According to Cancer Research UK, the prevalence of cancer cases has risen by 12% since the 1990s. There is now a 1 in 2 chance of being diagnosed with cancer in one’s lifetime.
These shocking statistics highlight the importance of cancer treatment and prevention. Immunotherapy is a rapidly growing area of development in cancer treatments. Immunotherapy helps assist specific parts of a person’s immune system to help fight disease such as cancer.
What is our immune system?
Our immune system is fundamental in protecting us from diseases such as cancer. It is made up of a network of cells, tissues and organs that work to protect the body. One of the most important elements of our immune system is our white blood cells, also known as leukocytes/lymphocytes.
They are at the forefront of our immunity and are responsible for seeking out and destroying disease-causing organisms and substances. There are two types of lymphocytes: B cells and T cells. The B cells produce antibodies that are used to attack bacteria, viruses etc.
The immune system works by keeping a record of all substances found in the body. Therefore, any new substance the immune system doesn’t recognise is treated as a threat and is attacked by the immune system.
However, it is more difficult for the immune system to target cancer cells. Cancer starts when cells become altered and start to grow out of control. Therefore, the development of cancer often means the immune system doesn’t always detect cancer cells as foreign.
Immunotherapy can work in different ways:
- Stimulating the immune system so it can work harder and smarter to attack cancer cells
- Facilitate the immune system via components like man-made immune system proteins
There are already many types of immunotherapy being used to treat cancer with ongoing new developments:
- Monoclonal antibodies (mAbs) – These are man-made forms of immune system proteins. Antibodies are vital in combating cancer because they can target a very specific part of a cancer cell.
Work in this field is looking at making monoclonal antibodies safer. Being proteins a side effect of this treatment is an immune response against the mAbs themselves.
Current research into mAbs is looking to getting an immune response by combining two antibodies together. One part of the antibody attaches to the cancer cell, the other to an immune cell to bring them together and remove cancer cells.
- Immune checkpoint inhibitors – These drugs are designed to help the immune system recognise and attack cancer cells. The immune system has checkpoint proteins that help prevent it from attacking normal cells in the body.
Some cancer cells are able to manipulate these checkpoints to avoid being attacked by the immune system. Therefore, new approaches in this area are looking at combining treatments that target different checkpoints without severe side effects.
- Cancer vaccines – Vaccines are substances administrated to the body to create an immune response against certain diseases. Vaccines for cancer are still under development as cancer cells have different ways of escaping the immune system.
New research into this area is looking at the effect of giving the vaccine with other substances to boost the immune system or along side other types of cancer treatments. There are many different types of cancer vaccines being investigated including tumour cell, antigen and dendritic cell vaccines.
- Other, non-specific immunotherapies – Treatments to boost specific parts of the immune system. Due to the complexity of this area, treatments are currently only available through clinical trials.
Examples of treatments include:
- Chimeric antigen receptor (CAR) T-cell therapy
- Tumor-infiltrating lymphocytes and interleukin-2 (IL-2)