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# Mirum’s Ctexli Approved for Rare Lipid Disease
- URL: https://www.fdaweb.com/mirums-ctexli-approved-for-rare-lipid-disease/
- Published: 2025-02-21T12:00:00.000Z
- Updated: 2026-09-14T14:53:41.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5158698

FDA has approved a Mirum Pharmaceuticals NDA for [Ctexli](https://www.accessdata.fda.gov/drugsatfda%5Fdocs/label/2025/219488s000lbl.pdf?ref=fdaweb.com) (chenodiol) for treating adults with cerebrotendinous xanthomatosis (CTX), a very rare lipid storage disease. The genetic metabolic disorder is caused by a mutation in a gene called CYP27A1, “resulting in a deficiency of the enzyme that is important in the body’s ability to break down fats,” an [agency release](https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-cerebrotendinous-xanthomatosis-rare-lipid-storage-disease?ref=fdaweb.com) says. “Due to reduced bile acid production in the liver, patients with CTX are unable to break down cholesterol in a normal way, resulting in deposition of atypical cholesterol metabolites (substances that result from the breakdown of cholesterol) in various places in the body including the brain, liver, skin and tendons, leading to damage to those organs and tissues.”

The agency says Ctexli works by replacing deficient levels of one of the bile acids, “reducing the abnormal deposits of cholesterol metabolites thought to be responsible for clinical abnormalities in CTX.” Its approval was based on clinical data showing the therapy led to a significant reduction in plasma cholestanol and urine 23S-pentol (cholesterol metabolites that are markedly increased in CTX patients) compared to placebo.

The prescribing information includes a warning for liver toxicity in all patients with increased risk for liver damage in patients with pre-existing liver disease or bile duct abnormalities, FDA’s notice says. “Patients should obtain liver blood tests before starting treatment, annually while on treatment and as clinically indicated,” it says.