Chidamide combined with azacitidine as a novel double epigenetic preemptive treatment for a myelodysplastic syndrome patient showing molecular relapse after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is theoretically the only curative option for high-risk myelodysplastic syndrome (HR MDS) patients. However, the management of patients with relapsed disease post allo-HSCT remains a challenge with few standard treatments. Chidamide, a new selective histone deacetylase, has shown synergistic anti-leukemia effect combined with azacitidine in acute myeloid leukemia patients. Herein, we reported a 50-year-old HR MDS patient who experienced molecular relapse post allo-HSCT and was successfully salvaged by preemptive treatment of chidamide combined with azacitidine (CHI-AZA). This patient maintained a deep remission lasting over 2 years by regular maintenance treatment of CHI-AZA, without sever treatment-related adverse events or increased risk of graft versus host disease. This case report demonstrated that double epigenetic regimen of CHI-AZA was effective and tolerable. Formally evaluating this regimen in HR MDS patients post allo-HSCT may be meaningful.