Afatinib in EGFR TKI-naïve patients (pts) with locally advanced/metastatic NSCLC harbouring EGFR mutations: An interim analysis of a phase IIIB trial

Abstract

Background: First-line afatinib significantly improved progression-free survival (PFS) in pts with EGFR mutation-positive (EGFRm+) NSCLC (including uncommon mutations) vs chemotherapy (CT) in the LUX-Lung (LL) 3/6 trials (median 11.1 vs 6.9 mos; HR 0.58/11.0 vs 5.6 mos; HR 0.28) and vs gefitinib in LL7 (median 11.0 vs 10.9 mos; HR 0.73). However, in real-world (RW) practice CT remains a first-line choice. Here, we report an interim analysis of a Phase IIIb study of afatinib in treatment-naive or CT pre-treated pts with EGFRm+ NSCLC, similar to RWpractice. Method(s): EGFR TKI-naive pts with locally advanced/metastatic EGFRm+ NSCLC and ECOG PS 0-2 received 40 mg/day afatinib (starting dose). Dose reduction was permitted (to minimum 20 mg/day). Primary endpoint: adverse events (AEs) in a descriptive fashion. Efficacy was also assessed. Result(s): At data cut-off (30 April 2018), 479 pts were enrolled and treated with afatinib (Caucasian/Asian/other: 97%/2%/<1%; male/female: 34%/66%; 1st/2nd/ >= 3rd-line therapy: 78%/17%/5%; ECOG PS 0/1/2: 36%/57%/8%; brain metastases: 17%; common/ uncommon mutations: 87%/13%). Median time on afatinib was 359 days. The most common grade >= 3 afatinib-related AEs were diarrhoea (16%) and rash (11%). AEs led to dose reduction in 258 (54%) pts (most frequently diarrhoea 25%; rash 11%) and to afatinib discontinuation in 105 (22%) pts (most frequently diarrhoea 3% [rash 0.8%]). Afatinib-related serious AEs occurred in 39 (8%) pts. Time to symptomatic progression (TTSP) and PFS are shown in the table. Objective response rate and disease control rate were 46% and 86%, respectively. Conclusion(s): Interim analysis of this study, which included pts treated with afatinib in later lines, and pts with ECOGPS 2, brain metastases and/or uncommon mutations, indicates a predictable and manageable safety profile for afatinib, consistent with the pivotal LL trials. Interim efficacy findings are encouraging, with a median TTSP of 14.9months.