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 signalling system urging the body to eat more than it needs.
Rimonabant, which is to be eventually sold under the name Accomplia, is unique in that it was discovered to raise levels of HDL, the so-called good cholesterol as well as help smokers quit without gaining weight. Its makers Sanofi-Aventis SA, the world's third biggest drugmaker estimated the medicine might exceed $3.6 billion, (€3 billion) in peak annual sales.
According to a new Pharmacor study entitled 'Obesity,' the market will reach $2.3 billion in 2013 primarily driven by the strength of Acomplia's sales. Set to launch in 2006, Acomplia is poised to become the first antiobesity agent to achieve blockbuster status.The researchers, from the University Hospital in Antwerp, presented their findings at the European Society of Cardiology in Munich which revealed in a 1,507-patient clinical trial, 39 per cent of patients taking a daily 20-milligram pill of rimonabant for one year lost an average of 19 pounds, compared with 11 pounds for patients on 5 milligrams a day and 8 pounds for those taking a placebo.
The drug also lowered the dangerous blood fats known as triglycerides, raised HDL, or good, cholesterol and improved insulin tolerance, a risk factor for diabetes.
Luc Van Gaal, principal investigator of the RIO-Europe trial said: "The findings of the RIO-Europe trial are consistent with those of the RIO-Lipids trial announced earlier this year at the American College of Cardiology meeting."
"What is even more interesting is the effect rimonabant 20mg has on metabolic cardiovascular risk factors, which is independent of weight loss."
The study is the largest to date supporting rimonabant's potential to treat obesity, one of heart disease's biggest risk factors. However, while the results are striking they do not 'stand out' especially as they are similar to the drugs Xenical (Orlistat) by Roche and Abbbot's Meridia.
An estimated 1 billion people around the world are overweight or obese, classified as more than 20 per cent 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.