TYK2 Inhibitor Effective for Psoriasis in Phase 2 Study

TOPLINE:

Zasocitinib, a tyrosine kinase 2 (TYK2) inhibitor, at oral doses of ≥ 5 mg led to greater skin clearance than placebo over a period of 12 weeks, in a phase 2b study.

METHODOLOGY:

• Researchers performed a phase 2b, randomized, double-blind trial to assess the efficacy, safety, and tolerability of different doses of zasocitinib in adults with moderate to severe psoriasis (mean age, 47 years; 32% women) at 47 centers in the United States and eight centers in Canada. Most (83%) were White, 7% were Black, and 8% were Asian.
• A total of 287 patients were randomly assigned to receive one of the four oral doses of zasocitinib (2 mg, 5 mg, 15 mg, or 30 mg, once daily) or a matched placebo for 12 weeks, followed by a 4-week safety monitoring period.
• The primary outcome was the proportion of patients achieving a ≥ 75% improvement in the Psoriasis Area and Severity Index score (PASI 75) from baseline at week 12.

TAKEAWAY:

• At week 12, PASI 75 was achieved by 18%, 44%, 68%, and 67% of patients receiving zasocitinib at doses of 2 mg, 5 mg, 15 mg, and 30 mg, respectively, vs 6% of patients receiving placebo.
• PASI 90 was achieved in 8%, 21%, 45%, and 46% of patients receiving zasocitinib at 2 mg, 5 mg, 15 mg, and 30 mg, respectively, and in no patients in the placebo group.
• At week 12, 10%, 27%, 49%, and 52% of patients receiving zasocitinib at 2 mg, 5 mg, 15 mg, and 30 mg, respectively, had no or mild disease (a score of 0 or 1) according to the Physician Global Assessment tool vs 4% in the placebo group.
• Treatment-emergent adverse events occurred in 53%-62% of patients in the zasocitinib groups compared with 44% in the placebo group. The most common were COVID-19, acne/acneiform dermatitis, and diarrhea. There were no reports of major adverse cardiovascular events, thromboembolic events, or opportunistic infections.

IN PRACTICE:

“Zasocitinib, an advanced, potent, and highly selective oral TYK2 inhibitor bioengineered to optimize target coverage and functional selectivity, achieved biologic-level efficacy with complete skin clearance observed after only a 12-week treatment period in up to one third of patients, with a low incidence of known tolerability issues and absence of serious toxic effects that are characteristic of [Janus kinase] 1-3 inhibition,” the authors wrote.

SOURCE:

The study was led by April W. Armstrong, MD, MPH, University of California, Los Angeles, and was published online on August 21, 2024, in JAMA Dermatology.

LIMITATIONS:

The study was limited by a relatively small sample size and a short duration. In addition, the inclusion of predominantly White patients may limit the generalizability of findings to a diverse population.

DISCLOSURES:

The study was funded by Nimbus Discovery, which includes Nimbus Therapeutics and Nimbus Lakshmi. Dr. Armstrong’s disclosures included receiving grants and/or personal fees from various pharmaceutical companies, including Nimbus Therapeutics and Nimbus. Three authors were employees of and reported holding equity, stocks, or shares in Nimbus. Several authors had disclosures related to pharmaceutical companies, including Nimbus.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.