Tixagevimab/Cilgavimab: Monoclonal Antibodies in Coronavirus Disease 2019 (COVID-19)

Abstract

Monoclonal antibodies administration provides passive immunity against the virus that causes coronavirus disease 2019, allowing immediate antibody action without stimulating the body’s immune system. It is therefore an alternative for those who cannot be vaccinated, such as patients who are allergic to vaccines, or those who may have low immune response to the vaccine, such as organ transplant patients, cancer patients, and immunocompromised patients. This group of patients is at high risk of severe symptoms after being infected with the novel coronavirus 2019. These monoclonal antibodies act by binding to proteins on the surface spikes of viral particles, which are locations where mutations are common. At present, the main virus strains that account for more than 80% of the outbreak are Omicron subvariants BA.4 and BA.5, leading to the use of tixagevimab/cilgavimab, which is a combination of long-acting monoclonal antibodies effective against the novel coronavirus 2019 subvariants Omicron BA.4 and BA.5. The drug has been approved for emergency use for pre-exposure prophylaxis of coronavirus disease 2019 in the United States. When drug efficacy was evaluated at 6 months after drug administration, it was found to be able to prevent infection with the novel coronavirus 2019 better than in placebo group. However, further investigations on long-term adverse events are still needed.