TDXD in Metastatic HER2-Positive Breast Cancer

Study of Efficacy and Toxicity of Trastuzumab Deruxtecan in Metastatic HER2-Positive Breast Cancer Patients: Single Center Experience, Madinah, Saudi Arabia

A single-center observational study (retrospective + prospective) evaluating the real-world efficacy and toxicity profile of Trastuzumab Deruxtecan (T-DXd) in adult female patients with HER2-positive metastatic breast cancer treated at KSAMC, Madinah, Saudi Arabia

Includes patient demographics, treatment lines (2nd line or beyond), dosing schedule, response assessment per RECIST 1.1, and adverse event grading per CTCAE v5.0

Inclusion Criteria:

• Female patients aged ≥ 18 years
• Histologically confirmed HER2-positive metastatic breast cancer
• Progression during or within 6 months of finishing adjuvant anti-HER2 therapy (T-DXd as 2nd line), OR de novo metastatic disease previously treated with ≥ 2 lines of anti-HER2 therapy (T-DXd as 3rd line or beyond)
• ECOG Performance Status 0-1
• LVEF ≥ 50% on echocardiography
• Measurable lesions per RECIST v1.1
• Adequate hematologic, hepatic, and renal function

Exclusion Criteria:

• History of non-infectious interstitial lung disease (ILD) / pneumonitis requiring steroids
• Active uncontrolled infection
• Symptomatic/uncontrolled brain metastases
• Severe cardiac dysfunction (LVEF < 50%)
• Pregnancy or lactation