable securities of $209.2 million and by purchases of property and equipment of $0.7 million.

Previous wording

Net cash used in investing activities of $113.8 million for the year ended December 31, 2024, was related to purchases of marketable securities of $240.1 million and purchases of property and equipment of $1.7 million, partially offset by proceeds from maturities of marketable securities of $128.0 million.

Current wording

Net cash used in investing activities of $113.8 million for the year ended December 31, 2024, was related to purchases of marketable securities of $240.1 million and purchases of property and equipment of $1.7 million, partially offset by maturities of marketable securities of $128.0 million.

Previous wording

Net cash provided by financing activities of $492.4 million for the year ended December 31, 2024, included net proceeds of $258.5 million from the issuance of our Series C redeemable convertible preferred stock and related derivative liability, net of offering costs, $193.3 million net proceeds from our IPO, net of underwriter discounts and commissions and other offering costs, gross and net proceeds of $40.0 million from a private placement transaction and proceeds of $0.6 million from the issuance of common stock upon exercise of stock options.

Current wording

Net cash provided by financing activities of $492.4 million for the year ended December 31, 2024, included $258.5 million proceeds from the issuance of redeemable convertible preferred stock and derivative liability, net of offering costs, $193.3 million proceeds from initial public offering, net of underwriter discounts and commissions and other offering costs, $40.0 million proceeds from a private placement transaction and $0.6 million proceeds from issuance of common stock upon exercise of stock options.

Previous wording

We have operating lease arrangements for office and laboratory space in South San Francisco, California. As of December 31, 2024, we had total undiscounted lease payment obligations under non-cancelable leases of $5.0 million payable in the 12 months following December 31, 2024 and $43.4 million payable thereafter.

Current wording

We have operating lease arrangements for office and laboratory space in South San Francisco, California and office space in Southern California. As of December 31, 2025, we had total undiscounted lease payment obligations under non-cancelable leases of $8.5 million payable in the 12 months following December 31, 2025, and $44.5 million payable thereafter.