A trial of enzalutamide for prostate cancer that has a high risk of coming back (ENZARAD)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Prostate cancer




Phase 3

This trial is open to men who are due to have radiotherapy.

More about this trial

Radiotherapy Open a glossary item is one of the usual treatments for men with prostate cancer that has a high risk of coming back. 

You usually have this alongside hormone therapy to either to reduce the amount of testosterone in the body, or to block it from reaching the cancer cells. This can shrink a prostate cancer or slow its growth.

Researchers want to improve treatment for this group of men. In this trial, they are looking at a drug called enzalutamide.

Enzalutamide is a type of hormone therapy. Researchers think that having it with radiotherapy might control the cancer for longer. But they want to find out more.     

In this trial, some men have radiotherapy and enzalutamide and some have radiotherapy and usual hormone therapy treatment. 

The aims of the trial are 

  • to compare usual treatment with enzalutamide to see which works best
  • to learn more about the 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 might be able to join this trial if all of the following apply. 

  • You have adenocarcinoma Open a glossary item of the prostate that has a high risk of coming back. This means one of the following applies. You have
    • a gleason score Open a glossary item of 8 to 10
    • a gleason score of 4+3, the cancer is contained within the prostate gland or has grown into surrounding tissue (stage T2b to stage T4) and you have a PSA blood test result of more than 20
    • cancer cells in nearby lymph nodes in the lower pelvis (the area between your hip bones) (stage N1)​
  • Your treatment is planned and you are able to start within 7 days of being put into a treatment group
  • You completed the quality of life questionnaire before starting treatment unless you have limited vision or you have reading difficulties
  • You have satisfactory blood test results
  • You are well enough to carry out all your normal activities, apart from heavy physical work (performance status 0 or 1)
  • You are willing to use reliable contraception during the trial if there is any chance that your partner could become pregnant 
  • You are at least 18 years old

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

  • Have cancer that has spread to another part of the body
  • Have a large number of cells called sarcomatoid, spindle cell or neuroendocrine small cells in your tissue sample (biopsy Open a glossary item)  
  • Have cancer cells in the lymph nodes Open a glossary item in the upper part of the pelvis or outside the pelvis 
  • Can’t have external beam radiotherapy for any reason 
  • Have a PSA blood test result that is more than 100
  • Are having hormone therapy including a type called an anti androgen such as flutamide or enzalutamide. You might be able to take part if you have had a type of hormone therapy called a luteinising hormone blocker such as goserelin for less than 30 days before joining this trial.
  • Have had surgery to remove both testicles (an orchidectomy) or you have had surgery to remove the prostate gland
  • Have had internal radiotherapy (brachytherapy Open a glossary item) or external radiotherapy that would result in the area where you due to have radiotherapy overlapping
  • Have had major surgery in the last 21 days
  • Have had any other treatment as part of a clinical trial
  • Have had any other cancer in the last 5 years apart from non melanoma skin cancer Open a glossary item or very early bladder cancer that was successfully treated
  • Have HIV unless it is well controlled with medication that won’t be affected by enzalutamide
  • Have any condition that means you could have fits (seizures) or you have experienced seizures in the past
  • Have blacked out or had a mini stroke (TIA) in the last year
  • Have had a serious heart problem in the last 3 months such as a heart attack, an abnormal heart rhythm, a stroke or a condition called atrial fibrillation unless you are taking medicine to prevent clotting 
  • Have a severe infection that needs treatment
  • Have a problem with your digestive system that would affect how the trial drug is absorbed
  • Have a problem with swallowing tablets
  • Have a problem with drugs and alcohol
  • Have any other serious medical condition or mental health problem that the study team think could affect you taking part

Trial design

This is an international phase 3 trial. The researchers need 800 men including 100 from the UK to take part. 

It is a randomised trial. You are put into treatment groups by a computer. Neither you nor your doctor can decide which group you are in. 

  • one group have enzalutamide, radiotherapy and hormone therapy injections
  • the other group have usual hormone therapy, radiotherapy and hormone therapy injections

Diagram showing ENZARAD randomisation

In the usual treatment group, you have hormone therapy such as bicalutamide, nilutamide or flutamide. These are either tablets or capsules. How often you take them depends on the type you are having. Your doctor can tell you more about this. You have treatment for up to 6 months

All the men taking part also have 

  • radiotherapy and 
  • hormone therapy injections

You begin radiotherapy 4 months after starting hormone therapy. You have treatment every week day (Monday to Friday) for 8 weeks. Each treatment takes about 10 to 15 minutes.

You have hormone therapy injections such as goserelin or leuprorelin. You have the injections under the skin or into a muscle every 3 months. 

Tissue and blood samples
The researchers will ask for sample of your cancer that was removed when you had a biopsy Open a glossary item. They will also ask you if can give some extra blood tests. 

The researchers want to look for substances called biomarkers Open a glossary item to find out why treatment might work for some people and not for others. If you don’t want to donate these samples for research, you don’t have to. You can still take part in the trial.

Quality of life
Everybody taking part will be asked to fill out a questionnaire before starting treatment, at set times during the trial and after finishing treatment. The questionnaire will ask about any side effects you have had and about how you have been feeling. This is called a quality of life study

Hospital visits

You see the doctor and have some tests before taking part in the trial. These include 

You go to hospital 5 days a week, Monday to Friday to have radiotherapy. 

When you finish all treatment you see the trials team a month later for a check up. They will repeat some of the tests you had at the beginning of the trial. After that you see them every 

  • 3 months for 2 years
  • 4 months for years 3 and 4
  • 6 months in years 5 and 6 
  • 12 months

Side effects

The most common side effects of enzalutamide are

  • feeling or being sick
  • diarrhoea or constipation
  • loss of appetite
  • muscle pain, weakness and joint pain
  • headache
  • cold like symptoms
  • tiredness (fatigue)
  • swelling in your feet and legs
  • shortness of breath
  • hot flushes
  • losing weight or putting on weight
  • a drop in red blood cells (anaemia)
  • a drop in white blood cells causing an increased risk of infection
  • loss of sex drive (libido) and erections (impotence)

We have information about 

Your doctor will talk to you about the side effects of all treatment in this trial before you agree to take part. 

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 Paul Kelly 

Supported by

Astellas Pharma
Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP)
Cancer Trials Ireland
NHMRC Clinical Trials Centre, University of Sydney

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.”

Last reviewed:

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