APR-246 Combined with Azacitidine (AZA) in TP53Mutated Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML). a Phase 2 Study By the Groupe Francophone Des Myélodysplasies (GFM)

Introduction: TP53mutated (TP53m) MDS and AML have very poor outcome irrespective of the treatment received, including 40% responses (20% CR) with azacitidine (AZA) with short response duration and a median overall survival (OS) of about 8 months (Bejar, Blood 2014). APR-246 is a prodrug spontaneously converted to methylene quinuclidinone (MQ), a Michael acceptor that binds covalently to cysteines in mutant p53, leading to protein reconformation that reactivates its pro apoptotic and cell cycle arrest functions. The combination of AZA and APR 246 showed promising results in a phase Ib study in TP53mMDS (Sallman, ASH 2018). We report interim results of a GFM phase 2 study of AZA+ APR-246 in TP53mMDS and AML, conducted in parallel with a similar US MDS consortium study.