A study looking at the microbiome in the body and if it can show how well immunotherapy works and who might get side effects (MITRE)

Cancer type:

All cancer types





The natural bacteria that lives in your mouth and gut is the microbiome. It can affect how the immune system works. 

The immune system fights infection and diseases such as cancer. 

This trial is for people with cancer that has spread (advanced cancer). 

More about this trial

Immunotherapy Open a glossary item uses your immune system to fight cancer. It works by helping your immune system Open a glossary item  recognise and attack cancer cells. 

A checkpoint inhibitor is one type of immunotherapy. 

How Checkpoint Inhibitors work


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These drugs work well for some cancers. But they don’t work for everyone and cause side effects. For some people these side effects can be life threatening.

Researchers are looking for ways to try and find out who might benefit from having these drugs and who might have bad side effects. They will do this by looking for substances (biomarkers Open a glossary item) in samples of:

  • poo (stool)
  • mouth swab 
  • blood
  • sample of your cancer tissue, if available 
  • sample of tissue from the body part affected by a severe side effect, if available

In this study researchers are looking for people with cancer who are having a checkpoint inhibitor. They are also looking for people who don’t have cancer. For this they are asking people who live in the same household for samples (poo, mouth swab and blood) as well. The microbiome samples from these people should be similar to those of the cancer patients. And so will act as a reference for microbiomes for the patient they live with. 

The main aim of this trial is to find out whether the gut microbiome can predict how well checkpoint inhibitors can work for people with advanced cancer.  

Who can enter

The following bullet points list the entry conditions for this study. Talk to your doctor or the study if you are unsure about any of these. They will be able to advise you. 

Who can take part

You may be able to join this study if all you have or had 1 of the following:

And all of the following apply. You:

  • are to have treatment with an immunotherapy called a PD-1 inhibitor such as nivolumab and pembrolizumab, PD- L1 inhibitor such as durvalumab and or a CTLA-4 inhibitor such as ipilimumab either to relieve symptoms or as treatment after surgery 
  • have not been treated with radiotherapy for your current cancer
  • might or might not have had surgery to remove your cancer. If your cancer has not been removed by surgery, it must be measurable either on a scan Open a glossary item or by the doctor. 
  • are at least 18 years old
  • are willing and able to attend clinics, treatment plans and sample collections for the duration of the study 

Who can’t take part

You cannot join this study if any of these apply. You:

  • had another cancer in the past year or you need additional treatment for another cancer. You might be able to join if the cancer was treated and there is no sign of it on tests or examinations (in complete remission).
  • have chest pain that isn’t controlled, have had a heart attack or new chest pain (angina) in the past 6 months
  • have an active infection
  • have liver disease such as cirrhosis, hepatitis B or hepatitis C
  • have an active, severe or uncontrolled autoimmune disease such as Crohn’s disease or ulcerative colitis
  • are taking medication that affects your immune system such as steroids unless it is a low dose, your doctor will tell you more. You can join the study if you are using inhalers or a steroid cream
  • are pregnant or planning to become pregnant  
  • are breastfeeding

Trial design

There are 2 groups in this study:

  • people who have cancer 
  • people who live with someone with cancer  

People who have cancer            
In this group the team need up to 1,800 people. You give 4 different types of samples (poo, mouth swab, blood and tissue). 

You give a poo (stool) sample before starting treatment then at:

  • 3 to 6 weeks 
  • 9 to 12 weeks 
  • 6 months
  • 1 year if you are still having treatment

During your 1st year of treatment if your cancer starts to grow again or comes back you give poo sample then. 

You can give the sample where it is most convenient for you. The team give you a kit to take the sample. This includes a stamped addressed envelope to return the sample if you take it at home. 

You give a mouth swab sample from the inside of your cheek, gumline and over your tongue. The team give you a kit to take home to do this. You can return it in the same stamped addressed envelope as your poo sample. 

You give 3 extra blood samples. The team takes these when you have your routine blood tests as part of your treatment. 

The team ask your permission to get a sample of cancer tissue (biopsy Open a glossary item) from when you were diagnosed or when you have surgery to remove the cancer. When you’re having treatment if you have side effects the team will take a biopsy from the part of the body affected such as the skin or liver. 

People who live with someone with cancer         
The team want samples of microbiome from people who don’t have cancer. So as part of the study they might ask an adult who lives with the person with cancer to take part. The team need up to 360 people to join. 

These people who don’t have cancer go to the clinic appointment with the person who invited them. This is for the team to talk to about the study and to confirm that they agree to take part. 

They give a poo sample. They can do this at the hospital or take a kit home to do it. In the kit is a stamped addressed envelope to return it. 

They also give a mouth swab sample from the inside of the cheek, gumline and over their tongue. They can do this test at home. You can return it in the same stamped addressed envelope as their poo sample. 

They also need to give a blood sample at the hospital. 

The doctor will also ask them some personal questions about their:

  • general health
  • diet
  • lifestyle

As part of the study the team want to find out how COVID-19 can affect your microbiome. This is open to both those with cancer and their household members. 

As part of this the team will offer to take a sample from your nose and back of the throat using a swab. And test these samples for COVID-19. You don’t have to agree to take part in the COVID-19 testing. 

You are told the results of the test and can to talk about them with the doctor. 

The team also want to test your poo and blood samples you have already donated for COVID-19. 

Hospital visits

For people with cancer there are no extra hospital visits. 

For the person who lives with someone who has cancer you go to the hospital once. 

Side effects

The study team monitor you during treatment and afterwards. Contact your advice line or tell your doctor or nurse if any side effects are bad or not getting better. 

Checkpoint inhibitors can affect the immune system. They may cause inflammation in different parts of the body which can cause serious side effects. This could happen during treatment, or some months after treatment has finished. Rarely, these side effects could be life threatening.

If you have any of these side effects, you should tell the doctor or nurse as soon as possible that you are on or have been on an immunotherapy. 


Kings Lynn

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Dr Pippa Corrie

Supported by

Cambridge University Hospitals NHS Foundation Trust
Cancer Research UK
Microbiotica ltd

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Last reviewed:

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