French drugmaker Ipsen has pulled the plug on a collaboration with Santhera and returned the North American and Japanese rights to the investigational Parkinson's disease drug fipamezole to the Swiss group.

Santhera has regained the rights to fipamezole, its first-in-class selective adrenergic alpha-2 receptor antagonist for the management of levodopa-induced dyskinesia in PD. In return, Ipsen will be eligible for milestone payments and royalties based on future partnering and commercial success of the drug.

The Paris-based grip's head of corporate strategy, Pierre Boulud, said the agreement will "help to leverage the drug’s value on a global basis while allowing Ipsen to focus on its rich late-stage development pipeline". Thomas Meier, Santhera's chief executive, said that in the short term, "the focus of our investments remains on our lead product Catena (idebenone) and its multiple product opportunities in neuromuscular and mitochondrial orphan indications".

Nevertheless, he insisted that "fipamezole continues to be a valuable asset in Santhera’s late-stage clinical pipeline".