Pfizer ceases anti-obesity drug development of class linked to psychiatric events
Pfizer has become the most recent company to end development of an anti-obesity compound that falls into the same class of other drugs linked to psychiatric side effects.

The New York City-based Pfizer cited “changing regulatory perspectives” in its decision to stop development of the compound referred to as CP-945,598.

The drug falls into the same class of medicines as Sanofi Aventis Pharmaceutical’s rimonabant, which had been sold under the brand name Acomplia in Europe. The Paris-based company halted sales of the drug last month on the recommendation of the European Medicines Evaluation Agency (EMEA).

Rimonabant never received approval in the U.S. In June 2007, an FDA panel unanimously rejected Acomplia on concerns the drug increases the number of psychiatric events like depression and suicidal thinking. Sanofi later withdrew its application seeking FDA approval for the drug.

On Oct. 2, Merck stopped development of its proposed drug, taranabant, which was linked to psychiatric side effects in clinical studies.

The drugs fall into the same category and block a chemical in the endocannabinoid system, a physiological system in the body believed to play a role in how the body regulates food intake. The FDA has expressed concerns that blocking the same chemical could increase the risk for other problems, including mood disorders and neurodegenerative disorders, such as multiple sclerosis.

“While confident in the safety of the compound, we believe that this is the appropriate decision based on all available information regarding this class of agents, as well as recent discussions with regulatory authorities,” Martin Mackay, Pfizer's president of global research and development, said.