CAR T Cells for Advanced Thyroid Cancer

Project Summary The overall incidence of thyroid cancer in 2016 was estimated by the National Cancer Institute to be 64,300. Patients who present with poorly differentiated thyroid cancers frequently are refractory to standard treatment regimens and have a much worse prognosis. The median overall survival in this patient population is less than

a year. Undifferentiated or anaplastic thyroid cancers are typically not amenable to surgery and are highly resistant to RAI and virtually all other therapies. We therefore developed a chimeric antigen receptor (CAR) T cell therapy targeting intercellular adhesion molecule-1 (ICAM-1) (labeled as AIC100) to treat this aggressive

type of thyroid cancer. While a variety of cells in the body normally express low, basal levels of ICAM-1, many human cancers have upregulated levels of expression. In particular, both refractory poorly differentiated and anaplastic thyroid cancers have greatly increased expression of ICAM-1. The key aspect of our CAR T cell

technology is its ability to selectively kill tumors with over-expressed ICAM-1 while sparing normal cells with basal levels of ICAM-1 expression. To assess in vivo distribution of CAR T cells in both targeted tumors as well as non-target tissues, we have introduced the somatostatin receptor 2 (SSTR2) to follow CAR T cells over time

using the clinically approved radiolabeled tracer 68Galium-DOTATATE (Netspot). In the planned phase I study, the primary objective is to assess the safety and determine the recommended dose of AIC100 for phase II study in patients with relapsed/refractory poorly differentiated thyroid cancer and in patients with anaplastic

thyroid cancer. The secondary aims are to evaluate the efficacy of AIC100 in patients using PET/CT and RECIST (Response Evaluation Criteria In Solid Tumors) criteria, evaluate the feasibility of CAR T cell imaging by DOTATATE, determine if overall tumor response correlates with T cell distribution in tumor sites as

measured by DOTATATE and other exploratory biomarkers, and to examine pre-infusion CAR T characteristics as a predictor of clinical response. Our investigational new drug (IND) application to open phase I study of AIC100 against advanced thyroid cancers is now approved by FDA in October 2019, and patient

enrollment will commence in early 2020. As the cost for CAR T manufacturing and non-standard of care clinical costs will be sponsored by our industry collaborator (AffyImmune Therapeutics, Inc.), the major goals of this grant application are to assess the kinetics of T cell distribution by PET/CT, and determine the emergence of

high clonality T cells and associated cellular and gene expression signatures with respect to clinical response, toxicity, and survival; to correlate intrinsic CAR T fitness for survival and clonal expansion with clinical response; to optimize T cell manufacturing and next-generation CAR designs to improve the fitness of CAR T

cells toward more effective CAR T therapies against solid cancers.