Background: TyTAN is a randomized phase III study to evaluate lapatinib (L) plus paclitaxel (P) in pretreated HER2 amplified (HER2+) advanced gastric cancer (AGC). The disease characteristics and GC treatment pattern differed in Japan and in China, so a subgroup analysis was done for subjects recruited in mainland China. Methods: AGC subjects with prior 5-FU and/or cisplatin and HER2 amplification by fluorescence in situ hybridization (FISH) in tumor tissue were randomized 1:1 to L (1500mg QD) and P (80mg/m², Day 1, 8, 15 q4w) or P alone (80mg/m², Day 1, 8, 15 q4w). 1st endpoint was overall survival (OS). 2nd endpoints included progression free survival (PFS), overall response rate (ORR) and safety. A total of 95 subjects recruited from mainland China. Results: TyTAN was not significant in OS (HR0.84), but 2 months OS improvement was observed in L+P arm. The results from Chinese subgroup are shown in the Table. The most common adverse events in Chinese subjects were similar as in whole population (neutropenia, diarrhea, rash, leukopenia, anemia, fatigue). Compare to the overall results, less Chinese subjects reported nausea and vomiting. Conclusions: This analysis showed that there were clear regional differences as observed between subjects in China and Japan. The addition of L to P was associated with a clinically meaningful benefit in subjects recruited from mainland China. These data warrants further prospective evaluations on the impact of regional differences in the outcome of HER+ GC in East Asian patients. Clinical trial information: NCT00486954.