Acelyrin says Phase 2b/3 trial of izokibep met primary endpoint

ACELYRIN announced its global Phase 2b/3 clinical trial of izokibep in psoriatic arthritis met the primary endpoint of ACR50 at week 16 with high statistical significance. Results from the 160 mg weekly and every other week arms showed improved magnitude of responses on higher hurdle endpoints such as ACR70, PASI100, and Minimal Disease Activity relative to the Phase 2 80 mg Q2W dose. This is notable given a higher baseline disease burden in the Phase 2b/3 trial population relative to the Phase 2 trial. Izokibep was well-tolerated with a favorable safety profile consistent with previous experience and the IL-17A class, without evidence of the safety liabilities observed with targeting IL-17A&F. The trial had a low study discontinuation rate of less than 3%. Mild-to-moderate injection site reactions were observed with discontinuations due to ISR less than 2%. There were two cases of mild candida – one in the placebo arm and one in the 160 mg QW arm – and no cases of suicidal ideation/behavior. Pre-specified analyses continue to support the potential for differentiation in enthesitis resolution. Consistent high magnitude absolute responses were demonstrated in the Phase 2-comparable population although enthesitis resolution overall was not statistically significant due to high placebo response. Izokibep achieved clinically meaningful resolution in patients with the highest burden of enthesitis relative to placebo an effect not previously reported by other agents. Additional information about these results can be found at ACELYRIN.com. Further data from this trial will be presented at future scientific meetings.