The U.S. FDA has approved Mirum Pharmaceuticals’ Ctexli tablets for the treatment of adults with cerebrotendinous xanthomatosis (CTX), marking the first and only treatment approved for the rare, progressive and debilitating disease.
CTX, which results from a deficiency of a key enzyme in the bile acid synthesis pathway, is characterized by fatty yellow nodules located in the connective tissues within the brain. As the clinical course progresses, irreversible neurological deterioration leads to premature death.
Mirum’s approval is based on data from the phase 3 RESTORE study evaluating Ctexli in adult patients with CTX by measurement of urine bile alcohols and other secondary measures. The primary endpoint of reduction in bile alcohols was highly statistically significant, with a 20-fold difference between placebo and Ctexli treated patients in urine 23S-pentol levels.
Ctexli tablets are made of chenodiol, also known as chenodeoxycholic acid, a naturally occurring bile acid that was originally approved decades ago for the treatment of radiolucent stones in the gallbladder. Mirum acquired the drug from Travere Therapeutics in 2023, for an upfront payment of $210 million.