Enhancing the iNKT cell immunotherapy platform by combining optimised CAR endodomains with novel iNKT engagers

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 novel 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 4A 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. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=159 SRC="FIGDIR/small/683869v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@11e843corg.highwire.dtl.DTLVardef@7bb408org.highwire.dtl.DTLVardef@1687b84org.highwire.dtl.DTLVardef@8542ea_HPS_FORMAT_FIGEXP M_FIG C_FIG