Pipeline and Milestones - Alumis expects topline data from Phase 3 ONWARD trials for envudeucitinib in moderate-to-severe plaque psoriasis in early 1Q 2026[11] - Alumis anticipates topline data from Phase 2b LUMUS trial in systemic lupus erythematosus in 3Q 2026[11] - Alumis plans to initiate a Phase 2 clinical trial for A-005 in multiple sclerosis in 1H 2026[11] - Alumis is evaluating the development program for lonigutamab in thyroid eye disease[12] - Alumis expects Phase 1 data for its next program in 2026[12] Financial Position - Alumis had $486.3 million in cash as of June 30, 2025, providing runway into 2027[11] Envudeucitinib (TYK2 Inhibitor) - Envudeucitinib demonstrated a 15-20% increase in clinical response (PASI) with maximal target inhibition[23] - In the STRIDE trial, Envudeucitinib 40 mg BID showed a 64.1% PASI-75 response at Week 12[39] - Approximately 92% of diagnosed psoriasis patients are not treated with a biologic therapy, representing a market opportunity for Envudeucitinib[35] - Alumis is receiving $40 million near-term for Japan, <5% of Worldwide Psoriasis Market (estimated at $600M in 2024)[69] A-005 (CNS-Penetrant TYK2 Inhibitor) - A-005 achieves a CSF:Plasma (free drug) ratio of approximately 1:1, indicating full CNS penetration[75]

PART I [Item 1. Financial Statements (unaudited)](index=6&type=section&id=Item%201.%20Financial%20Statements%20%28unaudited%29) This section presents the unaudited condensed consolidated financial statements, including balance sheets, statements of operations, and cash flows, showing a net loss of **$55.3 million** for the quarter and a decrease in total assets [Condensed Consolidated Balance Sheets](index=6&type=section&id=Condensed%20Consolidated%20Balance%20Sheets) The balance sheet as of March 31, 2025, shows total assets decreased to **$436.5 million** from **$491.1 million** at year-end 2024, primarily due to reduced cash and marketable securities Condensed Consolidated Balance Sheet Highlights (in thousands) | Account | March 31, 2025 | December 31, 2024 | | :--- | :--- | :--- | | **Assets** | | | | Cash and cash equivalents | $58,271 | $73,890 | | Short-term marketable securities | $352,321 | $373,990 | | Total current assets | $429,492 | $480,987 | | **Total assets** | **$436,504** | **$491,141** | | **Liabilities & Equity** | | | | Total current liabilities | $23,303 | $26,578 | | **Total liabilities** | **$29,273** | **$32,848** | | **Total stockholders' equity (deficit)** | **$407,231** | **$458,293** | [Condensed Consolidated Statements of Operations and Comprehensive Loss](index=7&type=section&id=Condensed%20Consolidated%20Statements%20of%20Operations%20and%20Comprehensive%20Loss) The company reported a net loss of **$55.3 million** for the three months ended March 31, 2025, an increase from **$35.0 million** in the prior year, despite a decrease in total operating expenses Statement of Operations Highlights (in thousands, except per share data) | Metric | Three Months Ended March 31, 2025 | Three Months Ended March 31, 2024 | | :--- | :--- | :--- | | Research and development | $42,138 | $58,032 | | General and administrative | $17,717 | $24,742 | | **Total operating expenses** | **$59,855** | **$82,774** | | Loss from operations | ($59,855) | ($82,774) | | Interest income | $4,658 | $9,150 | | Other income (expense), net | ($67) | $38,651 | | **Net loss** | **($55,264)** | **($34,973)** | | Net loss per share, basic and diluted | ($0.55) | ($0.36) | [Condensed Consolidated Statements of Cash Flows](index=9&type=section&id=Condensed%20Consolidated%20Statements%20of%20Cash%20Flows) Net cash used in operating activities improved to **$39.0 million** in Q1 2025 from **$57.3 million** in Q1 2024, with overall cash decreasing by **$15.6 million** during the quarter Cash Flow Summary (in thousands) | Activity | Three Months Ended March 31, 2025 | Three Months Ended March 31, 2024 | | :--- | :--- | :--- | | Net cash used in operating activities | ($38,955) | ($57,299) | | Net cash provided by investing activities | $23,331 | $100,896 | | Net cash provided by financing activities | $5 | $2,807 | | **Net (decrease) increase in cash** | **($15,619)** | **$46,404** | | Cash at end of period | $58,815 | $264,501 | [Notes to Condensed Consolidated Financial Statements](index=10&type=section&id=Notes%20to%20Condensed%20Consolidated%20Financial%20Statements) The notes detail liquidity, accounting policies, and significant events, including the termination of the izokibep license, the merger agreement with Alumis Inc., and a **$2.9 million** impairment charge - The company's **$411.1 million** in cash, cash equivalents, and short-term marketable securities as of March 31, 2025, are deemed sufficient to fund operations for at least the next 12 months[33](index=33&type=chunk) - The License and Collaboration Agreement with Affibody for izokibep was terminated on January 31, 2025, eliminating future material financial obligations[79](index=79&type=chunk) - A merger agreement with Alumis Inc. was entered into on February 6, 2025, approved by stockholders on May 13, 2025, and is expected to close in Q2 2025[125](index=125&type=chunk)[126](index=126&type=chunk) - A non-cash impairment expense of **$2.9 million** was recorded for the sublease of the South San Francisco office space[90](index=90&type=chunk) [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](index=28&type=section&id=Item%202.