WASHINGTON – Regeneron's synthetic antibody treatment remains effective against the British and South African variants of the novel coronavirus, the US biotechnology company announced yesterday.
The therapy used on ex-president Donald Trump has had emergency approval since November for people with mild to moderate symptoms and a high risk of becoming seriously ill.
REGEN-COV – featuring potent neutralising antibodies called imdevimab and casirivimab – remained effective against both variants, the company said in a statement, although casirivimab's potency against the South African variant is "reduced".
Scientists from New York's Columbia University arrived at the same conclusion, and their study has been submitted for peer review.
The study's "pre-publication", however, presents more worrying results concerning another synthetic antibody, bamlanivimab: it is "inactive" against the South African variant, according to researchers.
This antibody is used in the treatment developed by pharmaceutical company Eli Lilly, which has also been approved for emergency use in the US.
Bamlanivimab will likely also be ineffective against the new Brazilian variant, since it presents mutations similar to the South African variant, scientists said.
Regeneron expects its antibody treatment will be effective against the Brazilian variant. Studies are under way to confirm this.
"These data show the continued ability of REGEN-COV to neutralise emerging strains, further validating our multi-antibody cocktail approach to infectious diseases," said George Yancopoulos, Regeneron's president and chief scientific officer.
"With two complementary antibodies in one therapeutic, even if one has reduced potency, the risk of the cocktail losing efficacy is significantly diminished.
"We have hundreds of additional potent, neutralising antibodies in our labs that could form new combinations that might be useful against future variants," he added.
Like all viruses, SARS-CoV-2, the coronavirus that causes Covid-19, mutates constantly as it reproduces.
But the mutation observed in the South African variant is particularly worrying to scientists due to its ability to bypass the remedies developed so far.
The US had confirmed 308 cases of the British variant as of January 26 and one case of the Brazilian variant, Rochelle Walensky, the new head of the US Centres for Disease Control and Prevention, said yesterday.
No cases of the South African variant have yet to be confirmed in the US. – AFP, January 28, 2021
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