Mobilization of hematopoietic progenitor cells with standard or reduced dose filgrastim after vinorelbine in multiple myeloma patients. a randomized prospective single center phase II study

Abstract Vinorelbine combined with filgrastim at a dose of 10 µg/kg of body weight (BW) per day is a reliable and well-tolerated regimen for mobilization of hematopoietic progenitor cells (HPCs) in patients with multiple myeloma. This prospective, randomized, phase II study was initiated to assess the feasibility of a reduced filgrastim dosage. Vinorelbine was combined with either standard-dose filgrastim (10 µg/kg BW per day) or reduced-dose filgrastim (5 µg/kg BW per day). Leukapheresis sessions were planned to start at day 8 and were continued until the predefined target amount of 4 × 10 6 HPCs/kg BW was collected. The study demonstrated the feasibility of vinorelbine combined with reduced daily filgrastim with a mean of 1.29 leukapheresis sessions necessary per patient (95% confidence interval, .95 to 1.7). All patients could start leukapheresis as planned at day 8, and the collection success rate was 100% for the whole patient collective after a maximum of 2 leukapheresis sessions. No statistically significant differences with regard to the amount of HPCs collected between the 2 groups were observed ( P  = .99). Accordingly, no differences were seen with regard to length of hospitalization for autotransplant ( P  = .34) and duration of neutrophil ( P  = .93) and platelet engraftment ( P  = .42). Patients receiving reduced-dose filgrastim reported significantly lower peak pain values in a numeric analogue scale ( P  = .01), and the costs were significantly lower than in patients undergoing standard-dose chemomobilization ( P  = .001). Vinorelbine 35 mg/m 2 plus filgrastim 5 µg/kg BW once per day until completion of HPC collection is feasible and appears to be advantageous with respect to the severity of pain intensity and treatment costs.