On Tuesday I posted about Wyeth/Solvay's subtle bifeprunox advertisement masquerading as a CME activity in Psychiatric Times. Their karma has caught up with them, as the FDA just rejected their application for approval of the new antipsychotic.
According to reports, FDA was unimpressed with two acute-treatment controlled studies, both of which showed that bifeprunox performed more poorly than existing atypicals. You can read a review of these efficacy trials here. One study compared bifeprunox 20 mg/day with risperidone 6 mg/day. After 6 weeks, bifeprunox lowered PANSS scores by 11.3, wherease risperidone posted a more robust symptom reduction of 15.6 (statistical significance was not reported). In a second study, bifeprunox with slammed even more harshly by Zyprexa (olanzapine). Also a 6-week study, bifeprunox 20 mg/day yielded a PANSS improvement of 13.8 vs. Zyprexa 15 mg/day's 22.0. In that trial, only Zyprexa significantly separated from placebo.
As a psychiatrist, I'm not too disappointed, because bifeprunox is essentially a me-too version of Abilify (aripiprazole). Like Abilify, bifeprunox is a partial dopamine receptor agonist, meaning that it can either block or stimulate dopamine receptors. Thus, bifeprunox appears to be a less effective version of Abilify (though no head to head trials have been reported). We don't need it.