First microRNA mimic enters clinic

TBM Austin - Nat. Biotechnol, 2013 - nature.com
TBM Austin
Nat. Biotechnol, 2013nature.com
In April, Austin, Texas–based Mirna Therapeutics began dosing patients with MRX34, the
first microRNA (miRNA) mimic to reach phase 1 studies. Other companies in this emerging
field greeted the news with excitement, yet cautioned that potential off-target side effects and
dosage issues could arise from this entirely novel approach to treating disease. miRNAs are
short (20–25 nucleotides), occur naturally in the cell and help regulate gene expression by
interacting with complementary mRNAs. Because each one modulates tens to hundreds of …
In April, Austin, Texas–based Mirna Therapeutics began dosing patients with MRX34, the first microRNA (miRNA) mimic to reach phase 1 studies. Other companies in this emerging field greeted the news with excitement, yet cautioned that potential off-target side effects and dosage issues could arise from this entirely novel approach to treating disease. miRNAs are short (20–25 nucleotides), occur naturally in the cell and help regulate gene expression by interacting with complementary mRNAs. Because each one modulates tens to hundreds of genes, miRNAs simultaneously control multiple cellular pathways, and when deregulated, contribute to disease.
In cancer, miRNAs are frequently overexpressed or downregulated, and companies are developing therapeutics to correct aberrant expression. With MRX34, which is entering a phase 1 trial in patients with primary liver cancer or metastatic cancer with liver involvement, Mirna’s strategy is to restore lost suppressor function of endogenous miR-34 using a synthetic miRNA mimic. The therapeutic MRX34 directly regulates at least 24 known oncogenes, such as those involved in the cell cycle and proliferation, anti-apoptosis, metastasis, chemoresistance, cancer cell self-renewal and oncogenic transcription.“People have been focused on targeted therapies for many years now, but tumors often find a way to get around the blocks these
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