CLINICAL OBSERVATIONS, INTERVENTIONS, AND THERAPEUTIC TRIALS Prolonged treatment with rituximab in patients with follicular lymphoma significantly increases event-free survival and response duration compared with the standard weekly 4 schedule

The potential benefits of extended rituximab treatment have been investigated in a randomized trial comparing the standard schedule with prolonged treatment in 202 patients with newly diagnosed or refractory/relapsed follicular lymphoma (FL). All patients received standard treatment (rituximab 375 mg/m2 weekly 4). In 185 evaluable patients, the overall response rate was 67% in chemotherapynaive patients and 46% in pretreated cases (P < .01). Patients responding or with stable disease at week 12 (n 151) were randomized to no further treatment or prolonged rituximab administration (375 mg/m2 every 2 months for 4 times). At a median follow-up of 35 months, the median event-free survival (EFS) was 12 months in the no further treatment versus 23 months in the prolonged treatment arm (P .02), the difference being particularly notable in chemotherapy-naive patients (19 vs 36 months; P .009) and in patients responding to induction treatment (16 vs 36 months; P .004). The number of t(14;18)–positive cells in peripheral blood (P .0035) and in bone marrow (P .0052) at baseline was predictive for clinical response. Circulating normal B lymphocytes and immunoglobulin M (IgM) plasma levels decreased for a significantly longer time after prolonged treatment, but the incidence of adverse events was not increased. In patients with FL, the administration of 4 additional doses of rituximab at 8-week intervals significantly improves the EFS. (Blood. 2004;103:4416-4423)