Merck Manual

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Peter J. Delves

, PhD, University College London, London, UK

Reviewed/Revised Feb 2024

Several types (classes) of immunotherapeutic medications have been developed. Some of the most common classes are

  • Cytokines and cytokine receptors

  • Fusion proteins

  • Monoclonal antibodies

Cytokines and Cytokine Receptors

Cytokines are the chemical messengers of the immune system. White blood cells White blood cells The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more and certain other cells of the immune system produce cytokines when they detect a foreign substance (antigen Overview of the Immune System ). Examples of cytokines include interferons and interleukins. Cytokines transmit their message by attaching to specific molecules called receptors on the surface of another cell. Cytokines and their receptors are a bit like a key and lock. Different cytokines have different receptors.

Cytokines or their receptors can be produced in a laboratory. When given to a person, the artificial cytokine or cytokine receptor can be used to modify the person's natural immune response and treat many diseases.

Cytokines or cytokine receptors are used to do the following:

Fusion Proteins

Fusion proteins are compounds that are produced in the laboratory and combine or "fuse" two different proteins with desirable immune-modifying and disease-fighting traits to form a single drug. When given to a person, the newly created fusion protein can be used to modify the natural immune response and treat many diseases. An example of a fusion protein is the medication etanercept, which fuses a cytokine receptor with an antibody.

Fusion proteins are used to do the following:

Monoclonal Antibodies

Monoclonal antibodies (mAbs) are antibodies that are produced in a laboratory from living cells that have been altered to produce the desired antibody. When injected into a person's bloodstream, they act like the antibodies produced in the human body Antibodies One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more Antibodies . Monoclonal antibodies are usually designed to attack cancer cells or the substances that cause inflammation. An example is rituximab, used to treat many disorders, including rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more Rheumatoid Arthritis (RA) .

Monoclonal antibodies are used to do the following:

Because monoclonal antibodies are often used to suppress the immune system, they can have significant side effects such as an increased risk of infection or cancer and can also result in autoimmune disorders Autoimmune Disorders An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues. What triggers an autoimmune disorder is not known. Symptoms vary depending... read more .

Drugs Mentioned In This Article

Generic Name Select Brand Names
RIABNI, Rituxan, RUXIENCE, truxima
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