ETF warns that monoclonal antibodies may not be effective against emerging strains of SARS-CoV-2

EMA’s Emergency Task Force (ETF) has cautioned that monoclonal antibodies currently authorised for COVID-19 are unlikely to be effective against emerging strains of SARS-CoV-2.

These monoclonal antibodies are designed to neutralise the virus by binding to the spike protein on its surface. However, emerging strains have mutations in this protein which can reduce the ability of the antibodies to bind to them.

Recent laboratory studies show that monoclonal antibodies targeting the spike protein are poorly effective at neutralising Omicron strains BA.4.6, BA.2.75.2 and XBB. The data also show that these monoclonal antibodies do not significantly neutralise BQ.1 and BQ.1.1, which are expected to become the dominant strains in the EU in the coming weeks.

Although it is not yet known to what extent the reduced neutralising activity translates into reduced benefits for patients, healthcare professionals will need to consider alternative treatments, especially if subvariants such as BQ.1 and BQ.1.1 become prevalent.

Antiviral treatments such as Paxlovid (nirmatrelvir / ritonavir) and Veklury (remdesivir), which have different mechanisms of action, are expected to retain their activity against the emerging strains. These treatments are approved in the EU for patients with COVID-19 who do not require supplemental oxygen and are at increased risk of their disease progressing to severe COVID-19.

The ETF therefore encourages EU Member States to ensure that healthcare professionals have access to these antiviral treatments for patients at increased risk of severe COVID-19.

The ETF, along with the European Centre for Disease Control and Prevention (ECDC), will continue to monitor the epidemiological situation in the EU. The ETF will also consider recommending an update to the product information for individual monoclonal antibodies.

More about the medicines

A monoclonal antibody is an antibody (a type of protein) that has been designed to recognise and attach to a specific structure (called an antigen).

Four authorised monoclonal antibodies attach to the spike protein of SARS-CoV-2 and by doing so prevent the virus from being able to enter the body’s cells. These are Evusheld (tixagevimab / cilgavimab), Regkirona (regdanvimab), Ronapreve (casirivimab / imdevimab) and Xevudy (sotrovimab). EMA has issued advice on the use of a fifth product (bamlanivimab / etesevimab) under Article 5(3) of Regulation 726/2004.

These monoclonal antibodies are used for treating COVID-19 in patients at increased risk of their COVID-19 disease becoming severe and who do not require supplemental oxygen. Some monoclonal antibodies are also approved for preventing COVID-19.

The ETF statement does not refer to RoActemra, another monoclonal antibody, which does not target the virus but acts as a modulator of the immune response and is used with a corticosteroid medicine in patients who require extra oxygen or mechanical ventilation (breathing assisted by a machine).

More information about other medicines authorised for treating COVID-19, including Paxlovid and Veklury, is available on EMA’s COVID-19 treatments page.