Analysis of Heterogeneity in Survival Benefit of Immunotherapy in Oncology According to Patient Demographics and Performance Status: A Systematic Review and Meta-Analysis of Overall Survival Data

Objectives:Immunotherapy (IO) has become standard of care (SOC) for many advanced malignancies, although identifying patients likely to benefit remains difficult. We sought to assess whether demographic factors are associated with response to IO, compared with SOC systemic therapy, using stratified meta-Analysis.Methods:A systematic review of MEDLINE, PubMed, Embase, and Scopus from inception to October 2, 2018. Randomized controlled trials comparing IO to SOC in patients with advanced solid organ malignancies were included if results were stratified by age, performance status (PS), or race, assessing overall survival (OS). Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for each group using random-effects models independently.Results:We identified 21 eligible randomized controlled trials, including 20 stratified by age, 17 by PS, and 4 by race. Patients with PS 0 (HR, 0.74; 95% CI, 0.63-0.86) and PS≥1 (HR, 0.75; 95% CI, 0.68-0.83) had similar OS benefits from IO compared with SOC (P=0.80). There was no difference on the basis of patient race (white vs. nonwhite) (P=0.46). IO demonstrated an OS benefit for younger (below 65 y: HR, 0.73; 95% CI, 0.65-0.82) and older (65 y and above: HR, 0.79; 95% CI, 0.71-0.88) patients with no difference between age groups (P=0.27). Among prespecified subgroup analyses, there was significant effect modification in 2 subgroups: younger patients in the first-line setting (P=0.03) and those receiving anti-CTLA-4 drugs (P=0.05).Conclusions:When examining OS using stratified meta-Analysis, we did not demonstrate significant differences in IO efficacy according to patient age, PS or race, though data on race were sparse.