A trial looking at adding pembrolizumab to other cancer treatments for people with prostate cancer that has spread (KEYNOTE-365)

Please note there are several treatment groups so the entry conditions for this trial are complex. Each group has specific entry conditions and we haven’t listed them all. Some groups are closed now.

The trial team will check if you are suitable to join the trial and which group you might join. They can tell you more about this.

Your doctor decides which group is best for you. To help them decide, they look at:

• what type of treatment you have already had
• the type of cells in your cancer – this is either adenocarcinoma or neuroendocrine cancer that has developed after previous treatment (treatment emergent neuroendocrine cancer)
• what they think would be the best treatment for you
• your medical history

The following bullet points are a summary of the main 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 prostate cancer that has spread to other parts of the body and got worse despite having hormone treatment (metastatic castration resistant prostate cancer)
• have prostate cancer which has been getting worse (progressed) within the 6 months before joining the trial
• have a cancer tissue sample from an area where you have not had radiotherapy before. Or you have a sample from an area where you have had radiotherapy before - but your cancer is growing again in the same place.
• are receiving treatment to lower the amount of male sex hormones in your body (androgen deprivation). Your treatment must have started at least 4 weeks before the first dose of the study drug. Or you have had surgery to remove the testicles (orchidectomy).
• have adequate blood tests results including testosterone level.
• are willing to use reliable contraception if there is a chance your partner could become pregnant. The exact timing depends on which group you are in.
• are at least 18 years old

Who can’t take part

Cancer related

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

• are still experiencing significant side effects from having major surgery or from other cancer treatment you have had in the past
• have had another cancer within the past 3 years that has been getting worse, or needed treatment – apart from basal cell skin cancer  or squamous cell skin cancer that have been treated with the aim to cure
• have had certain monoclonal antibody treatments within the 4 weeks before starting treatment on this trial. You might still be able to take part if you are taking denosumab for cancer that has spread to the bone. Your doctor can explain more.
• have had certain monoclonal antibodies more than 4 weeks before starting the study drug, but you have still not recovered from their side effects
• have had radium therapy for your prostate cancer or any other types of radioisotope treatment for your prostate cancer
• have had pembrolizumab before or had any very similar drugs to pembrolizumab in the past. Your doctor can explain more.
• have cancer that has spread to the central nervous system  (CNS). You may be able to take part if you have had treatment in the past for cancer that has spread to the CNS and it is now stable. Your doctor will explain more.
• have cancer that has spread to the leptomeningeal layers of the central nervous system 
• have had chemotherapy, targeted cancer drugs, certain types of hormone therapy or radiotherapy in the 2 weeks before the first dose of the study drug. Your doctor can explain more.
• have had a bone scan called a ‘superscan’. Your doctor can explain more.
• have been taking bone strengthening drugs, for example bisphosphonates, for 4 weeks or less before the first dose of the study drug

Medical conditions
You cannot join this trial if any of these apply. You:

• have an immune deficiency . Or you have been taking long term steroids that reach your whole body or other drugs that lower your immune system in the 7 days before your trial treatment is decided.
• have an active autoimmune disease which has required systemic treatment  in the past 2 years. You can still take part if you take replacement therapy, such as insulin or steroids, if your body does not make enough. Your doctor can explain more.
• have inflammation of the lung tissue (pneumonitis) or if you have had pneumonitis which needed steroid treatment before
• have an infection needing treatment that reaches the whole body
• have any other medical problem, mental health condition or are taking any medication that the trial team think would affect you taking part
• have HIV
• have active hepatitis B or hepatitis C
• have had an organ transplant or bone marrow transplant  in the past

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

• have had a live vaccine  within 30 days before the first dose of the study drug
• have taken any herbal medicines that may have affect prostate hormones or are known to decrease prostate specific antigen  levels (such as saw palmetto, ginko or turmeric) within the 4 weeks before your treatment group is decided
• have had another trial drug or used a healthcare product as part of another clinical trial or study in the 4 weeks before the first dose of the study drug

As well as the above there are specific entry conditions and exclusion criteria for each treatment group. Speak to your doctor or research nurse if you want to find out more about the entry conditions for this trial.