Halobetasol 0.01% Lotion in the Treatment of Moderate-to-Severe Plaque Psoriasis of the Lower Extremities

Background: Psoriasis is a chronic, immune-mediated disease that varies widely in its clinical expression. Topical corticosteroids (TCS) are the mainstay of treatment. Long-term safety remains a concern, limiting use, and posttreatment flare is common. Recently data were reported on the use of halobetasol propionate (HP) 0.01% lotion in moderate or severe localized plaque psoriasis, once-daily for 8 weeks. In addition, a 2-week label-restricted study reported comparable efficacy to HP 0.05% cream. Data evaluating efficacy in specific locations has not been reported and while psoriasis commonly affects lower extremities treatment can be more problematic and burden of disease heightened. Objective: To investigate the efficacy of a once-daily application of HP 0.01% lotion in comparison with its vehicle in patients with moderate-to-severe plaque psoriasis of the lower extremities. Methods: A post hoc analysis of two multicenter, randomized, double-blind, vehicle-controlled phase 3 studies in moderate or severe psoriasis. Subjects (N=234) where the leg was identified as the target lesion were randomized (2:1 ratio) to receive HP 0.01% lotion or vehicle, once-daily for 8 weeks. Efficacy assessments included treatment success (defined as at least a 2-grade improvement from baseline) in each individual sign of psoriasis (erythema, plaque elevation, and scaling) at the target lesion (leg) and overall treatment outcomes including at least a 2-grade improvement from baseline in the Investigator Global Assessment (IGA) score, and ‘clear’ or ‘almost clear’, improvement in Body Surface Area (BSA) and reduction in IGAxBSA. Quality of Life (QoL) was assessed using the Dermatology Life Quality Index (DLQI) at baseline, week 4, 8, and 12. Results: At the end of the 8-week treatment period, more than half of subjects had achieved treatment success, with 52.1%, 55.5%, and 58.2% of subjects achieving at least a 2-grade reduction in erythema, plaque elevation and scaling severity on the leg, compared with 15.7% and 22.9%, and 22.2% of those treated with vehicle (P<0.001). In addition, overall treatment success (IGA) was achieved in 37.1% of these subjects who had been treated with HP 0.01% lotion compared with 8.4% treated with vehicle (P<0.001); with a corresponding 34.2% reduction in baseline BSA and 50.5% change in mean baseline IGAxBSA (both P<0.001 versus vehicle). Overall, a clinically relevant improvement in QoL was achieved by week 4; by week 8 37.7% of subjects where the leg was the target lesion had a clinically meaningful improvement in disease severity (IGAxBSA-75). Conclusions: In conclusion, halobetasol propionate 0.01% lotion provides statistically significant efficacy following 8 weeks’ therapy compared with vehicle in subjects where the leg was identified as the target lesion, with clinically relevant improvements in QoL and more than a third of subjects achieving a clinically meaningful result. J Drugs Dermatol. 2019;18(10):1029-1036.