The Promise Of Immunotherapy

Immunotherapy approaches in cancer therapy were first used about 100 years ago when Dr. William Coley, of the Sloan-Kettering Institute, showed that he could control the growth of some cancers and cure a few advanced cancers with injections of a mixed vaccine of streptococcal and staphylococcal bacteria which became known as Coley's toxin. The tuberculosis vaccine, Bacillus Calmette- Guerin (BCG), developed in 1922, is known to stimulate the immune system and is now used to treat bladder cancers.

It took many years of research to produce the first successful examples of immunotherapies for cancer. These new treatments, sometimes referred to as biological response modifiers or as biological therapies, include:

	Interferons and other cytokines Monoclonal antibodies Cancer vaccines

What are the potential disadvantages of immunotherapy?

Immunotherapy may work in some people and not in others depending upon the design of the immunotherapy, the ability of the immunotherapy to produce an immune response and/or anti-cancer activity, and other components contributing to the disease.

• Some immunotherapy drugs have severe side effects
• High cost
• Possible short-term efficacy

What is the availability of immunotherapy?

Some immunotherapy drugs have been approved by the FDA for use against specific types of cancer. Immunotherapy is also available through clinical trials (research studies in people).

Health insurance companies may or may not provide coverage for immunotherapy, which can be very expensive. Ask your oncologist about immunotherapy for your diagnosis, or a possible combination it with other cancer therapies.

What is the future of immunotherapy?

Immunotherapy seems to offer great promise as a new tool in cancer treatment, but it is still very much in its infancy. However,immunotherapies involving certain cytokines and antibodies have become part of standard cancer treatment.

	As you can see from this image, antibodies are very specific for their corresponding antigen. This makes them valuable as a tool for targeting various antigen receptors on cancer cells.
Image courtesy of: Genomics.energy.gov

Other types of immunotherapy remain experimental. Although many clinical trials using new forms of immunotherapy are in progress, an enormous amount of research remains to be done before the findings can be widely applied.

As researchers continue to learn more about and better understand the immune system they will be able to:

• Understand other mechanisms involved in cancer growth associated with immunotherapy, including the relationship between the immune system and the entire body;
• Better identify the sub-groups of people with certain cancers who are more likely to benefit from specific immunotherapy;
• Better understand the molecular and cellular characteristics involved as to why immunotherapy works or does not work in individual people;
• Continue to develop new immunotherapies; and
• Develop new combinations of traditional cancer therapies with immunotherapy.

According to Lloyd J. Old, MD, Director of the Cancer Vaccine Collaborative affiliated with the Ludwig Institute for Cancer Research, the three key questions that are critical to developing more effective immune-based treatments include the following.

1. How does the immune system recognize cancer?
2. What are the antigens that the immune system targets?
3. How can you strengthen the immune response?

More Information Sources

• American Cancer Society Immunotherapy
• Cancer Treatment Centers of America Immunotherapy
• Mayo Clinic Cancer Immunology and Immunotherapy Program
• Medline Plus Immune System and Disorders
• National Cancer Institute Understanding Cancer Series: The Immune System
• National Cancer Institute Tumor Immunology Think Tank