FDA Approves Mirum’s CTEXLI™ (Chenodiol) Tablets for Treating Cerebrotendinous Xanthomatosis (CTX)
Tuesday, February 25, 2025
Mirum Pharmaceuticals, Inc. has received approval from the U.S. Food and Drug Administration (FDA) for CTEXLI™ (chenodiol) tablets, a bile acid treatment for adults with cerebrotendinous xanthomatosis (CTX). CTEXLI is the first and only approved treatment for this rare and progressive condition.
The approval is based on results from the Phase 3 RESTORE study, which assessed the safety and effectiveness of CTEXLI in adults with CTX by measuring urine bile alcohol levels and other secondary indicators. The primary goal of reducing bile alcohols (urine 23S-pentol) showed a highly significant statistical outcome (p<0.0001). At the end of the study’s randomised double-blind withdrawal phase, patients treated with CTEXLI had urine 23S-pentol levels 20 times lower than those given a placebo.
CTX results from a deficiency of the bile acid chenodeoxycholic acid (CDCA), leading to an accumulation of bile alcohols and toxic levels of cholestanol. Cholestanol is the main factor driving symptoms and disease progression, including irreversible neurological damage. Findings from the RESTORE study showed that treatment with CTEXLI not only improved urine bile alcohol levels but also reduced serum cholestanol levels. A higher number of patients receiving a placebo required blinded rescue therapy, further confirming the treatment's effectiveness.
CTX is a rare genetic disorder caused by an enzyme deficiency in the bile acid synthesis process. It leads to fatty yellow deposits (xanthomas) in the connective tissues of the brain, causing progressive damage. As the condition advances, it results in severe neurological decline and can lead to premature death. CTX is estimated to affect between one and two thousand people in the United States.
CTEXLI, also known as chenodiol, is a form of chenodeoxycholic acid (CDCA), a naturally occurring bile acid initially approved for treating gallbladder stones. It was evaluated in the Phase 3 RESTORE study, the first and only clinical trial for CTX. This disease affects various parts of the body, including the brain, spinal cord, tendons, eyes, and arteries.
Source: mirumpharma.com
