This study was performed to determine the clinical activity and safety of paclitaxel in the treatment of patients with refractory or relapsing aggressive Non-Hodgkin's lymphoma (NHL). Between May 3, 1994 and February 16, 1996, 39 patients with refractory or relapsing NHL consented to be enrolled in two, multicenter, open-labelled studies to evaluate the efficacy, safety, time to progression and overall survival of paclitaxel given at a dose of 175 mg/m2 by a 3-hour IV infusion every three weeks without G-CSF use. Data from the two studies is combined. One patient, although registered, did not receive treatment. Of the remaining 38 patients, 17 men and 21 women aged 26-82 years (median 60) were given 104 courses of paclitaxel [median 2 (range 1-6)]. Seventeen patients had stage IV, 7 stage III, 8 stage II, 5 stage 1 and 1 unknown stage of disease. Histologic grades included 1 low, 33 intermediate, and 4 high. Three patients had bone marrow involvement. Median time from diagnosis to study entry was 19 months (1-160). The median number of previous chemotherapy regimens was 2 (range 1-6). Three of the 35 (8.6%) patients evaluable for response had partial remission (PR) of their disease for 1-7 months (median 2) and 11/35 (31.4%) stable disease (SD) for 1 to 19 months (median 3). All three responders and 3 of the 11 SD patients had received paclitaxel after relapsing from a CR. At analysis, nine of the 38 patients were alive. Median duration of follow up at analysis was 6 months (3 days-29 months). The estimated survival rates for all patients at 1 and 2 years are 34% and 27%, respectively (Kaplan-Meier) from the start of paclitaxel treatment. The median survival time was 5.4 months (3 days to 28+ months). Febrile neutropenia occurred in two patients. Seven (18%) patients developed a neutrophil nadir of < 0.5 x 10(9)/L and 2 (5%) patients developed a platelet nadir of < 50 x 10(9)/L. Six patients received blood transfusions. Non-hematologic toxicity was generally mild to moderate with all patients experiencing some toxicity. Twenty-seven patients experienced grade III toxicity including: alopecia (n = 19), pain (n = 9), fatigue (n = 5), nausea/vomiting (n = 3), diarrhoea (n = 2), pulmonary/shortness of breath (n = 2), anorexia (n = 1) and fluctuating levels of consciousness and somnolence (n = 1). Two patients experienced grade IV toxicity (infection, peripheral neuropathy, pain). No patient discontinued paclitaxel for a severe hypersensitivity reaction. In summary, administered as a 3-hour infusion, paclitaxel 175 mg/m2 results in mild myelotoxicity but minimal antitumor activity in patients with refractory NHL.