A trial looking at avelumab and chemotherapy for bowel cancer (POLEM)

Cancer type:

Bowel (colorectal) cancer
Colon cancer




Phase 3
This trial is for people with cancer that started in the large bowel (colon). It is for people who have had surgery and are going to have chemotherapy to lower the chances of the cancer coming back. 
Everyone taking part has changes (mutations) in the following genes Open a glossary item:
  • mismatch repair 
  • POLE

More about this trial

Surgery is a common treatment for bowel cancer that hasn’t spread to a distant part of the body. After surgery, you might have chemotherapy to lower the chances of the cancer coming back. This is called adjuvant treatment Open a glossary item
In this trial, researchers are looking at whether adding a drug called avelumab to chemotherapy improves chemotherapy after surgery. 
Avelumab (Bavencio) is a type of immunotherapy. It targets and blocks a protein called PD-L1 on the surface of the tumour and certain immune cells. Blocking PD-L1 activates the immune cells to find and kill the cancer. 
Everyone taking part in this trial has one of the following treatments after surgery:
  • chemotherapy 
  • chemotherapy and avelumab 
The chemotherapy treatment you have in this trial is one of the following:
The main aim of this trial is to find out how well chemotherapy and avelumab work as a treatment for bowel cancer. 

Who can enter

The following bullet points list the entry conditions for this trial. Talk to your doctor or the trial team 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 trial if all of the following apply:
  • you have adenocarcinoma of the colon (bowel cancer) that hasn’t spread to a distant part of the body such as the liver, lungs or bones (stage 3)
  • your cancer has changes (mutations) in the mismatch repair or POLE gene
  • you have had surgery to remove the cancer and a border of healthy tissue around it. This border of tissue should not contain any cancer cells (clear margins Open a glossary item)
  • your doctor thinks that you are well enough to have chemotherapy after surgery (adjuvant treatment)
  • you have satisfactory blood test results  
  • you can do everything apart from heavy physical work (performance status 0 or 1)  
  • you are at least 18 years old  
  • you are willing to use reliable contraception during treatment and for up to 6 months afterwards if there is any chance that you or your partner could become pregnant 
Who can’t take part
Cancer related
You cannot join this trial if any of these apply:
  • your cancer started in the back passage (rectum Open a glossary item
  • you can’t start chemotherapy within 3 months of your bowel cancer surgery for any reason 
  • you have moderate or severe side effects from previous treatment apart from hair loss and numbness or tingling in fingers and toes 
  • you have had another cancer in the last 2 years part from non melanoma skin cancer Open a glossary item, a localised prostate cancer, or carcinoma in situ Open a glossary item of the cervix or breast that has been successfully treated 
Medical conditions
You cannot join this trial if any of these apply. You:
  • have had an organ or stem cell transplant Open a glossary item from a donor
  • have an active autoimmune disease Open a glossary item unless it is type 1 diabetes Open a glossary item, a thyroid problem called hypothyroidism Open a glossary item, or a skin condition called psoriasis, vitiligo or eczema that is stable
  • take drugs that damp down your immune system Open a glossary item  such as steroids unless it is a very small dose or an inhaler
  • have heart problems such as irregular heart rhythm (arrhythmia), angina Open a glossary item that isn’t controlled, moderate or severe congestive heart disease, or you have had a heart attack in the last 6 months
  • have had a stroke Open a glossary item in the last 6 months
  • have lung problems such as pneumonitis Open a glossary item
  • have inflammation of the bowel (colitis) or the heart muscle (myocarditis) 
  • have HIV 
  • have hepatitis B or hepatitis C 
  • drink an amount of alcohol or take an amount of drugs that is a concern for your doctor 
  • have any other medical condition or mental health problem that the trial team think could affect you taking part 
You cannot join this trial if any of these apply. You:
  • are pregnant or breastfeeding 
  • are sensitive to avelumab or any other similar drug 
  • have had a live vaccine in the last month or are going to have a live vaccine during this trial 

Trial design

This is a phase 3 trial. Researchers hope that up to 402 people from the UK will agree to take part. 
It is a randomised trial. Everyone taking part is put into 1 of the following groups by computer: 
  • chemotherapy 
  • chemotherapy and avelumab
Neither you nor your doctor can choose which group you are in. 

Everyone has 1 of the following:

  • capecitabine 
  • capecitabine and oxaliplatin (CAPOX)
This is the same as the standard treatment. Your doctor can tell you which treatment you will have. 
You have chemotherapy in cycles of treatment Open a glossary item that last 3 weeks.
You have capecitabine (Xeloda) as tablets that you swallow whole, twice a day. And oxaliplatin (Eloxatin) as a drip that you have into your bloodstream (intravenously) on the 1st day of each cycle of treatment. 
You have up to 8 treatment cycles of capecitabine, taking around 6 months in total. Or you have up to 4 treatment cycles of capecitabine and oxaliplatin, taking around 3 months. 
Chemotherapy and avelumab
You have 1 of the following chemotherapy treatments:
  • up to 8 treatment cycles of capecitabine
  • up to 4 treatment cycles of capecitabine and oxaliplatin
Your doctor can tell you which treatment you will have. 
After chemotherapy, you have avelumab as a drip into your bloodstream every 2 weeks. You can have up to 12 avelumab treatments, taking about 6 months. 
Quality of life 
Everybody taking part completes quality of life questionnaires before the start of treatment and:
  • every 3 months during chemotherapy 
  • about 5 months after the start of avelumab (if you have this) 
The questionnaires ask about how you have been feeling and what side effects you have had. 
Blood tests
You have extra blood tests as part of this trial. You have them before the start of treatment and then:
  • before the 1st and 2nd avelumab treatment (if you have this)
  • a month after the end of treatment 
Researchers want to look for certain proteins (biomarkers Open a glossary item) that can help to tell how well the treatment is working.
Tissue sample
The trial team will ask to use a tissue sample of your cancer taken when you had surgery or a biopsy Open a glossary item. Researchers want to learn more about why some people have worse side effects from treatment than others. 
You don’t have to agree to this if you don’t want to. You can still take part in this trial.

Hospital visits

You see a doctor and have some tests before taking part. These tests might include:
  • a physical examination
  • a CT scan 
  • heart trace (ECG Open a glossary item
  • blood tests
During chemotherapy, you see the trial team every 3 weeks. You have blood tests and might have a physical examination every time you see them. 
If you have avelumab, you see the trial team every 2 weeks during treatment. 
When you finish treatment, you see the trial team after a month. You then see the trial team:
  • every 3 months for a year
  • then every 6 months for 2 years
  • then every year for 4 years
This is called follow up. During follow up, you have blood tests and physical examinations at set times. You also complete questionnaires. 
You have a CT scan 1, 2 and 3 years after the end of treatment. You also have a colonoscopy after 1 and 4 years of treatment.  

Side effects

The trial team monitor you during treatment and afterwards. You have a phone number to call them if you are worried about anything. The team will tell you about all the possible side effects before you start the treatment. 
Avelumab affects the immune system. This may cause inflammation in different parts of the body which can cause serious side effects. Side effects can happen during treatment or some months after treatment has finished. Some side effects can be life threatening. 
The most common side effects of avelumab are:
We have information about the possible side effects of:



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 Tony Dhillon

Supported by

The Royal Marsden NHS Foundation Trust (GI & Lymphoma Clinical Trials Office)
Merck Serono

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.

Over 60,000 cancer patients enrolled on clinical trials in the UK last year.

Last reviewed:

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