Enhancement of anti‐sarcoma immunity by NK cells engineered with mRNA for expression of a EphA2‐targeted CAR

Addressing unmet clinical needs in paediatric Sarcomas. Paediatric sarcomas, including rhabdomyosarcoma, Ewing sarcoma, and osteosarcoma, exhibit poor survival rates in advanced disease stages. The lack of significant therapeutic progress over the past three decades necessitates innovative treatment approaches. Advancing immunotherapy with CAR-NK cells. Natural killer (NK) cells modified with chimeric antigen receptors (CARs) represent a promising strategy to overcome the limitations of CAR-T cells, particularly in solid tumours. CAR-NK cells are associated with enhanced tumour targeting, reduced off-target effects, and improved safety profiles. EphA2 as a therapeutic target. EphA2, a receptor overexpressed in multiple paediatric sarcomas, is identified as a viable target for CAR-based immunotherapy due to its critical role in tumour progression and angiogenesis. Innovations in mRNA-based engineering. This study demonstrates the feasibility of transient mRNA transfection to engineer NK cells for CAR expression, offering a non-integrative and safer alternative to viral transduction. Enhancements in mRNA stability through chemical modifications, can further optimise protein expression. Preclinical efficacy of EphA2-CAR NK cells. EphA2-specific CAR-NK cells exhibit superior cytotoxicity against sarcoma cell lines in vitro and demonstrate significant anti-tumour activity in in vivo mouse models of rhabdomyosarcoma and osteosarcoma. Clinical translation potential. The findings establish a strong preclinical rationale for the clinical evaluation of EphA2-targeted CAR-NK therapy as a novel immunotherapeutic option for paediatric sarcomas. Future research directions: Combining EphA2-CAR NK cells with immune checkpoint inhibitors or other immunomodulatory agents could further enhance therapeutic outcomes and durability. Advanced preclinical models mimicking human tumour microenvironments are needed to refine and optimise this therapeutic approach.