U.S., June 18 -- ClinicalTrials.gov registry received information related to the study (NCT07653893) titled 'A Phase II Observational Clinical Study on the Relationship Between Cerebrospinal Fluid Drug Concentration and Efficacy of Trastuzumab Deruxtecan in Central Nervous System Metastatic Breast Cancer' on June 26, 2025.

Brief Summary: Approximately 5-15% breast cancer patients develop brain metastases. Current local treatments (surgery/radiotherapy) are associated with significant complications, and systemic treatments have limited efficacy. Although new-generation ADC drugs, such as trastuzumab deruxtecan, have demonstrated breakthrough efficacy in patients with brain metastases, the mechanisms of action are not fully elucidated, moreo...