%20Management%27s%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Management discusses the company's financial condition and results, highlighting the pending merger with Alumis, the strategic shift to lonigutamab, and decreased operating expenses due to restructuring - The merger agreement with Alumis Inc. was approved by stockholders and is expected to close in Q2 2025, delaying the Phase 3 program for lonigutamab until completion[130](index=130&type=chunk)[131](index=131&type=chunk)[137](index=137&type=chunk) - Following an August 2024 restructuring, the company ceased izokibep development to focus primarily on its lonigutamab clinical program for Thyroid Eye Disease (TED)[138](index=138&type=chunk) - As of March 31, 2025, the company held **$411.1 million** in cash, cash equivalents, restricted cash, and short-term marketable securities, sufficient to fund operations for at least the next 12 months[144](index=144&type=chunk) [Results of Operations](index=34&type=section&id=Results%20of%20Operations) Total operating expenses decreased by **28%** to **$59.9 million** in Q1 2025, driven by reduced R&D and G&A costs, while total other income significantly declined due to the absence of prior-year non-recurring income Operating Expenses Comparison (in thousands) | Expense Category | Q1 2025 | Q1 2024 | Change ($) | Change (%) | | :--- | :--- | :--- | :--- | :--- | | Research and development | $42,138 | $58,032 | ($15,894) | (27%) | | General and administrative | $17,717 | $24,742 | ($7,025) | (28%) | | **Total operating expenses** | **$59,855** | **$82,774** | **($22,919)** | **(28%)** | CRO and CMO Expenses by Program (in thousands) | Program | Q1 2025 | Q1 2024 | | :--- | :--- | :--- | | Izokibep | $8,124 | $39,229 | | Lonigutamab | $20,229 | $2,052 | | **Total** | **$28,324** | **$41,384** | - The decrease in G&A expenses was primarily due to a **$13.2 million** reduction in stock-based compensation, partially offset by a **$4.9 million** increase in professional services fees related to the merger[172](index=172&type=chunk)[173](index=173&type=chunk) [Liquidity, Capital Resources and Capital Requirements](index=36&type=section&id=Liquidity%2C%20Capital%20Resources%20and%20Capital%20Requirements) The company's liquidity, primarily from its May 2023 IPO, totals **$411.1 million** as of March 31, 2025, deemed sufficient for 12 months, with future needs dependent on clinical trials and the Alumis merger - The company's primary liquidity sources include its May 2023 IPO and sales of redeemable convertible preferred stock[177](index=177&type=chunk) - Future funding needs are subject to risks such as clinical trial timing and results, restructuring costs, and the consummation of the Merger[182](index=182&type=chunk) [Item 3. Quantitative and Qualitative Disclosures About Market Risk](index=39&type=section&id=Item%203.%20Quantitative%20and%20Qualitative%20Disclosures%20About%20Market%20Risk) As a smaller reporting company, the company is exempt from providing quantitative and qualitative disclosures about market risk - As a smaller reporting company, Acelyrin is not required to provide quantitative and qualitative disclosures about market risk[193](index=193&type=chunk) [Item 4. Controls and Procedures](index=39&type=section&id=Item%204.%20Controls%20and%20Procedures) Management concluded that the company's disclosure controls and procedures were effective as of March 31, 2025, with no material changes to internal control over financial reporting during the quarter - The Chief Executive Officer and Principal Financial Officer concluded that the company's disclosure controls and procedures were effective as of March 31, 2025[195](index=195&type=chunk) - No material changes occurred during the quarter affecting the company's internal control over financial reporting[196](index=196&type=chunk) PART II OTHER INFORMATION [Item 1. Legal Proceedings](index=41&type=section&id=Item%201.%20Legal%20Proceedings) The company faces a federal securities class action lawsuit regarding izokibep trial statements and two stockholder complaints seeking to enjoin the Alumis merger due to alleged disclosure failures - A federal securities class action lawsuit (Boukadoum v. Acelyrin, Inc. et al.) was filed alleging violations related to the izokibep Phase 2b trial, with a motion to dismiss pending[199](index=199&type=chunk) - Two stockholder complaints were filed in April 2025, alleging material disclosure failures regarding the Alumis merger and seeking to enjoin it[200](index=200&type=chunk)[201](index=201&type=chunk) [Item 1A. Risk Factors](index=42&type=section&id=Item%201A.