Positive results announced in phase 3 study of cerebrotendinous xanthomatosis drug

A Bay Area pharmaceutical firm has announced positive data from a phase 3 clinical trial evaluating Chenodal tablets to treat adults with cerebrotendinous xanthomatosis, an autosomal, recessive, progressive genetic disorder.

According to a release from Mirum Pharmaceuticals Inc., the randomized, withdrawal, placebo-controlled study, called RESTORE, evaluated the safety and efficacy of Chenodal (chenodiol) by measuring the level of urine bile alcohols.

Study protocol involved a 4-week screening period, a treatment period of 6 months and a follow-up phone call 30 days after administration of final dose. The four treatment periods consisted of an 8-week open-label chenodiol period, a 4-week randomized withdrawal period (placebo or chenodiol), a second 8-week open-label chenodiol period for all patients, and a second 4-week randomized withdrawal period.

Per the company, the study met its primary endpoint of reduction in bile alcohols (urine 23S-pentol) in a statistically significant manner, with a 20-fold difference between active chenodiol and placebo at the end of the randomized double-blind withdrawal.

Further, data showed treatment with chenodiol not only improved urine bile alcohols but also improved serum cholestanol. Additionally, per the release, a greater proportion of participants given placebo required blinded rescue therapy, demonstrating the robustness of the effect.

“This is an extraordinary outcome, and we look forward to moving quickly to submit these data to the FDA with the goal of broadening the impact of Chenodal for patients with [cerebrotendinous xanthomatosis],” Chris Peetz, president and CEO at Mirum, stated in the release. “We are grateful to the patients and health care providers who made these results possible, and to the Travere team for their dedicated work leading this landmark study.”

Mirum expects to submit a new drug application to the FDA during the first half of 2024.