Zanidatamab is given through a vein, while tucatinib and capecitabine are taken by mouth. Eribulin mesylate is also given through a vein. The study begins with a small part where the treatment doses are worked out and checked for safety. After that, more people receive the chosen treatment plan for a longer time. During the study, the cancer and any side effects are watched over time, and treatment may continue as long as it is helping and is tolerated.

Some people may also receive medicines used to help with symptoms or side effects, such as diphenhydramine hydrochloride, loperamide hydrochloride, paracetamol, hydrocortisone sodium succinate, dexamethasone sodium phosphate, and capecitabine or eribulin mesylate depending on the treatment group. A CT scan, which is a type of body image test, may be used during the study to look at the cancer. The study is planned to run from 2026 to 2028.

Participants in the study will receive a combination of medications. One group will take RO7771950 along with trastuzumab and capecitabine. The other group will receive tucatinib combined with trastuzumab and capecitabine. The trastuzumab may be given through an IV infusion, which is a liquid medicine delivered directly into a vein, or as a subcutaneous injection, which is administered just under the skin. The other medications are taken as an oral tablet by mouth.

During the study, medical professionals will monitor how the treatments affect the cancer and how the body responds over time. The research will look at how long the cancer stays stable without growing, a measure known as progression-free survival. Other aspects of the study include monitoring overall survival, how much the tumors shrink, and any side effects experienced during the treatment period.

The purpose of this study is to see if the new radioactive tracer can predict whether the cancer will completely disappear after neoadjuvant chemotherapy. The imaging method used is called PET/CT, which stands for positron emission tomography combined with computed tomography, a type of scan that creates detailed pictures of the inside of the body. The study aims to determine if this imaging technique can accurately show when patients have achieved a complete response to treatment, meaning no invasive cancer cells remain in the breast or lymph nodes after chemotherapy.

During the study, patients will receive the radioactive tracer injection and undergo PET/CT scans to see how well the tracer binds to the cancer cells. After completing the neoadjuvant chemotherapy treatment, patients will have surgery as planned by their doctors. The results from the imaging scans will then be compared with the actual findings from the tissue examination after surgery to see if the new imaging method was able to correctly predict whether the cancer had completely responded to the chemotherapy treatment.

The purpose of this study is to see how well the combination of trastuzumab deruxtecan and pertuzumab works as a first treatment for this type of breast cancer when using digital tools to actively manage side effects, and to understand how this treatment affects quality of life. During the study, patients will receive the study medications every three weeks through infusion. They will use a smartphone application to regularly track their symptoms, medication intake, and overall well-being. The digital platform can send alerts to doctors if symptoms become severe or worsen, allowing the medical team to adjust care quickly. Some patients may also have access to optional support programs through the app, such as help with fatigue, physical activity guidance, and meditation, depending on their country. Patients will need to have a smartphone with internet access that meets specific technical requirements to use these digital tools.

The study will measure several things, including how long it takes before patients need to start a different cancer treatment, and how long it takes for physical functioning to worsen based on quality of life questionnaires. Doctors will also track side effects, how often doses need to be adjusted, how well patients can continue treatment, and how often patients need emergency visits or hospitalizations. The study will look at how the cancer responds to treatment, including whether tumors shrink or disappear, and how long any response lasts. Quality of life will be measured using questionnaires that ask about physical symptoms, daily functioning, and overall health status. The study will also track how well patients use the digital health tools and how satisfied they are with the monitoring system and the care they receive.

The main medications being tested include several cancer drugs: trastuzumab, pertuzumab, docetaxel, carboplatin, cyclophosphamide, doxorubicin, epirubicin, paclitaxel, and trastuzumab emtansine. These medications will be given through intravenous infusion or injection before surgery (neoadjuvant treatment). The treatment plan will be customized based on the results of the HER2DX test in one group of patients, while the other group will receive standard treatment.

The study will measure how treatment affects patients’ overall health status and energy levels using quality of life questionnaires. It will also evaluate how well the tumors respond to treatment and monitor patients for any side effects. The trial is expected to last approximately three years.

The study involves several medications that target HER2-positive breast cancer. Patients will receive trastuzumab emtansine (also known as T-DM1) as treatment. Before starting treatment, patients will undergo imaging with a specially modified version of trastuzumab that has been labeled with a radioactive substance to help create detailed images of the cancer. This imaging helps doctors understand how the cancer might respond to treatment.

