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Study Comparing Trastuzumab Deruxtecan and Trastuzumab Emtansine for Patients with Advanced HER2-Positive Breast Cancer

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a type of breast cancer known as HER2-positive metastatic breast cancer. This is a form of cancer that has spread beyond the breast and is characterized by an overexpression of the HER2 protein. The study is comparing two treatments: trastuzumab deruxtecan, also known by its code name DS-8201a, and ado-trastuzumab emtansine, commonly referred to as T-DM1. Both treatments are designed to target and attack cancer cells that have high levels of the HER2 protein.

The purpose of the study is to determine which of these two treatments is more effective in delaying the progression of the disease. Participants in the study will receive one of the two treatments through an intravenous infusion, which means the medication is delivered directly into the bloodstream through a vein. The study will follow participants over a period of time to monitor the effects of the treatments on their cancer.

Participants in this study have previously been treated with a medication called trastuzumab and a type of chemotherapy known as taxane. The study aims to provide valuable information on the effectiveness of these new treatment options for patients with advanced breast cancer. The results could help improve future treatment strategies for this type of cancer.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on specific criteria, including age, medical history, and previous treatments.

    The study involves patients with HER2-positive breast cancer that is either not removable by surgery or has spread to other parts of the body.

  2. Step 2

    Treatment assignment

    Participants are randomly assigned to receive either trastuzumab deruxtecan (DS-8201a) or ado-trastuzumab emtansine (T-DM1).

    Both medications are administered as a solution through an intravenous infusion.

  3. Step 3

    Medication administration

    The medication is given through a vein in the arm, known as an intravenous infusion.

    The frequency and dosage of the medication are determined by the study protocol and the healthcare team.

  4. Step 4

    Monitoring and assessments

    Regular monitoring is conducted to assess the response to the treatment and any side effects.

    This includes physical exams, blood tests, and imaging studies to track the progress of the cancer.

  5. Step 5

    Completion of treatment

    The treatment continues until the study's end date or until it is determined that the treatment is no longer beneficial.

    Participants are required to follow specific guidelines regarding contraception during and after the study to prevent pregnancy.

  6. Step 6

    Follow-up

    After completing the treatment, follow-up visits are scheduled to monitor long-term health and any delayed side effects.

    The study aims to compare the time during which the cancer does not worsen between the two treatments.

Who can join the trial?

9 criteria

  • Must be an adult aged 18 years or older. If the legal age of consent is higher than 18, that age applies.
  • Must have breast cancer that is either unresectable (cannot be removed by surgery) or metastatic (has spread to other parts of the body).
  • The cancer must have a confirmed HER2 positive expression, which means the cancer cells have more HER2 proteins than normal, as determined by specific guidelines.
  • Must have been previously treated with the drugs trastuzumab and taxane in advanced or metastatic settings, or the cancer progressed within 6 months after treatment that included these drugs.
  • Must show documented radiologic progression, meaning the cancer has grown or spread as seen in medical imaging, during or after the most recent treatment, or within 6 months after completing therapy.
  • Must be confirmed as HER2 positive by a central laboratory using the most recent tumor tissue sample available.
  • Female participants who can have children must agree to use a highly effective form of birth control or avoid intercourse during the study and for at least 7 months after the last dose of the study drugs. Male participants must inform potential female partners about the trial and agree to use birth control or avoid intercourse during the study and for at least 4.5 months after the last dose of the study drugs.
  • Must have adequate renal function, meaning the kidneys are working well enough, with a creatinine clearance of at least 30 mL/min.
  • Must have adequate hepatic function, meaning the liver is working well enough, with total bilirubin levels within specific limits and liver enzymes (AST/ALT) not exceeding 5 times the upper limit of normal.

Who cannot join the trial?

6 criteria

  • Patients who have not been previously treated with trastuzumab and taxane. These are specific types of cancer treatments.
  • Patients with breast cancer that is not HER2-positive. This means the cancer does not have high levels of a protein called HER2.
  • Patients whose breast cancer is not unresectable or metastatic. "Unresectable" means the cancer cannot be removed with surgery, and "metastatic" means the cancer has spread to other parts of the body.
  • Patients who are not within the specified age range for the study.
  • Patients who are not part of the specified clinical trial groups.
  • Patients who are not considered part of the vulnerable population selected for the study.
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Investigated drugs

  • Trastuzumab Deruxtecan (DS-8201a)

    is a medication used in this clinical trial. It is an anti-HER2-antibody drug conjugate, which means it is designed to target and attach to HER2 proteins on cancer cells. Once attached, it delivers a chemotherapy drug directly to the cancer cells, helping to destroy them. This medication is being tested for its effectiveness in treating HER2-positive, unresectable, and/or metastatic breast cancer in patients who have already been treated with trastuzumab and a taxane.

  • Ado-Trastuzumab Emtansine (T-DM1)

    is another medication involved in the trial. It is also an anti-HER2-antibody drug conjugate, similar to trastuzumab deruxtecan. It works by binding to the HER2 proteins on cancer cells and delivering a chemotherapy drug to these cells. This medication is used as a comparison to evaluate the effectiveness of trastuzumab deruxtecan in the study. It is intended for patients with HER2-positive, unresectable, and/or metastatic breast cancer who have previously received treatment with trastuzumab and a taxane.

What is already known about the treatment

  • Trastuzumab Deruxtecan

    This medication is administered intravenously and is currently being studied in clinical trials for its effectiveness in treating HER2-positive, unresectable, and metastatic breast cancer. It is an antibody-drug conjugate that targets the HER2 protein on cancer cells, delivering a cytotoxic agent directly to the tumor, which helps to kill the cancer cells. Trastuzumab Deruxtecan is classified as an anti-HER2 therapy and is being compared to other treatments to assess its benefits in prolonging progression-free survival in patients.

  • Ado-Trastuzumab Emtansine (T-DM1)

    This medication is also given intravenously and is used in the treatment of HER2-positive metastatic breast cancer. It combines the HER2-targeting properties of trastuzumab with a chemotherapy agent, emtansine, to deliver targeted treatment to cancer cells. T-DM1 works by binding to the HER2 protein and releasing the chemotherapy agent inside the cancer cells, leading to cell death. It is classified as an antibody-drug conjugate and is a standard treatment option for patients who have previously received trastuzumab and taxane therapies.

Investigated diseases

Metastatic breast cancer – This is a type of breast cancer that has spread beyond the breast to other parts of the body, such as the bones, liver, lungs, or brain. It is considered an advanced stage of breast cancer, often referred to as stage IV. The disease progresses as cancer cells travel through the bloodstream or lymphatic system to form new tumors in other organs. Symptoms can vary depending on where the cancer has spread, but may include bone pain, difficulty breathing, or neurological symptoms. The progression of metastatic breast cancer can be influenced by factors such as the cancer's hormone receptor status and HER2 status. It is a chronic condition that requires ongoing management to control the spread and alleviate symptoms.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-511204-16-00Protocol codeDS8201-A-U302Estimated enrolment240 patientsSponsorDaiichi Sankyo Inc.

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