Abstract: Objective:To systematically evaluate the clinical efficacy of programmed death-1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors versus traditional first-line regimens for the treatment of solid tumors.
Methods:Databases including PubMed, Embase and Cochrane Library were searched for literatures from the date of their establishment to October 2018 with the key words including “PD-1/PD-L1, solid tumors, melanoma, non-small cell lung cancer, renal cell carcinoma, immunotherapy”. The randomized controlled trial or non randomized controlled trial of high quality about PD-1/PD-L1 inhibitors and traditional fist-line regimens for the treatment of solid tumors were received and enrolled. Patients underwent PD-1/PD-L1 inhibitors immunotherapy were allocated into treatment group, patients underwent traditional first-line regimens treatment were allocated into control group. Two reviewers independently screened literatures, extracted data and assessed the risk of bias. Count data were described as odds ratio (OR) and 95% confidence interval (95%CI). The heterogeneity of the studies included was analyzed using the I2 test. Funnel plot was used to test potential publication bias if the studies included≥5, and no test was needed if the studies included<5.
Results:(1) Document retrieval: a total of 11 available randomized clinical trials were included. There were 5 161 patients, including 2 677 in the treatment group and 2 484 in the control group. (2) Results of Meta analysis. ① There was a significant difference in the objective response rate between the treatment group and the control group (OR=4.49, 95%CI: 3.01-6.68, P<0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ② There was no significant difference in the disease control rate between the treatment group and the control group (OR=1.53, 95%CI: 1.01-2.32, P=0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ③ There was a significant difference in disease stability rate between the treatment group and the control group (OR=0.49, 95%CI: 0.33-0.73, P<0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ④ There was no significant difference in disease progression rate between the treatment group and the
control group (OR=0.71, 95%CI: 0.45-1.15, P>0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies, suggesting that publication bias had little influence on results of Meta analysis. ⑤ There were significant differences in overall incidence of adverse events and incidence of adverse events not less than three levels between the treatment group and the control group (OR=0.53, 0.54, 95%CI: 0.38-0.74, 0.31-0.93, P<0.05). The bilateral symmetry was presented in the funnel plot based on the 11 studies, suggesting that publication bias had little influence on results of Meta analysis.
Conclusion:Compared with traditional first-line regimens treatment, PD-1/PD-L1 inhibitors immunotherapy can improve the objective response rate and decrease the incidence of adverse events.