Reduced Efficacy of Ronapreve (Casirivimab/Imdevimab) against Omicron Variant
The monoclonal antibodies casirivimab/imdevimab (Ronapreve), which work to neutralise SARS-CoV-2, can prevent severe cases of COVID-19 in patients infected with previous virus variants, including the Delta variant. However, in vitro neutralisation assays indicate reduced efficacy in the case of an infection with the Omicron variant.
The monoclonal antibodies casirivimab/imdevimab have been authorised under the product name Ronapreve as a therapeutic option for the treatment of COVID-19 since 12 November 2021. However, initial in vitro neutralisation assays show significantly reduced neutralisation activity against the Omicron variant of SARS-CoV-2, indicating thereby reduced efficacy.
The biomedicine maintains its neutralisation activity, and thus likely its efficacy, against all other virus variants of concern that are circulating at present (the Delta variant is still of particular concern at the moment). Therefore, the treating physician should take into account which virus variant the patient has been infected with.