Patient Guide to Clinical Trials

Clinical Trials — Providing New Hope For Our Patients Every Day

Fred Hutchinson Cancer Center has one of the most active clinical trial programs in the world. Through clinical trials, our patients gain access to promising new treatments. Every advance in cancer treatment has resulted from clinical trials. For example, bone marrow transplantation, which is considered the most important advance in cancer treatment of the last quarter century started right here.

Today’s clinical trials turn cancer research into real-world treatments and cures.

How Does Fred Hutch Research Benefit Me?

It’s always up to you whether to take part in a clinical trial. One potential benefit is that you may be among the first to get access to a promising new treatment. Even if you decide not to participate, the fact that Fred Hutch provides treatment for patients in trials is a good reason to come here for your care.

Because of our commitment to developing advances in treatment and our reputation as a hub for research, we attract the best and most experienced doctors, who can offer you access to the latest treatment options. We also attract patients who are more likely to be savvy health care consumers: patients who are interested in treatment options beyond those offered in the community setting and who expect — and receive — a high standard of care.

Fred Hutch and UW Medicine form the only National Cancer Institute-designated Comprehensive Cancer Center in Washington state.

Following the merger of long-time partners, Fred Hutchinson Cancer Research Center and Seattle Cancer Care Alliance, the organization was renamed to Fred Hutchinson Cancer Center. We are an independent, nonprofit organization that also serves as UW Medicine's cancer program. 

Why Do Clinical Trials Matter?

Clinical trials are essential to disease research and are a key component of Fred Hutch’s mission to translate scientific discoveries into prevention, diagnosis, treatment and cure for cancer and all the conditions we treat. Without clinical trials, new interventions could not be approved.

Every advance in cancer treatment in recent years has come out of clinical trials. Take just one important example: Bone marrow transplantation, among the most significant medical advances of the 20th century, was developed by researchers at Fred Hutch. Now used to treat many kinds of cancers and noncancerous blood disorders, this life-saving treatment would not exist without patients who were willing to participate in clinical trials.

Who Are Clinical Trials For?

The goal of clinical studies is to increase our knowledge about diseases and to develop safer, more effective treatments in the fight against them. Cancer is complex, and there are clinical trials that look at many aspects and stages of the disease — trials are not just for patients in the final stages of their illness. There are trials:

  • To examine ways to prevent cancer in healthy people
  • To better detect and diagnose cancer
  • For patients starting initial treatment and for patients who relapse
  • To assess the quality of life of cancer patients and survivors

What Do Clinical Trials Test?

Many clinical trials test new interventions or new combinations of interventions in people, sometimes referred to as human subjects or study participants. New interventions include:

  • Medical products, such as drugs and devices
  • Procedures, such as surgery and radiation therapy techniques
  • Behavior changes, such as diet and exercise

Some clinical trials focus on the long-term effects of treatments already in use.

Before reaching clinical trials, a new intervention typically will have been studied in the laboratory (nonclinical studies) and in animals (pre-clinical studies). Clinical trials are carefully designed to answer questions about the safety and effectiveness of the intervention in people. Clinical trial participants are closely monitored throughout the study.

Clinical Trial Types

There are several types of clinical studies (also called clinical trials), including treatment studies, quality-of-life studies, detection and diagnostic studies, prevention studies, and correlative studies.


A large number of clinical studies offered at Fred Hutch are treatment studies. These studies attempt to find better ways to treat people with cancer or other diseases, and they are available for all stages of disease, from early to advanced.

The studies test new treatments or new ways of using current treatments, including drugs (such as chemotherapy agents, vaccines, blood products, or gene therapies), medical devices (such as infusion pumps), techniques for surgery or radiation therapy, or a combination of treatments, as well as no treatment or delayed treatment.


