The purpose of this research study is to look at how safe and useful a drug called azacitidine in combination with a drug called venetoclax, is in people with accelerated or blast phase BRC-ABL negative myeloproliferative neoplasms.
Ability to voluntarily provide written informed consent.
Documented diagnosis per World Health Organization (WHO) 2016 criteria of BCR-ABL negative myeloproliferative neoplasms (MPN).
Documented MPN transformation to accelerated phase (AP) or blast phase (BP) without prior blast reduction therapy for their AP/BP disease.
Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
History of allogeneic stem cell transplant for MPN.
Previous treatment with venetoclax, navitoclax, azacytidine or other hypomethylating agents (HMA).
White blood cell count >25 x 10^9/L.
Current enrollment in another interventional study.