Tixagevimab-cilgavimab (Evusheld) lost authorization for use in the U.S. to prevent COVID-19 until further notice, the FDA 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 , 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 mount 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.
In light of the news, the CDC on Friday for people with immunocompromising conditions and those living with them, including that they receive the latest bivalent COVID-19 booster if they have not already, wear a well-fitting high-quality mask in public, maintain distance in crowded areas, and improve indoor ventilation.
The CDC also recommended that people identify where testing locations are before getting sick, and to test if exposed.
If patients do develop COVID-19, the FDA and CDC 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, it is 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.
This story was updated on January 27 to include recommendations from the CDC for people with immunocompromising conditions.