A trial comparing two hormone therapies for breast cancer (FALCON)

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

Cancer type:

Breast cancer

Status:

Closed

Phase:

Phase 3

This trial is comparing the hormone therapies fulvestrant (Faslodex) and anastrozole (Arimidex) for breast cancer in post menopausal Open a glossary item women. This trial is for women whose breast cancer cannot be removed with surgery or has spread to another part of the body.

Most breast cancers in post menopausal women need the hormone oestrogen Open a glossary item to grow. Doctors can use drugs that either reduce the amount of oestrogen the body makes or stop oestrogen getting to the cancer.

Fulvestrant works by blocking oestrogen. Anastrozole works by reducing the amount of oestrogen the body makes. A small study suggests that fulvestrant may be better at treating breast cancer than anastrozole. The researchers want to do a larger trial to find out if this is so.

The aim of this trial is to compare fulvestrant with anastrozole to find out which is best for post menopausal women with breast cancer.

Who can enter

You may be able to enter this trial if

  • You have breast cancer that spread into the surrounding tissues (is locally advanced) and can’t be cured or your breast cancer has spread to another part of your body
  • Your breast cancer has tested positive for hormone receptors
  • You have at least 1 area of cancer that can be seen on a CT scan, MRI scan or X-ray
  • Your periods have stopped permanently (you are post menopausal Open a glossary item)
  • You have satisfactory blood test results
  • You are well enough to be up and about for at least half the day (performance status 0, 1 or 2)

You cannot enter this trial if

  • You have had treatment for your breast cancer that reaches your whole body (systemic treatment Open a glossary item) – if you have had chemotherapy you may be able to take part if you had only 1 type of chemotherapy
  • You have had radiotherapy in the past month
  • You are able to have trastuzumab (Herceptin)
  • You have taken an experimental drug as part of a clinical trial in the past month
  • You have used hormone replacement therapy Open a glossary item (HRT) that contains oestrogen in the past 6 months
  • You have had another cancer in the past 5 years apart from non melanoma skin cancer, carcinoma in situ of the cervix or any other cancer that has been successfully treated and there has been no sign of it for the past 5 years
  • You have a problem with bleeding
  • You are taking blood thinning medication, such as warfarin
  • You are sensitive to anastrozole, fulvestrant, castor oil or their ingredients
  • You have any other medical condition that could affect you taking part in this trial

Trial design

This is an international phase 3 trial. It will recruit 450 women.

It is a randomised trial. The women taking part are put into 1 of 2 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.

  • Women in group 1 will have fulvestrant and a dummy drug (placebo)
  • Women in group 2 will have anastrozole and a dummy drug

FALCON trial diagram

Fulvestrant is an injection into a muscle. You have 2 injections, one into each buttock. For women in this group, the dummy drug is a tablet. You take the tablet once a day with a glass of water.

Anastrozole is a tablet. You take it once a day with a glass of water. For women in this group, the dummy drug is an injection into a muscle. You have 2 injections, one into each buttock.

You have treatment in 4 week periods. To start with you have the injections every 2 weeks. After 4 weeks of treatment, you have the injections every 4 weeks. You start taking the tablets from the beginning of treatment.

You continue treatment as long as it is helping you and the side effects aren’t too bad.

The trial team will ask you to fill out 2 questionnaires when you start treatment, every 3 months during treatment and after you finish treatment. The questionnaires will ask about side effects and how you’ve been feeling. This is called a quality of life study.

If you agree to take part in this trial, the researchers will ask for a sample of your cancer that was removed when you had a biopsy Open a glossary item. If you don’t want to give this sample for research, you don’t have to. You can still take part in the trial.

Hospital visits

You see the doctor before taking part in the trial to have some tests. These tests include

You see your doctor every 4 weeks to see how you are. You have the blood tests, scans and heart trace every 3 months.

You see the doctor at the end of treatment for the same tests and then every 3 months.

Side effects

The most common side effects of fulvestrant include

The most common side effects of anastrozole include

  • Headaches
  • Hot flushes and sweats
  • Feeling sick
  • Skin rashes
  • Painful or stiff joints
  • Swollen joints (arthritis)
  • Feeling weak
  • Loss of bone density which can increase the risk of bones breaking
  • Mood changes
  • Tiredness
  • A lowered interest in sex

Your doctor will talk to you about the possible side effects before you agree to take part in this trial.

We have information on fulvestrant and anastrozole.

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 John Robertson

Supported by

AstraZeneca
NIHR Clinical Research Network: Cancer

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 9718

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

A picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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