A trial of MK3475 for advanced cancers

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

Cancer type:

Anal cancer
Breast cancer
Head and neck cancers
Lung cancer
Neuroendocrine tumour (NET)
Prostate cancer
Salivary gland cancer
Small cell lung cancer
Thyroid cancer
Vulval cancer
Womb (uterine or endometrial) cancer




Phase 1

This trial is looking at a new drug called MK3475 (also known as pembrolizumab) for certain types of advanced cancer. It is for people who have cancer that produces large amounts of a substance called PD-L1.

Researchers are looking for new ways to treat cancers that have grown into surrounding tissue or spread to another part of the body. In this trial they are looking at a drug called MK3475.

MK3475 works by stopping 2 substances called PD1 and PD-L1 working together. If these substances can’t work together, cells in the immune system are able to attack cancer cells.

  • PD1 is on the surface of cells in your immune system
  • PD-L1 is on the surface of cancer cells

If a cancer has large amounts of PD-L1, it is described as being PD-L1 positive.

This trial is recruiting people who have 1 of about 20 different types of cancer.
To be able to take part, you must have a cancer that is PD-L1 positive.

The aims of the trial are to

  • See how well MK3475 works as a treatment for different types of PD-L1 positive cancer
  • Learn more about the side effects

Who can enter

You may be able to join this trial if you have one of these cancer types

And as well as the above, all of these must apply

  • There are no treatments available that could cure your cancer
  • Your cancer is PD-L1 positive (the trial team will test for this)
  • Your cancer has grown into surrounding body tissues or spread to another part of your body
  • Your cancer has got worse despite having other standard treatments Open a glossary item, there isn’t a standard treatment available, or your doctor thinks the standard treatment is not right for you
  • You are well enough to carry out all your normal activities, apart from heavy physical work (performance status of 0 or 1)
  • You have satisfactory blood test results
  • You are at least 18 years old
  • You are willing to use reliable contraception during the trial and for 4 months afterwards if there is any chance you or your partner could become pregnant

You cannot join this trial if any of these apply. You

  • Have cancer that has spread to your brain or the tissues surrounding your brain (you may be able to take part if you have cancer spread to your brain that has been successfully treated, has not got any worse in the last 4 weeks and you haven’t taken steroids for at least a week)
  • Have problems with your immune system or take drugs such as steroids Open a glossary item that damp it down (there are some exceptions to this that the trial team can explain)
  • Have had treatment for an autoimmune disease Open a glossary item in the last 3 months or have had a severe autoimmune disease in the past
  • Have a condition affecting your lungs called interstitial lung disease
  • Have had a drug called a monoclonal antibody in the last 4 weeks (or earlier if you haven’t recovered from any side effects)
  • Have had an experimental drug as part of another clinical trial in the last 4 weeks
  • Have had chemotherapy, biological therapy or radiotherapy in the last 2 weeks, or earlier if you haven’t recovered from any side effects apart from hair loss or nerve damage if this is only mild
  • Have another cancer apart from carcinoma in situ of the cervix or non melanoma skin cancer that has been successfully treated
  • Have an infection that needs treatment
  • Have any other medical condition or mental health problem that the trial team think could affect your taking part
  • Have already had a drug that targets PD-1, PD-L1 or a similar substance called PD-L2
  • Have had a drug called ipilimumab or another drug that works in a similar way
  • Are known to have HIV, hepatitis B or hepatitis C
  • Have had a live vaccine in the last month
  • Are pregnant or breastfeeding

Trial design

This is an international phase 1 trial. The researchers need 320 people to join the trial.

The trial team need a sample of your cancer (a biopsy) to test whether or not it is PD-L1 positive. They may be able to get a sample of your cancer that was removed when you had surgery or a biopsy in the past. If not, you will need to have a new biopsy.

The trial team will send the sample to a laboratory in the United States for testing. The laboratory will send the result back to your doctor in within a week.

If the test shows your cancer doesn’t have enough PD-L1, you can’t join the trial and your doctor will talk to you about other possible treatments.

If the test shows your cancer has enough PD-L-1 (it is PD-L1 positive), you may be able to take part. If you do, you have MK3475 through a drip into a vein once every 2 weeks. It takes an hour each time.

As long as you don’t have bad side effects, you can carry on having MK3475 for up to 2 years.

Hospital visits

You see the trial team and have some tests before you start treatment. The tests include

During treatment, you go to hospital every 2 weeks. Each visit lasts at least half a day.

You have regular blood tests. You have a CT or MRI scan every 8 weeks for the first 6 months and then every 3 months for the rest of the time you have treatment. If you have prostate cancer, you may also have bone scans during treatment.

If a scan shows that your cancer may have started to get worse, the trial team will ask you to have another scan 4 weeks later to confirm this.  During this 4 week period, you may be able to

  • Continue having MK3475
  • Stop taking it until the repeat scan
  • Stop taking it all together and discuss other possible treatments with your doctor

If the 2nd scan confirms that your cancer is getting worse, you stop treatment. If the 2nd scan shows the cancer has got smaller, you can carry on having MK3475.

If your cancer disappears completely after you have taken MK3475 for at least 6 months (24 weeks), you may stop treatment. You then have a scan every 8 weeks. If a scan shows that your cancer has come back again, you may be able to start having MK3475 again.

When you finish treatment, you see the trial team again about a month later. They will then contact you by phone to see how you are every 3 months.

If you stop treatment for any reason other than your cancer getting worse, you will see the trial team and have a scan every 8 weeks until your cancer does start to get worse, or you start another treatment.

If your cancer doesn’t get worse and you have MK3475 for the full 2 years, you have a scan every 8 weeks after finishing treatment. If a scan shows that your cancer is getting worse, the trial team may talk to you about starting MK3475 again. You may be able to have for up to 1 more year.

Side effects

As MK3475 is a new drug, there may be side effect we don’t know about. In earlier clinical trials, the most common side effects have been

The trial team will talk to you about all the possible side effects before you agree to take part.

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 Rhoda Molife

Supported by

Experimental Cancer Medicine Centre (ECMC)
Merck Sharp & Dohme

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 11969

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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