RXi Pharmaceuticals Completes Apthera Acquisition

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, today announced the completion of its previously announced acquisition of Apthera, Inc.

The acquisition provides RXi with a late stage product candidate, NeuVax™, a peptide-based immunotherapy for low-to-intermediate HER2+ breast cancer, patients who are not eligible for Herceptin® RXi has targeted NeuVax to enter Phase III clinical trials in the first half of 2012. The Company’s first self-delivering RNAi product, RXI-109 for anti-scarring in planned surgeries, remains on track for an investigational new drug (IND) application filing this year.

Under the terms of the acquisition agreement, Apthera stockholders will initially receive approximately 4.8 million shares of RXi’s common stock. Apthera’s stockholders will also be entitled to contingent payments based on the achievement of certain development and commercial milestones relating to Apthera’s NeuVax ™ product candidate.

“NeuVax and RXI-109 significantly advance RXi into a product development company with novel therapeutics addressing large unmet medical needs,” said Mark J. Ahn, PhD, President and Chief Executive Officer of RXi Pharmaceuticals. “We believe we have the people, pipeline and resources to realize the promise of our innovative products for patients and shareholders.”

An audiocast presentation including an RXi corporate overview of the Apthera acquisition and cancer immunotherapy treatment featuring Dr. Mark Ahn and NeuVax developer Dr. George Peoples will be available from the “Investor Relations” section of the Company's website, www.rxipharma.com.

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 adjuvant therapy of women with low-to-intermediate HER2+ status.