Non-small cell lung cancer (NSCLC) accounts for over 85% of lung cancers. Approximately 30-40% of East Asian adenocarcinoma patients harbor EGFR mutations. Third-generation EGFR-TKIs achieve a median PFS of about 20 months as first-line therapy, but resistance eventually develops. Studies like MARIPOSA-2 confirm that amivantamab combined with chemotherapy ± lazertinib or immunotherapy regimens (ivucitinib/sintilimab + bevacizumab + chemotherapy) can extend median PFS post-resistance from approximately 4 months to 6-8 months. As a third-generation TKI, befitinib has demonstrated PFS of 16-22 months in both first-line and post-T790M mutation settings. This study aims to further evaluate the feasibility and safety of "pemetrexed + carboplatin followed by befotertinib" for patients resistant to third-generation TKIs.
Age ≥18 years;
Histologically or cytologically confirmed advanced or metastatic non-squamous NSCLC; and prior resistance to third-generation EGFR TKIs, with EGFR-sensitive mutations confirmed via tissue or blood samples (defined as: 19 Del or 21 L858R);
Exclusion of small cell lung cancer (SCLC) or squamous cell carcinoma (SqCC) transformation, and known NSCLC with clear targetable mutations for targeted therapy, such as HER2, MET amplification (GCN ≥ 5), KRAS G12C mutation, BRAF V600E mutation, RET fusion mutation, ALK fusion mutation, NTRK fusion mutation, etc.;
ECOG performance status (PS) score of 0-2;
Rare EGFR mutations;
Prior treatment with pemetrexed and platinum-based chemotherapy regimens;
Advanced and/or symptomatic brain metastases (measurable or non-measurable) and/or leptomeningeal metastases;
Active hepatitis B (serum HBV DNA ≥10⁴ copies/mL [i.e., 20,000 IU/mL]), hepatitis C virus antibody positive, HIV antibody positive, or treponema pallidum antibody positive;