Bi-specific CAR-iNKT cell immunotherapy for high-risk KMT2A-rearranged leukemia outperforms CAR-T in an NKG2D-dependent manner and eradicates leptomeningeal disease

Ren, H.; Elliott, N.; Lye, B.; Shohan, M.; Cross, J.; Field, L.; Ponnusamy, K.; Rice, S.; Jackson, T.; Leontari, I.; Ouazzani, N.; Thomas, R.; Inglott, S.; Bartram, J.; Smith, O.; Bond, J.; Roberts, I. A.; Halsey, C.; Bashford-Rogers, R. J. M.; Milne, T.; Roy, A.; Karadimitris, A.

doi:10.1101/2025.01.22.633541

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bioRxiv · 10.1101/2025.01.22.633541

Bi-specific CAR-iNKT cell immunotherapy for high-risk KMT2A-rearranged leukemia outperforms CAR-T in an NKG2D-dependent manner and eradicates leptomeningeal disease

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Abstract

Current therapies, including autologous CAR-T immunotherapy, fail to cure half of infants with KMT2A-rearranged acute lymphoblastic leukemia (KMT2Ar-ALL). Here we deploy allogeneic iNKT cells, innately more powerful effectors than T cells, and equip them with CD19- and/or CD133-targeting CARs. Compared to mono-specific counterparts and bi-specific CAR-T, CD19-CD133 bi-specific CAR-iNKT have more potent anti-leukemia activity, they effectively target CAR antigen-low leukemia, eradicate medullary and leptomeningeal leukemia and induce sustained remissions without discernible hematologic toxicity. Mechanistically, dynamic CAR- and CAR antigen-dependent upregulation of the activating innate receptor NKG2D and its engagement by corresponding ligands on KMT2Ar-ALL cells lead to more potent anti-leukemia effect of CAR-iNKT over CAR-T cells, including against CAR antigen-negative leukemia. Thus, by engaging with two different types of leukemia-associated targets, CAR-iNKT provide a powerful platform for the treatment of KMT2Ar-ALL. This approach can be readily adapted for other high-risk malignancies, including those with otherwise difficult to target leptomeningeal involvement.

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Ren, H., Elliott, N., Lye, B., Shohan, M., Cross, J., Field, L., Ponnusamy, K., Rice, S., Jackson, T., Leontari, I., Ouazzani, N., Thomas, R., Inglott, S., Bartram, J., Smith, O., Bond, J., Roberts, I. A., Halsey, C., Bashford-Rogers, R. J. M., Milne, T., Roy, A., Karadimitris, A.. 2025-01-24. Bi-specific CAR-iNKT cell immunotherapy for high-risk KMT2A-rearranged leukemia outperforms CAR-T in an NKG2D-dependent manner and eradicates leptomeningeal disease. https://doi.org/10.1101/2025.01.22.633541

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