A trial of AZD4547 for breast cancer that got worse despite hormone therapy (RADICAL)

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 2

This trial looked at a drug called AZD4547 alongside anastrozole or letrozole for breast cancer that got worse despite hormone therapy. It was for women with oestrogen receptor positive (ER positive) breast cancer.

ER positive Open a glossary item means that the breast cancer cells are sensitive to the female hormone oestrogen.

This trial was supported by Cancer Research UK.

More about this trial

Hormone therapy is a common treatment for women with ER positive breast cancer. Anastrozole and letrozole are hormone therapy drugs that are a common treatment for breast cancer. But sometimes, they stop working. Doctors describe this as becoming resistant Open a glossary item .

You usually have treatment with another hormone therapy drug if this happens. But doctors are looking for new ways to help women in this situation.

In this trial, they looked at a drug called AZD4547 to see if women can benefit from taking anastrozole or letrozole again.

AZD4547 is a type of targeted cancer drug called a cancer growth blocker. It stops signals that cancer cells use to divide and grow.

The main aim of this trial was to find out how well AZD4547 with anastrozole or letrozole works as a treatment so that women can benefit from these hormone therapies again.

Summary of results

The trial team concluded that AZD4547 with anastrozole or letrozole helps women with ER positive breast cancer.

This was a phase 1/2 trial. 58 women with advanced breast cancer took part.

Everyone had treatment with AZD4547 and 1 of following drugs:

anastrozole (Arimidex)
letrozole (Femara)

The dose of AZD4547 women had depended on when they joined the trial. Everyone had treatment for as long as their cancer shrunk, stayed the same or didn’t get worse. When their cancer got worse (disease progression Open a glossary item ), women stopped having treatment.

The trial team looked at how well AZD4547 worked for the women after 12 weeks of treatment and again at 28 weeks.

To do this they looked at the number of women whose cancer stayed the same (stable disease Open a glossary item ), or shrunk by at least a third (partial response ).

After 12 weeks of treatment, they found that out of the 52 women:

1 woman had a partial response
18 women had stable disease

And after 28 weeks of treatment, they found that out of the 52 women:

2 women had a partial response
11 women had stable disease

The team also looked at the average length of time women lived without any signs of their cancer getting worse. Doctors call this progression free survival. They found that on average, women lived around 3 months without any signs of their cancer getting worse.

The research team looked at the side effects women had. The team found that all the side effects were mild. The most common side effects were:

high levels of phosphate in the blood
hair loss (alopecia)
taste changes
indigestion
constipation and diarrhoea
feeling sick

The trial team concluded that AZD4547 with anastrozole or letrozole helps women with advanced breast cancer. They think this is a safe treatment.

The team thinks there should be more research looking for substances (biomarkers Open a glossary item ) that can tell who benefits from this treatment.

We have based this summary on information from the research team. As far as we are aware, the information they sent us has not been reviewed independently (peer reviewed Open a glossary item ) or published in a medical journal yet. The figures we quote above were provided by the research team. We have not analysed the data ourselves.