Altimmune Shares Slump as Weight-loss Drug’s Fatty Liver Trial Data Disappoints

(Reuters) -Altimmune shares cratered more than 50% on Thursday after its experimental obesity drug did not significantly improve liver scarring in patients with fatty liver disease in a mid-stage trial.

Many of the popular newer diabetes and weight-loss drugs are being tested to treat several additional health conditions such as liver diseases, chronic kidney disease and neurological disorders.

Improvement in fibrosis, or scarring, induced by Altimmune’s drug, pemvidutide, was not significant enough when compared with placebo. But the experimental drug did show a subsiding of metabolic dysfunction-associated steatohepatitis (MASH) without a worsening of liver scarring in up to 59.1% of participants in the 212-patient trial.

The company’s medical chief Scott Harris was upbeat on a conference call with analysts, saying the MASH subsiding alone would be sufficient for securing approval, based on U.S. Food and Drug Administration (FDA) guidance.

Harris said “statistical significance could potentially have been achieved at week 48.” Mazen Noureddin, principal investigator of the trial, added that a higher dose could also show further fibrosis improvements and weight loss.

The company will continue the trial for a total of 48 weeks, with the final data readout expected by the end of the year.

The overall 24-week data looks quite good, but missing on statistical significance for fibrosis improvement will be hard for investors to look past, said Jonathan Wolleben of Citizens Capital Markets and Advisory.

Shares were down 52.1% at $3.68, with some analysts viewing the sell-off as “overdone”.

The company has a late-stage ready drug “with one of the most attractive anti-MASH clinical profiles,” B.Riley analyst Mayank Mamtani said.

Madrigal Pharmaceuticals’ Rezdiffra is the only U.S.-approved drug for MASH.

Pemvidutide belongs to the same class of drugs as Novo Nordisk’s Wegovy and Ozempic and Eli Lilly’s Mounjaro and Zepbound, known as GLP-1 agonists. It is being studied separately as an obesity treatment.

(Reporting by Puyaan Singh in Bengaluru; Editing by Devika Syamnath and Leroy Leo)