Anti-PD-1 therapy for clinical treatment of lymphoma: a single-arm meta-analysis

Anti-PD1 antibodies exhibit satisfactory efficacy in treating certain types of lymphoma. We conducted this meta-analysis to explore subtypes benefiting from this treatment and the best anti-PD1 therapeutic modalities. METHODS: A quantitative meta-analysis was performed via a systematic search in PubMed, Web of Science, and The Cochrane Library. The pooled overall response rate (ORR), progression-free survival (PFS), complete remission rate (CRR), overall survival (OS) and adverse events (AEs) were calculated and compared. Data were analyzed using a random-effects meta-analysis to determine risk ratios. Heterogeneity across studies was analyzed using Q and I(2) statistics. RESULTS: Thirteen articles were selected, and 9 studies were included in the meta-analysis. There was evidence of significant heterogeneity among the studies. According to PD-L1 expression subgroup analysis, the PD-L1-positive group exhibited significantly better outcomes than the PD-L1-negative group (Z=5.481, p=0.000), with pooled ORRs of 0.74 (95% CI: 0.67–0.81) and 0.2 (95% CI: 0.11–0.3), respectively. For PD-L1-positive and PD-L1-negative patients, the pooled CRRs, PFS and OS were 0.21 (95% CI: 0.14–0.29), 0.76 (95% CI: 0.71–0.81) and 1.0 (95% CI: 0.98–1.0) and 0.05 (95% CI: 0.01–0.11), 0.20 (95% CI: 0.09–0.39) and 0.64 (95% CI: 0.45–0.80), respectively; differences were all statistically significant (Z=2.248, p=0.025; Z=3.555, p=0.000; and Z=3.039, p=0.002, respectively). The pooled incidence of treatment-related all-grade AEs and grade-3/4 AEs was 0.84 (95% CI: 0.75–0.92) and 0.21 (95% CI: 0.15–0.29), respectively. CONCLUSION: Patients with PD-L1 overexpression in relapsed or refractory lymphoma benefited more from anti-PD-1 therapy. Moreover, treatment with approved PD-1 inhibitors was well tolerated.