ANAB 10-K & 10-Q changes, risk factors and insider trading

•Our product candidates in development may fail or suffer delays that adversely affect their commercial viability. Results from our initial clinical trials may not be representative of the results we will experience in later clinical trials. If we or our collaborators are unable to complete development of or commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

•Our ongoing and planned clinical trials or those of our collaborators may reveal significant adverse events, toxicities or other side effects and may result in a safety profile that could inhibit regulatory approval or market acceptance of any of our product candidates.

•We and/or our collaborators may be unable to obtain, or may be delayed in obtaining, required regulatory approvals in the United States or in foreign jurisdictions, which would materially impair our ability to commercialize and generate revenue from our product candidates.

•Even if our product candidates receive regulatory approval, they will be subject to significant post-marketing regulatory requirements.

•We may not be successful in our efforts to expand our pipeline of product candidates and develop marketable products.

•We are currentlyassessing inadvancement to Phase 23 of clinical development of rosnilimab,rosnilimab for RA, and have no history of commercializing biotechnology products, which may make it difficult to evaluate the prospects for our future viability.

•We face significant competition, and if our competitors develop and market products that are more effective, safer or less expensive than our product candidates, our commercial opportunities will be negatively impacted.

•Our product candidates may not achieve adequate market acceptance among physicians, patients, health care payors and others in the medical community necessary for commercial success.

•We currently have no marketing and sales force. If we are unable to establish effective sales or marketing capabilities or enter into agreements with third parties to sell or market our product candidates, we may not be able to effectively sell or market our product candidates, if approved, or generate product revenue.

•The manufacture of biologics is complex, and our third party manufacturers may encounter difficulties in production. If any of our third party manufacturers encounter such difficulties, our ability to provide supply of our product candidates for clinical trials, our ability to obtain marketing approval, or our ability to provide supply of our products for patients, if approved, could be delayed or stopped.

•Political, economic or public health events may have a material impact on the U.S. and global economies and could have a material adverse impact on our employees, contractors and patients, which could adversely and materially impact our business, financial condition and results of operations.

•We have limited operating revenue and a history of operational losses and may not achieve or sustain profitability.

•We have no products approved for commercial sale, and to date we have not generated any revenue or profit from sales of our product candidates.

•We will require additional capital to finance our operations, which may not be available to us on acceptable terms, or at all. As a result, we may not complete the development and commercialization of our product candidates or develop new product candidates.

•Our existing collaboration with GSK and other collaborations are important to our business, and other future collaborations may also be important to us. If we are unable to maintain the GSK collaboration, or if this collaboration is not successful, our business could be adversely affected.

•We may not succeed in establishing and maintaining additional development and commercialization collaborations, which could adversely affect our ability to develop and commercialize product candidates.

•If we are unable to obtain or protect intellectual property rights in the U.S. and throughout the world, we may not be able to compete effectively in our market.

•We must attract and retain highly skilled employees in order to succeed.

•The market price of our stock has been and may continue to be volatile, and you could lose all or part of your investment.

A product candidate can unexpectedly fail at any stage of preclinical and clinical development. The historical failure rate for product candidates is high due to scientific feasibility, safety, efficacy, changing standards of medical care, and other variables. The results from preclinical testing or early clinical trials of a product candidate may not predict the results that will be obtained in later phase clinical trials of the product candidate. For example, in February 2025 we reported interim positive results for rosnilimab’s Phase 2b clinical trial in rheumatoid arthritis. However, the results we have received to date may not be predictive of the full, complete clinical trial results.

Furthermore, we may conduct clinical trials of a product candidate in multiple indications based on assumptions about the product candidate’s mechanism of action. However, it is possible that our assumptions regarding the effectiveness of a product candidate’s mechanism of action may be incorrect and that the product candidate may be ineffective in certain diseases or disorders. If this were the case, then the results from any clinical trials of a product candidate that we conduct are less likely to be positive. For example, even though we showed interim positive data for rosnilimab in our Phase 2b clinical trial in rheumatoid arthritis, data from rosnilimab’s ongoing Phase 2 clinical trial in ulcerative colitis maywas not be positive.

•obtaining regulatory permission to initiate clinical trials;

•successful enrollment of patients in, and the completion of, our planned clinical trials;

•receiving marketing approvals from applicable regulatory authorities;

•establishing commercial manufacturing capabilities and/or making arrangements with third party manufacturers;

•obtaining and maintaining patent and trade secret protection and non-patent exclusivity for our product candidates and their components;

•enforcing and defending intellectual property rights and claims;

•achieving desirable therapeutic properties for our product candidates’ intended indications;

•launching commercial sales of our product candidates, if and when approved, whether alone or in collaboration with third parties;

•acceptance of our product candidates, if and when approved, by patients, the medical community and third party payors;

•effectively competing with other therapies; and maintaining an acceptable safety profile of our product candidates through clinical trials and following regulatory approval.

