Previous results from this phase 3 trial showed that progression-free survival among participants with previously untreated (epidermal growth factor receptor)-mutated advanced non-small-cell lung cancer (NSCLC) was significantly improved with amivantamab-lazertinib as compared with osimertinib. Results of the protocol-specified final overall survival analysis in this trial have not been reported.

We randomly assigned, in a 2:2:1 ratio, participants with previously untreated -mutated (exon 19 deletion or L858R substitution), locally advanced or metastatic NSCLC to receive amivantamab-lazertinib, osimertinib, or lazertinib. Overall survival (assessed in an analysis of the time from randomization to death from any cause) in the amivantamab-lazertinib group as compared with the osimertinib group was a key secondary end point. Additional end points included safety.

A total of 429 participants each were assigned to receive amivantamab-lazertinib or osimertinib. Over a median follow-up of 37.8 months, amivantamab-lazertinib led to significantly longer overall survival than osimertinib (hazard ratio for death, 0.75; 95% confidence interval, 0.61 to 0.92; P = 0.005); 3-year overall survival was 60% and 51%, respectively. At the clinical cutoff date, 38% of participants in the amivantamab-lazertinib group and 28% in the osimertinib group were still receiving the assigned treatment. Adverse events of grade 3 or higher were more common with amivantamab-lazertinib (in 80% of participants) than with osimertinib (in 52%), particularly skin-related events, venous thromboembolism, and infusion-related events; these findings were consistent with the established safety profile of each treatment. No new safety signals were observed with additional follow-up.

Amivantamab-lazertinib led to significantly longer overall survival among participants with previously untreated -mutated advanced NSCLC than osimertinib but was associated with an increased risk of adverse events of grade 3 or higher. (Funded by Janssen Research and Development; MARIPOSA ClinicalTrials.gov number, NCT04487080.).