Afatinib In The Treatment Of Advanced Nsclc With Egfr Mutation: An Observational Real-World Study.

e20518 Background: Compared with the first generation of EGFR-TKI, Afatinib has a broader spectrum of activity and can better inhibit tumor growth. At present, the therapeutic effects of Afatinib varies on patients with different EGFR mutations and studies on the mechanism of acquired Afatinib resistance are limited. The aim of this study was to evaluate the efficacy and safety of Afatinib in the treatment of EGFR-mutation NSCLC who hadn’t received EGFR-TKI in the past. Methods: 88 patients with advanced NSCLC who had EGFR mutations were enrolled and given oral 40 mg Afatinib daily until disease progression or adverse events that could not be handled by dosage reduction. Efficacy and safety in different subgroups were analyzed. Results: Among 88 patients, the common mutation rate of EGFR was 79.5%, and the rare mutation rate was 20.5%. The objective remission rate (ORR) was 54.5%, and the disease control rate (DCR) was 92.0%. The median progression-free survival (PFS) was 14.2 months (95% CI 11.4-18.5), 27 patients (30.7%) continued Afatinib treatment after tumor progression, and the median time to progression of clinical symptoms (TTSP) was 16.3 months (95% CI 12.7-19.3). A total of 13 patients (14.8%) reduced Afatinib dosage of due to adverse events. Subgroup analysis showed that Afatinib had better effect on patients harboring common EGFR mutation but not exon 20 mutation, and was not affected by brain metastasis, dosage and lines of therapy. Among patients who progressed on Afatinib, 65.4% harbored T790M mutation. Most T790M patients received the third generation EGFR-TKI including AZD9291 and oxetinib treatment. The most common adverse reactions were diarrhea, rash, paronychia and stomatitis. Conclusions: Afatinib showed good efficacy and tolerance in advanced NSCLC patients with EGFR mutations. Continuation of Afatinib treatment after cancer progression could delay the progression of disease symptoms. The third generation EGFR-TKI could become a treatment option after Afatinib resistance. These findings reflected the real-world clinical practice of Afatinib.