Altimmune’s liver disease drug shows benefits in study, but investors remain unimpressed

By Padmanabhan Ananthan

Dec 19 (Reuters) – Altimmune said on Friday its experimental liver disease drug led to weight loss and improved markers for scarring and health of the organ based on non-invasive tests after 48 weeks of treatment in a mid-stage study, but the absence of biopsy-based data left investors disappointed.

The company was developing the drug, pemvidutide, to potentially treat metabolic dysfunction-associated steatohepatitis or MASH — a serious liver disease that develops when fat buildup causes inflammation of the organ.

Trial results at 24 weeks, released in June, showed the drug did not improve signs of liver scarring and was not significant enough when compared to placebo. On Friday, its shares slumped more than 20% to $3.92.

While non-invasive tests (NIT) suggest that antifibrotic activity persisted from week 24 to week 48, liver biopsies were not obtained at the second time point, and thus, existing data cannot meaningfully derisk pemvidutide prior to initiation of late-stage trial, said William Blair analyst Andy Hsieh.

“FDA’s stance remains that biopsy-based endpoints will be required for (accelerated) approval, and it is our view that NITs will unlikely supplant this requirement,” he said.

Altimmune said its drug showed significant reductions in key non-invasive measures of liver health and inflammation, including liver fat content.

The company plans to start a late-stage trial next year for pemvidutide, which 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, and is being studied separately as an obesity treatment.

It said patients on the higher dose of 1.8mg lost an average of 7.5% of their body weight at 48 weeks, with no evidence of plateauing, compared with 0.2% in placebo.

Altimmune said in a conference call the 2.4mg dose would be incorporated in the late-stage trial.

Madrigal Pharmaceuticals’ Rezdiffra is approved for MASH, alongside Novo’s Wegovy.

(Reporting by Padmanabhan Ananthan in Bengaluru; Editing by Shilpi Majumdar)