A trial of mercaptopurine and methotrexate for advanced breast or ovarian cancer in people with BRCA gene faults (6MP-BRCA)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Breast cancer
Ovarian cancer




Phase 2

This trial is looking at 2 chemotherapy drugs called mercaptopurine and methotrexate. It is for people with an inherited fault in the BRCA1 Open a glossary item or BRCA2 Open a glossary item gene who have locally advanced or secondary breast cancer, or ovarian cancer, fallopian tube cancer or primary peritoneal cancer that has come back after other treatment. This trial is supported by Cancer Research UK.

People with breast or ovarian cancer caused by a BRCA 1 or BRCA 2 gene fault currently have the same treatments as people who don’t have a BRCA gene fault. But we know from research that these cancers may be more sensitive to certain types of chemotherapy.

In this trial, researchers are looking at a chemotherapy drug called mercaptopurine (also known as 6MP). This drug is already used to treat leukaemia Open a glossary item and is often given alongside another chemotherapy drug called methotrexate.

The aims of this trial are to find out

  • How well a combination of 6MP and methotrexate works for breast cancer, ovarian cancer, fallopian tube cancer or primary peritoneal cancer in people with BRCA gene faults
  • What the side effects are

Who can enter

You can enter this trial if you have a faulty BRCA1 or BRCA2 gene and have either


You must also

  • Have cancer that can be measured on a scan
  • Be well enough to be up and about for at least half the day (performance status 0, 1 or 2)
  • Have satisfactory blood test results
  • Be willing to use at least 2 reliable forms of contraception during the trial and for 6 months afterwards if there is any chance you could become pregnant
  • Be at least 18 years old

You cannot enter this trial if you

  • Have very low levels of an enzyme Open a glossary item called TPMT due to a genetic fault - this would put you at greater risk of side effects from the study drugs and you must give a blood sample to test for this before you can join the trial
  • Have cancer that has spread to your brain or spinal cord, unless this has been successfully treated, has not got any worse for at least 3 months and you have not taken steroids for at least 3 weeks
  • Have had any other anti cancer treatment in the last 4 weeks (apart from radiotherapy for symptoms)
  • Have not recovered from the side effects of earlier treatment
  • Have any other cancer that requires treatment or could affect the results of this trial
  • Have a condition that means you can’t take 6MP including alcoholism, a liver disease called porphyria, or certain types of heart or lung disease (the trial doctor can advise you about this)
  • Have a family history of liver failure
  • Are known to be sensitive to either of the drugs in the trial
  • Are known to be HIV, hepatitis B or hepatitis C positive
  • Are pregnant or breastfeeding

Trial design

This phase 2 trial will recruit 65 people in the UK. Everybody taking part will have 6MP and methotrexate tablets.

You take 6MP each morning about an hour after eating. You take methotrexate once a week. As long as you don’t have bad side effects, you can carry on having the treatment for as long as it helps you.

You will be asked to fill out a questionnaire at the beginning of the trial, then after 3 months, 6 months and a year. The questionnaire will ask about any side effects you have had and how you have been feeling. This is called a quality of life study. If you finish treatment within the year, you fill out a questionnaire then too.

The trial team will ask you to give some extra blood samples during the trial. They may also ask you to have an extra biopsy Open a glossary item at the beginning of the trial and again after about 7 weeks of treatment. They will use these blood and tissue samples to study your DNA. The researchers hope to learn more about why some people respond to these drugs better than others and why some people have more side effects than others. If you don’t want to give the samples for research, you don’t have to. You can still take part in the trial.

Hospital visits

You will see the doctors and have some tests before you start treatment. The tests include

  • Physical examination
  • Blood tests
  • Heart trace (ECG Open a glossary item)
  • CT scan

You go to hospital to see the trial team

  • Once a week for the first 4 weeks of treatment
  • Every 2 weeks for the next 8 weeks
  • Then monthly for as long as you carry on with treatment

You have a number of blood tests throughout the trial and a CT scan every 8 weeks during treatment. When you finish treatment, you go back and see the trial team about 4 weeks later. After that, you will have follow up appointments every 3 months.

Side effects

The most common side effects of the chemotherapy drugs include

There is more information about the possible side effects of mercaptopurine and methotrexate on CancerHelp UK.

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 Shibani Nicum

Supported by

Cancer Research UK
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer
University of Oxford

Other information

This is Cancer Research UK trial number CRUK/10/049.

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 6914

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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