SEATTLE -- CellPro Inc. said Monday that its cell-selectionprocess that holds promise for use in genetic therapy and forimproved bone marrow transplants was awarded a patent inEurope.

Competing cell-selection methods have attracted keen interest-- and at least one patent suit -- among a few U.S. companies.Seattle-based CellPro in April sued two larger rivals, BaxterHealthcare Inc. and Becton Dickinson & Co., seeking toinvalidate three U.S. patents describing the monoclonalantibody to the CD34 marker molecule on the surface of stemcells. CellPro had previously attempted to negotiate rights tothe U.S. patents, which were licensed to Baxter and Becton byJohns Hopkins University.

However, the European patent announced Monday and theexisting U.S. patents cover different approaches and "don'tnecessarily impinge" each other, Lee M. Parker, CellPro'sdirector of investor relations, said Monday.

The European patent announced Monday, No. 0260280, wasawarded on May 13 to the Fred Hutchinson Cancer ResearchCenter of Seattle, which exclusively licensed worldwide rightsto the technology to CellPro in 1989. U.S. patent applicationsare pending, Parker said.

Patents and good clinical results will likely be key factors inthe commercial competition to open up a potentially wide arrayof applications for cell-selection technology.

"CellPro has gone a big way toward applying this stem celltechnology in two clinical areas" for bone marrow transplantsand gene therapy, said Cynthia Robbins-Roth, editor of themonthly BioVenture View of San Mateo, Calif.

The FDA has approved Phase III clinical trials of its Ceprate SCStem Cell concentration systems at five medical centers inconjunction with autologous bone marrow transplant to treatnon-Hodgkin's lymphoma and recurring breast cancer, Parkersaid.

CellPro announced in March two FDA-approved gene therapytrials using Ceprate. One trial at the University of Texas MDAnderson Cancer Center is using Ceprate to enrich normal stemcells from patients with chronic myelogenous leukemia (CML)for autologous bone marrow transplants. Another gene therapytrial is designed to cure adenosine deaminase deficiency.

Baxter has targeted trials of a bone purification process fortreating pediatric lymphoma.

By attracting functional cells, CellPro claims that the approachoffers "a significant improvement over previous approaches"that don't capture pure cell populations and are not designed tocollect viable cells. The newly patented process enhances cellrecovery, yielding enriched, or even pure, viable cells, thecompany said.

In bone marrow transplants, CellPro's cell-selection process,using a MAB for the CD34 marker, resulted in fewer cancercells being reinfused into patients and a quicker recovery ofthe patient's own blood marrow, according to study resultsannounced last month. The study also showed that thetreatment reduced common side effects of bone marrowtransplants, such as nausea, vomiting, slow heart rate and highblood pressure.

As a result, the improved bone marrow transplants could beused to treat a larger number of cancer patients, Parker said.Many of the 1.5 million chemotherapy patients each year in theU.S. could be candidates for bone marrow transplants using thenew techniques. Only 12,000 bone marrow transplants areperformed annually in the U.S. now.

CellPro stock (NASDAQ:CPRO) closed unchanged Monday at $11a share.

-- Ray Potter Senior Editor

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