Xenon Pharmaceuticals Provides Updates on Partnered Neurology Pipeline Programs at the 2019 American Epilepsy Society (AES) Annual Meeting

Overview of Clinical Stage XEN901 and Related Patient Survey to be Presented in the “Genetic Epilepsies – Updates in the Science and Diagnosis” Exhibit in Room 318-319 on Sunday, December 8^th

Pre-Clinical Work Suggests Selective Sodium Channel Inhibitors that Reduce Action Potential Firing in Excitatory Neurons, While Sparing Inhibitory Interneurons, May Provide Promising Drug Profile

BURNABY, British Columbia, Dec. 07, 2019 (GLOBE NEWSWIRE) -- Xenon Pharmaceuticals Inc. (Nasdaq:XENE), a clinical stage biopharmaceutical company, announced today that it will provide updates on its partnered epilepsy programs at the American Epilepsy Society (AES) Annual Meeting held in Baltimore, MD.

Dr. Simon Pimstone, Xenon’s Chief Executive Officer, said, “There are a number of presentations at the AES meeting related to our recently announced license and collaboration with Neurocrine Biosciences. Our presentations provide details on the clinical stage XEN901 epilepsy program and other pre-clinical licensed Nav1.6 and dual Nav1.2/1.6 programs. In addition to the scientific poster sessions at AES, we will be presenting information on both our partnered and proprietary programs at the BioMarin scientific exhibit on Sunday.”

On December 2, 2019, Xenon announced a license and collaboration agreement with Neurocrine Biosciences, Inc. (Nasdaq:NBIX) to develop first-in-class treatments for epilepsy. Neurocrine Biosciences has an exclusive license to XEN901, a clinical stage selective Nav1.6 sodium channel inhibitor with potential in SCN8A developmental and epileptic encephalopathy (SCN8A-DEE) and other forms of epilepsy, including focal epilepsy. In addition, Neurocrine Biosciences gained an exclusive license to pre-clinical compounds for development, including selective Nav1.6 inhibitors and dual Nav1.2/1.6 inhibitors. The agreement also included a multi-year research collaboration to discover, identify and develop additional novel Nav1.6 and Nav1.2/1.6 inhibitors.

The presentations related to XEN901 and earlier stage selective Nav1.6 inhibitors and dual Nav1.2/1.6 inhibitor partnered programs at the AES meeting include:

• XEN901: A poster presentation entitled, “A Phase 1 Study in Healthy Subjects to Assess the Safety, Tolerability and Pharmacokinetics of XEN901, a Novel, Selective Nav1.6 Sodium Channel Inhibitor for the Treatment of SCN8A-Related Epilepsy” will be presented as Poster #15 in the BioMarin exhibit. A Phase 1 clinical trial was completed using a powder-in-capsule formulation of XEN901 in healthy adult subjects. Xenon developed a pediatric-specific, granule formulation of XEN901, and juvenile toxicology studies to support pediatric development activities have recently been completed. Neurocrine Biosciences anticipates filing an IND application with the FDA in the middle of 2020 in order to start a proposed clinical trial for XEN901 in SCN8A-DEE patients. Additionally, the results from an online survey of caregivers will be presented in Poster #18, entitled “An Online Survey of Caregivers of Patients with SCN8A Related Epilepsy.” The survey results help to improve the knowledge of disease course and phenotypic heterogeneity, as well as inform clinical trial design for later stages of development.