Ex vivo expanded unselected peripheral blood: progenitor cells reduce posttransplantation neutropenia, thrombocytopenia, and anemia in patients with breast cancer.

The safety and efficacy of administering ex vivo expanded peripheral blood progenitor cells (PBPC) to patients with breast cancer who undergo high-dose chemotherapy and PBPC transplantation was investigated. Unselected PBPC were cultured in gas-permeable bags containing 1-L serum-free media, granulocyte colony-stimulating factor, stem cell factor, and pegylated megakaryocyte growth and development factor for 9 days. Cell dose cohorts were assigned to have between 2 and 24 x 10(9) PBPC cultured at 1, 2, or 3 x 10(6) cells/mL. Twenty-four patients received high-dose chemotherapy followed by infusion of the cultured PBPC and at least 5 x 10(6) CD34(+) uncultured cryopreserved PBPC per kilogram. No toxicities resulted from infusions of the ex vivo expanded PBPC. The study patients had shorter times to neutrophil (P =.0001) and platelet (P =.01) recovery and fewer red cell transfusions (P =.02) than 48 historical controls who received the same conditioning regimen and posttransplantation care and at least 5 x 10(6) CD34(+) PBPC per kilogram. Improvements in all these endpoints were significantly correlated with the expanded cell dose. Nine of 24 (38%) patients recovered neutrophil counts above 500/microL by day 5 or 6 after transplantation, whereas none of the controls had neutrophil recovery before the eighth day. Seven (29%) patients had neutropenia for 3 or fewer days, and 9 (38%) patients did not experience neutropenic fevers or require broad-spectrum antibiotics. Therefore, ex vivo expanded PBPC are capable of ameliorating posttransplantation neutropenia, thrombocytopenia, and anemia in patients receiving high-dose chemotherapy.