Vonaprument

Tanruprubart MAA Filed with Potential to Be the First Targeted Fast-Acting Therapy for Guillain-Barré Syndrome (GBS); BLA Submission with U.S./European Data Planned in 2026 Vonaprument Pivotal Phase 3 Topline Data for Dry AMD with Geographic Atrophy (GA) on Track for Second Half of 2026 Evaluating Unprecedented Effect on Vision Protection Proof-of-Concept Data for ANX1502, the First Oral C1 Inhibitor for Autoimmune Disease, Expected in 2026 Strong Financial Position Funds Operations into Late 2027 Well Past Anticipated Key Milestones BRISBANE, Calif., Jan. 12, 2026 (GLOBE NEWSWIRE) -- Annexon, Inc. (Nasdaq: ANNX), a biopharmaceutical company advancing the next generation platform of targeted immunotherapies aimed at neuroinflammatory diseases that impact nearly 10 million people worldwide, today highlighted its 2026 strategic priorities and key milestones for its lead programs. “2026 is a pivotal year for Annexon as we progress toward our first potential approval in GBS and pivotal Phase 3 data in GA,” said Douglas Love, president and chief executive officer of Annexon. “Building on more than a decade of expertise stopping acute and chronic neuroinflammation at its source, our two registrational programs have both demonstrated meaningful patient benefit in well-controlled trials by significantly protecting function in devastating diseases. As a result, vonaprument and tanruprubart both have the potential to reset the standard of care in their respective diseases and help millions of patients live their best lives.” Mr. Love continued, “With tanruprubart’s Marketing Authorization Application (MAA) filed in Europe and the U.S./European FORWARD trial underway to support a planned U.S. BLA submission in 2026, we are increasingly focused on our vonaprument GA program and its upcoming pivotal data later this year. The strong biologic rationale and unprecedented effect on vision protection demonstrated in the Phase 2 trial provide confidence in the potential of vonaprument to replicate the findings and thereby preserve vision for the eight million people worldwide living with GA. With seasoned leadership and a strong financial position, we are energized by the year ahead and the potential to deliver significant value for patients and stakeholders.” 2026 Strategic Priorities and Key Milestones Vonaprument– Potential to be the first targeted vision-preserving therapy for GA Ongoing Phase 3 ARCHER II trial is a global, pivotal, sham-controlled, double-masked trial. The primary endpoint is the proportion of patients who experience a best corrected visual acuity (BCVA) 15-letter loss confirmed at two consecutive visits, measured at month 15. Enrollment of 659 patients completed ahead of schedule and exceeded target patient numbers. Patient selection profile similar to the Phase 2 trial, with enrichment strategies designed to include patients at higher risk for vision loss. Global registration path established with U.S. and European regulators for ARCHER II, supporting the potential of vonaprument to be the first treatment approved for protection of vision in patients who have dry AMD with GA. Consistent with its neuroprotective mechanism, vonaprument provided significant protection of photoreceptors within the center of the retina necessary for visual acuity and significantly protected vision on multiple clinical measures. Annexon plans to host a GA Investor Day in March 2026 featuring management, key opinion leaders and retina experts to provide deeper insight on the vonaprument program and its potential impact in the GA landscape. Next Milestone: Topline Phase 3 ARCHER II trial data expected in second half of 2026. Tanruprubart – Potential to be the first targeted fast-acting therapy for GBS MAA filed with European Medicines Agency with comprehensive data package demonstrating rapid impact on markers of neuroinflammation and disease activity, and patients recovering faster and more completely on both disability and functional outcome measures in placebo-controlled studies. Also submitted data showing improved outcomes versus standard of care intravenous immunoglobulin (IVIg) or plasma exchange (PE) in a Real-World Evidence study. Ongoing open-label FORWARD study in the U.S. and Europe, designed to support a broad label across pediatric and adult patients and further expand the use of tanruprubart across geographies. Next Milestone: BLA submission with U.S./European data from FORWARD trial planned in 2026. ANX1502 for Autoimmune Conditions – First-in-kind oral small molecule with convenient and flexible dosing Evaluation of pharmacokinetics (PK) and pharmacodynamics (PD) in relation