A trial of AZD8931 and anastrozole for hormone receptor positive advanced breast cancer (MINT)

Cancer type:

Breast cancer




Phase 2

This trial was looking at a drug called AZD8931 for breast cancer. It was for post menopausal Open a glossary itemwomen with breast cancer that was locally advanced, or had spread to another part of the body, and was hormone receptor positive.

Doctors often use hormone therapy to treat breast cancer. One of the drugs they commonly use is called anastrozole. Researchers are looking for ways to improve standard treatments Open a glossary item. In this study, they were looking at a drug called AZD8931 together with anastrozole.

AZD8931 is a type of biological therapy. It works by blocking certain proteins in cancer cells that send signals telling the cells to divide. Turning off this signalling can help to kill cancer cells.

The aims of this trial were to see

  • If having AZD8931 and anastrozole together was safe
  • If having both drugs worked better than anastrozole alone for advanced hormone receptor positive breast cancer.

Summary of results

The researchers found that adding AZD8931 did not work better than anastrozole alone.

The trial recruited 359 women. Their average age was 61. They all had breast cancer that was hormone receptor positive and they hadn’t had any other hormone treatment for breast cancer before joining the trial.

The trial was randomised. The women taking part were put into 1 of 3 groups by a computer. Neither they nor their doctors could decide which group they were in.

Everybody took anastrozole tablets

  • 118 women also took a low dose of AZD8931 tablets
  • 120 women also took a higher dose of AZD8931 tablets
  • 121 women took dummy tablets (placebos Open a glossary item)

The researchers looked at some early results to see how long the women were living without any signs that their cancer was getting worse. They found that on average this was

  • Just under 11 months in the women taking the lower dose of AZD8931
  • Just under 14 months in the women taking the higher dose
  • 14 months in the women taking the dummy drugs

Women in all 3 groups had side effects, but serious side effects were more common in the groups having AZD8931 than in the anastrozole alone group. And more women having AZD8931 stopped anastrozole treatment because of bad side effects compared with the anastrozole alone group.

In view of these results, the committee that monitors the safety and design of the trial (the data monitoring committee) recommended that the trial was stopped. This was because these results suggested it was very unlikely the trial would be able to show that AZD8931 and anastrozole was better than anastrozole alone.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) but may not have been published in a medical journal.  The figures we quote above were provided by the trial team. 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

Professor Stephen Johnston

Supported by

Experimental Cancer Medicine Centre (ECMC)
National Institute for Health Research Cancer Research Network (NCRN)

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Last review date

CRUK internal database number:

Oracle 5673

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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