P3.13-22 Real World Study of Afatinib in First-Line or Re-Challenge Setting for Patients with EGFR Mutant Non-Small Cell Lung Cancer.

Abstract

Afatinib is the second generation epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitor (TKI) for mutant non-small cell lung cancer (NSCLC), and approved in Japan in 2014. This study evaluated clinical outcomes of afatinib in real world practice. Patients who received afatinib for advanced EGFR-mutant NSCLC in 5 institutions in Aomori, Japan from October 2014 to January 2017 were included into the analyses. In total, 128 patients were analyzed. Seventy-six patients received afatinib as first-line setting and 52 as re-challenge setting (i.e., prior first generation TKIs used and third generation TKI were not adapted). In first-line setting, patient characteristics were as follows: a median age 68 yrs (42- 88 yrs), 67% female, and 88.1% PS 0/1. The median progression-free survival (PFS) was 17.8 months (95% CI: 13.7- 21.5 months). The overall survival (OS) was 39.5 months (95% CI: 34.4- not reached). There was no difference in median PFS and OS according to age (< 74, 75 ≦). Though 58 patients (76.3%) had to reduce the dose due to adverse events, it did not affect its efficacy in terms of OS (39.5 months in the reduction group vs. not yet reached in the no reduction group) (P= 0.37). Moreover, the reduction group showed even longer PFS than the no reduction group. (18.0 months in the no reduction group vs. 7.9 months in the reduction group) (P= 0.016). The response rate (RR) was 64% (CR/PR/SD/PD/NE: 1/48/16/1/10). Twenty-eight patients among 48 who had PD underwent re-biopsy, and 16 patients (57.1%) were T790M positive. In re-challenge setting, patient characteristics were as follows: a median age 65 yrs (37- 90 yrs), 78% female, and 90.3% PS 0/1. The median PFS was 8.0 months (95% CI: 4.9- 9.5 months). The RR was 24% (CR/PR/SD/PD/NE: 1/12/29/6/4). Most common adverse events leading to dose modification and treatment discontinuation were diarrhea, paronychia, and oral mucositis in both settings. Interstitial lung disease occurred in 5.4% (7/128). In the real practice in Japan, afatinib in first-line and re-challenge settings showed comparable or better efficacy compared with previous clinical trials.