Material Event (Form 8-K)

On September 15, 2026, Coya Therapeutics, Inc. (the "Company") issued a press release announcing that the one hundredth (100^th) patient has been enrolled in the Company's ongoing Phase 2/3 ALSTARS Trial (NCT07161999) evaluating COYA 302, the Company's combination of proprietary low-dose IL-2 and CTLA-4 Ig, for the treatment of amyotrophic lateral sclerosis ("ALS"). Based on current enrollment trends, the Company anticipates completing full enrollment of 120 participants in sufficient time to permit reporting topline data in early Q2 of 2027.

The ALSTARS Trial is a Phase 2/3, randomized, multi-center, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of COYA 302 in patients with ALS. Approximately 120 subjects will be randomized 1:1:1 to receive one of two pre-specified dosing regimens of COYA 302 or placebo during a 24-week double-blind treatment phase. Patients who complete the 24-week placebo-controlled phase enter a 24-week blinded active-treatment extension phase; patients receiving COYA 302 continue their assigned regimen, while placebo patients are re-randomized to one of the two COYA 302 dosing regimens, providing up to 48 weeks of data on COYA 302. The primary endpoint is change in disease severity over time, measured by the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) total score from baseline to Week 24 compared with placebo. Study objectives include evaluation of efficacy, safety and tolerability, biological activity, and biomarker levels.