Chenodeoxycholic acid (CDCA) is a naturally occurring bile acid that was approved in 1983 under the brand name Chenix for the treatment of people with radiolucent stones in the gallbladder. More recently, the US Food and Drug Administration (FDA) granted Chenodal (also CDCA) orphan drug designation for cerebrotendinous xanthomatosis (CTX). CTX is a rare progressive disorder that can affect the brain, spinal cord, tendons, eyes and arteries. Chenodal is not indicated for the treatment of CTX but has received a medical necessity determination in the US by the FDA. Travere Therapeutics is conducting a Phase 3 clinical trial to examine the safety and efficacy of Chenodal to treat CTX.
CTX is a bile acid synthesis disorder resulting in the deficiency of an enzyme necessary to convert cholesterol into the bile acid called chenodeoxycholic acid (CDCA). As a result the body is unable to break down cholesterol properly, causing toxins (e.g., cholestanol and bile alcohols) to build up over time. Affected individuals can experience neonatal cholestasis (jaundice or bile flow interruption), chronic diarrhea, the development of cataracts in both eyes before the age of 18, development of tendon xanthomas (fatty deposits in the tendons) during teenage years or later, and neurologic deterioration. There are no medications approved for the treatment of the disease.
Our investigational approach is to evaluate the use of Chenodal as a direct replacement therapy option for the restoration of physiologic bile acids and the regulation of cholestanol and bile alcohols compared to placebo.
In 2019, Travere Therapeutics initiated the RESTORE Study, a pivotal Phase 3 double-blind, placebo-controlled 24-week clinical trial to assess the safety and efficacy of Chenodal in patients with CTX. The primary efficacy endpoint of the RESTORE Study is the change from baseline in urine bile alcohols at the end of each double-blind treatment period. The study protocol allows for rescue measures to protect patient safety. The RESTORE study may support greater identification and earlier treatment efforts in this ultra-rare progressive neurological disorder.