Afatinib versus gemcitabine/cisplatin for first-line treatment of Chinese patients with advanced non-small-cell lung cancer harboring EGFR mutations: Subgroup analysis of the LUX-lung 6 trial

Abstract

Introduction: Non-small-cell lung cancer (NSCLC) is the leading cause of cancer death in China. Four epidermal growth factor receptor (EGFR)-targeted tyrosine kinase inhibitors – afatinib, erlotinib, icotinib, and gefitinib – are available for first-line treatment of NSCLC in China; however, there are few data to guide treatment choice. The Phase III LUX-Lung 6 trial compared afatinib with platinum-based chemotherapy for first-line treatment of patients from Southeast Asia with EGFR mutation-positive advanced NSCLC. This post hoc analysis assessed the findings from LUX-Lung 6 in Chinese patients. Clinical trial registration: ClinicalTrials.gov: NCT01121393. Materials and methods: Previously untreated patients with EGFR mutation-positive stage IIIB/ IV lung adenocarcinoma were randomized 2:1 to receive afatinib or ≤6 cycles of gemcitabine/ cisplatin. The key outcomes were progression-free survival (PFS; primary), objective response rate, disease control rate, overall survival (OS), duration of response and disease control, patient-reported outcomes, and safety. Three hundred and twenty-seven patients from mainland China were treated (89.8% of overall LUX-Lung 6 population; afatinib 217, gemcitabine/cisplatin 110). Results: PFS was significantly longer with afatinib than gemcitabine/cisplatin (median 11.0 versus 5.6 months; hazard ratio [HR], 0.30 [95% CI, 0.21, 0.43]; P<0.0001). Overall, there was no significant difference in OS between treatment arms; however, in a subgroup analysis, afatinib significantly improved OS versus gemcitabine/cisplatin in patients with an EGFR Del19 mutation (median 31.6 versus 16.3 months; HR, 0.61 [95% CI, 0.41, 0.91]; P=0.0146). Afatinib was well tolerated, with most treatment-related adverse events (TRAEs) being of grade 1 or 2 severity. The most common grade 3/4 TRAEs with afatinib were rash/acne (15.9%/0.5%), stomatitis (6.1%/0%), and diarrhea (5.6%/0%). TRAEs leading to permanent discontinuation were reported in 12 patients (5.6%) receiving afatinib and 43 (41.7%) receiving gemcitabine/cisplatin. Afatinib significantly improved PFS compared with standard first-line chemotherapy in Chinese patients with EGFR mutation-positive NSCLC and demonstrated a manageable safety profile. Conclusion: The findings support the rationale for using afatinib as a first-line treatment option for this patient population.