Xenon Pharmaceuticals Inc., a clinical stage, neurology-focused biopharmaceutical company, today reported the expansion of its ion channel product pipeline with XEN496 (active ingredient ezogabine), a Kv7 potassium channel modulator for the potential treatment of epilepsy. Based on feedback from the U.S. Food and Drug Administration (FDA), Xenon anticipates initiating a single, pivotal Phase 3 clinical trial in approximately mid-2019 examining XEN496`s efficacy as a precision medicine treatment of KCNQ2 epileptic encephalopathy (KCNQ2-EE) or EIEE7, which is a rare, severe, pediatric epilepsy caused by loss-of-function missense mutations in the KCNQ2 gene that encodes for the Kv7.2 channel. Published case reports where physicians have used ezogabine in infants and young children with KCNQ2-EE suggest that XEN496 may be efficacious in this often hard-to-treat patient population.
Ezogabine, also known as retigabine, is the only anti-epileptic drug previously approved by the FDA with a mechanism of action that potentiates Kv7-mediated potassium current. Ezogabine was originally approved by the FDA in June 2011 as an adjunctive treatment for adults with focal seizures with or without secondary generalization. GlaxoSmithKline (GSK) marketed ezogabine in various jurisdictions – as Potiga in the U.S. and Trobalt in Europe – but withdrew the drug from the market worldwide in June 2017 citing commercial reasons.
Dr. Simon Pimstone, Xenon`s Chief Executive Officer, said, “We have done an immense amount of diligence leading up to the addition of XEN496 to our novel and robust pipeline of ion-channel, anti-epileptic drugs. Based on feedback from key opinion leaders, advocacy groups, pre-existing literature, and promising data generated to date, we believe there is tremendous support for us to vigorously pursue the development and commercialization of XEN496 in order to reach the pediatric KCNQ2-EE patient population as rapidly as possible.”