Deep mechanistic profiling of immune oncology (I-O) drug combinations in cancer patients with CIVO (R) intratumoral microdosing and NanoString GeoMx DSP

Abstract Despite over four thousand clinical trials investigating combinations of various anti-cancer agents with immune checkpoint inhibitors (CPI), few have demonstrated significant clinical improvement over CPI alone. This indicates a need for approaches that can guide development of complex (≥ 3 drug) I-O combination treatments by enabling far greater mechanistic understanding of response to drug exposure by components of the authentic tumor microenvironment (TME). Here we show how an approach based on two technologies, the Presage Comparative In Vivo Oncology (CIVO) Platform and the NanoString GeoMx Digital Spatial Profiler (GeoMx DSP), highlights drug synergies as well as mechanisms of resistance to drug exposure in the native and intact TME of cancer patients, providing a path to rapid identification of effective drug combinations. The CIVO platform enables trackable multiplexed intratumoral delivery of microdosed drugs, either as single agents or in combinations, allowing evaluation of the localized tumor response to drug candidates in the TME while capturing tumor heterogeneity and patient diversity. GeoMx DSP is a method for high-plex spatial profiling of mRNAs with rare-cell sensitivity. Combining these technologies in Phase 0 clinical studies in human soft tissue sarcoma patients we evaluated distinct tumor sites microdosed with either nivolumab (anti-PD1), aldesleukin (recombinant IL-2), the combination of nivolumab and aldesleukin, vehicle (no drug), or chemotherapy controls. Using the Nanostring Cancer Transcriptome Atlas we evaluated the effect of drug exposure on expression of over 1,800 genes simultaneously with spatial resolution across individual patient tumors. Synergistic elevation of multiple transcripts was observed at tumor sites exposed to the combination of aldesleukin and nivolumab. This included T-cell specific elevation of granzyme B, a classic biomarker of T-cell activation. Importantly, we show how events such as T-cell activation may be dampened by feedback loops involving immune suppressive responses including, but not limited to, elevation of IDO-1 in non-T-cell components of the TME. Results were observed across multiple patient tumors and were verified by conventional immuno-histochemistry or in situ hybridization. Performing these studies across different patients allows us to explore the inter-individual variation in drug responses. We believe this is an efficient and biologically relevant approach to better understanding feedback loops activated within the authentic TME and ultimately prioritizing drug combinations for clinical development. Citation Format: Jason P. Frazier, Kenneth R. Gundle, Marc Grenley, Gloria Kung, Kimberly Sottero, Kirsten Anderson, Richard Klinghoffer, Jonathan M. Derry. Deep mechanistic profiling of immune oncology (I-O) drug combinations in cancer patients with CIVO® intratumoral microdosing and NanoString GeoMx DSP [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3424.