Acelyrin's Lead Drug Candidate Hits Primary Goal In Late-Stage Psoriatic Arthritis Study

Monday, Acelyrin Inc SLRN announced that its global Phase 2b/3 clinical trial of izokibep in psoriatic arthritis (PsA) met the primary endpoint of ACR50 at week 16 with high statistical significance. 

Results from the 160 mg weekly (QW) and every other week (Q2W) 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. 

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 < 3%. 

The company said that consistent high magnitude absolute responses were demonstrated in the Phase 2-comparable population, although enthesitis (pain and stiffness of joints) resolution overall was not statistically significant due to high placebo response. 

Izokibep achieved clinically meaningful resolution in patients with the highest burden of enthesitis (baseline LEI 3-6) relative to placebo, an effect not previously reported by other agents, the company added.

Concurrently, Acelyrin announced long-term data from a Phase 2b clinical trial of izokibep in hidradenitis suppurativa (HS), a chronic inflammatory condition that causes painful bumps under the skin.

The data demonstrated no evidence of increased safety liability with longer-term treatment, and increased duration of therapy was associated with further clinical improvements over time.

Patients who switched from placebo to izokibep at week 16 achieved a similar speed and magnitude of response as those who began treatment with izokibep at baseline for HiSCRs, draining tunnels, skin pain and Dermatology Life Quality Index (DLQI). 

High orders of HiSCR were achieved, with most patients achieving HiSCR75 and about a third achieving HiSCR100 by week 16 and through 32 weeks.

Topline data from an ongoing phase 3 trial in HS is expected by the end of 2024.

Price Action: SLRN shares are up 7.35% at $8.03 on the last check Monday.