Chidamide-Based Pre-Emptive Treatment for High-Risk AML Patients after Hematopoietic Stem Cell Transplantation: A Real-World Experience from Chinese Single-Center

• Published in: Blood 2023-11, Vol.142 (Supplement 1), p.2890-2890
• Main Authors: Wu, Ping, Ling, Wei, Luo, Chengwei, Chen, Xiaomei, Huang, Lisi, Wang, Jinghua, Lai, Peilong, Wu, Suijing, Du, Xin, Weng, Jianyu
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2023-187924

Background: The treatment of relapsed or refractory acute myeloid leukemia ( AML) remains challenging. Measurable residual disease (MRD) persistence at transplantation or post-transplantation has been identified as the strongest risk factor for relapse and poor outcomes for patients with hematological malignancies (HMs). Chidamide, a novel oral histone deacetylase inhibitor, has shown potential therapeutic effects in various types of HMs by inducing cell apoptosis and regulating immunity. This study aimed to evaluate the efficacy and safety of Chidamide-based prophylactic or pre-emptive treatment for patients who are MRD positive before or who have sustained MRD positive after transplantation. Aim: The rate of 6 months of conversion to MRD- and relapse-free survival of high-risk AML after Chidamide-based treatment. Methods: From December 2020 to July 2023, 50 patients with high-risk HMs received chidamide-based therapy after allo-HSCT. 39 patients were diagnosed with AML ( 4 secondary AML), 2 with myelodysplastic syndromes, 6 with acute lymphoid leukemia, and 3 with mixed-phenotype acute leukemia. 46 patients (92%) with relapsed/refractory status or detectable MRD (MRD+) at transplantation or after allo-HSCT received chidamide as pre-emptive, and the remaining 4 high-risk patients with MRD− conducted as prophylactic intervention. Patients with detectable MRD before transplantation and those who remained positive for MRD after transplantation were defined as very high-risk AML (VHR-AML). Chidamide was administered at a dose of 5 mg per day orally, 6 times per week, lasting at least 1 year after engraftment. Additional agents included hypomethylating agents (HMAs), donor lymphocyte infusion (DLI) or tyrosine kinase inhibitor (TKI) in patients with Philadelphia chromosome-positive. In this study, 28 patients received chidamide monotherapy, 13 received chidamide combined with HMAs, and 9 cases with other therapy. Results: The median age of all patients was 38 years old (range 17-67), comprising 24 males and 26 females. Up to 1st July 2023, with a median follow-up period of 376 days (25-984d), the overall rate of MRD negative showed 64%. The rate of MRD- survival, Relapse-free survival (RFS) and overall survival (OS) were 56%, 66% and 76%, respectively. The 6 months MRD negative rate, RFS and OS rate were 86%, 82%, 86% and 88%, which maintained at 82%, 82% and 86% with 12 months follow-up, respectively. In 46 cases of the pre-emptive intervention arm, the overa