During the study, patients will receive regular medical check-ups to monitor their response to treatment. The research team will track how long the treatment remains effective and watch for any side effects. They will also collect tissue and blood samples to study how the cancer cells change over time. This information will help doctors better understand which patients are most likely to benefit from specific treatments.

The purpose of the study is to evaluate the safety and tolerability of this new treatment. Participants will receive a single dose of the treatment, and researchers will monitor how the treatment is distributed in the body, particularly in tumors and important organs. The study is divided into two parts, and participants will be randomly assigned to one of these parts. Throughout the study, participants will undergo various tests and assessments to ensure their safety and to gather information on how the treatment affects their body.

Participants will be closely monitored for any side effects or changes in their health, including vital signs and heart function. The study will also measure how much of the treatment is absorbed by different organs and tumors. This information will help researchers understand the potential benefits and risks of [177Lu]Lu-ABY-271 for treating HER2-positive metastatic breast cancer. The trial aims to provide valuable insights into the treatment’s effectiveness and safety, contributing to the development of new therapies for this type of cancer.

The purpose of this research is to determine how effectively the treatment clears disease markers from the blood. The study involves comparing two groups of patients – one group receiving trastuzumab deruxtecan and another group receiving standard care treatment. During the study, patients will receive regular infusions of the medication and undergo blood tests to monitor their response to treatment.

The treatment may continue for up to one year, with a maximum dose of 5.4 milligrams per kilogram of body weight. Throughout the study period, patients will have regular check-ups to monitor their health and complete quality of life questionnaires. The medical team will pay special attention to monitoring the heart and lungs, as these are important aspects of patient safety during treatment.

The study uses several medications that target HER2-positive breast cancer. The main treatment being studied is trastuzumab emtansine (also known as T-DM1), which is given through an infusion into a vein. This medication combines two parts – one that targets cancer cells and another that helps destroy them. Another medication used in the study is Herceptin, which is also given through an infusion.

The purpose is to understand how cancer cells change after previous treatments and to see how well T-DM1 works in patients whose special scans show certain results. The study involves getting scans, blood tests, and tissue samples to examine the cancer in detail. Patients will receive treatment and be monitored to see how their cancer responds to the medication.

The purpose of the study is to find the best dose of BB-1701 and to see how safe and effective it is for people who have already received treatment for their cancer. The study will be conducted in two parts. In the first part, different doses of BB-1701 will be tested to find the most suitable one. In the second part, the chosen dose will be given to more participants to further evaluate its effects. Participants will receive the treatment through an infusion, which means the medication will be given directly into a vein.

Throughout the study, the safety of BB-1701 will be closely monitored by checking for any side effects and conducting regular health assessments. The effectiveness of the treatment will be evaluated by observing how the cancer responds to the medication. This includes looking at whether the cancer shrinks or stops growing. The study aims to provide valuable information about the potential benefits of BB-1701 for treating HER2-positive or HER2-low metastatic breast cancer.

The purpose of this study is to evaluate how well this combination of medications works in treating patients with this specific type of breast cancer. Participants in the study will receive the treatment over a period of time, and their response to the treatment will be monitored. The study will look at how the cancer responds to the treatment, including whether it shrinks or stops growing, and how long these effects last. The study will also monitor the overall health and survival of the participants during and after the treatment period.

Throughout the study, participants will receive regular check-ups and assessments to track their progress and any side effects they may experience. The study aims to provide valuable information on the potential benefits of this treatment combination for patients with HER2-positive breast cancer, particularly those who have not responded to previous treatments. This research could lead to new treatment options for patients with this challenging form of cancer.

The medication being tested, fadraciclib, is taken by mouth in tablet form. It belongs to a group of drugs called CDK2/9 inhibitors, which work by blocking certain proteins that help cancer cells grow. The study aims to find the best dose of the medication and determine how well it works in treating these different types of cancer.

During the study, participants take the medication either once or twice daily in 28-day cycles. The treatment continues as long as it is helping and the side effects are manageable. Throughout the study, doctors monitor the participants’ health and how their cancer responds to the treatment. This includes regular check-ups and various medical tests to ensure safety and track the effectiveness of the medication.

Participants in the study will receive the treatment combinations, and their health will be monitored to assess how well they tolerate the medications. The study will also help determine the recommended doses of ELVN-002 when used with trastuzumab and chemotherapy. The trial is divided into two phases: Phase 1a, which focuses on safety and dose determination, and Phase 1b, which continues to evaluate safety and tolerability in a broader group of patients.

