Regeneron's synthetic antibody treatment remains effective against the British and South African variants, the US biotechnology company announced on Wednesday (January 27th).
The cocktail of antibodies, which had been used to treat former President Donald Trump, has been urgently authorized by the US Medicines Agency since the end of November, for people who have developed mild or moderate symptoms of Covid-19 and at high risk of developing a severe form of the disease.
Read also: Covid-19: Regeneron, treatment taken by Donald Trump, is approved in the United States
REGEN-COV, made up of
"the two neutralizing antibodies"
called imdevimab and casirivimab,
"retained its potent neutralizing capacity against the
British
B.1.1.7 variant"
as well as
"against the
South African
B.1.351 variant"
, has the company said in a statement.
For the South African variant, however, one of the two antibodies, casirivimab, had its
"potency reduced"
.
Scientists at Columbia University came to the same conclusions, and their study was submitted for peer review.
This
“pre-publication”, however,
presents more worrying results concerning other synthetic antibodies, bamlanivimab: it is
“inactive”
against the South African variant, according to the researchers.
However, this is what is used in the treatment of the company Eli Lilly, which also benefits from an emergency authorization in the United States.
Bamlanivimab should also be ineffective against the Brazilian variant, since the latter has mutations similar to South Africa, the scientists say.
Read also: United States: a gorilla treated with antibodies recovered from Covid-19
Regeneron also expects its treatment to remain equally effective against the Brazilian variant, and studies are underway to confirm this.
"These data
(...)
validate our approach consisting of a cocktail of several antibodies,"
said George Yancopoulos, President and Chief Scientific Officer of Regeneron.
"With two complementary antibodies in a treatment, even if one sees its potency reduced, the risk of the cocktail losing its effectiveness is significantly reduced."
“We have hundreds of powerful neutralizing antibodies in our labs that could form new combinations that may be useful against future variants,”
he added.
Variants are different versions of the original coronavirus, which appear over time due to various mutations.
A normal phenomenon in the life of a virus.
But the mutation observed in the variant that emerged in South Africa worries scientists particularly about its ability to bypass the remedies developed.
In the United States, 308 cases of the British variant have been confirmed as of January 26, and one case of the Brazilian variant, said Rochelle Walensky, the future director of the Centers for Disease Control, the country's main federal public health agency, on Wednesday.
No case of the South African variant has yet been confirmed in the United States.