Press Release

BOTHELL, WA, Sep 19, 2011 (MARKETWIRE via COMTEX) --

AVI BioPharma, Inc. (NASDAQ: AVII), a developer of RNA-based therapeutics, today announced that the Company's influenza program, including its lead therapeutic candidate AVI-7100, will be featured in three presentations at the 51st Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) Annual Meeting taking place September 17 - 20 in Chicago, IL.

Peter Sazani, Ph.D., Executive Director of Preclinical Development at AVI, will deliver a poster presentation titled "Toxicity and Toxicokinetic Evaluation of AVI-7100, Targeted to a Highly Conserved Region of Influenza A Virus" at 11:15 a.m. CDT on Monday, September 19. The presentation will be given during poster session 180, called "New Agents Active Against Viral and Viral-Associated Infections."

Patrick Iversen, Ph.D., Senior Vice President of Research and Innovation at AVI, will deliver a poster presentation titled "AVI-7100 is Effective in Oseltamivir Resistant H1N1 Infected Ferrets" at 11:15 a.m. CDT on Monday, September 19, during poster session 180.

Dr. Iversen will also deliver a poster presentation titled "AVI-7100 Prevents Transmission from Oseltamivir Resistant H1N1 Viral Infected to Naive Ferrets" at 11:15 a.m. CDT on Monday, September 19, during poster session 180.

All presentations will be posted on the AVI BioPharma website in the "Events & Presentations" section after their respective sessions are completed.

About AVI-7100 AVI-7100 is AVI's lead therapeutic candidate for the treatment of influenza, currently being investigated in a Phase 1 clinical study. AVI-7100 targets a well-conserved region of the influenza A virus, affording it the potential to act as a broad-spectrum treatment for multiple influenza strains, including Tamiflu-resistant flu strains. Seasonal influenza (H3N2) and the more recently emergent swine origin influenza virus (SOIV), H1N1, are both caused by the influenza A virus. AVI-7100 employs the Company's patented PMOplus(TM) technology that selectively introduces positive charges to a phosphorodiamidate morpholino oligomer (PMO) backbone to improve selective interaction between the drug and its target. AVI-7100 was preclinically developed and identified as the lead candidate with support from the U.S. Department of Defense's Joint Project Manager Transformational Medical Technologies (JPM-TMT) under contract HDTRA1-09-C-0046.

Preclinical studies funded under JPM-TMT contract HDTRA1-10-C-0079 demonstrated that AVI-7100 improved clinical symptoms and reduced viral titers in animal models infected with pandemic H1N1 or H3N2 viruses, and had statistically significant activity as compared to saline and Tamiflu controls.

About AVI BioPharma AVI BioPharma is focused on the discovery and development of novel RNA-based therapeutics for rare and infectious diseases, as well as other select disease targets. Applying pioneering technologies developed and optimized by AVI, the Company is able to target a broad range of diseases and disorders through distinct RNA-based mechanisms of action. Unlike other RNA-based approaches, AVI's technologies can be used to directly target both messenger RNA (mRNA) and precursor messenger RNA (pre-mRNA) to either down-regulate (inhibit) or up-regulate (promote) the expression of targeted genes or proteins. By leveraging its highly differentiated RNA-based technology platform, AVI has built a pipeline of potentially transformative therapeutic agents, including eteplirsen, which is in clinical development for the treatment of Duchenne muscular dystrophy, and multiple drug candidates that are in clinical development for the treatment of infectious diseases. For more information, visit www.avibio.com.

Forward-Looking Statements and Information In order to provide AVI's investors with an understanding of its current results and future prospects, this press release contains statements that are forward-looking. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "will," "intends," "potential," "possible" and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements about the development of AVI's product candidates, their efficacy, potency and utility in the treatment of rare and infectious diseases and their potential to treat a broad number of human diseases.

These forward-looking statements involve risks and uncertainties, many of which are beyond AVI's control. Known risk factors include, among others: clinical trials may not demonstrate safety and efficacy of any of AVI's drug candidates and/or AVI's antisense-based technology platform; and any of AVI's drug candidates may fail in development, may not receive required regulatory approvals, or be delayed to a point where they do not become commercially viable.

Any of the foregoing risks could materially and adversely affect AVI's business, results of operations and the trading price of AVI's common stock. For a detailed description of risks and uncertainties AVI faces, you are encouraged to review the official corporate documents filed with the Securities and Exchange Commission. AVI does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof.

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995: The statements that are not historical facts contained in this release are forward-looking statements that involve risks and uncertainties, including, but not limited to, the results of research and development efforts, the results of preclinical and clinical testing, the effect of regulation by the FDA and other agencies, the impact of competitive products, product development, commercialization and technological difficulties, and other risks detailed in the company's Securities and Exchange Commission filings.

AVI Media and Investor Contact:
Erin Cox
Manager, Corporate Communications and Investor Relations
425.354.5140
Email Contact

AVI Media Contact:
David Schull
Russo Partners
858.717.2310 or 212.845.4271
Email Contact

SOURCE: AVI BioPharma, Inc.

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