Highly purified CD34+ cells isolated using magnetically activated cell selection provide rapid engraftment following high-dose chemotherapy in breast cancer patients

The primary objective of this study was to evaluate the safety of infusion of CD34(+) cells, selected using a clinical scale magnetically activated cell sorting device, assessed by time to hematological engraftment and incidence of adverse events, Secondary objectives included evaluation of device performance in terms of purity and recovery of the CD34(+) cell product. Breast cancer patients suitable for transplantation received cyclophosphamide and filgrastim for mobilisation, followed by three leukaphereses, The products of the first two leukaphereses underwent CD34(+) cell selection, The product of the third leukapheresis was cryopreserved unmanipulated. Following high-dose cyclophosphamide, thiotepa and carboplatin, selected CD34(+) cells were infused. In 54 patients who received selected cells only, the median time to platelet recovery and neutrophil recovery was 11 days (range 5-51) and 9 days (range 5-51), respectively. There were no adverse events associated with infusion of selected cells. A total of 126 leukapheresis samples was available before and,after selection for central CD34(+) analysis. The median purity was 96.1% (27.4-99.4) and the median recovery was 52.3% (15.2-146.3). These data show that cells selected using magnetically activated cell selection provide safe and rapid engraftment after high-dose therapy.