Phase I/Ib study with INT-1B3, a novel LNP-formulated micro-RNA (miR-193a-3p mimic) therapeutic for patients with advanced solid cancer

TPS2666

Background: MicroRNAs (miR) are naturally-occurring small non-coding RNA molecules involved in the regulation of gene expression and their dysregulation plays a fundamental role in several pathological conditions including cancer. The miR-193a-3p acts as a tumor suppressor and is downregulated in many cancer types. INT-1B3 is a novel lipid-nanoparticle (LNP) formulated 1B3, a 22-nucleotide double stranded chemically-modified miR-193a-3p mimic. INT-1B3 showed significant tumor growth inhibition in a large panel of human and syngeneic tumor models. It directly targets tumor cells and the tumor microenvironment by specific modulation of multiple signaling pathway components. Furthermore, in syngeneic mice models for e.g. TNBC (4T1) and HCC (H22), INT-1B3 was able to modulate the immune tumor microenvironment by turning ‘cold’ tumors into ‘hot’ tumors via upregulation of cytokines (e.g., IL-2 and IFN-g), decreasing immunosuppressive cells/Treg (e.g., CD4+ /LAG3+ and CD3+ /FoxP3+) and triggering cytotoxic CD8+ T cell-mediated long-term memory immune protection against re-challenge with tumor cells. These preclinical results suggest potential clinical benefit in a broad range of cancer indications, and a reduced potential to develop drug resistance due to its multi-targeted mode of action. Methods: This is a 2-part, multi-center, open-label, multiple ascending dose, first-in-human, clinical study to evaluate the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of INT-1B3 in the treatment of patients with advanced solid tumors. The phase 1 part follows a ‘hybrid’ 3+3 study design in ‘all-comer’ cancer patients enrolled and treated in cohorts to define the recommended phase 2 dose (RP2D). Upon completion of the dose escalation phase of the study, 2 expansion cohorts are planned to further confirm the safety, tolerability, and preliminary efficacy of the RP2D of INT-1B3 in patients with hepatocellular carcinoma and triple negative breast cancer. Major eligibility criteria include evaluable disease according to RECIST 1.1 and no more than one prior line of anti-PD-1/PD-L1 therapy. Patients will receive INT-1B3 via 60-min i.v. infusions twice a week in 21-day cycles. The first patient was enrolled on January the 14th 2021. Clinical trial information: NCT04675996.

Transcriptome-wide analysis reveals insight into tumor suppressor functions of 1B3, a novel synthetic miR-193a-3p mimic

Emerging data show that microRNA 193a-3p (miR-193a-3p) has a suppressive role in many cancers and is often downregulated in tumors, as compared to surrounding normal tissues. Therefore, mimics of miR-193a-3p could be used as an attractive therapeutic approach in oncology. To better understand and document the molecular mechanism of action of 1B3, a novel synthetic miRNA-193a-3p mimic, RNA sequencing was performed after transfection of 1B3 in six different human tumor cell lines. Genes differentially expressed (DE) in at least three cell lines were mapped by Ingenuity Pathway Analysis (IPA), and interestingly, these results strongly indicated upregulation of the tumor-suppressive phosphatase and tensin homolog (PTEN) pathway, as well as downregulation of many oncogenic growth factor signaling pathways. Importantly, although unsurprisingly, IPA identified miR-193a-3p as a strong upstream regulator of DE genes in an unbiased manner. Furthermore, biological function analysis pointed to an extensive link of 1B3 with cancer, via expected effects on tumor cell survival, proliferation, migration, and cell death. Our data strongly suggest that miR-193a-3p/1B3 is a potent tumor suppressor agent that targets various key oncogenic pathways across cancer types. Therefore, the introduction of 1B3 into tumor cells may represent a promising strategy for cancer treatment.

Multi-modal effects of 1B3, a novel synthetic miR-193a-3p mimic, support strong potential for therapeutic intervention in oncology

