• This meta-analysis demonstrated that for patients with advanced EGFR-mutant lung cancer first-line EGFR TKIs prolong PFS overall and in all subgroups analyzed compared to chemotherapy, but the relative benefit was greatest in patients with EGFR exon 19 deletion mutations.

This meta-analysis of 7 trials is consistent with other data sets showing better outcomes with EGFR TKIs among patients with EGFR deletion 19 mutations than in those with exon 21 L858R substitution mutations. Of interest, little difference in benefit was observed based on factors such as age, performance status, tumor histology and ethnicity. OS data are considered immature and currently demonstrate no benefit.

Clinical investigators are quick to point out that although patients with L858R mutations derive relatively less benefit than those with EGFR exon 19 deletion mutations, they nonetheless have better outcomes with TKI treatment than with chemotherapy. However, indirect comparisons suggest greater benefit with chemotherapy for patients with less common mutations, such as exon 20 insertions, and in those situations EGFR TKIs are either not used or are employed much later in the sequence of therapies.