More than 100 years ago, there were serious attempts to try to harness the immune system. It came about when there were some sporadic observations of sick patient with uncontrolled infections ‑ of course, in those days, there weren’t antibiotics like we have today ‑ who would sometimes have remissions or regressions of their tumors. So there was a clear signal that something about the immune response could control a cancer. But the problem was you couldn’t harness it. It would happen sporadically. The biology responsible for it was elusive.
If we go back and see that world war II has given us Chemotherapy and that era continued till 2000. And next 15 years was the era of targeted therapy which increased the survival of cancer patients by 10-20%. With Imatinib therapy which was named magic bullet there was nearly 100% increment in survival .Other molecules followed e.g Rituximab, Cetuximab, Trastuzumab, Bevacizumab.
Immunotherapy is treatment that uses certain parts of a person’s immune system to fight diseases such as cancer. This can be done in a couple of ways:
- Stimulating your own immune system to work harder or smarter to attack cancer cells.
- Giving you immune system components, such as man-made immune system proteins.
Q.What the Immune system does?
The immune system keeps track of all of the substances normally found in the body. Any new substance that the immune system doesn’t recognize raises an alarm, causing the immune system to attack it. For example, germs contain substances such as certain proteins that are not normally found in the human body. The immune system sees these as “foreign” and attacks them. The immune response can destroy anything containing the foreign substance, such as germs or cancer cells.
The immune system has a tougher time targeting cancer cells, though. This is because cancer starts when cells become altered and start to grow out of control. The immune system doesn’t always recognize cancer cells as foreign.
Clearly there are limits on the immune system’s ability to fight cancer on its own, because many people with healthy immune systems still develop cancer. Sometimes the immune system doesn’t see the cancer cells as foreign because the cells aren’t different enough from normal cells. Sometimes the immune system recognizes the cancer cells, but the response might not be strong enough to destroy the cancer. Cancer cells themselves can also give off substances that keep the immune system in check.
To overcome this, researchers have found ways to help the immune system recognize cancer cells and strengthen its response so that it will destroy them.
Types of cancer Immunotherapy
The main types of immunotherapy now being used to treat cancer include:
- Monoclonal antibodies:- These are man-made versions of immune system proteins.
- Antibodies can be very useful in treating cancer because they can be designed to attack a very specific part of a cancer cell.
- Immune check point inhibitors:- These drugs basically take the ‘brakes’ off the immune system, which helps it recognize and attack cancer cells.
- Cancer vaccines: Vaccines are substances put into the body to start an immune response against certain diseases. We usually think of them as being given to healthy people to help prevent infections. But some vaccines can help prevent or treat cancer.
- Other, non-specific immunotherapies: These treatments boost the immune system in a general way, but this can still help the immune system attack cancer cells.
Immune check point Inhibitors
Drugs that target PD-1 or PD-L1:- PD-1 is a checkpoint protein on immune cells called T cells. It normally acts as a type of “off switch” that helps keep the T cells from attacking other cells in the body. It does this when it attaches to PD-L1, a protein on some normal (and cancer) cells. When PD-1 binds to PD-L1, it basically tells the T cell to leave the other cell alone. Some cancer cells have large amounts of PD-L1, which helps them evade immune attack.
Monoclonal antibodies that target either PD-1 or PD-L1 can boost the immune response against cancer cells and have shown a great deal of promise in treating certain cancers.
PD-1 inhibitors: Examples of drugs that target PD-1 include:
- Pembrolizumab (Keytruda)
- Nivolumab (Opdivo)
These drugs have been shown to be helpful in treating several types of cancer, including melanoma of the skin, non-small cell lung cancer, kidney cancer, head and neck cancers, and Hodgkin lymphoma. They are also being studied for use against many other types of cancer.
PD-L1 inhibitors: An example of a drug that targets PD-L1 is:
This drug can be used to treat bladder cancer, and is also being studied for use against other types of cancer.
Drugs that target CTLA-4
CTLA-4 is another protein on some T cells that acts as a type of “off switch” to keep the immune system in check.
Ipilimumab (Yervoy) is a monoclonal antibody that attaches to CTLA-4 and stops it from working. This can boost the body’s immune response against cancer cells.
This drug is used to treat melanoma of the skin. It is also being studied for use against other cancers.
Managing side effects
Immunotherapy can cause a variety of side effects, including fatigue, nausea, mouth sores, diarrhea, high blood pressure and fluid buildup, usually in the legs. Breast cancer patients, in particular, may experience fever, chills, pain, weakness, vomiting, headaches and rashes. The side effects of immunotherapy generally become less severe after the first treatment.
Throughout your treatment, your care team will provide integrative oncology services, including nutrition therapy, naturopathic medicine, pain management, oncology rehabilitation, mind-body medicine, and spiritual support. These therapies can help reduce side effects and improve your overall quality of life during immunotherapy.
Immunotherapy is basically use for Lung Cancer, Kidney Cancer.