Dynamics of Resistance Emergence to Azacitidine-based Therapies in Acute Myeloid Leukemia

Overall Response (CR+CRh+Cri)

Acute myeloid leukemia (AML) is a malignancy of aging endowed with poor prognosis. The
 combination of the hypomethylating agent azacitidine (AZA) with the BCL-2 inhibitor
 venetoclax (VEN) is the first-line treatment of older AML patients but is endowed with
 substantial resistance. The project leverages functional precision oncology, single-cell
 studies and mouse experiments to dissect the mechanisms of primary and adaptive resistance to
 AZA/VEN. The primary objective is to prospectively validate an ex vivo drug sensitivity
 testing (DST) assay as predictor of primary resistance to first-line AZA/VEN in 100 unfit AML
 patients. The study will also explore whether newer DST assays with enhanced niche mimicry
 can improve on the standard assay.
 
 By serially interrogating the short-term fate of both leukemic and immune cells upon AZA/VEN
 exposure in patients primed towards refractoriness, transient or prolonged remission, the aim
 is to dissect the cell-intrinsic and immune-mediated mechanisms of primary versus adaptive
 resistance. A parallel flow cytometry study will interrogate the role of senescence in
 AZA/VEN activity. These translational studies will be mirrored by experiments in a
 transplantable AML model derived from syngeneic mice harboring the age-related Tet2-/-
 leukemia-predisposing genotype. Lineage tracing single-cell experiments will backtrack
 AZA/VEN resistance to determine whether it is driven by selection or adaptation. The
 actionable stress sensor Pml will be invalidated in the same model to determine whether
 Pml-driven senescence contributes to AZA/VEN anti-leukemic activity in vivo. The project will
 pave the way to the clinical implementation of functional precision oncology in a high-risk
 malignancy. By simultaneously interrogating cell-intrinsic and immune-mediated drug
 resistance in vivo in a prospective patient cohort mirrored by controlled mice experiments,
 the project will provide a framework for the integrative analysis of drug resistance in
 cancers.