Casirivimab/imdevimab

Casirivimab/imdevimab, sold under the brand name REGEN‑COV among others, is a combination medicine used for the treatment and prevention of COVID‑19. It consists of two human monoclonal antibodies, casirivimab and imdevimab that must be mixed together and administered as an infusion or subcutaneous injection. The combination of two antibodies is intended to prevent mutational escape. It is also available as a co-formulated product. It was developed by the American biotechnology company Regeneron Pharmaceuticals.

The most common side effects include allergic reactions, which include infusion related reactions, injection site reactions, brief pain, weakness and others.

The combination is approved under the brand name Ronapreve for medical use in Japan, the United Kingdom, the European Union, and Australia.

In January 2022, the U.S. Food and Drug Administration (FDA) revised the authorizations for two monoclonal antibody treatments – bamlanivimab/etesevimab (administered together) and casirivimab/imdevimab – to limit their use to only when the recipients are likely to have been infected with or exposed to a variant that is susceptible to these treatments because data show these treatments are highly unlikely to be active against the omicron variant.