Complete remission after rituximab therapy of pemphigus: Real-world evidence on dosing regimens and re-treatment strategies

Although rituximab is clinically-approved for pemphigus, real-world data on predictors of treatment success and optimal dosing remain limited. We conducted a retrospective cohort study at NewYork-Presbyterian Hospital of pemphigus patients treated with rituximab with ≥1 year of follow-up. Patients initially received two 1,000 mg doses 2 weeks apart or four weekly weight-adjusted (375 mg/m 2 ) infusions. Factors associated with complete remission off oral immunosuppressive therapy were analyzed using Kaplan-Meier and Cox proportional hazards analyses. Among 105 patients, 44.7% achieved complete remission off therapy after the first rituximab cycle, increasing to 74.3% after multiple cycles with median time to remission of 7.4 months. Weight-adjusted rituximab dosing was associated with a higher likelihood of achieving CROT after the first rituximab cycle compared with the fixed-dose regimen (hazard ratio 2.49, p=0.01). For subsequent treatment, maintenance rituximab infusions every 6 months was associated with shorter time to initial achievement of complete remission off therapy and longer time to relapse compared with an on-demand approach; however, both achieved similar overall rates of complete remission off therapy. These findings support the benefit of weight-adjusted dosing for the first rituximab cycle and provide real-world data on outcomes of maintenance versus on-demand rituximab infusions for pemphigus therapy.