Chiroscience Discovers Novel Bone Gene: Potential to Develop New Treatments to Reverse Osteoporosis.

SEATTLE and CAMBRIDGE, England--(BW HealthWire)--May 18, 1999)--

Chiroscience R&D, the drug discovery and development business of Chiroscience Group plc, today announced the discovery of a gene that may prove a turning point in the development of new treatments for osteoporosis.

Chiroscience scientists based in Seattle have succeeded in identifying a novel gene coding for a protein that appears to be involved in the control of bone density, said Dr. John Padfield, Chief Executive of Chiroscience Group plc. This bone mass gene is altered in all patients suffering from the rare bone growth disorder known as sclerosteosis. Sclerosteosis causes bones to continue to gain mass throughout the affected individual's life. This results in a bone density many times greater than normal, making their bones nearly impossible to break or fracture. Sclerosteosis appears only with frequency among the Afrikaaner population in South Africa.

The discovery of the bone mass gene is the result of many years of painstaking collaborative work between the Chiroscience scientific team and academic researchers at the University of Cape Town in South Africa, Dr. Padfield said. Leading researchers Dr. Peter Beighton and Dr. Herman Hamersma in South Africa, in collaboration with Chiroscience, laid the foundation for the discovery of the gene through interviewing and collecting samples from the families of individuals with sclerosteosis.

"The research by our colleagues in South Africa led us to believe that the gene responsible for sclerosteosis was a very exciting target," said Jeff Van Ness, one of the project's founders. "We felt that this could be the key to restoring bone loss, and potentially help millions around the world who suffer from osteoporosis."

The genetic samples collected in South Africa provided the starting point for the Chiroscience scientists' search for the sclerosteosis gene. The initial step was to extract genetic markers from the chromosomes of individuals carrying the gene using a genome wide scan. A genetic map of the region was then developed and compared to similar maps from the DNA samples of non affected families. This comparison allowed the Chiroscience team to narrow the area of DNA that was sequenced in order to find the gene, Dr. John Latham, who now heads the project, said.

Over the last six months the scientists in Seattle have worked to fully characterize one gene that contained a single base pair of DNA that had mutated, with the same mutation occurring among all affected patients. This mutation is believed to cause the gene to dysfunction and lead to an inability to correctly regulate bone growth.

Dr. John Padfield, commented: "The discovery of the bone mass gene provides Chiroscience with a proprietary biological target from which to develop novel treatments for osteoporosis. Our next goal is to design a compound that mimics the action of this gene and create a drug that can actually stimulate bone growth. This discovery is a major breakthrough for the company and provides the ideal opportunity for Chiroscience to fully capitalize on its 'gene-to-drug' development expertise. "

Osteoporosis occurs when an individual loses bone matter more rapidly than it is replaced. This results in low bone mass and structural deterioration of bone tissue leading to bone fractures. Most sufferers only first realize that they have osteoporosis when they break a bone. Current treatments have limitations as they only help to slow bone loss and prevent further development of the disease; at present there are no treatments that can substantially reverse the effects of osteoporosis.

In the U.S. alone, 10 million people have osteoporosis, and 18 million have low bone mass, increasing their risk for the disease. Osteoporosis is responsible for more than 2.5 million bone fractures each year in the U.S. and Europe. Estimated direct expenditure (hospital and acute inpatient costs) for osteoporosis and related fractures is $14 billion annually in the U.S., and in Europe exceeds $10 billion.

"We believe that this bone mass gene controls bone mineral density in humans," added Dr. Latham. "Based on this finding, there is a real opportunity for a novel treatment to be developed that will actually build strong bone. For Chiroscience and our international research partners, this is an exciting discovery; for those suffering from osteoporosis, this is the best news in years."

The discovery is also good news for the Afrikaaner population. Sclerosteosis is a disfiguring, and often fatal, disorder for which there is no cure. Afrikaaners have for many years hoped for a genetic test and there is now a prospect for one being developed.

Chiroscience is an emerging pharmaceutical company with two distinct parts: Chiroscience Research and Development, the company's core pharmaceutical products business, and the specialist service businesses, ChiroTech and Rapigene.

Chiroscience R&D uses its "gene-to-drug" skills base to discover and develop innovative small-molecule pharmaceuticals for the treatment of inflammation, pain, cancer, osteoporosis and auto-immune disease. Chirocaine, its long-acting local anaesthetic, is close to market.

ChiroTech is a profitable business that is a world leader in the provision of specialist chiral chemistry services and products. Its customer base of major pharmaceutical companies is growing rapidly. Strategic alliances with a number of global partners have broadened the range of products and services that Chirotech can offer.

Rapigene is commercializing its Masscode system for high-throughput genetic measurement and analysis. Rapigene intends to use Masscode to offer a rapid, cost-effective analytical service to life science customers.

For more information on osteoporosis, please contact:

The National Osteoporosis Foundation 

www.nof.org

or

The Endocrine Society

www.endo-society.org

or

National Institutes of Health (NIH)

Osteoporosis/Related Bone Diseases -- National Resource Center

1-800-624-BONE

fax [phone]

TTY 202/466-4315

e-mail: [e-mail]

www.osteo.org