Company's Own Western Blot Assay Remains a Valuable Tool

In Verifying Removal of Infectivity

    SEVILLE, Spain, May 22 /PRNewswire/ -- Continuing the industry-leading
 work in the area of plasma purification processes, Bayer Biological Products
 (BP) scientists today reported the capacity to remove the pathogenic form of
 human prion protein during plasma protein manufacture simulations.  In an
 abstract presented at the XXV International Congress of the World Federation
 of Hemophilia (WFH) in Seville, Spain, Bayer BP scientists shared data showing
 the prion protein that causes variant Creutzfeld-Jakob Disease (vCJD) can be
 removed by purification processes used in the manufacture of blood protein
 products, reducing the theoretical risk of transmission through use of these
 products.
     The Western blot assay, quicker and cheaper than conventional bioassays,
 was licensed to BioReliance Corporation so other manufacturers of biological
 products could more quickly and efficiently assess manufacturing processes for
 prion protein removal.  This research is the next step in a series of
 advancements reported by Bayer BP scientists over the last several months.
 Key to this work is the continued demonstration that the Western blot assay,
 developed by Bayer BP, used for detecting pathogenic prion proteins, is
 valuable in estimating the removal of TSE infectivity.
     "Bayer remains committed to further increasing our ability to ensure all
 our biological products are safe from any theoretical threat posed by prions,"
 said Dr. Gunnar Riemann, executive vice president, Bayer Corporation, and
 president, Bayer BP Business Group.  "When patients receive a Bayer BP
 product, we want them to have peace of mind, knowing this is the safest
 product available."
     The lead author on the abstract, Chris Stenland, Ph.D., senior scientist,
 Bayer BP, participated with other clinical, regulatory, and scientific
 experts, in a symposium held May 20 during the WFH congress titled "Where Do
 We Stand on vCJD: An Up to the Minute Look at vCJD and Clotting Factor
 Concentrates."
     "Although no cases of variant CJD or other transmissible spongiform
 encephalopathies have been reported from use of therapeutic plasma proteins,
 we remain diligent in our work to prevent this possibility," said Dr.
 Stenland.  "The results from our studies demonstrate that plasma manufacturing
 processes have a significant potential to remove these prions."
 
     Pathogenic Role of Prions
     The pathogenic form of prion proteins (PrPs) has been associated with
 fatal diseases, including mad cow disease in cattle, scrapie in sheep, and the
 human disorders Creutzfeldt-Jakob Disease (CJD), Gerstmann-Straussler-
 Scheinker, Kuru, and fatal familial insomnia.  To date, no clinical evidence
 exists to support the transmission of human transmissible spongiform
 encephalopathies (TSE), such as CJD, by blood or blood-derived products.
 However, recent evidence from experimental animal models suggests that blood
 has the potential to contain TSE infectivity and cross-species transmission
 may occur.  For these reasons, biopharmaceuticals, including human plasma
 derivatives, recombinant proteins grown in media containing fetal calf serum,
 and human-derived products containing bovine additives, have a hypothetical
 risk of containing TSE infectivity, increasing the importance of continued
 advancements in this field of research.  Bayer scientists are working toward
 reducing this theoretical risk for transmission even further.
     Regulatory agencies require manufacturers to demonstrate removal or
 inactivation of pathogen impurities, such as viruses, from biological
 products.  Although agencies currently do not require documentation of prion
 protein or TSE removal, they continue to follow the science in this area
 closely.  Moreover, because methods that effectively inactivate the infectious
 TSE agent also destroy most soluble therapeutic proteins, the removal of
 prions remains the most viable strategy for addressing the hypothetical risk
 of TSE transmission.  Assessing the ability of a particular manufacturing
 process to remove pathogenic prions is an important step in addressing this
 hypothetical risk.  The methodology developed by Bayer allows researchers to
 quickly evaluate whether a particular manufacturing process is capable of
 removing TSE infectivity.
 
     About Bayer
     Best known for its flagship product, Bayer Aspirin, Bayer Corporation
 produces a broad range of health care, crop protection, polymer, and chemical
 products that help diagnose and treat diseases, purify water, preserve local
 landmarks, protect crops, advance automobile safety and durability, and
 improve people's lives.
     Headquartered in Pittsburgh, Bayer Corporation had sales of $10.1 billion
 in 2001, and is one of Fortune magazine's Most Admired Companies.  The company
 employs 21,500 people.  It is a member of the worldwide Bayer Group, a
 $27 billion international health care and chemicals group based in Leverkusen,
 Germany.  The Bayer Group stock is a component of the DAX and is listed on the
 New York Stock Exchange (ticker symbol: BAY).
     Information about Bayer Biological Products Business Group can be found at
 http://www.bayerbiologicals.com.
 
     Forward-looking Statements
     This news release contains forward-looking statements based on current
 assumptions and forecasts made by Bayer Group management.  Various known and
 unknown risks, uncertainties, and other factors could lead to material
 differences between the actual future results, financial situation,
 development or performance of the company, and the estimates given here. These
 factors include those discussed in our public reports filed with the Frankfurt
 Stock Exchange and with the U.S. Securities and Exchange Commission (including
 our Form 20-F).  The company assumes no liability whatsoever to update these
 forward-looking statements or to conform them to future events or
 developments.
 
 

SOURCE  Bayer Biological Products