Compelling evidence demonstrates that miR-193a-3p is a tumor suppressor microRNA in many cancer types, and its reduced expression is linked to cancer initiation and progression, metastasis, and therapy resistance. However, its mechanism of action is not consistently described between studies, and often contradicts the pleiotropic role of a microRNA in manipulating several different mRNA targets. We therefore comprehensively investigated miRNA-193a-3p's mode of action in a panel of human cancer cell lines, with a variety of genetic backgrounds, using 1B3, a synthetic microRNA mimic. Interestingly, the exact mechanism through which 1B3 reduced cell proliferation varied between cell lines. 1B3 efficiently reduced target gene expression, leading to reduced cell proliferation/survival, cell cycle arrest, induction of apoptosis, increased cell senescence, DNA damage, and inhibition of migration. SiRNA silencing of 1B3 target mRNAs further highlighted the advantage of the pleiotropic mechanism of 1B3 action, as repression of individual targets did not achieve the same robust effect on cell proliferation in all cell lines. Importantly, a novel lipid nanoparticle-based formulation of 1B3, INT-1B3, demonstrated marked anti-tumor activity as a single agent following systemic administration in tumor-bearing mice. Together, these data strongly support the development of 1B3 as a novel therapeutic agent for treatment of human cancer.

Abstract 4405: Pharmacologic profile of INT-1B3: A novel synthetic microRNA 193a-3p mimic for therapeutic intervention in oncology

MicroRNAs (miRNAs) are a family of small, non-coding RNAs and serve as small snippets of genetic material that regulate gene expression. As a result, miRNAs modulate a wide range of biological processes including; cell cycle control and apoptosis, cell signaling and differentiation, cell adhesion and motility. Thus, it is not surprising that their misregulation is linked to cancer initiation, treatment response, and metastasis. Due to the inherent ability of miRNAs to concurrently target multiple pathways, their therapeutic potential to be used as anti-cancer drugs is attractive. In this study, we are investigating the mode of action and development of a novel synthetic miRNA mimic (INT-1B3) as a therapeutic candidate for substitution and functional restoration of a depleted miRNA in variety of cancers. To identify miRNAs that control the survival of cancer cells, we performed a functional miRNA screening in which a wide range of relevant miRNAs were selected and miR-193a-3p was chosen as the potential candidate for further preclinical characterization. Compelling evidence demonstrate a tumor suppressor function for miR-193a-3p in many cancer types and link its reduced expression with cancer, metastasis and therapy resistance. Consistent with the described role for miR-193a-3p in literature, our cell-based assays conducted in various experimental tumor cell systems demonstrated efficient target engagement leading to reduced cell proliferation/survival, cell cycle arrest and induction of apoptosis, inhibition of cell motility as well as a potential immune-modulatory role (via adenosine-mediated tumor immune evasion). Furthermore, development of a novel lipid nanoparticle-based formulation as an efficient delivery system demonstrated a marked anti-tumor activity of INT-1B3 as single agent following systemic administration in tumor-bearing mice. Robust tumor growth inhibition in these experimental tumor models is correlated and consistent with efficient target engagement in tumor cells and relevant organs. We are currently investigating the in vitro and in vivo effect of INT-1B3 in variety of cancer types including hepatocellular carcinoma, melanoma and triple negative breast cancer. Our data thus far supports an anti-tumor role for INT-1B3 and encourages further preclinical and clinical investigation.

Citation Format: Sanaz Yahyanejad, Thijs de Gunst, Iman Schultz, Harm den Boer, Monica Raimo, Bryony Telford, Rogier Vos, Laurens van Pinxteren, Roel Schaapveld, Michel Janicot. Pharmacologic profile of INT-1B3: A novel synthetic microRNA 193a-3p mimic for therapeutic intervention in oncology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4405.

A functional screen identifies specific microRNAs capable of inhibiting human melanoma cell viability

Malignant melanoma is an aggressive form of skin cancer with poor prognosis. Despite improvements in awareness and prevention of this disease, its incidence is rapidly increasing. MicroRNAs (miRNAs) are a class of small RNA molecules that regulate cellular processes by repressing messenger RNAs (mRNAs) with partially complementary target sites. Several miRNAs have already been shown to attenuate cancer phenotypes, by limiting proliferation, invasiveness, tumor angiogenesis, and stemness. Here, we employed a genome-scale lentiviral human miRNA expression library to systematically survey which miRNAs are able to decrease A375 melanoma cell viability. We highlight the strongest inhibitors of melanoma cell proliferation, including the miR-15/16, miR-141/200a and miR-96/182 families of miRNAs and miR-203. Ectopic expression of these miRNAs resulted in long-term inhibition of melanoma cell expansion, both in vitro and in vivo. We show specifically miR-16, miR-497, miR-96 and miR-182 are efficient effectors when introduced as synthetic miRNAs in several melanoma cell lines. Our study provides a comprehensive interrogation of miRNAs that interfere with melanoma cell proliferation and viability, and offers a selection of miRNAs that are especially promising candidates for application in melanoma therapy.