Generating Revitalized Stem Cell-Engineered CAR-NKT Cells for the Treatment of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a rare but highly aggressive cancer of the pleural lining, characterized by poor prognosis and limited treatment options. While mesothelin (MSLN)-targeted chimeric antigen receptor (CAR)-engineered T (MCAR-T) cell therapy has shown promise in early clinical trials, current autologous approaches are constrained by complex manufacturing processes and delayed treatment timelines, that are particularly challenging for patients with rapidly progressing MPM disease. Here, we report the development of allogeneic IL-15–enhanced, MCAR-engineered invariant natural killer T (Allo15MCAR-NKT) cells, generated via hematopoietic stem and progenitor cell engineering and a clinically guided, feeder-free culture system. This platform enables the scalable production of CAR-NKT cells with high yield, purity, and clinical-grade suitability. Allo15MCAR-NKT cells exhibit potent antitumor activity in vitro and in multiple in vivo models of MPM, mediated through diverse tumor-targeting mechanisms. These cells also demonstrate a revitalized immunophenotypic profile, characterized by low expression of exhaustion markers and immune checkpoints, suggesting sustained functional potential. Importantly, the therapy exhibits a strong safety profile, with minimal signs of graft-versus-host disease (GvHD), cytokine release syndrome (CRS), or off-tumor toxicity. Collectively, this study presents a clinically translatable, off-the-shelf allogeneic CAR-NKT cell therapy with robust antitumor efficacy and a favorable safety profile for the treatment of MPM. Overall design: Gene expression profiling of therapeutic cells products including MCAR-T, PBMC-MCAR-NKT-IL15, PBMC-NK, and Allo15MCAR-NKT (Re-analysed Samples from PRJNA1128571/GSE270820: MCAR-T---GSM8352657, Allo15MCAR-NKT---GSM8352672; and PRJNA1299401/GSE304213: PBMC-MCAR-NKT-IL15---GSM9145254)