A prospective, phase II, open-label study (JO22903) of first-line erlotinib in Japanese patients with epidermal growth factor receptor (EGFR) mutation-positive advanced non-small-cell lung cancer (NSCLC)

Abstract Introduction The epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor erlotinib is associated with survival benefits in patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC). This phase II, single-arm study examined the efficacy and safety of first-line erlotinib in Japanese patients with EGFR mutation-positive NSCLC. Methods Eligible patients received erlotinib 150mg/day until disease progression or unacceptable toxicity. The primary endpoints were progression-free survival (PFS) and safety. Results A high degree of concordance was observed between different mutation testing methodologies, suggesting feasibility of early, rapid detection of EGFR mutations. Median PFS was 11.8 months (95% confidence interval [CI]: 9.7–15.3) at data cut-off (1 June 2012) ( n =102). Exon 19 deletions seemed to be associated with longer PFS compared with L858R mutations; T790M mutations were tentatively linked with shorter PFS. The safety profile was as expected: rash (any grade; 83%) and diarrhea (any grade; 81%) were most common. Six interstitial lung disease (ILD)-like cases were reported, and 5 were confirmed as ILD-like events by the extramural committee. Two patients died of treatment-related pneumonitis (JAPIC Clinical Trials Information number: Japic CTI-101085). Conclusion Erlotinib should be considered for first-line treatment in this subset of Japanese patients, with close monitoring for ILD-like events.