Abstract
BACKGROUND: With the advent of asparaginase-based drugs, patients with natural killer/T-cell lymphoma (NKTCL) have achieved excellent efficacy. However, the prognosis is poor in patients with advanced disease, and even worse in relapse/refractory patients. This meta-analysis aimed to evaluate the efficacy and safety of PD-1/PD-L1 inhibitor monotherapy or combination treatment strategies in patients with NKTCL. METHOD: Seven databases were extensively searched from inception to November 2023 and updated in April 2024, with no language restrictions. The pooled overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and treatment-related adverse events (AEs) were calculated via a random effects model. Heterogeneity was tested utilizing the I-square (I(2)) test and Cochrane's Q test. Subgroup analysis was used to compare the effects of single PD-1/PD-L1 inhibitors or combination treatment in NKTCL patients. RESULTS: A total of thirteen single-arm studies involving 460 patients were enrolled. The results revealed that the pooled ORR was 62% (95% CI: 48-76%). In terms of survival outcomes, the pooled 1-year OS was 67% (95% CI: 47-87%) and the 2-year OS was 47% (95% CI: 24-69%). Moreover, the 1-year and 2-year PFS rates were 66% (95% CI: 48-84%) and 59% (95% CI: 34-84%), respectively. With regard to treatment toxicity, the pooled incidence of all-grade AEs was 86% (95% CI: 79-93%), and the pooled incidence of grade 3 or higher AEs was 29% (95% CI: 22-36%). Leukopenia and hypoalbuminemia were identified as the most common hematologic and non-hematologic adverse events, respectively. CONCLUSION: Evidence suggests that PD-1/PD-L1 inhibitors are promising treatment options for newly diagnosed NKTCL patients. PD-1/PD-L1 inhibitors combined with chemotherapy or chidamide has demonstrated superior clinical efficacy in patients with relapsed/refractory NKTCL. TRIAL REGISTERATION: Open Science Framwork: osf.io/2bwh3.