Acelyrin announces izokibep trial did not meet primary endpoint

Acelyrin (SLRN) announced that its Phase 2b/3 trial of izokibep in non-infectious, non-anterior uveitis did not meet the primary endpoint of a statistically significant improvement in time to treatment failure versus placebo as measured by treatment failure rates at 24 weeks. Based on these data, and previously announced guidance regarding other indications, Acelyrin will not make any additional internal investment in developing izokibep. Acelyrin will continue to focus on executing its late-stage development program for lonigutamab in thyroid eye disease. The Phase 2b/3 clinical trial evaluated izokibep versus placebo in non-infectious, non-anterior uveitis. Patients in the study were randomized 1:1 to receive weekly subcutaneous injections of izokibep 160 mg or placebo. The primary endpoint of the study was improvement in time to treatment failure versus placebo as measured by treatment failure rates at 24 weeks. Key secondary endpoints included measurement of the change in best corrected visual acuity, change in visual function as measured by the National Eye Institute’s Visual Function Questionnaire, percent change in central retinal thickness as measured by Spectral-Domain Optical Coherence Tomography and achievement of Quiescence. In the trial, the treatment failure rate at 24 weeks was 45% for izokibep and 50.7% for placebo. Statistical significance was not reached for any secondary endpoint and no clinical benefit was observed. Izokibep was well-tolerated in the trial, with a safety profile consistent with previous data and the IL-17A class. Acelyrin’s revised operating plan in connection with the announcement of the pipeline prioritization and corporate restructuring on August 13 included the funding of two Phase 3 trials and BLA-enabling activities for lonigutamab, selective pipeline expansion and the completion of the izokibep uveitis trial. Consistent with that plan, there will be no organizational or operational plan changes related to today’s announcement. The company continues to project that its existing cash resources will provide runway to mid-2027.