Immunotherapy, also called biotherapy or biologic therapy, is a type of cancer treatment that stimulates the immune system of the body to fight cancer cells.
We discuss here
- Types of immunotherapy
- How it works
- Who qualifies for it
- Types of cancers it treats
- How effective it is
- Approved immunotherapy drugs
- Its side effects
Immunotherapy makes use of substances made by the body or in a laboratory to improve how your immune system works to find and destroy cancer cells.
There are two ways by which this treatment acts:
- It stimulates the immune system to fight cancer cells by the administration of a cancer vaccine. This is called Active Immunotherapy.
It fights the cancer cells with the help of the immune system by the administration of antibodies. This is called Passive Immunotherapy.
Cancer cells do not die normally as healthy normal cells do. They divide and proliferate rapidly. You could compare it to an out-of-control Xerox machine that goes on rapidly making copies without stopping.
These abnormal cancer cells frequently mutate changing their forms, which helps them dodge the immune system. What immunotherapy does is to help the immune system locate the mutating cells and destroy them,
Ideally, cancer immunotherapy treatment should be specific to cancer cells but unfortunately, healthy cells are also targeted.
Immunotherapy is helpful in the early stages of cancer and it may be used alone or in conjunction with other cancer therapies. When used with other cancer therapies, it is called adjuvant immunotherapy. This therapy works better for some types of cancer, while it may not work well in other cases. It may be used alone by itself it may be used with other types of cancer treatments.
It is used in the treatment of cancers such as breast cancer, uterine cancer, prostate cancer, lung cancer, colorectal cancer, and more.
How does immunotherapy work?
The immune system does fight the external forces that invade our body, but it does not recognize the cancer cells as external agents because the cancer cells are our own body cells that have mutated. The immune system has to be made to recognize the cancer cells as foes, which is done through this treatment.
Who is eligible for immunotherapy?
Your eligibility for immunotherapy depends on the type of cancer you have and its stage and biomarkers detected.
A biomarker is a biological molecule found in blood, body fluids or tissues that tells of a normal or abnormal process, a condition, or disease in the body. It can tell how well the body responds to a treatment for a disease or condition.
You may be eligible for immunotherapy in the following conditions:
- The biomarkers detected by genomic testing are positive for PD-L1 expression, high microsatellite instability, or high tumor mutational burden.
- Your cancer is advanced and all options for conventional treatment are exhausted.
- You have non-small cell lung cancer that has undergone metastasis. Studies have shown that patients with advanced non-small cell lung cancer who got immunotherapy lived longer than those who didn’t get it. Such patients have been on maintenance doses of this therapy for a long period.
- Your non-metastatic cancer has been cured and the doctor may use this therapy to reduce the risk of relapse. You see this more commonly in lung cancer and melanomas.
- Immunotherapy is also used in combination with chemotherapy to treat certain cancers.
What types of cancer can be treated with immunotherapy?
Presently, immunotherapy is not approved to treat all types of cancer.
The U.S. Food and Drug Administration first approved immunotherapy for the treatment of melanoma and non-small cell lung cancer.
Other types of cancer that may be treated with immunotherapy include:
- Stomach cancer
- Liver cancer
- Cervical cancer
- Breast cancer
- Bladder cancer
- Brain cancer
What stage of cancer does immunotherapy treat?
Immunotherapy has shown promising results in the treatment of advanced lung cancer, either alone or in combination with other treatments like chemotherapy or surgery.
It is is also an option to treat children and adults with Hodgkin and non-Hodgkin lymphoma. It is also used to treat stage 3 or stage 4 lung cancer, advanced non-small cell, and small cell lung cancer.
How effective is immunotherapy for cancer?
Immunotherapy has been successful to treat different types of cancer including lung cancer, head and neck cancer, bladder cancer, kidney cancer, and Hodgkin lymphoma.
Otherwise, the results are mixed: they have better results in some cancer cases, produced miracles in some, but have failed to work in all indicated cases.
Cancer immunotherapy also offers the prospect of long-term remission in some cancer cases.
It can make the immune system remember cancer cells once it has started identifying them. This is called “immune memory” and offers longer-lasting remissions.
Clinical studies on long-term survival (the period from the date of diagnosis or the start of treatment) have shown that the benefits of immunotherapy are long-lasting and can remain even after treatment is completed.
Generally, the response rates are about 15 to 20%. This refers to the percentage of patients whose cancer shrunk or disappeared after taking this therapy.
Types of Immunotherapy
There are currently five different classes of immunotherapies that indicate the ways by which immunotherapy enhances the cancer-fighting activity of the immune system.
Adoptive Cell Therapy
Adoptive cell therapy or cell-based immunotherapy physically infuses and supplements the patient’s immune system with his own immune cells that have been reactivated, strengthened with cancer-fighting properties, and expanded in numbers. These include bone marrow transplants and newer cell transplants, such as CAR T cells.
Vaccines educate and stimulate the immune system against a possible risk.
Preventive vaccines can protect you against cancer whereas therapeutic vaccines can stimulate the immune system to act against the existing cancer.
Immunomodulators act on the pathways that control the immune system’s activity. They modulate the acceleration and slowing down of the immune system. They improve the immune system’s capability to attack and eliminate cancer. They can be broadly divided into four categories: checkpoint inhibitors, cytokines, agonists, and adjuvants.
Antibody based targeted therapy
This therapy targets the cancer cells directly, disrupts their activity and stimulates the immune system to attack them.
Oncolytic virus therapy
Oncolytic virus therapy uses viruses that have been modified to attack the cancer cells directly.
Common immunotherapy drugs classified as checkpoint inhibitors include:
- Ipilimumab (Yervoy)
- Pembrolizumab (Keytruda)
- Nivolumab (Opdivo)
- Atezolizumab (Tecentriq)
Common cytokines used in cancer therapy include:
- Interleukin-2 (IL-2)
- Interferons-alpha (IFN-alpha)
Research continues to develop new immunotherapy drugs.
What are immunotherapy side effects?
Immunotherapy may cause a several side effects many of which are flu-like symptoms. They include:
- Fatigue and weakness
- Nausea and vomiting
- Mouth sores
- Increased blood pressure
- Pedal edema
- Fever or chills
- Skin rashes or itching
The side effects usually subside after the first treatment. Doctors offer nutritional support, pain medication, rehabilitation and spiritual support throughout the treatment to manage your side effects.