Temporal Outcomes after Rituximab Therapy for Pemphigus Vulgaris

Pemphigus vulgaris is an autoimmune blistering disease characterized by autoantibodies that target desmoglein adhesion proteins. Rituximab and corticosteroids are Food and Drug Administration‒approved therapies for pemphigus vulgaris. As newer treatments for pemphigus enter clinical trials, analysis of clinical and serologic outcomes after rituximab therapy as a function of time is essential to guide clinical trial design. In this study, we report detailed temporal and serologic outcomes of rituximab treatment of pemphigus vulgaris. The maximal prevalence of complete remission off oral systemic therapy after a single cycle of rituximab was 32.4% at 12 months or 43.1% by 36 months, including additional rituximab cycles. Using receiver operating characteristic curves to develop prediction models for complete remission after a single cycle of rituximab, >90.7% reduction in average desmoglein 3 ELISA titers from baseline to months 3‒9 was 94% sensitive, and an average absolute titer ≤130 RU/ml between months 3 and 9 was 96% specific, for achievement of complete remission off oral systemic therapy. All patients with negative titers at 6‒9 months ultimately achieved complete remission off oral systemic therapy. This dataset of clinical and serologic outcomes for patients with pemphigus vulgaris after rituximab therapy will facilitate clinical trial planning and also guide clinician and patient expectations after rituximab therapy.