In clinical trials, Ctexli was associated with reductions in plasma cholestanol and urine 23S-pentol levels, which are biomarkers linked to metabolic dysfunction in cerebrotendinous xanthomatosis.

The U.S. Food and Drug Administration (FDA) has approved Ctexli (chenodiol) for the treatment of cerebrotendinous xanthomatosis (CTX) in adults, marking the first approved therapy for this rare lipid storage disorder. CTX is an inherited metabolic disorder caused by mutations in the CYP27A1 gene, leading to a deficiency in an enzyme that is essential for fat metabolism. This enzymatic defect impairs bile acid synthesis, resulting in the accumulation of abnormal cholesterol metabolites—particularly cholestanol—in the brain, liver, skin, and tendons, which can cause multisystem dysfunction.

Ctexli functions by supplementing deficient bile acids to facilitate cholesterol metabolism and reduce pathological metabolite deposition. Its efficacy was established in a 24-week, double-blind, placebo-controlled, randomized crossover withdrawal trial. Patients receiving 250 mg of Ctexli three times daily demonstrated significant reductions in plasma cholestanol and urine 23S-pentol concentrations compared with placebo.

The prescribing information includes a liver toxicity warning, particularly for patients with pre-existing hepatic impairment or bile duct abnormalities. Liver function testing is recommended prior to initiating therapy, annually during treatment, and as clinically indicated. Clinicians should monitor for hepatotoxicity symptoms, including abdominal pain, fatigue, jaundice, dark urine, and pruritus. Discontinuation of therapy is advised if signs of liver dysfunction occur.

Common adverse events observed with Ctexli include diarrhea, headache, abdominal pain, constipation, hypertension, muscle weakness, and upper respiratory tract infection. The recommended dosing regimen is 250 mg orally three times daily.