Under the terms of the deal, Bedford, Mass.-based Stoke STOK will retain exclusive rights for the treatment called zorevunersen in the U.S., Canada and Mexico, while Cambridge, Mass.-based Biogen BIIB will receive exclusive rights to markets in the rest of the world.

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,

Under terms of the deal, Stoke will spearhead global development of zorevunersen, while Biogen will receive exclusive rights to commercialize the treatment outside of North America.

Biogen and Stoke Therapeutics have signed a deal to co-develop and sell Stoke’s experimental drug for Dravet syndrome, outside the U.S.

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 has entered a collaboration with Stoke Therapeutics to develop and and commercialise zorevunersen to treat Dravet syndrome in all territories outside Canada, Mexico and the US. Dravet syndrome is a genetic developmental and epileptic encephalopathy characterised by cognitive and behavioural impairments and recurrent seizures.

Biogen and Stoke Therapeutics have announced a partnership aimed at advancing a disease-modifying treatment for Dravet syndrome, with the deal worth $550m.

Biogen and Stoke partner on zorevunersen for Dravet syndrome, with a Phase 3 trial starting in 2025. Stoke gets $165 million upfront and milestone payments.

From my colleague Adam Feuerstein: 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.