Pfizer ends testing obesity drug on account of risk of US non-approval

Drug maker Pfizer Inc. has said it is going to put an end to testing an obesity drug on account of the risk of approval by the US being slow, expensive, and risky.

By doing so, Pfizer is following in the footsteps of other drug companies who have taken similar measures. Pfizer has decided not to put any more money into new human tests that the US Food and Drug Administration (USFDA) is likely to ask for, according to a statement by the New York-based company.

The obesity drug, known by the chemical name CP-945,598, was in the final stage of a three-stage testing process needed for market clearance by the USFDA. Reports said that analysts predicted annual sales for the drug at over $500 million.

Obesity medicines basically block the same brain receptor that makes marijuana smokers hungry. 

Earlier, Sanofi-Aventis SA's drug was rejected by the FDA in June 2007. Drug manufacturer Merck & Co quit also stopped developing its version last month. Reports had said that analysts were of the opinion that annual sales of anti-obesity drugs would be in excess of $3 billion. Studies by Merck and Sanofi were reported to have found that their versions of the drug could have links to suicides and depression. 

Bristol-Myers Squibb Co. is now the last major drug company to be still developing a similar medicine, Bloomberg said.

In its statement, Martin Mackay, Pfizer's president of research said, ''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. As part of our ongoing portfolio prioritization, we will refocus research and development resources on high-priority therapeutic areas that address an unmet medical need and have a high probability for success.''

Last month, the European Medicines Evaluation Agency (EMEA) had recommended the suspension of the anti – obesity drug rimonabant, better known by its brand name Acomplia on account of concerns that it may increase depression, sleep disorders, anxiety and aggression in some overweight or obese patients. (See: Sanofi's anti-obesity drug Acomplia pulled out of EU)