Randomized study of filgrastim versus molgramostim after peripheral stem cell transplant in breast cancer

Abstract

Background and objective: The aim of this study was to compare the efficacy and toxicity of Filgrastrim (granulocyte colony-stimulating factor-G-CSF) versus molgramostim (granulomonocyte colony-stimulating factor-GM-CSF) after autologous peripheral blood stem cell transplant (PBSCT) in patients with breast cancer. To the best of our knowledge no randomized studies comparing filgrastrim and molgramostim have been published.

Design and methods: Forty-two patients with breast cancer were randomized to receive filgrastrim versus molgramostim subcutaneous at a dose of 5 mcgr/kg starting on day 6 after PBSCT. PBSC were collected in all patients after stimulation with filgrastrim and infused following conditioning with cyclophosphamide, cisplatin and carmustine (n = 25) or cyclophosphamide, carboplatin and thiotepa (n = 17).

Results: The median days to reach > 0.5 x 10(9)/L granulocytes was similar for patients receiving filgrastrim (10.5 +/- 0.8 days) and molgramostim (10.2 +/- 0.9 days). No significant differences were observed in time taken to reach 20 x 10(9)/L platelets 10.8 +/- 2.2 vs 12 +/- 2.9 for filgrastrim and molgramostim, respectively, but in time to reach 50 x 10(9)/L was slightly lower in the filgrastrim arm (15.1 +/- 2.9 vs 18.9 +/- 8.4, p = 0.03). Nevertheless there were no differences in the number of platelets transfused. Time of discharge was two days earlier in the filgrastrim arm (15 +/- 4.2 vs 17.4 +/- 4.7, p = 0.04). Finally, the incidence of adverse side effects attributable to the cytokines (filgrastrim or molgramostim) was equivalent and only present in 19% of the patients.

Interpretation and conclusions: This randomized study shows that filgrastrim and molgramostim yield quite similar toxicity and efficacy for early hematopoietic reconstitution after PBSCT in breast cancer patients.