Zasocitinib shows promise as psoriasis treatment

In the treatment of psoriasis, selective inhibition of tyrosine kinase 2 (TYK2) with zasocitinib appears to have superior effects compared with placebo, with greater skin clearance observed over 12 weeks, according to data from a phase 2b study.

The analysis included 259 adults (mean age 47 years, 32 percent female) with a Psoriasis Area and Severity Index (PASI) score of at least 12, a Physician’s Global Assessment score of at least 3, and a body surface area covered by plaque psoriasis of at least 10 percent. These patients were randomly assigned to receive zasocitinib at 2, 5, 15, or 30 mg or placebo orally, once daily, for 12 weeks. All participants were followed-up for another 4 weeks after treatment.

The primary efficacy endpoint was the proportion of patients achieving at least a 75-percent improvement in PASI score (PASI 75) at week 12. Secondary efficacy endpoints included PASI 90 and 100 responses. Safety was also evaluated.

At week 12, more patients who received zasocitinib vs placebo achieved the primary endpoint of PASI 75. The corresponding proportions were 18 percent in the 2-mg dosing group, 44 percent in the 5-mg dosing group, 68 percent in the 15-mg dosing group, 67 percent in the 30-mg dosing group, and 6 percent in the placebo group.

Results for the PASI 90 response were consistent with those observed for the primary endpoint. Meanwhile, a clear dose-response effect was observed for the PASI 100 response, which was achieved by 33 percent of participants who received zasocitinib 30 mg.

Treatment-emergent adverse events occurred in between 53 percent and 62 percent of participants on zasocitinib and in 44 percent of those on placebo. Analysis of laboratory parameters showed no dose dependency and no clinically meaningful longitudinal differences.