A Phase II Study of First-line Afatinib For Patients Aged ≥ 75 Years With EGFR Mutation-positive Advanced Non-small Cell Lung Cancer: North East Japan Study Group Trial NEJ027

Background: We investigated afatinib in elderly patients with epidermal growth factor receptor (EGFR) mutation-positive advanced non-small cell lung cancer (NSCLC).Patients and Methods: This was a single-arm, open-label, phase II study, performed in multiple centres in Japan. Previously untreated patients, aged ≥ 75 years, with EGFR mutation-positive (Del19 or L858R) advanced NSCLC were treated with afatinib 40 mg until disease progression or unacceptable toxicity. Adverse events (AEs) were managed with protocol defined dose adjustments. The primary endpoint was objective response rate (ORR) by central review.Results: In total, 38 patients received at least one dose of afatinib, and 37 were evaluable for response. Median age was 77.5 years (range 75–91), all patients had an Eastern Cooperative Oncology group performance status of 0 or 1, and 60.5% had Del19-positive disease. ORR was 75.7% (2 complete responses and 26 partial responses). Median progression-free survival was 14.2 months (95% confidence interval [CI], 9.5–19.0). Median overall survival (OS) was 35.2 months (95% CI, 35.2–not reached); the 2-year OS rate was 78.3%. The most common grade III/IV treatment-related AEs (TRAEs) were diarrhoea (28.9%), paronychia (23.7%), and rash/acne (15.8%). Dose reductions due to TRAEs were reported in 78.9% of patients, and 8 (21.1%) patients discontinued afatinib due to TRAEs. No treatment-related deaths were reported.Conclusion: First-line afatinib administered at a starting dose of 40 mg was well tolerated with dose adjustments and was associated with encouraging activity in Japanese patients aged ≥ 75 years with EGFR mutation-positive NSCLC.Trial Registration: The trial is registered with Japan Registry of Clinical Trials (JRCT) as trial number 031180136 (date of initial registration: 19 February 2019), and the University Hospital Network (UMIN) as trial number 000017877 (date of initial registration: 11 June 2015).