Estimated prevalence

  • 50,000 patients in US. NaV1.7 Identified mutation estimated to affect at least 5,000 patients

Erythromelalgia (EM) is a rare neuromuscular condition with no currently approved treatments.

EM commonly affects the feet, but may occur in the hands, face, or other parts of the body. It emerges during childhood but can also present in adulthood. EM flares are usually triggered by warmth, physical activity or stress. Many people can not tolerate any exercise, baths or showers, and some are unable to wear socks. In severe cases, the disease may lead to depression, anxiety and suicidal tendencies.


  • Erythema, heat
  • Pain – Usually severe burning pain but may include pins and needles or itching
  • Swelling (not always present)
  • Change in perspiration (not always present)
  • Purple discoloration (not always present)

Types of EM

  • Primary EM: Inherited or Sporadic SCN9A mutations + non genetic or uncharacterized
  • Secondary EM: Related to an underlying disease, toxin or drug induced


  • There are no currently approved treatments, and off-label treatments often ineffective

CC8464 is potent (nM) and state-dependent inhibitor of the human NaV1.7 with high target selectivity and a favorable profile:

  • CC8464 may preferentially affect injured or inflamed tissues while having minimal effect on the NaV1.7 channels in uninjured/healthy tissues

  • Orally bioavailable

  • Peripherally restricted, no distribution to the central nervous system (CNS)

  • No measured or observed CNS and muscle/motor dysfunction effects
  • No anticipated effect on normal pain sensation

  • Effective in multiple animal models of pain in animals