%20Risk%20Factors) This section outlines significant investment risks, including uncertainties surrounding the Alumis merger, the company's history of losses, dependence on lonigutamab, substantial financing needs, and various operational and market challenges - The pending merger with Alumis is subject to closing conditions and uncertainties, and its non-completion could negatively impact financial performance and stock price[223](index=223&type=chunk)[224](index=224&type=chunk) - The company is a clinical-stage biopharma with no approved products, a history of substantial losses, including a **$792.2 million** accumulated deficit as of March 31, 2025, and expects further losses[210](index=210&type=chunk)[230](index=230&type=chunk) - Future success is substantially dependent on the ability to develop and commercialize the lead product candidate, lonigutamab, for Thyroid Eye Disease (TED)[216](index=216&type=chunk) - Substantial additional financing will be required, and failure to obtain it could lead to delays, reductions, or termination of product development[212](index=212&type=chunk) [Item 2. Unregistered Sales of Equity Securities and Use of Proceeds](index=98&type=section&id=Item%202.%20Unregistered%20Sales%20of%20Equity%20Securities%20and%20Use%20of%20Proceeds) There were no unregistered sales of equity securities during the reported period - There were no unregistered sales of equity securities in the reported period[491](index=491&type=chunk) [Item 5. Other Information](index=98&type=section&id=Item%205.%20Other%20Information) This section discloses the termination of a Rule 10b5-1 trading plan by the Chief Medical Officer and the approval of an amended severance plan contingent on the merger closing - Chief Medical Officer Shephard Mpofu, M.D., terminated his Rule 10b5-1 trading plan on March 11, 2025, with no shares sold under it[493](index=493&type=chunk) - Contingent on the merger closing, the board approved an Amended Severance Plan on May 8, 2025, enhancing severance benefits and extending vested stock option exercise periods for eligible employees[494](index=494&type=chunk)[495](index=495&type=chunk) [Item 6. Exhibits](index=99&type=section&id=Item%206.%20Exhibits) This section lists exhibits filed with the Form 10-Q, including certifications and interactive data files, and incorporates previously filed documents by reference

Core Viewpoint - ACELYRIN, Inc. has received stockholder approval for its merger with Alumis Inc., which is expected to enhance value through the combination of their complementary pipelines and organizations [1][2]. Group 1: Merger Details - The merger agreement stipulates that ACELYRIN stockholders will receive 0.4814 shares of Alumis common stock for each share of ACELYRIN common stock owned at the closing of the transaction [1]. - The transaction is anticipated to be completed in the second quarter of 2025 [3]. Group 2: Company Background - ACELYRIN, Inc. focuses on developing transformative medicines in immunology, with its lead program being lonigutamab, a monoclonal antibody for treating thyroid eye disease [5]. Group 3: Leadership Statements - The CEO of ACELYRIN expressed appreciation for stockholder support, indicating confidence in the merger as a value-maximizing strategy [2].

Core Viewpoint - Alumis Inc. has received stockholder approval for its merger with ACELYRIN, INC., marking a significant step towards closing the transaction and enhancing its capabilities in developing therapies for immune-mediated diseases [1][2][3] Company Overview - Alumis Inc. is a clinical-stage biopharmaceutical company focused on developing oral therapies using a precision approach to improve clinical outcomes for patients with immune-mediated diseases [4] - The company utilizes a proprietary precision data analytics platform to build a pipeline of molecules targeting a wide range of immune-mediated diseases, both as monotherapy and combination therapies [4] - Alumis' leading product candidate, ESK-001, is an oral, selective small molecule inhibitor currently being evaluated for moderate-to-severe plaque psoriasis and systemic lupus erythematosus [4] Merger Details - The merger with ACELYRIN is anticipated to close in the second quarter of 2025, pending the fulfillment of customary closing conditions [3] - Martin Babler, President and CEO of Alumis, expressed gratitude to stockholders for their support and emphasized the goal of maximizing the value of their portfolio post-merger [2] Future Prospects - The merger is expected to provide Alumis with a strengthened financial foundation, enabling the advancement of breakthroughs in the treatment of immune-mediated diseases [2]

Core Viewpoint - ACELYRIN, INC. is urging its stockholders to vote in favor of the proposed merger with Alumis Inc., supported by a recommendation from Institutional Shareholder Services (ISS) [1][2]. Group 1: Proposed Transaction - The special meeting for stockholders to vote on the merger is scheduled for May 13, 2025 [2]. - ISS has recommended that stockholders vote "FOR" the merger, indicating it is the best path to maximize shareholder value [2][3]. - The merger is the result of a comprehensive process led by independent directors, aimed at creating a stronger, diversified company [2]. Group 2: Company Overview - ACELYRIN is a late-stage clinical biopharma company focused on developing transformative medicines in immunology [1][4]. - The company's lead program, lonigutamab, is a monoclonal antibody targeting IGF-1R for treating thyroid eye disease [4]. Group 3: Advisory and Legal Support - Guggenheim Securities, LLC is serving as the financial advisor for ACELYRIN, while Fenwick & West LLP and Paul Hastings LLP are providing legal counsel [3].

