Plasma Concentrations and AUC of Pegfilgrastim Have No Impact on Its Efficacy in Peripheral Blood Progenitor Cell Mobilization.

The use of pegfilgrastim (Neulasta™, Amgen Inc., Thousand Oaks, USA) in mobilization of CD34+ peripheral blood progenitor cells (PBPC) is promising because a continuously increased G-CSF level is suspected to exert a higher biological activity than pulsatile elevations after intermittent injections of unconjugated G-CSF. In clinical phase I/II trials we evaluated the agent both in combination with chemotherapy to mobilize autologous PBPC in 40 cancer patients and as growth factor treatment alone in a small pilot study with 25 allogeneic stem cell donors. The results were reported recently (Kroschinsky et al., Blood 2004; 104: 2922abstr.).