Cytotoxic T lymphocytes (CTLs) directed to nonviral tumor-associated antigens do not survive long term and have limited antitumor activity in vivo, in part because such tumor cells typically lack the appropriate costimulatory molecules. We therefore engineered Epstein-Barr virus (EBV)-specific CTLs to express a chimeric antigen receptor directed to the diasialoganglioside GD2, a nonviral tumor-associated antigen expressed by human neuroblastoma cells. We reasoned that these genetically engineered lymphocytes would receive optimal costimulation after engagement of their native receptors, enhancing survival and antitumor activity mediated through their chimeric receptors. Here we show in individuals with neuroblastoma that EBV-specific CTLs expressing a chimeric GD2-specific receptor indeed survive longer than T cells activated by the CD3-specific antibody OKT3 and expressing the same chimeric receptor but lacking virus specificity. Infusion of these genetically modified cells seemed safe and was associated with tumor regression or necrosis in half of the subjects tested. Hence, virus-specific CTLs can be modified to function as tumordirected effector cells. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptThe promise of tumor antigen-specific T lymphocytes for the treatment of melanoma and EBVassociated malignancies 1-7 has led to efforts to retarget effector T cells and thereby extend the range of tumors that they can treat. A common strategy has been to introduce a synthetic receptor with an antigen-binding domain from an antibody coupled to a signal-transducing endodomain derived from the native T cell receptor into activated T cells (ATCs) 8 . These chimeric antigen receptors (CARs) thus have the specificity of an antibody coupled to the cytotoxic effector mechanisms of the T cell. To date, however, this strategy has had only limited success, owing in part to the lack of essential costimulatory signals to the T cell during engagement of its CAR and perhaps also to the introduction of the CAR into regulatory T (T reg ) cells, as well as into conventional T effector cells 9 . Consequently, even when the infusion of large numbers of CAR-bearing T cells is supplemented with exogenous growth factors, such as interleukin-2 (IL-2), survival in vivo is poor and antitumor activity minimal 10,11 . By contrast, small numbers of CTLs with native receptor specificity directed to persistent human viruses such as EBV can survive long term after infusion and eradicate even bulky EBV-associated malignancies, such as Hodgkin's disease and nasopharyngeal cancer 2,12-14 . A contributing factor to the superior survival and function of EBV-specific CTLs is that engagement of their native receptors by EBV-infected B cells produces extensive co-stimulation during their preparation ex vivo and by encounters with (latent) viral antigens on antigen-presenting cells in vivo 15 .This knowledge has given rise to the concept of engineering antigen-specific CTLs to provide them with a second specificity for ...

We generated MHC-independent chimeric antigen receptors (CARs) directed to the GD2 antigen expressed by neuroblastoma tumor cells and treated patients with this disease. Two distinguishable forms of this CAR were expressed in EBV-specific cytotoxic T lymphocytes (EBV-CTLs) and activated T cells (ATCs). We have previously shown that EBV-CTLs expressing GD2-CARs (CAR-CTLs) circulated at higher levels than GD2-CAR ATCs (CAR-ATCs) early after infusion, but by 6 weeks, both subsets became low or undetectable. We now report the long-term clinical and immunologic consequences of infusions in 19 patients with high-risk neuroblastoma: 8 in remission at infusion and 11 with active disease. Three of 11 patients with active disease achieved complete remission, and persistence of either CAR-ATCs or CAR-CTLs beyond 6 weeks was associated with superior clinical outcome. We observed persistence for up to 192 weeks for CAR-ATCs and 96 weeks for CAR-CTLs, and duration of persistence was highly concordant with the percentage of CD4+ cells and central memory cells (CD45RO+CD62L+) in the infused product. In conclusion, GD2-CAR T cells can induce complete tumor responses in patients with active neuroblastoma; these CAR T cells may have extended, low-level persistence in patients, and such persistence was associated with longer survival. This study is registered at www.clinialtrials.gov as #NCT00085930.