Successful Engraftment of Autologous CD34+ Stem Cells after High-Dose Therapy and Fixed Dose (6 mg) Pegfilgrastim.

High-dose (HD) therapy plus Autologous Stem Cell Transplantation (ASCT) is a milestone treatment program for most hematologic malignancies. Daily subcutaneous injections of G-CSF (filgrastim/lenograstim) until ANC > 500/μl are routinely administered following ASCT, in order to accelerate hematopoietic recovery and reduce neutropenic complications. Pegfilgrastim has been shown to have similar efficacy when compared to G-CSF for chemotherapy-induced neutropenia, but little is known about its use in the ASCT setting. We used a 6 mg fixed dose of Pegfilgrastim on day +4 following ASCT in 46 patients (22 M/24 F; median age 56 yrs; r 22-70 yrs) with multiple myeloma (25 pts) and relapsed or refractory Hodgkin’s and non-Hodgkin’s lymphoma (21 pts). Patients received peripheral CD34+ stem cells (median number 4.4 x 10⁶/Kg; r 1.8 – 11.8) harvested after mobilizing chemotherapy (cytoxan, vinorelbine/cytoxan, R-IEV, IGEV, R-ICE) and G-CSF. Standard conditioning regimens (HD-Melphalan or BEAM) were used. Engraftment results were compared to those from a historical control group of 182 patients (median age 56 yrs; r 16-74 yrs) who had received HD-Melphalan or BEAM and ASCT (median CD34+ cells 7.6 x 10⁶/Kg, r 1.8–4.6) supported by G-CSF (5 μg/kg/day from day +5 until ANC>500/μl). Median number of days to ANC>500/μl were comparable between the Pegfilgrastim (10, r 8-15) and G-CSF (11, r 7–22) groups, as well as the median number of days to PLT>20,000/μl (Pegfilgrastim = 12, r 9–20 vs G-CSF= 12, r 7–29). Overall infectious rates, including FUO and documented infections, were of 48% and 39% for Pegfilgrastim and G-CSF groups, respectively (p=NS). Median number of days on i.v. antibiotics were 0 (r 0–18) and 6 (r 0–13) for the Pegfilgrastim and G-CSF groups, respectively. No significant differences in the incidence of bone pain, intensity of transfusion support and length of hospital stay were documented between the two groups. These data indicate that a fixed (6 mg) single-dose of Pegfilgrastim is safe and effective to accelerate engraftment after ASCT. No significant differences with G-CSF were apparent as to engraftment times and overall infectious complications. Growth factor costs were however in favor of Pegfilgrastim (Euro 690 vs 892 for a median of 10.5 G-CSF doses).