Abstract
Vinorelbine combined with filgrastim (r-metHuG-CSF) 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 (HPC) in patients with multiple myeloma. This prospective randomized phase 2 study was initiated to assess the feasibility of a reduced filgrastim dosage. Vinorelbine was combined with either standard dosed filgrastim (10 µg/kg body weight (BW) per day) or reduced dosed 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 x 106 HPC/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 0.95-1.7). 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 two leukapheresis sessions. No statistically significant differences with regard to the amount of HPC collected between the two groups were observed (p=0.99). Accordingly, no differences were seen with regard to length of hospitalization for autotransplant (p=0.34), duration of neutrophil (p=0.93) and platelet engraftment (p=0.42). Patients receiving reduced dose filgrastim reported significantly lower peak pain values in a numerical analogue scale (p=0.01), and the costs were significantly lower than in the patients undergoing standard dosed chemo-mobilization (p=0.001). Vinorelbine 35 mg/m2 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.