The European Medicines Agency on April 28th provided the strongest hint yet that the highly-anticipated Sanofi-Aventis weight-loss drug rimonabant may be marketed under two different names: Acomplia in Europe, and Zimulti in the United States.

The signal came when a key committee of the European Medicines Agency (EMEA) simultaneously recommended approval of Acomplia (rimonabant) and Zimulti (rimonabant), citing the same clinical trials and using identical language in the approval announcements.

These pretty clearly are not, as some reports initially erroneously suggested, two different Sanofi drugs. In its press release following the EMEA decision, Sanofi never even mentioned Zimulti.

"Following European marketing authorization, Acomplia will be available in European Union countries for prescription as a 20mg tablet to be taken once daily," the drug's developer Sanofi-Aventis said. "First launches are anticipated during the second half of 2006."

A further indication that Zimulti is simply a different trade name and not a different drug came in the EMEA news release announcing the recommendation for approval of Acomplia and Zimulti.

The release reported that the EMEA review for Acomplia began on 18 May 2005 with an active review time of 202 days, while the EMEA review for Zimulti began on 15 September 2005 with an active review time of only 85 days.

Eighty five days would be a remarkably short time for EMEA review of a novel drug.

Ever since the U.S. Food and Drug Administration in February delayed approval of Acomplia, speculation has been rampant that one of the unspecified issues holding up action was the U.S. regulator's concern over the drug's name.

The speculation was fueled in March when an analyst asked Sanofi officials why they generally referred to the drug as rimonabant and no longer used the name Acomplia.

Sanofi executive vice president Hanspeter Spek told analysts "we have so far no clearance for Acomplia as a trademark in the U.S.," and said "there is a clear option" Sanofi would go with a different trade name for rimonabant in the United States though no decision has been taken.

While Acomplia is registered as a U.S. trademark by Sanofi, insiders have suggested that the problem lies not with the U.S. Patent and Trademark Office but with the FDA, which believes the name Acomplia may put too positive of a spin on this new drug. The FDA has demonstrated in the past that it has the power to force a name change.

But while it may be Zimulti in the United States, Sanofi gave every indication on April 28th that it planned to market the drug as Acomplia in Europe. The Sanofi news release announcing the EMEA approval repeatedly referred to the drug as Acomplia.

The Wall Street Journal subsequently reported on April 29th that an unidentified Sanofi spokesman confirmed the company plans to use the name Acomplia in Europe, but declined to comment on the United States.

In the absence of any further clarification from Sanofi, the tea leaves appear to suggest more strongly than ever that Zimulti may be the name rimonabant ultimately is marketed under in the U.S.