A trial looking at pembrolizumab for people with melanoma (KEYNOTE 716)

Cancer type:

Children's cancers




Phase 3
This trial is for people who have had surgery for stage 2 melanoma. Stage 2 melanoma means that:
  • the melanoma is only in the skin
  • there is no sign that the cancer has spread to the lymph nodes or other parts of the body
It is for adults and teenagers who are at least 12 years old. We use the term ‘you’ in this summary, but if you are a parent, we are referring to your child. 

More about this trial

Surgery is the main treatment for stage 2 melanoma. Your doctors remove the cancer and a small area of healthy tissue around it. This is usually the only treatment you need. But sometimes the cancer comes back after surgery (recurrence).
Doctors would like to know whether having more treatment after surgery can stop melanoma from coming back. This is called adjuvant therapy Open a glossary item.  
In this trial, doctors are looking at the drug pembrolizumab (Keytruda). Pembrolizumab is a type of immunotherapy. It stimulates the body’s immune system Open a glossary item to fight cancer cells. 
Everyone taking part in this trial has 1 of the following after surgery:
  • pembrolizumab
  • dummy drug (placebo Open a glossary item)
The main aim of this trial is to find out whether pembrolizumab helps people with stage 2 melanoma who have had surgery.

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 stage 2B or stage 2C melanoma  
  • surgery is the only treatment you have had for melanoma 
  • you have had surgery to remove all the cancer (complete resection) in the last 3 months 
  • if you are more than 17 years old, you are well enough to carry out your normal activities, apart from heavy physical work (performance status of 0 or 1)
  • if you are less than 17 years old, you take part in quiet play and activities even if you need to lie down for much of the day (Lansky play scale of 50 or more) 
  • you have satisfactory blood test results 
  • are at least 12 years old 
  • you are willing to use reliable contraception during treatment and for at least 4 months afterwards if you are sexually active and there is any chance you or your partner could become pregnant
Who can’t take part
You cannot join this trial if any of these apply. 
Cancer related
You have had:
  • pembrolizumab or any other similar drug  
  • treatment for melanoma that reached your whole body (systemic) or radiotherapy
  • another cancer in the past 5 years apart from successfully treated non melanoma skin cancer Open a glossary item or a carcinoma in situ Open a glossary item of the cervix or breast 
Medical conditions
You can’t take part if you:
  • have had an experimental treatment in the past month 
  • have an autoimmune disease Open a glossary item that needed treatment in the past 2 weeks, apart from treatment to replace something that the body makes such as thyroxine and insulin 
  • have taken drugs that damp down your immune system (steroids) in the past 2 weeks, unless it was a very small dose, an inhaler or a cream 
  • still have side effects from surgery 
  • have had, or you currently have, lung problems such as pneumonitis Open a glossary item that needed treatment with steroids  
  • have an infection and you need antibiotics that reach your whole body 
  • have HIV
  • have hepatitis B or hepatitis C
  • have tuberculosis (TB) 
  • have had an organ transplant Open a glossary item or a bone marrow or stem cell transplant from a donor (allogeneic transplant Open a glossary item)
  • have any other medical or mental health condition that the trial team think could affect you taking part 
  • take an amount of drugs or drink an amount of alcohol that is a concern for the trial team 
You can’t take part if you:
  • are pregnant or breastfeeding  
  • are sensitive or allergic to pembrolizumab or anything it contains
  • have had a live vaccine Open a glossary item in the last month 

Trial design

This is an international phase 3 trial. Researchers hope that around 954 people worldwide will agree to take part. 
It is a randomised trial. Everyone taking part is put into 1 of the following groups by computer:
  • pembrolizumab 
  • dummy drug (placebo)
Neither you nor your doctor are able to decide which group you are in. And neither you nor your doctor will know which group you are in. This is a double blind trial
You have pembrolizumab or dummy drug as a drip into your vein every 3 weeks. It takes around 30 minutes each time. Each 3 week period is called a cycle of treatment.
You continue to have pembrolizumab or dummy drug for as long as it helps you and the side effects aren’t too bad. You have treatment for up to a year (17 treatment cycles).
If your cancer comes back during treatment, you may be able to:
  • start receiving pembrolizumab if you are in the group having the placebo (crossover treatment) 
  • have another year of pembrolizumab if you are in the group having the pembrolizumab and you have finished 17 treatment cycles of pembrolizumab more than 6 months ago (re-challenge treatment)
Your doctor can tell you more about this. 
Blood tests
You have extra blood tests as part of this trial. Researchers want to:
  • find out what happens to pembrolizumab in your body (this is called pharmacokinetics Open a glossary item)
  • look at the levels of certain proteins (biomarkers Open a glossary item) that can tell how well the treatment is working
You have the extra blood tests before the start of treatment and at set times during the trial. 
Tissue sample 
The trial team ask to use a tissue sample of your cancer taken when you were diagnosed (archival tissue sample). They may ask you to give a new sample of tissue if your cancer comes back. 
Quality of life
Everybody taking part completes a quality of life questionnaire before the start of treatment and:
  • at set times during the trial
  • at the end of treatment
  • a month after finishing treatment
  • then every 3 months for a year and every 6 months afterwards
The questionnaires ask about how you have been feeling and what side effects you have had. 

Hospital visits

You see a doctor and have some tests before taking part. These tests might include:
  • physical examination
  • heart trace (ECG Open a glossary item)
  • blood tests
  • urine test
  • a CT scan or MRI scan
During treatment, you see the trial doctor every 3 weeks. You have blood tests and a physical examination each time. You also have a CT scan or MRI scan every 6 months. 
Your treatment continues for as long as it is helping you and the side effects aren’t too bad.
When you finish treatment, you see a trial team after a month. You then see them:
  • every 3 months for a year
  • then every 6 months for 4 years
  • then every year afterwards

Side effects

The trial team monitor you during the time you have 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. 
Pembrolizumab has an effect on the immune system. This may cause inflammation in different parts of the body which can cause serious side effects such as:
  • inflammation of the lung causing breathlessness and a cough
  • Inflammation if the bowel causing diarrhoea, tummy pain and sickness

These side effects could happen during treatment, or some months after treatment has finished. In some people, these side effects could be life threatening.

The most common side effects of pembrolizumab are:

  • skin rashes, itching and changes to your skin colour
  • loose or watery poo (diarrhoea)
  • cough 
  • pain in your joints, back and tummy (abdomen)
  • thyroid problems that can cause tiredness and feeling cold 
  • low levels of salt in your body that may cause you to feel tired, have a headache and muscle cramps
We have more information about the possible side effects of pembrolizumab



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

Prof Paul Lorrigan

Supported by

Merck, Sharp & Dohme

Questions about cancer? Contact our 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.

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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