Japanese subgroup analysis of a phase III study of S-1 versus docetaxel in non-small cell lung cancer patients after platinum-based treatment: EAST-LC.

Introduction: The East Asia S-1 Trial in Lung Cancer (EAST-LC) was a randomized phase III study conducted in East Asia that demonstrated the non-inferiority of S-1 to docetaxel in previously treated patients with advanced non-small cell lung cancer (NSCLC). Here, we reported the results of the Japanese subgroup treated with docetaxel 60 mg/m, the standard dosage in Japan.

Patients And Methods: Patients were randomized 1:1 to receive either S-1 or docetaxel. The primary endpoint was overall survival (OS); the secondary endpoints included progression-free survival (PFS), response rate (RR), quality of life (QOL), and safety.

Results: Patient characteristics in the Japanese subgroup (n = 724) were similar to those in the overall EAST-LC population. Median OS was 13.4 months in the S-1 group and 12.6 months in the docetaxel group. In pemetrexed-pretreated patients, OS with S-1 was similar to that with docetaxel. Median PFS was 2.9 and 3.0 months in the S-1 and docetaxel groups, respectively. RR was 9.4% and 10.3% in the S-1 and docetaxel groups, respectively. The QOL of patients treated with S-1 was better compared with that of patients treated with docetaxel. Decreased appetite and diarrhea were more common in the S-1 group, whereas the frequency of neutropenia and febrile neutropenia was markedly higher in the docetaxel group.

Conclusions: This Japanese subgroup analysis showed that S-1 had similar efficacy to docetaxel in patients with previously treated advanced NSCLC. These results are similar to those of the overall EAST-LC population.