What is a clinical trial?

A clinical trial is a research study that looks at how well a new treatment works in people. This is called “efficacy.” The treatment may be a drug, medical procedure, medical device, or even a lifestyle change. Trials are designed to answer specific questions about the safety and effectiveness of new drugs, procedures, surgical techniques, or medical devices. A clinical trial also makes sure the new treatment is safe, well tolerated, and does not cause harm or serious side effects in most people.

Clinical trials are the primary tools for us to better understand kidney cancer and what may or may not work to prevent it, treat it, or manage its symptoms and side effects – they seek to answer research questions no one knows the answer to yet. Because of this, there is a degree of uncertainty when it comes to participating in a clinical trial. It’s important for potential participants to thoroughly understand the risks and benefits involved.

Clinical trials involve patient participants. Clinical trial participation is voluntary and participants may withdraw from trials at any time for any reason. Participating in a clinical trial does not guarantee a desired result or outcome but the findings add to the medical knowledge about kidney cancer and its treatment and can help improve and prolong the lives of future patients.

For example, a clinical trial may look at whether a new exercise routine helps people lose weight. Or it may look at whether a new drug helps lower blood pressure in people with high blood pressure.

In short, a clinical trial helps to answer two important questions:

  • Does the new treatment work in humans? If so, how well does it work? Is it better or the same as treatments that are currently available? If it is the same, does it have fewer side effects than other treatments? Does it help people who have not responded to other treatments?
  • Is the new treatment safe? No treatment is completely safe for everyone; however, a clinical trial helps make sure the benefits outweigh the possible risks for most people.

Who conducts clinical trials?

Each clinical trial is led by a principal investigator, who is usually a medical doctor. In addition, there is often a team of doctors, nurses, social workers, and other health professionals who will work directly with you and provide your medical care. To cover the costs involved, a study must also have financial support (funding). This funding may come from a drug company (pharmaceutical), university medical center, government agency, or other organization. The group that provides funding is usually referred to as the “sponsor.”

What is a study protocol?

Clinical studies in the United States are regulated by a government agency called the “Food and Drug Administration (FDA).” Each study is reviewed, approved, and watched over by the FDA. Before a clinical trial can begin, it must receive approval from the FDA. It must also have an action plan (called a “protocal”). The action plan describes what will be done in the study, how it will be conducted, and why each part of the study is needed. This helps make sure the study will answer certain questions about the treatment while trying to make sure the people taking part are kept as safe as possible. Among other things, a protocol describes:

  • The reason for conducting the study
  • Who may participate (“eligibility”)
  • How many participants are needed
  • What tests and procedures will be done during the study and how often
  • Information about the drugs that will be used, including the name and dosage
  • The phase of the study (phase I – phase IV)
  • How long the study will last

Actual study protocols can be very long (over 100 pages) and very technical. They are not written with patients in mind, so they can be hard for most patients to understand. Clinical trials must also have guidelines about who can be in them, and this information can be helpful if you are trying to decide whether you want to participate.

Why are clinical trials needed?

Clinical trials try to find better ways to prevent, screen for, diagnose, or treat diseases and other health problems. Without them, we would not have new treatments or other advances in health and medicine.

Types of Clinical Trials

Clinical trials fall into one of several categories:

Phase I

Phase I trials are the initial studies of drugs or treatments designed to establish the safest dose, decide how the new treatment should be given, and see how the body and the cancer cells are affected.

Phase II

Phase II trials determine if the new treatment is effective against a particular type of cancer and continue to monitor how the body is affected by the treatment.

Phase III

Phase III trials compare a new treatment or new use of a treatment with the current standard treatment.

Since clinical trials are designed to answer specific research questions, there are typically specific criteria that determine who may participate. These criteria are set by the trial’s study sponsor and can include age, type of cancer, stage, tumor histology, and treatment history, for example.

Who can participate in a clinical trial?

Each study has its own rules about who can — or cannot — participate. This is called “eligibility.” Your eligibility may be based on your age, gender, overall health, type and stage of a disease, treatment history, and other conditions.

Not everyone is chosen to participate. You may be turned down simply because you do not have certain characteristics, such your gender or age.Things that allow you to participate are called “inclusion criteria,” and things that disqualify you are called “exclusion criteria.”

People who participate in clinical trials do so freely and of their own will. They are volunteers. In many studies, the volunteers will have a common health condition, such as kidney disease, high blood pressure, or diabetes.

What is “Informed Consent?”

Before you can participate in a trial, the researchers must make sure you understand all the possible risks, benefits, and alternatives to the study. As part of this process, you may be given verbal instructions, printed materials to read, questionnaires, and other forms of information. If you have any unanswered questions about the trial, be sure to ask.

At the end of this process—and if you are still willing to participate—you will be asked sign a document stating that you understand the risks, benefits, and alternatives. This is called “informed consent.” Remember, the “informed consent” document is not a contract. It is meant to protect you, not bind you. You can withdraw from the study at any time, for any reason, even if the study is not over.

Should I participate in a clinical trial?

