Several synthetic antibody treatments against Covid-19 are no longer effective against the Omicron variant.
This is particularly the case of that of the Regeneron and Roche laboratories, used in France, indicates this Friday the research agency ANRS / Emerging infectious diseases.
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The preliminary results of preclinical trials on the effectiveness of monoclonal antibodies against the Omicron variant showed that Ronapreve (developed by Regeneron with the Roche laboratory) no longer has "significant activity against the Omicron variant", specifies the ANRS.
This medicine combines two synthetic antibodies, called "monoclonal", casirivimab and imdevimab.
It is given as a single intravenous injection.
Synthetic antibodies are recommended by the WHO (World Health Organization) for elderly patients or patients with a weakened immune system.
Two products used in France are still effective
The tests also show that the Regdanvimab monotherapy from the Celltrion laboratory and the Bamlanivimab / Etesevimab dual antibody therapy from the Lilly laboratory "no longer have significant activity against the Omicron variant".
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On the other hand, two products with authorizations for use in France retain a neutralizing activity against the new variant, underlines the ANRS.
It is first of all the monotherapy Xevudy (Sotrovimab antibody) developed by the GSK Vir Biotechnology laboratories, "whose decrease in activity is moderate".
This antibody is offered for the early treatment of infected patients with risk factors for developing a severe form of Covid-19.
This is also the Evusheld therapeutic cocktail from the AstraZeneca laboratory (combination of the Tixagevimab and Cilgavimab antibodies) which “retains significant neutralizing activity despite a greater drop in activity”.
This cocktail is proposed for the prevention of severe forms in immunocompromised patients.