
Last year in the UK over 60,000 cancer patients enrolled on clinical trials aimed at improving cancer treatments and making them available to all.
Please note - this trial is no longer recruiting patients. We hope to add results when they are available.
This trial is for people with breast cancer that has either:
It is for people whose breast cancer cells are sensitive to the hormone oestrogen (oestrogen receptor positive or ER positive). And whose breast cancer does not have receptors for a protein called HER2 (HER2 negative).
Hormone therapy is a common treatment for locally advanced or secondary breast cancer.
Many breast cancers need the hormone oestrogen to grow. These are called oestrogen receptor positive breast cancers. Doctors think that giredestrant (GDC-9545) might stop oestrogen getting to the cancer cells. It stops growth by blocking oestrogen receptors.
The trial team want to find out if giredestrant works better than hormone therapy drugs we already have. To do this, everyone in this trial will either have giredestrant or another hormone therapy drug.
Your doctor will choose the most suitable hormone treatment for you if you are not having giredestrant. This will either be fulvestrant or an .
The aims of this trial are to find out:
The following bullet points are a summary of 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:
Who can’t take part
Cancer related
You cannot join this trial if any of these apply. You:
Medical conditions
You cannot join this trial if any of these apply. You:
Other
You cannot join this trial if any of these apply. You:
This is a phase 2 trial. The researchers hope 300 people will take part worldwide, including 20 from the UK.
The trial is split into 3 stages:
It is a randomised trial. You are put into one of the following treatment groups by computer:
Both you and your doctor know which group you are in.
Group 1 (giredestrant)
You have giredestrant as a tablet once a day for 28 days. This is one cycle of treatment.
Group 2 (other hormone therapy)
How you have your hormone therapy depends on the drug. You might have it as a tablet or as an injection. Your doctor will explain how and how often, you have the drug.
Everyone who is pre menopausal, or male, will also have a LH blocker. This is to try and block sex hormone production in your body. You usually have this once every treatment cycle.
You will have treatment for as long as it is working, and you can cope with any side effects. This could be for more than 20 months.
Quality of life
The trial team will ask you to fill out questionnaire:
The questionnaires will ask about side effects and how you’ve been feeling. This is called a quality of life study.
Samples for research
The trial team will ask you to give some extra blood samples. Where possible you have these at the same time as your routine samples.
They will ask to look at a sample of tissue you gave when you were first diagnosed.
The researchers plan to look at:
They might also ask you to give a new sample if your cancer gets worse. You don’t have to agree to this. You can still take part in the trial and will not affect your care.
You see a doctor and have some tests before you can take part. These include:
Hospital visits during treatment
You go to the hospital to see the trial team about once a month. Each treatment visit takes around 1 to 6 hours. At each visit, you see the trial doctor for a check up and blood tests.
Depending on the treatment you have, you might record the study treatment you take in a diary at home.
Scans during treatment
You have a CT or MRI scan about:
You have a bone scan around every 24 weeks.
After you have finished treatment you see your trial doctor:
After that, the trial team will catch up with you at least every 6 months for as long as you are willing to see them.
The trial team monitor you during treatment and afterwards. Contact your advice line or tell your doctor or nurse if any side effects are bad or not getting better.
Giredestrant is a new drug. There may be side effects we don’t know about yet. Possible side effects of giredestrant include:
Side effects of hormone therapy for breast cancer include:
A side effect of aromatase inhibitors is bone thinning (osteoporosis) or weakening.
We have more information about hormone therapy for breast cancer. We have more detailed information on fulvestrant, or choose your hormone therapy drug from our A-Z list.
Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.
Dr Sarah Khan
Roche
If you have questions about the trial please contact our cancer information nurses
Freephone 0808 800 4040
Last year in the UK over 60,000 cancer patients enrolled on clinical trials aimed at improving cancer treatments and making them available to all.