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.