Sacituzumab Govitecan and Intrathecal Chemotherapy for Treating Leptomeningeal Metastases From Her2-negative Breast Cancer

Patients receive Sacituzumab Govitecan 10mg/kg by intravenous infusion on days 1 and 8. Treatment cycles are every 21 days.

Intrathecal pemetrexed chemotherapy, administered via intracerebroventricular or lumbar puncture, consists of three phases: induction therapy (15 mg twice weekly for 2 weeks), consolidation therapy (once weekly for 4 consecutive weeks), and maintenance therapy (once monthly).