A Phase 3, multicenter, randomized, open-label, active-controlled study of trastuzumab deruxtecan (DS-8201a), an anti-HER2-antibody drug conjugate, versus ado-trastuzumab emtansine (T-DM1) for HER2-positive, unresectable and/or metastatic breast cancer subjects previously treated with trastuzumab and taxane (DESTINY-Breast03)
This study looks at treatment options for adults with HER2-positive breast cancer that has spread to other parts of the body or cannot be removed with surgery. People taking part have already had standard treatments, including trastuzumab and chemotherapy. The trial compares a newer targeted drug called trastuzumab deruxtecan with an established treatment called Kadcyla (trastuzumab emtansine). Both medicines are designed like guided missiles: they attach directly to cancer cells and deliver cancer-killing medicine inside them, which helps spare healthy cells. The main aim is to find out which medicine keeps cancer stable for longer without it growing. Researchers also want to see how long people live overall and check which side effects occur. Everyone in the study receives an active cancer treatment, and no one receives a dummy drug (placebo).
At a glance
What is this study about?
Breast cancer cells sometimes have high levels of a protein called HER2 on their surface. This is known as HER2-positive breast cancer. The HER2 protein causes the cancer cells to grow and divide quickly. Fortunately, modern cancer medicines can target this protein directly to slow down or stop the disease.
In this study, researchers are comparing two targeted treatments called antibody-drug conjugates. These medicines combine an antibody that seeks out HER2 proteins with chemotherapy. Once the medicine finds a cancer cell, it attaches to it and releases its chemotherapy payload inside. The study tests a newer drug, trastuzumab deruxtecan, against a current standard treatment called Kadcyla.
This trial matters because advanced or secondary breast cancer cannot usually be cured, but it can be managed. Finding treatments that keep the cancer under control for longer, while helping people live longer and maintain their quality of life, is an important step forward in cancer care.
Key takeaways
- A Phase 3 clinical trial comparing two targeted treatments for HER2-positive advanced breast cancer.
- Every participant receives an active cancer medicine; no one receives a placebo.
- The study tests whether a newer medicine keeps cancer stable for longer than standard Kadcyla.
- Medicines are given through a drip at the hospital roughly every three weeks.
- Participation is completely voluntary and you can leave the study at any time.
Who may be eligible?
This trial is open to adults aged 18 and over who have HER2-positive breast cancer. It is designed for people whose cancer has spread to other areas of the body (secondary or metastatic cancer) or cannot be safely removed with surgery.
To be suitable, you must have already received certain standard cancer treatments. These include a HER2-targeted medicine called trastuzumab and a type of chemotherapy called a taxane.
You will also need to be reasonably active and well enough to attend regular clinic appointments, have scans, and undergo routine blood tests. Your cancer specialist will check whether your previous medical history and current health make this study safe for you.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- Are you aged 18 or older?
- Do you have confirmed HER2-positive breast cancer?
- Has your cancer spread to other parts of the body or cannot be operated on?
- Have you previously had treatment with trastuzumab and a taxane chemotherapy?
- Are you able to travel to a trial hospital for regular infusions and scans?
What does participation involve?
Taking part involves having treatment at a hospital clinic. You will be placed into one of two groups by chance (like flipping a coin). One group receives trastuzumab deruxtecan and the other receives Kadcyla. Both medicines are given as a drip directly into a vein (intravenous infusion), usually once every three weeks.
You will visit the hospital regularly for your infusions, blood tests, and health checks. Every few weeks, you will have imaging scans, such as CT or MRI scans, to see how the cancer is responding. Treatment continues for as long as it helps keep your cancer under control and you do not have severe side effects. After treatment finishes, the study team will continue to check on your health over the long term.
Potential risks and benefits
Locations (4)
- —UnverifiedBelgium
- —UnverifiedFrance
- —UnverifiedItaly
- —UnverifiedSpain
Common questions
Will I receive a dummy drug (placebo)?
No. Everyone in this study receives an active cancer treatment—either trastuzumab deruxtecan or Kadcyla.
Can I choose which treatment I receive?
No. A computer assigns you to one of the two medicines at random. This makes sure the study results are fair and unbiased.
How often will I need to go to the hospital?
Most participants attend the clinic once every three weeks for their infusion, alongside extra visits for scans and checks.
Do I have to pay for the trial treatment in the UK?
No. The trial medicine and trial-related tests are provided free of charge.
What happens if the treatment stops working?
If your scans show the cancer is growing or if side effects become too difficult, the study treatment will stop and your doctor will discuss other treatment options with you.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
Discussion
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