Altimmune obesity drug well-positioned despite safety data
Published: Mar 22, 2023
By Ana Mulero
Altimmune released mid-stage data Tuesday showing its obesity drug, pemvidutide, helped reduce patients’ weight by 10%, but the company’s shares tumbled 55% shortly after due, likely due to safety concerns.
Pemvidutide is an investigational, peptide-based GLP-1/glucagon dual receptor agonist in development to treat obesity and non-alcoholic steatohepatitis (NASH).
The new data draws from 160 patients with obesity in a Phase II trial and 54 patients with obesity and type 2 diabetes in a Phase Ib safety trial.
At week 24, approximately 50% of patients shed 10% of their weight, and approximately 20% reduced their weight by 15%.
The Phase II safety data is where Altimmune encountered challenges. In the pemvidutide cohort, 24% discontinued treatment. About half of these withdrew due to gastrointestinal (GI) adverse events, which Altimmune reported occurred mostly within the first 16 weeks.
One patient receiving the 2.4mg dose experienced nausea and vomiting and required rehydration. Although the side effects were mostly dose-related, the study protocol did not allow for dose reduction due to intolerability, according to the press release.
Altimmune likened the frequency of adverse events to those seen in prior trials of pemvidutide.
Discontinuation due to adverse events could be mitigated with lower doses of pemvidutide, Scott Harris, chief medical officer, Altimmune, said in a conference call on Tuesday.
Market reaction was swift and severe, as Altimmune shares dipped by 55% to $4.95 from Monday’s closing of $10.92.
Mayank Mamtani, managing director and group head of healthcare research at B. Riley Securities, told BioSpace that “biotech can get a little extreme in terms of market reactions.”
He added that Altimmune was overly confident in designing the study in a way that it would not be able to lower the dose in the case of side effects, but he said the company should be able to find an optimal dosing regimen.
Pemvidutide could be a competitor to Novo Nordisk’s Wegovy and Eli Lilly’s Mounjaro (tirzepatide), which is awaiting approval in this indication, in the potentially multi-billion-dollar obesity market.
GI issues have also been reported with both Wegovy and tirzepatide.
When the FDA approved Wegovy in January 2021, it was the first new drug for chronic weight management since 2014. Lilly’s Mounjaro received FDA approval for type 2 diabetes in May 2022.
Mamtani said the issue with both Wegovy and Mounjaro is that they need to be prescribed by a specialist due to the associated titration.
He said Altimmune could face a challenge in funding another mid-stage study to address the safety concerns. Still, he said, pemvidutide could be uniquely positioned in the market as data show it does not cause hypoglycemia while also addressing NASH.