Background: The growth factor receptor bound protein-2 (Grb2) is vital to oncogene signaling and tumor progression. BP1001 is a liposome-incorporated Grb2 antisense oligonucleotide that inhibits Grb2 expression. Grb2 inhibition suppresses cancer growth and survival. A Phase I/Ib single center study in patients with refractory/relapsed leukemias demonstrated the safety of BP1001 up to 90 mg/m² dose and the efficacy of BP1001 in combination with low dose cytarabine (LDAC) in refractory/relapsed acute myeloid leukemia (AML) patients (Ohanian, Lancet Haematol 2018). Based on pharmacokinetic (PK) considerations, the recommended Phase II dose was 60 mg/m². A phase II study was initiated to explore the clinical impact of BP1001 in combination with LDAC in untreated AML patients. Interim safety and efficacy of BP1001 + LDAC in untreated AML patients was presented at the 2018 Annual ASH Meeting. BP1001 was safely administered to 25 patients with untreated AML, who were considered unfit for standard chemotherapy. Efficacy data compared favorably to what has been reported with available options for unfit patients largely with secondary AML or adverse-risk AML. Since the Interim Data presentation, the study was amended to investigate BP1001 + decitabine combination and include myelodysplastic syndrome (MDS) patients. This is because BP1001 enhanced decitabine anti-leukemic effects in preclinical studies. Methods: This is a multi-center, open-label study with 2 parallel cohorts of BP1001 + decitabine treatment in untreated AML/high risk MDS patients and refractory/relapsed AML/high risk MDS patients who are considered by the investigator unsuitable for or refused intensive chemotherapy. BP1001 is given intravenously (IV) at 60 mg/m² twice weekly. Decitabine is given 20 mg/m² IV daily for 5 consecutive days. Each cycle is 28 days. Each cohort can enroll 19 patients, with a decision to stop or proceed to 54 patients. The primary objective of this study is to assess whether BP1001 + decitabine provides higher complete remission rates than decitabine alone (by historical comparison) in AML/high risk MDS patients. The secondary objectives of this study are to assess: Safety of BP1001 + decitabine; partial remissions and blast count reductions; overall survival, time to response and duration of response; minimal residual disease status in patients who achieve complete remission; and plasma PK profile of BP1001. The exploratory objective of this study is to evaluate the association of treatment response with cytogenetic and molecular characteristics. Clinical trial information: NCT02781883.