miR-155, a microRNA associated with poor prognosis in lymphoma and leukaemia, has been implicated in the progression of mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma (CTCL). In this study, we developed and tested cobomarsen (MRG-106), a locked nucleic acid-modified oligonucleotide inhibitor of miR-155. In MF and human lymphotropic virus type 1 (HTLV-1+) CTCL cell lines in vitro, inhibition of miR-155 with cobomarsen de-repressed direct miR-155 targets, decreased expression of multiple gene pathways associated with cell survival, reduced survival signalling, decreased cell proliferation and activated apoptosis. We identified a set of genes that are significantly regulated by cobomarsen, including direct and downstream targets of miR-155. Using clinical biopsies from MF patients, we demonstrated that expression of these pharmacodynamic biomarkers is dysregulated in MF and associated with miR-155 expression level and MF lesion severity. Further, we demonstrated that miR-155 simultaneously regulates multiple parallel survival pathways (including JAK/STAT, MAPK/ERK and PI3K/AKT) previously associated with the pathogenesis of MF, and that these survival pathways are inhibited by cobomarsen in vitro. A first-in-human phase 1 clinical trial of cobomarsen in patients with CTCL is currently underway, in which the panel of proposed biomarkers will be leveraged to assess pharmacodynamic response to cobomarsen therapy.
Purpose: miRNA-155 is an oncogenic miRNA highly expressed in B-cell malignancies, particularly in the non–germinal center B-cell or activated B-cell subtype of diffuse large B-cell lymphoma (ABC-DLBCL), where it is considered a potential diagnostic and prognostic biomarker. Thus, miR-155 inhibition represents an important therapeutic strategy for B-cell lymphomas. In this study, we tested the efficacy and pharmacodynamic activity of an oligonucleotide inhibitor of miR-155, cobomarsen, in ABC-DLBCL cell lines and in corresponding xenograft mouse models. In addition, we assessed the therapeutic efficacy and safety of cobomarsen in a patient diagnosed with aggressive ABC-DLBCL. Experimental Design: Preclinical studies included the delivery of cobomarsen to highly miR-155–expressing ABC-DLBCL cell lines to assess any phenotypic changes, as well as intravenous injections of cobomarsen in NSG mice carrying ABC-DLBCL xenografts, to study tumor growth and pharmacodynamics of the compound over time. To begin to test its safety and therapeutic efficacy, a patient was recruited who underwent five cycles of cobomarsen treatment. Results: Cobomarsen decreased cell proliferation and induced apoptosis in ABC-DLBCL cell lines. Intravenous administration of cobomarsen in a xenograft NSG mouse model of ABC-DLBCL reduced tumor volume, triggered apoptosis, and derepressed direct miR-155 target genes. Finally, the compound reduced and stabilized tumor growth without any toxic effects for the patient. Conclusions: Our findings support the potential therapeutic application of cobomarsen in ABC-DLBCL and other types of lymphoma with elevated miR-155 expression.
Treatment-resistant hematological malignancies remain an area of high unmet need and novel therapeutic approaches will be required. microRNAs are small (~ 22 nt) non-coding RNAs that act as negative regulators of gene expression. These small RNAs impact expression of a substantial fraction of the genome, and have powerful effects on cellular phenotypes and physiological processes. miR-155-5p is a well-described oncomiR associated with poor prognosis in multiple malignancies, particularly lymphoma and leukemia. Cutaneous T-cell lymphoma (CTCL) is a rare hematological malignancy with limited treatment options and a strong mechanistic link to increased miR-155-5p. Because of the accessibility of cutaneous lesions, CTCL provides a unique opportunity to determine if inhibition of miR-155-5p has therapeutic potential in lymphomas associated with elevated miR-155-5p. We optimized a LNA-modified oligonucleotide inhibitor of miR-155-5p, MRG-106, based on the ability to de-repress canonical miR-155-5p targets in multiple cell types in vitro. In mycosis fungoides (MF) cell lines, MRG-106 does not require additional formulation to achieve maximum pharmacodynamic efficacy. Inhibition of miR-155-5p resulted in transcriptome changes consistent with miR-155-5p target gene modulation, reduction in cell proliferation, and activation of the programmed cell death pathway. The gene expression and phenotypic effects were inhibitor dose-dependent and sequence-specific. Based on an informatics approach for the expression profiling of MF cell lines treated with MRG-106, a set of 600 genes was identified to represent the translational pharmacodynamic biomarker signature, both direct and downstream of miR-155-5p. GLP preclinical safety studies have been completed in rats and non-human primates, demonstrating an acceptable safety profile for MRG-106. We plan to initiate a 4-week first-in-human clinical trial in CTCL (MF) patients. The trial design is two-part, with Part A testing the effect of direct intra-tumoral injection of MRG-106 into plaque and nodular skin lesions, and Part B testing the effect of systemic (subcutaneous) administration of higher doses of MRG-106. The primary objective of Part A is to profile the pharmacodynamic effect of MRG-106 on the miR-155-5p gene expression signature, establishing a PK/PD model to guide future development. The primary objective of Part B is to establish the safety, tolerability, PK and skin deposition of MRG-106 after systemic delivery. Exploratory objectives include measures for clinical response, immune system effects, and biomarker validation. Disclosures Seto: miRagen Therapeutics: Employment, Equity Ownership. Beatty:miRagen Therapeutics: Employment, Equity Ownership. Pestano:miRagen Therapeutics: Employment, Equity Ownership. Dickinson:miRagen Therapeutics: Employment, Equity Ownership. Warren:miRagen Therapeutics: Consultancy. Rodman:miRagen Therapeutics: Employment, Equity Ownership. Jackson:miRagen Therapeutics: Employment, Equity Ownership.
<p>Supplementary table S1</p>
<p>Supplementary figure S2</p>
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.