Taranabant a new competitor to rimonabant acomplia

Diet drug taranabant, Merck's competitor to the Sanofi-Aventis drug rimonabant (Acomplia / Zimulti), is now entering the final months of a two-year international study with 2,400 participants.

Anecdotal reports from participants in the Phase III trial of taranabant, otherwise known as MK-0364 or L-000899055, continue to be encouraging, and Merck has said it expects to file for approval to market the diet drug in the United States in spring 2008.

But there have been no presentations of interim results of the trial to scientific meetings and Merck has had little to say about taranabant.

Some suggest Merck has drawn some important conclusions about how-not-to-gratuitously-alienate-the-FDA from recent experiences of Sanof, which trumpeted one exciting result after another from clinical trials of rimonabant only to find things moving slower and slower at the regulatory agency.

With millions of Americans eagerly anticipating approval of rimonabant, the FDA repeatedly delayed action, and Sanofi finally pulled back its application in June -- ending hopes of early approval -- after an FDA advisory panel recommended the diet drug not be marketed until safety issues are resolved.

Meanwhile, taranabant -- which started out several years behind rimonabant -- moves quietly through the clinical trial process. The Phase III trial, which began enrolling participants in fall 2005, will be drawing to an end in the final quarter of this year, with contracts for researchers ending in early 2008.

Final results from this trial, where participants were rerandomized for the second year in an effort to determine what dose is needed to keep off weight lost in the first, are not expected until spring, and there has been no hint Merck will bring interim news to the Obesity Society annual meeting in October.

Diet Drug Acomplia (Rimonabant) Gets Reprieve in Europe

Diet drug Acomplia (rimonabant) was discussed by European regulators at their June meeting this week, but the only decision reached was to discuss the matter again at their July 16-to-19 meeting.

The Committee for Medicinal Products for Human Use of the European Medicines Agency, which approved Acomplia for sale in Europe more than a year ago, said it will continue to review data on the diet drug, which has been purchased by more than 100,000 Europeans.

The agency's discussion of Acomplia this week followed the overwhelming vote by the U.S. Food and Drug Administration's Endocrinologic and Metabolic Drugs Advisory Committee last week to recommend against sale of the diet drug in the United States based on currently available safety date.

The advisory panel's vote was based on newer data presented by FDA staff -- including data from post-marketing reports on usage in Europe. The FDA is expected to go along with that recommendation in the next several weeks.

While rimonabant acomplia for the moment will remain on sale in European Union countries on the same basis as it has been for the past year, the EMEA is expected to want to continue hearing about neurological and psychiatric side effects associated with the drug, including depression and suicidality.