Abstract 6093: A novel dual chemokine receptor-expressing CD19 CAR-iPSC-derived NK cells (TB-219) to enhance cancer homing and therapeutic efficacy

Abstract Introduction: Induced pluripotent stem cell-derived natural killer (iPSC-NK) cell therapies, characterized by exceptional homogeneity and scalable production with a single gene engineering step, are emerging as promising alternatives for the treatment of hematologic malignancies. While NK cells offer a superior safety profile compared to T cells, their limited ability to migrate to the bone marrow (BM) and lymph nodes (LN) significantly hampers therapeutic efficacy and contributes to cancer relapse. To overcome these challenges, we developed an off-the-shelf novel CD19-CAR-dEiNK (TB-219) cell therapy engineered to express dual chemokine receptors to enhance BM and LN homing, incorporating improved persistence and immune evasion capabilities. Methods: TB-219 was modified to express a CD19 CAR for targeted cytotoxicity, CXCR4 and CCR7 for improved homing to bone marrow and lymphoid tissues, and IL-15RF for autonomous survival support. β2M was knocked out to evade host immune recognition, to avoid host T cell attack. Genetic modifications were achieved via homology-directed repair, followed by iPSC differentiation and bioreactor-based expansion. In vitro assays measured cytotoxicity against CD19-positive tumor cells, homing, and persistence, while in vivo studies in mouse models assessed tumor control and survival outcomes. Results: TB-219 exhibited an 80% increase in cytotoxicity against CD19-positive cancer cells compared to unmodified NK cells at an effector-to-target (E:T) ratio of 2:1. Migration efficiency was enhanced by 200% and 400% through the expression of CXCR4 and CCR7 in transwell cell culture system, respectively. Additionally, β2M knockout effectively minimized recognition and elimination by host T cells, thereby improving persistence. Following a single i.v. administration of TB-219, no bioluminescent signals indicative of luciferase-expressing B cell leukemia cancer were detected through day 31, demonstrating complete control of cancer without evidence of relapse in the murine model. By day 39 post-administration, all subjects (Single and multiple injection) in the TB-219 treatment group demonstrated 100% survival, whereas complete mortality was observed in the tumor control group. Conclusion: The advanced engineering of TB-219 incorporates significant improvements in persistence, cancer homing, and immune evasion, positioning it as a highly promising therapeutic candidate for CD19-positive hematological malignancies. The observed improvements in cytotoxicity, targeting, and survival in preclinical models suggest TB-219 may provide a durable and efficacious treatment option. These findings warrant further clinical investigation, positioning TB-219 as a potent and accessible NK cell therapy for patients with limited therapeutic options. Citation Format: Jin-Jae Sung, Sung-Jin Park, Ji-Hee Kwon, Seung-Ki Baek, Youngwook Ki, Do-Won Hwang, Shin-Il Kim, Sung-Chang Lee. A novel dual chemokine receptor-expressing CD19 CAR-iPSC-derived NK cells (TB-219) to enhance cancer homing and therapeutic efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6093.