...we report the results of the phase II open-label, single-arm, multicenter study investigating the efficacy and safety of Mefatinib as first-line therapy for patients with NSCLC harboring uncommon EGFR mutations (ChiCTR2000029058)….The respective ORR and median progression-free survival (PFS) was 94.1% and 20.6 months for patients with G719X (n = 17), 75.0% and 18.7 months for patients with L861Q (n = 4), and 71.4% and 20.6 months for patients with S768I (n = 7)...our study provides preliminary clinical evidence that first-line Mefatinib therapy was effective, provides durable PFS, and has a manageable toxicity profile in patients with stage IIIB–IV NSCLC harboring EGFR G719X, S768I, and/or L861Q mutations.