Characterization and treatment outcomes of rituximab therapy in super-responders and rituximab-refractory pemphigus patients: A single-center retrospective study.

Abstract

Rituximab (RTX) is a first-line treatment for pemphigus, yet responses vary. Standardized definitions for super-responder (SR) and rituximab-refractory patient (RRP) are lacking, and their predictive factors remain unclear. To establish definitions for SR and RRP, compare their baseline characteristics, identify predictive factors, and evaluate the safety profile of RTX treatment over 48 weeks. This retrospective study analyzed baseline data from patients with pemphigus receiving initial RTX. Univariate and multivariate logistic regression identified independent predictors for SR and RRP. Of 205 patients, 61 (29.8%) were SRs, 55 (26.8%) RRPs, and 89 (43.4%) moderate responders. Independent predictors for SRs were lower baseline Pemphigus Disease Area Index, higher baseline B-cell percentage, and negative direct immunofluorescence for C3. For RRPs, independent predictors were higher initial dose of corticosteroids and history of prior immunosuppressants use. The overall incidence of Treatment-emergent adverse events (TEAEs) within 48 weeks was 29.3%, primarily cutaneous/mucosal infections, with no significant difference among groups. Single center design and limited sample size. This study proposes practical definitions for SR and RRP in RTX-treated pemphigus and identifies distinct, readily obtainable baseline predictors, which may facilitate early identification of patients with differing treatment responses, providing personalized treatment strategies.