A phase II study of gemcitabine in patients with relapsed or refractory low-grade non-Hodgkin lymphoma.

PURPOSE: The purpose of this study was to determine the tolerability, clinical response rate, and time to disease progression of gemcitabine treatment in patients with low-grade non-Hodgkin lymphoma. (NHL) PATIENTS AND METHODS: Twenty patients with low-grade NHL and progression of disease after at least 1 prior treatment regimen were prospectively enrolled. The treatment regimen consisted of 1200 mg/m2 gemcitabine intravenously administered weekly for 7 weeks followed by a 1-week rest. Subsequent treatment was given weekly for 3 weeks followed by a 1-week rest and repeated for a maximal treatment of 6 cycles until disease progression or unacceptable toxicity. RESULTS: The predominant histologic subtypes among our patients were small lymphocytic (8 of 20) and follicular (7 of 20). Grade III/IV hematologic toxicity was observed in 15 of 20 patients and dose reductions or treatment delays occurred in 19 of 20 patients. Fatigue and asthenia were treatment-limiting in many patients. There were no complete or partial responses observed and only 2 patients had stable disease after 12 weeks of treatment. The average time to progression or off-study status was 2.3 months (95% confidence interval, 1.7-2.9) with 8 patients showing progression of disease. Twelve patients were taken off the study as a result of unacceptable toxicity before observed progression of disease. No patient completed the planned course of therapy. With a median follow up of 10.2 months, 10 of 20 patients remained alive. CONCLUSION: Gemcitabine as a single agent, in this dosage and schedule, has minimal clinical activity in relapsed or refractory low-grade lymphomas and was associated with considerable toxicity. Therefore, further study of gemcitabine in this setting is not justified.

Phase II trial of individualized rituximab dosing for patients with CD20-positive lymphoproliferative disorders.

PURPOSE: To determine the feasibility and efficacy of pharmacokinetic (PK) -based maintenance dosing of rituximab and possibly design a more rational maintenance schedule. PATIENTS AND METHODS: Patients with CD20-positive lymphoproliferative disorders were treated with four weekly infusions of rituximab 375 mg/m(2). All patients without progressive disease were then monitored for 1 year and received a single infusion of 375 mg/m(2) when the level decreased below 25 microg/mL. RESULTS: Twenty-nine of 31 patients were assessable with a variety of histologic subtypes. The overall response rate (ORR) for the entire group was 59% with 27% complete responses (CRs) and 32% partial responses. The median PFS for all patients was 19 months, with a median follow-up of 25 months. In 22 patients with low-grade non-Hodgkin's lymphoma (LGNHL), the ORR was 63% with 36% CR and median progression-free survival (PFS) has not been reached. Of 29 assessable patients, 22 were available for PK-based maintenance. The median time to repeat bolus was 5 months (range, 1 to 9 months) for the first, 3.5 months (range, 2 to 5 months) for the second, and 3 months (range, 2 to 4 months) for the third infusion. Ninety-five percent of patients required three or fewer infusions to be maintained in the therapeutic range. CONCLUSION: Individualized PK dosing for rituximab produced efficacy comparable to other published maintenance strategies. PK data from this trial suggest that a rational maintenance strategy in patients with LGNHL would be a single dose of 375 mg/m(2) of rituximab every 3 to 4 months.