to food intake, and reduction in complement activity (as a measure of target engagement), and bilirubin (as a measure of hemolysis) is ongoing in proof-of-concept (POC) trial in patients with cold agglutinin disease (CAD). Objective measurements of clinical activity in CAD patients are anticipated to be translatable across a host of neuromuscular autoimmune diseases. Next Milestone: Update on POC trial in CAD anticipated in 2026. About Annexon Annexon Biosciences (Nasdaq: ANNX) is advancing the next generation platform of targeted immunotherapies for nearly 10 million people worldwide living with serious neuroinflammatory diseases. Our founding scientific approach focuses on C1q, the initiating molecule of a potent inflammatory pathway that when misdirected can lead to tissue damage and loss of function in a host of diseases. Our targeted therapies are designed to stop classical complement-driven neuroinflammation at its source to provide meaningful functional benefit and alter the course of disease. Annexon’s mission is to deliver game-changing therapies to patients so that they can live their best lives. To learn more visit annexonbio.com. Forward Looking Statements This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In some cases, you can identify forward-looking statements by terminology such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “design,” “due,” “estimate,” “expect,” “goal,” “intend,” “may,” “objective,” “plan,” “positioned,” “potential,” “predict,” “seek,” “should,” “target,” “will,” “would” and other similar expressions that are predictions of or indicate future events and future trends, or the negative of these terms or other comparable terminology. All statements other than statements of historical facts contained in this press release are forward-looking statements. These forward-looking statements include, but are not limited to the potential therapeutic benefit of tanruprubart, if approved, compared to existing therapies; anticipated timing and results of regulatory interactions related to tanruprubart, including the timing of the company’s planned BLA submission to the U.S. Food and Drug Administration (FDA); the design, objectives and timing of the open-label tanruprubart FORWARD study; the company’s ability to achieve regulatory approval for tanruprubart; the potential therapeutic benefit of vonaprument; timing of and results from the Phase 3 ARCHER II trial; vonaprument’s distinct potential neuroprotective mechanism of action and potential to provide protection from vision loss; the potential for vonaprument to be the first drug approved for dry AMD with GA; the potential for vonaprument and tanruprubart to reset the standard of care; timing of proof-of-concept trial for ANX1502 in CAD and the company’s ability to provide an update upon completion of its POC trial in 2026; the company’s ability to commercialize its product candidates, if approved; the potential for the company to deliver significant value for patients and its stakeholders; and continuing advancement of the company’s portfolio. Forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including, but not limited to, risks and uncertainties related to: the company’s history of net operating losses; the company’s ability to obtain necessary capital to fund its clinical programs; the potential for delays in the company’s clinical trials; the potential for the company’s product candidates to not receive regulatory approval, including if the FDA and comparable foreign regulatory authorities determine that the company’s submission package is not sufficient or require the company to provide additional data in patients that are not feasible to obtain; the early stages of clinical development of the company’s product candidates; the effects of public health crises on the company’s clinical programs and business operations; the company’s ability to obtain regulatory approval of and successfully commercialize its product candidates; any undesirable side effects or other properties of the company’s product candidates; the company’s reliance on third-party suppliers and manufacturers; the outcomes of any future collaboration agreements; and the company’s ability to adequately maintain intellectual property rights for its product candidates. These and other risks are described in greater detail under the section titled “Risk Factors” contained in the company’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q and the company’s other filings with the Securities and Exchange Commission. Any forward-looking statements that the company makes in this press release are made pursuant to the Private Securities Litigation Reform Act of 1995, as amended, and speak only as of the date of this press release. Except as required by law, the company undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise. Investor Contact: Joyce Allaire LifeSci Advisors jallaire@lifesciadvisors.com Media Contact: Beth Keshishian 917-912-7195 beth@bethkeshishian.com

