Immunotherapy

Immunotherapy is cancer treatment that boosts your immune system so it’s better at fighting cancer. Your immune system’s job is to protect you from intruders, ranging from allergens and germs to cancer cells. It has immune cells that constantly patrol your body and destroy invaders that pose a threat.

But cancer is good at dodging your immune system’s defenses.

Immunotherapy trains your immune system to find and kill more cancer cells. It helps your body produce more cancer-fighting immune cells.

Types of immunotherapy drugs used for cancer include:

• Checkpoint inhibitors
• Adoptive cell therapy (T cell transfer therapy)
• Monoclonal antibodies
• Cancer vaccines
• Immune system modulators

Checkpoint inhibitors

Checkpoint inhibitors help immune cells called T cells fight cancer for longer.

Your T cells are powerful fighters — sometimes, too powerful. They can fight so hard that they damage healthy cells. To keep this from happening, your body has checkpoint proteins. They manage the flow of signals that tell T cells when to turn on (fight) or off (stand down). (Think of checkpoint proteins as traffic monitors that manage traffic flow by switching traffic lights off and on.) Turning T cells off keeps them from overreacting and damaging healthy cells.

But these checkpoints can also help cancer cells escape your T cells. Immunotherapy drugs stop checkpoint proteins from telling your T cells to turn off. That way, T cells keep fighting cancer.

Adoptive cell therapy (T cell transfer therapy)

Adoptive cell therapy changes your T cells in a lab. Here are the two main treatment types and what’s involved:

• CAR T-cell therapy: A provider removes T cells from your body and modifies them. The changes cause them to grow a protein called CAR that helps them fight cancer. Then, your provider puts the supercharged CAR T cells back into your body.
• Tumor-infiltrating lymphocytes (TIL): A provider removes T cells from inside your tumor and tests them to find the best cancer fighters. They make copies of those specific T cells and put the new attack force into your body.

Monoclonal antibody therapy

Monoclonal antibody therapy for cancer uses lab-made antibodies that fight cancer in many ways. Some work by blocking proteins that cancer cells need to grow. Others flag cancer cells for destruction. Some monoclonal antibodies inject toxic or radioactive material into cancer cells, killing them.

Healthcare providers also consider monoclonal antibody therapy a form of targeted therapy. This cancer treatment targets cancer cell weaknesses to stop tumors from growing.

Cancer vaccines

Cancer vaccines are different from vaccines that prevent infections. This includes vaccines that prevent cancer-related infections. For example, the HPV vaccine protects against HPV infections that cause cervical cancer. The hepatitis B vaccine prevents infection that can lead to liver cancer.

Cancer vaccines used as immunotherapy treatments don’t prevent cancer. Instead, they fight cancer you already have. They train your immune system to recognize identifying markers on cancer cells. Once immune cells identify the markers, they attack.

Immune system modulators (immunomodulators)

Immunomodulators boost your body’s immune response in many ways. There’s so much variety in how they work that they’re also called “nonspecific immunomodulating agents.” Here’s how different immunomodulators work in cancer treatment:

• Cytokines help immune cells coordinate attacks on cancer targets. They also tell your body to make more immune cells. Some cytokines send signals that cause cancer cells to die.
• Bacillus Calmette-Guérin (BCG) stimulates your immune system to fight cancer cells in your bladder. Healthcare providers use it to treat bladder cancer after surgery.
• Immunomodulatory drugs may keep tumors from developing new blood vessels. This starves cancer cells of nutrients, killing them. Some immunomodulators help your body make more immune cells.

What happens during immunotherapy?

You may receive immunotherapy alone or in combination with other cancer treatments. Treatment may happen daily, weekly, monthly or in a cycle. With cyclic immunotherapy, you take a rest period after treatment. The break gives your body time to produce healthy cells.

People receive immunotherapy for cancer in different ways. You may get:

• Intravenous immunotherapy, IV infusions that go into a vein
• Oral immunotherapy, pills you take by mouth
• Topical immunotherapy, creams you rub onto your skin
• Injection-based immunotherapy, shots that target the tumor or diseased area
• Intravesical immunotherapy, shots of BCG that go into your bladder

What are the potential benefits and risks of this treatment?

Immunotherapy can’t cure cancer. But it helps some people with cancer live longer. Oncologists often recommend immunotherapy for cancers that have spread, come back after treatment or haven’t responded to other therapies.

Unlike chemotherapy, immunotherapy doesn’t use toxic drugs that harm cancer cells, as well as healthy ones. Instead, immunotherapy uses drugs that help your own immune system target cancer cells. This can lead to less cell damage and fewer side effects. This is why immunotherapy is considered one of the most promising new types of cancer treatment available.

But immunotherapy doesn’t work on every type of cancer or for everyone who gets this treatment. And immunotherapy side effects do occur. They range from mild to severe, depending on the drug.

It’s important to work closely with your oncologist to weigh all the pros and cons before starting immunotherapy.

When should I call my healthcare provider?

Call your oncologist if you have side effects during or after treatment that are more serious than expected. You should also reach out whenever you have questions about your treatment. Questions to ask may include:

• How will I receive immunotherapy treatment?
• How long will treatment take during each session? In total?
• What short-term and long-term side effects should I know about?
• Are there newer forms of immunotherapy available to me through clinical trials?
• How will getting immunotherapy impact my outcome (prognosis)?
• How will we know if treatment is working?