Core Viewpoint - ACELYRIN, Inc. expresses confidence that the proposed merger with Alumis Inc. is the best path forward and maximizes value for stockholders [2][3] Company Overview - ACELYRIN is a late-stage clinical biopharma company focused on developing transformative medicines in immunology [2] - The merger with Alumis is seen as a strategic move to create a leading clinical-stage immunology company with a diversified portfolio [8] Merger Details - The ACELYRIN Board recommends stockholders vote "FOR" the merger, emphasizing the importance of every vote [5] - The merger agreement reflects a significant increase in ACELYRIN stockholders' ownership in the combined company, retaining approximately 48% ownership [8] - The merger follows a comprehensive review process by an independent transaction committee [8] Stockholder Engagement - The Board urges stockholders to protect their investment value and not be swayed by short-term focused investors [4] - A Special Meeting of stockholders is scheduled for May 13, 2025, to vote on the merger [1][5] Rights Plan - ACELYRIN adopted a limited duration rights plan in response to a rapid accumulation of its stock by Tang Capital, aiming to maximize stockholder value [6]

Core Viewpoint - The merger between Alumis Inc. and ACELYRIN, INC. has been amended to provide increased ownership for ACELYRIN stockholders, with the revised exchange ratio allowing Alumis stockholders to own approximately 52% and ACELYRIN stockholders to own approximately 48% of the combined company on a fully diluted basis, maximizing potential value for both parties [1][2]. Company Overview - Alumis Inc. is a clinical-stage biopharmaceutical company focused on developing therapies for immune-mediated diseases using a precision approach [10]. - ACELYRIN, INC. is a late-stage clinical biopharma company dedicated to accelerating the development and commercialization of transformative medicines, with its lead program targeting thyroid eye disease [11]. Merger Details - The amended agreement allows ACELYRIN stockholders to receive 0.4814 shares of Alumis common stock for each share of ACELYRIN common stock owned, representing a significant increase in ownership compared to the original merger terms [2]. - The merger is expected to create a leading clinical-stage immunology company with a diversified portfolio of product candidates, enhancing financial flexibility and advancing a late-stage pipeline [5][3]. Financial Position - Alumis reported a pro forma cash position of approximately $737 million as of December 31, 2024, which is expected to support the combined company's pipeline and operational needs into 2027 [5]. - Stockholders representing approximately 62% of Alumis voting common stock and about 24% of ACELYRIN common stock have entered into voting agreements in support of the transaction [6]. Upcoming Events - A Special Meeting of Stockholders for both companies is scheduled for May 13, 2025, where stockholders will vote on the merger [8][7].

