RG-101 Interim Analysis Shows 97% Response at 8 Week Follow-Up

- RG-101 Containing Regimen Has Potential to Reduce Harvoni®, Olysio®, or Daklinza™ Rx to 4 Week Duration -
- Regulus to Accelerate Development of RG-101 as Backbone Therapy in HCV -
- Conference Call at 8:30am EST Today -

LA JOLLA, Calif., Feb. 17, 2016 -- Regulus Therapeutics Inc. (RGLS), a biopharmaceutical company leading the discovery and development of innovative medicines targeting microRNAs, today announced interim results from one of the company's ongoing Phase II studies of RG-101 for the treatment of Hepatitis C Virus infection (HCV).  The study was designed to evaluate a shortened, four-week treatment regimen containing a subcutaneous administration of 2 mg/kg of RG-101 at Day 1 and Day 29, in combination with 4 weeks of once/daily approved anti-viral agents Harvoni®, Olysio®, or Daklinza™.  The study enrolled 79 treatment naïve genotype 1 and 4 HCV patients (Harvoni® arm, n=27, Olysio® arm, n=27, Daklinza™ arm, n=25). 

Thirty-eight patients have been evaluated through 8 weeks of follow up. Ninety-seven percent of those patients (37/38) had HCV RNA viral load measurements below the limit of quantification.  To date, RG-101 has been generally well tolerated with the majority of adverse events considered mild or moderate, and with no study discontinuations.  For those patients through 12 weeks of follow-up, 100% remained below the limit of quantification (14/14). The primary endpoint analysis (12 week follow up) for all 79 patients in the study are anticipated to be reported in late Q2 2016.

"These sustained virologic responses demonstrate the potential ability of RG-101 to successfully reduce currently marketed oral treatment regimens to just four weeks, a major clinical breakthrough that the HCV field has not been able to achieve until today and I look forward to future results," said Eric Lawitz, M.D., Vice President, Scientific and Research Development, The Texas Liver Institute, and Clinical Professor of Medicine, University of Texas Health Science Center in San Antonio.  "In addition, I believe this novel approach might allow treating physicians to overcome compliance issues in a wide variety of patient populations."

"The potent antiviral activity and sustained, durable responses observed from this interim analysis, provide evidence that RG-101 may have clinical utility as a potential backbone agent in combination with oral therapies to treat a wide range of HCV patients," said Paul Grint, M.D., President and CEO of Regulus.  "Based on the results announced today, Regulus intends to accelerate development of RG-101 given its promising potential to shorten treatment regimens." 

Conference Call & Webcast Information

Today at 8:30 a.m. EST, Regulus will host a conference call and webcast to discuss these interim results. A live webcast of the call will be available online at www.regulusrx.com.  To access the call, please dial (877) 257-8599 (domestic) or (970) 315-0459 (international) and refer to conference ID 54426274.  To access the telephone replay of the call, dial (855) 859-2056 (domestic) or (404) 537-3406 (international), passcode 54426274. The webcast and telephone replay will be archived on the company's website following the call. 

About Hepatitis C Virus Infection (HCV)

Hepatitis C is a result of a hepatocyte specific infection induced by the virus known as HCV.  Chronic HCV may lead to significant liver disease, including chronic active hepatitis, cirrhosis, and hepatocellular carcinoma. Up to 185 million people are chronically infected with HCV worldwide, and more than 500,000 people die from HCV annually.  The CDC estimates that there are currently approximately 3.5 million persons infected with HCV in the United States.  HCV shows significant genetic variation in worldwide populations due to its frequent rates of mutation and rapid evolution. There are six genotypes of HCV, with several subtypes within each genotype, which vary in prevalence across the different regions of the world. The response to treatment varies from individual to individual underscoring the inadequacy of existing therapies and highlights the need for combination therapies that not only target the virus but endogenous host factors as well, such as microRNA-122. Regulus believes that its miR-122 antagonist, RG-101, may be a useful agent in emerging combination regimens to address difficult-to-treat genotypes and to potentially expand upon the current therapies available to clinicians treating HCV patients.

