A trial of GDC-0068 with abiraterone for prostate cancer that is no longer responding to hormone therapy

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

Cancer type:

Prostate cancer




Phase 2

This trial is looking at a drug called GDC-0068 alongside abiraterone for prostate cancer that has stopped responding to hormone therapy. The trial is for men with prostate cancer that has got worse despite having docetaxel chemotherapy.

Doctors often treat prostate cancer with hormone therapy. This can keep the cancer under control for a long time. But at some point, it may start growing again. If this happens, you can have a chemotherapy drug called docetaxel. If the cancer continues to grow or comes back after docetaxel, you may have a drug called abiraterone. But researchers are looking for ways to improve treatment and in this trial they are looking at a drug called GDC-0068.

GDC-0068 blocks the action of a protein called AKT. This may stop cancer cells growing. The aims of the trial are to

  • See if GDC-0068 alongside abiraterone helps men with prostate cancer that is no longer responding to hormone therapy
  • Learn more about the side effects

Who can enter

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

  • Have prostate cancer that has spread outside your prostate gland and got worse during hormone therapy
  • Have already had docetaxel chemotherapy
  • Have had blood tests since your last treatment that show the level of PSA in your blood is rising
  • Have been having hormone therapy that has reduced the amount of testosterone Open a glossary item in your body to a very low level
  • Are well enough to carry out all your normal activities, apart from heavy physical work (performance status of 0 or 1)
  • Have satisfactory blood test results
  • Are at least 18 years old
  • Are willing to use a reliable form of contraception during the trial and for 6 months afterwards if you are sexually active and there is any chance your partner could become pregnant

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

  • Have a type of prostate cancer called small cell cancer or a neuroendocrine tumour
  • Have had chemotherapy, biological therapy  or hormone therapy in the last 2 weeks (if you have been having hormone therapy to lower the amount of testosterone in your body, you can take part)
  • Have had radiotherapy in the last 2 weeks (unless it was radiotherapy to your bones to treat symptoms of cancer spread)
  • Have had an experimental drug as part of another trial in the last 4 weeks
  • Have already had abiraterone or a drug that works in the same way
  • Have already had a drug that works in a similar way to GDC-0068
  • Haven’t recovered from the side effects of other treatment apart from hair loss or nerve damage (peripheral neuropathy) if it is only mild
  • Have had any other cancer in the last 5 years apart from bladder cancer if it is only in the lining of the bladder (non invasive bladder cancer) or non melanoma skin cancer that was successfully treated
  • Have diabetes Open a glossary item and need to take insulin (you may be able to take part if your diabetes is controlled with tablets, as long as you’ve been having the same dose for at least 4 weeks)
  • Can’t swallow or absorb tablets for any reason
  • Need to use oxygen to be able to carry out your normal daily activities
  • Need to take steroids Open a glossary item each day, unless it is a low dose (the trial team can advise you about this)
  • Have an infection that needs treatment with antibiotics through a drip
  • Have an autoimmune disease Open a glossary item that isn’t controlled with non steroidal anti inflammatory drugs
  • Have a condition needing treatment with medication that damps down your immune system Open a glossary item
  • Have had a heart attack in the last 6 months or have certain other heart problems (the trial team can advise you about this)
  • Have hepatitis or other problems with your liver (the trial team can advise you about this)
  • Have had problems with your adrenal glands Open a glossary item
  • Have had a serious injury or major surgery in the last 4 weeks
  • Are known to be HIV positive
  • Have any other medical condition that the trial team think would make it unsafe for you to take part or could affect the results of the trial

Trial design

This is a phase 2 trial. The researchers need about 240 men to join. It is a randomised trial. The people taking part are put into 1 of 3 treatment groups by a 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 group 1 have abiraterone and GDC-0068
  • Men in group 2 have abiraterone and a lower dose of GDC-0068
  • Men in group 3 have abiraterone and a dummy drug (placebo Open a glossary item)

trial diagram

You take both abiraterone and GDC-0068 (or the dummy drug) as tablets every day. You also take a steroid drug called prednisolone each day. This is to reduce some of the side effects of abiraterone.

The trial team will tell you how and when to take the tablets. They will give you a diary to keep at home. In this, you write down the time you take the tablets each day.

The trial team will ask you to fill out a questionnaire before you start treatment, every 4 weeks during treatment and after you finish treatment. The questionnaire will ask about side effects and how you’ve been feeling.  This is called a quality of life study.

For the first 3 months of the trial, they will also ask you to fill in a diary every day to record whether you have any pain.

As long as you don’t have bad side effects and your cancer doesn’t get worse, you can carry on having treatment in this trial for up to 2 years.

If you have to stop one of the drugs because of bad side effects, you may be able to carry on taking the other one on its own. Your doctor will discuss this with you.

Hospital visits

You will see the trial team and have some tests before you start treatment. The tests include

  • Physical examination
  • Heart trace (ECG Open a glossary item)
  • Heart scan (echocardiogram Open a glossary item) or MUGA scan Open a glossary item
  • CT scan or MRI scan (unless you’ve had one of these in the last 4 weeks)
  • Bone scan
  • Blood tests
  • Urine test

The trial team need to get a sample of your cancer that was removed when you had a biopsy Open a glossary item in the past. If there is not a sample available, you will need to have a new biopsy.

You see the trial team 3 times in the first 4 weeks of treatment, twice in the 2nd 4 weeks, and then once every 4 weeks after that. You have regular blood tests and more ECGs.

You have a bone scan and a CT or MRI scan 4 times in the first 9 months of treatment and then every 3 months after that.

When you finish treatment, you see the trial team again a month later. They will then phone you every 3 months to see how you are.

If you stop treatment for any reason other than your cancer getting worse, your doctor will ask you to carry on having scans every 3 months until your cancer does start to get worse, or you start another treatment.

Side effects

As GDC-0068 is a new drug, and this is the first time it is being used alongside abiraterone, there may be side effects we don’t know about yet. In trials looking at GDC-0068 alone, the most common side effects have been

Read more information about the side effects of abiraterone.

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

Professor Johann De Bono

Supported by

Experimental Cancer Medicine Centre (ECMC)
Genentech Ltd
NIHR Clinical Research Network: Cancer

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 9719

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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