•imposition of a clinical hold for safety reasons or following an inspection of clinical trial operations or site by the FDA or other regulatory authorities;

•manufacturing challenges;

•insufficient supply or quality of product candidates or other materials necessary to conduct clinical trials;

•delays in reaching or failure to reach agreement on acceptable clinical trial contracts or clinical trial protocols with prospective trial sites and CROs or failure by such CROs or trials sites to carry out the clinical trial in accordance with our agreed-upon terms;

•non-clinical or clinical sites becoming unavailable due to political, economic, or public health events;

•clinical sites electing to terminate their participation in one of our clinical trials;

•inability or unwillingness of patients or medical investigators to follow clinical trial protocols;

•required clinical trial administrative actions;

•slower than anticipated patient enrollment;

•changing standards of care;

•safety concerns;

•availability or prevalence of use of a comparative drug or required prior therapy; or clinical outcomes or financial constraints.

•be delayed in obtaining marketing approval for our product candidates;

•not obtain marketing approval at all;

•obtain marketing approval in some countries and not in others;

•obtain approval for indications or patient populations that are not as broad as intended or desired;

•obtain approval with labeling that includes significant use or distribution restrictions or safety warnings, including boxed warnings;

•be subject to additional post-marketing testing requirements; or have the product removed from the market after obtaining marketing approval.

Any regulatory approvals that we or our collaborators may receive for our product candidates will require surveillance to monitor the safety and efficacy of the product candidate, may contain significant limitations related to use restrictions for specified age groups, warnings, precautions or contraindications, and may include burdensome post-approval study or risk management requirements. For example, the FDA may require a risk evaluation and mitigation strategy in order to approve our product candidates, which could entail requirements for a medication guide, physician communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. In addition, if the FDA or foreign regulatory authorities approve our product candidates, the manufacturing processes, labeling, packaging, distribution, adverse event reporting, storage, advertising, promotion, import, export and recordkeeping for our product candidates will be subject to extensive and ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, registration, as well as continued compliance with cGMPscGMP regulations and good clinical practices for any clinical trials that we conduct post-approval. In addition, manufacturers of drug products and their facilities are subject to continual review and periodic inspections by the FDA and other regulatory authorities for compliance with cGMP regulations and standards. If we, our collaborators or a regulatory agency discover previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facilities where the product is manufactured, a regulatory agency may impose restrictions on that product, the manufacturing facility or us or our collaborators, including requiring recall or withdrawal of the product from the market or suspension of manufacturing. In addition, failure to comply with FDA and foreign regulatory requirements may, either before or after product approval, if any, subject our company or our collaborators to administrative or judicially imposed sanctions, including:

•restrictions on our ability to conduct clinical trials, including full or partial clinical holds on ongoing or planned trials;

•restrictions on the products, manufacturers or manufacturing process;

•warning or untitled letters;

•civil and criminal penalties;

•injunctions;

•suspension or withdrawal of regulatory approvals;

We are a clinical-stage biotechnology company focused on delivering innovative immunology therapeutics for autoimmune and inflammatory diseases. Our clinical-stage pipeline includes our lead program, rosnilimab, a depleterselective and agonist targeting PD-1+pathogenic T cells,cell indepleter, for which we completed a Phase 2b trial for the treatment of moderate-to-severe rheumatoid arthritis (“RA”) and a Phase 2 trial for the treatment of moderate-to-severe ulcerative colitis (“UC”). We also have other antibodies in our portfolio, including, ANB033, a CD122 antagonistantagonist, in a Phase 11b trial for celiac disease (“CeD”) and eosinophilic esophagitis (“EoE”), and ANB101, a BDCA2 modulator, enteringin a Phase 11a trial. We have also discovered and out-licensed, in financial collaborations, multiple therapeutic antibodies licensed to GlaxoSmithKline, Inc. (“GSK”) in a financial collaboration for immuno-oncology,antibodies, including a PD-1 antagonist (Jemperli (dostarlimab-gxly) or “Jemperli”) to GSK and aan TIM-3IL-36R antagonist (cobolimab,imsidolimab) GSK4069889to Vanda Pharmaceuticals Inc. (“Vanda”). We currently recognize revenue from milestones and royalties achieved under our immuno-oncology collaboration with GSK.GSK and license and transition services revenue from our collaboration with Vanda.

Our Wholly Owned Product CandidateClinical-Stage Pipeline

Our immuneantibodies cellare modulatingin antibodiesdevelopment to treat inflammatory disorders by down regulating immune responses mediated by multiple immune cell types including T cells.diseases. We believe these molecules have potential applicability across a broad range of autoimmune and inflammatory diseasesdiseases, including dermatology,in gastroenterology, rheumatology, gastroenterology,dermatology, respiratory, and neurologyother therapeutic areas.

