The U.S. Food and Drug Administration (FDA) has revised the emergency use authorization (EUA) for AstraZeneca's Evusheld (tixagevimab co-packaged with cilgavimab), limiting its use for pre-exposure prophylaxis of COVID-19 in the United States. This decision, announced on January 26, 2023, is based on the sustained high frequency of circulating SARS-CoV-2 variants against which Evusheld demonstrates reduced in vitro neutralization. Specifically, Evusheld does not neutralize Omicron subvariants BQ.1, BQ.1.1, BF.7, BF.11, BA.5.2.6, BA.4.6, BA.2.75.2, XBB and XBB.1.5, which collectively account for over 90% of COVID-19 cases in the US, according to CDC data.
The FDA has indicated to AstraZeneca that it may reinstate Evusheld’s authorization if the national prevalence of resistant Omicron subvariants reduces to 90% or less sustainably. The US government recommends all Evusheld product be retained and properly stored in the event that variants susceptible to Evusheld, including those currently circulating at lower prevalence, become more prevalent in the future.
Impact on Immunocompromised Individuals
Evusheld had been authorized for pre-exposure prophylaxis in adults and pediatric individuals (12 years of age and older weighing at least 40 kg) who are not currently infected with SARS-CoV-2 and who have moderate to severe immune compromise due to a medical condition or receipt of immunosuppressive medications or treatments and may not mount an adequate immune response to COVID-19 vaccination or for whom vaccination with any available COVID-19 vaccine is not recommended due to a history of severe adverse reaction to a COVID-19 vaccine(s) and/or COVID-19 vaccine component(s).
With the current prevalence of resistant variants, the FDA has determined that the risks of potential side effects, including allergic reactions, outweigh the benefits of using Evusheld. The agency has revised Evusheld's emergency use authorization (EUA) to state that it is now only authorized for use if more than 10% of circulating variants are expected to be neutralized by it.
AstraZeneca's Response and Future Plans
AstraZeneca is actively working with the FDA and other health authorities to continuously assess and share data regarding Evusheld and emerging SARS-CoV-2 variants. The company has also initiated the SUPERNOVA Phase I/III trial to evaluate a next-generation long-acting antibody (LAAB) for COVID-19 pre-exposure prophylaxis in immunocompromised individuals. In in vitro lab studies, the new LAAB has been shown to neutralize all SARS-CoV-2 variants tested to date, including variants that have proved resistant to other monoclonal antibodies. AstraZeneca aims to make the new LAAB available in the second half of 2023, pending trial results and regulatory reviews.
Continued Recommendations for Prevention
The CDC continues to recommend that immunocompromised individuals prioritize other prevention measures, including masking, receiving the bivalent COVID-19 booster vaccination, and knowing where and how to get tested and access antiviral medication if exposed to the virus.
