PL03.05: BRAIN: A Phase III Trial Comparing WBI and Chemotherapy with Icotinib in NSCLC with Brain Metastases Harboring EGFR Mutations (CTONG 1201)

Abstract

Non-small cell lung cancer (NSCLC) with brain metastases (M) had a poor prognosis. Whole brain irradiation (WBI) is a standard of care for this critical medical condition. The median survival is only 4-6 months. Small molecule inhibitors of epidermal growth factor receptor (EGFR) including icotinib achieved very successful results in advanced NSCLC with EGFR mutations. There were no prospective randomized clinical trials to explore the efficacy of EGFR tyrosine kinase inhibitors (TKIs) on brain M. Advanced NSCLC with EGFR sensitive mutations and brain M were randomized to WBI plus chemotherapy (chemo) or icotinib. Patients in WBI arm received radiotherapy with 30Gy/3Gy/10 fractions plus concurrent or sequential doublet chemo of 4-6 cycles. Patients in EGFR TKI arm received icotinib 125mg orally tid until disease progression. Icotinib could be continued beyond progression if clinical benefit was observed by the investigator. Crossover to icotinib from WBI could be permitted. Key inclusion criteria were EGFR mutations and radiologically confirmed brain M with at least 3 lesions. The primary endpoint was intracranial progression-free survival (iPFS) by investigator assessments according to RECIST v1.1. The secondary endpoints included objective response rate (ORR), PFS and overall survival (OS). Safety and tolerability were assessed by measuring adverse events (AEs)(CTCAE v4). From Dec. 2012 to June 2015, 176 patients from 17 sites were randomized to WBI+Chemo arm (N=91) or icotinib arm (N=85). The baseline clinicopathologic factors were balanced between the two groups. Median age was 58, PS 1 was 87.2%, non-smoker 70.9%, adenocarcinoma 96.8%, symptomatic brain M were 16.5%. Icotinib significantly improved median iPFS compared with WBI+chemo: hazard ratio [HR] 0.56; 95% CI: 0.36-0.90; p=0.014 (10.0 vs 4.8 months). Median PFS was 6.8 vs 3.4 months, (HR 0.44, 95% CI 0.31-0.63, P<0.001). Median OS had no significant difference between the arms (18.0 vs 20.5 months, HR 0.93, 95%CI 0.60-1.44, P=0.734). Intracranial ORR was significantly improved with icotinib than WBI+Chemo (67.1% vs 40.9%; p<0.001); Overall ORR was 55.0% vs 11.1% (P<0.001). Grade ≥3 AEs assessed by the investigators were reported in 8.2% (N=7) of patients treated with icotinib and 26.2% (N=28) treated with WBI+Chemo. Most common causally related AEs in the icotinib arm were increased liver transaminase & rash; in the WBI+Chemo arm were hematologic toxicity. Icotinib demonstrated superior iPFS, PFS and ORR over WBI+Chemo in EGFR mutant advanced NSCLC with brain M, and well-tolerated safety profile. Icotinib would be a treatment option for EGFR mutant patients with brain M (NCT01724801).