Imagine pain in an arm or leg so intense that the sufferer would rather undergo an amputation than put up with it any longer. For those with complex regional pain syndrome (CRPS), this is not just a hypothetical nightmare—it is reality. According to the National Institute of Neurological Disorders and Stroke (NINDS), CRPS is a chronic condition most often affecting one limb (arm, leg, hand or foot), usually after an injury or trauma to that limb. The main complaint is pain that is way out of proportion to the severity of the initial injury. The cause of the condition isn’t clearly understood, according to NINDS. It can manifest as visual swelling, redness and other abnormalities in a limb.
CRPS is widely considered to be the single worst source of pain—ranking higher on pain scales than childbirth, cancer and amputation. Yet the condition is rare and can be difficult to recognize. As a result, patients with CRPS—predominantly women, with an average age of 40, according to the National Institutes of Health—can search for an average of approximately four years before being properly diagnosed with the condition, according to a study published in the Scandinavian Journal of Pain. This long wait, compounded by the pain, can severely impact their daily living and quality of life. Although reports of those experiencing the symptoms of this condition have existed as long ago as the Civil War, according to a study published in The BMJ, no medication has yet been approved.
Randall Kaye, M.D. is the Chief Medical Officer at Axsome Therapeutics, Inc., a clinical-stage biopharmaceutical company currently enrolling patients at sites across the U.S., Canada, the U.K. and Australia in a clinical study, called CREATE-1, to evaluate its experimental medication AXS-02 for the treatment of chronic pain caused by CRPS. In this quest, Axsome is motivated by the many stories from CRPS patients, describing how difficult it can be to live with CRPS. Thought not yet approved, AXS-02 has been granted Fast Track and Orphan Drug Designation by the U.S. Food and Drug Administration and Orphan Medicinal Product Designation.
AXS-02 (disodium zoledronate tetrahydrate) is an oral, non-opioid, potentially first-in-class pain therapeutic being developed for the treatment of chronic pain caused by CRPS. The compound has multiple mechanisms of action to address chronic pain: it inhibits bone-resorbing osteoclasts, downregulates acid-sensing ion channels, reduces pro-inflammatory cytokine production and is anti-angiogenic.
As a result of his efforts at Axsome Therapeutics, Dr. Kaye is especially able to appreciate the need for novel approaches to CRPS and to oversee efforts to advance the state of care.
National Institute of Neurological Disorders and Stroke