Venetoclax-azacitidine as salvage therapy for relapsed mixed phenotype acute leukemia after a second allogeneic hematopoietic stem cell transplantation: a case report.

TO THE EDITOR: Mixed phenotype acute leukemia (MPAL) is rare, accounting for approximately 1–4% of acute leukemia (AL) cases [1]. Induction therapy for these cases is often based on acute lymphocytic leukemia (ALL) treatment protocols, followed by allogeneic stem cell transplantation (ASCT). However, post-ASCT relapse after ASCT remains the primary cause of treatment failure. The median overall survival (OS) of patients who relapse after ASCT is extremely poor, with a median 3-year survival rate ranging between 9% and 11% [2]. Recent studies have reported better survival rates with a combination of venetoclax (VEN) and hypomethylating agents (HMA). Here, we describe the case of a 36-year-old patient with B/T MPAL who developed medullary relapse after 2 ASCTs and was successfully treated with VEN and azacitidine (VEN-AZA).