Tixagevimab-cilgavimab (Evusheld) lost authorization for use in the U.S. to prevent COVID-19 until further notice, the FDA announced on Thursday.
The agency revised the monoclonal antibody cocktail’s emergency use authorization (EUA) to limit its use to only periods when SARS-CoV-2 variants susceptible to it account for at least 9% of COVID-19 cases nationally.
“Data show Evusheld is unlikely to be active against certain SARS-CoV-2 variants,” the FDA wrote in its announcement. “According to the most recent CDC Nowcast data, these variants are projected to be responsible for more than 90% of current infections in the U.S. This means that Evusheld is not expected to provide protection against developing COVID-19 if exposed to those variants.”
According to the current Nowcast estimates, XBB.1.5 is responsible for 49% of cases in the U.S., BA.1.1 for 27%, and BQ.1 for 13% — all three resistant to tixagevimab-cilgavimab.
The monoclonal antibody had been authorized for use as pre-exposure prophylaxis of COVID-19 in immunocompromised people ages 12 years and up who are not expected to an adequate response to vaccination as well as those with a history of severe adverse reaction to COVID-19 vaccination or allergies to certain components in the vaccines.
If patients do develop COVID-19, the agency recommended other authorized options for early treatment as appropriate, including nirmatrelvir-ritonavir (Paxlovid), remdesivir (Veklury), or molnupiravir (Lagevrio). These agents are still expected to retain effectiveness against the currently circulating variants and are all indicated for patients with mild-to-moderate cases but who are at high risk for severe outcomes, including hospitalization or death.
Of note, the government recommended that facilities and providers hold on to their supply of tixagevimab-cilgavimab, the FDA said, “in the event that SARS-CoV-2 variants which are neutralized by Evusheld become more prevalent in the U.S. in the future.”
The agency said it would continue to work with other agencies — including the CDC and NIH — to follow how variants affect currently authorized therapies.