Firmonertinib 160 mg in Patients With EGFR-Mutant Advanced NSCLC Demonstrating SD After 8 Week Induction With Firmonertinib 80 mg

Inclusion Criteria: * Age 18-75 years. * ECOG performance status 0-1; life expectancy ≥3 months. * Histologically/cytologically confirmed advanced/metastatic non-squamous NSCLC unsuitable for curative therapy. * Documented EGFR 19del or L858R mutation. * No prior systemic therapy for advanced disease. * Stable disease after 8 weeks of Firmonertinib 80 mg daily. * more than 1 measurable lesion per RECIST v1.1. * Adequate hematologic, renal, hepatic, and coagulation function. * Signed written informed consent. Exclusion Criteria: * Hypersensitivity to Firmonertinib or related compounds. * Other actionable oncogenic drivers (ALK, ROS1, RET, BRAF, NTRK, MET, KRAS, except TP53/RB1). * Prior EGFR-TKI therapy or prohibited concomitant medications. * Unresolved toxicities \>CTCAE Grade 1 (except allowed conditions). * Symptomatic CNS metastases or spinal cord compression. * GI disorders impairing drug absorption. * Uncontrolled systemic diseases or active infections (HBV/HCV/HIV). * Interstitial lung disease (history or active). * Clinically significant cardiac abnormalities including QTc \>470 ms or LVEF \<50%. * Pregnancy or breastfeeding. * Any condition compromising compliance. * CR, PR, or PD at completion of induction therapy.