SOUTH SAN FRANCISCOThe FDA has approved a supplemental
biological license application (sBLA) for Rituxan (rituximab), the monoclonal
antibody developed by Genentech, Inc. and IDEC Pharmaceuticals (San Diego) for
treatment of patient with relapsed or refractory, low-grade or follicular,
CD20-positive, B-cell non-Hodgkin’s lymphoma (NHL). The new product labeling
includes re-treatment with rituximab after a prior course, initial treatment
with eight weekly infusions instead of four, and treatment of bulky disease.
In a phase II multicenter single-arm study, 60 NHL patients
were re-treated when they relapsed after obtaining an objective clinical
response with their initial 4-week course of rituximab once a week. The overall
response rate was 38%, with 10% achieving a complete response. The projected
median duration of response is 15 months.
In another phase II multicenter single-arm study, 37 NHL
patients received 375 mg/m2 of rituximab once a week for a total of
eight weekly infusions. The overall response rate was 57% (14% complete
responses). The projected median response duration is 13.4 months.
Results also were submitted from multiple rituximab studies of
39 low-grade NHL patients with relapsed or refractory bulky disease. The
overall response rate was 36%, with 3% achieving a complete response. The
median duration of response was 6.9 months. Each patient received 375 mg/m2
of rituximab in four weekly infusions.
In addition, the revised package insert will emphasize already
existing safety information concerning rare severe and potentially fatal
mucocutaneous reactions that have occurred in patients who have received
Patients experiencing these reactions have highly compromised
immune systems related to their disease, the companies said. Currently, there
has been no direct link made between these types of reactions and rituximab
use. However, until more is known, it is important that physicians understand
that rituximab could have contributed to some of these events and manage their