Teva Pharmaceutical and Xenon Pharmaceutical announced that the FDA has granted Orphan Drug designation to the investigation drug XEN402 being developed for the treatment of pain associated with erythromelalgia (EM). XEN402 inhibits the SCN9A sodium channel.
EM is a rare autosomal dominant condition characterized by debilitating, spontaneous, or easily evoked attacks of symmetrical burning pain in the feet and hands, typically associated with elevated skin temperature and erythema. Symptoms are generally induced by exercise, prolonged standing, exposure to heat, and/or changes in humidity. The pain can be so severe that it can lead to suicide, and adequate treatment remains very challenging.