A Study of Trilaciclib Combined With Chemotherapy in the Treatment of Advanced NSCLC With Leptomeningeal Metastasis

Inclusion Criteria: * must be at least 18 years when fisrt dose of Trilaciclib, regardless of gender； * ECOG-PS score of 0-1，and no worsening in the 2 weeks before the study drug； * expected survival≥12 weeks； * Advanced non-small cell lung cancer with leptomeningeal metastasis； * with an Ommaya sac has been implanted； * At least one measurable lesion meeting RECIST1.1 criteria was present； * Laboratory tests met the following criteria: hemoglobin ≥100 g/L (female), 110g/L (male) ；neutrophil count ≥ 2×109/L ；platelet count ≥100×109/L; Creatinine ≤ 15mg/L or creatinine clearance (CrCl) ≥ 60 mL/min (Cockcroft-Gault formula); Total bilirubin ≤ 1.5× upper limit of normal value (ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 3 × ULN or 5× ULN (for patients with liver metastases); Albumin ≥ 30 g/L; * Patients of reproductive age(including female and male patients'female companions)must use effective birth control measures; * Voluntarily participate and sign informed consent; Exclusion Criteria: * Patients of reproductive age(including female and male patients'female companions)must use effective birth control measures; * Stroke or cardio-cerebrovascular event within 6 months before enrollment; * QTcF interval \> 480msec at screening, QTcF \> 500msec for patients with implanted ventricular pacemakers; * Previous hematopoietic stem cell or bone marrow transplantation; * Allergy to the study drug or its components; * If the investigator considers that it is not suitable to participate in this study.