To Explore the Efficacy and Safety of Double-dose Third-generation EGFR-TKI Combined With Bevacizumab and Intrathecal Chemotherapy in Advanced NSCLC Patients With Progressive Leptomeningeal Metastasis After Prior Standard-dose Third-generation EGFR-TKI Treatment.
The goal of this clinical trial is to explore the efficacy and safety of double-dose third-generation EGFR-TKI combined with bevacizumab and intrathecal chemotherapy in treating advanced non-small cell lung cancer (NSCLC) patients with leptomeningeal metastasis that progressed after prior standard-dose third-generation EGFR-TKI treatment. It also aims to investigate the correlation between cerebrospinal fluid genetic characteristics and prognosis as well as subsequent efficacy prediction in patients with leptomeningeal metastasis after resistance to standard-dose third-generation EGFR-TKI. The main questions it intends to answer are: Does this combined treatment regimen improve leptomeningeal metastasis response rate (LM-ORR) evaluated by RANO-LM? What adverse events occur in patients during the treatment with this combined regimen? Researchers will conduct a single-arm phase II prospective study to assess the effectiveness and safety of the combined treatment, without a control group comparison. Participants will: Receive double-dose third-generation EGFR-TKI (osimertinib 160mg qd, furmonertinib 160mg qd, or almonertinib 220mg qd) + intrathecal pemetrexed (induction phase: 10mg twice a week for 4 weeks; maintenance phase: 10mg once a week for 4 weeks; consolidation phase: 30mg every 4 weeks until disease progression or intolerable toxicity) + bevacizumab 7.5mg/kg. Undergo screening assessments within 28 days before enrollment, including tumor imaging, laboratory tests, and cerebrospinal fluid examination. During the treatment period, conduct regular checkups and tests (such as blood routine, blood biochemistry, electrocardiogram, and imaging examinations) according to the protocol (once every 4 weeks in the first two treatment cycles, then once every 8 weeks). Complete quality of life assessment using the QLQ-C30 scale every 4 weeks and record changes in neurological symptoms and ECOG scores.
• Aged ≥ 18 years at the time of signing the informed consent form, regardless of gender.
• Histologically or cytologically confirmed advanced or metastatic non-small cell lung cancer (NSCLC), staged as IV according to the 8th edition of the IASLC TNM classification (2015).
• Presence of EGFR-sensitive mutations (exon 19 deletion or exon 21 L858R mutation).
• Leptomeningeal metastasis (LM) progression after standard-dose first-, second-, or third-generation EGFR-TKI treatment.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
• Adequate major organ function, defined as: hemoglobin (Hb) ≥ 90 g/L, absolute neutrophil count (ANC) ≥ 1.5 × 10\^9/L, platelet count (PLT) ≥ 100 × 10\^9/L, white blood cell count (WBC) ≥ 3.0 × 10\^9/L and ≤ 10.0 × 10\^9/L; total bilirubin (TBIL) ≤ 1.5 × upper limit of normal (ULN), alanine transaminase (ALT) and aspartate transaminase (AST) ≤ 2.5 × ULN; creatinine clearance ≥ 50 ml/min (for patients with liver metastases, TBIL ≤ 3.0 × ULN, ALT and AST ≤ 5.0 × ULN); activated partial thromboplastin time (APTT), international normalized ratio (INR), and prothrombin time (PT) ≤ 1.5 × ULN.
• At least 21 days since the last radiotherapy (including whole-brain radiotherapy or local radiotherapy for brain metastases).
• Expected survival ≥ 3 months.
• Ability to swallow oral medications (or receive crushed medications via gastrostomy tube if unable to swallow).
• For women: Agreement to use effective contraception (e.g., surgical sterilization or protocol contraception) within 14 days prior to enrollment, during the study, and for 3 months after the last study drug administration.
• For men: Agreement to use effective contraception (e.g., surgical sterilization or protocol contraception) during the study and for 3 months after the last study drug administration.
• Voluntary participation, signed informed consent, and willingness to comply with study procedures and protocols.