A trial looking at having imatinib for 3 or 5 years for gastrointestinal stromal tumour (SSG XXII)

Cancer type:

Soft tissue sarcoma




Phase 3

This trial is for people with gastrointestinal stromal tumour (GIST) who have had surgery and taken imatinib for 3 years.

Cancer Research UK supports this trial. 

More about this trial

Gastrointestinal stromal tumour (GIST) is a rare type of sarcoma. It usually starts in the wall of the stomach or the small bowel Open a glossary item.

The most common treatment for GIST is surgery and then a targeted therapy (biological therapy). This is to try to stop the cancer from coming back. 

A type of biological therapy often used is imatinib (Glivec). It works by blocking a protein called tyrosine kinase that tells cells to divide and grow. Blocking this protein might stop cancer cells from coming back.       

You usually take imatinib for 3 years after surgery and then have regular follow ups. But doctors want to find out if taking imatinib for 5 years is better at stopping GIST from coming back.  

In this trial you have 1 of the following: 

  • imatinib for 3 years and regular follow up (standard treatment Open a glossary item)
  • imatinib for 5 years and regular follow up (extended treatment)

The main aims of this trial are to:

  • find out if having imatinib for 5 years is better than 3 years
  • learn about the side effects of having imatinib for 5 years
  • learn more about the quality of life Open a glossary item

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. 

You may be able to join this trial if all of the following apply.

  • You have a gastrointestinal stromal tumour (GIST)
  • You have had an operation to remove the GIST and you have taken imatinib for 3 years
  • You have a sample of cancer (a tumour tissue sample) available. The trial team will check this
  • You have had a test to check for certain changes (mutations) in genes Open a glossary item. Your doctor will check this
  • Your doctor thinks there is a high risk of your GIST coming back (recurrence). Your doctor can tell you more about this 
  • You have satisfactory blood tests results
  • You are able to swallow tablets
  • You are well enough to be up and about for at least half the day (performance status 0, 1 or 2
  • You are at least 18 years old
  • You are willing to use reliable contraception during the trial and for 3 months afterwards if there is any chance you or your partner could become pregnant 

You cannot join this trial if any of these apply. 

Cancer related

  • Your GIST has come back or spread to another part of the body (metastatic)  
  • Your GIST has a certain change (mutation) in a gene called PDGFRA. Your doctor will check this
  • Your doctor thinks you need to have imatinib for more than 3 years (life long imatinib)  
  • You have stopped taking imatinib for more than 4 weeks 
  • You have taken imatinib before surgery (neoadjuvant) for more than 12 months
  • You have taken imatinib for less than 35 or more than 38 months
  • You take less than 200 mg or more than 800 mg of imatinib every day
  • You are having, or have had in the past 3 years, an experimental cancer treatment 
  • You have had another cancer in the past 5 years apart from basal cell skin cancer, an early cancer (carcinoma in situ Open a glossary item) of the cervix that has been successfully treated, a small (less than 2 cm) breast cancer that hasn't spread to the lymph nodes (T1N0M0), or a prostate cancer that has a low Gleason score (less than 8)

Medical conditions

  • You have HIV 
  • You have active hepatitis B, or hepatitis B that keeps coming back (chronic) 
  • You have heart problems such as congestive heart failure that is causing symptoms or you have had a heart attack in the past 6 months
  • You have an infection  Open a glossary itemthat isn’t controlled 
  • You have diabetes, kidney problems or any other serious medical condition that isn’t controlled   


  • You are pregnant or breastfeeding

Trial design

This is an international phase 3 trial. Researchers hope that around 300 people from Europe and about 20 people from the UK will take part. 

This trial is randomised. The people taking part are put into 1 of the following treatment groups by computer: 

  • imatinib for 3 years and regular follow up (standard treatment)
  • imatinib for 5 years and regular follow up (extended treatment)

Neither you nor your doctor are able to decide which group you are in. 

study diagram

Standard treatment
Imatinib are tablets that you take every day, once a day. You take them for 3 years (36 months). Then you have regular follow up. 
Extended treatment 
You take imatinib tablets for an extra 2 years (5 years in total). Then you have regular follow up. 

You start taking 400 mg of imatinib. Then the dose might change. It depends on any side effects you have. 

Quality of life
You complete a quality of life questionnaire every 3 months. It takes about 10 minutes to complete each time. 
The questionnaire asks about how you have been feeling and what side affects you have had.

Blood tests
You have extra blood tests as part of this trial. The researchers want to look for certain substances (such as proteins) and cells in your bloodstream. 

You have the extra blood tests before the start of the trial and at set times during the treatment or regular follow up. If possible, you have the extra blood samples at the same time you have routine blood tests.  

Sample of tissue 
Researchers will ask to use a tissue sample of your cancer taken during surgery. They want to learn more about how GIST develops and how the treatment works. 

Hospital visits

You see a doctor and have some tests before taking part. These tests might include: 

During the trial, you see the doctor for blood tests and a physical examination every 3 months for 4 years. Then: 

  • every 6 months for 1 year
  • once a year for 5 years 

You have a CT scan every 6 months. This continues for 5 years. You then have a CT scan every year, for 5 years.

Side effects

The trial team monitor you during the time you have treatment and 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 trial.

The most common side effects of imatinib are: 

  • a drop in blood cells causing an increased risk of infection, bleeding problems, tiredness and breathlessness 
  • tiredness
  • feeling or being sick
  • diarrhoea or constipation   
  • loss of appetite and weight changes 
  • liver problems
  • skin changes such as skin rashes, dry skin, redness and sensitivity to sunlight 
  • increased sweating at night
  • tingling or pricking sensation, reduced sense of touch or numbness
  • eye problems such as watery or dry eyes, blurred vision and redness
  • difficulty sleeping
  • hair loss (alopecia)
  • pain in your muscles, joints, bones and tummy (abdominal) 
  • headaches and dizziness
  • flu like symptoms (including fever, chills and rigors) 
  • indigestion (heartburn), bloating and passing wind 
  • bleeding 
  • dry mouth or taste changes 
  • shortness of breath, cough 
  • swollen face and joints

We have more information about imatinib



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 Ramesh Bulusu 

Supported by

Cambridge University Hospitals NHS Foundation Trust
Cancer Research UK 
Scandinavian Sarcoma Group (SSG)
GIST Cancer UK

Other information

This is Cancer Research UK trial number CRUK/15/073

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.

Charlie took part in a trial to try new treatments

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“I think it’s really important that people keep signing up to these type of trials to push research forward.”

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