Abstract
INTRODUCTION: The phase 3 PSO LONG study (NCT02899962) demonstrated superior efficacy of proactive (PM) versus reactive management (RM) using calcipotriene 0.005%/betamethasone dipropionate 0.064% (Cal/BD) foam in adults with psoriasis. Here, we evaluated whether certain baseline parameters had an effect on time to first relapse (TTFR), number of relapses, and assessed interactions between treatment effect. METHODS: PSO LONG included an initial 4-week open-label phase (once-daily Cal/BD foam) and a 52-week maintenance phase where patients were randomized to twice-weekly Cal/BD (PM) or vehicle foam (RM), with a 4-week once-daily Cal/BD foam rescue treatment for relapse. Baseline parameters analyzed using a stepwise variable selection procedure included body surface area, modified Psoriasis Area Severity Index (mPASI), Physician Global Assessment (PGA), body mass index, age, sex, Dermatology Life Quality Index, and duration of psoriasis. Continuous variables were divided into groups based on standard criteria. RESULTS: Overall, the effect of treatment on TTFR did not vary across any baseline parameters. Variables with a statistically significant effect on TTFR were: treatment group (PM vs. RM hazard ratio [HR]: 0.56; p < 0.001); PGA (moderate vs. mild HR: 1.42; severe vs. mild HR: 2.32; overall p = 0.009); mPASI (moderate vs. mild HR: 1.19; severe vs. mild HR: 1.77; overall p = 0.009); and sex (women vs. men HR: 1.26; p = 0.030). Variables with a significant effect on the number of relapses were: treatment group (PM vs. RM, rate ratio [RR] 0.52; p < 0.001); PGA at baseline (moderate vs. mild, RR 1.38; severe vs. mild, RR 2.22; overall p < 0.001); and mPASI (moderate vs. mild, RR 1.25; severe vs. mild, HR 1.70; overall p = 0.002). CONCLUSION: All patients benefitted from long-term PM versus RM with Cal/BD foam regardless of baseline characteristics, and the benefit of treatment increased with greater disease severity. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02899962.