Bimiralisib Potential in Actinic Keratosis Demonstrated in Phase 2 Interim Data

New data presented at the 2025 American Academy of Dermatology (AAD) Annual Meeting demonstrate the potential of bimiralisib in management of actinic keratosis.

An interim analysis of a phase 2 trial of the selective pan-PI3K/mTOR inhibitor from Torqur AG, interim results presented at AAD 2025 indicate 60% of patients using of bimiralisib topical gel 2% achieved associated with complete or partial clearance of their lesions at their follow-up visit, with this number reaching 70% in the 4-week treatment group.

“Most instances of cutaneous squamous cell carcinomas begin as actinic keratosis. With more than 58 million Americans living with these lesions, new targeted, non-invasive treatments for early-stage growths could help to alleviate the burden of this disease for thousands of patients,” said David Fisher, chair of the Dermatology Department at Massachusetts General Hospital and Harvard Medical School.

A multicenter, randomized, open-label, parallel-group study conducted at a pair of centers in Switzerland, the trial was designed to randomize patients in a 1:1 ratio to receive topical bimiralisib gel treatment for 2 weeks or 4 weeks. For inclusion in the trial, patients needed to be of at least 50 years of age, have a clinical diagnosis of stable, clinically typical actinic keratosis, and have at least 3 actinic keratosis lesions contained within contiguous treatment regions of face and/or scalp and/or back of hands.1,2,3

As part of their participation in the trial, participants needed to agree not to use any product on the treatment area during the entire course of study except for Investigator-approved cleanser, sunscreen, wash, and non-medicated makeup. Additionally, female participants who had a menstrual cycle within 2 years prior to screening were required to have a negative serum pregnancy test at screening and a negative urine pregnancy test on their first treatment day.3

The trial’s primary outcome of interest is change from baseline in actinic keratosis lesions as measured by achieving an Investigator Global Assessment (IGA) score of 0 or 1 at day 43 or day 57, depending on treatment arm. Secondary efficacy outcomes of interest included the proportion of participants with partial or complete clearance of actinic keratosis lesions at the end of treatment visit.3

Data presented at AAD demonstrated 60% of patients who completed the initial treatment and follow-up visit achieved either complete or partial clearance of their lesions. Further analysis suggested complete or partial clearance of lesions was achieved by 70% in the 4-week treatment group and 50% in the 2-week treatment group. Safety analysis indicated the topical gel was well tolerated, with treatment-related adverse events primarily being mild (Grade 1) and resolving quickly after treatment completion.1,2

“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 principal investigator Alexander Navarini, MD, PhD, chairman of the Department of Dermatology and Allergy at the University Hospital Basel in Switzerland.2 “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 from the trial comes less than a year after Torqur AG announced dosing of the first patient within the trial. According to a release from Torqur AG, full results from the phase 2 trial are expected in June 2025.2

“These interim results mark a significant step forward in our commitment to bringing innovative therapeutic options to patients with actinic keratosis”, added Vladimir Cmiljanovic, CEO at Torqur AG.2 “We are highly encouraged by the positive trends observed and remain focused on advancing the study toward the next phase of development.”

Reference:

1. Steybe T, Lindemann H, Osterwalder B, et al. A randomized phase 2 proof-of-concept study to evaluate the efficacy and safety of topical bimiralisib application in patients suffering from actinic keratosis on the face and/or scalp and/or back of hands over a 2 and 4-week treatment period. Presented at the 2025 American Academy of Dermatology (ADA) Annual Meeting. Orlando, FL. March 07-11, 2025.

2. Torqur AG. Torqur AG Presents interim phase 2 clinical trial results at American Academy of Dermatology. Torqur. March 7, 2025. Accessed March 7, 2025. https://torqur.com/news/torqur-ag-presents-interim-phase-2-clinical-trial-results-at-american-academy-of-dermatology-2025.

3. Clinicaltrials.gov. Study on the Safety and Efficacy of Bimiralisib Gel in Participants Suffering From Actinic Keratosis. Clinicaltrials.gov. May 16, 2024. Accessed March 7, 2025. https://www.clinicaltrials.gov/study/NCT06319794.