Arrowhead Research Corporation (NASDAQ: ARWR), a targeted therapeutics company, today announced that it entered into an agreement with Merck, through a subsidiary, to undertake an evaluation of a novel proprietary therapeutic monoclonal antibody candidate derived from Arrowhead’s human-derived peptide targeting and discovery program. Arrowhead acquired this program through its purchase of Alvos Therapeutics in April 2012. Merck will bear the costs involved in evaluating the candidate. “We are excited to be working with Merck as they evaluate this antibody candidate,” said Dr. Chris Anzalone, President and Chief Executive Officer of Arrowhead. “We believe that our human-derived library of targeting peptides and novel receptors is the world’s largest and can be used with many classes of drugs across multiple indications to enhance efficacy and decrease side effects.” Arrowhead’s target discovery and delivery platform consists of a large library of unique human-derived peptide sequences selected for their ability to bind cell surface targets and rapidly internalize within cells of more than 30 distinct tissues and multiple tumor types. The discovery process, which involves screening directly in human patients under strict ethical guidelines, has identified novel receptor targets as well as novel binding sites for validated targets. Additional antibody and peptide-based targeting programs for oncology and other therapeutic areas are currently being identified and assessed for internal development or partnering. About Arrowhead Research Corporation Arrowhead Research Corporation is a clinical stage targeted therapeutics company with development programs in oncology, obesity, and infectious disease. The company leverages its platform technologies to design and develop peptide-drug conjugates (PDCs) which specifically home to cell types of interest while sparing off-target tissues, creates targeted drugs based on the gene silencing RNA interference (RNAi) mechanism, and works with partners to create improved versions of traditional small molecule drugs. For more information please visit http://www.arrowheadresearch.com, or follow us on Twitter @ArrowRes. To be added to the Company's email list to receive news directly, please send an email to email@example.com Safe Harbor Statement under the Private Securities Litigation Reform Act: This news release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. These statements are based upon our current expectations and speak only as of the date hereof. Our actual results may differ materially and adversely from those expressed in any forward-looking statements as a result of various factors and uncertainties, including our ability to finance our operations, the future success of our scientific studies, our ability to successfully develop drug candidates, the timing for starting and completing clinical trials, rapid technological change in our markets, and the enforcement of our intellectual property rights. Arrowhead Research Corporation's most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q discuss some of the important risk factors that may affect our business, results of operations and financial condition. We assume no obligation to update or revise forward-looking statements to reflect new events or circumstances.