TYK2 Inhibitor ICP-332 Demonstrates Efficacy, Safety in AD

KEY TAKEAWAYS

• Oral ICP-332 improved EASI scores over 4 weeks in moderate to severe AD, new research suggests.

• The reported safety profile was acceptable, with most adverse events mild to moderate in severity.

• Both 80 mg and 120 mg doses achieved EASI-75 response in 64% of patients.

A novel oral TYK2 inhibitor, ICP-332, demonstrated favorable safety and promising efficacy in a recent phase 2 randomized clinical trial for moderate to severe atopic dermatitis (AD).

Researchers for the double-blind, placebo-controlled study enrolled 75 adults from 19 Chinese centers looking at once-daily ICP-332 at 80 mg or 120 mg vs placebo over a 4-week period. The primary endpoint was safety. Mild to moderate treatment-emergent adverse events (TEAEs) occurred in 68% of placebo recipients vs 76% receiving 80 mg ICP-332 and 75% receiving 120 mg) according to the data. The most frequent AE was decreased blood fibrinogen, reported in 44% of the 80 mg group and 21% of the 120 mg group (vs 4% placebo).

Disease severity improved by week 4, with mean EASI reductions of −78.2% in the 80 mg group and −72.5% in the 120 mg group vs. −16.7% for placebo. Both doses outperformed placebo, with between-group differences of −61.6% (P < 0.001) and −55.8% (P < 0.001), respectively. Sixty-four percent of patients in both ICP-332 arms achieved EASI-75 (vs 8% placebo; difference, 56%; P < 0.001). Investigator-assessed clear or almost clear skin (IGA 0/1 with ≥2-point improvement) was reported in 36% of the 80 mg group and outperformed placebo (P = 0.005).

“In this phase 2 randomized clinical trial, ICP-332 demonstrated a favorable safety profile and encouraging efficacy, supporting further development for AD,” the authors wrote.

Source: Xu J, et al. JAMA Dermatology. 2026. doi:10.1001/jamadermatol.2025.5295