Study: 60% Lesion Clearance in Actinic Keratosis Patients Using Topical Bimiralisib Gel

Newly presented interim results from a phase 2 clinical trial evaluating bimiralisib topical gel (2%) saw more than half of patients with actinic keratosis achieving complete or partial lesion clearance.

Bimiralisib, a pan-PI3K/mTOR inhibitor, targets the overactive PI3K pathway implicated in actinic keratosis, a common precancerous condition affecting 58 million Americans annually, according to a release from the manufacturer (Torqur). Researchers emphasize the importance of targeted, non-invasive therapies in reducing the risk of progression to cutaneous squamous cell carcinoma.

The study enrolled 35 patients with actinic keratosis from two dermatology centers in Switzerland. Patients were divided into two treatment arms: a two-week regimen (Arm A = 18 patients) and a four-week regimen (Arm B = 17 patients). The primary endpoint was lesion clearance; treatment safety was a secondary endpoint.

The results showed higher efficacy in the four-week group, (70% of participants showed significant lesion clearance vs. to 50% in the two-week group. Mild and transient adverse events were reported, and the treatment was well-tolerated by the patient population. 

“The interim results from this Phase 2 trial are highly encouraging, showing strong potential for bimiralisib topical gel (2%) as an effective and well-tolerated treatment for Actinic keratosis,” said Prof. Dr. Alexander Navarini, lead principal investigator and Chairman of the Department of Dermatology and Allergy at the University Hospital Basel in Switzerland, in a news release. “These encouraging interim findings further validate the need for effective, targeted therapies addressing the PI3K pathway in actinic keratosis. We look forward to building on this momentum and further assessing bimiralisib’s clinical potential as the study progresses.”

The interim data were presented at the 2025 AAD Annual Meeting in Orlando. Full study results are slated for release in June 2025, with further analysis expected.