DUET-101

To better understand immune alterations associated with ICB resistance, we assessed blood biomarkers in renal cancer patients classified as responders or non-responders to first line nivolumab/ipilimumab immunotherapy...To assess whether STAT3 inhibition within these cell subsets can promote antitumor immune responses and/or enhance sensitivity to ICB in vivo, we used an original antisense oligonucleotide (ASO) strategy for myeloid-cell selective STAT3 knockdown (CpG-STAT3ASO)...Therapeutic efficacy correlated with activation of dendritic cells (DCs) and M1 macrophages in the tumor microenvironment, reduced percentages of regulatory T cells (Tregs) and the expansion of CD8 T cells in both tumor models. Our study underscores the potential of using myeloid-cell targeted CpG-STAT3 inhibitors for genitourinary cancer therapy to disrupt tolerogenic signaling, restore immune cell activity and sensitivity to immune checkpoint inhibitors and/or T cell-based immunotherapies.

Ourpreliminary in in vitro studies demonstrate CpG-STAT3ASO treatment can reverse patient-derived CD15+ granulocyte immunosuppression onhealthy T cells and restore T cell proliferation...The proposed project willultimately benefit patients with advanced RCC and raise objective response rates. Finally, the proposed project will provide me with trainingunder a research scientist and a clinical scientist treating patients with RCC that will combine the fields of oncology, molecular biology,chemistry, and immunology to prepare me for a career at the forefront of kidney cancer research.

Our results demonstrated that CpG-STAT3dsASO was more effective and significantly better tolerated than single-stranded CpG-STAT3ASO when injected intracranially, without evidence of severe acute neural toxicities within tested dosing... We believe that further development of CpG-STAT3dsASO will pave way to clinical translation of this strategy to immunotherapy of malignant glioma.

Background Combination anti-PD-1 (Nivolumab) and anti-CTLA-4 (Ipilimumab) have improved objective response rates and overall survival in patients with renal cell carcinoma (RCC) over Sunitinib. indicate that novel immunotherapeutic strategy utilizing oligonucleotide-based STAT3 inhibitor (CpG-STAT3ASO) targeting myeloid cells with anti-PD-1 can achieve significant tumor growth inhibition and warrant further investigation into myeloid cell targeting with anti-PD-1 therapy in RCC. Keywords: Nivolumab, Ipilimumab, RCC, STAT3, myeloid cells, immunosuppression

Our results demonstrated that CpG-STAT3dsASO was more effective but also significantly better tolerated than single-stranded CpG-STAT3ASO when injected intracranially, without evidence of severe acute neural toxicities within tested dosing...While, neither of treatments alone was curative, the combination anti-PD1/CpG-STAT3dsASO therapy resulted in complete rejection of orthotopic GL261 tumors in the majority of treated mice (figure 1). Conclusions We believe that further development of CpG-STAT3dsASO will pave way to clinical translation of this strategy to immunotherapy of malignant glioma.

These results were consistent with the maturation and activation of antigen-presenting cells, such as DCs, microglia and macrophages together with increased T cell infiltration into glioma, after the intracranial injections of CpG-STAT3ASOLNA in immunocompetent mice. We believe that our results will pave way to clinical translation of CpG-STAT3ASO for radio-immunotherapy of malignant glioma.

Peritumoral injections of 5 × 10 NSCs loaded ex vivo with CpG-STAT3ASO inhibited subcutaneous tumor growth more effectively than the equivalent amount of oligonucleotide alone. Based on these results, we anticipate that NSCs and NSC-derived exosomes will provide a clinically relevant strategy to improve delivery and safety of oligonucleotide therapeutics for glioma treatment.