SOURCE: Targeted Genetics

July 11, 2007 12:57 ET

Targeted Genetics Receives Patent on Method to Transfer Recombinant DNAs to Host Cell for Increased Carrying Capacity of AAV Vectors

SEATTLE, WA--(Marketwire - July 11, 2007) - Targeted Genetics Corporation (NASDAQ: TGEN) today announced the issuance of an additional patent related to the Company's leading Adeno-Associated Virus (AAV) technology platform. U.S. patent #7,241,447 titled "Adeno-Associated Virus Vectors and Uses Thereof," was issued to the University of Iowa Research Foundation and is exclusively licensed to Targeted Genetics. The patent covers the use of two AAV vectors to deliver DNA sequences that, once inside a cell, are used to produce a single protein. This approach allows AAV vectors to be used to deliver genes and regulatory sequences that ordinarily would be too large to fit inside a single vector, expanding the potential applications of AAV-based gene delivery.

"We believe that the combined attributes of persistent expression and a good safety profile make AAV vectors the vectors of choice in the gene-transfer treatment of a wide variety of chronic diseases and for the development of vaccines," said Barrie J. Carter, Ph.D., Executive Vice President and Chief Scientific Officer of Targeted Genetics. "We continue to increase the carrying capacity of AAV vectors by utilizing small promoter elements or by modifying DNA sequences to reduce their size without affecting the protein that ultimately is produced. While these approaches can be applied to some genes, the technology covered by this patent significantly expands the potential application of AAV vectors by providing a more flexible method to deliver genes and associated regulatory elements that are larger than the normal carrying capacity of these vectors."

"My laboratory focuses on understanding basic mechanisms of recombinant AAV infection, including how AAV vectors enter cells, how the viral genome gains access to the nucleus and how these genomes are used to make protein," said John F. Engelhardt, Ph.D., Professor and Head of the Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine and Director for the UI Center for Gene Therapy. "Much of what we learn through elucidating these pathways may help to enhance the use of AAV vectors as delivery systems for treating a variety of diseases."

Dr. Engelhardt adds, "In the case of this patent, we first recognized that rAAV vectors can be engineered to contain regulatory sequences in a second rAAV vector that can be used to regulate the expression of proteins in a first rAAV vector. The patent describes two rAAV vectors which when introduced into a host cell become linked providing for cis-acting regulation of the gene product. We recognized that this approach is very powerful because it allows us to double the size of regulatory sequences for genes that one can deliver with AAV vectors. We are excited to be actively working with Targeted Genetics to apply this technology toward the development of novel therapies and vaccines."

About Targeted Genetics

Targeted Genetics Corporation is a biotechnology company committed to the development of innovative targeted molecular therapies for the prevention and treatment of acquired and inherited diseases with significant unmet medical need. Targeted Genetics' proprietary Adeno-Associated Virus (AAV) technology platform allows it to deliver genes that encode proteins to increase gene function or RNAi to decrease or silence gene function. Targeted Genetics' product development efforts target inflammatory arthritis, AIDS prophylaxis, congestive heart failure and Huntington's disease. To learn more about Targeted Genetics, visit Targeted Genetics' website at

Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995:

This release contains forward-looking statements regarding expected use of these proceeds, Targeted Genetics' business strategy, Targeted Genetics' product development and clinical trials, Targeted Genetics' liquidity, revenues from partners and contracts, and ability to meet its ongoing financial obligations and other statements about Targeted Genetics' plans, objectives, intentions and expectations. These statements, involve current expectations, forecasts of future events and other statements that are not historical facts. Inaccurate assumptions and known and unknown risks and uncertainties can affect the accuracy of forward-looking statements. Factors that could affect Targeted Genetics' actual results include, but are not limited to, the risk that Targeted Genetics' revenues or expense do not meet its current expectations, that its clinical trials and product development do not proceed as expected, the possibility that Targeted Genetics decides to use the proceeds from the offering for purposes other than those described above, as well as other risk factors described in "Part I, Item 1A. Risk Factors" in Targeted Genetics' most recent annual report on Form 10-K or "Part II, Item 1A. Risk Factors" in Targeted Genetics' most recent quarterly report on Form 10-Q filed with the Securities and Exchange Commission. You should not rely unduly on these forward-looking statements, which apply only as of the date of this release. Targeted Genetics undertakes no duty to publicly announce or report revisions to these statements as new information becomes available that may change its expectations.