Basis: Brain metastasis is very common in breast cancer, and HER2 positivity is a risk factor for high incidence of brain metastasis, with approximately 50% of HER2+ MBC cases experiencing brain metastasis. The reason for this is that as the efficacy of HER2-targeted therapy improves, the survival of these patients significantly extends, leading to an increase in the occurrence rate of brain metastasis events in the late stage of MBC. In the systemic treatment of HER2+ breast cancer brain metastasis, various HER2-targeted drugs have been explored, but none have achieved satisfactory therapeutic effects. Therefore, it is imperative to explore new treatment options. ADC drugs have shown some efficacy in brain metastasis patients, and as a domestically developed ADC drug, trastuzumab vedotin has demonstrated good anti-tumor effects. The treatment model combining trastuzumab vedotin with small molecule TKIs has been rarely reported, so we are attempting to use the treatment model of trastuzumab vedotin combined with pyrotinib or neratinib to explore its efficacy and safety in patients with HER2-positive brain metastasis.
Method: The plan is to recruit HER2-positive breast cancer patients with brain metastasis and use the treatment of trastuzumab vedotin combined with pyrotinib or neratinib (specific treatment drugs to be selected during the study).
Procedure: All subjects will undergo screening, treatment, and follow-up periods, strictly adhering to relevant GCP regulations during the treatment process.
Expectations: Through this study, preliminary efficacy and safety data of trastuzumab vedotin combined with pyrotinib or neratinib treatment will be provided for patients with HER2+ brain metastatic BC.
Patients who can voluntarily sign an informed consent form;
Females aged ≥18 years old when signing the informed consent form;
ECOG PS physical status score of 0 to 2 points;
Histologically confirmed HER2-positive metastatic breast cancer patients; Note: HER2 positivity refers to at least one occurrence of tumor cell immunohistochemical staining intensity of 3+ or confirmed as positive by fluorescence in situ hybridization [FISH] in the pathological testing/re-review of the primary or metastatic lesions conducted by the participating center's pathology department;
Patients who have received treatment with anti-HER2 ADC drugs;
Patients who have received sequential treatment with pyrotinib and neratinib;
Patients with extensive leptomeningeal metastases and poor response to steroid dehydration therapy for brain metastases;
Presence of third space fluid accumulation (such as significant pleural effusion or ascites) that cannot be controlled by drainage or other methods;