Halobetasol and tazarotene: Further defining the role of a unique fixed combination topical lotion in moderate-to-severe plaque psoriasis

Background: A unique fixed combination halobetasol propionate 0.01% and tazarotene 0.045% (HP/TAZ) lotion has been shown to be effective in psoriasis using Investigator Global Assessment (IGA) tools to assess erythema, plaque elevation, and scaling. However, these do not consider changes in Body Surface Area (BSA). The IGAxBSA composite tool is a simple, effective, validated alternative for measuring improvement in psoriasis severity. It correlates well with the Psoriasis Area and Severity Index (PASI) and demonstrates sensitivity to changes from baseline in patients with both mild and moderately severe disease. Objective: To further define the role of a fixed combination halobetasol propionate 0.01% and tazarotene 0.045% (HP/TAZ) lotion in moderate-to-severe plaque psoriasis using the IGAxBSA composite tool. Methods: Post hoc analysis of 212 patients with moderate-to-severe plaque psoriasis randomized (2:2:2:1) to HP/TAZ lotion, HP, TAZ, or vehicle once-daily for 8 weeks, with a 4-week posttreatment follow-up. Efficacy assessments using the validated IGAxBSA composite tool. Results: HP/TAZ lotion demonstrated statistically significant superiority at week 8 (versus TAZ and vehicle) and week 12 (versus HP, TAZ, and vehicle). By week 8, HP/TAZ lotion achieved a 63.5% reduction in mean IGAxBSA composite score (P<0.001 versus TAZ and vehicle), that was sustained four weeks posttreatment (P<0.001 versus TAZ and vehicle and P=0.003 versus HP). A 25% and 50% improvement in IGAxBSA was achieved within 1.9 and 4.6 weeks, respectively, and 47.5% of patients achieved IGAxBSA-75 by week 8. Limitations: This post hoc analysis was limited to patients with moderate-to-severe plaque psoriasis with IGA ≥3 and BSA involvement (3%-12%). Conclusions: HP/TAZ lotion was associated with significant and rapid reductions in disease severity as assessed by the IGAxBSA composite tool. The addition of tazarotene affords sustained benefits posttreatment.