Anatomic site–specific treatment response with 40% hydrogen peroxide (W/W) topical formulation for raised seborrheic keratoses: Pooled analysis of data from two phase 3 studies

Objective: Seborrheic keratoses (SKs) may present in any non-glabrous skin, but data are limited on the response to treatment as based on the SK location. We aimed to understand the relationship between SK location and clearance with up to 2 treatments of 40% (w/w) hydrogen peroxide topical solution (HP40). Methods: We conducted a sub-analysis of data pooled from two randomized, double-blind, vehicle (VEH)-controlled clinical trials, including 937 patients, each with 4 target SKs (N=3,748 SKs), with at least 1 on the face and 1 on the trunk or extremities. Treatment response was defined as 0 or 1 on a 4-point Physician’s Lesion Assessment (PLA) scale (0=clear; 1=near-clear) after up to 2 applications, 3 weeks apart, and was assessed by SK location (face, trunk, and extremity). Local skin reactions were stratified by anatomic location and categorized based on immediate and delayed post-treatment reactions. Sensitivity analysis was conducted using the mean-per-patient (MPP) percent of SKs that are clear or near-clear at day 106. Results: Treatment response was greater with HP40 versus VEH regardless of anatomic location of the SK. Clear or near-clear SKs with HP40 was observed in 65% of facial SKs (vs 10% VEH), 46% of truncal SKs (vs 5% VEH), and 38% of extremity SKs (vs 9% VEH). Facial SKs were more likely to be clear or near clear after a single treatment (43%), versus SKs on the trunk (31%) or extremities (14%). Most common immediate reactions with HP40 were erythema, stinging, and edema, which resolved to none or mostly mild within a week. Delayed reactions such as dyspigmentation and scarring occurred at low rates and were least reported for the facial SKs. Conclusions: SK clearance with HP40 was highest among SKs on the face and lowest among SKs on the extremities. Dyspigmentation rates were lowest among SKs treated on the face. Anatomic location of SK was a predictor of both treatment response and risk of dyspigmentation with HP40 application.