Annexon (ANNX) investor relations material

Company overview and late-stage programs

• Focuses on complement inhibition to address neuroinflammation in diseases of the brain, eye, and body, with two late-stage programs: one in Guillain-Barré syndrome (GBS) and one in geographic atrophy (GA).

• Achieved success in a large phase III GBS study, with regulatory filings in Europe and planned U.S. submission.

• GA program is the only one globally to show significant vision preservation and photoreceptor protection, with a large phase III readout expected in Q4.

Geographic atrophy (GA) program insights

• GA affects 8 million people worldwide; current approved drugs offer only symptomatic benefit, not vision preservation.

• Phase II ARCHER study showed statistically significant, dose-dependent vision preservation on all functional endpoints, including best-corrected visual acuity and low luminance visual acuity.

• Demonstrated a 73% reduction in risk of >15 letter loss at 12 months, a clinically meaningful outcome for patients.

• Mechanistically, C1q inhibition protects photoreceptors first, leading to downstream RPE preservation; effect on RPE lesion growth increased in the second six months of the study.

• Ellipsoid zone (EZ) is now the preferred structural endpoint, with the program showing 50-60% protection in the central fovea at one year, outperforming other therapies.

Phase III ARCHER II study design and execution

• 659 patients randomized 2:1 to monthly vonaprument or sham; primary endpoint is confirmed 15 letter loss at two consecutive visits, assessed at months 15 and 24.

• Patient cohorts and enrollment criteria closely matched to phase II, with exclusion of those with very poor vision to optimize event rates.

• Dropout rate is below 10% and compliance exceeds 90%, attributed to strong physician and patient belief in the therapy and its tolerability.

• Study is powered above 90% for both U.S. and European filings, with conservative assumptions for sham and treatment effects.

• Dual primary endpoints at months 15 and 24 leverage increased power from over-enrollment and retention, aiming for robust efficacy and commercial differentiation.