A trial looking at lapatinib and trastuzumab for breast cancer that has not spread (ALTTO)

Cancer type:

Breast cancer

Status:

Results

Phase:

Phase 3

This trial was looking at lapatinib and trastuzumab (Herceptin) to see which was best at stopping breast cancer from coming back after treatment. It was for people with breast cancer that produces too much of a protein called HER2 Open a glossary item . This is known as HER2 positive breast cancer.

More about this trial

Doctors can treat HER2 positive breast cancer with

The HER2 protein makes cancer cells grow and divide. Trastuzumab blocks HER2 and stops the cells growing and dividing into new cells. We know that trastuzumab reduces the risk of HER2 positive breast cancer coming back.

A drug called lapatinib blocks HER2 and another protein called erbB1 or epidermal growth factor receptor (EGFR). Earlier trials had shown that lapatinib helped people with breast cancer that had spread.

In this trial, researchers wanted to find out whether lapatinib would help people whose breast cancer had not spread. The aim of the trial was to see if lapatinib on its own, or in combination with trastuzumab, was better at stopping breast cancer from coming back than trastuzumab alone.

Summary of results

The researchers found that lapatinib and trastuzumab wasn’t better at stopping breast cancer coming back than trastuzumab alone.

The trial recruited over 8,000 people in 44 countries. It was a randomised trial. The people taking part were put into 1 of 4 treatment groups by a computer. Neither they nor their doctor could decide which group they were in.

They had one of the following treatments for a year

• Trastuzumab alone
• Lapatinib alone
• Trastuzumab followed by lapatinib
• Trastuzumab and lapatinib at the same time

But the information being collected from the lapatinib alone group showed that on its own, lapatinib was not likely to work as well as it had been hoped and this group closed in 2011. So these results are from people in the other 3 groups.

The researchers followed up the people taking part for an average of 4½ years. They looked at the average length of time people lived without any signs of their breast cancer coming back. Doctors call this disease free survival. They found that any differences between the groups could have happened by chance. This means they were not statistically significant Open a glossary item .

They also found that people having lapatinib had more side effects such as diarrhoea and skin rash.

The trial team concluded that after 4 ½ years, disease free survival was about the same for people who had trastuzumab and people who had both trastuzumab and lapatinib. But they will continue to monitor the people taking part for another 2 years.

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.