A meta-analysis comparing responses of Asian versus non-Asian cancer patients to PD-1 and PD-L1 inhibitor-based therapy

Background Subgroup analysis of clinical trials of PD-1/PD-L1 inhibitors have reported ethnic differences in outcomes. We systematically collected published data and performed a meta-analysis to compare therapeutic efficacy in Asian and non-Asian patients receiving PD-1/PD-L1 inhibitors. Methods Eligible studies included phase II and III prospective clinical trials with available subgroup data on Asian versus non-Asian populations. Overall survival (OS) and progression-free survival (PFS) were used to evaluate differences in outcome between Asian versus non-Asian cancer patients. Results A total of 11,020 cancer patients from 19 prospective randomized controlled clinical trials were included. The overall estimated HR for OS was 0.69 with 95% CI of 0.61-0.77 in Asian versus 0.82 with 95% CI of 0.77-0.88 in non-Asian patients. The estimated hazard ratio (HR) for PFS measured 0.54 (95% CI, 0.32-0.76) and 0.69 (95% CI, 0.54-0.85) in Asian and non-Asian patients, respectively. Pooled ratios of OS HRs and PFS HRs reported in Asian versus non-Asian cancer patients were 0.84 (95% CI, 0.75-0.94) and 0.78 (95% CI, 0.59-0.97), respectively. Conclusions This meta-analysis shows for the first time that Asian cancer patients have a significantly improved survival benefit than non-Asian patients receiving PD-1/PD-L1 inhibitor-based therapy.