SHR-A1811 and THPy in First or Second Line for HER2 Positive Advanced Breast Cancer Brain Metastases

Inclusion criteria

• Females ≥18 yrs old
• Pathologically confirmed HER2-positive advanced breast cancer;
• Newly diagnosed brain metastes,At least one measurable intracranial lesion
• Not received any systemic treatment for advanced stage
• Radiotherapy was allowed in patients with an urgent need for control of intracranial symptoms
• Adequate function of major organs
• Willing to join in this study, able to provide written informed consent, good compliance and willing to cooperate with follow-up.

Exclusion criteria

1.Has leptomeningeal metastasis or cystic metastatic lesions confirmed by MRI or lumbar puncture; 2.Existence of third space fluid (e.g. massive ascites, pleural effusion, pericardial effusion) that is not well controlled by effective methods, e.g. drainage; 3.Has received whole brain radiotherapy, chemotherapy, surgery within 2 weeks before first dose of study therapy; 4.Has known clinically significant lung disease, that is, moderate-to-severe lung disease which severely affects respiratory function, including but not limited to: idiopathic pulmonary fibrosis, pneumonitis. Prior ≥ grade 3 interstitial lung disease is not allowed to enrolment; 5.Has received full-dose anticoagulants or thrombolytics within 10 days before enrolment, or non-steroid anti-inflammatory drugs with platelet inhibition 6.Previous treatment with trastuzumab deruxtecan (DS-8201a) or any other antibody drug conjugate (ADC) which consists of an exatecan derivative that is a topoisomerase 1 inhibitor; 7.Participated in other drug clinical trials within 4 weeks before admission; 8.Other malignant tumors, excluding cured cervical carcinoma in situ, skin basal cell carcinoma or skin squamous cell carcinoma, have been diagnosed in the past five years.

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