RXi Pharmaceuticals Corporation (NASDAQ: RXII), a biotechnology company focused on discovering, developing and commercializing innovative therapies addressing major unmet medical needs using RNA-targeted and immunotherapy technologies, will be presenting data from the NeuVax™ (E75) Phase II adjuvant breast cancer clinical trial at the 2011 annual meeting of The American Society of Clinical Oncology (ASCO) in Chicago. The presentation, entitled “Sequential administration of trastuzumab and a CD8 T-cell-eliciting HER2/neu peptide vaccine in patients with breast cancer compared to trastuzumab alone” (Abstract #564), will be presented at the poster session “Breast Cancer HER2/ER” on Monday, June 6 th from 1:00 – 5:00 PM CDT. In addition, RXi will also be hosting a panel entitled “New Directions in Breast Cancer Therapeutics” on Sunday, June 5th, at 2:00 PM CDT at the Hyatt Regency McCormick Place. The panel presentation will include an update from the NeuVax Phase II clinical trial including the 36-month efficacy data, as well as Phase III plans. The 24 month landmark analysis was first presented at the ASCO Breast Cancer Meeting in October 2010. About NeuVax™ (E75) NeuVax consists of the E75 peptide derived from HER2 combined with the immune adjuvant granulocyte macrophage colony stimulating factor (GM-CSF). Treatment with NeuVax stimulates cytotoxic (CD8+) T cells in a highly specific manner to target cells expressing any level of HER2. NeuVax is given as an intradermal injection once a month for six months, followed by a booster injection once every six months. Based on a successful Phase II trial, which achieved its primary endpoint of disease free survival (DFS), the Food and Drug Administration (FDA) granted NeuVax a Special Protocol Assessment (SPA) for a Phase III clinical trial in the adjuvant setting for women with low-to-intermediate HER2+ status. According to the National Cancer Institute, over 200,000 women in the U.S. are diagnosed with breast cancer annually. 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+ disease 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 (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.