CELLPRO BEGINS PHASE III TRIAL IN MULTIPLE MYELOMA; New Trial Designed to Demonstrate Tumor-Cell Depletion.

SEATTLE--(BUSINESS WIRE)--Jan. 16, 1995--CellPro Inc. (NASDAQ:CPRO) announced today that it had begun a Phase III clinical trial to demonstrate that using its CEPRATE SC Stem Cell Concentration System to positively select CD34 antigen-expressing cells from the peripheral blood of patients also results in a significant depletion of tumor cells from the resulting transplant. The trial is being conducted in advanced multiple myeloma patients undergoing peripheral blood stem cell (PBSC) transplantation to restore their marrow with hematopoietic (blood-forming) stem cells following myeloablative (marrow-killing) chemotherapy.

The pivotal Phase III trial is a multicenter, randomized study expected to enroll 134 patients. The trial will be conducted at fifteen major cancer treatment centers across the United States and Canada. Sites in the US will include cancer centers in Arizona, California (5), Florida, Illinois, Missouri, Massachusetts, Nebraska, Pennsylvania, and Texas (2). The site in Canada is in Toronto.

There are two primary objectives for the trial. The efficacy objective is to demonstrate the effectiveness of the CEPRATE SC System in depleting tumor cells from autologous peripheral blood purified for CD34 antigen-expressing stem cells. The CD34 antigen is a surface marker for the hematopoietic stem and early progenitor cells that are essential for post-transplant engraftment. The antigen apparently is not expressed on malignant plasma cells or their potential precursors. The safety objective of the trial is to demonstrate equivalent marrow engraftment in patients receiving CEPRATE-purified PBSCs compared with patients receiving unpurified PBSCs.

"High-dose chemotherapy has been shown to be very effective in treating multiple myeloma, but such therapy is limited due to the debilitating effects of these cytotoxic drugs on the blood and immune systems," said Ronald J. Berenson, MD, chief medical and science officer for CellPro. "In addition, recent marking studies in several different malignancies have demonstrated that transplanted tumor cells can contribute to patient relapse." Added Dr. Berenson, "The aim of the trial is to repopulate the hematopoietic systems of patients following intensive chemotherapy with tumor cell-reduced PBSC. We believe that Phase II testing has supported the feasibility of this treatment approach, and we look forward to generating larger-scale data in this Phase III trial."

An earlier multicenter, Phase II trial demonstrated that of 32 evaluable advanced multiple myeloma patients who received CEPRATE SC-purified PBSC transplants, 31 achieved complete or partial remission, and one achieved a minimal response. Since the trial, two patients have relapsed and the remainder continue to show an ongoing reduction in paraprotein (disease-marker) levels. The median time to follow-up is nine months.

Multiple myeloma is a lethal malignancy of the marrow that is not considered curable with standard therapy. It accounts for approximately 10,000 deaths annually in the United States and has a median survival following diagnosis of 36 to 40 months. CellPro and its clinical collaborators have been exploring peripheral blood progenitor cell transplantation as an approach to improve the efficacy of autologous transplantation in patients with multiple myeloma. A major concern in transplanting a multiple myeloma patient's own cells to restore the blood and immune systems has been the reinfusion of malignant plasma cells responsible for the disease, since a high population of myeloma cells is located in the patient's bone marrow. Malignant cells have been found in peripheral blood, but at lower levels.

The CEPRATE SC Stem Cell System is designed to isolate and purify stem cells from patients' peripheral blood or bone marrow. The system uses a patented avidin-biotin binding system to obtain sufficient quantities of stem cells for use in reconstituting hematopoietic cells following cancer chemotherapy and in other stem cell-related therapies affecting the blood and immune systems. Additionally, the CEPRATE SC System is invaluable as a cell-separation tool for research in gene therapy. The CEPRATE SC was first commercially available in Europe, where it is being used currently by approximately 90 bone marrow transplant teams in 86 hospitals in 14 countries. It is currently being tested in over 60 clinical trials in the US, Canada, Europe and Australia for various applications including gene therapy. Over 1,000 patients have been treated in protocols using the CEPRATE SC. Approval to sell the CEPRATE SC in Canada was recently granted by the Canadian government. A pre-marketing approval application for use of the CEPRATE SC for hematopoietic support in cancer-related therapies was submitted to the US Food and Drug Administration (FDA) in December 1993. In December 1994, the FDA advised the Company that the application would require amendment to provide additional data before it could be approved.

Located in Bothell, Wash., CellPro is a biotechnology company specializing in the development, manufacturing and marketing of proprietary continuous-flow, cell-selection systems for use in a variety of therapeutic, diagnostic and research applications.

CONTACT: CellPro Inc.

Lee M. Parker, 206/485-7644