Aripiprazole [OPC 14597, Abilitat®] is a quinolinone derivative under development as a potential antipsychotic agent. In November 2001, Otsuka announced that an NDA has been submitted to the US FDA for aripiprazole. The compound is undergoing phase III clinical testing with Otsuka in Japan and the UK.Figure. Aripiprazole [OPC 14597, Abilitat®]Aripiprazole is thought to act as a presynaptic dopamine D2 autoreceptor agonist and as a postsynaptic dopamine D2 receptor antagonist. The pharmacological profile of aripiprazole suggests that it may be effective against both the positive and negative symptoms of schizophrenia. In September 1999, Otsuka and Bristol-Myers Squibb entered a licensing partnership for aripiprazole. Under the agreement, the companies will jointly market and promote the drug, under Otsuka's trademark, in the US and European Union, and will collaborate on the completion of clinical trials. Bristol-Myers Squibb will have exclusive rights to aripiprazole in all other markets, excluding Japan and certain Asian and Middle Eastern countries. Bristol-Myers Squibb plans to conduct additional trials of new forms of aripiprazole, and in new indications.