Part I [Business](index=8&type=section&id=Item%201.%20Business) ACELYRIN, a clinical biopharmaceutical company, focuses on lonigutamab for Thyroid Eye Disease after a 2024 restructuring and pending merger with Alumis - On February 6, 2025, ACELYRIN entered into an Agreement and Plan of Merger with Alumis Inc., under which ACELYRIN will become a wholly owned subsidiary of Alumis[33](index=33&type=chunk) - The company's lead product candidate is lonigutamab, a subcutaneously delivered monoclonal antibody targeting IGF-1R for the treatment of Thyroid Eye Disease (TED)[34](index=34&type=chunk) - In August 2024, the company implemented a restructuring plan to suspend new internal investment in the izokibep program and focus primarily on the lonigutamab clinical program, subsequently terminating the license agreement with Affibody[40](index=40&type=chunk) - The SLRN-517 program was suspended in August 2024, and the corresponding license agreement with Novelty Nobility was terminated effective January 16, 2025[41](index=41&type=chunk) - The company acquired ValenzaBio, Inc. in an all-stock transaction on January 4, 2023, which added lonigutamab to its pipeline[44](index=44&type=chunk)[66](index=66&type=chunk) - ACELYRIN relies on third-party CMOs for the manufacturing of its product candidates and does not own or operate any manufacturing facilities[63](index=63&type=chunk) [Risk Factors](index=23&type=section&id=Item%201A.%20Risk%20Factors) The company faces significant risks from its pending merger, limited operating history, substantial losses, and reliance on its lead product candidate - The merger with Alumis is subject to various closing conditions, including stockholder and governmental approvals, and there is no assurance it will be completed, potentially delaying the Phase 3 LONGITUDE program for lonigutamab[121](index=121&type=chunk)[126](index=126&type=chunk) - ACELYRIN is a clinical-stage company with no approved products and a history of substantial losses, with an accumulated deficit of **$736.9 million** as of December 31, 2024, anticipating increasing losses for the foreseeable future[19](index=19&type=chunk)[128](index=128&type=chunk) - The company's business depends entirely on the success of its product candidates, with a primary focus on lonigutamab for TED, having previously suspended development of izokibep and SLRN-517 after expending significant resources[24](index=24&type=chunk)[153](index=153&type=chunk)[170](index=170&type=chunk) - The company faces significant competition for lonigutamab from the sole approved product for TED, Tepezza, as well as from other product candidates in late-stage clinical development by third parties[156](index=156&type=chunk) - ACELYRIN relies on third parties for critical functions, including in-licensing intellectual property (e.g., from Pierre Fabre for lonigutamab), conducting clinical trials (CROs), and manufacturing its product candidates (CMOs), exposing it to risks of non-performance and supply chain disruptions[234](index=234&type=chunk)[325](index=325&type=chunk)[334](index=334&type=chunk) - A purported federal securities class action lawsuit was filed against the company in November 2023 related to disclosures about the Phase 2b trial of izokibep in HS, which could result in substantial damages and divert management's attention[384](index=384&type=chunk) [Unresolved Staff Comments](index=77&type=section&id=Item%201B.%20Unresolved%20Staff%20Comments) The company reports no unresolved staff comments - None[386](index=386&type=chunk) [Cybersecurity](index=77&type=section&id=Item%201C.%20Cybersecurity) The company integrates cybersecurity risk management into its overall processes, overseen by an IT Steering Committee and audit committee - Cybersecurity risk management is integrated into the company's overall risk management processes, with an IT Steering Committee (ITSC) composed of senior management meeting at least quarterly to oversee the framework[387](index=387&type=chunk) - The board of directors' audit committee is responsible for overseeing cybersecurity and information technology risk management, receiving periodic reports from the ITSC and the Head of IT[394](index=394&type=chunk) - The company employs various measures to mitigate cybersecurity risks, including a Cybersecurity Incident Response Policy, access controls, encryption, systems monitoring, and the use of third-party experts for penetration testing and threat intelligence[389](index=389&type=chunk)[392](index=392&type=chunk) [Properties](index=78&type=section&id=Item%202.%20Properties) The company leases its principal executive office in Agoura Hills, California, and subleased its South San Francisco office in February 2025 - The principal executive office is located at 4149 Liberty Canyon Road, Agoura Hills, California, comprising 10,012 square feet of leased space[397](index=397&type=chunk) - In February 2025, the company subleased its former office space in South San Francisco to a third party through October 2027[397](index=397&type=chunk) [Legal Proceedings](index=78&type=section&id=Item%203.