Safety and Efficacy of Intrathecal Sacituzumab Tirumotecan for Leptomeningeal Metastasis in EGFR-TKI-Resistant Non-Small Cell Lung Cancer

Inclusion Criteria:

Age ≥ 18 years;

Pathologically diagnosed as EGFR mutation-positive non-small cell lung cancer;

Leptomeningeal metastasis confirmed by detection of tumor cells in cerebrospinal fluid cytology;

Previously received targeted therapy against EGFR mutation and progressed;

ECOG performance status ≤ 3;

Neurological symptoms stable for more than 7 days (defined as no new or worsening neurological symptoms and no more than a 1-point change in ECOG score);

If radiotherapy (including whole-brain radiotherapy, stereotactic radiotherapy, etc.) has been received, at least 7 days after completion; if other intrathecal therapy has been received, a washout period of at least 7 days;

Absolute neutrophil count ≥ 1.5 × 10⁹/L, hemoglobin ≥ 80 g/L, platelet count ≥ 75 × 10⁹/L;

Prothrombin time/international normalized ratio and partial thromboplastin time ≤ 1.5 × upper limit of normal;

Total bilirubin ≤ 1.5 × upper limit of normal, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × upper limit of normal (elevations of total bilirubin and transaminases caused by tumor may be relaxed to 3× and 5×, respectively), creatinine ≤ 2 × upper limit of normal; calculated creatinine clearance ≥ 50 mL/min.

Exclusion Criteria:

Active infectious disease within 7 days before the start of study drug treatment;

ECOG performance status ≥ 4;

History of allergy to any component of the study drug;

History of severe hypersensitivity reaction to any monoclonal antibody;

Patients currently participating in other interventional studies;

Previous or current severe immunodeficiency disease;

Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in this study.