REAL-WORLD EFFECTIVENESS AND SAFETY OF RITUXIMAB IN MODERATE-TO-SEVERE PEMPHIGUS VULGARIS: A PROSPECTIVE COHORT STUDY OF 61 IRAQI PATIENTS

Abstract

Background: Pemphigus vulgaris (PV) is a chronic and potentially life-threatening autoimmune blistering disease characterized by intraepidermal acantholysis, and its prevalence is relatively high among the Iraqi population. Rituximab, an anti-CD20 monoclonal antibody, is currently recommended as the first-line therapy for moderate-to-severe PV; however, its use in Iraq remains limited.

Objective: To evaluate the clinical efficacy and safety of rituximab in patients with moderate-to-severe PV.

Methods: This prospective cohort study included 61 patients with moderate-to-severe PV at Morjan Teaching Hospital between January 2022 and December 2024. Rituximab was administered as four intravenous infusions of 500 mg at 2-week intervals. The primary outcome was complete remission off systemic therapy at 12 months. Secondary outcomes included relapse-free survival over 36 months, cumulative corticosteroid exposure, adverse events, and changes in antidesmoglein 1 and 3 autoantibody titers. Clinical activity, serological markers, and quality of life were assessed at predefined intervals.

Results: Complete remission off therapy at 12 months was achieved in 39 patients (63.9%). The median relapse-free survival was 19 months, and 47.5% of patients remained in remission at 36 months. Antidesmoglein 1 and 3 antibody levels were significantly reduced (p < 0.001). No serious adverse events or deaths were reported. Mild infusion-related reactions occurred in 11.5% of the patients. The 3-year cumulative corticosteroid dose was significantly reduced, confirming a steroid-sparing effect.

Conclusions: Rituximab demonstrated high efficacy and a favorable safety profile in Iraqi patients with moderate-to-severe PV, including those with refractory disease. Although high rates of short-term remission were achieved, long-term relapse remains a concern, highlighting the need for maintenance strategies to optimize sustained disease control.