The study will involve regular check-ups and monitoring to ensure the safety of participants. This includes looking for any side effects or changes in health status. The trial aims to provide valuable information on the potential benefits and risks of using ELVN-002 in combination with other treatments for HER2-positive cancers. The estimated completion date for the study is in 2027.

The purpose of the study is to evaluate the effectiveness and safety of this treatment approach in patients who have not received prior treatment for their HER2-positive breast cancer. Participants in the study will receive the medications through injections, with Phesgo being administered under the skin (subcutaneous use) and trastuzumab emtansine being given through a vein (intravenous use). The study will monitor patients over a period of time to assess how well the treatment works in preventing the cancer from returning and to evaluate any potential side effects on the patients’ overall health.

Throughout the study, participants will undergo regular health assessments, including imaging tests like MRI to track the response of the cancer to the treatment. The study aims to provide insights into whether this chemotherapy-free approach can effectively manage HER2-positive early-stage breast cancer while maintaining the patients’ quality of life. The trial will also look at the long-term outcomes, such as the recurrence of cancer and overall survival rates, to determine the potential benefits of this treatment strategy.

The purpose of this research is to understand how well trastuzumab deruxtecan works in treating advanced breast cancer patients, particularly looking at its effects in patients whose cancer has spread to the brain and those whose cancer has not. The medicine will be given to patients who have already received previous treatments for their breast cancer.

During the study, participants will receive regular doses of trastuzumab deruxtecan through infusions. Doctors will monitor how the cancer responds to treatment and track any changes in both the body and, if present, in the brain. The study will also look at how the treatment affects patients’ daily lives and overall well-being, including any side effects that may occur during treatment.

The purpose of the study is to explore whether a short course of immunotherapy, which is a type of treatment that helps the immune system fight cancer, can increase the activity of certain immune cells in the body. The study will compare the effects of these medications on the immune system before and after treatment. Participants will receive the treatment before their standard cancer therapy, and the study will involve taking samples from the tumor to analyze changes in immune cell activity.

Throughout the study, participants will receive the medications intravenously, and their health will be monitored closely. The study aims to understand how these medications affect the immune system and whether they can improve the body’s ability to fight cancer. The trial will also look at any side effects that may occur during the treatment period and up to four weeks after surgery. This research could provide valuable insights into new ways to treat early-stage breast cancer.

Participants in the study will receive one of three different treatment plans. The first plan involves taking neratinib along with loperamide from the start. The second plan includes starting with a lower dose of neratinib and increasing it gradually, with loperamide given as needed. The third plan combines neratinib with both loperamide and colesevelam. The purpose of these different approaches is to find the best way to reduce the number of patients who stop taking neratinib due to diarrhea.

The study will last for a maximum of 12 months, during which participants will be monitored for any side effects and how they respond to the treatment. The goal is to improve the management of side effects so that patients can continue their cancer treatment with fewer interruptions. This research is important for finding better ways to support patients with HER2-positive, hormone receptor-positive early-stage breast cancer in their treatment journey.

The purpose of the study is to explore how changes in the cancer cells’ genetic material, which can lead to resistance to the treatment, can be detected using a new method called liquid biopsy. This involves taking blood samples to look for changes in the cancer cells’ DNA that are circulating in the blood. The study will monitor these changes over time to understand how they relate to the effectiveness of the treatment.

Participants in the study will receive the treatment and have regular blood tests to check for changes in the cancer cells’ DNA. The study will last for a period of time, during which the safety and effects of the treatment will be closely monitored. The goal is to better understand how to tailor treatments for patients with this type of breast cancer and improve outcomes by using advanced diagnostic methods like liquid biopsy.

The purpose of the study is to evaluate the safety and feasibility of this chemotherapy-free treatment regimen in patients with stage II-III HER2-positive breast cancer. Participants in the study will receive the medications before surgery, a phase known as neoadjuvant treatment. The study will monitor the participants for any side effects and assess how well the cancer responds to the treatment. The medications are administered in different forms: trastuzumab and pertuzumab are given as solutions for infusion, which means they are delivered directly into the bloodstream through a vein, while tucatinib is taken orally as a tablet.

