Efficacy and safety of maintenance erlotinib in Asian patients with advanced non-small-cell lung cancer: a subanalysis of the phase III, randomized SATURN study

Maintenance therapy, commenced immediately after the completion of first-line chemotherapy, is a promising strategy for improving treatment outcomes in patients with non-small-cell lung cancer (NSCLC). The global phase III SequentiAl Tarceva in UnResectable NSCLC (SATURN) study evaluated the efficacy and safety of the epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor erlotinib as maintenance treatment in NSCLC patients without progression after first-line chemotherapy. We report a retrospective subanalysis of Asian patients enrolled in SATURN. Patients with advanced NSCLC with no evidence of progression after four cycles of chemotherapy were randomized to receive erlotinib 150 mg/day or placebo, until progressive disease or limiting toxicity. The co-primary endpoints of SATURN were progression-free survival (PFS) in all patients and in those with positive EGFR immunohistochemistry (IHC) status. Secondary endpoints included overall survival (OS), disease control rate, safety, quality of life (QoL) and biomarker analyses. In total, 126 patients from East and South-East Asian centers were randomized (14% of the intent-to-treat population): 88 from Korea, 28 from China and 10 from Malaysia; one patient was excluded from this analysis due to Indian ethnicity. PFS was significantly prolonged in the erlotinib treatment arm, both overall (hazard ratio [HR]: 0.57; p=0.0067) and in patients with EGFR IHC-positive disease (HR=0.50; p=0.0057). There was a trend towards an increase in OS, which reached statistical significance in the EGFR IHC-positive subgroup (p=0.0233). The overall response rate was significantly higher with erlotinib compared with placebo (24% versus 5%; p=0.0025). Erlotinib was generally well tolerated and had no negative impact on QoL in this subpopulation. The most common treatment-related adverse events were rash, diarrhea and pruritus. Erlotinib was effective and well tolerated in Asian patients, producing benefits consistent with those observed in the overall SATURN population. Maintenance treatment with erlotinib appears to be a useful option for the management of Asian patients with advanced NSCLC without progression after first-line chemotherapy.