Pfizer Inc said that it is returning to Neurocrine Biosciences, Inc. the development and marketing rights for Indiplon, a medicine in development to treat insomnia. This includes both the collaboration to develop and co-market Indiplon in the US as well as Pfizer's exclusive license to develop and market Indiplon outside of the US, according to an official release.

Having been agreed to terminate the deal, Neurocrine Biosciences will reacquire all worldwide rights for Indiplon capsules and tablets and will independently develop Indiplon for approval and commercialization.

Neurocrine will meet with the Food and Drug Administration (FDA) to finalize development plans for the resubmissions of each Indiplon NDA and plans to commercialize Indiplon as quickly as possible upon approval.

The Company plans to review various business and commercial alternatives to expedite successful commercialization of Indiplon. As part of the termination provisions of the agreement, Pfizer will continue to support Indiplon for a period of up to 180 days to ensure a smooth transition.

Indiplon is a non-benzodiazapine agent that acts on a specific site of the GABA-A receptor. Indiplon has been shown to bind selectively to the specific subtype of GABA-A receptors. These receptors within the brain are believed to be responsible for promoting sleep.