Aim: In the IRESSA Pan-Asia Study (IPASS), 1217 patients in East Asia with pulmonary adenocarcinoma who were never-smokers or ex/light-smokers received first-line gefitinib (250 mg/day) or carboplatin/paclitaxel (area under the curve 5/6; 200 mg/m2). Efficacy analyses were pre-planned in patients in China.
Methods: In China, 372 patients (30.6% of the overall group) were randomized. The primary end-point was progression-free survival (PFS). Secondary end-points were overall survival (OS), objective response rate (ORR), health-related quality of life (HRQoL), symptom improvement, safety and tolerability.
Results: For patients in China, PFS did not significantly differ from the overall IPASS population (interaction test P= 0.427). PFS was numerically longer (hazard ratio [HR] 0.79; 95% CI 0.62–1.01; P= 0.065; median PFS 6.8 months for both treatments) and ORR significantly higher (ORR 44.6 vs 29.8%; odds ratio 1.88; 95% CI 1.22–2.89; P= 0.004) for gefitinib than carboplatin/paclitaxel. OS (mature data) was similar for both treatments (HR 0.92; 95% CI 0.73–1.17; P= 0.511; median OS gefitinib 18.1 months vs 18.3 months carboplatin/paclitaxel). HRQoL improvement rates favored gefitinib; symptom improvement rates were similar for both treatments. Gefitinib had a more favorable tolerability profile than carboplatin/paclitaxel. Efficacy by epidermal growth factor receptor biomarker status (exploratory analyses) was difficult to interpret due to low patient numbers with known biomarker status.
Conclusion: For the Chinese subgroup of IPASS, gefitinib demonstrated improved PFS and ORR, similar OS, higher HRQoL, similar symptom improvement rates and a more favorable tolerability profile than carboplatin/paclitaxel, generally consistent with the overall IPASS population.