Updated survival outcomes of NEJ005/TCOG0902, a randomized PII of gefitinib and chemotherapy in EGFR-mutant NSCLC

Abstract

Background: North East Japan Study Group (NEJ) 005/ Tokyo Cooperative Oncology Group (TCOG) 0902 study has demonstrated that first‐line concurrent (C) and sequential alternating (S) combination therapies of EGFR tyrosine kinase inhibitor (gefitinib) plus platinum‐based doublet chemotherapy (carboplatin/pemetrexed) offer promising efficacy with predictable toxicities for patients with EGFR‐mutant NSCLC (ASCO2014, Ann Oncol 2015). However, overall survival (OS) data were insufficient because of the lack of death events in the primary report. Method: Progression‐free survival (PFS) and OS were re‐evaluated at the final data cutoff point (March 2017) for the entire population (N = 80). Result: At the median follow‐up time of 35.6 months, 88.8% of patients had progressive disease and 77.5% of patients had died. Median PFS was 17.5 months for the C regimen and 15.3 months for the S regimen (p = 0.13). Median OS time was 41.9 with the C regimen and 30.7 months with the S regimen (p = 0.036). Updated response rates were similar in both groups (90.2% and 82.1%, respectively; p = 0.34). Patients who had common mutations showed no significant differences in PFS according to type of mutation. Patients with Del19 displayed relatively better OS (median: 45.3 and 33.3 months for C and S regimens) than those with L858R (31.4 and 28.9 months). No severe adverse events including interstitial lung disease have occurred during the follow‐up period since the primary report. In an exploratory analysis, there was no significant difference in post progression survival and overall survival between patients with progression of target or nontarget lesions and those progressed with new lesions. Conclusion: This updated analysis has confirmed that PFS is improved with firstline combination therapies compared to that with gefitinib monotherapy, and the C regimen in particular offers an overall survival benefit of 42 months in the EGFR‐mutated setting. Our on‐going NEJ009 study will clarify whether this combinational strategy can be incorporated into routine clinical practice.