Adjuvant rituximab therapy of pemphigus a single-center experience with 31 patients

Background: We conducted a retrospective study of patients with pemphigus vulgaris (n=24) and foliaceus (n=7) treated with adjuvant rituximab to determine efficacy and adverse events. The end point for efficacy was complete remission of disease taking no or minimal therapy. Observations: Eighteen patients (58%) achieved the study end point. Of these, 13 patients achieved complete remission off systemic therapy. Patients achieving the study end point had a median disease duration before rituximab therapy of 19 months vs 86 months in those not achieving the end point (P=.01). For the 18 patients achieving the end point, the median (SD) duration of remission was 19 (2) months. Eight of these 18 patients (44%) relapsed from 6 to 17 months after treatment. Serious adverse events attributed to rituximab treatment (osteomyelitis or phlegmon) occurred in 2 patients (6%). In paired serum samples from 10 patients before and after rituximab treatment, the percent change in serum desmoglein index value (median, -80%) was unrelated to the percent change in pneumococcal antibodies (median, +8%) (Spearman rank correlation coefficient r=-0.2). Conclusions: Patients treated with rituximab earlier in the course of disease may have better outcomes. A discussion of rituximab's mechanism of action supports the rationale for early therapy. Prospective clinical studies are necessary to substantiate this observation.