What Is Immunotherapy?
Your immune system is made up of white blood cells plus the organs and tissues of your lymph system, such as your bone marrow. Other components of your immune system include certain proteins, such as antibodies that fight infections and other invaders, and cytokines that instruct your immune cells on how to respond to threats. The immune system's main job is to help your body fight off diseases and stay healthy.
Immunotherapy drugs can help boost your immune system to fight certain diseases. Several immunotherapy drugs have been approved to fight cancer, and hundreds more are being tested in clinical trials (research studies that use volunteers to test new medicines). Researchers are also studying how to target harmful immune cells while trying to protect the ones you need to stay healthy.
If your doctor suggests immunotherapy to fight cancer or any other condition, there’s a lot to talk to them about before you decide if it’s right for you.
Immunotherapy for Cancer
Immunotherapy for cancer works in two ways. Some drugs can stimulate the immune system to work more aggressively at identifying and fighting cancer cells. Other drugs, synthetic versions of various parts of your immune system, can improve how effectively your natural immune system hunts down cancer cells.
Immunotherapy vs. chemotherapy
Chemotherapy and immunotherapy are two commonly used cancer treatments, but they differ in some key ways. One of the main differences is that chemotherapy uses drugs that destroy cells, including both cancer and healthy cells. Immunotherapy doesn’t directly attack cancer cells but instead helps the body’s own immune system to more effectively identify and destroy cancer cells.
Immunotherapy for Autoimmune Diseases
Conventional autoimmune disease therapy usually involves medications that suppress the body’s overall immune system response. As a result, taking immunosuppressant drugs puts you at a higher risk for a variety of infections and illnesses.
Immunotherapy drugs instead target components of the immune system that are causing specific autoimmune conditions such as type 1 diabetes, rheumatoid arthritis (RA), multiple sclerosis (MS), and others. Immunotherapy drugs can help prevent the worsening of symptoms or progression of certain features of an autoimmune disorder.
For example, if you take immunotherapy drugs for MS, those medications won’t heal existing lesions in your nervous system, but they may help prevent new lesions from forming.
Immunotherapy for Allergies
Another area where immunotherapy is helping people boost their immune systems to stay healthy is allergy treatment. You are given gradually larger doses of allergens you're allergic to. The idea is that your immune system becomes less sensitive to the allergen over time. So, when you are exposed to the allergen in your home or any environment, your symptoms will be minor if you have any reaction at all.
Oral immunotherapy
Oral immunotherapy is used to treat food allergies. You start with a small amount of an allergen, such as peanut protein, and gradually consume more over several months. The allergens are administered at an allergist’s office or in a clinical setting so your reaction can be monitored and treatment can be provided immediately if needed.
Oral immunotherapy is not a cure but is meant to increase your resistance to a specific allergen. The goal is to make you less vulnerable to minor exposure to a particular food or ingredient.
Types of Immunotherapy
There are several different types of drugs used in immunotherapy. Certain cancer drugs may be administered once or several times over one or two years. Autoimmune drugs may require long-term use.
Among the main types of immunotherapy drugs are:
Immune checkpoint inhibitors
Checkpoints are the parts of your immune system that keep it from overreacting and harming healthy cells. But checkpoints can sometimes be too effective and can weaken the immune system response. Immune checkpoint inhibitors work by interfering with checkpoint activity, allowing the immune system to go after cancer cells.
Adoptive cell therapy (T-cell therapy)
This treatment involves the removal of T-lymphocytes, which are key cancer-fighting cells. The lymphocytes are then genetically enhanced in a laboratory and injected back into the body to more effectively fight cancer.
CAR T-cell therapy
This treatment also involves the removal of T-lymphocytes, which are then altered to make chimeric antigen receptors (CARs). These receptors enable lymphocytes to bind to cancer cells with a CAR target on their surface. CAR T-cell therapy is also being used for certain autoimmune disorders so that the enhanced lymphocytes can detect and destroy the immune cells attacking healthy tissue.
Monoclonal antibodies
Monoclonal antibodies are laboratory-made antibodies that act like your body’s natural antibodies. They are engineered for specific purposes. Cancer-fighting monoclonal antibodies go after cancer cells. For autoimmune diseases, monoclonal antibodies can interfere with inflammatory proteins, such as those that cause joint pain in rheumatoid arthritis.
Immunotherapy for allergies involves either allergy shots or sublingual (under the tongue) medications. In both cases, the immune system is activated by giving you a small amount of an allergen that should be enough to prevent symptoms or reduce their intensity.
Benefits of Immunotherapy
There are many reasons your doctor might think immunotherapy is a good choice for you:
Immunotherapy may work when other treatments don’t. Some cancers (such as certain skin cancers) may not respond well to radiation or chemotherapy but often start to go away after immunotherapy.
It can help other cancer treatments work better. Other therapies you have, such as chemotherapy, may work better when combined with immunotherapy.
