Integrating Human Genetics and Protective Genome Editing to Enable ADGRE2-Directed AML Therapy

Acute myeloid leukemia (AML) remains a major therapeutic challenge due to extensive disease heterogeneity and lack of cancer-specific antigens. ADGRE2 has emerged as a promising AML target with broad expression in AML patient blast and leukemic stem cell-enriched populations. However, comparable expression in healthy hematopoietic stem and progenitor cells (HSPCs) and myeloid lineages suggests a high susceptibility to on-target, off-tumor myelotoxicity with ADGRE2-targeted therapies. Guided by human genetics data identifying loss-of-function variants, we evaluated whether ADGRE2 is dispensable in hematopoietic stem cells as a protective approach for transplant-based shielding from ADGRE2-directed therapies. Using CRISPR-Cas9 and adenine base editors, we achieved high-efficiency ADGRE2 knockout (>94%) in HSPCs with corresponding protein loss without impairing cell viability, differentiation, and cytokine release in vitro, or long-term engraftment, multilineage differentiation, and persistence of gene editing in mouse xenografts. We also developed novel ADGRE2-specific chimeric antigen receptor (CAR) T cells that demonstrated potent cytotoxicity against AML cells, even at low antigen levels. Together, these findings establish ADGRE2 as a compelling AML target and provide a framework for hematopoietic stem cell transplant with protective gene editing to enable ADGRE2-directed immunotherapies while minimizing myelotoxicity.