%20Legal%20Proceedings) The company is a defendant in a federal securities class action lawsuit filed in November 2023, alleging misleading disclosures about the izokibep trial - A purported federal securities class action lawsuit was filed against the company and its current and former officers and directors on November 15, 2023[398](index=398&type=chunk) - The complaint alleges misleading statements regarding the Phase 2b trial of izokibep in Hidradenitis Suppurativa (HS), with a motion to dismiss the amended complaint currently pending[398](index=398&type=chunk) - The company cannot reasonably estimate the potential loss from this lawsuit and has not accrued any liability[638](index=638&type=chunk) [Mine Safety Disclosures](index=79&type=section&id=Item%204.%20Mine%20Safety%20Disclosures) This item is not applicable to the company - Not applicable[401](index=401&type=chunk) Part II [Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities](index=80&type=section&id=Item%205.%20Market%20for%20Registrant%27s%20Common%20Equity%2C%20Related%20Stockholder%20Matters%20and%20Issuer%20Purchases%20of%20Equity%20Securities) ACELYRIN's common stock began trading on Nasdaq in May 2023, raising **$573.6 million** from its IPO, with no plans for future cash dividends - The company's common stock began trading on the Nasdaq Global Market under the symbol "SLRN" on May 5, 2023[404](index=404&type=chunk) - The company has never declared or paid cash dividends and does not plan to in the foreseeable future[406](index=406&type=chunk) - The IPO, which closed on May 9, 2023, generated net proceeds of approximately **$573.6 million** after deducting underwriting discounts and offering costs[408](index=408&type=chunk) [RESERVED](index=81&type=section&id=Item%206.%20%5BRESERVED%5D) This item is not applicable - Not applicable[411](index=411&type=chunk) [Management's Discussion and Analysis of Financial Condition and Results of Operations](index=81&type=section&id=Item%207.%20Management%27s%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) The company's net loss decreased to **$248.2 million** in 2024, driven by lower R&D expenses, with **$448.4 million** in cash deemed sufficient for the next 12 months [Results of Operations](index=88&type=section&id=Results%20of%20Operations) ACELYRIN's net loss decreased to **$248.2 million** in 2024, primarily due to a **$117.8 million** R&D expense reduction, offset by **$11.4 million** in restructuring charges Comparison of Results of Operations (in thousands) | | Year Ended December 31, | Change | | | :--- | :--- | :--- | :--- | :--- | | | **2024** | **2023** | **$** | **%** | | **Research and development** | $238,055 | $355,886 | $(117,831) | (33)% | | **General and administrative** | $66,809 | $66,178 | $631 | 1% | | **Restructuring charges** | $11,394 | $— | $11,394 | * | | **Total operating expenses** | $316,258 | $422,064 | $(105,806) | (25)% | | **Loss from operations** | $(316,258) | $(422,064) | $105,806 | (25)% | | **Net loss** | **$(248,226)** | **$(381,641)** | **$133,415** | **(35)%** | - The decrease in R&D expenses was primarily due to lower license fees and acquired in-process R&D, which in 2023 included **$123.1 million** for assets from the ValenzaBio acquisition and a **$15.0 million** milestone payment to Affibody, while 2024's main cost was a one-time **$31.0 million** payment to Pierre Fabre for an option buyout[450](index=450&type=chunk)[451](index=451&type=chunk) - Restructuring charges of **$11.4 million** were recognized in 2024, consisting of **$4.2 million** for employee severance and a net **$7.2 million** for contract cancellation costs related to the discontinuation of the izokibep program[458](index=458&type=chunk) [Liquidity, Capital Resources and Capital Requirements](index=91&type=section&id=Liquidity%2C%20Capital%20Resources%20and%20Capital%20Requirements) The company held **$448.4 million** in cash and marketable securities as of December 31, 2024, deemed sufficient for the next 12 months, despite increased net cash used in operations - As of December 31, 2024, the company had **$448.4 million** in cash, cash equivalents, restricted cash, and short-term marketable securities[461](index=461&type=chunk) - Management estimates that existing cash resources are sufficient to fund the operating plan and capital expenditure requirements for at least the next 12 months from the filing date of this report[461](index=461&type=chunk) Cash Flow Summary (in thousands) | | Year Ended December 31, | | | :--- | :--- | :--- | | | **2024** | **2023** | | **Net cash used in operating activities** | $(303,921) | $(169,705) | | **Net cash provided by (used in) investing activities** | $154,865 | $(447,744) | | **Net cash provided by financing activities** | $5,393 | $568,436 | - Non-cancellable purchase obligations under various contracts totaled **$21.5 million** as of December 31, 2024, a significant decrease from **$142.3 million** at the end of 2023[476](index=476&type=chunk)[477](index=477&type=chunk) [Financial Statements and Supplementary Data](index=98&type=section&id=Item%208.%20Financial%20Statements%20and%20Supplementary%20Data) This section presents the company's audited consolidated financial statements for 2023 and 2024, including balance sheets, statements of operations, and cash flows, with notes Consolidated Balance Sheet Data (in thousands) | | Dec 31, 2024 | Dec 31, 2023 | | :--- | :--- | :--- | | **Total Assets** | $491,141 | $742,690 | | **Total Liabilities** | $32,848 | $86,353 | | **Total Stockholders' Equity** | $458,293 | $656,337 | Consolidated Statement of Operations Data (in thousands) | | Year Ended Dec 31, 2024 | Year Ended Dec 31, 2023 | | :--- | :--- | :--- | | **Total operating expenses** | $316,258 | $422,064 | | **Loss from operations** | $(316,258) | $(422,064) | | **Net loss** | $(248,226) | $(381,641) | | **Net loss per share** | $(2.50) | $(5.43) | - The financial statements were audited by PricewaterhouseCoopers LLP, which issued an unqualified opinion[509](index=509&type=chunk) [Changes in and Disagreements With Accountants on Accounting and Financial Disclosures](index=135&type=section&id=Item%209.