A trial of TDM1 after surgery for breast cancer (KATHERINE)
Cancer type:
Status:
Phase:
This trial looked at trastuzumab emtansine (TDM1) to reduce the risk of breast cancer coming back or spreading elsewhere in the body.
It was for people:
- who’d had treatment to shrink their cancer before surgery but had some cancer remaining
- whose cancer was
HER2 positive 
The trial was open for people to join between 2013 and 2015. The team published some early results in 2019. They presented longer term results at a conference in December 2023.
More about this trial
Doctors sometimes give treatment before surgery for breast cancer. This is called neo adjuvant treatment. It can help make the cancer smaller and easier to remove.
Some breast cancers have large amounts of a protein called HER2. This is called HER2 positive breast cancer. Doctors can treat HER2 positive cancer with drugs such as trastuzumab (Herceptin), which targets the HER2 protein. In this trial, everyone had trastuzumab and chemotherapy before surgery.
The risk of breast cancer coming back or spreading after surgery is higher if there are still some cancer cells in the breast or . Doctors wanted to see if trastuzumab emtansine could help reduce this risk.
Trastuzumab emtansine is also called TDM1 or Kadcyla. It is a combination of:
- the targeted treatment trastuzumab (Herceptin)
- the chemotherapy drug emtansine (DM1)
Some people in the trial had trastuzumab after surgery. This was the . And some had TDM1.
The main aims of this trial were to:
- compare TDM1 with trastuzumab to see which works best
- learn more about the side effects
Summary of results
The trial team found that TDM1 worked better than trastuzumab after surgery for breast cancer that hadn’t spread.
About this trial
This trial took place worldwide. A total of 1,486 people took part. They were put into a treatment group at random. There were:
- 743 people in the TDM1 group
- 743 people in the trastuzumab group
Everyone had up to 14 cycles of treatment. This took about a year. Some people also had radiotherapy or hormone therapy if their doctor thought they needed it. This was standard treatment and not part of the trial.
Results
Researchers looked at how well treatment worked more than 8 years after people joined the trial.
They looked at the number of people whose cancer had come back or spread to another part of the body. They found it was:
- 239 people (32%) who had trastuzumab
- 146 people (20%) who had TDM1
They also looked at the number of people who were living. They found it was:
- 461 people (62%) who had trastuzumab
- 521 people (70%) who had TDM1
Side effects
The most common side effects of TDM1 were:
- extreme tiredness (fatigue)
- feeling sick
- liver changes
- aches and pains in muscles and bones
Some of these side effects were mild or didn’t last long.
Some people had side effects that were more serious. These affected more people who had TDM1 and 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.
Conclusion
The trial team concluded that TDM1 is better at stopping breast cancer coming back or spreading after surgery, compared to trastuzumab. They suggest it should be standard treatment for this group of patients.
More detailed information
There is more information about this research in the links below.
Please note, some of the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.
Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer
G von Minckwitz and others
New England Journal of Medicine, 2019. Issue 380, pages 617 – 628.
Genentech’s Kadcyla Is the First Targeted Therapy to Show Significant Overall Survival Benefit in People With HER2-Positive Early-Stage Breast Cancer With Residual Invasive Disease After Neoadjuvant Treatment
Genentech press release, December 2023.
Accessed June 2024.
Adjuvant T-DM1 Provides Sustained Survival Benefit in HER2+ Early Breast Cancer
OncLive website, December 2023.
Accessed June 2024.
Where this information comes from
We have based this summary on the information in the article above. Some of the information has been reviewed by independent specialists () and published in medical journals. Some of the information may not have been. We have not analysed the data ourselves. As far as we are aware, the links we list above are active and the articles are free and available to view.
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
Professor Andrew Wardley
Supported by
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer
Roche
Genentech
If you have questions about the trial please contact our cancer information nurses
Freephone 0808 800 4040
