Rituximab as first-line systemic therapy for patients with low-grade lymphoma.

Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA and IDEC Pharmaceutical Corporation, San Diego, CA), the first monoclonal antibody available for the systemic treatment of cancer, yields a 48% response rate in patients with refractory low-grade non-Hodgkin's lymphoma. This preliminary report describes the use of rituximab, instead of standard chemotherapy, in 39 previously untreated patients with stages II-IV low-grade non-Hodgkin's lymphoma All patients received rituximab 375 mg/m2 by intravenous infusion for 4 consecutive weeks and were evaluated for response at week 6. Patients with stable disease or an objective response received repeat 4-week courses at 6-month intervals, for a maximum of four treatment cycles. At initial evaluation for response at week 6, 21 of 39 patients (54%) had objective responses and 14 (36%) had stable disease or a minor response. Response rates were similar in patients with follicular and small lymphocytic lymphoma (52% v 57%, respectively). Seven additional responses were reported either before or after the second course. Currently, the overall response rate is 72%, with 18% complete responses. The progression-free survival rate at 1 year is 77%. Treatment was well tolerated. The high level of activity suggests that initial treatment with rituximab is a reasonable option in this group of patients, and that repeat maintenance courses at 6-month intervals are feasible and well tolerated. Further follow-up evaluation is necessary to determine the merits of this approach compared with traditional chemotherapeutic treatment.