Dual-functional Nanocarrier for Improved Immunochemotherapy of Acute Myeloid Leukemia

Advances with the 7 + 3 regimen and liposomal CPX-351 have significantly improved the treatment of acute myeloid leukemia (AML); however, challenges like drug resistance and immune evasion persist. Despite the demonstrated potential of immunotherapy in treating several types of solid tumors, its impact on the treatment of AML remains limited. To address these challenges, we engineered an ultrasmall (~ 15 nm) cytarabine (AraC)-based polymeric micelle nanocarrier (PAraC) for efficient AML cell uptake and bone marrow niche targeting. scRNA-seq and real-world dataset analysis identified upregulated TLR7/8 in malignant AML cells, particularly after 7 + 3 treatment, supporting the inclusion of the TLR7/8 agonist R848 in our combination therapy. Our strategy integrates smart co-delivery of AraC, daunorubicin (Daun), and R848 using the PAraC platform. This triple nano-combination (PAraC/Daun/R848) demonstrated potent antitumor efficacy, outperforming CPX-351 and PAraC/Daun in multiple leukemia models, including murine and patient-derived xenografts (PDX) AML models and AraC-resistant acute lymphoblastic leukemia (ALL) model. Notably, PAraC/Daun/R848 reversed immunosuppressive phenotypes seen with CPX-351 or PAraC/Daun and induced robust leukemia cell maturation. With its modular design, efficient delivery, and remarkable preclinical performance, the PAraC platform holds immense promise for clinical translation, offering a new frontier for immunotherapeutic interventions in AML.