Optimization of TIL Cell Manufacturing for Cancer Treatment

ABSTRACT Adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TIL) has demonstrated tremendous potential for treatment of advanced solid tumors. Objective response rates ranging from 34 to 72% have been reported in patients with metastatic melanoma, with durable, complete tumor regression observed in up to 20% of treated patients. However, the current process for isolating, identifying, and expanding therapeutic TIL cells was established more than 30 years ago. TILs are stimulated with a murine anti-CD3 monoclonal antibody (OKT-3), high concentration of recombinant IL-2 produced from E. coli, and irradiated allogeneic or autologous feeder cells. Shortcomings of this process include the need for a surgically resectable tumor as a source of TIL cells, inability to grow TILs for a significant portion of patients, significant presence of regulatory T cells, and long production time. Moreover, TILs are predominantly differentiated into “old” effector T cells in vitro with a terminal phenotype, thereby reducing their long-term survival and antitumor effectiveness in vivo. Younger phenotype T cells, including stem cell memory and central memory T cells, provide superior persistence and antitumor immunity compared with effector memory T cells and effector T cells. This is consistent with recent clinical findings by Dr. Rosenberg and his group that the response of TILs against human cancer is primarily mediated by neoantigen-specific and stem-like CD8+ T cells (CD39-CD69-).Moreover, there is a high unmet need for rapidly progressing cancer types where the window of treatment is limited and where the time for TIL These shortcomings can be surmounted by improving the antibodies and cytokines used ex vivo and optimizing the combination and manufacturing process to robustly and rapidly produce TIL cells, thus, enabling TIL treatment for a broad spectrum of solid tumor patients with higher response rate and curative potential. production becomes of paramount importance. We have been using stably transfected HEK293 cells to produce proprietary antibodies and cytokines. These ancillary materials are critical in TIL manufacturing but are not intended to be part of the final cell product. O ur innovative products for TIL cell production as ex vivo therapeutics have demonstrated striking advantages over current commercial products for TIL production by improving the culture success rate, absolute expansion number, fitness and, critically, shortening the duration of TIL manufacturing while minimizing regulatory T cells. W e have formed a strategic partnership to rigorously evaluate the products and optimize the manufacturing process of TILs. Currently, TILs have been successfully cultured from small tissues of 60 pancreatic and 20 non- pancreatic tumors and scaled up using the Cocoon® Platform (Lonza) for pancreatic tumors, the most difficult TILs to grow so far. Critically, the TILs manufactured in clinical scale has a high frequency of CD8+CD39- CD69- T cells and the reactivities of TILs against neo-antigens were robustly detected by IFN release. The data obtained thus far show a focused, yet diverse TCR repertoire. In addition to a more general TCR analysis in TIL, we were able to link individual TCR clonotypes to individual private target antigens and to trace these back to the TIL product and to the corresponding harvested tumor tissue, respectively.Specific Aim. To determine whether anti-CD137HC and/or IL-12HC enriches antigen-specific T cells and anti- TGFHC, anti-IL-6HC and/or anti-IL-23HC blunts Th17 differentiation and IL-17 release; select top Expi293 cell clones and complete pilot scale production of proprietary antibodies and cytokines critical for TIL manufacturing.The strategic collaborator will validate the efficacy and consistency of our products and pursue regulatory clearance for clinical manufacturing of TILs from pancreatic patients. Importantly, a Phase 1 clinical trial for metastatic or recurrent pancreatic cancer patients has been planned, the first patient is anticipated to be enrolled as soon as 2023.