Drug could curb effects of diabetes
Clinical trials in U.S. go well. The next step is to
test higher doses of the biological therapy on patients
Thursday, October 16, 2003
A Montreal physician who discovered a protein that could reverse the effects of diabetes is optimistic about the drug after clinical trials in the U.S. showed it is safe and well tolerated.
The next step is to test higher doses of the INGAP therapy on diabetics and to determine whether it's effective. Proctor and Gamble Pharmaceuticals is recruiting 200 people in the U.S. with Type 1 and Type 2 diabetes for a clinical trial.
"I'm very positive," said Lawrence Rosenberg, who continues to experiment with the drug on animals at Montreal General Hospital.
"The fact it appears to be safe is exciting, and the work we're doing in animals is very positive in terms of generating new insulin tissue."
The experimental drug is a form of biological therapy, stimulating the body to create new insulin-producing cells, or islets.
Diabetes occurs when the pancreas fails to release enough of the hormone insulin to break down sugar in the blood.
An excess of blood sugar can cause cardiac problems, kidney failure and blindness, and require amputations. To date, the most common treatment has been injections of synthetic insulin. There are also glucose sensitizers that make better use of insulin, and chemicals that squeeze out what little insulin exists in diabetics.
Rosenberg's INGAP therapy, however, would address the root causes of diabetes - an insufficiency of islets. INGAP stands for Islet Neogenesis Gene Associate Protein.
In the early 1980s, Rosenberg stumbled upon a human protein that triggers the creation of islets. Later on, Aaron Vinik, of the Eastern Virginia Medical School, found a way to refine the protein.
The researchers first tested a cruder synthetic version of INGAP on hamsters with diabetes, and cured 60 per cent of the animals. Rosenberg tested a purer form of INGAP last year on laboratory mice and achieved a 100-per-cent cure rate.
"In an animal model that's similar to juvenile (Type 1) diabetes, we're able to show a beneficial effect - prolonging survival and decreasing blood sugar," Rosenberg said of his latest experiments.
Rosenberg's and Vinik's research has been licensed to a Florida biotech firm, GMP Companies, which sought a partner in Proctor and Gamble.
"We're still conducting analyses of the results of the Phase 1 and 2a clinical trials, so there is no information to share externally at this point," said Gisele Galoustian, GMP's director of communications.
On GMP's Web site, the company has announced patients will be administered single daily doses of INGAP for up to 90 days. Rosenberg said in animal experiments, he has found the injections can be stopped after a certain period of time. That suggests the animals regained the ability to regulate insulin naturally in their bodies.
If all goes well - and that's a big "if" - INGAP could be approved by the U.S. Food and Drug Administration within five years, Rosenberg said. Health Canada would probably approve it a year later.
In human trials, Rosenberg said, he expects INGAP to be more effective for Type II diabetics, although it could work for Type I as well.
There are about 500,000 diabetics in Quebec, a number that's expected to double by 2025. Doctors suspect 40 per cent of diabetics are unaware of their condition.
In Type 1 diabetics, their immune systems mistakenly recognize the islets as foreign and destroy them. Type 2 diabetes mainly affects people older than 45, usually as a result of obesity. Disturbingly, however, a growing number of overweight adolescents are developing Type 2 diabetes. In both cases, their islets malfunction - partly because they are damaged by an excess of fat in the bloodstream.
Diabetics must be constantly aware of the amount of sugar in their blood. They must be careful not to administer too much insulin for fear of losing consciousness.
The standard therapies are far from a cure.
Half of all diabetics inevitably develop complications despite the medication.
© Copyright 2003 Montreal Gazette