Understanding Monoclonal Antibody Treatment for COVID-19

Aaron S. Weinberg MD, MPhil
September 21, 2021
4 mins

At the end of May 2021, the FDA (United States Food and Drug Administration) issued an EUA (emergency use authorization) for the use of monoclonal antibody therapy as an outpatient treatment option for mild to moderate COVID-19. As COVID-19 infections continue to rise, the CDC is recommending that eligible high-risk individuals consider monoclonal antibody therapy to help lower the risk of potentially life-threatening illness from the virus. 

What Is Monoclonal Antibody Therapy? 

Monoclonal antibodies are laboratory-made proteins that mimic the immune system’s ability to fight harmful antigens, including viruses. Scientists have developed different products, including Sotrovimab and REGEN-COV, a monoclonal antibody that is designed specifically to defend against the spike protein of SARS-CoV-2. 

It does this by blocking the virus’s attachment and entry into human cells. When the antibody therapy is administered, it provides the person with antibodies before their own body begins to create them. This gives the person’s immune system a head start on neutralizing the virus, before the virus infects their cells. Because of this, the therapy is most effective when provided closest to the time of exposure to COVID-19. Monoclonal therapy can be provided either through an IV (intravenously) or under the skin (subcutaneously).

The FDA has recently provided an issuance of the EUA for monoclonal antibody treatment, which is different from FDA approval. When determining whether to issue an EUA, the FDA carefully evaluates the current evidence available on the product, and balances any potential or known risks with the potential or known benefits. When it comes to monoclonal antibody treatment, the FDA determined that the potential benefits of the therapy outweigh any potential risks for the drug. 

Is Monoclonal Antibody Therapy Effective?

The current data provided by the FDA for Sotrovimab is based on an analysis from a randomized, double-blind placebo-controlled clinical trial in 583 non-hospitalized adults. In the study, every participating adult was experiencing mild-to-moderate COVID-19 symptoms and had tested positive for COVID-19. 

Of these patients, hospitalization or death occurred in 21 patients who received the placebo, compared with three patients treated with Sotrovimab, an 85 percent reduction.

The current data provided by the FDA for REGEN-COV is based on a randomized, double-blind, placebo-controlled clinical trial evaluating REGEN-COV for the treatment of 4,567 subjects with mild to moderate COVID-19.

Of those subjects, COVID-19-related hospitalization or death occurred in only seven subjects, compared with 24 subjects who received a placebo, a 70 percent reduction. 

The FDA is also carefully monitoring the effectiveness of monoclonal antibody therapy against additional variants of COVID-19. Past monoclonal antibody therapies have been taken off the market, as they no longer work for the circulating variants; however, current laboratory testing shows that monoclonal therapy is effective against the circulating variants first reported in the United Kingdom, South Africa, Brazil, California, New York and India. The most severe yet rare side effect of monoclonal therapy is anaphylaxis (severe allergic reaction). Other potential side effects include infusion-related reactions, such as flushing, rash, or diarrhea, or if administered subcutaneously, pain, swelling, or redness at the injection site.

Who Is Eligible to Receive Monoclonal Antibody Therapy?

According to the FDA, monoclonal antibody therapy currently has an EUA as an intervention for post-COVID-19 exposure and for the treatment of mild to moderate COVID-19 in high-risk adults and pediatric patients 12 years old or older. 

Prophylaxis (an action taken to prevent disease) is for people who have been closely exposed to someone with COVID-19 but are not yet infected. Treatment is for people who have tested positive for SARS-CoV-2 and are at high risk for a progression to severe COVID-19. High-risk patients include people who are aged 65 years old and older and people who have certain underlying medical conditions, including:

     • Diabetes

     • Heart conditions

     • Immune disorders

     • Lung conditions, including asthma 

     • Medical-related technological dependence, such as tracheostomy, gastrostomy, or positive pressure ventilation (unrelated to COVID-19)

     • Neurodevelopmental disorders, such as cerebral palsy

     • Obesity (a body mass index (BMI) ≥25 kg/m² or higher [BMI is a mathematical formula that divides a person’s weight by the square of their height; the resulting number is used to place the person into one of eight bodyweight “categories.” While BMI is frequently used as a guide, many healthcare professionals dispute its accuracy in determining a person’s healthy weight.])

     • Pregnancy

     • Sickle cell disease

Treatment can be provided to people regardless of their vaccination status. However, only unvaccinated people can receive the therapy for prophylaxis (as well as vaccinated people who have immunosuppressive disease or are undergoing immunosuppressive therapy).

Monoclonal therapy is not approved for people who are currently hospitalized due to COVID-19 or people who require new oxygen therapy or an increase in their baseline oxygen therapy due to COVID-19, as the treatment has currently not shown any benefit in these patient populations. 

Monoclonal Antibody Therapy at Carbon Health

If you have tested positive for COVID-19 and believe you are eligible, we’re here to help by providing additional access to this potentially life-saving treatment. 

At Carbon Health, we will be offering monoclonal antibody treatment (REGEN-COV) for people who qualify. Patients will be able to book a visit via our COVID Positive Program and can also access the treatment if they have tested positive for COVID-19 at one of our locations. 

Carbon Health providers are standing by to ensure you receive the care you deserve, fast. Book an appointment via carbonhealth.com or our app today. 

Carbon Health’s medical content is reviewed and approved by healthcare professionals before it is published. But note that our knowledge and understanding of COVID-19 are developing and changing very rapidly; if you have questions or concerns about COVID-19 precautions, treatments, and vaccinations, please talk to your healthcare provider.

Aaron S. Weinberg MD, MPhil

Aaron S. Weinberg, MD, MPhil, is Director of Program Development at Carbon Health and triple board-certified in Pulmonary, Critical Care, and Internal Medicine.