Zasocitinib Demonstrates Efficacy in Moderate to Severe Psoriasis Treatment

A recent phase 2b trial of zasocitinib, a selective TYK2 inhibitor, demonstrated promising results in treating moderate to severe plaque psoriasis. Conducted across multiple centers in the U.S. and Canada, the study included 259 participants who received zasocitinib at varying doses (2, 5, 15, and 30 mg) or placebo over a 12-week period. The findings suggest that zasocitinib may offer effective skin clearance for patients with this challenging condition.

Dose-Dependent Efficacy Observed

At doses of 5 mg and above, zasocitinib achieved significant improvement in Psoriasis Area and Severity Index (PASI) scores, with up to 68% of patients reaching PASI 75 (75% improvement in severity). The highest dose (30 mg) resulted in complete skin clearance (PASI 100) for 33% of patients, with many showing improvement as early as four weeks into treatment. The efficacy was dose-dependent, with effects plateauing at 15 mg, indicating no substantial added benefit at higher doses for PASI 75.

Manageable Safety Profile

Safety data from the trial indicated that treatment-emergent adverse events (TEAEs) were more common in zasocitinib-treated patients (53-62%) compared to placebo (44%). Common TEAEs included acne, diarrhea, and COVID-19, with minimal discontinuations due to adverse events. Notably, no major cardiovascular or thromboembolic events were reported, a potential advantage compared to other treatment options affecting the JAK pathway.

Future Directions

With its rapid action, efficacy, and manageable safety profile, zasocitinib presents as a promising option for moderate to severe psoriasis. Two phase 3 trials of longer duration and larger patient populations are currently underway to further assess its potential for sustained symptom relief and broader applicability. If these trials confirm the phase 2b results, zasocitinib could expand the therapeutic options available to patients seeking effective, well-tolerated treatments for psoriasis.