Biological therapies use substances that occur naturally in the body to destroy cancer cells.
The main types of biological therapies are:
- Monoclonal antibodies
- Cancer growth inhibitors
- Angiogenesis inhibitors
- Gene therapy
When we are exposed to infection (antigens), our immune system produces antibodies so that if we are exposed to the infection again, the antibodies will recognise it and know to fight it quickly.
Monoclonal antibodies are antibodies made in a laboratory. They aim to destroy some types of cancer cells while causing minimum damage to normal cells. They locate and attach to certain proteins on the surface of particular cancer cells receptors, and ‘lock’ onto them (like a key in a lock).
Once the monoclonal antibody has ‘locked’ into a receptor it can
- Cause the body´s immune system to attack the cancer cells
- Cause the cell to destroy itself
- Block the receptor from ‘locking’ with another protein, stopping cancer cell growth
There are many different types of monoclonal antibodies; each one is made to attach to a different part of the cancer cell. Monoclonal antibodies can be used with chemotherapy or radiotherapy. The chemotherapy drug or radioactive substance connects to the monoclonal antibody. In this way the treatment is delivered directly to the cancer cell. Your doctor may refer to this as ‘targeted therapy’. Monoclonal drugs include:
- Avastin (Bevacizumab)
- Bexxar (Iodine131 tositumomab)
- Erbitux (Cetuximab)
- Herceptin (Trastuzumab)
- Ipilimumab (Yervoy)
- Mabcampath (Alemtuzumab)
- Mabthera (Rituximab)
- Mylotarg (Gemtuzumab)
- Vectibix (Panitumumab)
- Zevalin (90Y-Ibritumomab tiuxetan)
Cancer growth inhibitors:
Cancer cells need to communicate with each other in order to grow and multiply; they do this through a series of chemical reactions. Drugs called cancer growth inhibitors interrupt the communication process and in this way prevent the cancer from developing. Each cancer growth inhibitor works in a different way. Cancer growth inhibitor drugs include:
- Crizotinib (Xalkori)
- Glivec (Imatinib)
- Iressa (Gefitinib)
- Nexavar (Sorafenib)
- Sutent (Sunitinib)
- Sprycel (Dasatinib)
- Tarceva (Eroltinib)
- Tyverb (Lapatinib)
- Velcade (Bortezomib)
- Vemurafenib (Zelboraf)
Angiogenesis is the creation of new blood vessels. In a healthy person, angiogenesis is part of the normal healing process, e.g. wound healing. In cancer, this process provides a tumour with its own blood supply, and carries vital nutrients to the tumour. This, in turn, promotes tumour growth. A tumour cannot survive without a network of blood vessels.
Anti-angiogenesis treatment is the use of drugs or other substances to stop tumours from developing these new blood vessels. Without a blood supply, cancer cannot multiply and spread. These therapies aim to block angiogenesis. Research trials are still underway, to determine the most powerful anti-Angiogenic therapies. Trials combine chemotherapy, biotherapies and radiotherapy with anti-angiogenic therapy.
Angiogenesis inhibitors include:
Other biological therapies
- Mifamurtide (Mepact®)
Vaccines have been used for many years as a way of preventing infectious illnesses like flu, tuberculosis (TB), measles, mumps, typhoid and German measles. Vaccines stimulate the body’s immune system to recognise and fight abnormal ‘foreign’ cells in the body, such as viruses and bacteria.
Cancer vaccines are based on the same principle: they trigger your own immune system to respond to the presence of cancer cells. These vaccines don't just boost the immune system in general; they cause the immune system to attack cells with one or more specific antigens.
A cancer vaccine contains cancer cells, parts of cells, or pure antigens. The vaccine increases the immune response against cancer cells that are already present in the body.
Gene therapy involves inserting genetic material (DNA or RNA) into cells to restore a missing function or to give the cells a new function. Because missing or damaged genes cause certain diseases such as cancer, it makes sense to try to treat these diseases by adding the missing gene(s) or fixing those that are damaged. But figuring out how to do this has not been easy. It will probably be several years before gene therapy is ready for use to the general public.
Interferon alpha is a manmade copy of a substance that the body makes naturally. The body makes interferon as part of the immune response. Interferon is used as a treatment for some types of cancer.