Oct. 1 (Bloomberg) -- AstraZeneca Plc and Bristol-Myers Squibb Co. will report that a novel diabetes pill the drugmakers are co-developing helped patients control blood sugar and lose weight in a 24-week study. Doctors say they are concerned about long-term risks.

The drug, dapagliflozin, is the first in a new family of medicines known as SGLT2-inhibitors, which don’t tinker with the body’s own insulin, unlike other diabetes therapies. The medicine instead regulates blood sugar by helping the kidneys flush it from the body, an “ingenious” method of treating the disease, according to Michael Stumvoll, head of the diabetes division at the University of Leipzig in Germany.

The approach has potential drawbacks, Stumvoll said. The treatment causes a steady flow of sugar through the kidneys, which may result in a higher risk of bacterial infections and long-term stress on the organs, he said. The companies will present full results of an advanced test in patients of dapagliflozin tomorrow at the European Association for the Study of Diabetes conference in Vienna.

“It’s a brilliant idea; you don’t need to play with insulin,” Stumvoll said in an interview in Vienna. “But people will be flooded by glucose all the time, in every organ in the urinary tract. I find it difficult to believe it won’t have side effects. I’d be interested to see what happens after the urinary tract is essentially bathed in caramel for five years.”

Blood Sugar

Dapagliflozin helped control blood-sugar levels when used with metformin, a generic drug that is a standard diabetes treatment, in patients who didn’t benefit from metformin alone, according to the study, which is the third and last phase of trials generally needed for regulatory approval. A greater benefit was seen at higher doses.

Patients on the drug also on average shed about 4 kilograms (8.82 pounds), the initial data released in July showed.

“We have not seen any harmful effect on renal function in clinical trials to date,” Ken Dominski, a Bristol-Myers spokesman, said by e-mail. “Dapagliflozin is still being investigated in phase 3 trials, including controlled clinical trials of more than one year in duration, so the complete efficacy and safety profile, including genital and urinary tract infections, of dapagliflozin will continue to evolve as more trials read out.”

The treatment may bring in $1.5 billion in peak annual sales for London-based AstraZeneca and New York-based Bristol- Myers, Jefferies International analysts wrote in a Sept. 28 note. The partners are likely to beat rivals in getting dapagliflozin to market, as they have said they plan to file for approval in late 2010. GlaxoSmithKline Plc scrapped development of its competing SGLT2-inhibitor product in June, while Sanofi- Aventis SA has a treatment in earlier stages of testing.

Competitive Market

The drug would compete in the increasingly crowded market for diabetes treatments, which is valued globally at $27.3 billion. AstraZeneca and Bristol-Myers also sell Onglyza, which belongs to a class of medicines called DPP-4 inhibitors that includes Januvia, Merck & Co.’s drug with $1.4 billion in annual sales. Amylin Pharmaceuticals Inc. and Eli Lilly & Co. market Byetta, an injectable treatment in a class of drugs that imitate a hormone called GLP-1 and stimulate the pancreas to produce more insulin after meals.

Dapagliflozin is “very interesting, because it’s a completely new therapeutic target,” said Marc Evans, an endocrinologist at the University of Wales, based at Llandough hospital in Cardiff, England.

Initial Results

“Doctors will be very excited about this, one because it’s a tablet and also because of its association with weight loss,” said Evans, who has received research support from AstraZeneca, in an interview in Vienna. The infection rates, along with other potential side effects, “are the questions everyone will be looking at.”

Dapagliflozin’s initial results drew mixed reviews from analysts. The risk of infections was among the reasons Merrill Lynch analyst Graham Parry told investors on July 2 that dapagliflozin “will struggle to achieve the blockbuster sale potential that some anticipate.”

Deutsche Bank analysts said the initial findings support the drug’s potential as a useful treatment.

“The efficacy isn’t that differentiated from other products and from a market perspective it seems expectations are relatively low,” Deutsche analyst Alex Evans said in an interview from London on Sept. 30. “You can get about 4 to 5 kilos of weight loss, which if you’re a diabetic is quite significant, yet you’re much more prone to getting urinary or genital infections. So the question for a doctor would be how to balance all that up?”

To contact the reporter on this story: Trista Kelley in London at tkelley2@bloomberg.net

Last Updated: September 30, 2009 18:01 EDT