Abstract
BACKGROUND: Psoriasis is a chronic inflammatory skin disease associated with quality of life (QoL) impairment. BRIDGE was a randomized, double-blind, phase III study comparing the efficacy and safety of dimethylfumarate (DMF) with a fixed combination of fumaric acid esters (FAE) or placebo for the treatment of moderate-to-severe psoriasis. OBJECTIVES: This post hoc analysis investigated treatment effect on QoL overall and by patient subgroups categorized by disease severity. Week 8 efficacy responses were also investigated as possible predictors of Week 16 Dermatology Life Quality Index (DLQI) outcomes. METHODS: Patients were randomized to receive a maximum daily dose of 720 mg of DMF, FAE (gradual up-titration) or placebo for 16 weeks. Psoriasis Area Severity Index, Body Surface Area, Physician's Global Assessment and DLQI were assessed at baseline, Weeks 8 and 16. DLQI 0-1 indicated 'no effect on patient life'. Associations between baseline severity, Week 16 DLQI and Week 8 efficacy (as observed cases) were also examined. RESULTS: At baseline, 671 patients were included in the full analysis set (267 randomized to DMF, 273 to FAE and 131 to placebo). DMF was superior to placebo (P < 0.001) and not significantly different to FAE regarding Week 16 DLQI outcomes (P > 0.05). Baseline disease severity did not impact DLQI outcomes at Week 16. In DMF- and FAE-treated patients, Week 8 PASI 50/75 responders reported better DLQI responses at Week 16 vs non-responders (P < 0.05). Week 8 PASI ≤ 3 and/or PGA 0-1 responders were also more likely to report DLQI 0-1 at Week 16 vs non-responders (P < 0.05). CONCLUSION: Dimethylfumarate significantly improved DLQI outcomes vs. placebo and was not affected by baseline disease severity. Efficacy responses (PASI 50/75, PASI ≤3 and PGA 0-1) as early as Week 8 were predictive of QoL outcomes at Week 16 in DMF- and FAE-treated patients.