Late-Stage Neuroinflammation Platform Advancing Global Registrational Programs in Guillain-Barré Syndrome (GBS) and Geographic Atrophy (GA) Current Tanruprubart GBS Dossier On Track for MAA Filing in January 2026; Potential to Be the First Approved Targeted and Fast-Acting Therapy for the Treatment of GBS; Continued FDA Discussions Regarding Generalizability Package in Support of BLA Filing Topline ARCHER II Pivotal Data for Vonaprument in Dry AMD with GA on Track for Second Half of 2026; Potential to Be the First Approved Vision Sparing Therapy for the Treatment of Eight Million GA Patients Worldwide ANX1502 Cold Agglutinin Disease (CAD) Proof of Concept Study Ongoing with Expected 2026 Completion; Potential to Be the Only Oral C1s Inhibitor for the Treatment of Multiple Neuroinflammatory Autoimmune Diseases Strong Financial Position and Execution Extends Operations into 2027, Through Several Important Milestones, Including Tanruprubart Global GBS Filings, Vonaprument Topline GA Phase 3 Data, and ANX1502 Autoimmune Proof of Concept Data BRISBANE, Calif., Nov. 10, 2025 (GLOBE NEWSWIRE) -- Annexon, Inc. (Nasdaq: ANNX), a biopharmaceutical company advancing a late-stage clinical platform targeting neuroinflammation across life-changing complement-mediated neuroinflammatory diseases of the body, brain, and eye, today highlighted portfolio progress, announced key anticipated milestones and reported third quarter 2025 financial results. “We’re pleased with the focused execution of our business strategy across our late-stage neuroinflammation platform, and the strong momentum we’ve built over 2025 heading into a meaningful 2026. Our next-generation complement inhibitor candidates continue to demonstrate the power of stopping neuroinflammation at its source, enabling multiple programs advancing toward key near-term milestones,” said Douglas Love, president and chief executive officer of Annexon. “Our registrational Guillain-Barré Syndrome program is on track for EU Marketing Authorisation Application (MAA) submission in January 2026, positioning it to become the first targeted therapy for GBS, a disease that annually affects 150,000 people worldwide. Dialogue with the FDA is also ongoing regarding the generalizability package supporting the U.S. Biologics License Application (BLA) submission. Furthermore, our registrational Phase 3 trial for vonaprument in GA is on track to deliver topline data in the second half of 2026. The study is designed to confirm the significant vision preservation observed in our Phase 2 trial and benefit the eight million people affected by GA worldwide.” Mr. Love continued, “Finally, we are building on the early learnings from our ANX1502 program, the first and only clinical stage oral inhibitor of C1s. We’ve observed targeted drug levels in fasted CAD patients, and we continue to dose to deepen our understanding of ANX1502’s profile, anticipating study completion in 2026. With a prioritized capital plan, our runway is extended into 2027 through each of the above anticipated milestones. Overall, Annexon is uniquely positioned to drive near-term value while pursuing additional opportunities to achieve our mission of helping millions of patients suffering from devastating neuroinflammatory diseases.” Recent Corporate and Clinical Program Updates Tanruprubart (ANX005) in GBS: Targeted neuroinflammatory inhibitor of C1q and the classical pathway delivered in a single infusion to rapidly halt aggressive neuroinflammation and damage in GBS, an acute, rare, neuromuscular emergency that affects ~150,000 people worldwide each year. There are no FDA-approved therapies for GBS and limited evidence of effectiveness from the current standards of care (SOC) therapy used in GBS. Productive regulatory interactions with European Rapporteurs and Pediatric Committee of the European Medicines Agency reaffirm the current tanruprubart GBS data package is on track for MAA filing in January 2026. Collaborative discussions with the FDA on the generalizability package to support the BLA submission are ongoing. Large biomarker dataset from the Phase 3 trial reinforces that, distinct from current standard of care therapies, tanruprubart has a rapid impact on the acute inflammatory process across all GBS subtypes, supporting the consistency of its rapid