About RG-101 for HCV

RG-101 is Regulus' wholly-owned, GalNAc-conjugated anti-miR targeting miR-122 for the treatment of HCV. In a completed Phase I human proof-of-concept study, Regulus demonstrated that treatment with a single subcutaneous dose of RG-101 as monotherapy resulted in significant and sustained viral load reductions in all treated HCV patients, including patients with difficult to treat genotypes, various liver fibrosis status and those who have experienced viral relapse after a prior IFN-containing regimen. 

Recently, Regulus presented favorable interim data from an ongoing Phase II study evaluating the combination of RG-101 with multiple approved DAAs positioning RG-101 for both front-line and second-line commercial opportunities. Patients received a single subcutaneous injection of 2 mg/kg of RG-101, followed by 28 days of once daily DAAs Harvoni®, Olysio®, or Daklinza™, followed by an additional subcutaneous injection of 2 mg/kg of RG-101 on Day 29.  Regulus is planning to report primary endpoint analysis at 12 weeks following conclusion of treatment in late Q2 2016.

In the first-quarter of 2016, Regulus, in collaboration with GSK, plans to initiate a Phase II study evaluating the combination of RG-101 and GSK2878175, a non-nucleoside NS5B polymerase inhibitor, in treatment-naïve patients chronically infected with HCV genotypes 1 and 3. Additionally, enrollment is expected to complete in the first half of 2016 in a multi-center, open label, non-randomized Phase I study to compare the safety, tolerability, pharmacokinetics, and pharmacodynamics of 2 mg/kg of RG-101 in subjects with severe renal insufficiency or end-stage renal disease (ESRD) to healthy control subjects, and further explore RG-101 in hepatitis C infected subjects with severe renal insufficiency or ESRD.

About microRNAs

The discovery of microRNAs in humans during the last decade is one of the most exciting scientific breakthroughs in recent history.  microRNAs are small RNA molecules, typically 20 to 25 nucleotides in length, that do not encode proteins but instead regulate gene expression. More than 800 microRNAs have been identified in the human genome, and over two-thirds of all human genes are believed to be regulated by microRNAs.  A single microRNA can regulate entire networks of genes. As such, these molecules are considered master regulators of the human genome.  microRNA expression, or function, has been shown to be significantly altered or dysregulated in many disease states, including oncology, fibrosis, metabolic diseases, immune-inflammatory diseases and HCV. Targeting microRNAs with anti-miRs, chemically modified, single-stranded oligonucleotides, offers a unique approach to treating disease by modulating entire biological pathways and may become a new and major class of drugs with broad therapeutic application.

About Regulus

Regulus Therapeutics Inc. (NASDAQ: RGLS) is a biopharmaceutical company leading the discovery and development of innovative medicines targeting microRNAs.  Regulus has leveraged its oligonucleotide drug discovery and development expertise to develop a well-balanced microRNA therapeutics pipeline complemented by a maturing microMarkers^SM biomarkers platform and a rich intellectual property estate to retain its leadership in the microRNA field.  Regulus is developing RG-101, a GalNAc-conjugated anti-miR targeting microRNA-122 for the treatment of chronic hepatitis C virus infection, and RG-012, an anti-miR targeting microRNA-21 for the treatment of Alport syndrome, a life-threatening kidney disease driven by genetic mutations with no approved therapy.  In addition, RG-125, a GalNAc-conjugated anti-miR targeting microRNA-103/107 for the treatment of NASH in patients with type 2 diabetes/pre-diabetes, has entered Phase I clinical development through its strategic alliance with AstraZeneca.  Regulus is also advancing several programs toward clinical development in orphan disease indications, oncology and fibrosis.  Regulus' commitment to innovation has resulted in multiple peer-reviewed publications in notable scientific journals and has resulted in the formation of strategic alliances with AstraZeneca and Sanofi.  Regulus maintains its corporate headquarters in La Jolla, CA.  For more information, please visit http://www.regulusrx.com.

Forward-Looking Statements

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 development and other activities related to RG-101), 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, 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.