A trial looking at pembrolizumab for men with prostate cancer (KEYNOTE-199)

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 you are a man and all of the following apply

• You have adenocarcinoma of the prostate (prostate cancer)
• Your cancer has grown into surrounding tissue and cannot be removed with surgery, or has spread to another part of your body (metastatic cancer) 
• You have an area of prostate cancer that can be seen and measured on a scan or areas of cancer in your bones (bone metastases ) that can be seen on a scan  
• You are not able to have any treatment to cure your cancer
• Your PSA and scans show that your cancer is getting worse in the past 6 months 
• You have had a sample of cancer taken (a biopsy ) or are willing to have 1 taken – the doctor will check for this 
• You have had at least 1 type of hormone treatment to reduce the level of testosterone  (such as abiraterone or enzalutamide)
• You have had treatment with a chemotherapy drug called docetaxel or a hormone therapy called enzalutamide
• You have very low levels of the male hormone testosterone (less than 50 ng/dL). If you haven’t had surgery to remove the testicles (orchidectomy) and are taking drugs to stop the testicles making testosterone you must have started them at least 4 weeks ago
• You are well enough to be up and about for at least half of the day (performance status of 0, 1 or 2)
• You have satisfactory blood tests results
• You are at least 18 years old
• You are willing to use reliable contraception during treatment and for 120 days (about 4 months) after the final dose of pembrolizumab if there is any possibility your partner could become pregnant

You cannot join this trial if any of these apply:

• You have a rare type of prostate cancer called small cell prostate cancer  
• Your cancer has spread to your brain or the tissues surrounding your brain (carcinomatous meningitis). If your cancer has spread to your brain and you have had treatment for this, you may be able to take part if it is stable, you have no symptoms and you have not had steroids in the past 7 days  
• You have had another cancer in the last 3 years apart from basal cell skin cancer , squamous cell skin cancer or carcinoma in situ (CIS) of the cervix that has been successfully treated
• You have had radiotherapy, hormone therapy or chemotherapy in the past 2 weeks (4 weeks if it was a monoclonal antibody)
• You have had more than 2 different types of chemotherapy or more than 3 if it was a combination of chemotherapy and hormone therapy     
• You have had the drug pembrolizumab or any other drug that affects a protein called PD-1 or certain immune cells called T-cells 
• You have had an experimental drug or used an experimental device as part of a clinical trial in the past 4 weeks
• You have moderate to severe side effects from previous anti cancer treatments (apart from hair loss and numbness and tingling in your hands and feet)
• You take drugs to stop or slow down bone damage (such as bisphosphonates ) and have not been on a stable dose in the past 4 weeks   
• You have inflammation of the lungs (pneumonitis) that needs treatment with steroids or a lung condition called interstitial lung disease
• You have a problem with your immune system  and have taken drugs to damp it down (immunosuppressants) such as steroids in the past 7 days (unless it was a small dose to help with your symptoms) 
• You have an autoimmune disease that needed treatment that reached your whole body (systemic treatment ) in the past 2 years, unless it was treatment to replace something the body makes such as thyroxin and insulin      
• You have an active infection
• You have HIV
• You have hepatitis B or hepatitis C
• You have had a live vaccination  in the past 30 days
• You have any other serious medical condition or mental health problem that the trial team think could affect you taking part