PRO68 Patient-Reported Outcomes in Patients with Pemphigus Vulgaris Treated with Rituximab in the Phase 3 PEMPHIX Study

Abstract

Rituximab is approved for the treatment of moderate to severe pemphigus vulgaris (PV), a rare autoimmune blistering disease. A phase 3 randomized, double-blind, double-dummy study (PEMPHIX, NCT02383589) demonstrated that rituximab is superior to mycophenolate mofetil (MMF) in achieving complete remission off corticosteroids for ≥16 consecutive weeks. Evaluation of patient-reported outcomes in PEMPHIX are reported herein. Patients with moderate-to-severe PV were randomized to intravenous rituximab (1000mg on Days 1, 15, 168, and 182) or oral MMF (2g/day) in combination with a tapering course of oral prednisone for 52 weeks. Secondary endpoints included health-related quality of life (HRQoL) as measured by the Dermatology Life Quality Index (DLQI). Exploratory endpoints included PV symptoms as measured by the Skindex-29 and Patient Global Impression of Change (PGIC) in PV symptoms. At Week 52 from baseline, mean change in DLQI score for rituximab patients was -8.87 vs. -6.00 for MMF patients (P=0.0012). In a post-hoc analysis, 61.7% of rituximab and 25.0% of MMF patients achieved a DLQI score of 0, indicating no impact on HRQoL. Mean changes in Skindex-29 Symptoms domain were -37.06 for rituximab patients vs. -18.35 for MMF patients, P<0.0001; Emotions domain -30.23 vs. -13.69, P=0.0003; and Functioning domain -33.73 vs. -19.36, P=0.0003. As measured by PGIC, 100% of rituximab and 89.3% of MMF patients reported improvement in their PV symptoms, with 80.9% of rituximab-treated patients reporting that their PV symptoms had “very much improved” compared with 39.3% of MMF-treated patients (P=0.0021). Significantly greater improvements in HRQoL as measured by the DLQI were observed in patients treated with rituximab compared with MMF, and more patients treated with rituximab reported no impairment in HRQoL compared with MMF. Rituximab treatment also led to greater improvements in PV symptoms. These patient-reported outcomes support the positive benefit-risk profile of rituximab use in PV.