Purpose: The aim of this prospective randomized trial was to examine the efficacy and safety of filgrastim after high-dose chemotherapy and autologous bone marrow transplantation (ABMT) Patients and Methods: Patients with poor-risk non-Hodgkin's lymphoma or relapsed Hodgkin's disease were treated in a randomized, open-label trial to study the use of filgrastim as on adjunct to high-dose chemotherapy and ABMT. Of 43 assessable patients, 19 were randomized to receive filgrastim by continuous subcutaneous infusion at a dose of 10 mu g/kg/d, 10 to filgrastim 20 mu g/kg/d, and 14 to a parallel control group that received no filgrastim after ABMT. Results: For all filgrastim-treated patients analyzed together, the median time to neutrophil recovery greater than or equal to 0.5 x 10(9)/L after the day of ABMT was significantly accelerated to 10 days compared with 18 days in control patients (P = .0001). The median number of platelet transfusions was identical in both groups. Clinical parameters, including the median number of days with fever (1 v 4, P = .0418) and neutropenic fever (5 v 13.5, P = .0001) were significantly shorter in the filgrastim than in the control group. The number of days on intravenous antibiotics and duration of hospitalization were also shorter in the treated groups; however, the differences did not reach statistical significance. For patients treated with the two different dose levels of filgrastim, the neutrophil recovery and clinical results were similar. Filgrastim-associated toxicity appeared to be minimal, with five adverse events considered at least possibly related to filgrastim: two in the higher-dose group and three in the lower-dose group. All of these were rated moderate, except one case of severe bone pain that did not preclude continued filgrastim treatment at a lower dose. Survival and relapse-free survival were similar for control and filgrastim-treated patients. Conclusion: Taken together, the results of this first randomized study support the role of filgrastim given as an adjunct to ABMT in accelerating neutrophil recovery, as well as in reducing treatment-related morbidity and overall duration of the treatment procedure. (C) 1994 by American Society of Clinical Oncology.