Your cancer may be less likely to return. When you have immunotherapy, your immune system learns to go after cancer cells if they ever come back. This is called immunological memory, and it could help you stay cancer-free for a longer time.
Who Qualifies for Immunotherapy?
Immunotherapy is not for everyone and isn't yet an option for all types of cancer. However, the list of cancers that may be treated with immunotherapy is growing.
The factors that determine who is a candidate for cancer immunotherapy include:
- Genetic profile of the tumor
- Cancer stage (how far it has spread)
- Your response to previous cancer treatments
Researchers are still learning what types of autoimmune diseases can be treated safely and effectively with immunotherapy. It appears that having RA, MS, or type 1 diabetes may qualify you for immunotherapy. People with life-threatening autoimmune disorders or who have been treated with high levels of immunosuppressant drugs may not be good candidates.
Many factors may make you a good candidate for immunotherapy or may disqualify you, so it’s always best to talk with your health care provider about whether this treatment is right for you and what are the likely risks and benefits.
Risks of Immunotherapy
Immunotherapy holds a lot of promise as a cancer treatment, as well as a treatment for certain autoimmune diseases and allergies. Still, it can cause some problems.
You might have a bad reaction. The area where the medication goes into your body could hurt, itch, swell, turn red, or get sore.
There are side effects. Some types of immunotherapy rev up your immune system and make you feel like you have the flu, along with fever, chills, and fatigue. Others could cause problems such as swelling, weight gain from extra fluids, heart palpitations, a stuffy head, and diarrhea. Most of the time, these ease up after your first treatment.
It can harm your organs and systems. Some of these drugs can cause your immune system to attack organs such as your heart, liver, lungs, kidneys, or intestines.
It isn’t a quick fix. In some cases, immunotherapy takes longer to work than other treatments. Your cancer may not go away quickly, or you may not notice any symptom relief or change in disease progression right away.
It doesn’t work for everyone. Right now, immunotherapy works for less than half the people who try it. Many people only have a partial response. For cancer treatment, this means your tumor could stop growing or get smaller, but it doesn’t go away. For autoimmune disorders, you may not experience symptom relief or a change in the disease’s progression. Doctors aren’t sure yet why immunotherapy helps only some people.
Your body could get used to it. Over time, immunotherapy may stop having an effect on your cancer cells. This means that even if it works at first, your tumor could start to grow again.
Immunotherapy Side Effects
Like any medication or treatment, immunotherapy drugs carry a risk of side effects. Most immunotherapy side effects are mild, though serious problems can develop.
Among the more common side effects are:
- Chills
- Fatigue
- Fever
- Headache
- Muscle and joint aches
- Pain, swelling, or redness at the needle site where you received your infusion
What are the worst side effects of immunotherapy?
Though unusual, some severe side effects can develop. Among them are:
- Encephalitis (brain inflammation)
- Hepatitis (liver inflammation)
- Meningitis (brain and spinal cord inflammation)
- Myocarditis (heart inflammation)
- Pneumonitis (lung inflammation)
Why does immunotherapy cause side effects?
Immunotherapy drugs work by strengthening the immune system or by enhancing its ability to detect and attack certain cells causing your disease. However, a supercharged immune system can also go after healthy cells, triggering mild-to-severe side effects.
Signs Immunotherapy Is Working
Immunotherapy can take longer than chemotherapy and radiation treatment to show results. The main sign of effective immunotherapy treatment is a shrinking tumor or one that has stopped growing.
Other promising signs include positive changes in your blood work. Some side effects also may indicate that your immune system is doing its job.
What Is the Success Rate of Immunotherapy?
Researchers admit that it’s still hard to predict who will respond to immunotherapy and who won’t. However, even though it may be difficult to select ideal candidates for treatment, it appears that about 15-20% of cancer patients experience enduring results with immunotherapy.
Studies of responses to specific cancers also show promising results. For example, in a study on melanoma treatment, immunotherapy was linked to an average survival rate of nearly six years. Also, very few patients treated with immunotherapy who showed good early response had died within 10 years.
Results for immunotherapy treatment for autoimmune diseases are also promising but not consistent. The use of ocrelizumab for multiple sclerosis, for example, is about 98% effective in treating symptoms, while adalimumab for rheumatoid arthritis is about 60% effective.
Takeaways
Immunotherapy is an active area of research in the treatment of cancer, autoimmune disorders, and allergies. Though scientists don’t have all the answers yet, you should still discuss whether immunotherapy is right for you and your condition. You may find that it may be an option after other treatments have been tried, or it may work as a complement to other treatments suggested by your health care provider.
Immunotherapy FAQs
What is the risk of death from immunotherapy?
Research suggests that, for cancer, the risk of death associated with immunotherapy is similar to or lower than that of other standard cancer treatments.
Is immunotherapy painful?
You may experience some pain or discomfort at the site where the needle is injected to deliver medication.
