The meta-analysis showed that XAPI adjunctive to platinum-based chemotherapy had better outcomes in objective tumor response rate (ORR) (RR: 1.27, 95% CI, 1.14–1.40); improved Karnofsky performance scores (KPS) (RR: 1.70, 95% CI, 1.48–1.95); reduction in occurrence of grade 3/4 leukopenia (RR: 0.49, 95% CI, 0.38–0.64), anemia (RR: 0.63, 95% CI, 0.46–0.87) and thrombocytopenia (RR: 0.53, 95% CI, 0.38–0.73), nausea and vomiting (RR: 0.57, 95% CI, 0.36–0.90); and enhanced immune function (CD8+ [MD: 4.96, 95% CI, 1.16–8.76] and CD4+/CD8+ [MD: 2.58, 95% CI, 1.69–3.47]). The gene discussed is CD4; the disease is neoplasm.