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

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.

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).

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.

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