The study will follow participants through their treatment journey, observing any changes in the cancer and recording any adverse effects. The goal is to determine if this combination of medications can effectively treat HER2-positive breast cancer without the need for chemotherapy, which often comes with significant side effects. The study will also look at the long-term outcomes, such as the absence of cancer at the time of surgery and overall survival rates, to provide a comprehensive understanding of the treatment’s impact.

The purpose of the study is to assess how effective and safe GLSI-100 is for patients who have completed standard breast cancer treatments but still have a high risk of the cancer returning. Participants in the study will receive either the GLSI-100 treatment or a placebo. The study will last for a period of time, during which participants will receive regular injections and attend follow-up visits to monitor their health and the effects of the treatment.

Throughout the study, participants will be closely monitored for any changes in their condition, including any side effects or improvements. The study aims to provide valuable information on whether GLSI-100 can help reduce the risk of breast cancer coming back in patients who have already undergone extensive treatment. This research could potentially lead to new treatment options for individuals with high-risk breast cancer.

The purpose of the study is to provide continued access to this treatment for patients who are benefiting from it and to monitor its long-term safety. Participants in this study will continue to receive the medication as long as they are experiencing positive effects from it. The study will track any side effects or health changes that occur during this time.

Throughout the study, participants will receive regular infusions of the medication and will be monitored by healthcare professionals to ensure their safety. The study aims to gather information on any adverse events, which are unexpected health issues that might arise from the treatment. This information will help in understanding the long-term effects of the medication and ensuring it is safe for continued use in treating these types of cancers.

The purpose of the study is to provide continued treatment to patients who have previously benefited from these therapies in earlier studies. The trial aims to gather information on the safety of long-term use of trastuzumab emtansine, whether used alone or with other medications. Patients who have shown positive results from previous treatments with these drugs are given the opportunity to continue their therapy in this extension study.

Participants in the study will receive their treatment through an intravenous infusion, which means the medication is delivered directly into the bloodstream through a vein. The study will monitor patients over a period to assess the safety and any side effects of the treatments. This trial is designed to ensure that patients who have responded well to these medications can continue to receive them and to collect valuable data on their long-term use.

The purpose of the study is to determine how well atezolizumab works when given with trastuzumab emtansine, compared to trastuzumab emtansine alone. Participants in the study will receive one of these treatments after they have completed their initial therapy for breast cancer. The study will monitor participants over a period of time to assess their health and any changes in their condition. This will help researchers understand the potential benefits and risks of the treatments.

Participants will be randomly assigned to receive either the combination of atezolizumab and trastuzumab emtansine, trastuzumab emtansine with a placebo, or other variations as part of the study. The treatments will be administered through an infusion, which is a method of delivering medication directly into the bloodstream. The study aims to provide valuable information on the effectiveness of these treatments in preventing the recurrence of breast cancer in patients who are at high risk.

The purpose of this study is to determine how effective the addition of tucatinib is when combined with pertuzumab and trastuzumab in treating brain metastases. The treatment begins after patients have completed local treatment of their brain tumors through surgery and/or radiation therapy. Patients will receive regular brain scans to monitor how their cancer responds to the treatment.

Throughout the study, patients will take tucatinib tablets daily and receive regular infusions of pertuzumab and trastuzumab. The treatment will continue as long as it remains effective and the side effects are manageable. Patients will have regular check-ups to monitor their health and assess how well the treatment is working. Some patients may also receive additional hormone-blocking treatments such as anastrozole, letrozole, exemestane, or fulvestrant, depending on their specific type of breast cancer.

The purpose of the study is to see how well the treatment works in preventing the cancer from progressing, which means getting worse or spreading. Participants in the study will receive either the combination of medications or a placebo, and their health will be monitored over time. The study will involve regular check-ups and assessments to track the progress of the disease and any side effects of the treatment. The trial aims to provide more information on how effective this treatment is in managing advanced or metastatic HER2-positive breast cancer.

Throughout the study, participants will undergo various tests and evaluations, including imaging tests like MRI to check for any changes in the brain, as some patients may have brain metastases, which are cancer cells that have spread to the brain. The study will also look at the overall survival of participants, which is the length of time they live after starting the study, and their quality of life during the treatment. The trial is expected to continue for several years to gather enough data to determine the effectiveness of the treatment.

The cancer treatment in this study involves two steps. First, patients receive a drug called trastuzumab deruxtecan, which is given as an intravenous infusion. This is used as an initial or induction treatment. After this, the study uses a combination of drugs called Phesgo, which includes two active ingredients: trastuzumab and pertuzumab. Phesgo is given as an injection and is used to maintain the treatment’s effects after trastuzumab deruxtecan.