Rosnilimab is an IgG1 antibody that directly targets pathogenic T cells, such as activated Tph/Tfh and T effector cells, in the periphery or inflamed tissue. These T cells, when activated, proliferate and migrate, and secrete the inflammatory cytokines that are the drivers of autoimmune and inflammatory diseases. Rosnilimab is designed to selectively deplete pathogenic T cells in both inflamed tissue and the periphery while sparing non-pathogenic T cells, including naïve T cells, to preserve overall immune function and restore immune homeostasis. This drives specific immunological outcomes, such as a reduction in T cell proliferation, migration and cytokine secretion, and a reduction of plasma cell generation and autoantibody levels. We announced positive top-line data from a healthy volunteer Phase 1 trial of rosnilimab in November 2021.2021 that supported advancement of rosnilimab into subsequent patient trials. A total of 144 subjects were enrolled in the randomized, double-blind, placebo-controlled healthy volunteer Phase 1 trial, where single ascending dose (“SAD”) cohorts received subcutaneous (“SC”) or intravenous (“IV”) single doses of rosnilimab up to 600mg or placebo, while multiple ascending dose (“MAD”) cohorts received four weekly subcutaneous doses of rosnilimab ranging up to 400mg or placebo. Rosnilimab was generally well-tolerated and no dose limitingdose-limiting toxicities were observed. Rosnilimab demonstrated a sustained systemic exposure and dose-proportionality with an estimated two-week half-life for subcutaneous and IV routes of administration.

In February 2025, we announced top-lineinitial datadata, which was subsequently updated in June 2025, from rosnilimab’s randomized, placebo-controlled, global 424-patient, Phase 2b clinical trial for moderate-to-severe rheumatoid arthritis. Patients were randomized to receive either 100mg of subcutaneous rosnilimab every four weeks (Q4W), 400mg Q4W, 600mg every two weeks (Q2W),weeks, or placebo. The trial achieved its primary endpoint of the mean change from baseline in baseline disease activity score -- 28 joints (DAS-28) C-Reactive Protein (CRP) score at Week 12 for all three doses of rosnilimab compared to the placebo.

ANB033 targetsis an antagonist of CD122, the common beta subunit shared by the IL-15 and IL-2 receptors. IL-15 and IL-2 signaling mediate the proliferation and survival of NKsubsets cellsof CD8+ and certain CD8CD4 T+ cellcells, subsets.NK cells, as well as ILC2s. ANB033 is an antibody designed with an optimal epitope and affinity to CD122 that inhibits IL-15 and IL-2 signaling through both the lowintermediate affinity IL-2 receptor (comprised of CD122 and the common gamma subunit, CD132) while sparing IL-2 signaling throughand the high affinity IL-2 receptor (comprised of CD122, CD132 and the alpha receptor subunit for IL-2, CD25) expressed by regulatoryactivated CD4 Th1 and Th2 T cells.cells Thisas leadswell toas ILC2. Antagonizing CD122 has the potential to achieve and maintain remission of inflammation through the reduction of disease-causing NK cells and certaincytolytic CD8 T cell subsets, whileincluding sparingintraepithelial regulatorylymphocytes, TNK cells.cells Byand preventingreducing theinflammatory consumptioncytokine of IL-2secretion by pathogenicactivated cellsCD4+ thatTh1 expressand theTh2 lowcells, affinityas IL-2well receptor,as circulatingILC2 levels of IL-2 may increase, potentially enhancing regulatory T cell numbers that express the high affinity IL-2 receptor in the setting of inflammation. We initiated a Phase 1 clinical trial of ANB033 in October 2024.cells.

BloodANB101 is a blood dendritic cell antigen 2 (“BDCA2”) modulator antibody that targets plasmacytoid dendritic cells (“pDCs”) and inhibits interferon secretion and modulates antigen presentation for the treatment of autoimmune and inflammatory diseases. BDCA2 is a molecule specifically expressed on plasmacytoid dendritic cells (“pDCs”),pDCs, a class of immune cells which, while found in relatively small numbers in healthy individuals, are enriched in patients with a variety of inflammatory diseases, that is critical to the regulation of toll-like receptor signaling and interferon secretion. pDCs are a key upstream node in the inflammatory cascade that serve as a bridge between innate and adaptive immunity. They have been shown to be prolific secretors of type I interferons, which drive activation of a variety of downstream cell types including T cells and monocytes. Together with their ability to present antigens to the adaptive immune system, this creates a pro-inflammatory environment for the establishment and perpetuation of autoimmune pathology. BDCA2 has been implicated in the pathophysiology of systemic lupus erythematosus (“SLE”), where there exists mechanistic clinical proof of concept for pDC modulation. ANB101 is a BDCA2 modulator antibody that targets pDCs and potently inhibits interferon secretion and modulates antigen presentation for the treatment of autoimmune and inflammatory diseases. We plan to initiate enrollment for a Phase 1 clinical trial in the first quarter of 2025.

