PF-00608404

PF-00608404 is a small molecule inhibitor of the voltage-gated sodium channel Nav1.7 (SCN9A), developed by Pfizer for the treatment of chronic pain conditions. Nav1.7 is highly expressed in peripheral sensory neurons and plays a critical role in the generation and conduction of pain signals; gain-of-function mutations in the SCN9A gene are associated with severe pain disorders like erythromelalgia. PF-00608404 was designed to be a selective blocker of this channel to provide analgesia while minimizing off-target effects on other sodium channel isoforms (such as Nav1.5 in the heart). The compound reached Phase 2 clinical development for indications including osteoarthritis pain and erythromelalgia, but development was ultimately discontinued by Pfizer.