Zasocitinib Demonstrates Efficacy and Safety in Phase 2b Psoriatic Arthritis Trial

Zasocitinib (TAK-279), an investigational oral tyrosine kinase 2 (TYK2) inhibitor, demonstrated improvements in joint and skin outcomes among adults with active psoriatic arthritis (PsA) in a randomized, phase 2b, placebo-controlled study.

In the 12-week trial, patients receiving zasocitinib 30 mg or 15 mg once daily achieved significantly higher American College of Rheumatology 20% (ACR20) response rates (54.2% and 53.3%, respectively) compared with placebo (29.2%; P = .002 for both doses). Numerically greater ACR50 and ACR70 responses were also observed at these doses, along with higher rates of Psoriasis Area and Severity Index 75% (PASI75) improvement and minimal disease activity.

Most adverse events were mild to moderate and occurred more frequently at higher doses. No new safety signals or dose-dependent laboratory abnormalities were identified over the 12-week treatment and 4-week follow-up period.

These findings indicate that zasocitinib may offer a promising oral therapeutic option for PsA, with efficacy across joint and skin domains. Larger and longer studies are ongoing to further confirm its safety and efficacy profile.