What are human monoclonal antibodies?

An antibody is a protein produced by the body's immune system in response to antigens, which are harmful substances. Antigens include bacteria, fungi, parasites, viruses, chemicals, and other substances the immune system identifies as foreign. Sometimes the body mistakenly identifies normal tissues as foreign and produces antibodies against the tissue. This is the underlying cause of autoimmune conditions such as rheumatoid arthritis and multiple sclerosis or MS.

Antibodies are naturally produced by the immune system. However, scientists can produce antibodies in the lab that mimic the action of the immune system. These man-made (synthetic) antibodies act against proteins that attack normal tissues in people with autoimmune disorders. Man-made antibodies are produced by introducing human genes that produce antibodies into mice or another suitable mammal. The mice then are vaccinated with the antigen that scientists want to produce antibodies against. This causes the immune cells of the mice to produce the desired human antibody. The term monoclonal antibody means that the man-made antibody is synthesized from cloned immune cells, and the identical monoclonal antibody produced binds to one type of antigen. Polyclonal antibodies are synthesized from different immune cells and the antibodies produced bind to multiple antigens.

As of October 2020, drug companies Regeneron and Eli Lilly were conducting clinical trials on two monoclonal antibody therapy cocktails for bridge treatment of the coronavirus disease COVID-19. Early results are promising, but there is far from enough data to show whether monoclonal antibody therapy is broadly useful against the SARS-CoV-2 virus that causes COVID-19.

List and types of monoclonal antibodies (FDA approved)

Here is a list of examples some FDA-approved monoclonal antibody drugs.

Each monoclonal antibody listed above has a role in treating a targeted disease (for example, basiliximab treats transplant rejection while belimumab treats systemic lupus erythematosus).


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What are the uses for monoclonal antibodies?

The use of monoclonal antibodies to treat diseases is called immunotherapy therapy because each type of monoclonal antibody will target a specific targeted antigen in the body.

Uses for monoclonal antibodies include:

In these conditions the monoclonal antibody targets and interferes with the action of a chemical or receptor that is involved in the development of the condition that is being treated. For example, a monoclonal antibody used for treating cancer may block a receptor that cancer cells use for preventing the immune system from the destroying the cancer cell. Blocking this receptor allows the immune system to recognize cancer cells and destroy them.

The monoclonal antibodies for the COVID-19 pandemic coronavirus may soon reach the market late in 2020 under emergency use authorization from the FDA, according to the magazine Science, but the manufacturers were still in talks with the agency about this matter as of this update.

What are the side effects of monoclonal antibodies?

These side effects are compiled from side effects listed for several monoclonal antibodies. Each type of monoclonal antibody has its own side effect profile and may or may not cause some of the side effects listed here.

Common side effects of monoclonal antibodies include:

Other side effects of monoclonal antibodies include:

Serious side effects of monoclonal antibodies may include one or more of the following:

What drugs or other compounds interact with monoclonal antibodies?

  • Serious infections are more likely to occur when monoclonal antibodies are combined with other drugs that suppress the immune system (for example, steroids).
  • Another example of drug interaction is that the drug methotrexate reduces the absorption of adalimumab (monoclonal antibody) by 29%-49%, but no adjustments to the dose of adalimumab need to be made when methotrexate is given concomitantly.
  • Monoclonal antibodies may interfere with the effectiveness of vaccines. Live vaccines, including attenuated vaccines, should not be used while patients are being treated with monoclonal antibodies. Patients should complete all recommended immunizations prior to receiving monoclonal antibodies.

What formulations of monoclonal antibodies are available?

Monoclonal antibodies are designed to be administered by injection. They are supplied as:

  • Lyophilized powder for reconstitution
  • Solution for injection

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Is monoclonal antibody therapy safe during pregnancy or while breastfeeding?

  • Monoclonal antibodies have not been adequately studied in pregnant women or women who are breastfeeding. Some monoclonal antibodies, for example, nivolumab (Opdivo) and pembrolizumab (Keytruda), may be harmful to the fetus because of their mechanism of action and from other results obtained from animal studies.
  • It is not known whether monoclonal antibodies are present in breast milk. Mothers who are breastfeeding should decide whether to stop or discontinue the monoclonal antibody because many drugs, including large proteins like monoclonal antibodies, are excreted in breast milk and there is a risk of serious adverse effects in the infant.


Monoclonal antibodies or MABs are one type of biological therapy to treat certain types of cancer and arthritis, multiple sclerosis, heart disease, lupus, inflammatory bowel disease (Crohn's disease and ulcerative colitis), psoriasis, and transplant rejection. Review drug interactions, dosing, preparations, and pregnancy and breastfeeding safety information prior to using any medication.

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Medically Reviewed on 10/19/2020
FDA approved prescribing information for monoclonal antibodies.

Geskin LJ. "Monoclonal Antibodies." Dermatol Clin. 2015 Oct;33 (4):777-86.

Some information provided by Charles Patrick Davis, MD, PhD