Abstract: Objective To investigate the impact of PD-1 inhibitors maintenance therapy on prognosis of diffuse large B-cell lymphoma(DLBCL) patients. Methods The DLBCL patients who achieved complete response(CR) after induction chemotherapy admitted to our center from March 2018 to March 2019 were retrospectively analyzed. Among them, the therapy group received PD-1 inhibitors maintenance therapy(30 cases), and 30 patients who did not receive maintenance therapy during the same period were selected as the control group. The relapse-free survival(RFS) rate of the two groups were compared, and the efficacy and safety of PD-1 inhibitors maintenance therapy were observed. Results Follow-up until March 2021, the 2-year RFS rates of the therapy group and the control group were 80.0% and 73.3%(P=0.542), respectively. Subgroup analysis showed that the patients with international prognostic index(IPI) score ≥ 3points (70% vs 22.2%, P=0.037), non-GCB type(90.9% vs 45.5%, P=0.022) received PD-1 inhibitors maintenance treatment had a significant benefit in 2-year RFS rates compared with the control group. The main adverse reactions in the therapy group were controllable, all of grade Ⅰ-Ⅱ, including rash(2 cases), leukopenia(5 cases), hypothyroidism(3 cases) , liver damage(1 cases), thrombocytopenia(1 cases), abnormal glucose and lipid metabolism(1 cases) , digestive tract reaction(1 cases). Conclusions The maintenance treatment with PD-1 inhibitors cannot significantly improve the RFS of patients with DLBCL, but it has a potential advantages in patients with IPI score ≥ 3points and non-GCB DLBCL.

Key words: PD-1 inhibitors, Diffuse large B-cell lymphoma, Maintenance therapy, Relapse-free survival, Prognostic factors