Under the GSK Agreement, a Biologics License Application (“BLA”) for our most advanced partnered program, which is a PD-1 antagonist antibody called Jemperli (dostarlimab), was approved by the FDA in April 2021 for the treatment of advanced or recurrent deficient mismatch repair endometrial cancer (“dMMREC”). In February 2023, the FDA granted full approval for this indication (from an accelerated approval). In addition, in April 20212021, the European Medicines Agency (“EMA”) granted conditional marketing authorization in the European Union (“EU”) for Jemperli for use in women with mismatch repair deficient (“dMMR”)/microsatellite instability-high (“MSI-H”) recurrent or advanced endometrial cancer who have progressed on or following prior treatment with a platinum containing regimen. A second FDA approval was received in August 2021 for Jemperli in pan-deficient mismatch repair tumors (PdMMRT). In July 2023, the FDA approved Jemperli in combination with chemotherapy for the treatment of adult patients with dMMR MSI-H primary advanced or recurrent endometrial cancer. In December 2023, the EMA approved, in the EU,approved Jemperli plus chemotherapy for dMMR/MSI-H primary advanced or recurrent endometrial cancer. In August 2024, the FDA approved Jemperli plus chemotherapy for all adult patients with primary advanced or recurrent endometrial cancer. In January 2025, the EMA approved Jemperli plus chemotherapy for this same indication. In October 2025, GSK terminated the TIM-3 antagonist antibody development program under our existing collaboration, and all rights to the TIM-3 antagonist antibody will be reverted to us in the near future.

For the year ended December 31, 2024,2025, GSK reported $598.0$1.1 millionbillion in sales for Jemperli, a greater than 200%80% sales growth when compared to $175.6$598.0 million for the year ended December 31, 2023.2024.

Vanda Pharmaceuticals Collaboration

On January 31, 2025, we entered into an Exclusive License Agreement (the “Vanda License Agreement”) with Vanda Pharmaceuticals Inc. (“Vanda”) pursuant to which we granted to Vanda an exclusive, global license for the development and commercialization of imsidolimab (IL-36R antagonist mAb), which has completed two registration-enabling global Phase 3 trials, GEMINI-1 and GEMINI-2, evaluating the safety and efficacy of imsidolimab in patients with Generalizedgeneralized Pustularpustular Psoriasispsoriasis (“GPP”).

Pursuant to the terms of the Vanda License Agreement, we will receivereceived an upfront payment of $10.0 million and a $5.0 million payment for existing drug supply. AnaptysWe isare also eligible to receive up to $35.0 million for future regulatory approval and sales milestones in addition to a 10% royalty on net sales.sales, as well as the following milestones under the Vanda License Agreement:

In March 2014, we entered into a Collaboration and Exclusive License Agreement (the “GSK Agreement”) with TESARO, Inc. (“Tesaro”), an oncology-focused biopharmaceutical company now a part of GSK (Tesaro and GSK are hereinafter referred to, collectively, as “GSK”). Currently, under the GSK Agreement, GSK is developing Jemperli (dostarlimab) as a monotherapy and in combination with additional therapies, for various solid tumor indications. In addition, GSK is developing dostarlimab in combination with additional therapies under the collaboration, including with another development program from the GSK Agreement: cobolimab, a TIM-3 antibody, in 2L NSCLC. In October 2023, Amendment No. 5 to the GSK Agreement (the “GSK Amendment No. 5”) was agreed by both parties to terminate the LAG-3 antagonist antibody development program under the GSK Agreement. In accordance with the GSK Agreement and the GSK Amendment No. 5, we have regained full global rights to the LAG-3 antagonist antibody development program.

For eachJemperli, the remaining development program under the GSK Agreement, we are eligible to receive milestone payments if certain preclinical and clinical trial events are achieved by GSK, if certain U.S. anda European regulatory submissionssubmission and approvalsapproval in multiplea indicationssecond areindication achieved,is and upon the achievement of specified levels of annual worldwide net sales. We will also be eligible to receive tiered 4-8% royalties related to worldwide net sales of products developed under the collaboration.achieved. On October 23, 2020, Amendment No. 3 to the GSK Agreement (the “GSK Amendment No. 3”) was agreed to by both parties to permit GSK to conduct development and commercialization in combination with any third party molecules of Zejula, an oral, once-daily poly (ADP-ribose) polymerase (PARP) inhibitor (“Zejula”). Under GSK Amendment No. 3, we were granted increased royalties upon sales of Jemperli, equal to 8% of Netnet Salessales (as defined in the GSK Agreement) below $1.0 billion, 12% of Netnet Salessales between $1.0 billion and $1.5 billion, 20% of Netnet Salessales between $1.5 billion and $2.5 billion and 25% of Netnet Salessales above $2.5 billion. Unless earlier terminated by either party upon specified circumstances, the GSK Agreement will terminate, with respect to each specific developed product, upon the later of the 12th anniversary of the first commercial sale of the product or the expiration of the last to expire of any patent.

