PATIENTS AND METHODS: Patients with EGFR-mutated advanced NSCLC who progressed after osimertinib and platinum-based chemotherapy were randomly assigned 1:1 to receive subcutaneous or intravenous amivantamab, both combined with lazertinib. Coprimary pharmacokinetic noninferiority end points were trough concentrations (Ctrough; on cycle-2-day-1 or cycle-4-day-1) and cycle-2 area under the curve (AUCD1-D15). Key secondary end points were objective response rate (ORR) and progression-free survival (PFS). Overall survival (OS) was a predefined exploratory end point.

RESULTS: Overall, 418 patients underwent random assignment (subcutaneous group, n = 206; intravenous group, n = 212). Geometric mean ratios of Ctrough for subcutaneous to intravenous amivantamab were 1.15 (90% CI, 1.04 to 1.26) at cycle-2-day-1 and 1.42 (90% CI, 1.27 to 1.61) at cycle-4-day-1; the cycle-2 AUCD1-D15 was 1.03 (90% CI, 0.98 to 1.09). ORR was 30% in the subcutaneous and 33% in the intravenous group; median PFS was 6.1 and 4.3 months, respectively. OS was significantly longer in the subcutaneous versus intravenous group (hazard ratio for death, 0.62; 95% CI, 0.42 to 0.92; nominal P = .02). Fewer patients in the subcutaneous group experienced infusion-related reactions (IRRs; 13% v 66%) and venous thromboembolism (9% v 14%) versus the intravenous group. Median administration time for the first infusion was reduced to 4.8 minutes (range, 0-18) for subcutaneous amivantamab and to 5 hours (range, 0.2-9.9) for intravenous amivantamab. During cycle-1-day-1, 85% and 52% of patients in the subcutaneous and intravenous groups, respectively, considered treatment convenient; the end-of-treatment rates were 85% and 35%, 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.