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A colorectal cancer clinical trial - CO33

A study of two new immunotherapy drugs in combination with the usual treatment for colorectal cancer
Disease Site
Gastro-Intestinal Clinical Trials
Trial Code
CO.33 ǀ NCT07152821
Trial Status
Open to patient enrollment

What is the purpose of this study?

The purpose of this study is to compare the usual approach of patients receiving best supportive care measures alone after exhausting all available treatments to adding two study drugs to the usual approach to treat colorectal cancer. Best supportive care is defined as supportive care with drugs and other treatments that may help to make you feel better or may improve your quality of life. This study will help the study doctors find out if this different approach is better than the usual approach.

Why is this study important?

The two drugs being studied are new types of immunotherapy being developed for the treatment of colorectal cancer. Laboratory tests show that they may help slow the growth of colorectal cancer. The new drugs have been studied in people with colorectal cancer and seem promising, but it is not clear if they can offer better results than the usual approach.

Who can participate in this study?

This trial is for patients:

  • aged 18 and older
  • with colorectal cancer that cannot be removed by surgery
  • who do not have any treatment options left that can stop or slow their cancer from continuing to grow

This trial is not for individuals:

  • whose body’s immune (protection) system does not work correctly
  • who have had a solid organ transplant or bone marrow transplant
  • who have another serious health problem that is not under control
What are the risks?
  • If you choose to take part in this study, there is a risk that the study drugs may not be better than the usual approach for your cancer. There is also a risk that you could have side effects from the study drugs. Some of the most common side effects that the study doctors know about are: diarrhea, nausea or vomiting, fatigue/tiredness, fever/chills and muscle pain or joint aches. You will find details of all side effects in the consent document.
What can I expect?
  • If you choose to take part in this study, you will be randomly placed in one of two groups and you will receive either the new drugs plus the usual approach of best supportive care or best supportive care alone.
  • In this study, you will also be asked to complete a few questionnaires at different times, to understand your quality of life.

How can I find out more or join the study?

Talk to your cancer doctor (oncologist) if you are considering joining this study. You can share this information with others and ask if they think joining the trial may be a good option for you.

Before you join this study, you will be asked to review an Informed Consent document which will tell you more about why the research is being done and your role as a participant. You will have an opportunity to discuss anything that is not clear and ask any questions you have.

Joining this study is entirely up to you and you can decide to leave at any time without giving a reason. Your decision to join or leave the trial will not affect your standard medical care.

The CO.33 study is currently enrolling patients at cancer centres in Canada. For a full list of participating cancer centres please visit www.clinicaltrials.gov and search using NCT07152821.

Use this trial information for your conversation with your health care team

Participating centres

Information coming soon.