ABSTRACT
Background: Chimeric antigen receptor-T (CAR-T) cells have transformed the treatment of human B cell malignancies. With the advent of CAR-T therapy, specific and in some cases severe toxicities have been documented with cytokine release syndrome (CRS) being the most frequently reported. As dogs develop tumors spontaneously and in an immunocompetent setting, they provide a unique translational opportunity to further investigate the activity and toxicities associated with CAR-T therapy. Although various adoptive cellular therapy (ACT) trials have been documented and several more are ongoing in canine oncology, CRS has not been comprehensively described in canine cancer patients. Case Presentation: Here we present the clinical and serologic changes in a dog treated with autologous CAR-T for relapsed B cell lymphoma that presented with lethargy and fever 3 days following CAR-T. Multiplexed serum cytokine profiling revealed increases in key cytokines implicated in human CRS including IL-6, MCP-1, IFNγ and IL-10 at or shortly after peak CAR-T levels in vivo. Conclusion: The observations noted in this case report are consistent with CRS development following CAR-T therapy in a canine patient. The dog represents a compelling model to study the pathophysiology of CRS and pre-clinically screen novel therapeutics to prevent and treat this life-threatening condition in the setting of a complex and naturally evolved immune system.
ABSTRACT
Immunocompetent pet dogs develop spontaneous, human-like cancers, representing a parallel patient population for the investigation of chimeric antigen receptor (CAR) therapies. We have optimized a retrovirus-based protocol to efficiently CAR transduce primary T cells from healthy and tumor-bearing dogs. While transduction efficiencies and CAR-T expansion vary among dogs, CAR expression is typically higher and more stable compared with previous protocols, thus enabling human and comparative oncology researchers to use the dog as a pre-clinical model for human CAR-T cell research. For complete details on the use and execution of this protocol, please refer to Panjwani et al. (2020).
Subject(s)
Genetic Engineering/methods , Immunotherapy, Adoptive , Neoplasms , Receptors, Chimeric Antigen/genetics , T-Lymphocytes/physiology , Animals , Cells, Cultured , Dogs , Neoplasms/therapy , Neoplasms/veterinaryABSTRACT
Multiple rodent and primate preclinical studies have advanced CAR T cells into the clinic. However, no single model accurately reflects the challenges of effective CAR T therapy in human cancer patients. To evaluate the effectiveness of next-generation CAR T cells that aim to overcome barriers to durable tumor elimination, we developed a system to evaluate CAR T cells in pet dogs with spontaneous cancer. Here we report on this system and the results of a pilot trial using CAR T cells to treat canine diffuse large B cell lymphoma (DLBCL). We designed and manufactured CD20-targeting, second-generation canine CAR T cells for functional evaluation in vitro and in vivo using lentivectors to parallel human CAR T cell manufacturing. A first-in-species trial of five dogs with DLBCL treated with CAR T was undertaken. Canine CAR T cells functioned in an antigen-specific manner and killed CD20+ targets. Circulating CAR T cells were detectable post-infusion, however, induction of canine anti-mouse antibodies (CAMA) was associated with CAR T cell loss. Specific selection pressure on CD20+ tumors was observed following CAR T cell therapy, culminating in antigen escape and emergence of CD20-disease. Patient survival times correlated with ex vivo product expansion. Altering product manufacturing improved transduction efficiency and skewed toward a memory-like phenotype of canine CAR T cells. Manufacturing of functional canine CAR T cells using a lentivector is feasible. Comparable challenges to effective CAR T cell therapy exist, indicating their relevance in informing future human clinical trial design.
