Monoclonal antibody therapy

For people at high risk of getting very sick from COVID-19, monoclonal antibody treatment given early can significantly reduce the risk of progressing to severe COVID-19 disease and needing hospitalization. The treatment can also shorten the duration of COVID-19 symptoms.

What is a monoclonal antibody?

Antibodies are proteins that exist in our bodies as part of our immune system to recognize and defend against harmful viruses and bacteria.

Monoclonal antibodies are made in a laboratory and designed to target a specific virus or bacteria.

How do monoclonal antibodies work against COVID-19?

Monoclonal antibodies against COVID-19 attach to the virus to block it from entering human cells.

The monoclonal antibody protein also “marks” the virus to be broken down by the immune system and cleared from the body.

How is monoclonal antibody treatment done?

provider explaining a treatment

Treatment with COVID-19 monoclonal antibodies involves a one-time intravenous (IV) infusion of a monoclonal antibody product.

Currently UCHealth uses this product, available by FDA Emergency Use Authorization:

  • Casirivimab/imdevimab (made by Regeneron Pharmaceuticals)

Benefits and risks of monoclonal antibody therapy

Reducing disease severity

For people at high risk of getting very sick from COVID-19, monoclonal antibody treatment given early can significantly reduce the risk of progressing to severe COVID-19 disease and needing hospitalization. The treatment can also shorten the duration of COVID-19 symptoms.

Possible side effects

Most people tolerate monoclonal antibody infusions very well. Some people may experience infusion-related side effects, such as nausea and dizziness, that are short-lived and go away on their own. As with any medication, there is the potential for mild or more severe allergic reactions, which are uncommon.

How to get monoclonal antibody therapy

UCHealth currently operates infusion sites in the northern, central and southern regions of Colorado.

Please speak with your health care provider or schedule a visit with UCHealth Virtual Urgent Care to determine if you are eligible for monoclonal antibody treatment and to discuss if it may be right for you. Patients who are at high risk and most likely to benefit from this treatment may be considered. Those not belonging to one of the high-risk groups will not be considered under the FDA guidance at this time.

If your provider determines that you are eligible, they will submit an order to one of our infusion sites. Due to increasing cases of COVID-19 and a high demand for monoclonal antibody treatment, all orders will be reviewed and prioritization will be given based on patient risk and treatment availability.

Provider and patient having a discussion

Frequently asked questions

Some studies have shown success with preventing COVID-19 when used in people who have been exposed to COVID-19. However, monoclonal antibodies are currently not authorized to be used for prevention outside of clinical trials.

Increasing data from clinical trials show that when used early in the course of COVID-19, monoclonal antibodies can reduce the need for hospitalization and decrease the risk of death. For the greatest effect, treatment should be given as soon as possible, ideally within the first week after the start of symptoms.

Under the FDA Emergency Use Authorization, COVID-19 monoclonal antibodies can be used in people who are early in their disease course, not hospitalized for COVID-19, and are at high risk for progressing to severe disease.

Monoclonal antibodies have been shown to be safe in clinical trials, with a rate of adverse reactions that was not different from placebo. Allergic reactions are possible but are rare.

Monoclonal antibodies have been shown to be safe in clinical trials, with a rate of adverse reactions that was not different from placebo. Allergic reactions are possible, but rare. Side effects and allergic reactions can happen during or after the infusion.

 

COVID-19 monoclonal antibodies target the SARS-CoV-2 virus itself and not human cells, and have not been shown to cause cancer.

Monoclonal antibodies are carefully designed to recognize a single target (for example, a specific part of a specific virus). Sometimes two monoclonal antibodies, targeting different parts of a virus, are given in combination to increase the effectiveness of the treatment; these combinations are called monoclonal antibody cocktails.

Monoclonal antibodies are designed to target a very specific part of a virus or bacterium, and are carefully selected and tested for effectiveness.

Polyclonal antibodies refers to a mixture of many different antibodies—some good, and some not so good—that are produced as part of the body’s response to a foreign substance. Convalescent plasma (plasma that is taken from someone who has recovered from an infection) is an example of a substance that contains polyclonal antibodies.

Monoclonal antibodies are not considered immunotherapy, because they do not change the body’s own immune response to the virus. Rather, monoclonal antibodies provide passive immunity, by providing antibodies that the body has not yet had a chance to generate on its own. This can be especially important for people whose bodies have difficulty making antibodies, or where a disease progresses too quickly for the body to make antibodies fast enough to stop it.

Other types of monoclonal antibodies that have already been in use for many years include those for treating hepatitis B and rabies exposures.

Most monoclonal antibodies for COVID-19 are derived from human antibodies that are isolated from a person who has previously recovered from COVID-19.

Antibodies are selected based on their high potency to neutralize the virus and their potential to remain effective when the virus mutates. These antibodies are produced in the laboratory by growing cells that produce the desired antibodies, and then harvesting the proteins they make.

Currently, there are no data about the safety or efficacy of COVID-19 vaccines in people who have recently received monoclonal antibodies.

Since it is theoretically possible that vaccination might be less effective soon after receiving monoclonal antibodies (because the antibodies might attach to the vaccine inside your body), it is recommended that patients wait 90 days after monoclonal antibody treatment to receive a COVID-19 vaccine.

You should also know that because of the immune response to a COVID-19 infection, it is extremely rare for people to get a second infection within 90 days of having a case of COVID-19.

The current recommendation is that COVID-19 vaccination be delayed for at least 90 days for anyone that has received convalescent plasma or was treated with a monoclonal antibody. This may help to avoid interference of the treatment with vaccine-induced immune responses.