Tyrosine Kinase 2 Inhibition With Zasocitinib (TAK-279) in Psoriasis

JAMA Dermatology
Open Access

Clinical Summary

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What was studied

A phase 2b, randomized, double-blind, placebo-controlled trial across 55 North American sites tested oral zasocitinib 2, 5, 15, or 30 mg once daily vs placebo for 12 weeks in adults 18-70 with moderate to severe plaque psoriasis (PASI ≥12, PGA ≥3, BSA ≥10%; n=259 treated), followed by 4 weeks of follow-up. The primary endpoint was PASI 75 at week 12.

Key findings

At week 12, PASI 75 was achieved by 18%, 44%, 68%, and 67% with zasocitinib 2, 5, 15, and 30 mg vs 6% with placebo; PASI 100 occurred in 33% (17/52) at 30 mg. Treatment-emergent adverse events occurred in 53%–62% with zasocitinib vs 44% with placebo, with no dose dependency and no clinically meaningful lab changes reported.

Study limitations

Short treatment (12 weeks) with only 4-week follow-up limits assessment of durability and safety. Placebo-only comparator and a modest treated sample size (n=259) restrict comparative effectiveness and generalizability.

Clinical implications

Zasocitinib ≥5 mg daily improved skin clearance vs placebo over 12 weeks in moderate to severe plaque psoriasis, with similar short-term safety and no lab signal. Findings are phase 2b and exploratory; clinical use awaits longer-term and head-to-head phase 3 data.