Monoclonal Antibodies - Targeted Cancer Therapies

Targeted Therapy For Leukemia And Lymphoma

Monoclonal antibody attacking a blood cancer cell.

What are Monoclonal Antibodies?

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 to 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 January 2016, TI.


    NCCN. Patient and Caregiver Resources. Targeted Therapies. Accessed January 2016.

    Iarocci, Thomas. Gazyva for Non-Hodgkin's Lymphoma. Accessed January 2016.

    Iarocci, Thomas. Blood Cancer and Anemia. Accessed January 2016. 

    Questions To Ask Your Doctor About Your Treatment

    The treatment of leukemia and lymphoma can be a long and stressful journey. It is important that you feel comfortable with how much information you have regarding your treatment so that you know what to expect and so that you feel able to make informed decisions regarding your care.

    You may want to write down some questions to ask to help you prepare.

    Some examples of questions you may want to ask your healthcare provider are:

    • What is this treatment?
    • How long will I need to get it?
    • How and where will this treatment be given to me?
    • How long is each treatment expected to take?
    • What side effects can I expect? Will I receive any medication to decrease side effects?
    • Will I be able to continue with my regular routine?
    • Will my health plan help to pay for this therapy? What will it cost?
    • How will I know if this treatment is working?
    • Will I need more treatment when this is done?
    • What problems or symptoms should I report right away?

    It is good to make a few notes while you are at your appointment. This will help you to remember facts when you get home. Ask for clarification if there is something you are having a hard time understanding. Your healthcare provider understands that this is all new to you, and wants you to have the information you need before you receive any therapies.


    Monoclonal antibodies have improved outcomes for many kinds of cancer, including leukemia and lymphoma. Their unique ability to kill cancer cells without undue toxic effects to healthy tissues make them very different from traditional chemotherapy drugs, especially in terms of their potential side effects.

    Monoclonal antibody therapy research continues with the goal of increasing and prolonging remissions in leukemia and lymphoma patients.


    Abernathy, E.(1997). Biotherapy. In Varricchio, C.(Ed.) A Cancer Source Book for Nurses -7th ed. (pp.379-390). Atlanta, Georgia: The American Cancer Society Inc.

    Battiato, L. and Wheeler, V.(2000). Biotherapy. In Yarbro,C., Frogge, M.,Goodman, M., et al (Eds.) Cancer Nursing Principles and Practice-5th ed. (pp. 1244-1269). London, England: Jones and Bartlett Publishers International

    R.S. Cvetkovic and C.M. Perry "Rituximab: a review of its use in non-Hodgkin's lymphoma and chronic lymphocytic leukaemia." Drugs 2006 66(6): 791-820.

    Continue Reading