Gefitinib With Concurrent Thoracic Radiotherapy in Unresectable Locally Advanced NSCLC With EGFR Mutation; West Japan Oncology Group 6911L

Introduction: About 10% of patients with locally advanced NSCLC (LA-NSCLC) harbor EGFR mutation and recent reports suggested the declined benefit with an immune checkpoint inhibitor in this population. The attempt that introduces EGFR tyrosine kinase inhibitor into the treatment of LA-NSCLC with EGFR mutation has been warranted.

Methods: Chemotherapy-naive patients with unresectable LA-NSCLC with sensitive EGFR mutation (exon 19 deletion or exon 21 L858R point mutation) were enrolled. Patients were treated with gefitinib (250 mg/d for 2 y) plus concurrent thoracic radiotherapy (64 Gy/32 fractions). The primary end point was progression-free survival (PFS) at 2 years (trial identifier, UMIN000008366).

Results: Between August 2012 and November 2017, a total of 28 patients were enrolled and 27 were eligible. The median age was 67 years (range: 45-74); never/current or former smoker in 15/12 patients, respectively; Eastern Cooperative Oncology Group performance status of 0/1 in 19/8; EGFR exon 19 deletion/exon 21 L858R in 13/14; and c-stage IIIA/IIIB in 14/13. The PFS rate at 2 years by independent review was 29.6% (one-sided 95% confidence interval [CI]: 17.6%-). The overall response rate was 81.5% (95% CI: 63.3%-91.3%), median PFS was 18.6 months (95% CI: 12.0-24.5 mo), and median overall survival was 61.1 months (95% CI: 38.1 mo-not reached). Approximately half of the patients exhibited solitary brain metastasis as their first site of relapse. Adverse events greater than or equal to grade 3 were fatigue, skin reaction, and appetite loss (3.7% each).

Conclusions: This prospective study revealed the tolerability and the possible efficacy of gefitinib plus concurrent thoracic radiotherapy in patients with LA-NSCLC having EGFR mutation.