Fighting Hamburger Disease

A new drug that could prevent the harmful and potentially deadly "hamburger disease" was devised by researchers with the Canadian Bacterial Diseases Network and is currently in the final stages of clinical testing. The drug, SYNSORB Pk^®, is the lead product of SYNSORB Biotech Inc., a Canadian pharmaceutical company that develops therapeutics for diseases that at present have no effective treatment or would benefit from new ones.

SYNSORB Pk^® is designed to neutralize the toxins produced by the verotoxigenic E. coli bacteria, which is sometimes referred to as "hamburger disease" because it thrives in partially uncooked ground meat, among other places. In fact, other sources of the bacteria include fruit, vegetables, dairy products, ground water and person to person contact. Toxins produced by the bacteria in the digestive tract cause the most serious complications of infection, including bloody diarrhea, lethargy, and sometimes fever. Secondary complications include severe dehydration, hemolytic anemia, kidney damage and central nervous system failure.

Up to 100,000 people worldwide are infected by the bacteria every year, most of them children. Studies show up to 20 percent of children who contract the infection develop Hemolytic Uremic Syndrome (HUS), a severe and sometimes fatal kidney disease. While there is currently no way to predict which patients will develop kidney damage and no effective treatment for infected individuals, SYNSORB Pk^® is the most advanced product under development for the prevention of HUS.

Dr. Glen Armstrong, CBDN researcher at the University of Alberta, and Dr. Murray Ratcliffe of the former Alberta high tech company Chembiomed Ltd., led the research team that succeeded in pinpointing SYNSORBs. These synthetic sugar molecules act as alternate receptors for the harmful toxins that cause HUS. Once bound to the SYNSORBs, toxins may be excreted normally from the digestive system before they can exert cellular damage.

"The toxins are lured to the sugar that mimics the receptors on host cells. They then become trapped inside the SYNSORB that holds the sugar," says Dr. Armstrong.

The SYNSORB technology was subsequently developed in the University of Alberta laboratory of Dr. Raymond Lemieux and by a research team of the former Chembiomed Ltd., a CBDN industrial partner.

Laboratory tests with in vivo (living organism) and in vitro (artificial environment) models have shown that SYNSORBs retain their activity despite the harsh acid and enzymatic conditions of the digestive system. They can therefore be administered orally without special formulation procedures. SYNSORB Pk^® is currently in Phase III clinical trials in Canada, the U.S. and Argentina to determine the drug's efficacy in preventing the development of HUS in children suffering from verotoxigenic E. coli infections.

CBDN is one of 14 research networks funded under the Networks of Centres of Excellence Program. The three federal granting councils - the Natural Sciences and Engineering Research Council, the Medical Research Council, and the Social Sciences and Humanities Research Council - oversee and support the NCE initiative jointly with Industry Canada. In 1997-98, CBDN received $3 million from the NCE program.

For more information please visit the CBDN Web Site.