Cancer Vaccines

1. Topics To Be Covered Cancer Vaccines Introduction Types How do cancer vaccines Work How are Cancer Vaccines Made Possible Side Effects FDA Approved Cancer Vaccines

2. Introduction • Cancer vaccines are medicines that belong to a class of substances known as biological response modifiers. Biological response modifiers work by stimulating or restoring the immune system’s ability to fight infections and disease. • The fact that immune system may prevent the occurrence of tumours is documented in immunodeficient mice and humans in which cancer incidence is much higher than immunocompetent hosts. • In recent years it also has been established that immune system may also influence the clinical outcome of patients with established tumours. • Some cancers are caused by viruses. Vaccines that help protect against infections with these viruses might also help prevent some of these cancers.Examples are Human Papilloma virus, HBV and HCV. http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/immunotherapy-cancer-vaccines http://www.medscape.org/viewarticle/440750

3. Vaccine Types Two broad categories of cancer vaccines: • Preventive (or prophylactic) vaccines:- They prevent cancer from developing in healthy people. These are traditional vaccines in that they target the viruses that can cause certain cancers. • Treatment (or therapeutic) vaccines:-These vaccines try to get the immune system to mount an attack against cancer cells in the body This vaccine uses cancer cells, parts of cells, or pure antigens to increase the immune response against cancer cells that are already in the body. Adjuvants are used to boost the immune response even further. http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/immunotherapy-cancer-vaccines

4. How Do Cancer Vaccines Work? Cancer Preventive Vaccine • Cancer preventive vaccines target infectious agents that cause or contribute to the development of cancer . • They are similar to traditional vaccines, which help prevent infectious diseases, such as measles or polio, by protecting the body against infection. • Both cancer preventive vaccines and traditional vaccines are based on antigens that are carried by infectious agents and that are relatively easy for the immune system to recognize as foreign. http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/immunotherapy-cancer-vaccines

5. ۔۔۔۔۔Continued Cancer Treatment Vaccines • Cancer treatment vaccines are designed to treat cancers that have already developed. They are intended to delay or stop cancer cell growth; to cause tumor shrinkage; to prevent cancer from coming back; or to eliminate cancer cells that have not been killed by other forms of treatment. • As tumors grow, they themselves can secrete immunosuppressive factors that downregulate immune system activation. • Current strategies are focused on making "self" more immunogenic by using immune system activators, supplying antigen-presenting cells, or actually predigesting some of these tumor antigen proteins into immunogenic peptides. • To be effective, cancer treatment vaccines must achieve two goals. First, like traditional vaccines and cancer preventive vaccines, cancer treatment vaccines must stimulate specific immune responses against the correct target. Second, the immune responses must be powerful enough to overcome the barriers that cancer cells use to protect themselves from attack by B cells and killer T cells See the Notes for References.

6. How Are Cancer Vaccines Made? • All cancer preventive vaccines approved by the FDA to date have been made using antigens from microbes that cause or contribute to the development of cancer. • Similarly, cancer treatment vaccines are made using antigens from cancer cells or modified versions of them. Antigens that have been used so far include proteins, carbohydrates (sugars), glycoproteins or glycopeptides (carbohydrate-protein combinations), and gangliosides (carbohydrate-lipid combinations). http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines

7. Continued….. • Tumor cell vaccines: These vaccines are made from actual cancer cells that have been removed during surgery. • Antigen vaccines: These vaccines boost the immune system by using only one antigen (or a few), rather than whole tumor cells that contain many thousands of antigen. • Dendritic cell vaccines: are autologous vaccines (made from the person in whom they will be used), and must be made individually for each patient. • DNA vaccines:DNA is the substance in cells that contains the genetic code for the proteins that cells make. Vectors can be given bits of DNA that code for protein antigens. When the vectors are then injected into the body, this DNA might be taken up by cells and can instruct them to make specific antigens, which would then provoke the desired immune response. • Vector-based vaccines: These vaccines use special delivery systems (called vectors) to make them more effective www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/immunotherapy-cancer-vaccines

8. Continued…. Adjuvants • Antigens and the substances discussed in previous slide are often not strong inducers of the immune response to make effective cancer treatment vaccines. Researchers often add extra ingredients, known as adjuvants, to treatment vaccines. • Adjuvants used for cancer vaccines come from many different sources. e.g. • Bacterium Bacillus Calmette-Guérin (BCG) • Substances produced by bacteria, such as Detox B • Natural or synthetic cytokines can also be used as adjuvants. http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines

9. Side Effects • Vaccines intended to prevent or treat cancer appear to have safety profiles comparable to those of traditional vaccines. • The most commonly reported side effect of cancer vaccines is inflammation at the site of injection, including redness, pain, swelling, warming of the skin, itchiness, and occasionally a rash. • People sometimes experience flu-like symptoms after receiving a cancer vaccine, including fever, chills, weakness, dizziness, nausea or vomiting, muscle ache, fatigue, headache, and occasional breathing difficulties. • Other, more serious health problems include asthma, appendicitis, pelvic inflammatory disease, and certain autoimmune diseases, including arthritis and systemic lupus erythematosus. http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines

10. FDA Approved Cancer Vaccines • Cancer Preventive Vaccine: Gardasil, manufactured by Merck & Company, is based on HPV antigens that are proteins. Cervarix, manufactured by GlaxoSmithKline, is a bivalent vaccine. It is composed of VLPs made with proteins from HPV types 16 and 18. The FDA has also approved a cancer preventive vaccine that protects against HBV infection because chronic HBV infection can lead to liver cancer. • Cancer Treatment Vaccines: In April 2010, the FDA approved the first cancer treatment vaccine. This vaccine, sipuleucel-T (Provenge®, manufactured by Dendreon), is approved for use in some men with metastatic prostate cancer. http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines

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