Kanagaraju Ponnusamy, Klesti Karaxhuku, Yuchao Jiang, Lyra Randzavola, Hongwei Ren, Ilia Leontari, Bryan Lye, Mehmood Zaidi, Edward J Bartlett, Edward W Tate, Vasileios Pardalis, Dimitrios Leonardos, Reza Nadafi, Irene Sarkar, Rogier M Reijmers, Marco Bua, Maria Atta, Alexia Katsarou, Irene Ag Roberts, Aristeidis Chaidos, Anastasios Karadimitris
iNKT cells are emerging as a highly promising immunotherapy platform for the treatment of cancer. To maximise the anti-cancer activity of CAR-iNKT against the blood cancer multiple myeloma we investigated optimal CAR designs and their combination with new iNKT-specific engagers. We find that amongst five different CAR endodomains, underpinned by increased avidity and a cross talk between Plexin D1 on CAR-iNKT and Semaphorin 4 A on myeloma cells, BCMA CD28z CAR-iNKT exert the highest anti-myeloma activity. Notably, CD28z CAR-iNKT outperform their CAR-T counterparts. To expand the anti-myeloma potential of CAR-iNKT, we designed and validated a high efficacy BCMA iNKT-specific engager which exerts significant anti-myeloma activity in conjunction with adoptively transferred iNKT cells. Finally, combined, dual target therapy with FCRL5 CAR-iNKT and BCMA iNKT engagers outperforms FCRL5 CAR-iNKT and limits immune escape of FCRL5-negative myeloma. Thus, optimised iNKT-based, dual-target, dual-modality immunotherapy has enhanced anti-tumor activity against multiple myeloma and potentially other malignancies.