Effectiveness and safety analysis of rituximab in 146 Indian pemphigus patients: A retrospective single-center review of up to 68 months follow-up

Abstract

Background: Rituximab is being increasingly used for the treatment of pemphigus. Data derived from single-center studies following a uniform treatment protocol are limited. Effect of demography and disease type on treatment response is poorly characterized. Objective: Our aim was to assess the effectiveness of biosimilar rituximab in pemphigus patients who had received rituximab as per rheumatoid arthritis protocol (2 doses, 1g each, infused 14 days apart). Methods: It was a retrospective review of 146 eligible patients to assess the proportion of patients achieving complete remission off treatment, time to achieve complete remission off treatment, proportion of patients who relapsed after achieving complete remission off treatment, time taken to relapse, duration and total cumulative dose of corticosteroids administered after rituximab. Additionally, we tried to find whether a correlation existed between age, gender, total duration of illness before rituximab and pemphigus disease type with the above-mentioned outcome measures. Results: Of 146 patients, 107 (73.3%) attained complete remission off treatment. Mean interval between first dose rituximab administration and complete remission off treatment was 6.6 ± 3.4months. Complete remission off treatment was sustained for a mean duration of 9.1 ± 8.5 months before relapse. Over a mean follow-up duration of 24.9 ± 17.1 months (median 23, maximum 68 months), 75 of 107 patients (76.5%) who had achieved complete remission after first cycle of rituximab relapsed. A mean total cumulative dose of 3496 ± 2496 mg prednisolone was prescribed over a mean duration of 7.2 ± 4.7 months after first cycle of rituximab. Time taken to achieve remission was significantly longer in pemphigus foliaceus and these patients required significantly higher cumulative dose of prednisolone over a longer duration after rituximab. No deaths and long-term complications were recorded. Limitations: Only clinical parameters were assessed. Immunological parameters including B-cell counts and enzyme-linked immunosorbent assay for anti-desmoglein antibody titers were not carried out. Conclusion: This study reinforces the beneficial role of rituximab in pemphigus. Pemphigus foliaceus patients required a higher total cumulative dose of prednisolone over a longer time to achieve remission and the remission lasted longer than that in pemphigus vulgaris.