Radiotherapy in combination with pembrolizumab in patients with PSA persistence or biochemical recurrence after radical prostatectomy due to prostate cancer - Pembro-SRT
After surgery to remove the prostate, doctors track a protein in the blood called PSA (prostate-specific antigen). If PSA levels do not drop fully or start to rise again, it suggests some cancer cells may still be present. This is known as biochemical recurrence. Standard care often involves radiotherapy directed at the prostate area. This clinical trial, called Pembro-SRT, is testing whether adding an immunotherapy drug called pembrolizumab (Keytruda) to radiotherapy works better than radiotherapy alone. Pembrolizumab helps your own immune system recognise and destroy cancer cells. The main aim is to check if this combination can lower PSA levels until they can no longer be detected after 60 weeks. Researchers will also monitor overall health, quality of life, and scan results to see if the treatment stops the cancer from spreading.
At a glance
What is this study about?
For many men with localised prostate cancer, having an operation to remove the prostate gland (a radical prostatectomy) is a successful treatment. However, in some cases, tiny prostate cancer cells remain behind. Doctors detect this through regular blood tests measuring prostate-specific antigen (PSA). When PSA stays detectable or begins to creep up after surgery, doctors call it PSA persistence or biochemical recurrence.
The usual next step is salvage radiotherapy, which aims radiation beams at the pelvis to destroy any lingering cells. In this trial, researchers are testing whether adding an immunotherapy medicine called pembrolizumab makes radiotherapy more powerful. Pembrolizumab works by taking the 'brakes' off your body's immune system, allowing your white blood cells to hunt down and attack cancer cells.
This trial matters because finding more effective ways to clear cancer early on could stop it from spreading to other areas, such as the bones. If successful, this combination could help men stay cancer-free for longer and potentially delay or avoid long-term hormone therapy, which often comes with unwanted side effects.
Key takeaways
- Tests adding pembrolizumab immunotherapy to radiotherapy for recurrent prostate cancer.
- Aimed at men whose PSA is rising or still detectable after prostate removal surgery.
- The primary goal is to achieve an undetectable PSA level at 60 weeks.
- Requires regular hospital visits for infusions, scans, and blood tests.
- Participation is entirely voluntary and does not impact your right to standard treatment.
Who may be eligible?
This trial is open to adult men aged 18 and over who have previously had surgery to remove their prostate gland because of prostate cancer.
To be considered, your routine blood tests must show that your PSA level has either not dropped to zero as expected after your operation, or has started rising again after previously falling. This suggests that some microscopic cancer cells may still be present.
Men who take part will need to be fit enough to receive both radiotherapy and immunotherapy. Your doctor or the study team will carry out health checks and scans to ensure it is safe for you to join.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- I am a man aged 18 or older.
- I have had surgery (radical prostatectomy) to remove my prostate cancer.
- My recent blood tests show my PSA level is rising or has not completely cleared.
- I am well enough to attend hospital visits for radiotherapy and drip infusions.
- I am interested in taking part in a clinical trial.
What does participation involve?
Taking part involves receiving salvage radiotherapy alongside regular doses of pembrolizumab. Pembrolizumab is given as a liquid through a drip into a vein (an intravenous infusion), usually taking around 30 minutes per session at the hospital clinic. Depending on your individual risk level, some men may also receive standard hormone therapy (androgen deprivation therapy).
Throughout the study, you will have regular hospital appointments for blood tests to monitor your PSA levels and general organ function. You will also have periodic imaging scans to check that the cancer has not spread. In addition, you will be asked to fill out quality-of-life questionnaires (FACT-P) to track how you are feeling day-to-day. The main treatment and assessment period lasts for roughly 60 weeks, followed by further monitoring visits.
Potential risks and benefits
Locations (1)
- —UnverifiedGermany
Common questions
What is pembrolizumab?
Pembrolizumab (brand name Keytruda) is a type of immunotherapy. It helps your own immune system find and fight cancer cells.
What is biochemical recurrence?
It means your PSA blood levels have started rising after surgery, indicating that a small number of cancer cells may still be active, even if nothing shows up on scans yet.
How is the trial medicine given?
Pembrolizumab is given as an infusion through a small tube into a vein in your arm, usually at a hospital day unit.
Will I still get radiotherapy?
Yes. Radiotherapy to the prostate area is a core part of the treatment programme in this trial.
Can I leave the study if I change my mind?
Yes. You are free to leave the trial at any point without giving a reason, and your doctors will continue to provide standard NHS care.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
Discussion
Community discussion
Powered by our forum at community.patient.info. Please be respectful — this is not medical advice.