The biotechnology firm Evommune announced top-line results from a Phase 2b clinical trial of EVO756 for moderate-to-severe chronic spontaneous urticaria on Monday, revealing the study did not meet its primary efficacy endpoint. Consequently, the company will discontinue development for this indication and pivot its exploration towards atopic dermatitis and migraine prevention.

The randomized, double-blind, placebo-controlled Phase 2b study enrolled 160 patients with moderate-to-severe antihistamine-refractory CSU across the United States, Europe, Canada, and Japan. Participants were treated with one of three different doses of EVO756 or a placebo. Results indicated that at the 12-week mark, none of the dose groups demonstrated improvement superior to the placebo on the primary endpoint, which measured the mean change from baseline in the 7-day Urticaria Activity Score.

Evommune's Chief Medical Officer, Eugene Bauer, stated that although EVO756 previously yielded positive data in a Phase 2 study for chronic inducible urticaria and showed clear target engagement in Phase 1 trials, the lack of efficacy in this study does not support its continued development for CSU.

However, the study confirmed that EVO756 was safe and well-tolerated across all active dose groups, with no new safety signals identified. This finding provides support for its development in other indications. The company's CEO, Luis Peña, expressed continued belief that MRGPRX2 modulation represents a promising new therapeutic approach capable of reducing inflammation and providing rapid symptom relief.

Evommune will proceed with clinical studies of EVO756 for atopic dermatitis and migraine prevention. The company anticipates releasing top-line Phase 2b data for atopic dermatitis treatment in the third quarter of 2026 and has already initiated patient screening for its Phase 2b study in migraine prevention.

Following this announcement, Evommune's stock price plummeted by nearly 40% on Monday. Some analysts noted that the failure of the CSU study could further diminish investor confidence in the drug's potential for atopic dermatitis or other pruritus-related indications.