The main purpose of this study is to check how long patients can live without the cancer getting worse after one year and the overall survival at three years. Participants in this study have not received chemotherapy or treatments targeting HER2 for their advanced cancer before. The study aims to provide insights into whether the treatment can help control cancer growth and improve patients’ survival.

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.

Participants in the study will receive Disitamab Vedotin, which is given as an infusion, meaning it is administered directly into the bloodstream through a vein. Tucatinib is taken as a tablet by mouth. The study will explore how these treatments work in different groups of patients, including those with HER2-low and HER2-positive breast cancer, as well as those with HER2-low gastric cancer. HER2 is a protein that can affect the growth of cancer cells, and the study will look at how the treatments perform in patients with varying levels of this protein.

Throughout the study, researchers will monitor participants for any side effects and will assess how well the cancer responds to the treatment. The study aims to gather information on the safety of the treatments and their ability to control or reduce the cancer. This information will help determine the potential benefits of using Disitamab Vedotin and Tucatinib for these types of cancer.

The study will be conducted in two main parts. In the first part, researchers will determine the best dose of the drug combinations to use. This is known as the dose-finding phase. In the second part, the study will expand to include more patients to further evaluate the safety and effectiveness of the treatment at the determined dose. This is called the dose-expansion phase. The study will include patients who have already received treatment for their cancer as well as those who have not yet been treated for advanced or metastatic disease.

Throughout the study, participants will receive the treatments either orally or through an infusion, which is a method of delivering medication directly into the bloodstream. The study aims to provide valuable information on how these drug combinations can help manage HER2-positive Metastatic Breast Cancer, including patients with brain metastases, which are cancer cells that have spread to the brain. The study is expected to continue until 2025, with recruitment starting in 2024.

Participants in this study will receive pertuzumab, and possibly trastuzumab, through an intravenous (IV) infusion, which means the medication is delivered directly into the bloodstream through a vein. The study is designed to monitor the safety and effectiveness of the treatment over time. Patients will be observed for any adverse events, which are unwanted effects that may occur during treatment. The study will also assess how long patients live without their cancer getting worse, known as progression-free survival, and overall survival, which is the length of time patients live after starting the treatment.

This study is an extension of a previous trial, meaning it continues the treatment for patients who were already receiving pertuzumab and were benefiting from it. The trial is open-label, which means both the researchers and participants know which treatment is being administered. The study aims to provide ongoing access to pertuzumab for those who need it, ensuring that patients continue to receive the potential benefits of the therapy.

The purpose of the study is to evaluate how effective this combination of medications is in treating the cancer. Participants in the study will receive the combination of these medications, and some may receive a placebo. The study will monitor the participants over a period of time to observe the response of the cancer to the treatment. This includes looking at how the cancer shrinks or grows, and how long the effects of the treatment last. The study will also assess the safety of the treatment by monitoring any side effects that participants may experience.

Throughout the study, participants will undergo various assessments, including imaging tests like MRI to check for any changes in the cancer, especially in the brain if there are concerns about metastasis, which is when cancer spreads to other parts of the body. The study aims to provide valuable information on the potential benefits and risks of using this combination of medications for treating HER2-positive breast cancer.

The purpose of the study is to determine the best dose of Ipatasertib when used in combination with Trastuzumab and Pertuzumab. Participants will receive these medications in different forms: Ipatasertib as a tablet taken by mouth, Trastuzumab as a solution for injection or infusion, and Pertuzumab as a solution for infusion. The study will monitor how patients respond to the treatment and any side effects they may experience. The trial will also assess how long the treatment can keep the cancer from getting worse.

Throughout the study, participants will receive regular check-ups to monitor their health and the effectiveness of the treatment. The study aims to find the most effective and safe dose of Ipatasertib in combination with the other medications, which could potentially lead to better treatment options for patients with this type of breast cancer. The trial is expected to continue until December 2025.

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 purpose of the study is to understand how effective this treatment is in reducing cancer in the breast and nearby lymph nodes before surgery. The study also aims to see how well patients do over a period of three years without the cancer coming back. To help guide the treatment, doctors will use a special type of scan called FDG-PET, which helps to see how the cancer is responding to the treatment early on. This scan uses a small amount of radioactive sugar to highlight areas of cancer activity in the body.

