FDA Approves Chenodiol for Treatment of Cerebrotendinous Xanthomatosis
Ctexli is the first FDA-approved treatment for adults with cerebrotendinous xanthomatosis.
The FDA announced approval of chenodiol (Ctexli) for the treatment of cerebrotendinous xanthomatosis (CTX), according to a news release.1 This is the first drug approved for the treatment of adults with CTX, which is a rare genetic metabolic disorder impacting lipid storage.
“The FDA is dedicated to supporting new drug development for rare diseases including very rare metabolic diseases like CTX,” said Janet Maynard, MD, MHS, director of the Office of Rare Diseases, Pediatrics, Urologic, and Reproductive Medicine with the FDA's Center for Drug Evaluation and Research. “CTX is a progressive multisystemic disorder that significantly impacts patients and previously lacked approved treatments.”
The approval of chenodiol was given to Mirum Pharmaceuticals for its Ctexli formula. | image credit: wladimir1804 / stock.adobe.com
According to the National Organization for Rare Disorders, roughly 1 in every 71000 to 148000 US patients have CTX.2 The disorder occurs when the CYP27A1 gene is mutated, causing an enzyme deficiency crucial to breaking down the body’s fats. CTX gives patients the inability to appropriately break down cholesterol, which results in the deposition of atypical metabolites in the brain, liver, skin, and tendons.
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Chenodiol “works to replace deficient levels of one of the bile acids, reducing the abnormal deposits of cholesterol metabolites thought to be responsible for clinical abnormalities in CTX,” continued authors of the release.1 Some common CTX symptoms include diarrhea, juvenile cataracts, fatty tumors, decline in cognitive function, and more.2
The approval of chenodiol was given to Mirum Pharmaceuticals’ Ctexli formula after its efficacy was tested in a double-blind, placebo controlled, randomized crossover withdrawal trial. Throughout its 24-week period, the trial exhibited chenodiol’s ability to reduce plasma cholestanol and urine 23S-pentol, which are specific cholesterol metabolites that increase in patients with CTX.1
Trial researchers recommended 250 mgs of chenodiol 3 times each day for proper treatment dosing. They also noted common side effects of the drug, including diarrhea, headache, abdominal pain, constipation, hypertension, muscular weakness, and upper respiratory tract infection.
“The prescribing information for Ctexli 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,” wrote the authors. “Patients should obtain liver blood tests before starting treatment, annually while on treatment and as clinically indicated. If signs of liver toxicity (eg, stomach pain, nausea, fatigue, dark urine, bruising, yellowing of the eyes and skin, itching) occur, patients are advised to see their doctor and discontinue Ctexli.”
The researchers then noted some drug interactions that patients prescribed chenodiol should consider before taking it. Chenodiol could lose its absorption effects if used with cholestyramine or colestipol, and hepatotoxicity can result from the combined use of chenodiol and coumarin.3
Finally, they explored patient populations most and least recommended to use the drug. Despite approval of the drug for adults with CTX, trials did include pediatric outcomes or results of its efficacy in patients 65 and older. There is no current data explaining that pregnant women taking chenodiol will result in an increased risk of major birth defects.
“Today's approval provides a safe and effective treatment option for CTX,” concluded Maynard.1
READ MORE: FDA Updates
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