P118 A retrospective analysis of rituximab prescribing for 38 patients with pemphigus over a 10-year period in a tertiary immunobullous clinic: should we be using rituximab as first-line therapy for moderate and severe pemphigus?

Abstract Pemphigus encompasses a rare group of autoimmune bullous diseases characterized by blisters and erosions of the skin and mucosal membranes. Rituximab, an anti-CD20 chimeric monoclonal antibody that reduces circulating B cells, is an effective treatment for pemphigus. Its use as a first-line agent is now part of both the European Union and US guidelines, but commissioning criteria set out by National Health Service England consider rituximab as a third-line treatment for this condition. There is growing evidence that delayed prescription of rituximab can prolong time to disease remission and worsen disease-associated morbidity. We report a retrospect analysis of 38 patients with pemphigus vulgaris (PV) and pemphigus foliaceus (PF) prescribed rituximab from 2014 to 2024 in a single tertiary centre. Overall, 86% (n = 33) had PV and 14% (n = 5) had PF. Our cohort included 20 male and 18 female patients, and the age at diagnosis ranged from 23 to 84 years. Diagnosis was with histopathology, direct immunofluorescence and serology, including indirect immunofluorescence and/or enzyme-linked immunosorbent assay (desmogleins 1 and 3). All patients received prednisolone, ranging from 0.5 mg kg−1 to 1 mg kg−1. Second-line treatment was with mycophenolate mofetil in 76% (n = 29), azathioprine in 7% (n = 3) and dapsone in 5% (n = 2). Third-line treatments included azathioprine, dapsone and methotrexate. Patients received an average of 2.3 treatment modalities before rituximab. The interval between diagnosis and commencing rituximab varied between 1 month and 6 years, with patients diagnosed more recently tending to start rituximab sooner. Rituximab was administered as two doses of 1 g spaced 14 days apart. Complete remission was achieved by 52% (n = 20) of patients 6 months after starting rituximab. Of these, 85% were still taking prednisone and/or mycophenolate mofetil at 6 months, with further reduction and cessation of these medications documented over a longer timeframe. Partial remission was achieved by 42% (n = 16) 6 months after rituximab. Ten patients relapsed and required a second treatment with rituximab. The interval between the initial rituximab and disease relapse in these patients was 1–5 years. Three patients were treated with a third course of rituximab and one patient required a fourth course. Patients given rituximab at a later stage in their disease had a higher cumulative dose of prednisolone. The patients requiring multiple courses of rituximab or taking longer to achieve complete remission had a longer duration between diagnosis and initial rituximab treatment. Our real clinic findings highlight the management of patients with severe or recalcitrant pemphigus. The results are corroborated by the increasing body of convincing medical evidence suggesting that earlier administration of rituximab for pemphigus is both safer and more efficacious than standard therapy and make a case for earlier use of rituximab in this challenging cohort.