Acute Myeloid Leukemia (AML) resulted in over 130,000 deaths worldwide in 2021. Current treatment methods, such as chemotherapy and radiation, enable about 65% of new patients to achieve remission; however, two-thirds of these patients experience a relapse within five years. The treatment of relapsed or refractory AML presents significant challenges, primarily due to tumor heterogeneity and antigen escape, contributing to high mortality rates. To improve AML treatment, we developed a CD33 targeting Tri-Specific Killer Engager (TriKE), currently being tested clinically. To address the complexities of AML, we designed novel TriKE-Poly Antigen Cytokine Complexes (TriKE-PACCs) designed to enhance the capabilities of NK cells against tumor heterogeneity and antigen escape. These innovative molecules combine the CD33 TriKE—which consists of an anti-CD16 sdAb, an IL-15 moiety, and an anti-CD33 scFv—with a PACC arm that features an anti-tumor-antigen sdAb linked to an IL-15Ra, binding to IL-15 present in the TriKE. This dual antigen targeting approach boosts NK cell proliferation and persistence while improving tumor targeting and killing through antibody-dependent cellular cytotoxicity (ADCC). In our studies, we analyzed the phenotypic signatures of various AML cell lines and 20 AML patient samples to assess the expression of surface markers such as CD33, CD83, CLEC12a, B7H3, CD70, and Mesothelin. We are developing modular TriKE-PACC combinations to tailor therapies to patients' unique AML profiles. Additionally, we created CRISPR knockout AML cell lines to model antigen escape and tumor heterogeneity to evaluate the efficacy of the TriKE-PACCs’ tumor-targeting components. Our findings indicated that dual targeting via TriKE-PACCs significantly enhances NK cell activation via increased CD107a expression, IFNg, and TNFa production and improved NK cell killing of AML cells compared to IL-15 or CD33 TriKE treatments alone. We believe this novel modular approach offers substantial clinical potential for treating AML.