If recent regulatory decisions in the obesity space have given a renewed sense of optimism in the United States, the opposite is true in Europe.
Firstly Vivus? Qsymia (phentermine/topiramate) was rejected for the second time by the EMA's Committee for Medicinal Products for Human Use (CHMP), now Arena's Belviq (lorcaserin) has had its European application pulled. With the new generation of anti-obesity agents scoring 0 from 2 in European approvals, what chance does Orexigen Therapeutics? Contrave (bupropion/naltrexone) have now?
The CHMP refused Qsymia because of concerns over long-term psychiatric and cardiovascular effects, and specifically mentioned ?that there was a high probability that, if approved, the medicine would not be used strictly for the intended patients.?
The exact reasoning why the CHMP would have rejected Belviq has not been disclosed but a cancer signal in pre-clinical studies, the lack of robust, long-term, cardiovascular data and the risk of cognitive/psychiatric side-effects may all have contributed to the likelihood of a negative opinion of the drug. Again, the fear of misuse is probably a key factor.
Contrave has much in common with its struggling competitors-to-be: it is a combination of two previously approved agents, its weight loss efficacy falls between that of Belviq and Qsymia, and it has a list concerning side-effects (including an observed increase in heart rate). However, by the time Contrave is submitted for European approval it will be unique in that it will already have some supporting, cardiovascular outcomes data. Surely by meeting the primary endpoint of acceptable cardiovascular risk (designed for FDA approval) the EMA will recognize Contrave offers a significant net clinical benefit to obese patients, and Orexigen are on to a game changer in Europe. Conversely, if Contrave fails the outcomes trial, surely it is game over.