Clinical trials are research studies. All clinical trials are done in steps, called phases. These phases are numbered 0, I, II, III, and IV (0, 1, 2, 3, and 4).

New cancer treatments must go through different phases before they’re available for everyone. If the treatment is successful in one phase, it will move on to the next one. People most often take part in just one phase of a clinical trial.

MSK is a leader in cancer clinical trials. We often have many trials at a time, researching different types of cancers.

MSK is home to one of the largest clinical trial programs in the country. This means that we offer more cancer clinical trials than many other cancer centers in the United States. We offer clinical trials in Manhattan and at some of our regional locations, including:

• Long Island: Commack and Nassau
• New Jersey: Basking Ridge, Bergen, and Monmouth
• Westchester: West Harrison

The clinical trials done at MSK lead to many approvals of new drugs by the U.S. Food and Drug Administration (FDA). Through clinical trials, MSK patients have access to the latest drugs. This can be helpful for people who:

• Have cancer that did not respond to standard treatments, or that stopped responding.
• Have a type of disease that has no, or very few, approved treatments.

There are also clinical trials available for people with a new cancer diagnosis. This can be the first option of treatment for some people. Clinical trials are not only for people who don’t have many treatment options.

Researchers must follow strict rules to make sure that clinical trials are as safe as possible. These rules are enforced by the federal government.

Every clinical trial is approved and monitored by an Institutional Review Board (IRB) and other government agencies to make sure the trial is safe. The IRB makes sure that the risks are as low as possible. It makes sure the clinical trials may offer more benefits than risks.

At MSK, our scientists plan everything very carefully. Their research is approved by the IRB. They closely watch over people in the trial and follow rules to handle any problems. They can stop the trial if something does not seem right. Clinical trials are designed to keep you safe.

Before you decide to join, our researchers will talk with you about what will happen and any possible issues.

Joining a trial is voluntary. If you feel uncomfortable or do not want to stay in the trial, you can stop anytime.

In all clinical trials at MSK, our doctors and scientists work closely together. Their job is to watch over clinical trials so that the people who join them are kept safe.

Phase 1 clinical trials

The first step in testing a new treatment is called a phase 1 clinical trial. Researchers want to learn the right dosage of a drug that works best for a certain type of cancer. They want to understand how the treatment affects the body.

Risks of phase 1 clinical trials

Sometimes the treatments being studied work, but researchers do not know for sure they will work. For these reasons, phase 1 studies most often involve only a small group, just 20 to 80 people.

In phase 1 clinical trials, researchers carefully test the safety of a new treatment in this small group of people. It’s very important in this phase to closely monitor (watch) people. Researchers want to find and solve any problems right away.

The first few people in a phase 1 study most often get a low dose of the new treatment. The goal is to have only minor side effects, or none at all.

If that happens, the next few people get a dose that’s just a little higher. This process keeps going until doctors find the dose most likely to work without bad side effects.

MSK has an Early Drug Development Service that includes phase 1 trials. Its goal is to bring drugs that work well to people faster.

Phase 2 clinical trials

A phase 2 clinical trial most often studies how well a new treatment works in a larger group. The group has up to 100 people who have a similar type of cancer. People are treated using the dose and method that the phase I trial found was safest and worked best.

How phase 2 clinical trials work

Some phase 2 research studies use a method called randomization to assign people to a treatment group. People are chosen by chance to join a group. Each group can get different treatments, different doses of the same drug, or the same treatment given in different ways.

People in studies that use randomization do not get to choose their group. Randomized studies help researchers learn which treatment is the safest and works best.

In many phase 2 randomized cancer trials, one group will get the standard treatment. The other group gets the standard treatment and the new treatment. Phase 2 trials also can look at whether a treatment offers a better quality of life.

A drug may be very successful in a phase 2 trial. Sometimes, researchers may ask the FDA if they can skip a phase 3 trial. This would let them offer the treatment to other doctors for their patients, too. 

Combined phase 1 and 2 clinical trials

A combined phase 1 and phase 2 clinical trial has parts from both of those phases. Doing both phases together may let us develop new treatments faster.

Phase 1: In a small group of people, phase 1 often focuses on the safety and dosage of a new treatment.

Phase 2: In a larger group of people, phase 2 looks at how well the treatment works and monitors its safety.

Combining phases 1 and 2 makes research go faster. It lets researchers get information at the same time about safety and how well the treatment works.

Combined trials have different kinds of designs and goals. They depend on what researchers are studying, and the goals of the research study. 

Phase 3 clinical trials

Phase 3 clinical trials compare new treatments with standard treatments. They also can compare the response to a new treatment with how a group of patients responded to a different treatment. In phase 3 trials, researchers often try to see which treatment is safer and works best. There are usually between 300 and 3,000 people in a phase 3 study.

How a phase 3 clinical trial works

In phase 3 clinical trials, doctors look at a few things. They test whether the new treatment helps people live a longer life, with a better quality of life. They look for whether there are fewer (less) side effects. They learn whether cancer came back in fewer people compared with people who had the standard treatment.

Everyone in a phase 3 trial is randomly assigned to a group that gets the new treatment, or to a group that gets the standard therapy. People in studies that use randomization do not get to choose their group.

A drug may be successful in a phase 3 trial. If so, the researchers may ask the FDA if they can offer the treatment to other doctors for their patients, too.

Sometimes, a phase 3 clinical trial may be stopped. This happens when the researchers see that one group is doing much better than the other group. This keeps patients safe.

If it’s the new treatment that’s working better than the standard treatment, then everyone is offered the new treatment. If the standard treatment is working better than the new treatment, everyone is offered the standard treatment. 

Combined phase 2 and 3 clinical trials

A combined phase 1 and phase 2 clinical trial has parts from both phases to test a new treatment. Combining phases 2 and 3 may let us develop new treatments faster.

Phase 2 trials look at how well the treatment works and monitors its safety. During this phase, researchers get information on how the treatment works and whether it has side effects.

Phase 3 trials test treatments with a bigger group of people. This phase confirms how well the treatment works. It monitors side effects and compares this treatment with a standard treatment.

Doing both phases together makes research go faster. It lets researchers get information at the same time about safety and how well the treatment works. Researchers can get strong data about the treatment’s safety and how well it works in a bigger group of people.

Phase 4 clinical trials

After the FDA approves a treatment, it may be studied more in a phase 4 trial. We do not do phase 4 clinical trials at MSK.

Phase 4 trials assess the side effects, risks, and benefits of a drug or other therapy. They test it over a long period of time and in a larger number of people than in phase 3 trials. Thousands of people are in a phase 4 trial.