The US Food and Drug Administration (FDA) has granted approval for Rezdiffra (resmetirom) for the treatment of adults with noncirrhotic non-alcoholic steatohepatitis (NASH) with moderate to advanced liver scarring (fibrosis), to be used in conjunction with diet and exercise.

Dr. Nikolay Nikolov, Acting Director of the Office of Immunology and Inflammation in the FDA's Center for Drug Evaluation and Research, emphasized the significance of this approval, stating, "Today's approval of Rezdiffra will, for the first time, provide a treatment option for these patients, in addition to diet and exercise."

NASH, a consequence of nonalcoholic fatty liver disease, can lead to liver inflammation and scarring over time, resulting in liver dysfunction. It is often associated with other health issues such as high blood pressure and type 2 diabetes. Rezdiffra, a partial activator of a thyroid hormone receptor, reduces liver fat accumulation by activating this receptor in the liver.

The safety and efficacy of Rezdiffra were evaluated based on an analysis of a surrogate endpoint at month 12 in a 54-month, randomized, double-blind placebo-controlled trial. The trial demonstrated that a greater proportion of subjects treated with Rezdiffra experienced NASH resolution or an improvement in liver scarring compared to those who received placebo.

Common side effects of Rezdiffra include diarrhea and nausea. Certain warnings and precautions accompany its use, including drug-induced liver toxicity and gallbladder-related side effects. Rezdiffra should be avoided in patients with decompensated cirrhosis, and treatment should be discontinued if signs of worsening liver function occur.

Rezdiffra received approval under the accelerated approval pathway, with ongoing assessment of clinical benefit in a 54-month study. It also received Breakthrough Therapy, Fast Track, and Priority Review designations for this indication.