Clinical Trial Phases

There are a number of reasons why clinical trial phases are used as part of a cancer clinical trial. The following are some of the most common ones:

  • To test new treatments for cancer
  • To test existing treatments on cancers of a different type
  • To understand how treatments that are already approved can be used for better results in different combinations

What Does the Clinical Trial Phase Mean? 

After being initiated by the lead investigator – who is also the lead physician – a clinical trial is categorized as one of four distinct phases. In most cases, new cancer treatment will move through the three phases known as Phase I, Phase II and Phase III. 

In some cases, a Phase IV clinical trial might not be needed for a therapy. This is most often because this phase isn’t needed to prove that the cancer treatment is effective and safe. 

Phase I

During Phase 1 of a cancer clinical trial, the investigators are testing the study drug for the first time. This is primarily to evaluate if the therapy is safe.

Usually only a small group of participants – between 15 and 30 people – is used. They are monitored carefully throughout the process. A placebo is not part of Phase 1. 

This phase can also be used to gather information about the drug's side effects and the optimal dosage range. It might also explore the ideal delivery method, such as by vein, mouth or another route, for the drug. 

Phase II

Cancer clinical trials that are in Phase II place emphasis on evaluating the drug for its effectiveness at treating a particular type of cancer. While no patient is given a placebo, participants might be placed into specific groups.

If that is the case, each group receives the therapy on a different schedule or using a different dose. This approach is designed to tell the researchers which method works the best and with side effects that are tolerated. 

In most cases, there more participants are used during Phase II trials than Phase I trials. However, there are usually fewer than 100 people involved who have met the researchers' requirements. 

Phase III

During Phase III clinical trials for new cancer therapies, the treatment is carefully compared to those that are already available for the specific type of cancer. Participants during this phase might be grouped together randomly. 

Some participants will receive the new cancer treatment that is being tested while others will receive a therapy that is already being used. In many cases, neither the patient nor the investigators know which participant is receiving which type of treatment. This helps preserve the integrity of the results. 

Phase IV

Once a cancer therapy has already been approved for a particular use, it could move on to Phase IV testing. Typically, these tests involve hundreds – or even thousands – of participants who are followed and evaluated over the course of many years. 

The purpose of putting a cancer treatment through Phase IV of a clinical trial is to determine the effect the therapy has on the patient over the long term. During this phase, the researchers will collect information regarding the patient's quality of life as well as the length of their life. In addition, any long-term side effects that were not anticipated by the researchers will be noted. 

It is also during Phase IV that the investigators might combine already-approved therapies in new ways. After studying these new combinations, the investigators can determine if the patients had better outcomes. 

Clinical Trial Phases Offered at Blue Ridge Cancer Care

Blue Ridge Cancer Care offers clinical trials that are Phase I, II, III and IV trials. However, all patients are informed of the phase of the trial as well as any considerations to keep in mind before agreeing to participate. Contact your cancer care team to learn about any clinical trials that might be right for you.