RXi Demonstrates Robust in vivo Uptake and Significant Silencing Using its Self-Delivering rxRNA™ Compounds Administered to Mouse Retinal Cells

May 4, 2010

WORCESTER, Mass.--(BUSINESS WIRE)--RXi Pharmaceuticals Corporation (Nasdaq: RXII), a biopharmaceutical company pursuing the development and commercialization of proprietary therapeutics based on RNA interference (RNAi), today announced new preclinical data obtained in collaboration with the laboratory of Shalesh Kaushal, M.D., Ph.D., Chairman of the Department of Ophthalmology at The University of Massachusetts Medical School (UMMS). These new data show effective delivery of RXi’s proprietary sd-rxRNA™ to retinal cells in the mouse eye and demonstrate significant target gene silencing in vivo following local administration. In comparison, local injection of a more traditional RNA duplex results in negligible delivery. Lyn Libertine, M.D., Director of Pharmacology at RXi, is presenting these data today at the Association for Research in Vision and Ophthalmology (ARVO) annual meeting taking place in Fort Lauderdale, Florida.

Successful delivery to therapeutically relevant cells of the eye establishes the potential value of sd-rxRNA™ for the treatment of ocular diseases, one of which is age-related macular degeneration (AMD), the leading cause of blindness in Americans over 55 years of age. Together, the wet and dry forms of AMD affect 1.8 million patients in the United States alone, with an additional 7.3 million at risk for the condition.

“RXi’s collaboration with one of the top clinical research ophthalmologists in the U.S. has enabled us to explore the use of sd-rxRNA compounds in the area of retinal disease,” said Noah Beerman, President and Chief Executive Officer of RXi. “We are very encouraged about these recent developments and look forward to continuing to apply our novel therapeutic compounds to disorders of the eye and other areas of significant unmet medical need.”

Next generation sd-rxRNA compounds potentially provide significant advantages over conventional siRNA compounds, and offer many of the properties that will be important for the clinical development of RNAi-based drugs. These advantages include high potency, increased resistance to nucleases and reduction in off-target effects. In addition, sd-rxRNA compounds provide additional unique properties in that they are able to enter cells and tissues with no requirement for any additional delivery vehicle. The enhanced drug-like properties engineered into the sd-rxRNA configuration afford opportunities for use in a broad array of therapeutic indications and make this new class of RNAi molecules a key addition to the rxRNA family of compounds.

Separately, Anastasia Khvorova, Ph.D., Chief Scientific Officer for RXi, will be delivering a keynote address entitled “RNAi: New Promise in Human Therapy” at the Select Biosciences RNAi and miRNA World Congress in Boston, Massachusetts to take place May 5-7.

About RNA Interference (RNAi) and Self-delivering rxRNA™ (sd-rxRNA™)

Regarded as a revolutionary discovery in biology, RNA interference (RNAi) is a naturally occurring mechanism whereby short, double-stranded RNA molecules interfere with the expression of genes in living cells. This mechanism has the potential to be harnessed to "silence" or specifically block the production of disease-causing proteins before they are made. This technology can potentially be used to treat human diseases by "turning-off" genes that lead to disease in the first place. RXi Pharmaceuticals is using RNAi technology to develop RNA-derived molecules targeting disease-causing genes.

Self-delivering rxRNA™(sd-rxRNA™) is a proprietary technology developed at RXi which has the potential to enable the efficient delivery of RNAi compounds without the requirement of an additional delivery vehicle. This novel property has the potential to enable development of sd-rxRNA compounds for therapeutic use in a wide variety of disease indications.

About RXi Pharmaceuticals Corporation

RXi Pharmaceuticals is a discovery-stage biopharmaceutical company pursuing the development and commercialization of proprietary therapeutics based on RNA interference (RNAi) for the treatment of human diseases. RXi has a comprehensive therapeutic platform that includes both novel RNAi compounds and advanced delivery methods that can potentially be applied for local and systemic applications, against targets that may be undruggable by other modalities. RXi uses its proprietary version of RNAi compounds -- rxRNA™ -- that provide an advanced alternative to conventional small interfering RNAs (siRNAs) and define the next generation of RNAi technology. These include rxRNAori™, rxRNAsolo™, and sd-rxRNA™ (or “self delivering” RNA), which are distinct from, and potentially convey significant advantages over, classic siRNAs. RXi Pharmaceuticals believes it is well positioned to compete successfully in the RNAi-based therapeutics market with its accomplished scientific advisors, including Dr. Craig Mello, recipient of the 2006 Nobel Prize for his co-discovery of RNAi; a management team that is experienced in developing RNAi products; and a strong and early, but 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, plan and future development of RXi Pharmaceutical Corporation's products and technologies. These forward-looking statements about future expectations, plans and prospects of the development of RXi Pharmaceutical Corporation's products and technologies involve significant risks, uncertainties and assumptions, including 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 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.

 

CONTACTS:

RXi Pharmaceuticals

Investor Relations

508-929-3615

ir@rxipharma.com

 

or

 

Investors

S. A. Noonan Communications

Susan Noonan

212-966-3650

susan@sanoonan.com

 

or

 

Media

Rx Communications Group

Eric Goldman

917-322-2563

egoldman@rxir.com