Dose Escalation and Expansion Study to Evaluate the Safety, PK, PD and Efficacy of ZE46-0134 in Adults With FLT3 Mutated or Spliceosome Mutated Relapsed or Refractory Acute Myeloid Leukemia

This is a clinical study aiming to assess pharmacokinetics, pharmacodynamics and preliminary efficacy of ZE46-0134 in patients with FLT3 and spliceosome mutated Relapsed or Refractory Acute Myeloid Leukemia

This is a Phase 1, open-label, multicenter, dose escalation, and dose optimization study to evaluate the safety, tolerability, PK, PD, and preliminary efficacy of ZE46-0134 in adult patients with relapsed or refractory AML with FLT3-ITD and/or FLT3-TKD mutations and spliceosome mutations. Patients with AML that are out-patients or hospitalized due to their AML can be enrolled in the study. The study will be run in 2 parts: Part 1 will be dose escalation and determination of MTD, and Part 2 will be dose expansion. Part 1 of the study will have 2 groups. Group 1: 3 to 6 eligible patients with FLT3 mutation will be sequentially enrolled into each of 8 planned dose level cohorts. Patients will receive up to 24 cycles (28 days each) of study treatment. For patients that continued to derive benefit after 24 cycles of treatment, continuation of ZE46-0134 therapy will be considered. Group 2: 3 to 6 eligible patients with spliceosome mutation will be sequentially enrolled into each of 4 planned dose level cohorts. Patients will receive up to 24 cycles (28 days each) of study treatment. For patients that continued to derive benefit after 24 cycles of treatment, continuation of ZE46-0134 therapy will be considered. In Part 2, the dose expansion phase will involve enrolling up to 30 patients across 2 dose cohorts (i.e., 15 patients per cohort) for Group 1 and up to 30 patients across 2 dose cohorts (i.e., 15 patients per cohort) for Group 2. ZE46-0134 will be dosed as described for Part 1 of the study. The doses used in Part 2 of the study will be determined based on the data from Part 1 of the study. Indication background information: Acute myeloid leukemia (AML) comprises a heterogeneous group of aggressive blood cell cancers that arise from clonal expansion of malignant hematopoietic precursor cells in the bone marrow (BM) and is the most commonly diagnosed adult leukemia with a median age at diagnosis is 68 years, with an overall survival (OS) rate of 29.8%. As patients age, there is a 10% decrease in 5-year OS for every additional decade of life, with a 5-year OS of 0.4% in patients age \>85 years1. Furthermore, remission rates and OS depend on a number of other factors, including cytogenetics, previous BM disorders, and comorbidities. FMS-like tyrosine kinase-3 (FLT3) is a receptor tyrosine kinase (RTK) primarily expressed on immature hematopoietic progenitors and hematopoietic stem cells. FLT3 signaling is initiated when FLT3 ligand binds to FLT3, inducing the dimerization and activation of FLT3 via autophosphorylation. This then activates downstream signaling of phosphoinositide 3-kinase/protein kinase B (PI3K/PKB), mitogen-activated protein kinase (MAPK), and JAK2/STAT5 which leads to cell proliferation and suppression of apoptosis2. FLT3 kinase is directly implicated in the pathogenesis of hematologic malignancies, particularly AML. FLT3 mutations are the most frequently identified mutations in AML patients. Activating mutations in FLT3, which are FLT3-internal tandom duplication (ITD) and FLT3 tyrosine kinase domain (TKD) mutations, account for 30% of all AML cases2. As a result of these mutations, the FLT3 receptor is continuously activated leading to the continuous activation of downstream signaling pathways, PI3K/AKT, MAPK, and signal transducer and activator of transcription (STAT5), resulting in increased cell proliferation and decreased apoptosis.