%20Changes%20in%20and%20Disagreements%20With%20Accountants%20on%20Accounting%20and%20Financial%20Disclosures) The company reports no changes in or disagreements with its accountants on accounting and financial disclosures - None[689](index=689&type=chunk) [Controls and Procedures](index=135&type=section&id=Item%209A.%20Controls%20and%20Procedures) Management concluded that disclosure controls and internal control over financial reporting were effective as of December 31, 2024, with no material changes - Management concluded that the company's disclosure controls and procedures were effective at a reasonable assurance level as of December 31, 2024[690](index=690&type=chunk) - Management concluded that the company's internal control over financial reporting was effective as of December 31, 2024[693](index=693&type=chunk) - As an emerging growth company, the annual report does not include an attestation report from the registered public accounting firm regarding internal control over financial reporting[694](index=694&type=chunk) [Other Information](index=135&type=section&id=Item%209B.%20Other%20Information) Effective March 19, 2025, CEO Mina Kim assumed the principal accounting officer role, and several executives terminated Rule 10b5-1 trading plans - Effective March 19, 2025, CEO Mina Kim also assumed the role of principal accounting officer[697](index=697&type=chunk) - Several executives, including the former CEO and the current Chief Medical Officer, terminated their prearranged Rule 10b5-1 trading plans between August 2024 and March 2025, with no shares sold under these plans prior to their termination[698](index=698&type=chunk)[699](index=699&type=chunk)[700](index=700&type=chunk)[701](index=701&type=chunk) Part III [Directors, Executive Officers and Corporate Governance](index=137&type=section&id=Item%2010.%20Directors%2C%20Executive%20Officers%20and%20Corporate%20Governance) The company's nine-member Board of Directors, with an independent Chair, oversees governance through three committees and adheres to a Code of Business Conduct - The Board of Directors consists of nine members, with a majority being independent, and Bruce C. Cozadd serves as the independent Chair of the Board[704](index=704&type=chunk)[716](index=716&type=chunk)[717](index=717&type=chunk) - The Board has three standing committees: Audit, Compensation, and Nominating and Corporate Governance, each composed of independent directors[724](index=724&type=chunk) - The company's executive officers as of March 19, 2025, are Mina Kim (CEO), Shephard Mpofu (Chief Medical Officer), and K. Amar Murugan (Chief Legal Officer)[748](index=748&type=chunk) - The company has adopted a Code of Business Conduct and Ethics and an Insider Trading Policy that includes prohibitions on hedging and pledging company stock[743](index=743&type=chunk)[745](index=745&type=chunk) [Executive Compensation](index=145&type=section&id=Item%2011.%20Executive%20Compensation) This section details executive compensation for 2023 and 2024, including base salary, bonuses, and equity awards, alongside severance and director compensation 2024 Summary Compensation for Named Executive Officers | Name | Position | Total Compensation ($) | | :--- | :--- | :--- | | **Mina Kim** | Chief Executive Officer | 5,659,331 | | **Shao-Lee Lin, M.D., Ph.D.** | Former Chief Executive Officer | 9,427,551 | | **Gil Labrucherie** | Chief Financial Officer & Chief Business Officer | 6,538,637 | | **Melanie Gloria** | Chief Operating Officer | 4,760,349 | | **Shephard Mpofu** | Chief Medical Officer | 2,529,666 | - The company has a Severance Plan providing cash payments, pro-rata target bonuses, continued health insurance premiums, and accelerated equity vesting for eligible executives upon qualifying termination events[773](index=773&type=chunk) - Non-employee directors receive an annual cash retainer of **$40,000**, additional retainers for chair and committee service, an initial option grant valued at **$600,000**, and an annual option grant valued at **$300,000**[789](index=789&type=chunk) [Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters](index=154&type=section&id=Item%2012.%20Security%20Ownership%20of%20Certain%20Beneficial%20Owners%20and%20Management%20and%20Related%20Stockholder%20Matters) This section details beneficial ownership of common stock as of February 28, 2025, with key holders including Westlake BioPartners (**9.7%**) and all directors/executive officers owning **10.8%** Security Ownership of 5% Beneficial Owners (as of Feb 28, 2025) | Name of Beneficial Owner | % of Common Stock | | :--- | :--- | | **Westlake BioPartners Fund II, L.P** | 9.7% | | **AyurMaya Capital Management Company, LP** | 9.3% | | **Tang Capital Management, LLC** | 7.3% | | **BlackRock, Inc.