Clinical Trial Phases

Cancer clinical trials are used for a variety of reasons. Some of the most common reasons include:

• Testing existing cancer treatments on different cancer types

• Understanding how to use approved treatments in different combinations for better results

• Testing new cancer therapies

Placebos

Many patients ask if there’s a chance that they will receive an inactive treatment, called a placebo. The use of placebos in cancer clinical trials is rare. When placebos, or inactive medications, are used, they are never given in place of the best known standard of care. Instead, they may be used alongside an active treatment. In most trials, participants receive either the investigational therapy or an existing, approved cancer treatment, so patients can feel confident they are receiving care while taking part in a clinical trial.

What Do the Research Phases Mean?

When a clinical trial is launched by a lead physician(s), called the lead investigator(s), the trial will be classified in one of four different phases. Most new cancer treatments will typically go through Phases I, II, and III. Not all therapies have a Phase IV because it is not always necessary for proving a new cancer treatment safe and effective.

Phase I

In Phase I cancer clinical trials, researchers test a study drug for the first time to assess the safety of the new drug. This typically involves a small group of up to 60 people, who are monitored very carefully. Every patient is given the investigational drug.

This phase may also look at:

• Dosage range and schedule

• Early signs of how effective the treatment is

• How the new treatment should be given (by mouth, vein, etc.)

• The therapy’s side effects

Phase II

In Phase II cancer clinical trials, particular emphasis is given to whether the therapy is effective at treating a specific type of cancer. There is no placebo given, but participants may be divided into groups where each group gets a slightly different dose or schedule that will tell the investigators which way appears to work best with tolerable side effects.

Phase II trials usually involve more people than the Phase I trials, but fewer than 100 people who all meet specific requirements set by the investigators.

Phase III

In Phase III cancer clinical trials, the new cancer therapy is compared carefully to the current treatment(s) available for that type of cancer. In this phase, which usually involves thousands of participants, patients may be separated into small groups and randomized to different treatment groups. Some will receive the standard treatment that is already available, and some will receive the new treatment being tested. Many times, neither the doctor nor the patient knows which cancer treatment they are receiving, so that results cannot be influenced with conscious or unconscious bias.

The goal of phase III trials is to get FDA approval by showing that the investigational treatment is more effective than existing treatments.

Phase IV

In Phase IV cancer clinical trials, the cancer therapy is tested after it has been approved by the FDA for a specific use. They are used to collect information about a therapy’s long-term effects on the patient’s quality of life, length of life, and any unexpected long-term side effects.

Phase IV trials may also be used to try new combinations of approved therapies to determine if there are better outcomes.

Clinical Trial Phases at Affiliated Oncologists

Most clinical trials available through Affiliated Oncologists are Phase II, III, or IV. If your doctor suggests a clinical trial for you, you will be told which phase it is and what you may want to consider before agreeing to participate. Our cancer research specialists have also answered frequently asked questions about cancer clinical trials.

Speak with your AO cancer care team, who can let you know if participation in groundbreaking clinical trials may be available to you