Badanie oceniające skuteczność, bezpieczeństwo i farmakokinetykę GDC-9545 w skojarzeniu z palbocyklibem w porównaniu z anastrozolem w skojarzeniu z palbocyklibem u kobiet po menopauzie z nieleczonym wcześniej rakiem piersi z obecnością receptorów estrogenowych i bez obecności receptorów HER2

How does the coopERA clinical trial work?

This clinical trial is recruiting post-menopausal women (no longer menstruating) who have been diagnosed with early oestrogen receptor (ER)-positive/human epidermal growth factor 2 (HER2)-negative breast cancer. 

ER-positive means that the cells of this type of breast cancer have receptors (special structures on the outside of the cell) that allow them to use the hormone oestrogen to grow. HER2-negative means that your cancer has low levels of a protein called HER2.

The purpose of this study is to compare the effects, good or bad, of giredestrant versus anastrozole alone (single-agent treatment) followed by giredestrant plus palbociclib versus anastrozole plus palbociclib (combination treatment) in patients with your type of early breast cancer. In this study, you will get either giredestrant or anastrozole alone (single-agent treatment) followed by the same drug in combination with palbociclib.

How do I take part in this clinical trial?

To be able to take part in this clinical trial, you must have been diagnosed with early breast cancer, be at least 18 years old at the time of giving informed consent, be post-menopausal and be willing to have surgery to remove your breast cancer tissue after clinical trial treatment. 

You must not have previously received any medicine for your breast cancer. If you have previously received certain other medications or have certain other medical conditions, you may not be able to take part in this clinical trial.

If you think this clinical trial may be suitable for you and would like to take part, please talk to your doctor. If your doctor thinks that you might be able to take part in this clinical trial, he/she may refer you to the closest clinical trial doctor. They will give you all the information you need to make your decision about taking part in the clinical trial. You can also find the clinical trial locations on this page.

You will have some further tests to make sure you will be able to take the treatments given in this clinical trial. Some of these tests or procedures may be part of your regular medical care. They may be done even if you do not take part in the clinical trial. If you have had some of the tests recently, they may not need to be done again. All patients will be required to provide three tumour tissue samples: one before treatment begins, one during treatment, and one after treatment. 

Before starting the clinical trial, you will be told about any risks and benefits of taking part in the trial. You will also be told what other treatments are available so that you may decide if you still want to take part. 

What treatment will I be given if I join this clinical trial?

Everyone who joins this clinical trial will be split into two groups randomly (like flipping a coin) and given either:

• Giredestrant alone (single-agent treatment), as a pill, once a day for two weeks
  • Following this you will receive giredestrant once a day for 28 days AND palbociclib as a pill once a day for 21 days of every 28-day treatment cycle 
• OR anastrozole alone (single-agent treatment), as a pill, once a day for two weeks
  • Following this you will receive anastrozole once a day for 28 days AND palbociclib as a pill once a day for 21 days of every 28-day treatment cycle 

One cycle of combination treatment will last for 28 days and you will have four cycles (four months) of treatment. You will then undergo surgery to remove your breast cancer tissue.

You will have a 1 in 2 (50%) chance of being placed in either group. 

This is an open-label trial which means that you and your clinical trial doctor will know which treatment you are receiving.

How often will I be seen in follow-up appointments and for how long?

You will receive clinical trial treatment for approximately 18 weeks and then undergo surgery to remove your breast cancer tissue.

You are free to stop this treatment at any time. During this study, you will have approximately 10–11 visits while you are receiving treatment. Most visits will last approximately one hour. Some visits may last up to three hours. After you have completed your clinical trial treatment and have undergone surgery to remove your breast cancer, you will have one final visit with your clinical trial doctor. 

The visits will include checks to see how you are responding to the treatment and any side effects that you may be having.

What happens if I am unable to take part in this clinical trial?

If this clinical trial is not suitable for you, you will not be able to take part. Your doctor will suggest other clinical trials that you may be able to take part in or other treatments that you can be given. You will not lose access to any of your regular care.

For more information about this clinical trial see the For Expert tab on the specific ForPatient page or follow this link to ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT04436744

Trial-identifier: NCT04436744