Safety and Efficacy of Halobetasol Propionate Lotion 0.01% in the Treatment of Moderate to Severe Plaque Psoriasis: A Pooled Analysis of 2 Phase 3 Studies
Potent topical corticosteroids (TCSs) are the mainstay of psoriasis treatment. Safety concerns have limited use to 2 to 4 weeks. The objective of our study was to investigate the safety and efficacy of once-daily halobetasol propionate (HP) lotion 0.01% in moderate to severe plaque psoriasis through 2 multicenter, randomized, double-blind, vehicle-controlled phase 3 studies (N=430). Participants were randomized (2:1) to HP lotion 0.01% or vehicle once daily for 8 weeks, followed by 4 weeks of follow-up. The primary efficacy assessment was treatment success (at least a 2-grade improvement in baseline investigator global assessment [IGA] score and a score of 0 [clear] or 1 [almost clear]). Additional assessments included improvement in psoriasis signs and symptoms, body surface area (BSA), and a composite score of IGA×BSA. Safety and treatment-emergent adverse events (AEs) were evaluated throughout. We found that HP lotion 0.01% demonstrated statistically significant superiority over vehicle as early as week 2 and also was superior in reducing psoriasis signs and symptoms and BSA involvement.
Inclusion and Exclusion Criteria
The studies included individuals of either sex aged 18 years or older. A target lesion was defined primarily to assess signs of psoriasis, measuring 16 to 100 cm2, with a score of 3 (moderate) or higher for 2 of 3 different psoriasis signs—erythema, plaque elevation, and scaling—and summed score of 8 or higher, with no sign scoring less than 2. Participants who had pustular psoriasis or used phototherapy, photochemotherapy, or systemic psoriasis therapy within the prior 4 weeks or biologics within the prior 3 months, or those who were diagnosed with skin conditions that would interfere with the interpretation of results were excluded from the studies.
Study Oversight
Participants provided written informed consent before study-related procedures were performed, and the protocol and consent were approved by institutional review boards or ethics committees at all investigational sites. The study was conducted in accordance with the principles of Good Clinical Practice and the Declaration of Helsinki.
Efficacy Assessment
A 5-point scale ranging from 0 (clear) to 4 (severe) was used by the investigator at each study visit to assess the overall psoriasis severity of the treatable areas. Treatment success (the percentage of participants with at least a 2-grade improvement in baseline IGA score and a score of 0 [clear] or 1 [almost clear]) was evaluated at weeks 2, 4, 6, and 8, w
Signs of psoriasis at the target lesion were assessed at each visit using individual 5-point scales ranging from 0 (clear) to 4 (severe). Treatment success was defined as at least a 2-grade improvement from baseline score for each of the key signs—erythema, plaque elevation, and scaling—and reported at weeks 2, 4, 6, and 8, with a posttreatment follow-up at week 12.
Affected BSA also was evaluated at each visit. In addition, an IGA×BSA composite score was calculated by multiplying the IGA by the BSA (range, 9–48 [eg, maximum IGA=4 and maximum BSA=12]) at each time point. The mean percentage change in IGA×BSA from baseline was calculated for each study visit. Additional end points included the achievement of a 50%, 75%, and 90% or greater reduction from baseline IGA×BSA score—IGA×BSA-50, IGA×BSA-75, and IGA×BSA-90—at week 8.
Safety Assessment
Safety evaluations including adverse events (AEs), local skin reactions (LSRs), vital signs, laboratory evaluations, and physical examinations were performed. Information on reported and observed AEs was obtained at each visit. Routine safety laboratory tests were performed at screening, week 4, and week 8. An abbreviated physical examination was performed at baseline, week 8 (end of treatment), and week 12 (end of study). Treatment areas also were examined by the investigator at baseline and each subsequent visit for the presence or absence of marked known drug-related AEs including skin atrophy, striae, telangiectasia, and folliculitis.
LSR Assessment
Local skin reactions such as itching, dryness, and burning/stinging were evaluated at each study visit using 4-point scales ranging from 0 (clear) to 3 (severe). Given the nature of the disease, the presence of LSRs and symptoms at baseline is commonplace, and as such, these evaluations identified both improvement and any emergent issues.
