Adoptive immunotherapy trials using genetically modified natural killer (NK) and T cells with redirected specificity against B cell malignancies have demonstrated therapeutic efficacy. Two early-phase clinical trials have been initiated at The University of Texas M. D. Anderson Cancer Center to evaluate the safety and efficacy of adoptive transfer of autologous and allogeneic T cells expressing a CD19-specific chimeric antigen receptor (CAR) into patients with advanced B-cell malignancies. These CD19-specific CAR+ T cells are selectively propagated in vitro in the presence of irradiated artificial antigen presenting cells (aAPC) expressing co-stimulatory molecules that sustain their proliferation to clinically-sufficient numbers in compliance with current good manufacturing practice (cGMP) for Phase I/II trials. This conventional culturing process requires 28 days to generate the required >1010 CAR+ T cells for each infusion. Reduction of the time required to generate clinically sufficient numbers in tissue culture will reduce manufacturing costs significantly and will yield a clinical product in which the CAR+ T cells have increased replicative potential and are less differentiated. To enhance the production process, we propose to develop novel co-culture protocol that utilizes magnetic co-levitation to increase the contact interface between CAR+ NK or T cells and the stimulating aAPCs to significantly improve the kinetics of numeric expansion of CAR+ lymphocytes with desired specificity and preservation of memory phenotype. Our long-term goal is to develop a cGMP-compliant protocol based on three-dimensional (3D) magnetic levitation co-cultures for the rapid and specific production of CAR+ T and NK cells to support ongoing immunotherapy trials. Our novel expansion method is based on the central hypothesis that increasing the number and duration of contact points between CAR+ T or NK cells and aAPCs will accelerate the proliferation of the targeting cells, yielding clinically sufficient number of cells in less time. In this Phase I SBIR proposal, we aim to develop and optimize 3D cell magnetic levitation co-culture conditions to improve the propagation of CAR+ T cells by magnetic nanoparticle labeling of aAPCs, NK, and T cells and co-culturing in 3D to maximize expansion of the genetically modified CD19-specific NK and T cells. Development of this expansion methodology will significantly impact the treatment, management, and cost of adoptive cell therapies of B cell malignancies.
Adoptive T cell therapy offers a promising approach for treating B cell malignancies. The process of preparing these targeting T cells for transplantation involves isolation of antigen-specific cells and expansion in vitro in the presence of target antigen. The process of preparing these cells is lengthy, taking up to 28 days. It is recognized that reducing the preparation time in culture will save manufacturing costs will yield less differentiated T cells that have increased targeting potential. The proposed work will implement and optimize T cell expansion methods that are based on magnetically levitated cell cultures to produce clinically sufficient number of T cells in one-third of the time required to manufacture by conventional methods.
