Tirbanibulin Ointment 1% as a Novel Treatment for Actinic Keratosis: Phase 1 and 2 Results

Current field-directed treatments of actinic keratosis (AK), a pre-malignant condition, are often limited by severe local reactions and/or complex treatment. Tirbanibulin, a novel potent anti-proliferative synthetic agent that inhibits tubulin polymerization and Src kinase signalling, is being developed as a convenient, safe, and effective field treatment of actinic keratosis.

Steven Kempers MD, Janet DuBois MD, Seth Forman MD, Amy Poon BS MA, Eva Cutler BS BA, Hui Wang PhD, David Cutler MD FRCP(C), Jane Fang MD, Rudolf Kwan MBBS MRCP

Actinic keratosis (AK) is a pre-malignant condition, associated with prolonged ultraviolet damage predominantly on the face/scalp, trunk, and extremities. AK affects ~58 million individuals in the US, and typically occurs in males, fair-skinned individuals, and those of advancing age. As the progression of AK to invasive squamous cell carcinoma (iSCC) is unpredictable, the generally accepted approach is to treat all AK.

Current treatments are lesion- or field-directed therapies. Lesion-directed therapies are used when the lesion burden is low; but these modalities can cause scarring and long-term pigmentary changes. Field-directed therapies are used to treat multiple lesions, large areas, and subclinical lesions.

Commonly used topical treatments, while effective, frequently cause moderate-to-severe application-site reactions and deleterious effects on uninvolved skin, which are often considered unacceptable to patients. Moreover, many of these treatments have lengthy or cumbersome dosing regimens that may undermine treatment compliance and compromise efficacy.

Given the disadvantages of available topical therapies, there is a need to develop an agent that has low potential for severe local reactions, effective AK clearance, and convenient dosing.