Merck & Co. and Portola Pharmaceuticals have entered into a global collaboration and licence agreement to develop and commercialise betrixaban, for the treatment and management of multiple aspects of cardiovascular disease.

Betrixaban is an investigational oral Factor Xa inhibitor anticoagulant, currently in phase II clinical development for the prevention of stroke in patients with atrial fibrillation (SPAF).

Merck Research Laboratories senior-vice president and franchise head Atherosclerosis and Cardiovascular, Luciano Rossetti, said that Betrixaban has the potential to be a significant medicine in the Factor Xa inhibitor class.

“This agreement reinforces Merck’s focus on developing an innovative portfolio of products for the treatment and management of multiple aspects of cardiovascular disease,” Rossetti said.

Merck will pay Portola an initial fee of $50m in return for an exclusive worldwide licence to betrixaban. Portola will then be eligible to receive additional cash payments of $420m as well as double-digit royalties on worldwide sales of betrixaban, if the drug is approved.

Merck will assume all development and commercialisation costs, including the costs of phase III clinical trials.

Portola has also retained an option to co-fund phase III clinical trials in return for additional royalties and to co-promote betrixaban with Merck in the US.