Intrathecal PD-1/VEGF Bispecific Antibody Plus Pemetrexed for Leptomeningeal Metastasis

Inclusion Criteria: 1. Histologically or cytologically confirmed diagnosis of solid tumors;Cerebrospinal fluid cytopathology is positive. 2. Male or female aged between 21 and 75 years; Normal liver and kidney function; WBC≥4000/mm3, Plt≥100000/mm3. 3. No history of severe nervous system disease; No severe dyscrasia. Exclusion Criteria: 1. Any evidence of nervous system failure, including severe encephalopathy, grade 3 or 4 leukoencephalopathy on imaging, and Glasgow Coma Score less than 11. 2. Any evidence of extensive and lethal progressive systemic diseases without effective treatment. 3. Obvious bleeding tendency; Patients with hemorrhage (NCI-CTCAE v5.0 greater than grade 2), coagulation disorder, hypertensive crisis, and severe arterial thrombosis. 4. A history of HIV or AIDS, acute or chronic hepatitis B or C infection, previous anti-PD1 therapy-induced pneumonitis, or have ongoing \>Grade 2 adverse events of such therapy; or ongoing autoimmune disease that required systemic treatment in the past 2 years. 5. The first month to treatment, as well as during induction and consolidation therapy, new drugs effective against leptomeningeal metastases were used, excluding those previously administered. These primarily included small molecule targeted therapies, such as EGFR-TKI/ALK-TKI drugs like Osimertinib and Lorlatinib. 6. Patients with poor compliance or other reasons that were unsuitable for this study.