FT538, iPSC-derived NK cells, enhance AML cell killing when combined with chemotherapy

Induced pluripotent stem cell (iPSC)-derived natural killer (NK) cells offer an opportunity for a standardized, off-the-shelf treatment with the potential to treat a wider population of acute myeloid leukaemia (AML) patients than the current standard of care. FT538 iPSC-NKs express a high-affinity, noncleavable CD16 to maximize antibody dependent cellular cytotoxicity, a CD38 knockout to improve metabolic fitness, and an IL-15/IL-15 receptor fusion preventing the need for cytokine administration, the main source of adverse effects in NK cell-based therapies. Here, we sought to evaluate the potential of FT538 iPSC-NKs as a therapy for AML through their effect on AML cell lines and primary AML cells. We observed that FT538 iPSC-NKs induce effector-to-target cell ratio dependent apoptosis in cell lines and primary AML cells, including cells from high-risk patients. Flow cytometric analysis revealed that FT538 iPSC-NKs induce AML cell death when combined with the AML therapies: cytarabine, venetoclax and gilteritinib. Moreover, cytarabine did not affect FT538 iPSC-NK viability, suggesting that iPSC-derived NK therapies and chemotherapy may be a promising treatment combination. This study provides the basis for further study of iPSC-derived NK cell therapies as a treatment option for high-risk AML patients, particularly those with disease resistant to standard therapies.