Safety and Tolerability of Tirbanibulin 1% Treatment of Actinic Keratosis on Face and Scalp in Routine Clinical Practice Across the U.S. (PROAK Study)

Abstract

Introduction: Actinic Keratosis (AK) has been shown to negatively affect emotional and social functioning and skin-related quality of life of patients [1]. The objective of this analysis was to evaluate safety and tolerability of tirbanibulin in AK treatment, among patients administered tirbanibulin in routine clinical practice across the U.S. Methods: A single-arm, multicenter, prospective cohort study (PROAK: NCT05260073) was conducted in adult patients with AKs on 25 cm2 on the face or scalp who were newly initiated with once-daily tirbanibulin 1% ointment treatment (5 consecutive days course) as part of usual care. Safety and tolerability endpoints were assessed at Week-8 and Week-24 and included adverse events (AEs), serious AEs (SAE), adverse drug reactions (ADRs), serious ADRs, local skin reactions (LSR), skin scarring and pigmentation (hypo/hyperpigmentation). Number of patients discontinuing treatment because of AEs, ADRs and for any other reasons were also reported. LSR (erythema, flaking/scaling, crusting, swelling, vesiculation/pustulation, and erosion/ulceration) were scored 0-3 (absent-severe) and summed to a composite score (0-18). Results: A total of 300 patients were included in the safety analysis population (males: 68%; mean age: 67 years; Fitzpatrick skin type II: 89%; AK on the face: 78%). A total of 98% of patients completed the 5-day treatment course. During the study, 5% of patients reported at least one AE, 4% of patients at least 1 SAE, and no patients reported serious ADR. Basal Cell Carcinoma was reported in 1% of patients and Squamous Cell Carcinoma in 2% of patients; all cases were considered not related to treatment.  No patients discontinued the study due to AEs or ADRs. At Week-8, the most reported LSR were erythema (48% mild-moderate, 5% severe) and flaking/scaling (50% mild-moderate, 3% severe). The rest of LSR were reported in 2-8% of patients (8% crusting, 5% swelling, 2% vesiculation/pustulation, and 2% erosion/ulceration) and all were mild-moderate in severity. Mean (min-max) LSR composite score was 0.94 (0-11). At Week-8, scarring or hypo/hyperpigmentation was observed in 1%, 5% and 3% of patients, respectively.   Conclusions: Once-daily tirbanibulin 1% ointment for 5 consecutive days showed a favorable safety and tolerability profile in the treatment of AK of the face or scalp. [1] Schlesinger T et al. Skin. 2023;7(3):771-787.