These studies typically explore and measure ways to use supportive care to improve the comfort and quality of life of patients and survivors. This may include ways to manage disease symptoms or ways to manage or decrease side effects associated with treatment. These studies may be:

  • Agent studies, in which the participant takes something—for example, a drug to improve mouth sores or lessen nausea
  • Action studies, in which the participant does something—such as begins an exercise regimen or makes dietary changes

Some studies are even designed to help families and caregivers cope with their needs. For example, a study might test whether spouses of women with breast cancer have less depression and anxiety and better communication with their spouse if they participate in an educational counseling program.

Detection and Diagnostic

Detection and diagnostic studies test new ways of finding and identifying cancer or another disease early or with better accuracy. When cancer is found early, it may be easier to treat, and there may be a better chance for a cure.

  • Detection studies usually involve screening healthy volunteers who do not have any signs or symptoms of the disease being studied. Often these studies enroll participants who have a higher risk of developing the disease; for cancer, this may mean they are at higher risk as a result of their family history (genetics) or exposure to cancer-causing substances (carcinogens).
  • Diagnostic studies usually are trying to improve the accuracy of diagnosing a disease in people who have some signs or symptoms.


In cancer research, the goal of a prevention study is to find ways to prevent people from getting cancer in the first place or to prevent a recurrence or new cancer in people who have had the disease. In these studies, volunteers who don’t have cancer may be recruited to participate, often because they are at high risk, due either to genetics or to exposure to carcinogens. Participants may take something, such as a drug, or do something, such as change their diet, to lower their risk.

Most prevention studies compare groups of people while the study is underway, rather than waiting until the end of the study, to see if there is a difference. If there is a distinct benefit or risk to a particular group, the study will be stopped or changed so everyone receives the best option.


In addition to testing the safety and effectiveness of new interventions, clinical studies provide the opportunity for researchers to do correlative studies. These studies look for relationships between factors. The idea is that noticing trends and investigating them might improve doctors’ knowledge about how to prevent, detect, and treat a disease.

Correlative studies may use specimens from study participants, including their blood, tumor cells, or other tissue. Researchers must obtain permission from participants before using their specimens—which may have been taken before, during, or after treatment—for research purposes.

An example of a correlative study is one that compares biomarkers in a patient’s feces and blood to their colonoscopy results to see whether the biomarkers may be as accurate as a colonoscopy for detecting colon cancer early.

Clinical Trial Phases

Clinical studies, which test interventions in people, occur in several steps, known as phases. While each phase is designed to answer different research questions, studies in all phases evaluate the safety of the intervention.

Typically, there are four phases of clinical studies:

  • Phase I: Safety
  • Phase II: Efficacy
  • Phase III: Comparison
  • Phase IV: Post-Marketing

If a new treatment (also called an investigational or experimental treatment) is successful in one phase, it may move on to the next phase. The information gained in each phase helps researchers design subsequent studies. As a treatment progresses through the phases, the number of participants in the studies typically increases. For example, a Phase I study will have a small number of participants, perhaps as few as 10, while a Phase III study may enroll hundreds or even thousands of people.

Sometimes two phases may be combined (as in Phase I/II or Phase II/III studies) to provide a smooth transition between phases and allow the research questions to be answered more quickly or with fewer participants.

Although treatment studies are typically assigned a phase, other types of clinical trials, such as prevention studies, may not be labeled this way.

Phase I is typically the first time the treatment is tested in humans, the first time it is studied for a particular condition, or the first time it is being administered in a particular way (for example, in a new combination with other drugs).

Even though the investigational treatment has been studied in the laboratory (nonclinical studies) and in animals (pre-clinical studies), the risk to participants can be significant. For this reason, Phase I studies often enroll small numbers of participants (about 15 to 30) who typically don’t have any other treatment options—patients who cannot be treated with the standard (most widely accepted) treatment or for whom there is no standard treatment. In cancer research, these tend to be patients with advanced disease.

