“I had treatment last year and I want to give something back.”
A trial of TDM1 after surgery for breast cancer (KATHERINE)
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This trial looked at a drug called trastuzumab emtansine (TDM1) to reduce the risk of breast cancer coming back or spreading elsewhere in the body.
It was for people:
- who had treatment to shrink their cancer before surgery but had some cancer remaining
- whose cancer was
This trial was open for people to join between 2013 and 2015. The results were published in 2018.
More about this trial
You may have treatment before breast cancer surgery to try to reduce the size of the cancer and make it easier to remove. This is neoadjuvant treatment.
Some breast cancers have large amounts of a protein called HER2. This is HER2 positive breast cancer. Doctors can treat HER2 positive cancer with drugs such as trastuzumab, which targets the HER2 protein. In this trial, everyone had trastuzumab (Herceptin) and chemotherapy before surgery.
Having cancer remaining in the breast or
In this trial, they looked at a drug called trastuzumab emtansine (TDM1). It is a combination of:
- a chemotherapy drug called DM1
Some people in the trial had more trastuzumab. This was the
The aims of this trial were to:
- compare TDM1 with trastuzumab to see which worked best
- learn more about the side effects.
Summary of results
The trial team found that TDM1 worked better than trastuzumab for people with breast cancer that hadn’t spread. It reduced the risk of the cancer coming back or spreading elsewhere in the body. But the side effects of TDM1 were worse.
These are early results. The trial team plan to collect more information to see how long people live.
About this trial
This trial took place worldwide. 1,486 people took part and:
- 743 had TDM1
- 743 had trastuzumab
Everyone had up to 14 cycles of treatment. This took about a year. Some people also had radiotherapy or
Researchers looked at how well treatment worked. They did an early analysis of the results in 2018. This is an interim analysis.
They looked at the number of people whose cancer had come back. This was:
- 91 people who had TDM1
- 165 people who had trastuzumab
They also looked at the number of people whose cancer had spread elsewhere in the body. This was:
- 78 people who had TDM1
- 118 people who had trastuzumab
They found the number of people who had died was:
- 42 people who had TDM1
- 56 people who had trastuzumab
More people in the TDM1 group had serious side effects. These included:
- an increased risk of bleeding
- high blood pressure
133 people stopped TDM1 early due to side effects. The most common reasons were:
- an increased risk of bleeding
- liver changes
- numbness and tingling in the hands and feet
- heart changes
These side effects got better after stopping treatment or reducing the dose.
A serious side effect in the trastuzumab group was high blood pressure.
The trial team found that TDM1 halved the risk of the cancer coming back. But the side effects were worse.
The trial team plan to follow these people up for longer. We hope to add further results when they become available.
Where these results come from
We have based this summary on information from the research team. The information they sent us has been reviewed by independent specialists (
How to join a clinical trial
Dr Andrew Wardley
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer