Transplantation with low-density autologous PBSC prepared with BDS60 for women with Stage II, III and IV breast cancer

BDS60 is a novel buoyant density solution, whose density has been adjusted to enrich PBSC from subjects who have been mobilized with cytokines alone, or cytokines plus chemotherapy. This report describes the use of BDS60 to enrich autologous PBSC that were used for hematological reconstitution after myeloablative chemotherapy in women with breast cancer. Fifty-one consecutive patients with high-risk Stage II or III breast cancer or chemotherapy-sensitive Stage IV breast cancer were enrolled. Forty-seven completed treatment and were evaluable. After mobilization with cyclophosphamide (4.0g/m2 i.v. once) and filgrastim (10μg/kg/day), the patients underwent leukapheresis and the products were enriched with BDS60 using the DACS300 Kit. Myeloablative chemotherapy, given on Day −25 through Day −22, consisted of cyclophosphamide (1.5 g/m2/day), thiotepa (150mg/m2/day) and carboplatin (200mg/m2/day). Forty-one patients underwent a single leukapheresis procedure to achieve the target number of BDS60-enriched CD34+ cells for transplantation (≥ 2×106/kg). Five of the other six patients had less than the target number of cells in the leukapheresis product and thus required 2–4 leukapheresis procedures. Median cell recovery was 76.8% for CD34+ cells, 39.1% for nucleated cells, and 17.7% for platelets. Erythrocyte contamination of the final product was negligible. The median time to sustained neutrophil count > 500/mm3 was 9 days (range: 8–12) and the median time to platelet count > 20 000/mm3, without transfusion support, was also 9 days (range: 6–15). There were no late graft failures. Infusion-related adverse events were mild and no adverse events were attributed to the use of BDS60 to enrich CD34+ cells. BDS60 is an effective, rapid method for enrichment of CD34+ cells by buoyant density centrifugation and the resulting cell product is safe and effective for engraftment after myeloablative therapy.