Safety and efficacy of first-line dacomitinib in Asian patients with EGFR mutation-positive non-small cell lung cancer: Results from a randomized, open-label, phase 3 trial (ARCHER 1050)

To compare efficacy and safety of dacomitinib versus gefitinib as first-line therapy for EGFR mutation-positive advanced NSCLC in Asian patients enrolled in the ongoing ARCHER 1050 trial.In this ongoing, randomized, open-label, phase 3 trial (NCT01774721), eligible patients with newly diagnosed advanced EGFR mutation-positive NSCLC were randomized (1:1) to receive oral dacomitinib 45 mg/day or oral gefitinib 250 mg/day. Randomization, by a central computer system, was stratified by race and EGFR mutation type (exon 19 deletion mutation/exon 21 L858R substitution mutation). The primary endpoint was PFS by blinded independent review.Of 346 Asian patients, 170 were randomized to dacomitinib and 176 to gefitinib. The hazard ratio (HR) for PFS with dacomitinib versus gefitinib was 0.509 (95 % confidence interval [CI]: 0.391-0.662; 1-sided p < 0.0001; median 16.5 months [95 % CI: 12.9-18.4] vs. 9.3 months [95 % CI: 9.2-11.0]). HR for OS with dacomitinib versus gefitinib was 0.759 (95 % CI: 0.578-0.996; median 37.7 months [95 % CI: 30.2-44.7] vs. 29.1 months [95 % CI: 25.6-36.0]). The OS benefit was still maintained in those patients who had a stepwise dose reduction of dacomitinib (to 30 and 15 mg/day). The most common adverse events (AEs) were diarrhea (154 [90.6 %] patients), paronychia (110 [64.7 %]), dermatitis acneiform (96 [56.5 %]), and stomatitis (87 [51.2 %]) with dacomitinib, and diarrhea (100 [56.8 %]), alanine aminotransferase increased (81 [46.0 %]), and aspartate aminotransferase increased (75 [42.6 %]) with gefitinib. Treatment-related serious AEs were reported in 16 (9.4 %) and 8 (4.5 %) patients treated with dacomitinib and gefitinib, respectively.First-line dacomitinib was associated with significant prolongation of PFS and improved OS compared with gefitinib in Asian patients with EGFR mutation-positive advanced NSCLC. The AE profiles of dacomitinib and gefitinib in Asian patients were consistent with the overall ARCHER 1050 population.