CellPro Inc. has received marketing approval from the FDA for itsCeprate SC Stem Cell Concentration System, a device indicated forpurification of stem cells for bone marrow transplantation.

The Ceprate SC System is the first cell processing system to beapproved by the FDA for this indication.

"We received approval on Friday," Joann Reiter, director of investorrelations at CellPro, told BioWorld Today, "and the product went onthe market a half-hour later."

The product, she said has been on sale in Europe where sales haveincreased 40 to 50 percent per year on a quarter-to-quarter basis.

The Ceprate SC Stem Cell System was developed by CellPro, ofBothell, Wash., and will be priced in the U.S. at $4,325 for thedisposable kits, Reiter said.

The Ceprate SC Stem Cell Concentration System is used to harveststem cells from bone marrow prior to chemotherapy, radiation or atransplant. The separated cells are returned to the patient afterchemotherapy or other marrow-destroying procedures to help restorebone marrow.

CellPro's avidin-biotin immunoaffinity cell-selection system, whichis embodied in the Ceprate SC System, takes advantage ofmonoclonal antibodies for selectivity and the strong affinity betweenavidin (a protein) and biotin (a vitamin) to allow cell selection to beperformed in a high-volume, continuous-flow, closed processingsystem.

In the Ceprate SC System, biotin molecules attached to monoclonalantibodies (which are themselves selective for the cells of interest)are introduced into a cellular mixture.

The biotin-conjugated antibodies bind selectively to the target cells.The resulting antibody-cell suspension is then rapidly passed througha column containing avidin-coated beads. The strong affinity betweenbiotin and avidin causes the biotin-linked target cells to adhere to theavidin-coated beads.

This technique can be used to either positively select cells of interestor negatively deplete unwanted cells. In a positive selectionapplication, unmarked cells are washed through the column, thencaptured cells are removed by gentle agitation and collected for use.

In a negative selection application, the cells, which do not adhere tothe column, are returned to the patient and the harmful cells that havebeen captured by the avidin-coated beads are retained and discarded.

The avidin-biotin binding process makes possible a continuous-flowsystem that allows high throughput of cells in a short period of timewith limited opportunity for non-target cells to bind nonspecificallyto the beads.

FDA approval, Reiter said, was based on a Phase III clinical trial inautologous bone marrow transplantation for patients with advancedbreast cancer. Data gathered during the trial demonstrated successfulengraftment of the transplanted cells. It also indicated significantdecreases in the infusional toxicity normally associated with bonemarrow transplantation.

CellPro currently is conducting a Phase III trial to demonstrate theeffectiveness of the Ceprate system for the depletion of tumor cellsfrom autologous peripheral blood for patients with multiple myelomawho are receiving stem cell transplants.

The depletion of tumor cells from autologous peripheral blood couldpotentially reduce the risk of relapse associated wit the infusion ofcancer cells along with the stem cells needed for engraftment.

In addition, CellPro recently began clinical trials using CellPro'ssecond-generation product, the Ceprate TCD T-Cell DepletionSystem. This product is used with the Ceprate SC System to furtherreduce the number of T lymphocytes in peripheral blood stem cellsused for allogeneic transplantation.

Mark Ostro, an analyst with UBS Securities Equity Research in NewYork, gives conservative estimates for initial sales of the Cepratesystem. "We have assumed a relatively slow ramp-up of sales due tothe time it will take CellPro to install the hardware and trainoperating technicians in the 300 U.S. transplant centers," Ostro said.

Ostro projects, however, that the total sales will amount to $11million in fiscal year 1997 (ending in March 1997), including $1.2million in U.S. sales and $9.4 million in European sales, $24 millionin fiscal year 1998, $56 million in fiscal year 1999 and $97 million infiscal year 2,000.

"Based upon projected fiscal year 2,000, earnings of $1.75 per shareand using a 30x P/E multiple and a 25 percent discount factor, wehave a 12-month price target of $34," Ostro said.

"Ceprate should be the first product to be introduced into the U.S.market for the isolation of stem and progenitor cells, probably at leasttwo years ahead of its nearest competitors, Amgen and Baxter," Ostrosaid.

CellPro's stock (NASDAQ:CPRO) closed Monday at $13.375, down$0.875. n

-- Frances Bishopp

(c) 1997 American Health Consultants. All rights reserved.