Clinical outcomes and safety of tislelizumab maintenance therapy following autologous stem cell transplantation in patients with relapsed or refractory diffuse large b-cell lymphoma

Abstract Objective: Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin lymphoma, and patients with relapsed/refractory (R/R) disease who fail standard first-line therapy generally have a poor prognosis. High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (ASCT) can be used as salvage therapy for relapsed or refractory DLBCL; however, the necessity and optimal regimen for post-ASCT maintenance therapy remain unclear. This study aimed to evaluate the clinical efficacy and safety of tislelizumab maintenance therapy after ASCT in patients with relapsed or refractory DLBCL (NCT04799314). Methods:This is a multicenter, randomized controlled, prospective clinical trial. A total of 150 patients with R/R DLBCL were planned for enrollment. Eligible patients were aged 18–65 years, histologically confirmed DLBCL, and achieved complete response or partial response after second- or later-line chemotherapy. Patients were randomized 1:1 to receive tislelizumab (200 mg every 42 days, IV) for eight cycles post-ASCT hematopoietic recovery or no intervention (control). The primary endpoint was 2-year progression-free survival (PFS) rate, and secondary endpoints included 2-year overall survival (OS) rate and safety. Results:From February 2021 to March 2025, 60 patients were randomized to receive tislelizumab (n=30) and no intervention (n=30). All 60 enrolled patients were included in the analysis. All patients received similar conditioning regimens and achieved hematopoietic recovery after ASCT. The median follow-up was 34.2 months (range: 3.6–53.4 months). The 2-year PFS rate was 94.4% (95% CI: 66.6%–99.2%) in the tislelizumab versus 72.2% (95% CI: 51.9%–85.0%) in the control group (p=0.012). The 2-year OS rate was 100.0% (95% CI: 100.0%–100.0%) in the tislelizumab group compared to 83.7% (95% CI: 61.7%–93.6%) in the control group (p=0.062). One patient in tislelizumab group (3.3%) experienced grade 3 alanine aminotransferase elevation, with no other adverse events reported. No treatment discontinuations or dose reductions occurred. Conclusion:Maintenance therapy with tislelizumab after ASCT improves progression-free survival in patients with R/R DLBCL and demonstrates a favorable safety profile.