Aug. 29 (Bloomberg) -- Sanofi-Aventis SA, the world's third biggest drugmaker, said its experimental anti-craving pill, rimonabant, helped obese patients lose about 19 pounds and trim 3.5 inches from their waists in a study.

In a 1,507-patient clinical trial presented today at the European Society of Cardiology meeting in Munich, 39 percent of patients taking a daily 20 milligram pill of rimonabant for one year lost more than 10 percent of their body weight, compared with 12 percent of patients on placebo. Rimonabant is designed to block brain signals that control cravings.

The study is the largest to date supporting rimonabant's potential to treat obesity, one of heart disease's biggest risk factors. Data further showed rimonabant had positive effects on cholesterol levels. Paris-based Sanofi-Aventis is also testing rimonabant against smoking, and estimates the medicine may exceed 3 billion euros ($3.6 billion), in peak annual sales. The company plans to sell rimonabant under the name Acomplia.

``Obesity is associated with so many risk factors, especially cardiovascular, that any effort we can make to reduce it is worthwhile,'' Luc Van Gaal, associate professor of endocrinology at University Hospital in Antwerp and a lead researcher on the study, said in an interview. ``A 5 to 10 percent reduction of weight leads to a reduction of risk factors by 25 percent to 30 percent.''

The study compared three groups of patients -- those taking a 5 milligram rimonabant pill, another on a 20 milligram pill and those taking placebo. Patients in all groups were put on a low- calorie diet. The drop-out rate was 39 percent for the high rimonabant dose compared with 42 percent in the placebo group.

A small number of patients cited side effects as the reason for leaving the trial, researchers said.

Obesity Epidemic

An estimated 1 billion people around the world are overweight or obese -- more than 20 percent over their ideal weight -- according to the World Health Organization. About 130 million are obese or overweight in the U.S., the world's biggest drug market. Obesity also poses a major risk for chronic diseases such as diabetes, hypertension, stroke and some forms of cancer.

Sanofi said it plans to file for U.S. Food and Drug Administration approval of rimonabant in the second quarter of 2005, after completing four more trials. The drug will have been tested in 13,000 patients by then, the company said.

``It will be very widely prescribed if found safe and effective in the remaining trials that are due to come out over the next year or two,'' said Christopher Cannon, a cardiologist at Brigham and Women's Hospital in Boston and an associate professor of medicine at Harvard University.

Side Effects

Patients taking rimonabant at the higher dose lost an average 19 pounds compared with 8 pounds for those on placebo. The most common side effects seen among patients were nausea, diarrhea and dizziness, which were temporary and mild, researchers said.

Data from a U.S. study last March showed rimonabant helped obese patients lose an average of 20 pounds, compared with five pounds for patients on placebos.

Rimonabant is the first drug of its kind designed to block receptors of a substance called cannabinoid 1, suppressing the urge to overeat and other cravings. CB1 receptors are found in the brain and in fat cells, which also play a role in the complex signaling system urging the body to eat more than it needs.

Sanofi wants to persuade doctors that rimonabant is more than a weight-loss drug by keeping the focus on the medicine's heart benefits. Results showed the medicine raised levels of HDL, the so-called good cholesterol, by 27 percent.

``This is a figure not seen so far, not even with statins,'' a class of drugs commonly prescribed to reduce levels of bad cholesterol, Van Gaal told reporters during a press conference.

Tobacco Cravings

Rimonabant also helps control tobacco cravings, researchers said. In a study earlier this year, the pill helped smokers quit without weight gain in a study earlier this year. Smoking is a leading cause of death and a risk factor for heart disease.

Though rimonabant results are impressing doctors, many want to see more health initiatives encouraging overweight patients to change their lifestyle habits, said Otto Smiseth, a professor of medicine at the University of Oslo.

``Rimonabant shows a substantial weight reduction, and if that's possible without side effects it could be promising,'' Smiseth said in an interview on the sidelines of the press conference on the study. ``I have concerns about the idea you just buy a drug and that's it, buying weight reduction instead of changing lifestyle habits.''

The company has been working with health authorities to get an FDA approval that reflects the drug's use in heart disease, Douglas Greene, Sanofi's vice president for regulatory affairs said in an interview last week.

To contact the reporter on this story: Angela Zimm in London at at azimm@bloomberg.net

Last Updated: August 29, 2004 06:05 EDT