Monoclonal Antibodies Therapies for Cancer

Your immune system normally produces antibodies in response to biological "tags" on invaders. These tags that antibodies find are called antigens. The immune system can recognize antigens on invading bacteria and antigens on your own cells—when they have become virus-infected or cancerous, for instance. When an antibody binds to its antigen, it can recruit the immune system to destroy the target.

Monoclonal antibodies, or mAbs, are used to treat many different diseases, including some types of cancer. There is a lot of enthusiasm about mAbs and their potential to more selectively target cancer cells. Used together with chemotherapy, certain mAbs have lengthened survival times.

What Does Monoclonal Mean?

Monoclonal means "just one clone," which requires further explanation. Normally, when your immune system sees an invader, it will develop a nice variety of antibodies—all different kinds, to target all different nooks and crannies on the invader's surface. These antibodies are polyclonal antibodies, meaning that several different "clones" or families of immune cells combine efforts to make an entire portfolio of antibodies to attack the invader.

Scientists have become increasingly precise in fighting cancer, and targeting a bunch of different nooks, crannies, and tags on a cancer cell might sound good, but is not necessarily practical. For example, what if one of the targets on a cancer cell turns out to be present in abundance on all normal, healthy cells too?

Monoclonal antibodies, then, are artificial antibodies made in a lab by scientists—antibodies designed to target a single, specific known antigen of interest—often a protein on the surface of cancer cells.

Examples of mAb therapies for blood cancers include Rituxan (rituximab), and Gazyva (obinutuzumab), both of which target the CD20 antigen. CD20 is one of many different targets on the surface of B-cells, or B-lymphocytes, which give rise to many lymphomas.

How Do Monoclonal Antibodies Work?

MAbs can work as beacons, or signals, to alert the immune system attack:

  • Naked or unconjugated mAbs attach to antigens on the cancer cell, acting as a signal for the body's immune system to seek and destroy.
  • Rituximab and obinutuzumab are examples of this type of mAb. They make use of your immune system to kill the cancer cells. They also lower the number of healthy B-cells, which have the CD20 tag, but healthy B-cells can be replenished.

MAbs can also be designed to deliver a toxic payload when they find their target:

  • Conjugated mAbs bind to targets just like naked mAbs, but they deliver drugs, toxins, or radiation directly to the cancer cell.
  • An example of a conjugated mAB is Zevalin (ibritumomab tiuxetan). Zevalin is a CD20-directed radiotherapeutic mAb for relapsed or refractory low-grade follicular B-cell non-Hodgkin’s lymphoma (NHL). It's also used for previously untreated follicular NHL with a partial or complete response to first-line chemotherapy.

How Are Monoclonal Antibodies Given?

Monoclonal antibodies are given intravenously (through a vein) in the hospital or at the clinic. Other drugs may be given beforehand to decrease the likelihood of reactions and side effects.

Importantly, when used as a treatment for leukemia or lymphoma, monoclonal antibodies are often given in combination with traditional chemotherapy. The number of scheduled times, or cycles, that a mAb is given in the course of treatment depends on a variety of different factors, including some factors that may be specific to you and your illness.

Side Effects of Monoclonal Antibodies

While side effects of mAb therapies are not the same as with chemotherapy, they do occur. Some side effects may be similar to allergic-type reactions. Adverse effects may depend on the particular mAb given, the individual patient and his or her pre-existing health conditions, the type of malignancy and many other factors. Some common mAb-associated side effects include the following:

Updated by Tom Iarocci, MD.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Berg JM. Immune Responses Against Self-Antigens Are Suppressed. Biochemistry. 5th edition. Published 2002

  2. Chaplin DD. Overview of the immune responseJ Allergy Clin Immunol. 2010;125(2 Suppl 2):S3–S23. doi:10.1016/j.jaci.2009.12.980

  3. Mellstedt H. Monoclonal antibodies in human cancer. Drugs Today. 2003;39 Suppl C:1-16. PMID: 14988743

  4. Huang ZQ, Buchsbaum DJ. Monoclonal antibodies in the treatment of pancreatic cancerImmunotherapy. 2009;1(2):223–229. doi:10.2217/1750743X.1.2.223

  5. Lipman NS, Jackson LR, Trudel LJ, Weis-garcia F. Monoclonal versus polyclonal antibodies: distinguishing characteristics, applications, and information resources. ILAR J. 2005;46(3):258-68. doi:10.1093/ilar.46.3.258

  6. Deyev SM, Lebedenko EN. Modern Technologies for Creating Synthetic Antibodies for Clinical applicationActa Naturae. 2009;1(1):32–50. PMID: 22649585

  7. Mohammed R, Milne A, Kayani K, Ojha U. How the discovery of rituximab impacted the treatment of B-cell non-Hodgkin's lymphomasJ Blood Med. 2019;10:71–84. Published 2019 Feb 27. doi:10.2147/JBM.S190784

  8. Papaioannou NE, Beniata OV, Vitsos P, Tsitsilonis O, Samara P. Harnessing the immune system to improve cancer therapyAnn Transl Med. 2016;4(14):261. doi:10.21037/atm.2016.04.01

  9. Casan JML, Wong J, Northcott MJ, Opat S. Anti-CD20 monoclonal antibodies: reviewing a revolutionHum Vaccin Immunother. 2018;14(12):2820–2841. doi:10.1080/21645515.2018.1508624

  10. Coulson A, Levy A, Gossell-Williams M. Monoclonal Antibodies in Cancer Therapy: Mechanisms, Successes and LimitationsWest Indian Med J. 2014;63(6):650–654. doi:10.7727/wimj.2013.241

  11. Jacobs SA. Yttrium ibritumomab tiuxetan in the treatment of non-Hodgkin's lymphoma: current status and future prospectsBiologics. 2007;1(3):215–227. PMID: 19707332

  12. Kahl B. Chemotherapy combinations with monoclonal antibodies in non-Hodgkin's lymphomaSemin Hematol. 2008;45(2):90–94. doi:10.1053/j.seminhematol.2008.02.003

  13. Adler MJ, Dimitrov DS. Therapeutic antibodies against cancerHematol Oncol Clin North Am. 2012;26(3):447–vii. doi:10.1016/j.hoc.2012.02.013

  14. Baldo BA. Adverse events to monoclonal antibodies used for cancer therapy: Focus on hypersensitivity responsesOncoimmunology. 2013;2(10):e26333. doi:10.4161/onci.26333

  15. Larson SM, Carrasquillo JA, Cheung NK, Press OW. Radioimmunotherapy of human tumours [published correction appears in Nat Rev Cancer. 2015 Aug;15(8):509]. Nat Rev Cancer. 2015;15(6):347–360. doi:10.1038/nrc3925

Additional Reading

  • Varricchio CG. A Cancer Source Book for Nurses. Sudbury, MA: Jones and Bartlett Publishers; 2004.

  • Yarbro CH. Cancer Nursing: Principles and Practice. Burlington, Mass: Jones & Bartlett Learning; 2018.