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

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 2

This trial was looking at a drug called AZD8931 for breast cancer. It was for post menopausal Open a glossary item women 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 )

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.