A trial of MDV3100 for prostate cancer that has spread and is not responding to hormone therapy (PREVAIL)

Who can enter

You can enter this trial if you

• Have prostate cancer that has spread to other parts of your body and is getting worse despite hormone therapy
• Have no symptoms, or only mild symptoms from your cancer
• Are taking hormone therapy to lower your testosterone levels, or have had surgery to remove your testicles (an orchidectomy)
• Have satisfactory blood test results
• Are well enough to carry out all your normal activities, apart from heavy physical work (performance status of 0 or 1)

You cannot enter this trial if you

• Have cancer that has spread to your brain
• Have already had chemotherapy for prostate cancer
• Have ever had radiotherapy to other areas of the body where the cancer has spread
• Are taking drugs called bisphosphonates unless you have been on the same dose for at least 4 weeks
• Have had major surgery in the last 4 weeks
• Have had a drug called ketoconazole and your prostate cancer got worse during this treatment
• Have had flutamide, cyproterone, oestrogen, or drugs such as finasteride or dutasteride in the last 4 weeks
• Have had drugs called bicalutamide or nilutamide in the last 6 weeks
• Have needed to take strong painkillers called opioids, such as morphine, in the last 4 weeks for cancer pain
• Have taken herbal products in the last 4 weeks that may reduce PSA levels such as Saw Palmetto
• Have taken steroids in the last 4 weeks, unless it is a low dose
• Have had another cancer in the last 5 years apart from non melanoma skin cancer that has been successfully treated
• Have high blood pressure that cannot be controlled with medication
• Have had a heart attack in the last 6 months, heart pain (angina) in the last 3 months, or have another heart condition that is a cause for concern
• Have any condition that could affect you swallowing or absorbing capsules or any other serious medical condition that the trial doctors think could affect you taking part in this trial

Trial design

This is an international phase 3 trial. It will recruit about 1,680 men in a number of different countries.

It is a randomised trial. The men taking part are put into treatment groups by computer. Neither you nor your doctor will be able to decide which group you are in. And neither of you will know which group you are in. This is called a ‘double blind trial’.

• Men in 1 group take 4 MDV3100 capsules once a day
• Men in the other group take 4 capsules of a dummy drug (placebo) once a day

As long as you don’t have bad side effects, you can carry on taking the capsules for as long as they help you.

At the beginning of the trial, you will be asked to fill in a questionnaire which asks about the pain you have from your prostate cancer. You fill this in again after 3 months and 6 months. The trial team will also ask you to fill out some other questionnaires during the trial. These will ask about any side effects you have had and how you have been feeling. This is called a quality of life study.

The trial team will ask you to have a number of scans to help them see if your prostate cancer is getting worse.

The researchers will take a number of blood samples throughout the trial. They will use some of these samples to study the way MDV3100 works in the body. This is called pharmacokinetics.

They will also ask your permission to take an extra blood sample in the first week of treatment. They will use this to learn more about how genes affect the way people respond to the drug and the side effects they have. This is called pharmacogenetics. If you don’t want to give a blood sample for this part of the study, you don’t have to. You can still take part in the trial.

Hospital visits

Before you start the study treatment, you see the trial doctors and have some tests. The tests include

• Physical examination
• Blood and urine tests
• Heart trace (ECG)
• Chest X-ray
• CT scan or MRI scan
• Bone scan

You go to hospital once every 4 weeks for nearly 6 months. After that, the trial team will need to see how you are each month, but they can do some of these assessments by phone.

After about a year of treatment, your hospital visits reduce to once every 3 months. When you finish the trial treatment, you go back and see the trial doctors 4 weeks later. The trial team will then check to see how you are getting on every 3 months. For most people, this will be by phone.

You have an ECG and blood tests at each hospital visit. You have a bone scan and CT or MRI scan after 8 weeks of treatment. Depending on the results of these scans, the doctors will tell you if need to have more scans later on.

Side effects

MDV3100 is a new drug, so there may be side effects doctors don’t know about yet. From earlier trials, they know the side effects include

• Tiredness (fatigue)
• Sickness
• Loss of appetite
• Constipation
• Back pain or joint pain

As MDV3100 blocks the action of testosterone, it is likely to cause infertility and impotence. It may also cause hot flushes and changes to your muscles and bones. But if you are taking part in this trial, you will have already had drugs that lower or block male sex hormones, so you may not notice any further changes.