Comparison of various protocols and dosage schedules of rituximab used by various researchers in pemphigus: A review article

Objective: To compare the effectiveness of various protocols available in literature, dose, schedules, and the side effect profile of rituximab in pemphigus (vulgaris and foliaceus) patients. Materials and Methods: Publications related to treatment with rituximab in pemphigus were identified by searches of electronic databases in PubMed from January 2002 to June 2023. A total of 43 papers, which included 35 case series and retrospective studies, four randomized control trials, and four open-label pilot studies, were analyzed, and a narrative review of the studies was presented. Results: There are a total of 13 different protocols by which the rituximab infusion has been given. The most common is the rheumatoid arthritis (RA) protocol (53.4%) followed by the lymphoma protocol (15.5%) and low-dose RA protocol (7.4%). Low-dose RA protocol showed complete remission (CR)—82.6%, relapse rate (RR)—20.4%, duration of remission (DOR)—75.95 weeks, and time to relapse—76.35 weeks, while with RA protocol, CR was seen in 78.3% patients with RR being 28.57%, DOR—79.96 weeks and time to relapse—78.38 weeks. In lymphoma protocol, we noticed CR in 66.7% of patients with RR of 32.1% while the time to relapse is 63.3 weeks. Conclusion: We have observed good results with RA protocol and low-dose RA protocol than other regimens of rituximab used to treat pemphigus vulgaris and foliaceus. However, there is a need for a multicentric trial on a large scale for detecting the effective dose of rituximab depending upon the severity of the pemphigus and will help to lay down effective protocol for induction and maintenance of disease-free period, as there are no country-specific guidelines available for the Indian subcontinent.