In October 2021, we signed a royalty monetization agreement (“Jemperli Royalty Monetization Agreement”) with Sagard Healthcare Royalty Partners, LP (“Sagard”). Under the terms of the Jemperli Royalty Monetization Agreement, we received $250.0 million in exchange for royalties and milestones payable to us under our GSK collaboration on annual global net sales of Jemperli. We retained the rights to a $75.0 million sales milestone when Jemperli annual Net Sales exceed $1 billion.

In May 2024, we entered into an amendment to the Jemperli Royalty Monetization Agreement, Amendment No. 1 (the “Jemperli Amendment”) under which we sold additional receivables to Sagard in exchange for $50.0 million. The Jemperli Amendment includes all Jemperli sales, including any product containing Jemperli, whether or not such product constitutes a combination product, and the threshold amounts of aggregate Jemperli royalties and milestones to be received by Sagard under the Jemperli Amendment is either $600.0 million if received by the end of March 31, 2031, or $675.0 million if received thereafter. Once either of these thresholds are met, the Jemperli Royalty Monetization Agreement and the Jemperli Amendment will expire, resulting in us regaining all subsequent Jemperli royalties and milestones. As of JanuaryDecember 31, 2025, Sagard has receivedaccrued aapproximately total of $88.8$250.0 million in royalties and milestones. For more information see Note 5 — Sale of Future Royalties in the accompanying notes to the consolidated financial statements included in Part II, Item 8, “Consolidated Financial Statements and Supplementary Data” of this Annual Report on Form 10-K.

(1)Biologics License Application (“BLA”) (2)Marketing Authorization Application (“MAA”) (3)For Jemperli, the filing and approval of the first MAA for a second indication and first three commercial sales milestones are included as part of the royalty monetization agreement with Sagard,Sagard. For more information, see Note 5.

(4)For Jemperli, we retained the rights to a $75.0 million sales milestone when Jemperli annual Netnet Salessales exceedexceeded $1 billion. We received the cash milestone payment in December 2025.

In connection with the 2020 Amendment, in October 2020 GSK agreed, under the terms of a settlement agreement (the “GSK Settlement Agreement”), to pay us a royalty on all GSK net sales of Zejula starting January 1, 2021. Under the GSK Settlement Agreement, the royalty is paid at a rate of 1% but is subject to reduction due to royalties paid to third parties, with a minimum royalty payable under the GSK Settlement Agreement of 0.5% of global net sales of Zejula. The current effective royalty rate is 0.5%. In September 2022, we signed a royalty monetization agreement (the “Zejula Royalty Monetization Agreement”) with a wholly owned subsidiary of DRI Healthcare Trust (“DRI”) to monetize all of our future royalties on global net sales of Zejula under the GSK Settlement Agreement. Under the terms of the Zejula Royalty Monetization Agreement, we received $35.0 million in exchange for all royalties payable by GSK to us under the GSK Settlement Agreement on global net sales of Zejula starting in July 2022. In addition, under the Zejula Royalty Monetization Agreement, we are entitled to receive an additional $10.0 million payment from DRI if Zejula is approved by the FDA for the treatment of endometrial cancer on or prior to December 31, 2025.

Research and development expenses consist of costs associated with our research and development activities, including drug discovery efforts, preclinical and clinical development of our programs, and manufacturing. Our research and development expenses include:

•External research and development expenses incurred under arrangements with third parties, such as contract research organizations (“CROs”), consultants, members of our scientific and therapeutic advisory boards, and contract manufacturing organizations (“CMOs”);

•Employee-related expenses, including salaries, benefits, travel, and stock-based compensation;

•Facilities, depreciation and other allocated expenses, which include direct and allocated expenses for rent and maintenance of facilities, depreciation of leasehold improvements and equipment, and laboratory supplies; and License and sub-license fees.

We are conducting research and development activities primarily on inflammation programs. We have a research and development team that conducts antibody discovery, characterization, translational studies, IND-enabling preclinical studies, and clinical development. We conduct some of our early research and preclinical activities internally and plan to rely on third parties, such as CROs and CMOs, for the execution of certain of our research and development activities, such as in vivo toxicology and pharmacology studies, drug product manufacturing, and clinical trials.

