Osimertinib or Platinum/Pemetrexed in EGFR T790M–Positive Lung Cancer
Results from the phase III AURA3 trial of osimertinib* vs chemotherapy were reported in The New England Journal of Medicine a little more than 1 year after U.S. Food and Drug Administration (FDA) approval of the drug. Tony S. Mok, MD, of the Chinese University of Hong Kong, and colleagues reported that osimertinib* significantly improved progression-free survival vs platinum/pemetrexed among patients with EGFR T790M–positive NSCLC progressing during first-line EGFR tyrosine kinase inhibitor therapy.
The primary endpoint in this study was investigator-assessed progression-free survival. One-third of patients had central nervous system metastases.
Median progression-free survival in the osimertinib group was 10.1 months vs 4.4 months in the platinum/pemetrexed group. Objective response rates were 71% vs 31%, respectively. Maintenance pemetrexed was permitted along with osimertinib, and crossover was allowed from the chemotherapy arm to osimertinib after objective disease progression.
In addition to T790M, EGFR mutations included exon 19 deletion and exon 21 L858R. More than 400 patients were enrolled in the trial from 126 sites between August 2014 and September 2015. Subjects had previously been treated with EGFR TKIs, including gefitinib, erlotinib, and afatinib, and had progressive disease.
*Osimertinib was approved for second-line NSCLC by the US FDA in late 2015, potentially contingent on confirmatory studies. This is the publication of results on which this approval was based.