Biogen, Stoke Therapeutics announce zorevunersen commercialization agreement

Biogen (BIIB) and Stoke Therapeutics (STOK) announced a collaboration for the development and commercialization of zorevunersen, a potential disease modifying medicine in development for the treatment of Dravet syndrome, in all territories outside the United States, Canada, and Mexico. Zorevunersen is an investigational antisense oligonucleotide that targets the SCN1A gene, the underlying cause of most cases of Dravet syndrome. Stoke recently announced plans to initiate a global Phase 3 registrational study of zorevunersen following successful alignment with regulatory agencies in the United States, Europe, and Japan. The study is on track to initiate in the second quarter of 2025, with a pivotal data readout expected in the second half of 2027, which is anticipated to support global regulatory filings. Stoke will continue to lead global development and retains exclusive development and commercialization rights for zorevunersen in the United States, Canada, and Mexico. Biogen receives exclusive rights to commercialize zorevunersen in the rest of the world. Upon closing of this transaction, Stoke will receive an upfront payment of $165M. The parties will share external clinical development costs for zorevunersen. Additionally, Stoke may receive up to $385M in development and commercial milestone payments. Stoke will also be eligible to receive tiered royalties ranging from low double digits to high teens on potential net sales in the Biogen territory. Stoke has also granted Biogen an option to license rights outside of the United States, Canada, and Mexico to certain future follow-on ASO products targeting SCN1A, in exchange for separate milestone, cost sharing, and royalty considerations.