Fixed-dose single administration of pegfilgrastim vs daily filgrastim in patients with breast cancer and lymphoma undergoing autologous peripheral blood stem cell transplantation

Abstract

16534 Background: Pegylated filgrastim is a new formulation of a granulocyte colony-stimulating factor that has a long circulating half-life, permitting a single dose of filgrastim per cycle of chemotherapy. Methods: To evaluate whether a single subcutaneous injection of pegfilgrastim (6 mg) is as safe and effective as daily filgrastim (5 mcg/kg/day), 40 consecutive autologous stem cell transplantations performed for breast cancer and lymphomas have been analysed. Median age was 47 yrs (20–61) and 48 yrs (30–63) in pegfilgrastim and filgrastim group, respectively. All patients had normal bone marrow biopsy. The first cohort of patients received 5 mcg/kg/day of filgrastim starting from day 5 post transplantation and the second cohort of patients received a single subcutaneous injection of 6 mg pegfilgrastim on day 5 after transplantation. Results: Median duration of grade 4 neutropenia in the pegfilgrastim and filgrastim groups was 7 (4–9) and 6 (5–9) days, respectively (P 0.29). Neutropenic fever incidence was significantly higher in filgrastim group, 9/20 vs 16/20 (P 0.048), the median duration was not significantly different, 1 (1–6) vs 3 (1–7) days. The grade 3–4 mucositis was higher in filgrastim patient group, 4/20 vs 13/20 in pegfilgrastim and filgrastim, respectively (P 0.009). The adverse events observed during post-transplant aplasia were attributable to complications arising from myelo-suppressive chemotherapy or the primary disease. The only occurring adverse event considered to be cytokine related was mild to moderate bone pain. The overall incidence of bone pain requiring non-narcotic analgesia was not statistically different, 20% (4/20) in pegfilgrastim patients and 40% (8/20) in filgrastim patients. The patients in filgrastim group received a mean of 9.8 daily injections. Conclusions: A single injection of pegfilgrastim administered at day 5 post transplant shows comparable safety and efficacy profiles to daily injections of filgrastim and may be cost-effective. No significant financial relationships to disclose.