Press Release

For Immediate Release

PORTLAND, OR — June 26, 2009 — AVI BioPharma, Inc. (NASDAQ: AVII), a developer of RNA-based drugs, today announced that immediately following the close of the U.S. markets today it will join the broad-market Russell 3000^® Index following Russell Investments’ annual reconstitution of its comprehensive set of U.S. and global equity indexes.

The annual reconstitution of Russell’s U.S. indexes captures the 4,000 largest U.S. stocks as of the end of May, ranking them by total market capitalization. Membership in the Russell 3000, which remains in place for one year, means automatic inclusion in the large-cap Russell 1000 Index or small-cap Russell 2000 Index as well as the appropriate growth and value style indexes. Russell determines membership for its equity indexes primarily by objective, market-capitalization rankings and style attributes. The Russell 3000 also serves as the U.S. component to the Russell Global Index, which Russell launched in 2007.

Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for both passive and active investment strategies.

About AVI BioPharma

AVI BioPharma is focused on the discovery and development of RNA–based drugs utilizing proprietary derivatives of its antisense chemistry (morpholino-modified phosphorodiamidate oligomers or PMOs) that can be applied to a wide range of diseases and genetic disorders through several distinct mechanisms of action. Unlike other RNA therapeutic approaches, AVI’s antisense technology has been used to directly target both messenger RNA (mRNA) and its precursor (pre-mRNA), allowing for both up- and down-regulation of targeted genes and proteins. AVI’s RNA–based drug programs are being evaluated for the treatment of Duchenne muscular dystrophy as well as for the treatment of cardiovascular restenosis through our partner Global Therapeutics, a Cook Group Company. AVI’s antiviral programs have demonstrated promising outcomes in Ebola Zaire and Marburg Musoke virus infections and may prove applicable to other viral targets such as HCV or Dengue viruses. For more information, visit www.avibio.com.