COVID THERAPIESThe WHO Has Advised Against the Use of Two Antibody Therapies Against COVID – Here’s What That Means

By Zania Stamataki

New guidance from the World Health Organization (WHO) strongly advises against using the antibody therapies sotrovimab and casirivimab-imdevimab to treat patients with COVID-19.

This guidance, published in the British Medical Journal, replaces previous conditional recommendations for the use of these drugs. It’s based on emerging evidence that they’re not likely to work against current COVID variants such as omicron.

This means that, at least for the time being, there are no recommended antibody therapies to treat COVID. There are, however, still other treatment options. Let’s take a look.

We know that severe COVID is driven by collateral damage from our own immune system. Some of the most effective COVID treatments are anti-inflammatory medicines, which reduce exaggerated immune responses against the virus. Strong evidence continues to support the use of drugs such as corticosteroids, anti-IL-6 and baricitinib.

Separate to anti-inflammatory drugs, we have two types of therapies that directly target SARS-CoV-2, the virus that causes COVID-19. These are antiviral drugs and antibody treatments.

Antiviral drugs allow the virus to enter our cells but prevent it from replicating, thereby reducing the impact of an infection.

Remdesivir, which was originally developed for hepatitis C, retains efficacy against omicron sub-variants BA.2.12.1, BA.4 and BA.5 in the lab. In the new guidance the WHO has conditionally recommended remdesivir to treat patients with severe COVID, but has advised against its use for patients who are critically unwell, based on results from a series of recent randomised trials.

Other antivirals include molnupiravir, which the WHO continues to conditionally recommend, and nirmatrelvir and ritonavir (a combination known as Paxlovid), which is recommended strongly. These drugs are taken orally, while remdesivir is administered intravenously.

Meanwhile, antibody therapies work by coating a protein on the surface of SARS-CoV-2, called the spike protein, thereby blocking the virus from entering human cells. They can also help eliminate infected cells which have been hijacked by the virus.

Sotrovimab is one such antibody therapy. It’s a monoclonal antibody, which means it only targets a specific region of the virus’s spike protein. In clinical trials conducted before the omicron variant emerged, sotrovimab reduced the risk of disease progression.

This led to its emergency authorisation by the US Food and Drug Administration and the UK’s Medicines and Healthcare products Regulatory Agency in 2021.