Torqur AG Reports Promising Phase 2 Results for Bimiralisib Gel in Actinic Keratosis

Actinic keratoses affecting the face | Image Credit: © DermNet

Torqur AG shared promising interim results from its ongoing phase 2 clinical trial investigating bimiralisib gel 2% for the treatment of actinic keratosis (AK).¹ These findings were presented at the American Academy of Dermatology (AAD) Annual Meeting in Orlando, Florida, from March 7–11, 2025.

Recent studies have identified the phosphoinositide 3-kinase (PI3K)/mechanistic target of rapamycin (mTOR) pathway as a significant contributor to the development of AK. Overactivation of this pathway leads to uncontrolled cell proliferation and survival, highlighting it as a potential target for therapeutic intervention.²

Bimiralisib is a selective pan-PI3K/mTOR inhibitor formulated as a topical gel. Its design allows for localized inhibition of the PI3K/mTOR pathway, aiming to reduce AK lesion proliferation while minimizing systemic adverse effects.

Study Design and Methods

The ongoing phase 2 trial (NCT06319794) is a multi-center, randomized, open-label study evaluating the efficacy and safety of bimiralisib gel in patients with AK on the face, scalp, or back of hands.³ Participants are assigned to 1 of 2 treatment arms:

• Arm A: Topical application of bimiralisib gel once daily for 2 weeks.
• Arm B: Topical application of bimiralisib gel once daily for 4 weeks.

The study includes a screening period (up to 30 days), a treatment phase (2 or 4 weeks), and a follow-up period (4 weeks). The primary endpoint is the proportion of participants achieving an Investigator Global Assessment score of 0 or 1, indicating complete or near-complete clearance of AK lesions.

Interim Efficacy Results

As of the interim analysis, 60% of patients who completed the initial treatment and follow-up visit exhibited either complete or partial clearance of their lesions. Specifically:

• Arm A (2-week treatment): 50% of participants showed significant improvement.
• Arm B (4-week treatment): 70% of participants demonstrated significant improvement.

These findings suggest a potential dose-response relationship, with extended treatment duration correlating with enhanced efficacy.

Safety and Tolerability

Bimiralisib gel was well-tolerated across both treatment arms. Treatment-related adverse events were primarily mild (Grade 1) and resolved promptly after treatment completion. No serious adverse events were reported, indicating a favorable safety profile for the topical application of bimiralisib.

Expert Insights

David Fisher, MD, PhD, chair of the Dermatology Department at Massachusetts General Hospital and Harvard Medical School, emphasized the clinical significance of these findings.

"Most instances of cutaneous squamous cell carcinomas begin as actinic keratosis," Fisher said in a news release.¹ "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."

Lead principal investigator Dr Alexander Navarini, chairman of the Department of Dermatology and Allergy at the University Hospital Basel, added,¹ "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. 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."

Conclusion and Future Directions

The interim findings from this phase 2 trial highlight the potential of bimiralisib gel as a targeted, non-invasive treatment for AK. Full study results are anticipated in June 2025, which will provide more comprehensive data to inform subsequent clinical development phases.

References

1. Torqur AG presents interim phase 2 clinical trial results at American Academy of Dermatology. News release. Torqur AG. 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
2. Booty MG, Komalo B, Hosny A, et al. Oral mTOR inhibition limits and reduces actinic keratosis and cutaneous squamous cell carcinoma in a UVB-induced mouse model. bioRxiv. 2022.11.03.513568; https://doi.org/10.1101/2022.11.03.513568
3. Study on the safety and efficacy of bimiralisib gel in participants suffering from actinic keratosis. Identifier NCT06319794. Updated May 16, 2024. Accessed March 7, 2025. https://clinicaltrials.gov/study/NCT06319794?term=NCT06319794&rank=1