FDA批准更高剂量的Evusheld用于新冠肺炎的暴露前预防

Introduction: The FDA approved increasing the dosage of Evusheld in specific groups for pre-exposure prophylaxis of COVID-19.

The U.S. Food and Drug Administration (FDA) has revised the Emergency Use Authorization (EUA) of Evusheld (a combination of tixagevimab and cilgavimab) to increase the initial dose for specific individuals (age ≧12 years, weight ≧40 kg) for pre-exposure prophylaxis of COVID-19.

Evusheld is a combination of two long-acting monoclonal antibodies designed to bind to different sites on the spike protein of the new coronavirus (SARS-CoV-2). Previously, the authorized dosage of Evusheld was tixagevimab 150mg + cilgavimab 150mg, respectively, for continuous intramuscular injection.

Under the revised EUA, the FDA approved an increase in the dosage of both tixagevimab and cilgavimab to 300 mg. The revision is based on recent information that previously approved doses of Evusheld may be less effective against certain Omicron subtypes. Available data suggest that higher doses of Evusheld are more likely to prevent infection by the Omicron subtypes BA.1 and BA.1.1.

For patients who have received previously approved doses (tixagevimab 150 mg and cilgavimab 150 mg), healthcare providers should contact them for additional doses of tixagevimab 150 mg and cilgavimab 150 mg as soon as possible. The new dose requires a larger volume per injection (3 mL instead of 1.5 mL), so injections should be made into muscles over large areas of the body to accommodate the dose (e.g. gluteal muscles).

Evusheld is suitable for individuals who are not currently infected with COVID-19 and have no known recent exposure to someone with COVID-19, and who:

Individuals with moderate to severe immune system compromise due to a medical condition or treatment with immunosuppressive medications who may not be able to mount an adequate immune response to a COVID-19 vaccine; or

Individuals with a history of serious adverse reactions (such as severe allergic reactions) to COVID-19 vaccines and/or COVID-19 vaccine components are not recommended to receive any available COVID-19 vaccine according to the approved or authorized schedule.

The effective protection period of Evusheld is currently unknown because the clinical trial data supporting the authorization were published before the BA.1 and BA1.1 subvariants emerged. Therefore, the FDA cannot provide recommendations regarding the timing of repeated dosing. In a press statement, the FDA noted that it will provide an update as more data become available.

Evusheld (Tixagevimab & Cilgavimab) is a long-acting neutralizing antibody (LAAB) combination therapy jointly developed by AstraZeneca and Vanderbilt University Medical Center. It consists of two neutralizing antibodies that bind different epitopes of the new coronavirus spike protein, namely tixagevimab and cilgavimab. AstraZeneca has optimized the antibodies to extend their half-life to three times that of ordinary monoclonal antibodies, with the goal of providing protection for up to 12 months after a single injection. In vitro study results indicate that Evusheld neutralizes other recently emerged SARS-CoV-2 virus variants, including Delta and Mu variants.

References:

https://www.empr.com/home/news/fda-authorizes-higher-dose-of-evusheld-for-preexposure-prophylaxis-of-covid-19/