Tirbanibulin is a novel, first-in-class microtubule inhibitor which acts by direct binding to tubulin, thereby inducing cell cycle arrest and apoptotic death of proliferating cells with associated disruption of Src tyrosine kinase signalling.
Klisyri should be applied thinly to the affected field on the face or scalp (maximum treatment area, 25cm2) once daily. Unlike other topical treatments for actinic keratosis marketed in the UK, which require application for between three weeks and 12 weeks, Klisyri application should be continued for a single treatment cycle of five days.
The therapeutic effect of Klisyri should be assessed approximately eight weeks after start of treatment. If complete clearance of the treated area has not been achieved by this time treatment should be re-evaluated and management reconsidered.
Efficacy and safety of tirbanibulin were assessed in two pivotal phase III studies involving patients with four to eight clinically typical, visible, discrete, non-hyperkeratotic, non-hypertrophic, actinic keratosis lesions within a contiguous 25cm2 treatment field on the face or scalp who were randomised to receive treatment with tirbanibulin (n=353) or vehicle (n=349) for five consecutive days.
Pooled data from the two studies showed significantly higher rates of complete and partial clearance of actinic keratosis lesions at day 57 in the tirbanibulin group compared with the vehicle group (49% vs 9% and 72% vs 18%, respectively [p<0.0001]). Efficacy was lower in scalp lesions than in facial lesions but was still significant.
The most commonly reported adverse effects of tirbanibulin were local skin reactions of mild to moderate severity, including erythema, exfoliation, crusting, swelling, ulceration, pustulation, pruritus and pain. Overall, these reactions peaked eight days after start of treatment, typically resolving within two to three weeks after completion of therapy.