cobomarsen (MRG-106)

Approaches include targeting viral transcripts directly (e.g., siRNAs against HBV surface antigen) or host factors critical for viral replication (e.g., anti-miR-122 miravirsen for HCV)...These include TargomiR (a miR-16 mimic for mesothelioma), cobomarsen (an anti-miR-155 for lymphomas), and MRX34 (a miR-34a mimic for various solid tumours)...Despite promising preclinical results, clinical translation has been hampered by issues like insufficient delivery efficiency to human tumours, toxicity, and the complex, interconnected regulatory networks of miRNAs, which can lead to unpredictable off-target effects. While RNA therapeutics hold immense promise, overcoming delivery barriers and enhancing understanding of RNA regulatory networks are essential for future success.

To address this, we developed a TME-responsive polymeric micelle co-delivering alpelisib (a pan-PI3K inhibitor) and cobomarsen (a miR-155-5p inhibitor) for targeted therapy. This dual-targeting strategy effectively suppressed PIK3CA-mutated tumor growth and epithelial-mesenchymal transition. These findings reveal the role of MDSC-driven metastatic potential via the exosomal miR-155-5p/SIRT1 axis in HR + breast cancer and present a novel nanotherapeutic approach for precision intervention.

Considering clinical trials targeting PGE2 production largely have focused on the inhibition of Cox1 or Cox2 that showed cardiac toxicity, our data suggest an alternative way for suppressing PGE2 production via the inhibition of miR-155. As the antagomiR of miR-155 (MRG-106) underwent a phase-1 clinical trial, its effect should be considered and analyzed in prostaglandin metabolism in tumor.

Our findings support the potential therapeutic application of cobomarsen in ABC-DLBCL and other types of lymphoma with elevated miR-155 expression.