"European regulators raised the same questions about Belviq's safety and efficacy as did FDA last year. Arena was able to assuage FDA concerns enough to get Belviq approved but no one should assume Europe plays out the same way. On a risk-reward basis, Vivus had stronger overall data for Qsymia yet the drug was rejected by Europe. Arena's case for Belviq is weaker -- efficacy is marginal and the valvulopathy safety concern lingers despite what Arena supporters claim. I'd also add European regulators aren't being hound-dogged by politicians demanding the approval of a weight-loss drug, like what happened in the U.S."