DESTINY Breast Respond HER2-low Europe

Study Overview
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Brief Summary
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Trastuzumab deruxtecan (T-DXd) as monotherapy is indicated for the treatment of adult patients with unresectable or metastatic HER2-low breast cancer who have received prior chemotherapy in the metastatic setting or developed disease recurrence during or within 6 months of completing adjuvant chemotherapy.

Detailed Description
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This non-interventional study will investigate the effectiveness withT-DXd, the demographic and clinical characteristics of the patients, treatment patterns, tolerability, management of adverse drug reactions (ADRs), and patient experience of T-DXd in patients with HER2-low unresectable and/or metastatic breast cancer. Patients will be treated according to the proposed indication statement in the Summary of Product Characteristics (SmPC). No drug product will be administered as part of this study. Data on conventional chemotherapy (i.e., including but not limited to capecitabine, eribulin, gemcitabine, paclitaxel and nab-paclitaxel) will also be collected in a disease registry part of the study.

Official Title
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A Prospective, Non-interventional Study (NIS) With Trastuzumab Deruxtecan For Patients With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer Accompanied By a Disease Registry of Patients Treated With Conventional Chemotherapy (DESTINY Breast Respond HER2-low Europe)

Conditions
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Unresectable Breast Cancer, Metastatic Breast Cancer, HER2-low Expressing Breast Cancer

Intervention / Treatment
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* Drug: Trastuzumab deruxtecan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patient (age ≥ 18 years) with histological or cytological confirmed diagnosis of unresectable and/or mBC Documented HER2-low status (IHC1+, IHC2+/ISH-) Patients who have received prior chemotherapy in the metastatic setting or patients who have developed disease recurrence during or within 6 months of completing adjuvant chemotherapy Decision to newly initiate therapy of T-DXd or conventional chemotherapy according to the physicians choice per SmPC Written and signed Informed Consent to participate in the study Exclusion Criteria: Pregnancy or breastfeeding Patients who at time of data collection for this study are participating in or have participated in an interventional study that remains blinded. No specific exclusion criteria are defined, as patients will be treated according to the proposed indication statements in the SmPC.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Trastuzumab deruxtecan (T-DXd)<br>Participants with HER2-low expressing unresectable and/or metastatic breast cancer who will be treated with trastuzumab deruxtecan and part of the enrolled participants will receive conventional chemotherapy. The participants on conventional chemotherapy will be analyzed exploratory only. | Drug: Trastuzumab deruxtecan<br>* This is a non-interventional study and medication will be administered according to the SmPC as local standard of care and as part of the routine clinical practice. Trastuzumab (T-DXd) to be administered according to the SmPC. Conventional therapy (eg. capecitabine, eribulin, gemcitabine, paclitaxel, nab paclitaxel) to be administered according to the SmPC.<br>* Other names: T-DXd;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Real World Time to Next Treatment (rwTTNT1) in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer |  | Baseline up to 31 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Type of Treatment Patterns in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer |  | Baseline up to 31 months | 
| Number of Physician-reported Safety Events of Interest in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer (T-DXd only) |  | Baseline up to 31 months | 
| Number of Participants Receiving Prophylactic and Reactive Treatment Management for Physician-reported Safety Events of Interest in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer (T-DXd only) |  | Baseline up to 31 months | 
| Real World Time to Permanent Treatment Discontinuation (rwTTD1) in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer |  | Baseline up to 31 months | 
| Patient's Global Impression of Treatment Tolerability (PGI-TT) in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer | The PGI-TT is designed to assess the treatment tolerability of the medicine. Participants will rate the bother associated with any treatment-related symptoms based on a 5-point scale ranging from 1 (not at all) to 5 (very much). Higher scores indicate a worse outcome. | Baseline up to 31 months | 
| European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) Score in Participants With HER2-low Expressing Unresectable and/or Metastatic Breast Cancer | The EORTC QLQ-C30 questionnaire is designed to measure cancer patients' physical, psychological and social functions. The EORTC QLQ-C30 scales and single-item scales range in score from 0 to 100. A higher score for the functioning scales and global health status denotes a better level of functioning (i.e. a better state of the patient), while higher scores on the symptom and single-item scales indicate a higher level of symptoms (i.e. a worse state of the patient). | Baseline up to 31 months | 
| Number of Participants Reporting Nausea and Vomiting as Assessed by a Patient Diary |  | Baseline up to 31 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Unresectable Breast Cancer, Metastatic Breast Cancer, HER2-low Expressing Breast Cancer, Trastuzumab Deruxtecan, Enhertu®