METHODS: Eligible Asian patients (enrolled at Asian sites) who were at least 18 years of age (≥20 years in Japan) and had untreated EGFR-mutated advanced NSCLC were randomized 1:1 to receive osimertinib (80 mg, orally once daily) or an SoC EGFR TKI (gefitinib, 250 mg, or erlotinib, 150 mg, orally once daily). The primary end point was investigator-assessed progression-free survival (PFS). The key secondary end points were overall survival, objective response rate, central nervous system efficacy, and safety.

RESULTS: The median PFS was 16.5 versus 11.0 months for the osimertinib and SoC EGFR TKI groups, respectively (hazard ratio = 0.54, 95% confidence interval: 0.41-0.72, p < 0.0001). The overall survival data were immature (24% maturity). The objective response rates were 80% for osimertinib and 75% for an SoC EGFR TKI. The median central nervous system PFS was not calculable for the osimertinib group and was 13.8 months for the SoC EGFR TKI group (hazard ratio = 0.55, 95% confidence interval: 0.25-1.17, p = 0.118). Fewer adverse events of grade 3 or higher (40% versus 48%) and fewer adverse events leading to treatment discontinuation (15% versus 21%) were reported with osimertinib versus with an SoC EGFR TKI, respectively.

METHODS: In this double-blind, phase 3 trial, we randomly assigned 556 patients with previously untreated, EGFR mutation-positive (exon 19 deletion or L858R) advanced NSCLC in a 1:1 ratio to receive either osimertinib (at a dose of 80 mg once daily) or a standard EGFR-TKI (gefitinib at a dose of 250 mg once daily or erlotinib at a dose of 150 mg once daily). The primary end point was investigator-assessed progression-free survival.

RESULTS: The median progression-free survival was significantly longer with osimertinib than with standard EGFR-TKIs (18.9 months vs. 10.2 months; hazard ratio for disease progression or death, 0.46; 95% confidence interval [CI], 0.37 to 0.57; P<0.001). The objective response rate was similar in the two groups: 80% with osimertinib and 76% with standard EGFR-TKIs (odds ratio, 1.27; 95% CI, 0.85 to 1.90; P=0.24). The median duration of response was 17.2 months (95% CI, 13.8 to 22.0) with osimertinib versus 8.5 months (95% CI, 7.3 to 9.8) with standard EGFR-TKIs. Data on overall survival were immature at the interim analysis (25% maturity). The survival rate at 18 months was 83% (95% CI, 78 to 87) with osimertinib and 71% (95% CI, 65 to 76) with standard EGFR-TKIs (hazard ratio for death, 0.63; 95% CI, 0.45 to 0.88; P=0.007 [nonsignificant in the interim analysis]). Adverse events of grade 3 or higher were less frequent with osimertinib than with standard EGFR-TKIs (34% vs. 45%).