US-based biotechnology company Biogen has partnered with Stoke Therapeutics to develop and commercialise the latter’s investigational drug zorevunersen to treat Dravet syndrome.
Under the collaboration, Biogen will receive exclusive rights to commercialise zorevunersen worldwide, except in the US, Canada, and Mexico, where Stoke will retain its rights.
Upon closing, Stoke will receive $165m in upfront payment and is eligible to receive up to $385m in development and commercial milestone payments.
Stoke is also eligible to receive tiered on potential net sales in the Biogen territory.
Biogen and Stoke will share 30% and 70% of clinical development costs, respectively.
Also, Biogen can choose to license rights to certain future SCN1A-targeting ASO products outside North America, for separate milestone, cost sharing, and royalty considerations.
Biogen development head Priya Singhal said: “This collaboration broadens our late-stage pipeline with the addition of a Phase 3-ready disease modifying investigational medicine and allows us to leverage our rare disease product commercialisation expertise and global footprint.
“The reductions in seizures in patients already receiving standard-of-care medicines, together with the improvements in multiple measures of cognition and behaviour, demonstrate the potential of zorevunersen as the first disease-modifying medicine that addresses the underlying cause of Dravet syndrome.”
Zorevunersen is an experimental antisense oligonucleotide (ASO) that targets the SCN1A gene, the underlying cause of most cases of Dravet syndrome.
Dravet syndrome is a severe, genetic developmental and epileptic brain disorder presented with severe, recurrent seizures, and significant cognitive and behavioural impairments.
The disease is difficult to treat, with a poor long-term prognosis, and has no approved disease-modifying therapies to date.
Zorevunersen has received Breakthrough Therapy Designation from the US Food and Drug Administration (FDA) based on positive clinical evidence from preliminary studies.
Data from Phase 1/2a and open-label extension (OLE) studies showed that patients treated with zorevunersen experienced significant and durable reductions in seizure frequency.
The drug also showed improvement in multiple cognition and behaviour measures, supporting a global registrational Phase 3 study with potential for disease modification.
Stoke recently announced its plans to begin Phase 3 EMPEROR study of zorevunersen, after alignment with regulatory agencies in the US, Europe, and Japan.
Stoke Therapeutics CEO Edward Kaye said: “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.”
