A Study of Rebecsinib for Patients With Relapsed/Refractory Secondary Acute Myeloid Leukemia or High Risk Myelofibrosis

The primary objective is to determine the maximum tolerated dose or biologically active dose of rebecsinib when given on days 1, 4, 8, and 11 of each 28 days cycle to patients with relapsed or refractory secondary acute myeloid leukemia (sAML), who have evolved from Myelodysplastic Syndrome (MDS) or myeloproliferative neoplasms (MPNs), or patients with higher-risk myelofibrosis. The other primary objective is to determine the safety and tolerability of rebecsinib by ongoing evaluation of adverse events (AEs), as assessed according to the NCI Common Terminology Criteria for Adverse Events (NCI CTCAE v5.0). Study outcomes will be measured by adverse event data, response rates, progression free survival and overall survival. Pharmacodynamics and plasma pharmacokinetics of rebecsinib will be explored.