Successful Treatment of Pemphigus Vulgaris with a Modified Regimen of Rituximab Biosimilar(CT-P10) Combined with IVIG

Keywords: Pemphigus vulgaris;Modified Regimen;Rituximab biosimilar; IVIG Pemphigus Vulgaris (PV) has been known as fatal autoimmune bullous diseases affecting the skin and mucous membranes. Here, we report that a patient with PV responded rapidly to a modified regimen of rituximab biosimilar (CT-10, Truxima®)combined with Intravenous Immunoglobulin (IVIG). A 53-year-old man presented with extensive erosions due to blistering on the whole body following initial mucosal erosions which started at 3 years ago. Laboratory tests revealed an eosinophil count of 16.7% (normal range: 0~5%) with normal liver and renal functions. Antinuclear antibody was a nuclear membrane pattern with a titer of 1:40. Anti-dsDNA, anti-Ro/La, anti-Scl-70, and anti-phospholipid antibodies were negative. Myeloperoxidase and PR3 antineutrophil cytoplasmic autoantibody were both negative. Histological examination showed suprabasala cantholysis, while direct and indirect immunofluorescence assays demonstrated a deposition of immunoglobulin G (IgG) on anintercellular surface at 1:640 dilutions (Figure. 1a, b). Based on the blistering on the whole body and characteristic biopsy result, the patient was diagnosed as PV. Although he was initially treated with topical and highdose methylprednisolone (1000 mg/day) pulse therapy for 3 consecutive days, there was no significant improvement in skin blistering lesions. We decided to administer CT-P10 combined with IVIG. We treated the patient with CT-P10 (500, 500, and 1000mg once weekly for 3 weeks) combined with IVIG (1g/ kg at first and third week). During the treatment of CT-P10 combined with IVIG, a clinical response rapidly appeared, and levels of antibodies were decreased from 1:640 to 1:40 (Figure. 1c). Disease activity was dramatically controlled within 3 weeks. It achieved the end of the consolidation phase for PV within 5 weeks after starting CT-P10 combined with IVIG (Figure. 1dg). Then, we tapered oral prednisolone and steroid-sparing agents including mycophenolate mofetil and cyclosporine for maintenance therapy. Until now, there has been no recurrence of PV on 36 months follow up.