A Phase II Trial on Osimertinib as a First-Line Treatment for EGFR Mutation-Positive Advanced NSCLC in Elderly...

Osimertinib is one of the standard first-line treatments for advanced non-small cell lung cancer in patients with epidermal growth factor receptor (EGFR) mutations, because it achieves significantly longer progression-free survival (PFS) than conventional first-line treatments (hazard ratio: 0.46). However, the efficacy and safety of osimertinib as a first-line treatment for patients aged ≥75 years remain unclear.

This phase II study was performed to prospectively investigate the efficacy and safety of osimertinib for elderly patients with EGFR mutation-positive advanced non-small cell lung cancer. The primary endpoint was 1-year PFS rate; secondary endpoints were overall response rate (ORR), PFS, overall survival (OS), and safety.

Thirty-eight patients were included in the analysis. The 1-year PFS rate was 59.4% (95% confidence interval [CI], 46.1%-72.7%), which did not meet the primary endpoint (the threshold 1-year PFS rate of 50% predicted using data from the NEJ003 study). The most common grade 3/4 adverse events were rash/dermatitis acneiform/ALT increased/hypokalemia (2 patients, 5%). Seven patients developed pneumonitis (17.5%). There were no other cases of treatment discontinuation due to adverse events other than pneumonitis.

Although this study did not meet the primary endpoint, osimertinib was tolerable for elderly patients with EGFR mutation-positive advanced non-small cell lung cancer. (Japan Registry of Clinical Trials [JRCT] ID number: jRCTs071180007).