Phase I studies evaluate the safety of a new treatment, including side effects, dose, and impact on the body. For a new drug, Phase I studies are designed to find the safe dose amount and schedule as well as the best way to give the drug, such as orally or by injection. To determine the highest dose that can be safely given (maximum tolerated dose), researchers may start by giving a low dose to a small group of participants, a slightly larger dose to the next group, and so on, while closely monitoring the participants for side effects.

Generally, the study is only intended to determine the safety of the new treatment, not to show whether it is effective; however, results may provide an indication of whether it is effective.

Learn About the Phase I Program

Phase II studies are done to determine if a treatment is effective for a certain condition. In the case of cancer, researchers look at the response to the treatment in participants who have the same cancer or similar types of cancer. In Phase II studies, participants are usually given the treatment in whatever way (dose, schedule, method of administration, and so on) researchers determined was best during Phase I studies; sometimes Phase II studies test variations in dose or schedule.

Phase II studies often include more participants than Phase I studies but are usually limited to fewer than 100 people.

Phase III studies compare the effectiveness and side effects of treatments, typically a new treatment and the standard treatment, in patients with a particular type of cancer. The goal is to determine whether the investigational treatment is more effective than the standard.

To make this comparison, patients may be randomized—that is, randomly assigned to one of the two (or sometimes more) arms of the study. Neither you nor your doctor can choose or influence the arm (or group) you will be in.

  • If you are assigned to the investigational group, you will get the new treatment being tested.
  • If you are assigned to the control group, you will get the standard treatment for your cancer.

Randomization, used in some Phase II and nearly all Phase III studies, is important to the scientific validity of the research. It eliminates bias in selecting which patients get which treatment. This helps ensure that differences between the groups’ results are due to the different treatments they received and not other factors. Often, randomized studies are single blind, meaning you don’t know which treatment you are getting, or double blind, meaning neither you nor your doctor knows.

Phase III studies enroll a large number of participants—typically between 100 and several thousand—and often take place at a number of cancer centers throughout the country (which is why they may be called multicenter studies).

In the United States, after successful Phase III clinical studies, the developer of the treatment (such as a pharmaceutical company in the case of a drug) may apply for U.S. Food and Drug Administration (FDA) approval of the treatment. If the FDA approves the treatment, it may become a standard therapy.

Some treatments that are approved by the FDA are tested in Phase IV clinical studies. In these studies, also known as post-marketing studies, researchers may monitor the effectiveness and safety of the treatment over a long period of time and in a larger, more diverse, or different population than in previous studies.

In cancer research, placebos, which are inactive treatments, may be given to the control group in randomized studies to test interventions that might prevent cancer in people who do not have the disease. Placebos are almost never used in cancer treatment studies. They might be used in these situations:

  • If no standard treatment exists for the study participants, researchers might compare the effects of a new treatment with the effects of a placebo. This helps them distinguish between the actual benefits of the investigational treatment and the benefits of believing you’re getting effective treatment.
  • More often a placebo is given along with a standard treatment so researchers can compare this with an investigational treatment plus the same standard treatment.

You will be told in advance if the study you’re considering uses a placebo and you could be assigned to the placebo group.

Safety of Clinical Trial Participants

Patient safety is extremely important to us at Fred Hutch. We do everything we can to protect you against unnecessary risks during your treatment, whether you are in a clinical study or not. At the same time, we recognize that no clinical study is without some degree of risk, and we have a number of safety procedures and practices in place.

State, national, and international regulations and policies protect the rights, safety, and well-being of people who are enrolled in clinical studies, also called clinical trials, and ensure the studies are conducted according to strict scientific and ethical principles. In the United States, the Office of Human Research Protections oversees clinical studies and protects study participants. The U.S. Food and Drug Administration (FDA) has authority over clinical studies of drugs, biologics, and medical devices.

Your rights and safety are protected through the clinical study protocol, which undergoes scientific and human subjects–protection reviews and approval, as well as through ongoing monitoring of safety throughout the study.

