The Food and Drug Administration has granted breakthrough therapy status to rituximab (Rituxan) for treating pemphigus vulgaris, according to the manufacturer.
Rituximab, a CD20-directed cytolytic antibody approved in 1997, is currently in a phase III study evaluating its efficacy for the pemphigus indication. It is approved in the United States for treating non-Hodgkin lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis (with methotrexate), granulomatosis with polyangiitis (Wegener’s granulomatosis), and microscopic polyangiitis (with glucocorticoids).
The patients, who were experiencing their first episode of pemphigus vulgaris, were randomized to daily oral prednisone, tapered over a 12- to 18-month period, or rituximab administered intravenously (at days 0 and 14, and months 12 and 18), plus daily oral prednisone, tapered over 3 or 6 months. At 2 years, when they were no longer on therapy, 89% of those treated with rituximab and prednisone were in complete remission, compared with 34% of those treated with prednisone alone (P less than .0001).
The breakthrough therapy process is “designed to expedite the development and review of drugs that are intended to treat a serious condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint(s),” according to the FDA.
The study was supported by the French Ministry of Health, the French Society of Dermatology, and Roche, which owns Genentech. Genentech markets rituximab in the United States with Biogen and is conducting the phase III study.