You are the best judge and the only person who can answer this question. Participating is not without risks, but it may give you an opportunity to improve your own health. For example, you may have access to a treatment that’s not otherwise available. Or the new treatment might be safer or work better than current treatment options. Some people who have participated in clinical trials believe they receive more attention from the healthcare staff, and more careful monitoring of their condition and possible side effects of treatment. You may even have all or part of your medical care and other expenses paid for by the study sponsors. Also, you may be helping future generations that experience kidney problems.

But there are also some possible downsides to consider. The new treatment may have unknown side effects or risks, or it may not work for you even if it helps others. You may find some of the requirements inconvenient, such as traveling a long distance for appointments, frequent office visits and tests, or long time commitments.

One thing to ask yourself is whether the potential health benefits will outweigh the possible risks. You should learn as much as you can about the study and feel comfortable asking the research team questions. Be sure to ask who covers the costs and other expenses, such as travel. Tell your own healthcare provider that you are considering a trial, and discuss the advantages and disadvantages together.

Randomized Clinical Trials

Randomized trials are when patients are directed into one of two or more treatment categories using a random selection technique to ensure the validity of the trial results. Participants in phase III trials and occasionally phase II trials are typically randomized to compare two or more treatments and may include a placebo group.

Placebo Group

In a clinical trial, a placebo is an inactive product that resembles the product being tested but it has no treatment effect. Placebos are an efficient way to demonstrate the effectiveness of a new treatment. Trial participants are told if there is a placebo group as part of the trial design, but they may not know whether they will be part of an active treatment group or the placebo group. Phase II and III trials might include a placebo group if there is no standard treatment against which to compare a new drug.


Blinded, or masked, trials are designed to prevent the research team and the participants from influencing the study results and reducing bias by withholding some information. In a blinded trial, the research team knows which participants are getting which treatment, but participants do not know. In a double-blind trial, neither the research team nor the participants knows who is receiving which treatment.


Some of the benefits of participating in a clinical trial are:

    Access to new treatments that may be more effective than what is currently approved by the FDA/EMA Receiving investigational treatments at no cost.
  • Contributing to medical progress


Some of the risks of participating in a clinical trial are:

  • Uncertain treatment outcomes
  • Side effects from an experimental treatment
  • More procedures such as blood tests or biopsies
  • More time and expense, especially in cases where trial funding may not cover all expenses
Find NCI-Supported Clinical Trials

NCI-supported clinical trials are those sponsored or otherwise financially supported by NCI. See NCI’s guide, Steps to Find a Clinical Trial, to learn about options for finding trials not included in NCI's collection.


Search Tip: For more search options, use NCI’s advanced search.

Finding a Trial

Asking your healthcare team about clinical trials is a good way to begin gathering information about what clinical trials are and whether there are ongoing clinical trials that might be right for you.

The most comprehensive database of clinical trials conducted around the world is available at www.ClinicalTrials.gov. This searchable database includes information about a trial’s purpose, who may participate, where the trial locations are, and who to contact for further details about the trial and eligibility criteria.

Patients/caregivers may contact the KCA Patient Navigator Program for help navigating ClinicalTrials.gov and finding a suitable clinical trial. Your health care provider can help you evaluate trials and eligibility.

Questions to Ask Your Doctor about Treatment Clinical Trials

If you are thinking about taking part in a clinical trial, be sure to ask your doctor, “Is there a clinical trial that I can join?” If your doctor offers you a trial, here are some questions you may want to ask.

Questions about the Trial

  • What is the purpose of the trial?
  • Why do the researchers believe that the treatment being studied may be better than the one being used now? Why may it not be better?
  • How long will I be in the trial?
  • What kinds of tests and treatments are involved?
  • How will the doctor know if the treatment is working?
  • How will I be told about the trial’s results?
  • How long do I have to make up my mind about joining this trial?
  • Who can I speak with about questions I have during and after the trial?
  • Who will be in charge of my care?
  • Is there someone I can talk to who has been in the trial?

Questions about Risks and Benefits

  • What are the possible side effects or risks of the new treatment?
  • What are the possible benefits?
  • How do the possible risks and benefits of this trial compare to those of the standard treatment?

Questions about Your Rights

  • How will my health information be kept private?
  • What happens if I decide to leave the trial?

Questions about Costs

  • Will I have to pay for any of the treatments or tests?
  • What costs will my health insurance cover?
  • Who pays if I’m injured in the trial?
  • Who can help answer any questions from my insurance company?

Questions about Daily Life

  • How could the trial affect my daily life?
  • How often will I have to come to the hospital or clinic?
  • Will I have to stay in the hospital during the clinical trial? If so, how often and for how long?
  • Will I have to travel long distances?
  • Will I have check-ups after the trial?

Questions about Comparing Choices

  • What are my other treatment choices, including standard treatments?
  • How does the treatment I would receive in this trial compare with the other treatment choices?
  • What will happen to my cancer without treatment?


  • NIH Clinical Research Trials and You
  • Clinical Trials Information, National Cancer Institute
  • Learn about clinical studies, clinicaltrials.gov
  • Find NCI-Supported Clinical Trials
  • ClinicalTrials.gov