Low-dose rituximab is effective in pemphigus

Authors


  • Funding sources
    None.

  • Conflicts of interest
    None declared.

Barbara Horváth.
E-mail: b.horvath@umcg.nl

Summary

Background  Rituximab, an anti-CD20 antibody, was shown in open series studies to be effective in treating pemphigus at a dose of 4 × 375 mg m−2 as approved for B-cell malignancies.

Objectives  We investigated whether a lower dose of rituximab is also effective for pemphigus.

Methods  Patients with pemphigus were treated with a single course of two infusions of rituximab (500 mg each) at an interval of 2 weeks. Clinical consensus late end points, B-cell number, desmoglein 1 and desmoglein 3 indices were monitored.

Results  We enrolled 15 patients in the study: three with pemphigus foliaceus (PF) and 12 with pemphigus vulgaris (PV). The follow-up was 32–152 weeks (median 94). All 15 patients responded to therapy. Eight patients achieved complete remission in a median period of 51 weeks (four on minimal therapy, four off therapy). Seven patients achieved partial remission in a median period of 34·5 weeks (five on minimal therapy, two off therapy). Relapses (40%) were seen between 53 and 103 weeks (median 97) after start of therapy. B-cell numbers dropped to < 1% after first infusion, and remained undetectable in patients with sustained remission. The antidesmoglein 1 index correlated well with the clinical severity in PF, but this was less obvious in PV.

Conclusions  A low dose of rituximab is an effective and safe treatment for pemphigus. Relapses may occur, mostly at the end of the second year. Cost–effectiveness studies with a long follow-up are required to determine the proper dosage of this expensive drug in pemphigus.

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