Stoke Therapeutics Inc.'s stock soared 8% early Tuesday, after the company and Biogen Inc. announced a collaboration to develop and commercialize a treatment for Dravet Syndrome, a severe form of epilepsy that starts in childhood.

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 received exclusive rights to the rest of world markets.

Stoke is on track with a plan for a global Phase 3 study of zorevunersen in agreement with regulatory agencies in the U.S., Europe and Japan, which is expected to launch in the second half of 2025 and to produce pivotal data by the second half of 2027. Stoke will be entitled to an upfront payment of $165 million and may get up to $385 million in milestone payments on reaching certain development and commercial goals. The company will also be entitled to royalties ranging from low single-digits to high teens on potential sales in Biogen's territory.

"The reductions in seizures in patients already receiving standard of care medicines, together with the improvements in multiple measures of cognition and behavior, demonstrate the potential of zorevunersen as the first disease modifying medicine that addresses the underlying cause of Dravet syndrome," said Dr. Priya Singhal, head of development at Biogen.

Biogen's stock was up 1.2%.

(This is a breaking news story. Check back for updates)

-Ciara Linnane

For more from MarketWatch: http://www.marketwatch.com/newsviewer

This content was created by MarketWatch, which is operated by Dow Jones & Co. MarketWatch is published independently from Dow Jones Newswires and The Wall Street Journal.

(END) Dow Jones Newswires

February 18, 2025 08:14 ET (13:14 GMT)

Copyright (c) 2025 Dow Jones & Company, Inc.