What Are Cancer Immunotherapy Clinical Trials?

Medically Reviewed by Jennifer Robinson, MD on January 21, 2021

Immunotherapy is a somewhat new treatment that helps your immune system find and destroy cancer cells. Several immunotherapy drugs are approved for cancer, and hundreds more are available to those who take part in clinical trials. For many people, joining a clinical trial is the best treatment.

In clinical trials, doctors use new medications or therapies on small groups of volunteers to see how well they work. They’re the last step in the research process before a drug or treatment can be approved.

You don’t need to live in a big city to take part in a cancer clinical trial. They happen across the United States and around the world. Your doctor may not mention them to you, so be sure to ask about clinical trials at your next appointment. They can help you weigh the pros and cons and find out if there’s an immunotherapy clinical trial near you.

Pros and Cons

There are many reasons to consider taking part in a clinical trial:

  • You may get it along with other treatments to boost your odds of beating cancer.
  • It has cured some cancers.
  • You have access to a medicine that isn’t available to the public.
  • You could help scientists learn more about cancer so they can help more people in the future.

Like all medicine, immunotherapy comes with risks. A few to think about before you join a clinical trial:

  • The treatment may not work.
  • There may be unexpected side effects.
  • You may need tests that could be uncomfortable or take a lot of time.
  • Your health insurance may not cover some costs.

Phases of Clinical Trials

There are several phases of clinical trials for immunotherapy and other drugs:


Phase I trials. These are small, with about 15-30 people. The goal is to:

  • Find a safe dose of the drug
  • Decide how the drug should be given (shots, pills, etc.)
  • Find out how the drug affects the body and how well it fights cancer 

Phase II trials. These are larger than phase I trials, but they still have fewer than 100 people. The purpose is to:

  • Learn if the drug works on a certain type of cancer
  • See how the drug affects the body and how well it fights cancer 

Phase III trials. These trials have anywhere from 100 to thousands of people, and they compare a drug to the standard treatment. Scientists may test a new drug or a new use for an approved immunotherapy. 

Other clinical trial phases. There are also phase 0 and phase IV. Phase 0 trials are tiny and help scientists decide whether to use a drug in phase I. Phase IV trials happen after a drug has been approved and take a look at its long-term effects.

Who Pays for Clinical Trials?

Health plans often cover routine care when you’re part of a clinical trial. This can include:

  • Doctor visits
  • Hospital stays
  • Standard cancer treatments
  • Treatments for side effects
  • Treatments to ease cancer symptoms, like pain
  • Lab tests
  • X-rays, MRIs, etc.


But insurance usually doesn’t cover some costs, like the immunotherapy drug being tested, plus any tests and scans done only for research. The trial's sponsor may cover these research costs. The best way to find out what your health plan will cover is to check with your health insurance company. Your doctor or a member of the clinical trials research team may be able to do this for you.

Questions to Ask

If you’re thinking about joining an immunotherapy clinical trial, you probably have many questions for your doctor or the research team. Make sure these are on your list.

  • Who will be in charge of my care while I’m in the trial?
  • How do I know if the treatment is working?
  • How can it help me?
  • What happens if I decide to leave the trial?
  • Will I have to pay for any of the treatments or tests?
  • How often will I have to come in for treatment or tests?
  • What are my other treatment choices?
WebMD Medical Reference



Cancer Research Institute: “About Clinical Trials,” “Should You Participate?” 

National Cancer Institute: "Deciding to Take Part in a Clinical Trial,” "Insurance Coverage and Clinical Trials,” “Paying for Clinical Trials,” "Phases of Clinical Trials,” "Questions to Ask Your Doctor about Treatment Clinical Trials," “What Are Clinical Trials?” “Where Trials Take Place.”

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