Europe’s drugs regulator said on Thursday it was reviewing data on COVID-19 antibody therapies developed by U.S. drugmakers Eli Lilly and Regeneron for use in some patients.

Two separate reviews of combination treatments by the drugmakers have been started based on trials in COVID-19 patients who do not need oxygen support and are at high risk of their condition worsening, the European Medicines Agency (EMA) said.

Eli Lilly’s combination therapy of two antibodies, bamlanivimab and etesevimab, helped cut the risk of hospitalization and death in COVID-19 patients by 70%, data from a late-stage trial showed in January.

Regeneron’s cocktail of casirivimab and imdevimab was authorised for emergency use in the United States in November, and was given to former U.S. President Donald Trump during his COVID-19 infection.

The four drugs are combinations of a class of medicines called monoclonal antibody treatments, or manufactured copies of antibodies created by the human body to fight infections.

The EMA also said it was studying the use of Lilly’s bamlanivimab as a singular therapy. The drug has already received emergency use approval in high-risk patients in the United States with mild to moderate COVID-19. (https://bit.ly/39NmGP0)

Any recommendations made by the EMA’s human medicine’s committee will have to be formally approved by the European Commission.