Purpose: To assess the safety, tolerability, and hematopoietic efficacy of sequential and concomitant administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and recombinant human interleukin-3 (rhIL-3), to accelerate reconstitution of hematopoiesis following myeloablative chemotherapy and autologous bone marrow transplantation (ABMT) for heavily pretreated lymphoma patients.
Patients and methods: Fifty-four consecutive patients with refractory or relapsed non-Hodgkin's lymphoma (NHL; n = 30) and Hodgkin's disease (HD; n = 24) were studied. Two different conditioning regimens were used for ABMT: carmustine, cyclophosphamide, etoposide, and cytarabine (BAVC) and carmustine, melphalan, etoposide, and cytarabine (BEAM) for NHL and HD, respectively. Patients were enrolled sequentially onto one of three treatment groups: group 1, G-CSF (5 micrograms/kg/d subcutaneously [SC]) from day +1 after reinfusion of autologous marrow (n = 23); group 2, G-CSF from day +1 combined with IL-3 (10 micrograms/kg/d SC) from day +6 (n = 22, overlapping schedule); and group 3, G-CSF treatment discontinued at day +6 before initiation of IL-3 administration (n = 9, sequential schedule). In the three groups, growth factor(s) was administered until the granulocyte count was greater than 0.5 x 10(9)/L for 3 consecutive days.
Results: The study cytokines were generally well tolerated. No side effects were observed when G-CSF was given alone. Four of 31 patients (12.9%) who received SC IL-3 had one severe adverse event defined as World Health Organization (WHO) grade 3 to 4 toxicity (fever, n = 2; pulmonary toxicity, n = 2) and were withdrawn from the study. Groups 2 and 3 did not differ as for treatment tolerability, whereas we observed a trend toward a faster hematopoietic recovery when IL-3 was administered concomitant with G-CSF from day 6 (ie, group 2). Pooled together, patients who received IL-3 showed a median time to achieve a granulocyte count greater than 0.1 and greater than 0.5 x 10(9)/L of 8 and 11 days, respectively. The median time to an unsupported platelet count greater than 20 and 50 x 10(9)/L was 15 and 20 days, respectively, and only one patient did not reach a normal platelet count. The median number of days to hospital discharge was 16 after ABMT (range, 12 to 29). When the hematologic reconstitution of patients in groups 2 and 3 was compared with that of patients in group 1, the addition of IL-3 resulted in a significant improvement of multilineage hematopoietic recovery, lower transfusion requirements, a lower number of documented infections, and shorter hospitalizations.
Conclusion: We conclude that the combination of G-CSF and IL-3 is safe and well tolerated in intensively pretreated lymphoma patients, undergoing ABMT and results in rapid hematopoietic recovery following myeloablative chemotherapy.