The experimental antibody cocktail which U.S. President Donald Trump received when he tested positive for COVID-19 offers benefits against the novel coronavirus infection, according to a new study in animal models which provides more evidence of the clinical potential of the therapeutic.
While earlier studies had shown that the cocktail of two antibodies targeting the coronavirus spike protein could be used to neutralise the pathogen, scientists from the American biotechnology company Regeneron noted that further research in multiple animal models is needed to test the effectiveness of the formulation.
Mild and severe cases
In the current study, published in the journal Science, the researchers tested REGN-COV2 in rhesus macaques, which manifest mild COVID-19 symptoms, and in golden hamsters, which show symptoms that are much more severe, including rapid weight loss.
They found that when the cocktail was administered three days before challenging the macaques with the virus, the treatment almost completely blocked establishment of infection.
According to the scientists, this ability of REGN-COV2 “matches or exceeds the effects recently shown in vaccine efficacy studies using the same animal models.”
“These findings highlight the therapeutic potential of (this approach) to both protect from and treat SARS-CoV-2 disease,” the researchers noted in the study.
Macaques and hamsters
When the macaques were treated with the drug one day after infection, they said there was faster viral clearance than in controls who had not been treated with the cocktail.
In the hamster model, the study noted that the animals treated with the drug two days before infection exhibited a “dramatic protection from weight loss,” and decreased viral load in the lungs.
The scientists also reported benefits for hamsters treated one day after infection, as compared to controls. “In conclusion, our data provide evidence that REGN-COV2 based therapy may offer clinical benefit in both prevention and treatment settings of COVID-19 disease, where it is currently being evaluated,” they wrote in the study.