MOBILIZATION OF CIRCULATING PROGENITOR CELLS IN MULTIPLE-MYELOMA DURING VCAD THERAPY WITH OR WITHOUT RHG-CSF

Background. Circulating progenitor cells (CPC), when infused in large numbers, rapidly repopulate the marrow after myeloablation with high-d ose therapy. In multiple myeloma (MM), as in other disorders, differen t chemotherapy regimens, including single-as well as multiple-agent ch emotherapy, with or without hemopoietic growth factors, have been prop osed to mobilize these progenitor cells into the blood. Here we report our experience with a drug combination called VCAD and compare the re sults to those obtained by adding rhG-CSF to the same combination. Met hods. Fourteen MM patients were given one course of VCAD, a chemothera py association of vincristine 2 mg, cyclophosphamide 4x0.5 g/m(2), adr iamycin 2x50 mg/m(2) and dexamethasone 4x40 mg, before undergoing aphe resis to collect CPC for autografting. Seven also received rhG-CSF (fi lgrastim) 5 mcg/kg/day over the period of apheresis. These latter were allocated to rhG-CSF treatment sequentially from the time the drug be came available for clinical use. Results. Following VCAD-induced pancy topenia, CFU-GM peaked at a median of 853/mL (range 96-4352; 7.6 times basal level). RhG-CSF administration increased CFU-GM levels but not significantly. With rhG-CSF the CFU-GM peak was reached sooner, toxici ty was reduced and granulocytopenia less protracted. Fewer aphereses w ere run in the rhG-CSF group, there were higher yields per single run, and patients began and completed their collection program more quickl y. Conclusions. The VCAD association is able to mobilize CPC in patien ts with MM, and rhG-CSF is recommended as a fundamental part of the pr iming schedule.