RXi Pharmaceuticals to Present Data Demonstrating the Robust Performance of its RNAi Therapeutics Platform at Upcoming Scientific Conference

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 that Dmitry Samarsky, Ph.D., Vice President of Technology Development, will be presenting at the Discovery on Target scientific conference in Boston, MA tomorrow, November 4, 2009. The presentation will not be webcasted.

The presentation will describe RXi's therapeutic platform, including RXi's next generation rxRNA compounds and advanced delivery approaches. The talk will focus on self-delivering rxRNA (sd-rxRNA ) compounds. Dr. Samarsky will present data exemplifying the robust performance of RXi's self-delivering rxRNAs across multiple genes, cell types, target tissues and animal species.

Craig Mello, Ph.D., Chairman of RXi's Scientific Advisory Board and Noble Laureate noted, "The results presented by Dr. Samarsky demonstrate the robustness and potential for broad-based applications of self-delivering rxRNA to multiple therapeutic areas. Scientists are seeking RNAi-delivery solutions to disease tissues, and RXi's results represent some of the most impressive delivery data in the field" .

RXi is leveraging its therapeutic platform for both internal programs and external collaborations and partnerships to create a sustainable pipeline of RNAi based products for unmet medical need.

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 recently developed at RXi which enables the efficient delivery of RNAi compounds without the requirement of an additional delivery vehicle.

About RXi Pharmaceuticals Corporation

RXi Pharmaceuticals is a discovery-stage biopharmaceutical company pursuing the development and potential commercialization of proprietary therapeutics based on RNA interference (RNAi) for the treatment of human diseases. RXi has a comprehensive therapeutic platform that includes both RNAi compounds and delivery methods. RXi uses its own version of RNAi compounds -- rxRNA -- that provide an advanced alternative to conventional small interfering RNAs (siRNAs) and define the next generation of RNAi technology. rxRNA compounds are designed specifically for therapeutic use and contain many of the properties needed to move RNAi based drugs into the clinic. 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 early 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 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.

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