Age

18–75

Sex

ALL

Healthy volunteers

Not accepted

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.

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.

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