The new obesity drug rimonabant (Acomplia), which made headlines in November with two-year trial results showing it helped people lose significantly more weight than a placebo, got a new boost today (March 8th) as researchers reported another round of highly encouraging two-year results from a second major study.

The trial not only reinforced earlier results showing Acomplia helped overweight individuals shed pounds and keep most of the weight off, but again strongly suggested that Acomplia helps reduce the dangerous visceral fat in the abdominal cavity linked to diabetes and heart disease.

Dr. Luc Van Gaal, a professor at University Hospital Antwerp in Belgium who is lead researcher on the study, said patients in the trial who remained on the higher 20mg dose of Acomplia for the full two-year period on average lost 19 pounds and reduced their waistline by almost three inches.

"We have a new drug that may help not only from the weight and waist point of view, but also help with cardiovascular risk factors," Van Gaal said. "The data is consistent for all studies that have been performed for this new drug. This is a breakthrough."

"This is a remarkable study -- a landmark study," said Dr. Julius M. Gardin, chief of cardiology at St. John Hospital & Medical Center in Detroit. "And it is heartening to see that the safety profile is really quite good.

Riding the crest of the positive new results, officials of drug developer Sanofi Aventis reiterated plans to file for marketing approval with both with the U.S. Food and Drug Administration and in Europe in the second quarter of this year, potentially enabling them to begin offering the drug to patients in 2006.

Results from the study entitled, Effect of Rimonabant on Weight Reduction and Weight Maintenance: RIO-EUROPE, were presented on March 8th at the American College of Cardiology's 2005 Scientific Meeting in Orlando.

In reporting two-year results, researchers pointed out that data for those on the 20 mg dose of Acomplia in RIO:EUROPE was very similar to two-year data for participants in RIO:NORTH AMERICA reported last November.

Almost one-third of patients in both trials finished the two-year study 10 percent lighter than when they began, though the new data showed participants gaining a couple of pounds back in the final weeks of the study.

Waist circumference of RIO:EUROPE trial participants on the 20 mg dose after two years was reduced by 2.9 inches, again very similar to the 3.1 inch reduction in waist size for patients in the RIO:NORTH AMERICA trial.

Patients in both studies taking Acomplia also had significantly improved levels of HDL (good cholesterol) after two years, as well as lower triglycerides and improved insulin sensitivity, according to the researchers.

Researchers at the Orlando meeting seemed to be placing more emphasis than at previous presentations on Acomplia's potential for reducing cardiovascular risk factors, independent of its role in helping reduce weight.

Adverse side effects reported among participants in the RIO:EUROPE study were similar to those reported in RIO:NORTH AMERICA, with the most common -- nausea, dizziness, diarrhea and vomiting -- described as mild and short-lived, and much less frequent in the second year.

But psychiatric disorders, most notably depression, were cited as a factor in the discontinuance of the drug by almost three percent of trial participants on the higher Acomplia dose, and this seems certain to get more attention during the regulatory approval process.

A cautionary note along these lines was injected by Gardin, who noted that safety experience was still based on a fairly small number of study participants taking the drug for a relatively short time..

Gardin also pointed out the slight average increase of weight among those taking Acomplia toward the end of the two-year trial period.

"As we all know, obesity is not just a two-year problem," Gardin said. "We certainly will want to see more studies to see what happens long term."

Other sources: Medical Week staff