Outcomes of G-CSF alone vs G-CSF with upfront plerixafor vs G-CSF/chemotherapy for collection of autologous stem cells in patients with multiple myeloma.

Abstract

e19504 Background: Strategies for optimizing the collection of peripheral blood stem cells (PBSC) for autologous stem cell transplant (ASCT) in patients with multiple myeloma (MM) vary among transplant centers, and include the use of G-CSF alone or in combination with plerixafor, or mobilization chemotherapy + G-CSF. In 2010, we started using “upfront” plerixafor, given on the day before the PBSC collection. Methods:We retrospectively analyzed the outcomes of 423 consecutive MM patients who underwent PBSC collections at the Penn State Hershey Cancer Institute. PBSC were collected after mobilization chemotherapy + G-CSF 5 mcg/Kg/day (group A, 91 pts), G-CSF alone, 10-16 mcg/Kg/day (group B, 72 pts), and G-CSF with “upfront” plerixafor 0.16-0.24 mg/Kg on the day before the stem cell collection (group C, 245 pts). Fifteen patients were excluded from the analysis because they collected with chemotherapy + plerixafor, received pegylated G-CSF, or plerixafor “on demand”, i.e., after failure to achieve an adequate number of stem cells on the first day of collection. We compared yields, number of days required for apheresis, clinical outcomes, and adverse events among these groups. Results: The median number of PBSC collected was 16.4 (range, 0.1-134), 4.2 (range, 0-12), and 6.2 (range, 0.2-41.2) million CD34+ cells/Kg in group A, B, and C, respectively (p<0.001). The mean number of days to collect PBSC was 1.5, 1.5, and 1.3 in group A, B, and C, respectively (p=0.033). Collection failure, defined as a yield <2 million CD34+cells/Kg, was observed in 5 (5.5%), 9 (12.5%), and 15 (6.1%) patients of group A, B, and C, respectively (p<0.001). Twenty patients in group A developed neutropenic fever requiring hospital admission, and 1 of them died of septic shock, whereas no mortality was observed in groups B or C. No difference in the rapidity of PBSC engraftment, progression-free survival, and overall survival was observed among the 3 groups. Conclusions:In patients with MM, the upfront use of plerixafor with G-CSF provided the best collection strategy: it avoided the morbidity and mortality associated with the mobilization chemotherapy, and it provided higher yields than G-CSF alone.