Investing in our common stock involves a high degree of risk. You should carefully consider the risks described below, as well as the other information in this Quarterly Report,report, including our consolidated financial statements and the related notes and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” before deciding whether to invest in our common stock. The occurrence of any of the events or developments described below could harm our business, financial condition, results of operations, and growth prospects. In such an event, the market price of our common stock could decline, and you may lose all or part of your investment.

•Our existing collaboration with GSK and other collaborations are important to our business, and other future collaborations may also be important to us.business. If we are unable to maintain the GSK collaboration, or if this collaboration is not successful, our business could be adversely affected.

•If we are unable to obtain or protect intellectual property rights in the U.S. and throughout the world,rights, we may not be able to compete effectively in our market.

•The market price of our stock has been and may continue to be volatile, and you could lose all or part of your investment.

You should read the following discussion and analysis of our financial condition and results of operations together with our unaudited consolidated financial statements and related notes for the ninethree months ended SeptemberMarch 30,31, 2025,2026, included in Part I, Item 1 of this Quarterly Reportreport and with our audited consolidated financial statements and related notes thereto for the year ended December 31, 20242025 included in our Annual Report on Form 10-K. This discussion and other sections of this Quarterly Report contain forward-looking statements that involve risks and uncertainties, such as our plans, objectives, expectations, intentions, and beliefs. Our actual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those identified below and those discussed in the section entitled “Risk Factors” included in Part II, Item 1A of this Quarterly Report. You should also carefully read “Special Note Regarding Forward-Looking Statements.Statements”.

WePrior areto the separation described below, we were a clinical-stage biotechnology company focused on delivering innovative immunology therapeutics for autoimmune and inflammatory diseases. Our clinical-stage pipeline includes our lead program,included rosnilimab, a selective and potent pathogenic T cell depleter, thatfor which we completed a Phase 2b trial for the treatment of moderate-to-severe rheumatoid arthritis (“RA”) and is in a Phase 2 trial for the treatment of moderate-to-severe ulcerative colitis (“UC”). Our pipeline also includes, ANB033, a CD122 antagonist, in a Phase 1b trial for celiac disease (“CeD”) and eosinophilic esophagitis (“EoE”), and ANB101, a BDCA2 modulator, in a Phase 1a trial. Anaptys hasWe also discovered and out-licensedout-licensed, in financial collaborationscollaborations, multiple therapeutic antibodies, including a PD-1 antagonist (Jemperli (dostarlimab-gxly) or “Jemperli”) to GSK and an IL-36R antagonist (imsidolimab) to Vanda Pharmaceuticals Inc. (“Vanda”). We currently recognize revenue from milestones and royalties achieved under our immuno-oncology collaboration with GSK and license and transition services revenue from our collaboration with Vanda.

In September 2025, we announced that our board of directors (“Board of Directors”) approved plans to explore separating our business into two independent, publicly traded companies. OneWe company is expected towould hold and continue to manage the financial collaboration for Jemperli milestones and royalties fromwith GSK and thefor milestonesimsidolimab andwith royalties from VandaVanda, with a focus on protecting and returning value of the royalties to its shareholders.stockholders. The otherspun-out company is expected towould be a clinical-stage biotechnology company focused on the development and potential commercialization of innovative therapeutics for autoimmune and inflammatory diseases, including rosnilimab, ANB033 and ANB101. UponThis completionseparation of the separation, which is expected to bewas completed by year-end 2026, we intend to launch the biotechnology company with adequate capital to fund operations for at least two years. While the separation is anticipated to be a taxable event, we are focused on minimizingApril overall20, corporate and shareholder-level taxes across the entire transaction. Completion of the proposed separation is subject to final approval by our Board of Directors and other customary conditions, including the effectiveness of a registration statement with the Securities and Exchange Commission (the “SEC”).2026.

Under the GSK Agreement, a Biologics License Application (“BLA”) for ourJemperli most advanced partnered program, which is(dostarlimab), a PD-1 antagonist antibody called Jemperli (dostarlimab),antibody, was approved by the FDA in April 2021 for the treatment of advanced or recurrent deficient mismatch repair endometrial cancer (“dMMREC”). In February 2023, the FDA granted full approval for this indication (from an accelerated approval).indication. In addition, in April 2021, the European Medicines Agency (“EMA”) granted conditional marketing authorization in the European Union (“EU”) for Jemperli for use in women with mismatch repair deficient (“dMMR”)/microsatellite instability-high (“MSI-H”) recurrent or advanced endometrial cancer who have progressed on or following prior treatment with a platinum containing regimen. A second FDA approval was received in August 2021 for Jemperli in pan-deficient mismatch repair tumors (PdMMRT). In July 2023, the FDA approved Jemperli in combination with chemotherapy for the treatment of adult patients with dMMR MSI-H primary advanced or recurrent endometrial cancer. In December 2023, the EMA approved, in the EU,approved Jemperli plus chemotherapy for dMMR/MSI-H primary advanced or recurrent endometrial cancer. In August 2024, the FDA approved Jemperli plus chemotherapy for all adult patients with primary advanced or recurrent endometrial cancer. In January 2025, the EMA approved Jemperli plus chemotherapy for this same indication. In October 2025, GSK terminated the TIM-3 antagonist antibody development program under our existing collaboration, and all rights to the TIM-3 antagonist antibody will be reverted to us in the near future.

