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

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.