A trial comparing a combination of capecitabine and lapatinib (GW 572016) with capecitabine alone for advanced breast cancer (EGF 100151)

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 3

This trial was looking at capecitabine (Xeloda), with or without lapatinib, for advanced breast cancer.

Doctors usually treat breast cancer with surgery, and one or more of chemotherapy, radiotherapy, hormone therapy or biological therapy. But sometimes these treatments don’t work and the cancer comes back (recurs) or spreads (metastasises) to another part of the body. This is known as advanced, metastatic or secondary breast cancer.

Capecitabine is a chemotherapy drug that was already in use for advanced breast cancer. Lapatinib (GW 572016) was a new drug that was being looked at as a possible treatment for various types of cancer.

There are a number of growth factor receptors on breast cancer cells. When these receptors are triggered, they tell the cell to grow and divide into 2 new cells. Lapatinib targets 2 of these receptors. The first is called erbB1, or epidermal growth factor receptor (EGFR). The second is called erbB2, or HER2/neu receptor. Doctors hoped that by targeting 2 different receptors at the same time, the drug would be better at treating breast cancer. But they didn’t know for sure how well it would work.

The aim of this trial was to compare capecitabine alone to capecitabine and lapatinib to see which was better for advanced breast cancer.

Summary of results

The researchers found that advanced breast cancer responded to capecitabine and lapatinib more often than it responded to capecitabine alone. And in women who had both drugs, it took longer for the cancer to start growing again.

This was a randomised trial.

399 women had treatment in this trial
Half had lapatinib and capecitabine
Half had capecitabine alone

The researchers looked at how many women responded to the treatment. For the group having both drugs,

In 1 women the cancer disappeared completely – researchers call this a complete response
In 46 women, the cancer had got smaller – researchers call this a partial response

In the group of women who had capecitabine alone, there were no complete responses, and 28 partial responses.

Most of the women in both groups had some side effects. Side effects such as diarrhoea, sickness and a rash happened more often in the group of women who had both drugs.

The researchers found that the average time it took for the cancer to start growing again was

Just over 27 weeks in the group of women who had both drugs
Just over 18 and a half weeks in the group of women who had capecitabine alone

We have based this summary on information from the team who ran the trial. 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 trial team. We have not analysed the data ourselves.