Pursuant to the terms of the Vanda License Agreement, we received an upfront payment of $10.0 million and a $5.0 million payment for existing drug supply. We are also eligible to receive a 10% royalty on net sales, as well as the following milestonessales under the Vanda License Agreement:

The Separation and Distribution Agreement provides that any and all rights to receive milestone payments under the Vanda License Agreement will be allocated to First Tracks Biotherapeutics. For more information about these collaborations, see Note 4 — Collaborative Research and Development Agreements in the accompanying notes to the consolidated financial statements.

We have not generated any revenue from product sales. Our revenue has been derived from amortization of upfront license payments, research and development funding, milestone and royalty payments under collaboration and license agreements with our collaborators. From inception through SeptemberMarch 30,31, 2025,2026, we have recognized $472.9$606.7 million in revenue from our collaborators. We have not generated any revenue from product sales.

Research and development expenses consist of costs associated with our research and development activities, including drug discovery efforts, preclinical and clinical development of our programs, and manufacturing. Our research and development expenses includeincluded:

•External research and development expenses incurred under arrangements with third parties, such as contract research organizations (“CROs”), consultants, members of our scientific and therapeutic advisory boards, and contract manufacturing organizations (“CMOs”);

•Employee-related expenses, including salaries, benefits, travel, and stock-based compensation;

•Facilities, depreciation and other allocated expenses, which include direct and allocated expenses for rent and maintenance of facilities, depreciation of leasehold improvements and equipment, and laboratory supplies; and License and sub-license fees.

We are conducting research and development activities primarily on inflammation programs. We have a research and development team that conducts antibody discovery, characterization, translational studies, IND-enabling preclinical studies, and clinical development. We conduct some of our early research and preclinical activities internally and plan to rely on third parties, such as CROs and CMOs, for the execution of certain of our research and development activities, such as in vivo toxicology and pharmacology studies, drug product manufacturing, and clinical trials.

Our management’s discussion and analysis of our financial condition and results of operations are based on our financial statements, which have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The preparation of these financial statements requires us to make judgments and estimates that affect the reported amounts of assets, liabilities, revenues, and expenses and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events, and various other factors that are believed to be reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions. On an ongoing basis, we evaluate our judgments and estimates in light of changes in circumstances, facts, and experience. We believe there have been no significant changes in our critical accounting policies as discussed in our Annual Report on Form 10-K filed with the SEC on FebruaryMarch 27,3, 2025.2026.

Results of Operations –- Comparison of the Three and Nine Months Ended SeptemberMarch 30,31, 20252026 and 20242025

Collaboration revenue consists of milestone payments, royalty payments, upfront license fees and transition services provided under our collaboration agreements. We recognized a $50.0 millionno milestone revenue during each of the three and nine months ended SeptemberMarch 30,31, 2025 when Jemperli annual sales exceeded $750 million. Our first sales milestone for $15.0 million was recognized during the three2026 and nine months ended September 30, 2024 when Jemperli annual sales exceeded $250 million. These milestone revenues are Jemperli non-cash revenue related to the Jemperli Royalty Monetization Agreement.2025. We expect that any collaboration revenue we generate will continue to fluctuate from period to period as a result of the timing and amount of milestones from our existing collaborations.

Royalty revenue is a function of our partners’ product sales and the applicable royalty rate. During the three months ended SeptemberMarch 30,31, 20252026 and 2024,2025, we recognized $26.3$25.5 million and $15.0 million, respectively, of royalty revenue related to the net sales of GSK’s Jemperli and Zejula. During the nine months ended September 30, 2025 and 2024, we recognized $66.6 million and $33.2$18.1 million, respectively, of royalty revenue related to the net sales of GSK’s Jemperli and Zejula. All royalty revenue recognized for the three and nine months ended SeptemberMarch 30,31, 20252026 and 20242025 is non-cash revenue pursuant to the Royalty Monetization Agreements. For more informationinformation, see Note 5 — Sale of Future Royalties in the accompanying notes to the consolidated financial statements. During the three months ended March 31, 2026 and 2025, we recognized $0.0 million and $9.6 million, respectively, of license revenue under ASC 606.

