Background and objective: The first clinical studies of paclitaxel as a single agent for the treatment of relapsed or refractory low or intermediate grade non-Hodgkin's lymphomas (NHL) yielded controversial results regarding the response rates observed, mainly related to the dose and schedule of administration used. To obtain additional data concerning the efficacy and toxicity of paclitaxel in intermediate and high grade NHL we initiated a phase II study using a 3-hour infusion of high doses of paclitaxel.
Design and methods: The eligibility criteria included patients with relapsed or refractory aggressive NHL, a performance status < or = 2 (WHO index), a platelet count > or = 100,000/microL, a neutrophil count > or = 2,000/microL, measurable disease, and adequate hepatic function. Patients were excluded if they were infected with HIV, had a left ventricular ejection fraction < 50%, or prior peripheral neuropathy. Paclitaxel was administered as a 3-hour infusion at a dose of 250 mg/m2 every 3 weeks for a maximum of 6 courses.
Results: Of 45 eligible patients, 42 received a total 73 courses of paclitaxel. Forty patients were assessable for response (89%), and 42 for toxicity (93%). Six patients (15%) achieved a partial (n = 4) or a complete remission (n = 2). Responses were observed in intermediate grade (n = 4) as well as in high grade lymphoma (n = 2). The main factor influencing the response to paclitaxel was the median duration of response to previous chemotherapy regimens which was 3 times longer in patients who responded to paclitaxel (16.3 months) than in patients who did not respond to paclitaxel (5.2 months) (p<0.05). The most common serious side effects were related to the hematologic toxicity of paclitaxel, and included grade IV granulocytopenia in 20 cases (48%), grade III/IV thrombocytopenia in 14 cases (33%) and grade III-IV anemia in 13 cases (31%).
Interpretation and conclusions: Despite frequent manageable hematologic toxicity, paclitaxel is usually well tolerated at a dose of 250 mg/m2 given by a 3-hour infusion. However, the clinical efficiency as a single therapy seems modest in relapsed or refractory aggressive lymphoma.