Participants in the study will receive the treatment over a period of up to 90 days. The study will monitor the effects of the treatment on the cancer and assess the overall health and quality of life of the participants. The goal is to find out if this chemotherapy-free approach can be a successful treatment option for patients with HER2-positive breast cancer.

The purpose of the study is to evaluate how effective trastuzumab deruxtecan is when used as part of a combination treatment approach for patients with HER2-positive oligometastatic breast cancer. Participants in the study will receive the medication and will be monitored over a period of time to assess the treatment’s impact on their cancer. The study will also involve regular imaging tests, such as MRI and PET-CT, to track changes in the cancer and determine the treatment’s effectiveness.

Throughout the study, researchers will be looking for a complete response to the treatment, which means that the cancer is no longer detectable on imaging tests. They will also monitor for any side effects that participants may experience. The study aims to provide valuable information on the potential benefits of trastuzumab deruxtecan for patients with this specific type of breast cancer.

The purpose of the study is to understand how much time healthcare providers and patients can save when using the new injection method compared to the traditional infusion method. Participants in the study will receive the treatment over several cycles, and the time taken for each method will be measured. This includes the time spent by healthcare providers in preparing and administering the treatment, as well as the time patients spend in the treatment chair and in the hospital.

The study will also look at the safety and tolerability of the new injection method compared to the traditional infusion method. This means checking for any side effects or reactions that might occur with the new treatment. The study aims to provide valuable information on whether the new method can make the treatment process more efficient and comfortable for patients with .

The purpose of this study is to compare the effectiveness and safety of giredestrant combined with Phesgo versus Phesgo alone. The study will first give all participants an induction treatment phase consisting of Phesgo combined with a taxane chemotherapy. After this initial treatment phase, participants will be randomly assigned to receive either Phesgo combined with giredestrant or Phesgo alone. The study will measure how long participants live without their cancer getting worse, as well as overall survival time, how well the cancer responds to treatment, and the duration of that response.

During the study, participants will be monitored for side effects and changes in their health status. The study will also assess quality of life and how well participants are able to function in their daily activities using standardized questionnaires. Blood tests and other clinical assessments will be performed regularly to monitor safety throughout the treatment period.

The purpose of the study is to compare the effectiveness of standard treatments with T-DXd in patients with HER2-positive breast cancer. Participants will receive either the standard treatment or T-DXd. The study will monitor the response to these treatments, focusing on how well the cancer responds and whether it disappears completely in the treated area. The study will also look at the overall health and survival of the participants over time.

Participants in the study will receive their assigned treatment and will be monitored regularly by healthcare professionals. The study will track the progress of the cancer and any side effects from the treatments. The goal is to determine which treatment is more effective in treating HER2-positive breast cancer and to gather information that could help improve future treatment options for this type of cancer.

The purpose of the study is to evaluate how well trastuzumab deruxtecan works in patients whose cancer has not responded well to previous treatments, specifically those involving trastuzumab, pertuzumab, and taxane. Participants in the study will receive the medication through an intravenous infusion, which means it will be administered directly into a vein. The study will monitor the participants over a period to assess the treatment’s impact on the cancer, including how long it takes for the cancer to progress and the overall survival of the patients.

Throughout the study, researchers will also keep track of any side effects or adverse reactions to the treatment. This will help determine the safety and tolerability of trastuzumab deruxtecan. The study aims to provide valuable information on whether this treatment can be a viable option for patients with HER2-positive metastatic breast cancer who have not had success with other therapies.

Participants in the study will undergo a period of reduced treatment to see if their cancer remains controlled. This approach is known as therapeutic de-escalation. The study will monitor the patients’ health and cancer status over time to determine if the reduced treatment is effective. The study will also involve regular blood tests to check for any signs of cancer returning. If the cancer does show signs of returning, the original treatment may be reintroduced. The study aims to find out if it is safe and effective to give patients less medication while still keeping the cancer under control.

The study will last for a maximum of 36 months, during which time patients will be closely monitored. The main goal is to see if the cancer remains stable without the full intensity of the original treatment. This could potentially lead to fewer side effects and an improved quality of life for patients. The study will also assess the overall health and well-being of participants, including their quality of life and any feelings of anxiety or regret about their treatment decisions. The results of this study could help guide future treatment plans for patients with HER2-positive metastatic breast cancer.