According to the National Cancer Institute, over 200,000 women are diagnosed with breast cancer annually in the US alone in 2010. Of these women, about 75% test positive for Human Epidermal growth factor Receptor 2 (IHC 1+, 2+ or 3+). Only 25% of all breast cancer patients, those with HER2 3+ breast cancer patients are eligible for Herceptin® (trastuzumab; Roche-Genentech) which had revenues of over $5 billion in 2010. NeuVax targets the remaining 50% of HER2 positive patients, those who are HER2+ patients (HER2 1+ and 2+), who achieve remission with current standard of care, but have no available HER2 targeted adjuvant treatment options to maintain their disease free status.About RXI-109 RXi Pharmaceuticals has initiated development of clinical candidate RXI-109, a self-delivering RNAi compound (sd-rxRNA TM) for the reduction of dermal scarring in planned surgeries. RXI-109 is designed to reduce the expression of CTGF (connective tissue growth factor) a critical regulator of several biological pathways involved in fibrosis, including scar formation in the skin. RXi is beginning manufacturing activities with an experienced cGMP oligonucleotide manufacturer to support its IND enabling toxicology program, and is preparing a pre-IND package for submission to the FDA. Pending FDA review, the company intends to use an innovative clinical trial design to study safety and tolerability as well as initial efficacy in its first clinical trial targeted for 2012. About RXi Pharmaceuticals Corporation RXi Pharmaceuticals Corporation is a biotechnology company focused on discovering, developing and commercializing innovative therapies addressing major unmet medical needs using RNA-targeted and immunotherapy technologies. For more information, visit 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 the Apthera acquisition, future expectations, plan and future development of RXi’s and Apthera’s products and technologies. These forward-looking statements about future expectations, plans and prospects of the development of RXi’s and Apthera’s products and technologies involve significant risks, uncertainties and assumptions, including the risk that the development of NeuVax or 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 reduction in our early stage RNAi research and development activities may adversely affect our ability to effectively develop our RNAi technologies, to develop existing or new RNAi product candidates or to enter into or effectively continue collaborations or strategic alliances in this field, 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 contemplated by these forward-looking statements. RXi 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.