A trial comparing trastuzumab emtansine and taxane chemotherapy for advanced cancer of the stomach (GATSBY)

Cancer type:

Stomach cancer

Status:

Results

Phase:

Phase 2/3

This trial compared trastuzumab emtansine with taxane chemotherapy for cancer of the stomach or cancer where the stomach meets the oesophagus. It was for people whose cancer cells have large amounts of a protein called HER2 (HER2 positive cancer) and had spread.

More about this trial

Doctors can treat HER2 positive cancer Open a glossary item

with drugs such as trastuzumab (Herceptin) which target the HER2 protein. Some stomach cancers (gastric cancer) or cancers where the stomach meets the oesophagus (gastro oesophageal junction cancer) are HER2 positive.

In this trial, researchers looked at a drug called trastuzumab emtansine (Kadcyla). This is a combination of trastuzumab and a chemotherapy drug called emtansine.

They looked at different ways of giving trastuzumab emtansine, and compared it with taxane chemotherapy. Taxane chemotherapy drugs include docetaxel (Taxotere) and paclitaxel (Taxol).

The aims of the trial were to:

find out if trastuzumab emtansine works better than taxane chemotherapy for HER2 positive stomach cancer that has spread
learn more about the side effects

Summary of results

This trial showed that trastuzumab emtansine was no better than taxane chemotherapy for HER2 positive stomach cancer that had spread.

Phase 2

In the phase 2 part of the trial, the researchers were looking for the best way to give trastuzumab emtansine. They recruited 182 people into 1 of 3 treatment groups at random, and:

70 people were in the group which had trastuzumab emtansine every 3 weeks
75 people were in the group which had trastuzumab emtansine every week
37 people were in the group which had taxane chemotherapy (either docetaxel or paclitaxel)

Results from this part of the trial showed that it was better to have trastuzumab emtansine every week, rather than every 3 weeks.

Phase 3

The phase 3 part of the trial recruited another 233 people into 1 of 2 treatment groups at random, and:

153 people were in the weekly trastuzumab emtansine group
80 people were in the taxane chemotherapy group

Results

The research team analysed the results for people recruited during phase 2 and phase 3 of the trial together.

They looked at how long it was before the cancer started to grow. They found it was:

2.7 months for those who had weekly trastuzumab emtansine
2.9 months for those who had taxane chemotherapy

They also looked at how long people lived for and found it was:

7.9 months for those who had weekly trastuzumab emtansine
8.6 months for those who had taxane chemotherapy

Side effects

More than 9 out of 10 people who took part had at least 1 side effect. Some of the side effects were mild or short lived. But 6 out of 10 people who had trastuzumab emtansine and 7 out of 10 people who had taxane chemotherapy had more severe side effects.

The most common side effects of trastuzumab emtansine were a drop in red blood cells and blood clotting cells (platelets). The most common side effects of taxane chemotherapy was a drop in white blood cells and red blood cells.

There is more information about trastuzumab emtansine, paclitaxel and docetaxel in our Cancer Drugs section.

Conclusion

The trial team concluded that trastuzumab emtansine was no better than taxane chemotherapy for HER2 positive stomach cancer that had spread. They wonder if trastuzumab emtansine may work better if people have it in combination with another treatment.

When a trial shows a treatment isn’t useful for a particular group of patients it is still useful. It adds to our knowledge and understanding of cancer and how to treat it.

We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item

) and published in a medical journal. The figures we quote above were provided by the trial team who did the research. We have not analysed the data ourselves.