GBM is a highly malignant form of brain tumor.  miR-10b is highly expressed in all GBM molecular subtypes, and its expression in normal brain cells is nearly undetectable.  Its cells reproduce quickly and are nourished by a large network of blood vessels, fueling rapid growth and making it one of the most aggressive forms of brain cancer. Because of its aggressiveness, GBM is categorized as a high grade glioma (HGG).  GBM is one of the most common forms of HGG, with new diagnoses estimated to be approximately 12,500 in 2018 in the United States. It accounts for about half of all brain and central nervous system cancers and is reported to have a five-year survival rate of approximately five percent.

RGLS5579 is a novel oligonucleotide designed to inhibit miR-10b.  Preclinical studies with RGLS5579 have demonstrated direct anti-tumor effects in vitro and in vivo.  RGLS5579 was selected from a library of over 200 anti-miRs targeting miR-10b based on its potency, selectivity and safety profile.  In an orthotopic mouse model in which human GMB tumor cells were implanted into the brains of immunocompromised mice, RGLS5579 increased median survival as a monotherapy, and markedly extended median survival time in combination with TMZ. 

Regulus Therapeutics Inc. (NASDAQ:RGLS) is a biopharmaceutical company focused on the discovery and development of innovative medicines targeting microRNAs.  Regulus has leveraged its oligonucleotide drug discovery and development expertise to develop a pipeline complemented by a rich intellectual property estate in the microRNA field.  Regulus maintains its corporate headquarters in La Jolla, CA.  For more information, please visit http://www.regulusrx.com.

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including statements associated with the expected ability of Regulus to undertake certain activities and accomplish certain goals (including with respect to the advancement of RGLS5579 for the treatment of glioblastoma multiforme), the projected timeline of clinical development activities, , and expectations regarding future therapeutic and commercial potential of Regulus' business plans, technologies and intellectual property related to microRNA therapeutics and biomarkers being discovered and developed by Regulus.  Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "intends," "will," "goal," "potential" and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Regulus' current expectations and involve assumptions that may never materialize or may prove to be incorrect.  Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation and risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such drugs.  These and other risks concerning Regulus' financial position and programs are described in additional detail in Regulus filings with the Securities and Exchange Commission.  All forward-looking statements contained in this press release speak only as of the date on which they were made. Regulus undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.