This is a phase II study aimed to assess the efficacy and safety of firmonertinib combined with carboplatin/cisplatin and pemetrexed as neoadjuvant therapy in stage II-IIIB resectable NSCLC patients.

In this open-label, single-arm, phase 2 study, 31 eligible patients with EGFR mutated stage IIIA-IIIB resectable NSCLC will be recruited to receive firmonertinib for 12 weeks combined with carboplatin/cisplatin and pemetrexed for 4 cycles (21 d/cycle) as neoadjuvant therapy before radical surgery. Radiological and pathological evaluations will be performed before and after the neoadjuvant therapy to assess the efficacy of treatment. Adverse events during neoadjuvant therapy, disease and survival status will also be collected in the study.

Inclusion Criteria:

1. Provide informed consent prior to any study specific procedures
2. at least 18 years of age
3. Histology or cytology diagnose of non-small cell lung cancer within 60 days
4. ECOG PS of 0 to 1 at screening with no clinically significant deterioration in the previous 2 weeks
5. Stage II-IIIB NSCLC that is expected to be resectable, as assessed by the investigator (8 thUICCTNM staging),
6. According to RECIST 1.1, patients have at least one measureable tumor lesion (The longest axis ≥10mm)
7. EGFR mutation positive (exon 19 deletions or exon 21 L858R, with or without other EGFR mutations)
8. Without prior anti-tumor treatment
9. Withe adequate organ function of hematology, liver and kidney
10. Using adequate and effective contraception, Male patients should be use condoms; women should refrain from breastfeeding and have a negative pregnancy test prior to the first administration of the study drug if within during child-bearing age

Exclusion Criteria:

1. Dual or multiple primary NSCLC
2. Any prior anti-tumor treatment
3. With history of other malignancy except for radical resected tumors without recurrence for 5 years or more
4. Diseases or clinical states with severe abnormalities of gastrointestinal function that may interfere with the ingestion, transit, or absorption of the study drug.e.g., inability to take medication orally, uncontrolled nausea and vomiting
5. With severe or uncontrolled systemic disease such as uncontrolled hypertention, diabetes mellitus, chronic heart failure, unstable angina, myocardial infarction within 1 year, active hemorrhage, active HBV/HCV/HIV or other infections requiring infusion treatment
6. Laboratory tests indicate insufficient bone marrow reserve or organ reserve
7. Women with pregnancy or breastfeeding
8. Patients with known or suspected drug allergies, or other contraindications
9. Other conditions that, in the opinion of the investigator, make participation in this trial inappropriate
10. Patients who are currently or previously enrolled in any other anti-tumor clinical study.