A trial looking at whether ctDNA can help doctors know who is at risk of breast cancer coming back and if pembrolizumab reduces ctDNA (c-TRAK TN)

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 early stage triple negative breast cancer (TNBC)
• your doctor thinks that there is a high or moderate risk of your cancer coming back
• you have samples of tissue taken during a biopsy  to diagnose your cancer or during breast cancer surgery that can be given to the study team
• you have had surgery or chemotherapy in the last 3 months, or you have finished radiotherapy in the past 6 weeks
• you are well enough to be up and about for at least half the day (performance status 0, 1 or 2)
• you have satisfactory blood tests
• you are willing and able to have blood samples taken for research
• you are willing to receive pembrolizumab treatment, if you are randomised  to do so
• you are at least 16 years old
• you are willing to use reliable contraception during treatment and for 4 months after the last dose of pembrolizumab (if you have this), if there is any possibility 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 breast cancer that has spread to other parts of the body (metastatic)  
• are having, or are going to have, treatment for breast cancer apart from surgery, or radiotherapy and chemotherapy given in addition to surgery (adjuvant treatment )
• have had treatment with a targeted cancer drug (biological therapy) in the last 4 weeks
• have had pembrolizumab before or any other similar drug
• have had another cancer in the last 5 years apart from basal cell skin cancer or carcinoma in situ  of the cervix that have been successfully treated 

Medical conditions
You:

• are taking part in another clinical trial, or have taken part in a clinical trial that continued after your breast cancer surgery  
• have had an experimental treatment in the past month
• have or have had an autoimmune disease  that needed treatment that reached your whole body (systemic treatment) in the past 2 years, apart from treatment to replace something the body makes such as insulin or thyroxine
• have taken drugs that damp down your immune system (immunosuppressants) such as steroids in the week prior to the start of treatment
• have moderate or severe side effects from previous treatment, apart from hair loss (alopecia) or problems with your nerves (neuropathy), that have not recovered before the start of treatment 
• have lung problems such as inflammation of the lungs (pneumonitis)
• have tuberculosis
• have HIV
• have hepatitis B or hepatitis C
• have an active infection
• have had an organ transplant  or allogenic stem cell transplant  in the past 
• have any other medical condition that the trial team thinks could affect you taking part

Other
You:

• are pregnant or breastfeeding
• have had a live vaccine in the past month (prior to the start of treatment)