** | 6.0% | | **Access Industries Management, LLC** | 5.1% | - All current directors and executive officers as a group beneficially own **10.8%** of the company's common stock as of February 28, 2025[803](index=803&type=chunk) - As of December 31, 2024, a total of **8,043,529** securities remained available for future issuance under equity compensation plans approved by stockholders[797](index=797&type=chunk) [Certain Relationships and Related Transactions, and Director Independence](index=156&type=section&id=Item%2013.%20Certain%20Relationships%20and%20Related%20Transactions%2C%20and%20Director%20Independence) The company has a policy for reviewing related person transactions exceeding **$120,000** and indemnifies its directors and executive officers - The company has a formal written policy for identifying, reviewing, and approving related person transactions exceeding **$120,000**[810](index=810&type=chunk) - The company indemnifies its directors and executive officers and has entered into indemnification agreements with them[811](index=811&type=chunk)[812](index=812&type=chunk) [Principal Accounting Fees and Services](index=157&type=section&id=Item%2014.%20Principal%20Accounting%20Fees%20and%20Services) PricewaterhouseCoopers LLP served as the principal accountant, with total fees of **$1.762 million** in 2024 and **$3.532 million** in 2023, all pre-approved by the Audit Committee Accountant Fees (in thousands) | Fee Type | 2024 | 2023 | | :--- | :--- | :--- | | **Audit Fees** | $1,760 | $3,530 | | **All Other Fees** | $2 | $2 | | **Total Fees** | **$1,762** | **$3,532** | - All services provided by PricewaterhouseCoopers LLP were pre-approved by the Audit Committee, which has determined that the non-audit services are compatible with maintaining the accountant's independence[815](index=815&type=chunk)[816](index=816&type=chunk) Part IV [Exhibits, Financial Statement Schedules](index=158&type=section&id=Item%2015.%20Exhibits%2C%20Financial%20Statement%20Schedules) This section lists exhibits for the Annual Report on Form 10-K, including the Alumis merger agreement and key license contracts, with financial statement schedules omitted - The Agreement and Plan of Merger with Alumis Inc. is filed as Exhibit 2.1[819](index=819&type=chunk) - Material contracts, including the license and collaboration agreement with Affibody AB and the license and commercialization agreement with Pierre Fabre, are included as exhibits[820](index=820&type=chunk) - All financial statement schedules have been omitted because the required information is either not applicable or is included within the consolidated financial statements and notes[819](index=819&type=chunk)[822](index=822&type=chunk) [Form 10-K Summary](index=160&type=section&id=Item%2016.%20Form%2010-K%20Summary) The company has not provided a summary for Form 10-K - None[823](index=823&type=chunk)

Core Points - ACELYRIN, INC. has adopted a limited-duration stockholder rights plan in response to Tang Capital Partners accumulating 8.8% of its outstanding common stock [1][3] - The rights plan aims to maximize stockholder value and is effective immediately, expiring on March 12, 2026 [2][4] Rights Plan Details - Each share of common stock will receive one right, which will become exercisable if any person acquires 10% or more of the company's outstanding common stock [3] - Holders of rights (excluding the acquiring person) can purchase additional shares at a price equal to twice the exercise price [3] - Current owners exceeding the Triggering Percentage can retain their shares but cannot acquire more without triggering the rights plan [3] Company Overview - ACELYRIN focuses on developing transformative medicines in immunology, with its lead program being lonigutamab, a monoclonal antibody for thyroid eye disease [5]

Core Viewpoint - The merger between Alumis Inc. and ACELYRIN, INC. aims to create a leading clinical-stage biopharma company focused on immune-mediated diseases, enhancing long-term value for shareholders through a diversified late-stage portfolio and strong financial position [1][2][5]. Company Overview - Alumis is a clinical-stage biopharmaceutical company developing oral therapies for immune-mediated diseases, utilizing a precision data analytics platform to optimize clinical outcomes [6]. - ACELYRIN focuses on providing transformative medicines and is currently developing lonigutamab for thyroid eye disease [7]. Merger Details - The all-stock transaction is expected to close in the second quarter of 2025, pending stockholder approval and customary closing conditions [3]. - The combined company will have a pro forma cash position of approximately $737 million as of December 31, 2024, allowing for the advancement of its pipeline and operational needs into 2027 [5]. Strategic Benefits - The merger will create a diversified portfolio of late-stage clinical assets targeting large, established markets, including therapies for plaque psoriasis, systemic lupus erythematosus, and multiple sclerosis [5]. - The combined company is expected to leverage increased financial flexibility and resources to develop life-changing medicines and enhance commercial capabilities [5]. Leadership and Governance - The executive leadership teams of both companies have a proven track record in public company management and value creation, positioning the combined entity for success [5]. - The ACELYRIN Board of Directors supports the merger, believing it maximizes long-term value for its stockholders [2]. Financial Advisors - Morgan Stanley & Co. LLC is serving as financial advisor to Alumis, while Guggenheim Securities, LLC is advising ACELYRIN [4].