A trial looking at enzalutamide and Ra223 for men with prostate cancer (PEACE III)

Cancer type:

Prostate cancer




Phase 3

This trial is for men with prostate cancer that has spread to the bones (advanced cancer). It is for men with 4 or more areas of cancer in the bones. 

More about this trial

Prostate cancer can be treated with hormone therapy. But after some time, it can spread to the bones. This is castration resistant prostate cancer.

If this happens, you can have more hormone therapy. Often with a drug called enzalutamide (also called Xtandi).

Researchers are looking at new ways of helping men in this situation. In this trial, they are looking at radium 223 (Ra223 also called Xofigo).             

Ra223 is already used to treat cancers that have spread to the bones. But doctors want to find out if having it with enzalutamide is better.

Ra223 is a type of internal radiotherapy. Bone cells take up the radium 223 and once it’s in the bones, it releases radiation.  

In this trial, people have 1 of the following:

  • enzalutamide
  • enzalutamide with Ra223

The main aims of this trial are to:

  • find out how well enzalutamide with Ra223 work as a treatment
  • learn about the side effects of enzalutamide with Ra223
  • learn how well people cope with the treatment and side effects  

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.

You may be able to join this trial if all of the following apply.

  • You have adenocarcinoma of the prostate (prostate cancer) that has spread to the bones
  • You have 4 or more areas of cancer in the bones and this has been confirmed by a CT scan or MRI scan
  • You take medicines to prevent fractures and strengthen the bones
  • Your cancer is causing no pain or only mild pain (and you aren’t taking strong painkillers such as opioids)
  • Your PSA level and scans show that your cancer is getting worse
  • You take drugs to lower the levels of the male hormone testosterone such as Zoladex or have had both your testicles removed (orchidectomy)
  • You have very low levels of testosterone (less than 50 ng/dL)
  • You have satisfactory blood tests results
  • Your heart is working well
  • You are able to swallow and absorb tablets
  • You are well enough to carry out your normal activities, apart from heavy physical work (performance status of 0 or 1)
  • You are at least 18 years old
  • You are willing to use reliable contraception during treatment and for 3 months after the final dose of enzalutamide or for 6 months after the last dose of Ra223 if there is any possibility your partner could become pregnant.

You cannot join this trial if any of these apply.

  • Your cancer has spread to internal organs (such as lungs and liver), the brain, spinal cord or the tissues that surround the brain (carcinomatous meningitis)
  • You have had another cancer in the past 3 years apart from basal cell skin cancer, squamous cell skin cancer or an early cancer (carcinoma in situ) of the bladder that has been successfully treated
  • You have had a type of external radiotherapy to help with pain from cancer that has spread to the bones (hemibody radiotherapy). You may be able to take part if you had any other type of external radiotherapy and you don’t have side effects from it
  • You have had treatment with enzalutamide, Ra223 or with any other radioactive drugs (such as strontium-89)
  • You have had docetaxel or abiraterone for castration resistant prostate cancer
  • You have had drugs that affect certain proteins called cyp17 (such as abiraterone), drugs to treat fungal infections (such as ketoconazole) or drugs that affect your heart (such as clarithromycin and chlorpromazine)
  • You have had drugs that block the effect of testosterone (such as bicalutamide or flutamide) is the past 48 hours
  • You take a high dose of corticosteroids such as prednisolone  
  • You have had an experimental drug as part of a clinical trial in the past 4 weeks
  • You have osteonecrosis of the jaw
  • You have had a major surgery in the past 4 weeks
  • You have had a fit (seizure), loss of consciousness, a transient ischemic attack (TIA) or any other condition that makes you at risk of having a fit (such as stroke or head trauma) in the past 12 months
  • You have had heart problems such as congestive heart failure, high or low blood pressure and problems with your heart rhythm (arrhythmias and bradycardia) that are not controlled by medication, a heart attack in the past 6 months, angina that is not controlled in the past 3 months or you have a pacemaker
  • You have a serious medical condition such as an infection that needs antibiotics, inflammation of the bowel (ulcerative colitis or Crohn’s disease), problems with your bone marrow, a condition that affects the way you absorb tablets (such as active peptic ulcer) or you have a problem controlling your bowels (faecal incontinence) 
  • You are known to be sensitive to enzalutamide, Ra223 or anything they contain
  • You have any other serious medical condition or mental health problem that the trial team think could affect you taking part
  • You take drugs or drink an amount of alcohol that is a concern for your doctors   

Trial design

This is an international phase 3 trial. The researchers need about 560 people to take part worldwide. And hope that around 53 people from the UK will take part.

This trial is randomised. The people taking part are put into 1 of the following groups by a computer:

  • enzalutamide
  • enzalutamide with Ra223

Neither you nor your doctor will be able to decide which group you are in. 

Diagram for PEACE III

You have enzalutamide as capsules. You have 4 capsules every day, once a day.

You continue to have enzalutamide for as long as it is helping you and the side effects aren’t too bad.

If your cancer gets worse, you may be able to continue to have enzalutamide for another 3 months. Your doctor can tell you more about this.

Enzalutamide with Ra223
You have Ra223 as an injection into a vein. It takes about 5 minutes. The dose you have depends on your weight. You have it once a month, for 6 months.

You have enzalutamide as capsules. You take 4 capsules once every day.

You continue to have enzalutamide and Ra223 for as long as it is helping you and the side effects aren’t too bad.

If your cancer gets worse, you may be able to continue to have enzalutamide for another 3 months. Your doctor can tell you more about this.

Samples for research  
Doctors may ask you to have some extra blood and urine tests as part of this trial. The researchers want to look for substances called biomarkers to see why treatments work better for some people than others.

You have the extra blood and urine tests before the start of treatment and then:

  • after 3 months
  • after 4 months
  • if your cancer gets worse

You don’t have to agree to have the extra blood and urine tests if you don’t want to. You can still take part in this trial.

You complete 2 separate questionnaires:

  • before starting treatment
  • every 12 weeks during treatment
  • after you finish treatment
  • if your cancer gets worse

They ask about how you have been feeling, what side effects you have had, if you have any pain and how you manage day to day. They take about 20 minutes to complete. 

Hospital visits

You see a doctor and have some tests before taking part. These tests might include:

During treatment you see the trial doctors every 4 weeks and have a physical examination and blood tests.  

You have a bone scan and a CT or MRI scan every 12 weeks to see what is happening with your cancer. You might also have an x-ray.

After you finish the trial treatment you see the doctors and have some tests. These tests may include:

  • blood tests
  • a physical examination
  • a bone scan
  • an x-ray
  • a CT or MRI scan

Your trial doctor or nurse will then phone you to see how you are.

If your cancer stays the same but you stop having treatment for other reasons, you continue to see the trial doctor regularly. Your doctors will tell you how often they need to see you as this depends on why you stopped the trial treatment. You have a bone scan every 12 weeks. You may also have x-rays and a CT scan or MRI scan.  

Side effects

The trial team monitor you during the time you have treatment and you will be given 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 trial.

The most common side effects of Ra223 are:

  • feeling or being sick
  • diarrhoea
  • a drop in the number of cells that help the blood to clot (platelets), causing an increased risk of bleeding

We have more information on Ra223.   

We also have information on enzalutamide



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

Dr Santhanam Sundar 

Supported by

Astellas Pharma
Bayer HealthCare AG
European Organization for Research and Treatment of Cancer (EORTC)
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer

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.

Keith took part in a trial looking into hormone therapy

A picture of Keith

"Health wise I am feeling great. I am a big supporter of trials - it allows new treatments and drugs to be brought in.”

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