PHASE-I STUDY OF IN-VIVO LENOGRASTIM (RHUG-CSF) FOR STEM-CELL COLLECTION DEMONSTRATES IMPROVED NEUTROPHIL RECOVERY AFTER AUTOLOGOUS BONE-MARROW TRANSPLANTATION

Colony stimulating factors and especially rHuG-GSF, the first availabl e neutrophil growth factor, have led to considerable interest in the f ield of stem cell transplantation because of their ability to induce s tem cell peripheralization either alone or in association with high-do se chemotherapy. Few data exist, however, on the impact of rHuG-CSF on large scale bone marrow collection and autologous bone marrow transpl antation (ABMT). This phase I, non-randomized, dose escalation study o f rHu-G-CSF (lenograstim) administered to 30 patients at doses ranging from 1 to 40 mu g/kg/day for 5 days before bone marrow harvesting sho wed that priming with rHu-G-CSF in vivo increased the number of bone m arrow cells and D14 myeloid restricted progenitors (CFU-GM) and led to a better neutrophil recovery after ABMT compared with a contemporary unprimed control population. Otherwise, this study established that 5 days of rHuG-CSF therapy, as a sole stimulus, induced a tenfold increa se in the circulating CFU-GM amongst which immature progenitors, estim ated by the Delta assay (secondary CFU-GM grown after 7 days of liquid culture/primary CFU-GM), are detected. These conclusions were valid f or doses as low as 2 mu g/kg/day which induced only mild neutrophilia up to the highest dose (40 mu g/kg/day) and suggest that a short cours e of rHuG-CSF is beneficial in increasing the stem cell collection.