Intrathecal Injection Pemetrexed And Bevacizumab in Patients With Leptomeningeal Metastases in NSCLC

Inclusion criteria

• Age ≥ 18 years;
• ECOG PS score 0-3. ECOG PS score 2 or 3 should be due to leptomeningeal metastases.
• Patients with pathologically diagnosed non-small cell lung cancer with cerebrospinal fluid and/or MRI diagnosis of leptomeningeal metastasis(LM);
• Unsatisfactory efficacy of LM,which defined as disease progression in LM,or LM-related neurological progression, while patients received standard systemic anti-tumor treatment;
• Expected survival time ≥ 1 month;
• The laboratory test results meet the following criteria:Hemoglobin ≥ 90 g/L, neutrophil count ≥ 1.5 × 10\^9/L, platelet count ≥ 100 × 10\^9/L; Total bilirubin ≤ 1.5 times the upper limit of normal (ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN ; Creatinine≤ 2.0 × ULN,or Creatinine clearance rate (CrCl) ≥ 50 mL/min;
• Females of child-bearing potential agree to use contraception during the study period and for 6 months after the completion of the study; patients who have had a negative serum or urine pregnancy test within seven days prior to enrollment in the study and who are not breastfeeding; and males agreeing to use contraception during the study period and for 6 months after the completion of the study;
• Understand and sign the informed consent form.

Exclusion criteria

• Positive for human immunodeficiency virus (HIV) ;
• History of allergy to pemetrexed or bevacizumab;
• History of pemetrexed and/or bevacizumab intrathecal Injection;
• Presence of contraindication of bevacizumab:
• Uncontrolled hypertension(systolic pressure≥150mmHg，or diastolic pressure≥100mmHg；History of hypertensive crisis or hypertensive encephalopathy;
• Urine protein≥2+,or 24-hour urine protein≥2g；
• Unstable angina pectoris, symptomatic congestive heart failure,myocardial infarction within 6 months before enrollment, severe vascular disease, severe uncontrolled arrhythmia;
• Major hemoptysis within the past 1 month; History of coagulation disorders;
• Presence of serious non-healing wounds, ulcers, or bone fractures
• Presence of abdominal fistula, gastrointestinal perforation, or gastrointestinal tract obstruction;
• Presence of macrovascular invasion；
• Some neurological disorders unrelated to tumors，such as intracranial infection,cerebral hemorrhage,cerebral infarction,encephalitis;
• Brain/spinal cord radiation therapy within 1 week before enrollment;
• Pregnant and lactating female;
• Refuse to use contraception during the study period;
• Individuals considered by the investigator to be unsuitable for enrollment.