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 a phase 3, international, randomized trial, we assigned, in a 2:2:1 ratio, patients with previously untreated EGFR-mutated (exon 19 deletion or L858R), locally advanced or metastatic NSCLC to receive amivantamab-lazertinib (in an open-label fashion), osimertinib (in a blinded fashion), or lazertinib (in a blinded fashion, to assess the contribution of treatment components). The primary end point was progression-free survival in the amivantamab-lazertinib group as compared with the osimertinib group, as assessed by blinded independent central review.

RESULTS: Overall, 1074 patients underwent randomization (429 to amivantamab-lazertinib, 429 to osimertinib, and 216 to lazertinib). The median progression-free survival was significantly longer in the amivantamab-lazertinib group than in the osimertinib group (23.7 vs. 16.6 months; hazard ratio for disease progression or death, 0.70; 95% confidence interval [CI], 0.58 to 0.85; P<0.001). An objective response was observed in 86% of the patients (95% CI, 83 to 89) in the amivantamab-lazertinib group and in 85% of those (95% CI, 81 to 88) in the osimertinib group; among patients with a confirmed response (336 in the amivantamab-lazertinib group and 314 in the osimertinib group), the median response duration was 25.8 months (95% CI, 20.1 to could not be estimated) and 16.8 months (95% CI, 14.8 to 18.5), respectively. In a planned interim overall survival analysis of amivantamab-lazertinib as compared with osimertinib, the hazard ratio for death was 0.80 (95% CI, 0.61 to 1.05). Predominant adverse events were EGFR-related toxic effects. The incidence of discontinuation of all agents due to treatment-related adverse events was 10% with amivantamab-lazertinib and 3% with osimertinib.

EXPERIMENTAL DESIGN: Tumor tissue EGFRm status was determined at screening using the central cobas tissue test or a local tissue test. Baseline circulating tumor (ct)DNA EGFRm status was retrospectively determined with the central cobas plasma test.

RESULTS: Of 994 patients screened, 556 were randomized (289 and 267 with central and local EGFR test results, respectively) and 438 failed screening. Of those randomized from local EGFR test results, 217 patients had available central test results; 211/217 (97%) were retrospectively confirmed EGFRm positive by central cobas tissue test. Using reference central cobas tissue test results, positive percent agreements with cobas plasma test results for Ex19del and L858R detection were 79% [95% confidence interval (CI), 74-84] and 68% (95% CI, 61-75), respectively. Progression-free survival (PFS) superiority with osimertinib over comparator EGFR-TKI remained consistent irrespective of randomization route (central/local EGFRm-positive tissue test). In both treatment arms, PFS was prolonged in plasma ctDNA EGFRm-negative (23.5 and 15.0 months) versus -positive patients (15.2 and 9.7 months).