Leptomeningeal metastases (LM) is a lethal complication of malignant tumors, characterized by tumor cell invasion and proliferation within the subarachnoid space. LM from HER2-negative breast cancer remains challenging to treat, with a median overall survival of only 3-6 months despite aggressive therapy. This open-label, uncontrolled Phase I/II clinical study aims to evaluate the safety, feasibility, and potential efficacy of Sacituzumab Govitecan in combination with intrathecal pemetrexed chemotherapy for LM from HER2-negative breast cancer, with the objective of identifying a more effective treatment strategy.
A clear histopathologic diagnosis of breast cancer with HER2-negative subtype (including IHC 0, IHC 1+ or IHC 2+ and ISH negative);
Cerebrospinal fluid cytology confirms the presence of leptomeningeal metastases; or imaging findings combined with clinical symptoms and signs are consistent with the diagnosis of leptomeningeal metastases;
Age ≥ 18 years old.
Inadequate organ function: 1) Blood tests: ANC ≤ 1.5 x 10^9/L, PLT ≤ 90 x 10^9/L, Hb ≤ 90 g/L; 2) Blood biochemistry tests: TBIL ≥ 1.5 times the upper limit of normal; 3) ALT and AST ≥ 2.5 times the upper limit of normal;
Presence of serious and/or uncontrolled comorbidities that may affect participation: 1) Allergy to study drugs or adjuvant materials; 2) History of immunodeficiency (e.g., HIV-positive or other acquired or congenital immunodeficiency disease); 3) Severe concomitant diseases;
Pregnant and breastfeeding female patients; women of childbearing age who are unwilling or unable to use effective contraception;
Any other condition that, in the opinion of the investigator, makes the patient ineligible for participation in the study.