The Role of the Central Memory Phenotype in Predicting Response to PD-1 Inhibition in Pre-clinical Models of Oral Cancer

Squamous cell carcinoma of the head and neck (HNSCC) is the sixth most common neoplasm in the world and despite advances in treatment, the 5-year survival remains approximately 50%. Because of the need for new therapies, the possibility of immunotherapeutic approaches for HNSCC patients has gained interest. Interest in this has continued as more than half of the subjects enrolled to an ongoing clinical trial in patients with with oral squamous cell carcinoma (OCSCC) have responded to neoadjuvant presurgical Nivolumab therapy. Additionally, unlike other solid tumors it appears responders have higher proportions of CD4+ tumor-infiltrating lymphocytes (TILs) whereas non-responders have an increase in CD8+ TILs population. Furthermore, the investigator's data suggests that response to PD-1 blockade is associated with an increase in CD45RA- CD62L+ population or central memory phenotype within TIL whereas progression of disease correlates with an increase in the CD45RA- CD62L- population or effector memory phenotype.

As previously demonstrated in several other tumor types the magnitude of response to immunotherapy directly correlates to presence of antigen specific T cells within the tumor and tumor microenvironment. Therefore, the long-term objective of this project is to identify predictive biomarkers of immune response from either TILs or tumor cells from patients with head and neck squamous carcinoma. To achieve this goal the overall objective of the current study is to develop a pre-clinical murine models in an effort to more completely evaluate the memory phenotype of TILs before and after PD-1 inhibition and to subsequently to determine the efficacy of TIL therapy in this mouse model of oral cancer. This project will test a central hypothesis that TILs derived from responders to neoadjuvant pre-surgical PD-1 inhibition in both a patient derived xenograft mouse model of oral cancer.