A study of rucaparib in advanced prostate cancer (TRITON3)

Cancer type:

Prostate cancer

Status:

Open

Phase:

Phase 3
This trial is for men who have prostate cancer that has spread and has got worse despite having hormone treatment (castration resistant prostate cancer).
 
Doctors usually treat advanced prostate cancer with hormone therapy Open a glossary item and chemotherapy Open a glossary item.
 
These can work well for a period of time, but the cancer can start to grow again. Doctors are working on new treatments for when other treatments have stopped working. 
 
This trial is comparing a drug called rucaparib (or CO-338) to standard prostate cancer treatments. These standard treatments are:
  • abiraterone
  • enzalutamide
  • docetaxel 

More about this trial

Rucaparib has been looked at in women with ovarian cancer but not yet in patients with prostate cancer. It is a type of targeted cancer drug known as a PARP inhibitor. PARP is a protein that helps damaged cells repair themselves. If PARP is blocked, then cancer cells might not be able to repair themselves.
 
Cancer cells with certain gene changes (mutations Open a glossary item) already have problems repairing themselves. We know from research that PARP inhibitors might help men whose prostate cancer cells have mutations including:
  • BRCA1 (breast cancer susceptibility gene 1) 
  • BRCA2 (breast cancer susceptibility gene 2) 
  • ATM (ataxia telangiectasia mutated serine gene) 
The researchers hope that by blocking PARP, cancer cells with these mutations won’t be able to repair themselves and will die. 
 
The trial aims to:
  • understand how rucaparib works when compared to standard treatments in advanced prostate cancer with a BRCA or ATM genetic change (mutation) 
  • look for substances called biomarkers Open a glossary item to find out which men with prostate cancer might benefit most from rucaparib
  • learn more about the side effects 
  • find out more about quality of life Open a glossary item

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. 
 
Who can take part
 
You may be able to join this trial if all of the following apply. You:
  • have a type of prostate cancer called adenocarcinoma Open a glossary itemor prostate cancer cells that look very abnormal under a microscope (poorly differentiated)
  • have a BRCA1, BRCA2 or ATM gene change (mutation)
  • have prostate cancer that has spread to other parts of your body (metastatic prostate cancer) and that got worse after treatment with hormonal treatments such as abiraterone or enzalutamide
  • have had surgery to remove your testicles or have been taking drugs to lower the level of testosterone Open a glossary item in your body (luteinising hormone agonists such as goserelin or leuprorelin) 
  • are eligible to receive treatment with a standard prostate cancer treatment (abiraterone, enzalutamide or docetaxel) 
  • have satisfactory blood test results 
  • are fit enough to carry out normal everyday activities apart from hard physical work (performance status 0 or 1
  • are willing to use contraception during treatment and for 6 months afterwards
  • are aged 18 or over
Who can’t take part
 
You cannot join this trial if any of these apply. You have
  • another type of cancer, apart from non melanoma skin cancer, a carcinoma in situ Open a glossary item, or superficial bladder cancer 
  • had treatment for any type of cancer apart from prostate cancer in the last 6 months
  • had a bone marrow transplant in the last 2 years 
  • had previous treatment with another PARP inhibitor 
  • had chemotherapy for prostate cancer after your prostate cancer spread to other parts of your body (metastatic prostate cancer)  
  • cancer that has spread to your brain or spinal cord and is causing symptoms 
  • cancer that is pressing on your spinal cord (spinal cord compression Open a glossary item)
  • stents in your stomach or other problems that might affect how you absorb the drug
  • HIV or AIDS or Hepatitis B or Hepatitis C 
  • had anti-cancer treatment in the last 14 days before starting study treatment, apart from LHRH analogs such as zoladex
  • started or changed treatment for bone thinning (bisphosphonates or denosumab) in the last 28 days before starting study treatment
  • had a minor operation in the last 5 days or a larger operation in the 21 days before starting study treatment
  • have not recovered from the side effects of other cancer treatment unless they are mild, apart from hair loss 
  • have any other serious medical condition or mental health problem that the study team think could affect you taking part

Trial design

This phase 3 trial is taking place worldwide. The researchers need about 400 men to take part including about 30 men from the UK. 
 
This is a randomised trial. The men taking part are put into 2 treatment groups by a computer. They have treatment with either rucaparib or a standard prostate cancer treatment. 
 
Twice as many men will have rucaparib. For every 2 men who have rucaparib, 1 man will have standard treatment. 
 
If you are having standard prostate cancer treatment your doctor will decide whether you have:
  • enzalutamide
  • abiraterone
  • docetaxel 

study diagram

If you are having standard prostate cancer treatment and your cancer worsens, you may be able to start treatment with rucaparib. If this applies to you, your doctor will discuss it further with you.

Treatment with rucaparib

The trial drug rucaparib is a tablet. You take the tablets twice a day, everyday. You have treatment for as long as it is working and the side effects aren’t too bad. 

In some cases, you might continue treatment if your cancer gets worse and your doctor thinks this is in your best interest. But the study team can tell you more if this applies.

Standard treatment 

Docetaxel is a chemotherapy drug. You have it through a drip into your vein (intravenously).

You have docetaxel in cycles of treatment. Each cycle is 3 weeks, and so you have treatment with docetaxel once every 3 weeks. You might have up to 10 cycles of treatment.

Enzalutamide is a capsule and abiraterone is a tablet. You have treatment with one or the other for as long as it is working and the side effects aren’t too bad. 

In some cases, you might continue treatment if your cancer gets worse and your doctor thinks this is in your best interest. But the study team can tell you more if this applies.

Hospital visits

Before starting treatment you will see the doctor and you will have some tests. These tests might include:

  • physical examination
  • medical history
  • blood tests
  • urine sample testing (urinalysis)
  • heart trace (ECG Open a glossary item)
  • CT scan or MRI scan, and bone scan Open a glossary item

Treatment with rucaparib, enzalutamide and abiraterone

You see the doctor about every 2 weeks for the first 2 months, and then once a month after that. At each visit you will have tests and procedures performed, including the following:

  • a physical examination
  • blood tests
  • urine sample tests (urinalysis)

You will have scans every 2 to 3 months after you start study treatment.

Treatment with docetaxel

You see the doctor about every 3 to 4 weeks for up to approximately 10 cycles. At each visit you will have tests and procedures performed, including the following:

  • a physical examination
  • blood tests
  • urine sample tests (urinalysis)

You will have scans every 2 to 3 months after you start study treatment.

Side effects

As rucaparib is just starting to be tested in patients with prostate cancer, there may be side effects we do not know about yet.
 
The possible side effects include:
  • feeling or being sick
  • tiredness (fatigue)
  • taste changes
  • loss of appetite
  • changes in blood test results that measure how your liver and kidneys are working
  • a drop in blood cells causing an increased risk of infection, bleeding problems, tiredness and breathlessness
  • constipation or diarrhoea
  • increased fat (cholesterol) levels in the blood 
  • dizziness
  • difficulty breathing
  • stomach pain
  • sensitivity to sunlight causing itchy or inflamed skin – the study team advise you to avoid long periods in the sun, wear protective clothing and use sunscreen
Read more information about:

Location

Cardiff
Liverpool
London
Oxford
Preston
Slough
Taunton
Wirral

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 Simon Chowdhury

Supported by

Clovis Oncology, Inc 

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

14734

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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