Stoke Therapeutics Inc. (Nasdaq: STOK) has pulled in Biogen (Nasdaq: BIIB) to help it develop and commercialize a treatment it’s working on for Dravet syndrome, a rare, debilitating form of epilepsy that affects children.

Biogen (NASDAQ:BIIB) and Stoke Therapeutics (NASDAQ:STOK) said on Tuesday they are collaborating to develop and commercialize zorevunersen, an investigational treatment for Dravet syndrome, in territories outside the United States,

Biogen and Stoke Therapeutics have signed a partnership agreement to co-develop and sell Stoke’s experimental treatment for Dravet syndrome, a severe form of epilepsy, outside the U.S., the companies said this morning.