Long-term efficacy and safety analysis of single cycle of biosimilar rituximab in pemphigus: A retrospective study of 76 patients from India.

Pemphigus poses a therapeutic challenge and rituximab is increasingly used in its treatment. Long-term data regarding efficacy and safety of rituximab in pemphigus is limited. This study was a retrospective analysis of 76 pemphigus patients with primary endpoint being the percentage of patients achieving complete remission (CR) on/off therapy. Secondary endpoints were time to relapse, mean cumulative dose of prednisolone after rituximab infusion, mean duration of follow up, and adverse events to rituximab if any. A total of 62 (82.7%) attained complete remission on/off treatment, out of which 42 were off therapy. Mean interval between rituximab administration and complete remission off treatment was 6.9 ± 3.7 months. Complete remission off treatment was sustained for a mean duration of 21.4 ± 17.8 months before relapse. Over a mean follow-up duration of 42.7 ± 24.9 months (median 41, maximum 83 months), 22 of 62 patients (35.5%) who had achieved complete remission after the first cycle of rituximab relapsed. A mean total cumulative dose of 8716.3 ± 10533.8 mg prednisolone was prescribed over a mean duration of 18.05 ± 15.64 months after the first cycle of rituximab. Adverse events were noted in 18 out of 76 patients (23.7%) which included infusion reactions (n = 3), minor infections (n = 7), transitory disease flare (n = 6), and mortality (n = 2). No statistically significant correlation was found between remission/relapse rates and age, gender or pemphigus subtype. This study substantiates the long-term efficacy and safety of single cycle of rituximab in pemphigus.