Person:

Maus, Marcela

Novel cellular therapies outside of traditional hematopoietic stem cell transplantation or hematopoietic progenitor cell (HPC) therapy are currently under evaluation in clinical trials across the United States and around the world. Several cellular products, e.g., CD19-directed Chimeric Antigen Receptor (CAR) T cells, are poised for FDA approval and thus increased use at a wider range of academic centers within the next year, with the likelihood of dissemination to standard oncology practice once safety is confirmed. However, these therapies entail some unique challenges in terms of logistics of delivery and toxicity management. Building on experiences and Standards established for HPC programs, the Foundation for the Accreditation of Cellular Therapy (FACT) has established new Standards specific to the use of Immune Effector Cells (IEC), including gene-modified T cells and natural (NK) cells. These Standards specify the clinical and quality infrastructure to facilitate safe administration of immune effector cells and formalize subsequent monitoring and reporting of patient outcomes to enable continual process improvement. Below we detail why these standards came into being, what they entail, and how a clinical team might access educational materials and implement these Standards. We propose that these Standards will be increasingly useful and relied up on as institutions and clinical service lines seek access to these treatment for their patients. FACT will begin accrediting programs that meet these new Standards for clinical administration of Immune Effector Cells in 2017.

Chimeric antigen receptor (CAR) T-cell therapy represents a revolutionary treatment for haematological malignancies (i.e. B-ALL). However, the success of this type of treatment has not yet been achieved in solid tumors. One hypothesis is that the immunosuppressive nature of the tumor microenvironment (TME) influences and affects the efficacy of adoptive immunotherapy. Understanding the role of the TME and its interaction with CAR T-cells is crucial to improve the potency of adoptive immunotherapy. In this review, we discuss the strategies and potential combinatorial approaches recently developed in mouse models to enhance the efficacy of CAR T-cells, with particular emphasis on the translational potential of these approaches.

Immunotherapy is the revolution in cancer treatment of this last decade. Among multiple approaches able to harness the power of the immune system against cancer, T cell based immunotherapies represent one of the most successful examples. In particular, biotechnological engineering of protein structures, like the T cell receptor or the immunoglobulins, allowed the generation of synthetic peptides like chimeric antigen receptors and bispecific antibodies that are able to redirect non-tumor specific T cells to recognize and kill leukemic cells. The anti-CD19/CD3 bispecific antibody blinatumomab and anti-CD19 chimeric antigen receptor T cells (CART19) have produced deep responses in patients with relapsed and refractory B-cell acute leukemias. However, although the majority of these patients responds to anti-CD19 immunotherapy, a subset of them still relapses. Interestingly, a novel family of leukemia escape mechanisms has been described, all characterized by the apparent loss of CD19 on the surface of leukemic blasts. This extraordinary finding demonstrates the potent selective pressure of CART19/blinatumomab that drives extreme and specific escape strategies by leukemic blasts. Patients with CD19-negative relapsed leukemia have very poor prognosis and novel approaches to treat and ideally prevent antigen-loss are direly needed. In this review we discuss the incidence, mechanisms and therapeutic approaches for CD19-negative leukemia relapses occuring after CD19-directed T cell immunotherapies and present our future perspective.