A trial of capivasertib for advanced breast cancer that has become resistant to hormone therapy (FAKTION)

Cancer type:

Breast cancer




Phase 2

This trial looked at capivasertib (AZD5363) with a hormone therapy drug called fulvestrant. 

The trial was for women with breast cancer:

  • who were diagnosed after the menopause and
  • their cancer had spread into tissue surrounding the breast or to another part of the body

Cancer Research UK supported this trial.

This trial was open for women to join between 2015 and 2018. The results were published in 2020.

More about this trial

Most breast cancers in women who have been through the menopause Open a glossary item need the hormone oestrogen to grow. Doctors call this oestrogen receptor positive Open a glossary item breast cancer. Doctors can use drugs that either reduce the amount of oestrogen the body makes or stop oestrogen getting to the cancer.

Fulvestrant is a type of hormone therapy that works by blocking oestrogen. But sometimes hormone therapies can stop working and the cancer can start to grow again. This means the cancer has become resistant to these treatments. 

Researchers are looking for new treatments to help those whose breast cancer has become resistant to hormone therapy. In this trial they looked at a drug called capivasertib.

Capivasertib blocks a protein called AKT which stops the cancer growing. Researchers thought that having capivasertib with fulvestrant would help to control the cancer for longer.

The aims of the trial were to find out:

  • if capivasertib and fulvestrant together works better than fulvestrant alone
  • more about the side effects

Summary of results

The trial team found that capivasertib with fulvestrant increased the length of time before the cancer started to grow again.   

About this trial
This was a phase 2 trial. It was a randomised trial. Everyone was put into 1 of 2 groups. 140 women joined this trial and:

  • 69 women had fulvestrant and capivasertib  
  • 71 women had fulvestrant and a dummy drug (placebo Open a glossary item)

Neither the women nor their doctor chose which group they were in. And neither of them knew which group they were in. This is called a double blind trial.

Everyone had treatment for as long as it was working and the side effects weren’t too bad. 

The researchers looked at how long the women were alive with no signs of their cancer getting worse or starting to grow again. They found it was:

  • just over 10 months (10.3) for women who had capivasertib and fulvestrant
  • just under 5 months (4.8) for women who had the dummy drug and fulvestrant 

Side effects
The more serious side effects of having capivasertib with fulvestrant were: 

  • diarrhoea
  • skin rash
  • high blood sugar

The team concluded that the combination of capivasertib and fulvestrant worked for post menopausal women with oestrogen receptor positive breast cancer. It increased the length of time before the cancer started to grow again. And the side effects were manageable. 

The trial team say this provides the basis to do a larger phase 3 trial to confirm these results. 

Where this information comes from    
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.

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 Sacha Howell
Dr Robert Jones

Supported by

Cancer Research UK
Cardiff University, Centre for Trials Research
Experimental Cancer Medicine Centre (ECMC) 
NIHR Clinical Research Network: Cancer
Velindre NHS Trust

Other information

This is Cancer Research UK trial number CRUK/12/044.

Freephone 0808 800 4040

Last review date

CRUK internal database number:


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

Picture of Harriet

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

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