Anastasiadou, E., Seto, A. G., Beatty, X., Hermreck, M., Gilles, M. E., Stroopinsky, D., Pinter-Brown, L. C., Pestano, L., Marchese, C., Avigan, D., Trivedi, P., Escolar, D. M., Jackson, A. L., & Slack, F. J. (2021). Cobomarsen, an Oligonucleotide Inhibitor of miR-155, Slows DLBCL Tumor Cell Growth In Vitro and In Vivo. Clinical cancer research : an official journal of the American Association for Cancer Research, 27(4), 1139–1149. https://doi.org/10.1158/1078-0432.CCR-20-3139
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.