The efficacy of PD-1 inhibitors in the maintenance treatment of diffuse large B-cell lymphoma: A single-center retrospective analysis

To explore the impact of PD-1 maintenance therapy on the relapse-free survival (RFS) of patients with diffuse large B-cell lymphoma (DLBCL).We retrospectively analyzed patients with DLBCL admitted to our center between January 2018 and July 2019 who achieved complete remission (CR) after induction chemotherapy. Forty-five patients who received PD-1 inhibitor maintenance therapy were considered the treatment group. Forty-five patients who did not undergo maintenance treatment during the same period were selected as the control group. The base levels of the two groups of patients were similar. The 2-year RFS rate of the two groups was compared. The correlation between the adverse prognosis factors of the patients and the RFS rate was performed subgroup analysis.The 2-year RFS rates of the treatment and control groups were 86.7% VS 75.6% (P = 0.178), respectively, until July 2021. A single factor analysis showed that patients with International Prognostic Index (IPI) score ≥ 3, non-GCB DLBCL receiving PD-1 inhibitor maintenance treatment, can improve their 2-year RFS (72.2% VS 30.8%, P = 0.022; 88.5% VS 62.5%, P = 0.032). For non-GCB patients, the 2-year RFS of the treatment group can reach 88.5%, while the 2-year RFS of the control group is 62.5%, which is statistically significant (P = 0.032). In all patients treated with PD-1 inhibitors, the adverse reactions were all grade I-II, and there were no grade III-IV adverse reactions. There were no clear adverse events in the follow-up patients in the control group.Maintenance treatment with PD-1 inhibitors can improve the 2-year RFS rate of patients with IPI score of ≥3 and non-GCB DLBCL. This prompts the potential advantage of PD-1 inhibitors in DLBCL maintenance treatment. However, longer follow-ups remain needed to obtain more definite data.