Neurocrine Biosciences has signed a licence and collaboration agreement valued at more than $1.7bn with Xenon Pharmaceuticals to develop epilepsy treatments.
As part of the deal, Neurocrine receives an exclusive licence to a selective Nav1.6 sodium channel inhibitor candidate, XEN901. The drug is being developed to potentially treat SCN8A developmental and epileptic encephalopathy (SCN8A-DEE) and other epilepsies.
Neurocrine also gets a licence to exclusively develop pre-clinical compounds, including selective Nav1.6 and dual Nav1.2 / 1.6 inhibitors.
Furthermore, the agreement includes a multi-year research alliance to discover and develop additional Nav1.6 and Nav1.2 / 1.6 inhibitors.
Neurocrine Biosciences CEO Kevin Gorman said: “The agreement with Xenon strengthens Neurocrine Biosciences’ diverse and growing pipeline and reinforces our long-term commitment of becoming a leading neuroscience-focused biopharmaceutical company.”
Neurocrine will bear developments costs of all programmes covered under the partnership. The company will pay $50m to Xenon, including an upfront cash payment of $30m and an equity investment of $20m.

US Tariffs are shifting - will you react or anticipate?
Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.
By GlobalDataFurthermore, Neurocrine will pay up to $25m upon the US Food and Drug Administration (FDA) acceptance of XEN901’s investigational new drug (IND) application. Of this payment, 55% will be paid as an equity investment.
The company expects to file an IND next year for the clinical trial of XEN901 in SCN8A-DEE patients.
Xenon will also gain up to $1.7bn in development, regulatory and commercial milestones associated with XEN901 and additional licenced Nav1.6 or Nav1.2 / 1.6 inhibitors, as well as sales royalties.
The company holds an option to fund 50% of the US development costs of a product candidate and will, in turn, receive royalties for XEN901 sales in the country.
Xenon Pharmaceuticals CEO Dr Simon Pimstone said: “Importantly, this collaboration represents a significant investment in XEN901 and Xenon’s earlier-stage Nav1.6 and Nav1.2 / 1.6 inhibitor programs and allows for a broader development of these promising compounds than we could accomplish independently.
“Furthermore, the additional capital from this transaction will support our efforts to advance and expand our proprietary pipeline.”