A trial looking at trastuzumab emtansine for HER2 positive breast cancer (TH3RESA)
Cancer type:
Status:
Phase:
This trial was for people whose breast cancer has spread to the surrounding tissue (locally advanced) or to another part of the body (secondary breast cancer). They had already had treatment with both trastuzumab (Herceptin) and lapatinib.
More about this trial
Some breast cancers have large amounts of a protein called 
on the surface of the cells. These cancers are HER2 positive. They can be treated with drugs that target the HER2 protein including:
- trastuzumab (Herceptin)
- pertuzumab
- lapatinib
People can also be treated different types of chemotherapy, including a drug called a .
Trastuzumab emtansine is a combination of trastuzumab and the chemotherapy drug, DM1. Trastuzumab finds the cancer cells and delivers the DM1 to them. This type of drug is called a conjugated monoclonal antibody.
The aim of this trial was to find out how well trastuzumab emtansine works for people with HER2 positive breast cancer
- whose cancer has spread into the surrounding tissue (locally advanced) or elsewhere in the body (secondary or advanced breast cancer)
and
- they have already been treated with both trastuzumab and lapatinib and their cancer has got worse
Summary of results
The people who took part in this trial had HER2 positive advanced breast cancer previously treated with trastuzumab, lapatinib and a taxane chemotherapy. The researchers found that trastuzumab emtansine worked well for this group of people.
602 people took part in the trial.
- 404 had trastuzumab emtansine
- 198 had treatment recommended by their doctor
The researchers looked at the length of time it took before people’s cancer got worse. This is called progression free survival. This was:
- just over 6 months (6.2) in the group having trastuzumab emtansine
- just over 3 months (3.3) in the group having treatment recommended by their doctor
The researchers also looked at the length of time people lived after treatment. This is called overall survival. This was:
- just under 23 months (22.7) in the group having trastuzumab emtansine
- just under 16 months (15.8) in the group having treatment recommended by their doctor
They looked at the side effects people had in both groups and how severe these side effects were. People having trastuzumab emtansine had less severe side effects.
The most common side effects of trastuzumab emtansine were:
- tiredness (fatigue)
- weakness and lacking energy
- a reduction in the number of platelets in the blood (thrombocytopenia), these help the blood to clot
The most common side effects from the treatment chosen by doctors included:
- tiredness (fatigue)
- a reduction in the number of white blood cells in the blood (neutropenia), these help to fight infection
- diarrhoea
The researchers concluded that trastuzumab emtansine should be used as a for people with advanced HER 2 positive breast cancers who have had previous treatment.
Recruitment start:
Recruitment end:
How to join a clinical trial
Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.
Chief Investigator
Dr Stephen Houston
Supported by
Experimental Cancer Medicine Centre (ECMC)
F. Hoffmann-LaRoche
NIHR Clinical Research Network: Cancer
If you have questions about the trial please contact our cancer information nurses
Freephone 0808 800 4040
Last review date
CRUK internal database number:
Last reviewed:
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