Altimmune’s pemvidutide failed to significantly improve fibrosis in MASH patients in a Phase IIb study. The biotech crashed 53% in the aftermath of the readout.
Altimmune’s dual GLP-1/glucagon agonist pemvidutide helps resolve metabolic dysfunction-associated steatohepatitis—but does not appear to have significant therapeutic benefits on fibrosis associated with the condition, according to new data from a Phase IIb trial.
Writing to investors on Thursday, analysts at William Blair called this outcome “underwhelming.” Without demonstrating significant fibrosis improvement, they added, what makes pemvidutide different from other similar assets is “unclear.”
“While the Phase IIb IMPACT study met the MASH [metabolic dysfunction-associated steatohepatitis] resolution endpoint, we believe investors are considerably more interested in the other primary endpoint of fibrosis improvement,” which correlates with liver failure, death and progression to cirrhosis or hepatocellular carcinoma, according to the analysts.
Altimmune was trading at $3.61 at market close on Thursday, a 53% drop from its closing price the day prior.
Thursday’s readout represents 24-week data from the IMPACT trial, which enrolled more than 200 patients with biopsy-confirmed MASH and with stage F2 or F3 fibrosis. Pemvidutide was dosed at either 1.2-mg or 1.8-mg subcutaneous injections and controls were given placebo.
Results showed that 59.1% in the lower dose and 52.1% of patients in the higher dose pemvidutide arms achieved MASH resolution without worsening of fibrosis, compared with only 19.1% of placebo comparators.
In contrast, neither treatment arm saw statistically significant improvements in fibrosis without worsening MASH in comparison with the placebo group.
Altimmune also highlighted statistically significant weight loss with pemvidutide: Patients in the 1.2-mg and 1.8-mg dose groups lost 5% and 6.2% of their body weight at 24 weeks, respectively, whereas placebo counterparts only shed 1%. William Blair analysts, however, remained unimpressed, writing in their Thursday note that the magnitude of pemvidutide’s weight loss is “non-differentiating.”
“Given the similarity in development phase and dual agonism mechanism of action, we believe that Eli Lilly’s Mounjaro and Boehringer Ingelheim’s survoditude” are fair comparators—and both have shown better weight loss profiles, the analysts added.
Pemvidutide likewise met several other secondary endpoints, including reductions in liver fat and liver enzymes.
Despite the decidedly negative reaction from William Blair and investors, analysts at H.C. Wainwright remained optimistic. Thursday’s data, they wrote on Tuesday, “support advancement to Phase III and strengthen the case for pemvidutide as a potential best-in-class therapy.” The sell-off in Altimmune shares, they added, “is overdone.”