During the nine months ended September 30, 2025, we recognized $9.6 million of license revenue under ASC 606 and recognized no license revenue under ASC 606 during the three months ended SeptemberMarch 30,31, 2025. During the three2026 and nine months ended September 30, 2025, we recognized less than $0.1 million and $0.2$0.1 million, respectively, related to transition services provided under our Vanda License Agreement. No revenue was recognized under this agreement during the three and nine months ended September 30, 2024.

Research and development expenses were $31.4$34.0 million during the three months ended SeptemberMarch 30,31, 20252026 compared to $42.2$41.2 million during the three months ended SeptemberMarch 30,31, 20242025, for a decrease of $10.8$7.2 million, primarily due to a $8.3$7.8 million decrease in clinical expenses, $3.1$0.2 million decrease in outside services for manufacturing expenses, $0.9 million decrease in other research and development expenses, offset by a $0.5$1.5 million increase in salaries and related expenses, $0.1 million increase in stock-based compensation expense, and $0.1 million increase in salariesrecruiting and related expenses.costs.

General and administrative expenses were $10.2$26.2 million during the three months ended SeptemberMarch 30,31, 20252026 compared to $10.6$14.1 million during the three months ended SeptemberMarch 30,31, 20242025, for aan decreaseincrease of $0.4approximately million,$12.1 million. The increase is primarily due to aan $0.5$8.3 million decreaseincrease in marketlegal research,expenses due to the GSK lawsuit and $0.5activity related to the separation of the business, a $4.9 million decreaseincrease in stock compensation expense, a $0.7 million increase in personnel costs, offset by $0.5 million increase in stock-based compensation, and a $0.1$0.8 million net increase in other general and administrative expenses.expenses, offset by a $2.5 million decrease in transaction costs related to our Vanda License Agreement, and a $0.1 million decrease in market research costs.

We expect that our general and administrative expenses will increasedecrease for the foreseeable future as we incurexperience costsfewer expenses associated with beingsalaries aand publiclyrelated traded company, includingbenefits, stock compensation expense, legal, auditing and filing fees, additional insurance premiums, investor relations expenses and general compliance and consulting expenses.expenses We also expect our intellectual property related legal expenses, including those relateddue to preparing,the filing,completion prosecutingof andthe maintaining patent applications, to increase as our intellectual property portfolio expands.separation.

Non-cash interest expense was $22.5$20.9 million and $15.4$18.1 million during the three months ended SeptemberMarch 30,31, 20252026 and 2024,2025, respectively. The increase of $7.1$2.8 million in non-cash interest expense is primarily due to an increase in the GSK Jemperli Amendmentsales which increasedchanged the thresholdexpected amountstiming offor aggregate Jemperli royalties and milestonesSagard to be receivedpaid byper Sagard.the Jemperli Royalty Monetization Agreement.

Interest income was $2.9$2.7 million and $5.3$4.4 million during the three months ended SeptemberMarch 30,31, 20252026 and 2024,2025, respectively,respectively. whichThe decrease of $1.7 million in interest income was primarily related to our short-term and long-term investments. The decrease in interest income is primarily due to the decrease in investment balancesbalances, as well as the timing of sales, maturities and purchases of our investments.

Other Income (Expense), Income, Net

Other income (expense), income, net was $5.4 million of income and less than $0.1 million of expense and $1.9 million of income for the ninethree months ended SeptemberMarch 30,31, 20252026 and 2024,2025, respectively. The increasedecrease was primarily related to $5.4$1.9 million of other income recognized from existing drug supply transferred to Vanda in accordance with our Vanda License Agreement.

From our inception through SeptemberMarch 30,31, 2025,2026, we have received an aggregate of $1.3$1.4 billion to fund our operations, which included $740.2$766.4 million from the sale of equity securities, $335.0 million from the sale of future royalties, and $249.2$324.2 million from our collaboration agreements. As of SeptemberMarch 30,31, 2025,2026, and prior to the separation of First Tracks Biotherapeutics, we had $256.7$286.5 million in cash, cash equivalents and investments.

In addition to our existing cash, cash equivalents and investments, we are eligible to earn milestone and other contingent payments for the achievement of defined collaboration objectives and certain regulatory and sales-based events, and royalty payments under our collaboration agreements, including the GSK Agreement, the GSK Settlement Agreement, and the Vanda License Agreement. Our ability to earn these milestone and contingent payments and the timing of achieving these milestones is primarily dependent upon the outcome of our collaborators’ research and development and sales-based activities. Our rights to payments under our collaboration agreements are our only committed external source of funds.