Introduction

• Immunotherapy is a type of treatment that helps the immune system fight disease; in current medical use, the term is used most commonly for cancer treatment.
• In cancer, it is considered a form of biological therapy, meaning it uses substances made from living organisms or influences biological processes to treat disease.

Basic meaning

• The immune system normally detects and destroys abnormal cells, including some cancer cells.
• But cancer cells can escape immune attack by becoming less visible to the immune system, switching off immune cells, or altering the surrounding tumor environment.
• Immunotherapy tries to overcome this problem and help the immune system act more effectively against cancer.

Main objective

• The main goal of immunotherapy is to strengthen, direct, or restore the immune response against cancer.
• Unlike chemotherapy, which mainly attacks rapidly dividing cells, immunotherapy works by changing how the body’s own defense system responds to the tumor.

How immunotherapy works

• Immunotherapy can work in different ways, such as:
  • helping immune cells recognize cancer better
  • removing “brakes” that stop immune cells from attacking tumors
  • supplying specially made immune proteins
  • modifying immune cells to fight cancer more strongly.

Major types of immunotherapy

• The National Cancer Institute lists several major types of cancer immunotherapy:
  • immune checkpoint inhibitors
  • T-cell transfer therapy
  • monoclonal antibodies
  • treatment vaccines
  • immune system modulators.

Immune checkpoint inhibitors

• These drugs block immune checkpoints, which are normal control mechanisms that prevent the immune system from becoming too active.
• By blocking these checkpoints, the drugs allow immune cells to attack cancer more strongly.
• Examples in current oncology include drugs that target PD-1, PD-L1, or CTLA-4 pathways. This is a standard classification within checkpoint therapy.

T-cell transfer therapy

• T-cell transfer therapy boosts the natural cancer-fighting ability of a person’s T cells.
• In this approach, immune cells are taken from the patient, selected or modified in the lab, multiplied, and then given back.
• It may also be called:
  • adoptive cell therapy
  • adoptive immunotherapy
  • immune cell therapy.

Monoclonal antibodies

• Monoclonal antibodies are lab-made proteins designed to bind to specific targets on cancer cells.
• Some of them mark cancer cells so the immune system can find and destroy them more easily.
• Not every monoclonal antibody is immunotherapy in the same way, but some clearly work through immune mechanisms.

Treatment vaccines

• Treatment vaccines are designed to boost the immune system’s response against cancer cells.
• They are different from preventive vaccines, which are used to stop infection or disease before it occurs.

Immune system modulators

• Immune system modulators increase the body’s immune response against cancer.
• Some act on specific parts of the immune system, while others have a broader effect.

Cancers in which it is used

• Immunotherapy drugs have been approved for many types of cancer, although they are still not used for every cancer or every patient.
• Whether immunotherapy is suitable depends on:
  • the type of cancer
  • the stage of disease
  • tumor biomarkers
  • the patient’s overall condition
  • how likely the person is to benefit versus face toxicity. This is consistent with current oncology practice and the NCI summary that not all cancers are treated with immunotherapy.

How it is given

• Immunotherapy can be given in different ways, including:
  • intravenous (IV)
  • oral
  • topical
  • intravesical.
• The exact route depends on the drug and the disease being treated.

Duration and frequency

• How often immunotherapy is given depends on:
  • the type of cancer
  • the type of immunotherapy
  • how advanced the disease is
  • how the body responds to treatment.
• Treatment may be given daily, weekly, monthly, or in cycles with rest periods.

Advantages

• A major advantage of immunotherapy is that it can produce meaningful and sometimes long-lasting responses in some cancers.
• It may also be combined with other treatments such as chemotherapy, radiation, or targeted therapy to improve outcomes in selected cases.

Limitations

• Immunotherapy does not work for everyone.
• NCI notes that only a small portion of people receiving immunotherapy may respond to certain treatments, which is why prediction of response remains a major research area.
• Some cancers are resistant from the start, while others develop resistance later.

Side effects

• Immunotherapy can cause side effects because an activated immune system may also attack healthy cells and tissues.
• Depending on the drug, side effects can affect:
  • skin
  • bowel
  • lungs
  • liver
  • hormone glands
  • other organs. This is a standard feature of immune-related toxicity in cancer immunotherapy.
• So even though immunotherapy can be very effective, it is not automatically safer than all other cancer treatments.

Monitoring

• Doctors usually monitor immunotherapy using:
  • physical examinations
  • blood tests
  • scans
  • symptom review.
• These help determine:
  • whether the tumor is shrinking or stable
  • whether the patient is developing treatment-related side effects.

Current research focus

• Current research is focused on:
  • overcoming resistance
  • predicting which patients will respond
  • understanding how tumors suppress immune responses
  • reducing side effects
  • combining immunotherapy with other treatments.

Why immunotherapy is important

• Immunotherapy is important because it has changed the treatment of several cancers and opened a new way of fighting disease by using the body’s own immune system.
• It represents one of the biggest advances in modern oncology, but it must be used selectively and under specialist supervision.

Key points to remember

• Immunotherapy helps the immune system fight cancer.
• Major types include:
  • checkpoint inhibitors
  • T-cell transfer therapy
  • monoclonal antibodies
  • treatment vaccines
  • immune system modulators.
• It does not work in every patient or every cancer.
• It can cause immune-related side effects because the immune system may also attack normal tissues.

Conclusion

• Immunotherapy is a major cancer-treatment approach that works by improving the immune system’s ability to recognize and attack cancer.
• Its significance lies in offering a different mechanism from chemotherapy or radiation, but its use requires careful patient selection, monitoring, and management of immune-related toxicity.