Madrigal Pharmaceuticals has secured accelerated approval from the US Food and Drug Administration (FDA) for Rezdiffra (resmetirom) to treat patients with liver scarring due to fatty liver disease.

The FDA has authorised the use of Rezdiffra with diet and exercise to treat adults with noncirrhotic nonalcoholic steatohepatitis (NASH) with moderate to advanced liver fibrosis.

Rezdiffra is an oral, once-daily THR-β agonist. It is designed to target the underlying causes of NASH.

The indication’s continued approval could be subject to confirmation and a description of its therapeutic benefit through ongoing confirmatory trials.

The accelerated approval was based on the findings of the ongoing, multicentre, randomised, double-blind, placebo-controlled Phase 3 MAESTRO-NASH trial.

It recruited 1,759 patients with biopsy-confirmed NASH who were randomised in a 1:1:1 ratio for 52 weeks of treatment with 100mg and 80mg doses of Rezdiffra or placebo.

When compared to placebo, Rezdiffra showed statistically significant improvement on two primary endpoints of NASH resolution and improvement in fibrosis.

The drug candidate showed improvement in fibrosis by at least one stage without worsening the NAFLD activity score and resolution of NASH.

Reduction of NASH and reduction of fibrosis were independent of age, gender, presence of type 2 diabetes, and fibrosis stage.

Madrigal Pharmaceuticals CEO Bill Sibold said: “NASH with moderate to advanced liver fibrosis is a serious and progressive liver disease that, until now, has not had an FDA-approved therapy.

“The accelerated approval of Rezdiffra is a culmination of more than 15 years of research from our founder Dr. Becky Taub and a small R&D team that took on one of the biggest challenges in drug development.

“This is a historic moment for the NASH field and represents the best of what our industry is capable of. We’re excited to deliver Rezdiffra to patients in need.”

As an outcomes study, MAESTRO-NASH is still being conducted to produce confirmatory data. If found positive, it will support complete approval and help confirm clinical benefit.

Patients with well-compensated NASH cirrhosis receiving Rezdiffra treatment as opposed to placebo are being compared in a second ongoing outcomes trial to see if they advance to liver decompensation events.