A Prospective, Multicenter, Randomized Controlled Phase II Study to Evaluate the Efficacy and Safety of PD-L1 Monoclonal Antibody Combined With VEX Metronomic Chemotherapy and Concurrent or Delayed Radiotherapy in Patients With Advanced HER2-Negative Breast Cancer With Brain Metastasis
A Prospective, multicenter, randomized controlled phase II study to evaluate the efficacy and safety of PD-L1 monoclonal antibody combined with vinorelbine + cyclophosphamide + capecitabine (VEX) metronomic chemotherapy and concurrent or delayed radiotherapy in patients with advanced HER2-negative breast cancer with brain metastasis
• Males or females who are at least 18 years of age on the day of signing the informed consent form.
• Patients with metastatic HER2-negative breast cancer brain metastasis, with clear clinical documentation; specific criteria refer to the guidelines of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP).
• Patients who have received no more than one line of chemotherapy during the metastatic stage of breast cancer.
• Patients with brain metastasis should not require immediate local therapy during the trial and meet at least one of the following criteria:
∙ The patient has not previously received intracranial radiotherapy.
‣ The patient has not previously undergone surgery for intracranial metastases; if surgery was performed, the surgical lesion is not the target for the planned radiotherapy, or it is the target lesion and has recurred after surgery.
• The patient must have at least one measurable intracranial lesion, with the longest diameter baseline accurately measurable by magnetic resonance imaging (MRI) as ≥10 mm and suitable for precise repeated measurement according to RECIST 1.1 in combination with RANO criteria. Measurable extracranial lesions are not required.
• Patients with suspected or confirmed leptomeningeal metastasis should be excluded.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, assessed within 10 days before the start of study treatment.
• Patients may have previously received anthracycline (e.g., doxorubicin, epirubicin) and/or taxane (e.g., paclitaxel, docetaxel) therapy, specifically including:
∙ Before breast cancer recurrence, the patient received anthracycline and/or taxane during adjuvant or neoadjuvant treatment.
‣ The patient experienced treatment failure during or after anthracycline and/or taxane-based chemotherapy.
‣ In the judgment of the investigator, the patient is not suitable for anthracycline and/or taxane-based chemotherapy as a first-line treatment regimen.
• Female patients are not pregnant, not breastfeeding, and agree to use necessary contraceptive measures.
⁃ The patient is able to sign the informed consent form to participate in the study.
⁃ The patient has adequate organ function, as detailed in Table 1 of the study protocol; all screening laboratory tests should be completed within 10 days before the start of study treatment.