Off-the-Shelf, Multiplexed-Engineered iPSC-Derived CD33 CAR-NK Cells for Treatment of Acute Myeloid Leukemia

Immune cell therapy has become a cornerstone in cancer therapy. However, the needs for new therapies targeting acute myeloid leukemia (AML) and solid tumors remains high. Natural Killer (NK) cells derived from genetically engineered human induced Pluripotent Stem Cells (iPSCs) hold great potential to become the next-generation allogeneic cell therapy products. NK cells exert anti-tumor activity through the net balance of stimulatory and repressive signals from various activating and inhibitory receptors. Some of the activating ligands for NK cell activation are highly expressed on the AML blasts as well as the solid tumors. Thus, the off-the-shelf iPSC-derived NK cell product is a promising clinical drug candidate for the treatment of AML and solid tumors. In this study, we demonstrated that human iPSCs-derived NK (iNK) cells mediate potent cytotoxicity to several AML cell lines and solid tumor cell lines that highly express NKG2D ligands. Further, we developed CD33-CAR iNK (QN-023a) with 4 anti-tumor functional modalities, including a CAR optimized for NK cell biology that targets AML antigen CD33, a high-affinity, non-cleavable CD16 (hnCD16) to enhance antibody-dependent cell-mediated cytotoxicity (ADCC), an IL-15 molecule to increase the persistence of allogeneic cells in transplant patients, a CD38 knockout to effectively avoid fratricide of CAR-NK cells and acquire synergetic function with daratumumab. Here, we first engineered a small library of human iPSC clones with desired genetic modifications. We then differentiated the engineered human iPSC clones into NK cells and conducted both in vitro and in vivo screening by using a variety of AML cell lines. We identified QN-023a as the lead, who demonstrated superior anti-tumor activity among the candidates both in vitro and in NOG mouse model. QN-023a show potent anti-tumor activity against a variety of AML cell lines and primary AML blasts from patients, regardless of the expression level of NKG2D ligands on these tumor cells. QN-023a cells can be mass-produced in a cGMP process, have phenotype comparable to healthy donor NK cells, and are functionally potent against multiple AML tumor models. When administered in combination with daratumumab, QN-023a demonstrated superior ADCC compared to unmodified iPSC-derived NK cells against primary AML blasts from patients. Together, we have engineered iPSC-derived QN-023a NK cells as promising clinical drug candidates for treatment of AML.

No relevant conflicts of interest to declare.