The U.S. government said this week it is halting distribution of Eli Lilly & Co.’s COVID-19 antibody treatment in six states due to the growing prevalence of the P.1 and B.1.351 variants there. Lilly’s combination therapy of bamlanivimab and etesevimab “are not active against either the P.1 or B.1.351 variants,” which were first identified in Brazil and South Africa, respectively, the Assistant Secretary for Preparedness and Response said Wednesday. Coronavirus cases associated with these variants now make up more than 10% of all cases in Arizona, California, Florida, Illinois, Indiana, Massachussetts, Oregon, and Washington. Instead, the agency recommends using Regeneron Pharmaceuticals Inc.’s antibody treatment. This is not the first time there has been concern about bamlanivimab’s effectiveness. The Food and Drug Administration in April pulled the emergency authorization for bamlanivimab as a standalone treatment over concerns about its effectiveness against variants. There are three authorized antibody cocktails in the U.S., developed by Lilly, Regeneron, and Vir Biotechnology Inc. /GlaxoSmithKline . The Vir and GSK therapy was authorized earlier this week.

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