BOTHELL, Washington--CellPro, Incorporated has received FDA approval for label expansion of the companys Ceprate SC Stem Cell Concentration System to include the processing of peripheral blood progenitor cells (PBPCs) to obtain a CD34+ cell enriched population for use as hematopoietic support after myeloablative chemotherapy in patients with CD34-negative tumors.
Studies have shown that these cells contain a reduced number of tumor cells in the autograft, compared with unse-lected PBPCs, but have not determined whether use of selected PBPCs will result in an improved progression-free or overall survival. Ceprate was originally approved in 1996 to select progenitor cells from bone marrow for transplantation after myeloablative chemotherapy.
The FDAs decision was based on data presented to the Biological Response Modifiers Committee by CellPro (see ONI, May, 1998). The data came from a multicenter, randomized phase III clinical trial involving 134 multiple myeloma patients receiving high-dose chemotherapy followed by stem cell transplantation. The results showed a median 1,000-fold reduction of tumor cells with cell selection and purging, with equivalent neutrophil engraftment.
CellPros president and CEO, Richard Murdock, said that the company "is especially pleased that the expanded label is very broad in its applicability . . . and is not limited to purging multiple myeloma tumor cells." The Ceprate system has been shown in other studies to reduce the number of tumor cells in PBPC autographs of patients with breast cancer and non-Hodgkins lymphoma.
The Ceprate system concentrates CD34+ cells using a proprietary continuous-flow immunoadsorption technique. After cell harvest and preparation, the cells are incubated with biotinylated murine anti-CD34 monoclonal antibodies that bind selectively to CD34+ cells. As they flow through a column, the antibody-labeled CD34+ cells bind to avidin-coated beads while unlabeled cells are washed out.