Ancestim (recombinant human stem cell factor, SCF) in association with filgrastim does not enhance chemotherapy and/or growth factor-induced peripheral blood progenitor cell (PBPC) mobilization in patients with a prior insufficient PBPC collection.

Summary:Up to a third of autologous transplantation candidates fail to mobilize hematopoietic progenitors into the peripheral blood with chemotherapy and/or growth factor treatment, thus requiring innovative mobilization strategies. In total, 20 cancer patients unable to provide adequate PBPC products after a previous mobilization attempt were treated with ancestim (20?µg/kg/day s.c.) and filgrastim (10?µg/kg/day s.c.). In 16 patients, the pre-study mobilization was with filgrastim alone. Eight patients underwent single large volume leukapheresis (LVL) and 12 multiple standard volume leukaphereses (SVL) in both mobilizations. Pairwise comparison of peripheral blood CD34⁺ cell concentrations on the day of first leukapheresis failed to document synergism-median CD34⁺/µl of 3.2 (<0.1 to 15.4) and 4.5 (1-28.56) for the pre-study and on-study mobilizations (P=0.79, sign test), and 4.2 (<0.1-15.4) and 5 (1-28.56), respectively, for the 16 patients previously mobilized with filgrastim alone (P=1, sign test). The number of CD34⁺ cells/kg collected per unit of blood volume (BV) processed was similar in both mobilizations-median 0.1×10⁶/kg/BV and 0.09×10⁶/kg/BV, respectively (P=1, sign test). In this phase II study, the combination of ancestim and filgrastim did not allow adequate PBPC mobilization and collection in patients with a previous suboptimal PBPC collection.Bone Marrow Transplantation (2004) 34, 683-691. doi:10.1038/sj.bmt.1704602 Published online 23 August 2004 [ABSTRACT FROM AUTHOR]