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.
An investigational antisense oligonucleotide, zorevunersen targets the sodium voltage-gated channel alpha subunit 1(SCN1A) gene, which is the primary cause of most Dravet syndrome cases.
Stoke will spearhead worldwide development and retain exclusive rights in Canada, Mexico and the US, while Biogen will commercialise zorevunersen in other regions.
Biogen has received an option to license rights to certain future antisense oligonucleotide products targeting SCN1A for territories outside these countries, in exchange for royalty considerations and separate milestones.
Stoke will receive $165m upfront from Biogen upon completion of the transaction.
The company is eligible for up to $385m in development and commercial milestone payments, plus tiered royalties on potential net sales in Biogen's territories.
The cost-sharing arrangement has Biogen covering 30% and Stoke 70% of external clinical development costs for the therapy.
Stoke Therapeutics CEO Edward Kaye stated: “With Biogen’s deep experience in neurology and track record of success in commercialising high-value disease-modifying medicines for rare genetic diseases globally, we aim to lead the treatment of Dravet syndrome into a new era by delivering zorevunersen to all patients who could benefit.
“Additionally, this collaboration provides cash flows that when combined with Stoke’s financial position, support the company through to mid-2028.”
Stoke's recent announcement of the Phase III EMPEROR trial for the therapy is set to begin in the second quarter of 2025, with pivotal data expected in the second half of 2027 paving the way for worldwide regulatory filings.
In April 2023, Biogen exercised an option to license Denali Therapeutics’ programme to develop immunotherapies for Alzheimer's disease.
