Abstract 5943: Development of a <i>SMART</i> theranostic agent for precision pancreatic cancer therapeutics
Authors: Edward A. Motea, Jarrett J. Smith, Oluwasijibomi Ketiku
Journal: Cancer Research (2024)

Abstract Pancreatic cancer is predicted to emerge as the second leading cause of cancer-related deaths in the United States by 2030. Pancreatic ductal adenocarcinoma (PDAC) - the most common form of pancreatic cancer - is often diagnosed as metastatic disease and has demonstrated the least improvement in overall survival over the last three decades with incidence rising by 0.5% to 1.0% per year due in part to lack of effective and tumor-selective treatment strategies. One approach to reduce host toxicity is the development of novel molecules and innovative therapeutic approaches that are nontoxic to normal cells but can be activated only under tumor-specific conditions for lethality, which we coined as SMART (Selective Method of Activation for Response in Tumors) therapeutic agents. We utilized explicit properties and biomarkers present in PDAC tumors but not in normal tissues to develop a SMART DNA-damaging anti-cancer agent with both therapeutic and diagnostic (theranostic) activities. We evaluated the tumoricidal effect of our SMART agent using long-term survival assays in PDAC cell lines and 3D co-culture spheroids, as well as in tumor xenograft model studies in mice. We also tested the ability of our SMART agent to treat, detect/diagnose (via click chemistry), and identify critical resistance mechanisms (via proteomics) as a single agent or as a chemosensitizer with predictive tumor biomarkers for tumor-selective therapeutic response. We found that our SMART small molecule induces tumor-selective lethal effects as a monotherapy or in combination with DNA repair inhibitors or small molecules known to generate hydrogen peroxide (H2O2) in a tumor-selective manner for activation. Using “click” chemistry, we detected and quantified the incorporation of our SMART small molecule as a DNA-damaging agent via flow cytometry that correlated with therapeutic response, which is a feature that could facilitate the stratification, treatment monitoring, and management of patients with pancreatic cancers. We also found that our SMART agent is less toxic and more effective as a monotherapy than cisplatin in PDAC cell line-derived xenograft studies in mice. Overall, our novel SMART theranostic agent could provide a significant advancement as they are preferentially activated under tumor-specific conditions to induce tumor-selective therapeutic response. Furthermore, the diagnostic component our SMART agent could provide oncologists with essential information to make rapid clinical decisions on treatment strategies. Our SMART agent is also remarkably versatile as it can be utilized as a chemosensitizer or as a chemical probe to identify targetable vulnerabilities to potentiate its therapeutic effects at lower doses. Citation Format: Edward A. Motea, Jarrett J. Smith, Oluwasijibomi Ketiku. Development of a SMART theranostic agent for precision pancreatic cancer therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5943.