Venetoclax and Azacitidine for the Treatment of High-Risk Recurrent or Refractory Myelodysplastic Syndrome

PRIMARY OBJECTIVE: I. To determine the safety and tolerability (phase 1) and overall response rate (ORR) (phase 2) of venetoclax in combination with azacitidine in patients with treatment-naive high-risk myelodysplastic syndrome (MDS) or chronic myelomonocytic leukemia (CMML) with bone marrow excess blasts \> 5% and patients that are relapsed/refractory to prior hypomethylating agent (HMA) therapy. SECONDARY OBJECTIVES: I. Rate of complete remission (CR). II. Rate of marrow/morphologic complete remission (mCR). III. Rate of hematologic improvement (HI; erythroid/platelet/neutrophil responses). IV. Rate of red blood cell (RBC) transfusion independence. V. Rate of platelet (PLT) transfusion independence. VI. Rate of cytogenetic response. VII. Rate of bone marrow blast response. VIII. Time to transformation to acute myeloid leukemia (AML). IX. Duration of response (DOR). X. Overall survival (OS). XI. Progression-free survival (PFS). XII. Time to next MDS treatment (TTNT). XIII. Event-free survival (EFS). EXPLORATORY OBJECTIVE: I. To investigate the effects of therapy on MDS and to identify biological markers of response to venetoclax and/or its combination with azacitidine. OUTLINE: This is a phase I, dose-escalation study of venetoclax followed by a phase II study. Patients receive venetoclax orally (PO) once daily (QD) on days 1-7 or 1-14 and azacitidine subcutaneously (SC) or intravenously (IV) over 15 minutes on days 1-5. Cycles repeat every 4-8 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days and then every 3-6 months for up to 5 years.