benefit on function and disability across geographies. U.S. and European FORWARD open-label study designed to broaden Western experience with tanruprubart, including in pediatric patients, is ongoing with initial pharmacokinetic (PK), pharmacodynamic (PD), biomarker and functional data anticipated in 2026. Continued ongoing discussions with pharmaceutical companies on collaboration opportunities to commercialize tanruprubart for GBS in various geographies. Next Milestones: Tanruprubart MAA submission expected in January 2026. Update on FDA BLA submission upon further regulatory dialogue. Initial FORWARD data anticipated in 2026. Vonaprument (ANX007) in Dry AMD Patients with GA: Neuroprotective inhibitor of C1q and the classical complement cascade delivered intravitreally for dry AMD with GA, a leading cause of blindness affecting more than eight million people worldwide. There are no approved therapies for GA targeting the preservation of vision. Registrational Phase 3 ARCHER II trial, a global, sham-controlled, double-masked trial, completed enrollment early in July 2025 while also exceeding enrollment targets for a total of 659 GA patients. ARCHER II is the first study to evaluate a therapy for dry AMD with GA targeting visual function as the primary endpoint measured by the gold-standard best corrected visual acuity 15-letter loss (BCVA ≥15LL). Vonaprument selected by European Medicines Agency (EMA) for the exclusive Product Development Coordinator (PDC) pilot launched in July 2025 to assist Priority Medicine (PRIME) designation holders in navigating regulatory interactions, including expedited scientific advice, MAA submission readiness activities, and ad-hoc queries throughout the development program. Recent positive engagements with FDA and EMA support the established vonaprument ARCHER II global regulatory approval path for protection of vision in patients with GA. Further analyses of the Phase 2 ARCHER trial reinforce that structural protection of photoreceptors within the center of the retina is critical to visual acuity, consistent with neuroprotective mechanism of vonaprument. In the Phase 2 trial, vonaprument treatment showed 73% reduction in risk of vision loss measured by the gold-standard BCVA ≥15-letter loss endpoint, protection of photoreceptors with greatest impact near the center of the retina, and trends towards greater RPE protection over time and also near the center of the retina. Next Milestone: Topline Phase 3 ARCHER II trial data expected in second half of 2026. ANX1502 for Autoimmune Conditions: First-in-kind oral C1s inhibitor, has the potential to offer disruptive advantages of clinically validated upstream classical complement inhibition with the convenience and flexibility of oral administration. Currently evaluating an enteric-coated tablet formulation of ANX1502 in an open-label, single arm, POC study in patients with CAD. Drug levels at and exceeding pre-defined target in fasted CAD patients observed in the POC trial, and dosing is ongoing to further enhance the understanding of ANX1502’s PK/PD profile, including effect on complement and clinical markers of hemolysis. POC study completion anticipated in 2026. Next Milestone: ANX1502 program update upon CAD study completion in 2026. Third Quarter 2025 Financial Results Cash and operating runway: Cash and cash equivalents and short-term investments were $188.7 million as of September 30, 2025. Based on focused investments in its lead late-stage programs, Annexon has extended its runway and expects to fund operations and anticipated milestones into late first quarter 2027. Research and development (R&D) expenses: R&D expenses were $49.7 million for the quarter ended September 30, 2025, compared to $30.1 million for the quarter ended September 30, 2024. The increased R&D expenses are primarily associated with the advancement of the Phase 3 ARCHER II trial of vonaprument in GA and investments toward completion of tanruprubart global filings for GBS. General and administrative (G&A) expenses: G&A expenses were $7.3 million for the quarter ended September 30, 2025, compared to $9.3 million for the quarter ended September 30, 2024. The decline in G&A expenses reflects ongoing corporate efficiencies and disciplined prioritization of resources. Net loss: Net loss was $54.9 million or $0.37 per share for the quarter ended September 30, 2025, compared to $34.8 million or $0.25 per share for the quarter ended September 30, 2024. About Annexon Annexon Biosciences (Nasdaq: ANNX) is developing the next generation of complement inhibitors to stop neuroinflammation as first-in-kind treatments for millions of people