An East Asian subgroup analysis of PROCLAIM, a phase III trial of pemetrexed and cisplatin or etoposide and cisplatin plus thoracic radiation therapy followed by consolidation chemotherapy in locally advanced nonsquamous non-small cell lung cancer.

Aim: PROCLAIM, a phase III trial of patients with nonsquamous non-small cell lung cancer comparing concurrent pemetrexed-cisplatin and thoracic radiation therapy followed by consolidation pemetrexed, did not meet its primary endpoint of superior overall survival versus etoposide-cisplatin and thoracic radiation therapy followed by a consolidation platinum doublet of choice. The results from an East Asian subgroup analysis are presented here. Methods: A subgroup analysis was performed for all patients randomized from China (n = 61), Taiwan (n = 25), and Korea (n = 11). Results: Baseline characteristics were balanced between treatment arms for East Asian patients. In the 97 randomized East Asian patients, median overall survival was 26.8 months for the pemetrexed-cisplatin arm and 36.3 months for the etoposide-cisplatin arm (hazard ratio: 1.23; 95% confidence interval: 0.70-2.14; P = 0.469). Median progression-free survival was 10.0 months for the pemetrexed-cisplatin arm and 7.6 months for the etoposide-cisplatin arm (hazard ratio: 0.97; 95% confidence interval: 0.61-1.54; P = 0.890). The objective response rate was 47.7% in the pemetrexed-cisplatin arm and 34.0% in the etoposide-cisplatin arm (P = 0.167). In the 90 treated East Asian patients, the overall incidence of drug-related grade 3-4 treatment-emergent adverse events was significantly lower in the pemetrexed-cisplatin arm versus the etoposide-cisplatin arm (61.4% vs 91.3%; P = 0.001). Conclusion: For East Asian patients, pemetrexed-cisplatin combined with thoracic radiation therapy, followed by consolidation pemetrexed, did not improve overall survival but did have a good safety profile with a trend for improved progression-free survival and objective response rate compared to standard chemoradiotherapy for stage III unresectable nonsquamous non-small cell lung cancer.