Predicting tumor-immune response to checkpoint inhibitors using a novel patient-derived live tumor explant model.

Abstract

e20035 Background: Immunotherapy has emerged as a powerful treatment paradigm wherein therapies primarily target immune components. For example, blockade of PD-1 and PD-L1 offers effective treatment options for patients with aggressive tumors such as head and neck squamous cell carcinoma (HNSCC) and in non-small cell lung carcinoma (NSCLC). However, clinical responses to immotherapy vary widely among patients. There is an unmet need to understand these disparities at the individual patient level. Rationally combining checkpoint inhibitors may address many of these underlying challenges. Methods: Here, we describe a patient-derived ex-vivo platform technology CANscript™, which captures the 3D profiles of native tumor microenvironment by incorporating tumor tissue, autologous immune cells, and immune-targeted agents. Utilizing late stage HNSCC and NSCLC patient tumors we interrogated the phenotypic changes in the tumor-immune contexture in response to standard-of-care agents, PD-1 and PD-L1 inhibitors. Flow cytometry and immunohistochemistry profiling of CD8, CD45, FOXP3, CXCR4, CD68, PDL1, PD1), cytokine profile (IL6, IL8, IFN-g, IL12 and others), and tumor proliferation/apoptosis were measured. Results: The data suggest that PD-1 and PD-L1 blockade induced patient-specific response, which was characterized by differential distribution and infiltration of CD8+ and CD4+ lymphocytes, distinct patterning of cytokines linked to functional dysregulation, and changes in tumor proliferation and apoptosis. Interestingly, the data demonstrated unique immune signatures associated with single agent vs. combination therapy that imply functionally distinct mechanisms of orchestration of response. Conclusions: Our data highlights the translational underpinnings of of CANScript™ as an ex vivo platform for predicting patient driven therapeutic response of immune checkpoint inhibitors where distinct tumor-immune networks influence clinical response to therapy. Information obtained from this study can re-shape our understanding of patient selection and rational combinations for novel immune checkpoint inhibitors.

Benefits of functional assays in personalized cancer medicine: more than just a proof-of-concept

“…Closer to bedside, changes in immune activity against tumour cells have been measured in melanoma explant models through the histological identification of relevant actors and subsequent measurement of both immune infiltration and inter-cell distance, pre- and post-treatment with anti-PD-1 nivolumab 153 . Patient-specific responses to ICI have also been observed using the CANscript TM platform 163 . Regarding the specific targets PD-1/PD-L1, the ability of CoDx to predict tumour sensibility to immunotherapies has been inconsistent so far, especially due to the variable expression of these markers in space and time 7 .…”