Comparison of anti-PD-1/PD-L1-based regimens in relapsed/refractory diffuse large B-cell lymphoma: a meta-analysis

To evaluate the therapeutic value and find out potential combination agents of programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) monoclonal antibody (mAb) in relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL).

We conducted a meta-analysis to assess the efficacy and safety of PD-1/PD-L1 mAb in r/r DLBCL, potential qualified studies were searched in PubMed, Embase, Web of Science, and ClinicalTrials.gov. This meta-analysis had been registered on the PROSPERO platform (CRD42023340031).

After systematic screening, a total of 32 records involving 29 studies were included, pooled survival curves indicated better progression-free survival (PFS) (p < 0.0001; HR = 0.51, 95% CI [0.42-0.62]) and overall survival (OS) (p = 0.013; HR = 0.71, 95% CI [0.57-0.88]) for combination therapy compared with monotherapy. Combination therapy group also achieved a better pooled complete response rate (CRR) (14.6% vs. 3.0%; p < 0.001) and overall response rate (ORR) (30.5% vs. 10.3%; p < 0.001). Analysis of the incidence of adverse events (AEs) did not demonstrate additional toxicities of combination therapy. The limitation was the predominance of single-arm trials, precluding the direct comparison of combination versus partner agents alone.

These findings support further exploration of PD-1/PD-L1-mAb-based combination therapy to identify long-term survival benefits, while application of monotherapy in unselected DLBCL patients is not recommended.