After the late stage trial of obesity drug Taranabant Merck announced the cancellation of drug development because of adverse side effects.
There was not much hope that Taranabant will be successfully developed because obesity drug development has not yet been successfull in targeting by any pharmaceutical company. However, Merck still conducted the trials to further develop Taranabant.
Obesity Cause and Help
Lately it was Sanofi-Aventis' obesity drug Acomplia (rimonabant) failing a trial because of side effects. Both Taranabant and Acomplia belong to a class of drugs named rimonabant, which work by blocking brain receptors called cannabinoid. These are the receptors that are being triggered when smoking marijuana and making the smoker feel hungry.
Taranabant reported psychiatric adverse side effects, such as anxiety and depression, and Acomplia reported suicidal thoughts and depression. This is why both drugs stopped development process.
In earlier stages of trials Taranabant showed effectiveness in helping patients lose weight, but it also reported side effects. In late stage 36 week long study the dose was increased: patients were given a 2 mg dose and they reported a 14.5 pounds excess weight loss, compared to 5.7 pounds weight loss in those taking placebo. However, despite of success, side effects also increased together with success.
Merck decided to stop Taranabant trial because the obesity treatment did not succeed, but the company is not disappointed. The side effects of Taranabant were equal to effectiveness, which means that the trials were not totally useless.