 In 2002, Neurocrine entered into an agreement with Pfizer to develop the drug.Indiplon was originally scheduled for release in 2007, when Sanofi-Aventis' popular hypnotic zolpidem lost its patent rights in the United States and thus became available as a much less expensive generic.In 2002, Neurocrine Biosciences had entered into an agreement with Pfizer to co-market indiplon in the US, in a deal worth a potential $400mn.