living with serious neuroinflammatory diseases of the body, brain and eye. Our novel scientific approach focuses on C1q, the initiating molecule of classical complement’s potent inflammatory pathway that when misdirected can lead to tissue damage and loss in a host of diseases. By targeting C1q, our immunotherapies are designed to stop this neuroinflammatory cascade before it starts. Our pipeline spans three diverse therapeutic areas – autoimmunity, neurodegeneration and ophthalmology – and includes targeted investigational drug candidates designed to address the unmet needs of nearly 10 million people worldwide. Annexon’s mission is to deliver game-changing therapies to patients so that they can live their best lives. To learn more visit annexonbio.com. Forward Looking Statements This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. In some cases, you can identify forward-looking statements by terminology such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “could,” “design,” “due,” “estimate,” “expect,” “goal,” “intend,” “may,” “objective,” “plan,” “positioned,” “potential,” “predict,” “seek,” “should,” “target,” “will,” “would” and other similar expressions that are predictions of or indicate future events and future trends, or the negative of these terms or other comparable terminology. All statements other than statements of historical facts contained in this press release are forward-looking statements. These forward-looking statements include, but are not limited to, statements about: the potential therapeutic benefit of ANX005, if approved, compared to existing therapies; anticipated timing and results of regulatory interactions related to ANX005; the design, objectives and timing of the open-label tanruprubart FORWARD study; the company’s ability to gain clarity from the FDA on the generalizability package to support a BLA submission; the company’s ability to make an MAA submission for European registration in January 2026 and to achieve regulatory approval for ANX005; the potential therapeutic benefit of ANX007; timing of and results from the Phase 3 ARCHER II trial; ANX007’s distinct potential neuroprotective mechanism of action and potential to provide protection from vision loss; the potential for ANX007 to be the first drug approved in Europe and the U.S. for dry AMD with GA; timing of proof-of-concept trial for ANX1502 in cold agglutinin disease and the company’s ability to provide an update upon study completion in 2026; the potential for ANX1502 to disrupt the current treatment antibody-mediated autoimmune diseases; the company’s ability to commercialize its product candidates, if approved; continued development of ANX007 and ANX1502; anticipated cash runway into late first quarter 2027; the potential benefits from treatment with anti-C1q therapy; and continuing advancement of the company’s portfolio. Forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including, but not limited to, risks and uncertainties related to: the final results from the Phase 3 ARCHER II trial; the company’s history of net operating losses; the company’s ability to obtain necessary capital to fund its clinical programs; the potential for delays in the company’s clinical trials, including if the FDA and comparable foreign regulatory authorities do not accept data from clinical trials for product candidates outside the United States; the early stages of clinical development of the company’s product candidates; the effects of public health crises on the company’s clinical programs and business operations; the company’s ability to obtain regulatory approval of and successfully commercialize its product candidates; any undesirable side effects or other properties of the company’s product candidates; the company’s reliance on third-party suppliers and manufacturers; the outcomes of any future collaboration agreements; and the company’s ability to adequately maintain intellectual property rights for its product candidates. These and other risks are described in greater detail under the section titled “Risk Factors” contained in the company’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q and the company’s other filings with the SEC. Any forward-looking statements that the company makes in this press release are made pursuant to the Private Securities Litigation Reform Act of 1995, as amended, and speak only as of the date of this press release. Except as required by law, the company undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise. Investor Contact: Joyce Allaire LifeSci Advisors jallaire@lifesciadvisors.com Media Contact: Beth Keshishian 917-912-7195 beth@bethkeshishian.com