Purpose: To assess the clinical and economic benefit of low-dose (50 microg/m2) filgrastim after peripheral blood stem-cell transplantation (PBSCT) in a randomized, placebo-controlled double-blinded study.
Patients and methods: Thirty-eight patients with lymphoproliferative disorders were randomized to receive low-dose filgrastim (19 patients) or placebo (19 patients) beginning on the first day after stem-cell reinfusion and continuing until absolute neutrophil count (ANC) was greater than 0.5 x 10(9)/L. All patients received greater than 2.5 x 10(6) CD34+ cells/kg, which was mobilized with chemotherapy and filgrastim 300 microg from the fifth day. An economic analysis was performed based on the outcome in the two groups.
Results: Neutrophil engraftment was significantly more rapid in patients who received filgrastim with a median number of days until ANC was greater that 0.5 x 10(9)/L of 10 (9 to 13) versus 14 (9 to 19; P < .0001). The time to reach an ANC greater than 1 x 109/L was 12 (9 to 14) versus 16 days (10 to 25; P < .0001). The total number of patients who required intravenous antibiotic therapy was lower in the filgrastim-treated group (68%) compared with the placebo group (89%); also, the median number of days with fever and the duration of antibiotic therapy were shorter, although these differences did not reach statistical significance. However, although only three of 19 (16%) patients who received filgrastim required amphotericin, 11 of 19 (58%) who received placebo did require it, and amphotericin usage was significantly less in the filgrastim group (P = .029). Finally, in-patient stay was significantly shortened in those who received filgrastim from 16 (13 to 23) to 13 days (11 to 18; P = .0003).
Conclusion: Low-dose filgrastim significantly reduces neutrophil engraftment time post-PBSCT and also reduces in-patient stay and costs, which makes it economically viable for patients who are undergoing high-dose chemotherapy.