This study is a Phase Ib, open label, multi-center study of to evaluate the safety and efficacy of JMT101 combined with EGFR-TKIs (Afatinib or Osimertinib) in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) harboring EGFR exon 20 insertion mutations.

The objective of the trial is to evaluate the safety and efficacy of JMT101 combined with EGFR-TKIs (afatinib or osimertinib) in patients with locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations.

This study consists of two parts (Stage I and Stage II). Stage I was a dose escalation study, and Stage II was a dose expansion study.

Inclusion Criteria:

• Pathologically or cytologically confirmed, locally advanced or metastatic NSCLC, harboring an EGFR exon 20 insertion mutation. ( non-irradiable, non-operable);
• No previous treatment or first-line treatment failed NSCLC;
• At least 1 measurable lesion according to RECIST 1.1;
• ECOG score 0 or 1;

Exclusion Criteria:

• Previously treated with EGFR antibody;
• Symptomatic brain metastasis;
• Interstitial pneumopathy;
• Known hypersensitivity to any ingredient of JMT101, afatinib, osimertinib or their excipients;
• Receiving an investigational product in another clinical study within 4 weeks;
• History of serious systemic diseases;
• History of serious autoimmune diseases;
• Pregnancy or lactating women.