Safety and Efficacy of a Fixed Combination Halobetasol and Tazarotene Lotion in the Treatment of Moderate-to-Severe Plaque Psoriasis: A Pooled Analysis of Two Phase 3 Studies
August 2018 | Volume 17 | Issue 8 | Original Article | 855 | Copyright © August 2018
Jeffrey L. Sugarman MD PhD,a Jonathan Weiss MD,b Emil A. Tanghetti MD,c Jerry Bagel MD,d Paul S. Yamauchi MD,e Linda Stein Gold MD,f Tina Lin, PharmD,g Gina Martin MOT,h Radhakrishnan Pillai PhD,h Robert Israel MDi
aUniversity of California, San Francisco, CA bGwinnett Dermatology, PC, and Gwinnett Clinical Research Center, Inc, Snellville, GA cCenter for Dermatology and Laser Surgery, Sacramento, CA dPsoriasis Treatment Center of Central New Jersey, East Windsor, NJ eDavid Geffen School of Medicine at UCLA, Los Angeles, CA fHenry Ford Hospital, Detroit, MI gOrtho Dermatologics, Bridgewater, NJ hDow Pharmaceutical Sciences Inc. (a division of Valeant Pharmaceuticals, North America, LLC.), Petaluma, CA iBausch Health, Bridgewater, NJ
Here we further investigate the safety and tolerability of HP/TAZ lotion, reporting on the pooled data from two phase 3 clinical studies.
Two multicenter, double-blind, randomized, parallel-group phase 3 studies to assess the safety, tolerability and efficacy of ahalobetasol propionate 0.01%/tazarotene 0.045% (HP/TAZ) fixed combination lotion in subjects with a clinical diagnosis of moderate-to-severe psoriasis (with an Investigator Global Assessment [IGA] score of 3 or 4, and an affected body surface area [BSA] of 3% to 12%). Subjects were randomized (2:1) to receive HP/TAZ lotion or vehicle applied topically to the affected area once-daily for 8 weeks.
Inclusion and Exclusion Criteria
Key inclusion criteria included subjects of either gender, 18 years or older. A target lesion, defined primarily to assess signs of psoriasis, measuring 16-100 cm2; with a score of ≥3 for two of the three different psoriasis signs (erythema, plaque elevation, and scaling), and summed score of ≥8, with no sign scoring
Subjects provided written informed consent before study-related procedures were performed, and the protocol and consentwere approved by institutional review boards (IRBs) or ethics committees at all investigational sites. The study was conducted in accordance with the principles of Good Clinical Practice (GCP) and the Declaration of Helsinki.
The key efficacy endpoint was the percent of subjects who were treatment successes at week 8; defined as those with at least a 2-grade improvement in their baseline IGA score, and a score equating to “clear” or “almost clear” (ie, 0 or 1). A 5-point scale ranging from 0 (clear) to 4 (severe) was used by the investigator at each study visit to assess the severity of overall psoriasis of the treatable areas. Treatment success was also evaluated at weeks 2, 4, 6, and week 12 (4-week post-treatment follow-up) to provide additional efficacy data.Signs of psoriasis at the target lesion were assessed at each visit using individual 5-point scales ranging from ranging from 0 (clear) to 4 (severe). Here treatment success was defined as those subjects with at least a 2-grade improvement from baseline score for each of the key signs (erythema, plaque elevation, and scaling). Affected BSA was also assessed at each visit.
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 were also examined by the investigator at each visit for presence/absence of significant known drug-related AEs; skin atrophy, striae, telangiectasia, and folliculitis.
Local Skin Reaction Assessment
Local skin reactions (LSRs) 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.
Statistical and Analytical Plan
The primary study goal was to assess treatment effect differences between HP/TAZ lotion and vehicle with respect to IGA. Allstatistical processing was performed using SAS® unless otherwise stated; statistical tests were two-sided and performed at the 0.05 level of significance. Markov Chain Monte Carlo (MCMC) multiple imputation was the primary method used to handlemissing efficacy data. No imputations were made for missing safety data.All subjects randomized, and dispensed study drug were included in the intent-to-treat (ITT) analysis set. This analysis was considered primary for the evaluation of efficacy. Data were analyzed using Cochran-Mantel-Haenszel (CMH) tests, stratified by analysis center. BSA data were analysed in a post-hoc analysis of covariance (ANCOVA) with factors of treatment and analysis