What is the Difference Between Immunotherapy and Targeted Therapy

The key difference between immunotherapy and targeted therapy is that immunotherapy stimulates a host response using the immune system, while targeted therapy aims to inhibit molecular pathways by targeting proteins.

The immune system helps the body fight against infections and diseases. It is made up of mainly white blood cells, tissues, and organs of the lymphatic system. The immune system identifies and destroys abnormal cells in the body to prevent the growth of cancers. Immunotherapy and targeted therapy are two types of cancer treatments associated with the immune system. Immunotherapy is directly associated with the immune system for cancer cell destruction. Targeted therapy inhibits molecular pathways that influence cancer cell growth.

CONTENTS

1. Overview and Key Difference
2. What is Immunotherapy  
3. What is Targeted Therapy
4. Similarities – Immunotherapy and Targeted Therapy
5. Immunotherapy vs Targeted Therapy in Tabular Form
6. Summary – Immunotherapy vs Targeted Therapy

What is Immunotherapy?

Immunotherapy is a type of cancer treatment that helps the immune system to fight cancer. However, it is not used as chemotherapy, radiation therapy, or surgery. There are different ways of giving immunotherapy, and they are intravenous (IV), oral, topical, and intravesical. There are several types of immunotherapies to treat cancer patients. They are immune checkpoint inhibitors, T-cell transfer therapy, monoclonal antibodies, treatment vaccines, and immune system modulators.

Immune checkpoint inhibitors are drugs that block the immune checkpoints. Such treatments allow immune cells to respond faster and more strongly to cancer. T-cell transfer therapy boosts the natural ability of T-cells against cancer cells. During this treatment, the immune cells are obtained from the tumours that are active against cancer and changed to attack the cancer cells more efficiently. This is done in laboratories, and they grow in large batches and are inserted into the body via a needle into a vein. T-cell transfer therapy is also known as adoptive cell therapy, adoptive immunotherapy, or immune cell therapy. Monoclonal antibodies are proteins created in laboratories to bind to specific target sites on cancer cells. They are also known as therapeutic antibodies. Treatment vaccines act against cancer by boosting the response of the immune system to cancer cells. Immune system modulators are agents that enhance the immune responses in the body against cancer.

Immunotherapy causes side effects since therapies also act against healthy cells and tissues. Common side effects are swelling, pain, soreness, itchiness, rashes, and redness around the skin where the needle is used. It also causes flu-like symptoms and heart palpitations, diarrhoea, organ inflammation, infections, and sinus congestion.

What is Targeted Therapy?

Targeted therapy is a type of cancer treatment that target proteins that control the growth, division, and spreading of cancer cells. Most types of targeted therapies are small-molecule drugs or monoclonal antibodies. Small molecule drugs are small, and this enables them to enter cells faster and more efficiently. Therefore, they are used for targets inside cells. Monoclonal antibodies are proteins that are produced in laboratories. These proteins attach to specific targets found in cancer cells. Some monoclonal antibodies mark cancer cells for clear visibility, which makes it easier to destroy cancer cells by the immune system. Other monoclonal antibodies stop cancer cells directly from growing or causing self-destruction. Monoclonal antibodies are also called therapeutic antibodies. Testing cancer for targets helps to choose the required treatment, and it is known as biomarker testing.

Targeted therapy helps the immune system destroy cancer cells. It stops the growth of cancer cells by interrupting signals that cause their growth and division without order. It also stops signals that help form blood vessels. Moreover, it helps to deliver cell-killing substances to cancer cells, starve cancer cells of the hormones required for growth, and cause cancer cell death. However, a major drawback of this treatment is that cancer cells become resistant to targeted therapy. The most common side effects of this therapy include diarrhoea and liver problems, and other side effects include delay in blood clotting in wound healing, high blood pressure, mouth sores, fatigue, nail changes, loss of hair colour, and skin problems.

What are the Similarities Between Immunotherapy and Targeted Therapy?

• Immunotherapy and targeted therapy are cancer treatments.
• They help the immune system fight against cancer.
• Both therapies have monoclonal antibodies as treatments.
• They destroy cancer cells.
• Moreover, both therapies are administered intravenously.

What is the Difference Between Immunotherapy and Targeted Therapy?

Immunotherapy stimulates a host response using the immune system, while targeted therapy inhibits molecular pathways by targeting proteins. Thus, this is the key difference between immunotherapy and targeted therapy. Immunotherapy is tailored and expensive, while targeted therapy develops resistance to cancer cells. This is the main difference between immunotherapy and targeted therapy in terms of their limitations. Furthermore, the main side effects of immunotherapy are autoimmune effects, and the side effects of targeted therapy are liver problems and diarrhoea.

The below infographic presents the differences between immunotherapy and targeted therapy in tabular form for side by side comparison.

Summary – Immunotherapy vs Targeted Therapy

Immunotherapy and targeted therapy are two types of cancer treatments. Immunotherapy stimulates a host response using the immune system, while targeted therapy aims to inhibit molecular pathways by targeting proteins. There are several types of immunotherapies; they are immune checkpoint inhibitors, T-cell transfer therapy, monoclonal antibodies, treatment vaccines, and immune system modulators. Types of targeted therapies are small molecule drugs or monoclonal antibodies. So, this summarizes the difference between immunotherapy and targeted therapy.

Reference:

1. “Immunotherapy for Cancer.” National Cancer Institute.
2. “Targeted Therapy for Cancer.” National Cancer Institute.

Image Courtesy:

1. “11 Hegasy CTLA4 PD1 Immunotherapy” By Guido4 – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Targeted Therapy” By Simon Caulton – Own work (CC BY-SA 4.0) via Commons Wikimedia