A trial of datopotamab deruxtecan for breast cancer (TROPION-Breast01)

This trial showed that datopotamab deruxtecan could be a useful treatment for breast cancer that has spread or couldn’t be removed with surgery.

Results
A total of 732 people joined this trial. They were put into 1 of 2 groups at random. There were:

• 365 people in the datopotamab deruxtecan group
• 367 people in the standard chemotherapy group (the control group)

The team analysed the results in 2023 to see how well the treatment had worked.

They looked at how long it was until the cancer had continued to grow in half the people taking part. This is called the median time. They found it was:

• 7 months for those who had datopotamab deruxtecan
• 5 months for those who had standard chemotherapy

They also looked at how many people’s cancer had not continued to grow, 12 months after they joined the trial. They found it was:

• 26 out of 100 people (26%) who had datopotamab deruxtecan
• 15 out of 100 people (15%) who had standard chemotherapy

The team plan to publish more results in the future about whether datopotamab deruxtecan can help people live longer. We hope to update this page once those results are available. 

Side effects
Most people had at least one side effect from treatment. It was:

• more than 9 out of 10 people (94%) who had datopotamab deruxtecan
• less than 9 out of 10 people (86%) who had standard chemotherapy

Many of these were mild or didn’t last long. But some people in each group had more severe side effects. It was:

• just over 2 out of 10 people (21%) who had datopotamab deruxtecan
• more than 4 out of 10 people (45%) who had standard treatment

The most common side effects were:

• feeling sick and a sore mouth (stomatitis) for those who had datopotamab deruxtecan
• a drop in white blood cells causing an increased risk of infection for those who had standard chemotherapy

There is more information about side effects of the standard chemotherapy drugs in our Cancer drugs section:

• capecitabine
• gemcitabine
• eribulin
• vinorelbine

Conclusion
The trial team concluded that datopotamab deruxtecan can help stop breast cancer growing. This was for people with hormone receptor positive and HER2 negative cancer that couldn’t be removed with surgery or had spread. 

They also concluded that it didn’t cause too many side effects.

The team have gone on to do other trials looking at datopotamab deruxtecan for breast cancer. You can find more information about the ‘TROPION-breast’ trials on our clinical trials database.

More detailed information
There is more information about this research in the reference below. 

Please note, the information we link to here is not in plain English. It has been written for healthcare professionals and researchers.

Datopotamab Deruxtecan Versus Chemotherapy in Previously Treated Inoperable/Metastatic Hormone Receptor–Positive Human Epidermal Growth Factor Receptor 2–Negative Breast Cancer: Primary Results From TROPION-Breast01
Aditya Bardia and others
Journal of Clinical Oncology, 2024. Volume 43, issue number 3, pages 285 – 296.

Where this information comes from    
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.