Optimism about prospects for the new diet drug rimonabant (Acomplia) surged on the news that manufacturer Sanofi-Aventis plans to present data from two years of clinical trials, rather than one-year data, at the annual scientific meeting of the American Heart Association on November 9th in New Orleans.

One-year results from clinical trials published earlier this year showed that many patients who stayed on rimonabant for a year lost more than 10 percent of their body weight, while the drug also significantly increased levels of “good” HDL cholesterol.

While further results had been expected to be presented at the American Heart Association meeting, analysts viewed news that Sanofi-Aventis would be presenting two-year data as a sign that rimonabant is continuing to produce encouraging results in the trials underway.

"They have raced and managed to get the two-year data out and it is being presented at a late-breaking session, so the implication from that is it is positive," said Commerzbank analyst Marc Booty.

In addition to further data on effectiveness, researchers will also be scrutinizing information on side effects from the longer use of rimonabant. Adverse side effects ultimately have dashed high hopes once held for several earlier diet drugs.