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-
TGFHC, 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.