A Study Evaluating the Efficacy and Safety of Pemetrexed Combined With Platinum-Based Chemotherapy Followed by Befotertinib in Patients With Non-Small Cell Lung Cancer After Third-Generation EGFR TKI Resistance
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;
• Life expectancy of at least 12 weeks;
• Ability to swallow oral medications;
• Adequate organ system function, defined as follows and determined based on investigator judgment:
∙ Absolute neutrophil count (ANC) ≥ 1.5 x 10⁹/L
‣ Platelets ≥ 100 x 10⁹/L;
‣ Hemoglobin ≥ 9 g/dL (≥ 90 g/L). Note: Blood transfusions are permitted to achieve the required hemoglobin level;
‣ Total bilirubin ≤ 1.5 times the upper limit of normal (ULN);
‣ If no liver metastases: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN; if liver metastases present: ≤ 5 × ULN;
‣ Creatinine ≤1.5 × ULN. If ≥1.5 × ULN, patients remain eligible if the Cockcroft-Gault-calculated creatinine clearance ≥50 mL/min (0.83 mL/s);
• Female subjects of childbearing potential must have a negative serum pregnancy test within 3 days prior to study drug initiation and agree to use a medically approved highly effective contraceptive method (e.g., intrauterine device, oral contraceptives, or condoms) during the study and for 3 months after the last study drug administration; Male subjects with female partners of childbearing potential must be surgically sterilized or agree to use an effective method of contraception during the study period and for 3 months after the last study dose.
• Voluntarily agree and be capable of adhering to the trial and follow-up procedures.
⁃ Be able to understand the nature of the trial and complete the written informed consent form.