RXi Pharmaceuticals Announces Positive Initial Results in microRNA Therapeutics

WORCESTER, Mass.--(BUSINESS WIRE)--RXi Pharmaceuticals Corporation (Nasdaq: RXII), a recognized leader in RNAi-based therapeutics, announced today that, as part of its collaboration with miRagen Therapeutics, Inc., positive data were generated demonstrating that RXi’s sd-rxRNA™ technology can be used, in vitro, to specifically enhance the activity of a microRNA of high interest to miRagen.

“microRNA therapeutics that mimic native sequences require special approaches for delivery”

The parties have successfully applied RXi’s proprietary sd-rxRNA (self-delivering rxRNA) technology to create microRNA mimics, or artificial copies of microRNAs. In particular, they have demonstrated efficacy in down-regulating a reporter gene whose expression is controlled by the microRNA in cell culture model systems developed by miRagen. Increasing the level of particular microRNAs by using therapeutic mimics may treat certain diseases, including cardiovascular, cancer, inflammatory, fibrotic and metabolic disorders. This data will be presented in a poster at the upcoming Keystone Symposia’s MicroRNAs and Non-Coding RNAs and Cancer meeting February 11-16, 2011 and will be available on RXi’s website after the conference www.rxipharma.com.

"We are very pleased to have obtained positive results from our collaboration with miRagen, a scientific leader in the development of microRNA therapeutics," said Dmitry Samarsky, Ph.D., Vice President of Technology Development at RXi. "Demonstrating that RXi’s sd-rxRNA technology can be applied successfully to convert conventional microRNA mimics into highly functional self-delivering molecules was one important goal of the collaboration and creates the potential to effectively leverage the company’s platform for new and exciting uses in the development of novel therapeutics."

"microRNA therapeutics that mimic native sequences require special approaches for delivery," said William S. Marshall, Ph.D., President and CEO of miRagen Therapeutics. "We are excited that RXi’s self-delivering technology demonstrates this compatibility with microRNA sequences from our portfolio."

About Self-delivering rxRNA (or sd-rxRNA)

RXi’s sd-rxRNA compounds are designed to have drug-like properties, such as high potency, target specificity, serum stability, reduced immune response activation, and efficient cellular uptake. They are hybrid oligonucleotide molecules combining the beneficial properties of both conventional RNAi and antisense technologies. sd-rxRNAs have a single-stranded phosphorothioate region, a short duplex region, and contain a variety of nuclease-stabilizing and lipophilic chemical modifications.

About RXi Pharmaceuticals Corporation

RXi Pharmaceuticals is a recognized leader in RNAi-based therapeutics with a comprehensive platform that includes both RNA interference (RNAi) compounds and delivery technologies. The company is leveraging this broad and integrated platform to build a pipeline of RNAi therapeutic candidates for the treatment of a number of disease areas, including its core focus of developing treatments for dermal anti-scarring and retinal disorders as well as a continued interest in oncology and indications accessible by spinal cord delivery. RXi Pharmaceuticals believes it is well positioned to compete successfully in the RNAi therapeutics market based on the strength of its next generation RNAi platform, experienced management team, accomplished Scientific Advisory Board, including Nobel Laureate, Dr. Craig Mello, and its broad intellectual property position in RNAi chemistry and delivery. www.rxipharma.com

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements about future expectations, plans and future development of RXi Pharmaceutical Corporation’s products, technologies and partnering efforts. These forward-looking statements about future expectations, plans and prospects of the development of RXi Pharmaceutical Corporation’s products and technologies and corporate partnerships involve significant risks, uncertainties and assumptions, including the risk that RXi and third parties may not be able to successfully develop technologies that are the subject of collaborations with such third parties, the risk that the development of our RNAi-based therapeutics may be delayed or may not proceed as planned and we may not be able to complete development of any RNAi-based product, the risk that the FDA approval process may be delayed for any drugs that we develop, risks related to development and commercialization of products by our competitors, risks related to our ability to control the timing and terms of collaborations with third parties and the possibility that other companies or organizations may assert patent rights that prevent us from developing our products. Actual results may differ materially from those RXi Pharmaceuticals Corporation contemplated by these forward-looking statements. RXi Pharmaceuticals Corporation does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date of this release.