TIM-3 in AML: a janus-faced orchestrator of immune exhaustion and leukemic self-renewal

Acute Myeloid Leukemia (AML) remains a therapeutic challenge due to relapse driven by therapy-resistant leukemic stem cells (LSCs) and a profoundly immunosuppressive microenvironment. The immune checkpoint T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) emerges as a uniquely Janus-faced orchestrator in AML pathogenesis. This review synthesizes emerging evidence that TIM-3 operates dually: on one edge, it acts as an important contributor to immune exhaustion, suppressing T-cell, natural killer (NK) cell, and dendritic cell function within the AML niche. On the second edge, TIM-3 serves as a cell-autonomous driver of leukemic stemness, where it marks functional LSCs and promotes their self-renewal, survival, and metabolic reprogramming via non-canonical signaling networks like β-catenin and nuclear factor kappa B (NF-κB). TIM-3 is also detectable on subsets of immature blasts, but the biologic and clinical meaning of blast-level expression appears more context dependent than its LSC-associated role. This dual biology positions TIM-3 at a compelling therapeutic intersection. We examine the current landscape of TIM-3-targeted agents, from monoclonal antibodies like sabatolimab to bispecifics and CAR-T cells, and critically evaluate rational combination strategies with hypomethylating agents, venetoclax, and other immunotherapies. Finally, we discuss the challenges of patient stratification, resistance mechanisms, and on-target toxicity, outlining a roadmap for converting the multifaceted biology of TIM-3 into transformative clinical benefit for AML patients.