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.

The partnership splits the rights to Stoke’s epilepsy antisense oligonucleotide, with up to $385 million in potential payments due to Stoke.

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.