Successful treatment of pemphigus with biweekly 1-g infusions of rituximab: A retrospective study of 47 patients

Background: Rituximab is increasingly being appreciated as a remarkably effective treatment for pemphigus, mostly concomitantly with other immunosuppressive medications. The majority of studies have used a single cycle of rituximab with the same dosage as approved for the treatment of lymphomas, ie, 375 mg/m(2) weekly x 4 weeks. Rituximab is also approved for the treatment of rheumatoid arthritis, with a different dosing regimen: 1000 mg x 2, days 1 and 15. Objective: We aimed to assess the clinical response of patients with pemphigus to a single cycle of rituximab at the dosage used in rheumatoid arthritis. We also evaluated the response to repeated cycles of rituximab. Methods: A total of 47 patients with pemphigus who were treated with rituximab at a dosage of 1000 mg x 2, days 1 and 15, most with concurrent immunosuppressive medications, were retrospectively studied. Results: Remission rates after the first treatment cycle reached 76%. Repeating the treatment further increased the remission rates to 91%. There was a 22% relapse rate at a median time of 8 months, but 75% of relapsing patients achieved remission again with additional cycles. The side-effect profile was similar to previous reports, except for an immediate postinfusion pemphigus exacerbation in 4 patients. Limitations: This was a retrospective study with a limited follow-up period. Conclusion: The rheumatoid arthritis dosage of rituximab was efficacious and well tolerated in patients with pemphigus. Patients who fail to achieve remission after 1 cycle or patients who relapse seem to benefit from repeated rituximab cycles. (J Am Acad Dermatol 2013;68:404-11.)