Feb. 24, 2025 – The FDA has approved a new pill for adults with cerebrotendinous xanthomatosis (CTX), a rare genetic disease that makes it hard for the body to handle cholesterol properly.
CTX is caused by a mutation in the CYP27A1 gene, leading to the lack of an enzyme needed for proper cholesterol breakdown. This reduces bile acid production, causing harmful cholesterol byproducts to build up and form fatty deposits (xanthomas) in the brain, liver, skin, and tendons. Over time, it can cause nerve damage, movement issues, jaundice, and increase the risk of heart and lung diseases.
The new pill, called Ctexli, contains chenodiol (chenodeoxycholic acid), a natural bile acid that helps restore the missing bile acid in patients with CTX. This reduces harmful cholesterol buildup, protects organs, and supports overall health. The FDA advises 250 mg tablets to be taken thrice a day. Ctexli is the first approved drug for the condition.
A 24-week clinical trial tested how well Ctexli worked in people with CTX ages 16 to 55 years. They received either 250 mg of Ctexli thrice a day or a placebo. Results showed that Ctexli significantly reduced harmful cholesterol breakdown products, which are usually high in patients with CTX, compared to the placebo. But it has not yet been established how safe and effective the drug is in children. The FDA has approved it for Mirum Pharmaceuticals.
The most common side effects include headaches, stomach pain, diarrhea, constipation, high blood pressure, muscle weakness, and upper airway infections.
Ctexli’s prescribing information warns that the medicine may cause liver problems, especially in people who already have liver disease or bile duct issues. They should get medical help right away if they have stomach pain, nausea, fatigue, dark urine, bruising, yellowing of the skin or eyes, or itching while using Ctexli. They must tell their doctors about all the prescription medicines (particularly antacids and blood thinners) and over-the-counter drugs, vitamins, and herbal and dietary supplements that they are taking before starting their treatment.
