Sa1466 EUS HAS THE POTENTIAL TO EVALUATE MEMBERS OF THE TUMOR NECROSIS FACTOR (TNF) SUPERFAMILY AND IDENTIFY DRUG TARGETS ON AN INDIVIDUAL PDAC PATIENT BASIS TO GUIDE PRECISION IMMUNE-ONCOLOGY ELIGIBILITY

Abstract

The FDA has approved use of the programmed cell death-1 (PD-1) inhibitor, pembrolizumab, in MSI-High solid tumors. This is a rare event among pancreas ductal adenocarcinoma (PDAC) patients, occurring at a frequency of 0.8%. In order to decipher if other cancer immunotherapy targets are potential therapies for PDAC patients, the Tumor Necrosis Factor (TNF) Receptor Superfamily has gained prominence, due to its ability to activate antitumor T-cell immunity. Members include CD70, TNFSF4 (OX-40L) and TNFRSF9 (41BB). It is important to develop strategies to aid patient selection criteria to guide therapeutic decision-making for clinical trials. We sought to determine if EUS fine needle biopsy (FNB) treatment naïve PDAC specimens are suitable to evaluate the TNF Superfamily, and in turn identify potential targets on an individual patient basis. The cohort of 13 EUS FNB patient specimens, 7 of whom with ≥ stage III disease, a CA19-9 level of 227.5 (IQR 58-605) U/ml and overall mortality of 77% at 22.2 (IQR 13.4-36.1) months was evaluated by the Nanostring nCounter® PanCancer Immune Profiling Panel. This is a highly multiplexed mRNA gene expression panel designed to quantitate the expression of 770 genes. A ≥ 2-fold change in expression when compared to pancreas control tissue was deemed to be reflective of altered expression. The digital mRNA profiling panel revealed that 44.8% and 10% of evaluated genes had either increased or reduced expression, when compared to normal pancreas controls. Of the 30 TNF Superfamily gene members evaluated, 17 (56.7%) and 1 (3.3%) were up and downregulated in PDAC and 4 (13.3%) were each up and down regulated in surgical resection chronic pancreatitis specimens (n=3), respectively. (Figure 1) TNFRSF10C (alias TRAILR3) and TNFRSF11B (alias Osteoprotegerin) expressions were elevated in 12 (92.3%) PDAC specimens x12.2-fold (range x1.8 – x36.2 fold) and x6.5-fold (range x1.8 – x40.9 fold), respectively. CD70, an immune checkpoint, had a tumor-restricted expression pattern and was upregulated in 10 (77%) PDAC patients (x3.2-fold) but downregulated in chronic pancreatitis (x-4.23-fold). (Figure 2) EUS has a central role in guiding precision immune-oncology eligibility for clinical care and clinical trials. Using digital mRNA profiling, CD70 had a tumor-restricted expression pattern and was identified in 77% of PDAC patient specimens. Therefore, this suggests that such patients may be sensitive to monoclonal antibody therapy that targets and neutralizes CD70.View Large Image Figure ViewerDownload Hi-res image Download (PPT)