Chun‐Ming Tsai

PURPOSE: The LUX-Lung 3 study investigated the efficacy of chemotherapy compared with afatinib, a selective, orally bioavailable ErbB family blocker that irreversibly blocks signaling from epidermal growth factor receptor (EGFR/ErbB1), human epidermal growth factor receptor 2 (HER2/ErbB2), and ErbB4 and has wide-spectrum preclinical activity against EGFR mutations. A phase II study of afatinib in EGFR mutation-positive lung adenocarcinoma demonstrated high response rates and progression-free survival (PFS). PATIENTS AND METHODS: In this phase III study, eligible patients with stage IIIB/IV lung adenocarcinoma were screened for EGFR mutations. Mutation-positive patients were stratified by mutation type (exon 19 deletion, L858R, or other) and race (Asian or non-Asian) before two-to-one random assignment to 40 mg afatinib per day or up to six cycles of cisplatin plus pemetrexed chemotherapy at standard doses every 21 days. The primary end point was PFS by independent review. Secondary end points included tumor response, overall survival, adverse events, and patient-reported outcomes (PROs). RESULTS: A total of 1,269 patients were screened, and 345 were randomly assigned to treatment. Median PFS was 11.1 months for afatinib and 6.9 months for chemotherapy (hazard ratio [HR], 0.58; 95% CI, 0.43 to 0.78; P = .001). Median PFS among those with exon 19 deletions and L858R EGFR mutations (n = 308) was 13.6 months for afatinib and 6.9 months for chemotherapy (HR, 0.47; 95% CI, 0.34 to 0.65; P = .001). The most common treatment-related adverse events were diarrhea, rash/acne, and stomatitis for afatinib and nausea, fatigue, and decreased appetite for chemotherapy. PROs favored afatinib, with better control of cough, dyspnea, and pain. CONCLUSION: Afatinib is associated with prolongation of PFS when compared with standard doublet chemotherapy in patients with advanced lung adenocarcinoma and EGFR mutations.

INTRODUCTION: PIONEER (NCT01185314) was a prospective, multinational, epidemiological study of epidermal growth factor receptor (EGFR) mutations in patients from Asia with newly diagnosed advanced lung adenocarcinoma. METHODS: Eligible patients (aged ≥20 years) had untreated stage IIIB/IV adenocarcinoma. The EGFR mutation status (primary end point: positive, negative, or undetermined) of tumor samples (biopsy, surgical specimen, or cytology) was determined (Scorpion amplification refractory mutation system). EGFR mutation frequency was calculated and compared between demographic and clinical subgroups. RESULTS: Of 1482 patients from seven Asian regions, 43.4% of patients were female, median age was 60 years (range, 17-94), and 52.6% of patients were never-smokers. EGFR mutation status was evaluable in tumors from 1450 patients (97.8%) (746 [51.4%] positive; 704 [48.6%] negative). Country, sex, ethnicity, smoking status, pack-years (all p < 0.001), disease stage (p = 0.009), and histology type (p = 0.016) correlated significantly with EGFR mutation frequency. Mutation frequency was 61.1% in females, 44.0% in males; lower in patients from India (22.2%) compared with other areas (47.2%-64.2%); highest among never-smokers (60.7%); and decreased as pack-year number increased (>0-10 pack-years, 57.9%; >50 pack-years, 31.4%) (similar trend by sex). Ethnic group (p < 0.001) and pack-years (p < 0.001) had statistically significant associations with mutation frequency (multivariate analysis); sex was not significant when adjusted for smoking status. CONCLUSION: PIONEER is the first prospective study to confirm high EGFR mutation frequency (51.4% overall) in tumors from Asian patients with adenocarcinoma. The observed high mutation frequency in demographic/clinical subgroups compared with white populations suggests that mutation testing should be considered for all patients with stage IIIB/IV adenocarcinoma, even males and regular smokers, among Asian populations.

BACKGROUND: The epidermal growth factor receptor (EGFR) signaling pathway is crucial for regulating tumorigenesis and cell survival and may be important in the development and progression of non-small cell lung cancer (NSCLC). We examined the impact of EGFR-tyrosine kinase inhibitors (TKIs) on progression-free survival (PFS) and overall survival (OS) in advanced NSCLC patients with and without EGFR mutations. METHODS: Randomized trials that compared EGFR-TKIs monotherapy or combination EGFR-TKIs-chemotherapy with chemotherapy or placebo were included. We used published hazard ratios (HRs), if available, or derived treatment estimates from other survival data. Pooled estimates of treatment efficacy of EGFR-TKIs for the EGFR mutation-positive (EGFRmut(+)) and EGFR mutation-negative (EGFRmut(-)) subgroups were calculated with the fixed-effects inverse variance weighted method. All statistical tests were two-sided. RESULTS: We included 23 eligible trials (13 front-line, 7 second-line, 3 maintenance; n = 14570). EGFR mutation status was known in 31% of patients. EGFR-TKIs treatment prolonged PFS in EGFRmut(+) patients, and EGFR mutation was predictive of PFS in all settings: The front-line hazard ratio for EGFRmut(+) was 0.43 (95% confidence interval [CI] = 0.38 to 0.49; P < .001), and the front-line hazard ratio for EGFRmut(-) was 1.06 (95% CI = 0.94 to 1.19; P = .35; P interaction < .001). The second-line hazard ratio for EGFRmut(+) was 0.34 (95% CI = 0.20 to 0.60; P < .001), and the second-line hazard ratio for EGFRmut(-) was 1.23 (95% CI = 1.05 to 1.46; P = .01; P interaction < .001). The maintenance hazard ratio for EGFRmut(+) was 0.15 (95% CI = 0.08 to 0.27; P < .001), and the maintenance hazard ratio for EGFRmut(-) was 0.81 (95% CI = 0.68 to 0.97; P = .02; P interaction < .001). EGFR-TKIs treatment had no impact on OS for EGFRmut(+) and EGFRmut(-) patients. CONCLUSIONS: EGFR-TKIs therapy statistically significantly delays disease progression in EGFRmut(+) patients but has no demonstrable impact on OS. EGFR mutation is a predictive biomarker of PFS benefit with EGFR-TKIs treatment in all settings. These findings support EGFR mutation assessment before initiation of treatment. EGFR-TKIs should be considered as front-line therapy in EGFRmut(+) advanced NSCLC patients.