All clinical studies follow a plan (protocol) that includes:

  • The reason for doing the study
  • Rules about who can join the study (eligibility, or inclusion and exclusion, criteria)
  • The number of people needed for the study
  • Details of the treatment and safety information
  • Schedule and details of tests and evaluations that will be done
  • Details about information that will be collected from study participants

Eligibility criteria may include many factors, such as a certain type and stage of cancer, previous treatment history, age, gender, medical history, and current health status. Eligibility criteria help protect people from getting treatment that may harm them; these criteria also reduce differences among study participants, which helps ensure that study results are due to the intervention provided rather than other factors.

At Fred Hutch, study protocols go through internal scientific review, safety review, and clinical review prior to being submitted for review by an institutional review board (IRB), a human subjects–protection entity. IRB review is a federal requirement of all clinical studies: No participants may be enrolled in a clinical study until the protocol has been approved by an IRB.

The IRB is made up of researchers (doctors, nurses, and scientists) and laypeople and is responsible for making sure the rights and welfare of human subjects are protected in studies. The IRB also evaluates proposed studies for ethical research practices, proper attention to safety of participants, and respect for participants’ rights.

It is up to you whether to participate in a clinical study. The informed consent process—giving people enough information about the purpose, plan, treatment, tests, procedures, duration, risks, benefits, and alternatives of a study to allow them to make an informed decision—is important to participant safety. Your doctor or nurse should explain the study to you in detail in terms you can understand and answer any questions you may have about the study.

There are special procedures in place to provide informed consent for non-English speaking participants so they too can consider taking part in clinical studies. Learn more about interpreter services and other resources for international patients.

Feel free to ask questions and discuss the study with family and friends so you can make a decision you are comfortable with. If you decide to participate in the study, you will be asked to sign an informed consent form. You must sign the form to enroll in the study before you undergo any procedures that are part of the study.

During the study, researchers must inform you of any new risks, benefits, or side effects they discover.

You can decide to stop participating in the study after signing the informed consent form or at any time during the study. Also, your treatment team may decide before or during the study that it’s not in your best interest to begin or continue in the study—for example, if there’s an unexpected change in your health.

Discuss your decision about participating in or withdrawing from a clinical study with your treatment team. They can tell you how your decision may affect your health and discuss other treatment options with you. Your relationship with your Fred Hutch treatment team and the quality of care provided will not change based on whether you join or stay in a clinical study.

The IRB that approved the study continues to monitor the study while it is in process. This includes conducting reviews of the study at least once a year, reviewing any changes to the study protocol or the informed consent form during the study, and reviewing any new information about the study.

In addition, for some clinical studies—usually Phase III studies—a data and safety monitoring board (DSMB) monitors and reviews the study data periodically to ensure the safety of study participants. The DSMB is an independent committee made up of statisticians and doctors who are experts in clinical research. A study may be stopped early if safety concerns arise or if the answer to the main research question has been answered by the study.

The FDA also may inspect study records and sites to make sure participants are protected and studies are being done correctly.

Some populations, such as children, prisoners, and other groups that may be vulnerable to influence, have additional safeguards to protect them. For example, since children often cannot understand study details, they cannot give true informed consent. Instead, their parents or guardians must give permission for them to participate. 

Older Adults and Children

Older people have different levels of health and independence and different expectations of treatment — age need not be a major factor in determining their treatment options. While cancer in children is rare, so when considering a clinical study, you will likely want to understand any differences between the standard treatment for your child’s disease and the treatment your child would receive in the study.

Learn More

Deciding to Participate

There are many reasons for participating in a clinical study, also called a clinical trial. Ultimately the decision to take part in research belongs to you, the patient. The decision you make will probably be a result of a combination of diverse reasons—some large, some small, some based on scientific evidence, some based on personal attitudes and feelings about health and disease.

Learn More

Health Insurance

Whether you are thinking about participating in a clinical study or not, health care costs and insurance coverage are major concerns for many patients and their families. An important factor in deciding to join a clinical study may be whether your health insurance will cover the costs.

Learn More