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Study Comparing Trastuzumab Deruxtecan and Trastuzumab Emtansine for Patients with High-Risk HER2-Positive Breast Cancer with Residual Disease After Initial Treatment

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 breast cancer. This is a form of cancer where the cancer cells have more HER2 protein than normal, which can make the cancer grow more quickly. The study is specifically looking at patients who have a high risk of their cancer returning after they have already received initial treatment, known as neoadjuvant therapy, which is treatment given before surgery to shrink the tumor. The trial will compare two treatments: Trastuzumab Deruxtecan, also known by its code name DS-8201a, and Trastuzumab Emtansine, also referred to as T-DM1. Both of these treatments are given as an infusion, which means they are administered directly into the bloodstream through a vein.

The purpose of the study is to evaluate how well Trastuzumab Deruxtecan works compared to Trastuzumab Emtansine in preventing the cancer from coming back. Participants in the study will be randomly assigned to receive one of these two treatments. The study will monitor the participants over a period of time to see if the cancer returns, spreads, or if there are any other significant health changes. Some participants may receive a placebo, which is a substance with no active medication, to help compare the effects of the actual treatments.

Throughout the study, participants will have regular check-ups and tests to monitor their health and the status of their cancer. These may include physical exams, blood tests, and imaging tests like scans. The study aims to provide valuable information on which treatment might be more effective for patients with high-risk HER2-positive breast cancer who have residual disease after initial therapy. The results could help guide future treatment decisions for this type of breast cancer.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Randomization

    After meeting the eligibility criteria, the patient is randomly assigned to one of two treatment groups. This process is called randomization and ensures that each participant has an equal chance of receiving either treatment.

  2. Step 2

    Treatment administration

    The patient receives treatment with either trastuzumab deruxtecan or trastuzumab emtansine. Both medications are administered as a solution for infusion through a vein, a method known as intravenous use.

    The specific dosage and frequency of administration are determined by the study protocol and the patient's assigned treatment group.

  3. Step 3

    Monitoring and assessments

    Throughout the trial, the patient's health is closely monitored. This includes regular physical examinations, blood tests, and imaging studies to assess the response to treatment and detect any side effects.

    The patient's heart function is evaluated using tests such as echocardiograms or MUGA scans, as maintaining a healthy heart is important during treatment.

  4. Step 4

    Follow-up

    After completing the treatment phase, the patient enters a follow-up period. During this time, the patient's health continues to be monitored to evaluate the long-term effects of the treatment and to check for any signs of cancer recurrence.

    The follow-up period helps gather important information about the effectiveness and safety of the treatments being studied.

Who can join the trial?

16 criteria

  • Sign and date the necessary forms before starting any study-specific procedures.
  • Have a known hormone receptor status, which is determined by a local lab. This means knowing if the cancer is affected by hormones like estrogen or progesterone.
  • Have a left ventricular ejection fraction (LVEF) of at least 50% within 28 days before joining the study. LVEF is a measure of how well the heart pumps blood.
  • Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. This is a scale that measures how well you can perform daily activities.
  • Have adequate organ function within 14 days before joining the study, as defined in the study protocol.
  • Agree to use a highly effective form of birth control or avoid intercourse during the study and for a certain period after the study ends. This applies to both men and women.
  • Men must not freeze or donate sperm during the study and for at least 4 months after the last dose of the study drug. They may consider preserving sperm before joining the study.
  • Women must not donate or retrieve eggs for their own use during the study and for at least 7 months after the last dose of the study drug. They should also avoid breastfeeding during this time. They may consider preserving eggs before joining the study.
  • Be at least 18 years old, or older if local laws require a higher age for consent.
  • Have HER2-positive breast cancer, meeting all criteria listed in the study protocol. HER2-positive means the cancer has a protein that promotes its growth.
  • Have a confirmed diagnosis of invasive breast cancer at the time of disease presentation. This includes inflammatory breast cancer if all other criteria are met.
  • Have a clinical stage of T1-4, N0-3, M0 before starting treatment. This describes the size and spread of the cancer.
  • Have evidence of remaining invasive cancer in the breast or lymph nodes after completing initial therapy, meeting high-risk criteria in the protocol.
  • Complete initial systemic therapy, including chemotherapy and HER2-targeted treatment, before surgery.
  • Have had adequate surgical removal of all visible cancer in the breast and lymph nodes, as confirmed by medical records.
  • Have no more than 12 weeks between the last surgery and joining the study.

Who cannot join the trial?

10 criteria

  • Patients who have a different type of cancer that is not **HER2-Positive Breast Cancer**.
  • Patients who are not considered to be at **high risk** for their breast cancer.
  • Patients who are not within the specified age range for the study.
  • Patients who are not able to follow the study procedures or take the study medication as required.
  • Patients who have other serious health conditions that might interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial recently.
  • Patients who have allergies or reactions to the study medications.
  • Patients who have not recovered from previous cancer treatments.
  • Patients who have certain infections or diseases that could affect the study results.
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Investigated drugs

  • Trastuzumab Deruxtecan (T-DXd)

    is a medication used in this clinical trial to treat patients with high-risk HER2-positive primary breast cancer. It is designed to target and attach to the HER2 protein on cancer cells, delivering a chemotherapy drug directly to the cancer cells to help destroy them. This medication is being tested to see if it is more effective than the current standard treatment in preventing the return of cancer after initial therapy.

  • Trastuzumab Emtansine (T-DM1)

    is another medication used in the trial as a comparison to Trastuzumab Deruxtecan. It is also used to treat HER2-positive breast cancer and works by combining a targeted therapy with chemotherapy. The targeted therapy part attaches to the HER2 protein on cancer cells, while the chemotherapy part helps to kill the cancer cells. This medication is the current standard treatment for patients with residual invasive disease after initial therapy, and the trial aims to compare its effectiveness with the new treatment.

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 high-risk HER2-positive breast cancer. It is designed to target and destroy cancer cells by binding to the HER2 protein, which is overexpressed in some breast cancers, and delivering a cytotoxic agent directly into the cancer cells. Trastuzumab Deruxtecan is classified as an antibody-drug conjugate, combining targeted therapy with chemotherapy to enhance its cancer-fighting capabilities.

  • Trastuzumab Emtansine

    This medication is also given through intravenous infusion and is used in the treatment of HER2-positive breast cancer, particularly in patients who have residual invasive disease after initial therapy. It works by attaching to the HER2 protein on cancer cells and releasing a chemotherapy drug directly into the cells, thereby inhibiting their growth and survival. Trastuzumab Emtansine is categorized as an antibody-drug conjugate, offering a targeted approach to chemotherapy by linking a monoclonal antibody with a cytotoxic agent.

Investigated diseases

High-Risk HER2-Positive Breast Cancer – This is a type of breast cancer characterized by the overexpression of the HER2 protein, which promotes the growth of cancer cells. It is considered high-risk due to factors such as large tumor size, lymph node involvement, or aggressive tumor behavior. The disease can progress by spreading to nearby lymph nodes and potentially to other parts of the body. Patients with this type of cancer may experience a recurrence of the disease, either locally or in distant organs. The progression of the disease is monitored through clinical assessments to detect any invasive recurrence or new cancer development.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-507961-24-00Protocol codeDS8201-A-U305Estimated enrolment1 600 patientsSponsorDaiichi Sankyo Inc.

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