Pharmaprojects R&D Pipeline News Feed
Blow for Merck & Co as it terminates development of late-stage obesity drug
6th Oct 2008
Merck & Co has discontinued development of taranabant, its most advanced antiobesity agent, as data from Phase III trials showed that in addition to having greater efficacy at higher doses, the drug also produced in more adverse events.
Taranabant is a cannabinoid 1 receptor inverse agonist, belonging to the same class as Sanofi-Aventis' rimonabant (Acomplia, Slimona) which was launched in European and S American countries in 2006 for the treatment of obesity in patients with Type II diabetes, dyslipidaemia or other risk factors. Due to the risk of psychiatric side-effects associated with rimonabant's cannabinoid 1 receptor antagonistic activity, the drug is contraindicated in the EU and Argentina for use in patients with major depression or who are taking antidepressants.
Previously, the neurological effect associated with this activity was seen as a positive factor, with taranabant being investigated for use in psychiatric disorders and rimonabant being studied for use in schizophrenia. However, development in both these areas was terminated in favour of development for obesity.
Several other cannabinoid 1 receptor antagonists are currently in development for obesity, including Sanofi-Aventis' AVE-1625 at Phase III as well as surinabant and ibipinabant, both of which are currently in Phase II trials. AstraZeneca, Schering-Plough and Vernalis are also targeting the cannabinoid 1 receptor in the development of antiobesity drugs.
