PB2330 EFFICACY OF MAINTENANCE THERAPY AFTER AUTOLOGOUS HEMATOPOIETIC STEM CELL TRANSPLANTATION IN HIGH‐RISK AGGRESSIVE LYMPHOMA: A SINGLE‐CENTER NON‐RANDOMIZED STUDY

Abstract

Background:Autologous hematopoietic stem cell transplantation is the main treatment for lymphoma. While relapse after autologous hematopoietic stem cell transplantation (ASCT) is still challenging for high‐risk aggressive lymphoma.Aims:This study was to investigate the efficacy and safety of maintenance therapy post‐ASCT.Methods:From June 2009 to December 2018, patients with high‐risk aggressive lymphoma in our hospital were treated with maintenance therapy post‐ASCT according to the patient's needs and wishes, and then assigned to maintenance group or observation group. The end point of follow‐up was disease progression or death. The 4‐year overall survival (OS) and disease‐free survival (DFS) were compared between these two groups.Results:A total of 92 patients were enrolled, apart from 2 cases of early death, the remaining 90 patients underwent ASCTsuccessfully and achieved CR post‐ASCT. 59 patients were assigned to the observation group, and 31 patients to the maintenance group, including 22 with rituximab regimen,7 with DPP/DCEP‐G alternation regimen, and 2 with Chidamideregimen. There were no significant differences in gender, age,diagnosis,IPI score,pre‐transplant disease status, and hematopoietic reconstitution between the two groups. The main causes of death were disease recurrence. No serious adverse reactions occurred during the maintenance treatment period. After a median follow‐up of 616 days (12‐2854 days), and the DFS of the 1st, 2nd,3rd and 4thyears were67.1% VS 95.2%, 51.1% VS 90.5%, 48.1% VS 90.5%, 43.8% VS 90.5% (P = 0.002), respectively. The OS of the 1st, 2nd, 3rd and 4thyears were 90.0% VS 100%, 84.4% VS 95.2%, 77.3% VS 95.2%, 73.3% VS 95.2% (P = 0.126), respectively.For the overall survival rate, single factor analysis showed age <30 years old, LDH increased before ASCTwere prognostic factors affecting OS; COX multi‐factor regression analysis showed age <30 years old, LDH increased before ASCTwere independent prognostic factors for OS. The risk of death in patients <30 years of age was 4.376 times higher than that in patients aged 30 years or older (P = 0.026, HR = 4.376, 95% CI = 1.188‐16.116). The risk of death in patients with LDH increased before ASCT was 5.165 times higher than in patients with normal LDH before ASCT (P = 0.015, HR = 5.165, 95% CI = 1.375‐19.395).For the disease‐free survival rate, single factor analysis showed that the initial admission to LDH increased, LDH increased before ASCT, IPI score≥2 points, maintenance treatment after ASCT were prognostic factors for DFS; COX multi‐factorregression Analysis showed that LDH increased before ASCTand maintenance treatment after ASCT were independent prognostic factors for DFS. The risk of recurrence of patients with LDH increased before ASCT was 2.648 times higher than that of normal LDH patients before ASCT (P = 0.034, HR = 2.648, 95% CI = 1.078‐6.507), and the risk of recurrence in maintenance‐treated patients after ASCT was 0.130 times than that in patients without maintenance therapy after ASCT (P = 0.006, HR = 0.130, 95% CI = 0.031‐0.557).Conclusion: Maintenance therapy post‐ASCT could reduce the risk of relapse and promote disease‐free survival, which deserves further investigation.Summary/Conclusion:Maintenance therapy post‐ASCT could reduce the risk of relapse and promote disease‐free survival, which deserves further investigation.image