Merck, known as MSD outside the U.S. and Canada, and Astellas US, the U.S. subsidiary of Astellas Pharma, have entered into an agreement under which Merck, through a subsidiary, will acquire the exclusive rights to develop and commercialize the investigational intravenous formulation of vernakalant in Canada, Mexico and the U.S. from Astellas for an undisclosed fee.

Vernakalant is currently approved in more than 10 European countries, where it is marketed as Brinavess, for rapid conversion of recent onset atrial fibrillation (AF) to sinus rhythm.

Under the terms of the agreement, Merck will pay Astellas an undisclosed upfront fee. In addition, Astellas will be eligible for milestone payments associated with development and regulatory approval as well as sales thresholds achieved in Canada, Mexico and the U.S.

The drug has switched hands in the past. In October 2003, Astellas US was granted an exclusive license to develop and commercialize vernakalant in Canada, Mexico and the U.S. by Cardiome Pharma. In April 2009, Merck, through a subsidiary, was granted exclusive rights to vernakalant outside of Canada, Mexico and the U.S. for rapid conversion of acute AF to normal heart rhythm.