SOURCE: Targeted Genetics Corporation

October 25, 2006 07:30 ET

Targeted Genetics Receives Patent for Enhanced Core Technology Including Expressed RNA

SEATTLE, WA -- (MARKET WIRE) -- October 25, 2006 -- Targeted Genetics Corporation (NASDAQ: TGEN) today announced the issuance of an additional patent related to its adeno-associated virus (AAV) vector technology that describes delivery of genes or delivery of small therapeutic genetic constructs or small therapeutic genetic constructs including therapeutic RNA molecules such as RNAi. U.S. patent #7,125,717 entitled "Metabolically Activated Recombinant Viral Vectors and Methods for Their Preparation and Use" describes the use of AAV vectors that are more efficient for expression of therapeutic genetic constructs.

Single stranded Deoxyribonucleic acid (DNA) vectors like AAV require conversion to a double-stranded DNA form in order for the therapeutic gene of interest to be expressed. The AAV virus DNA is about 4.7 Kb in size. However, a significant number of either genes used in gene therapy as well as genetic constructs such as expressed RNA or RNAi are approximately half this size or less. This patent is the first to demonstrate that AAV vectors containing genetic sequences that are roughly half the size of an AAV payload can form intrastrand based pairing, rapidly converting the therapeutic construct to an expressible form. This results in a more rapid and efficient expression of the therapeutic genetic construct, and has the potential for increased benefit in treating or preventing disease.

"The issuance of Targeted Genetics' latest patent adds to a portfolio of intellectual property that enhances the utility of AAV vectors in two important ways: first, for expressing therapeutic genes in order to add back necessary proteins to prevent or correct a disease state, and second, for expressing therapeutic RNA molecules, such as RNAi, which can silence or block the expression of abnormal proteins associated with other disease states. Abnormal production of proteins is the cause of many human diseases; and RNAi naturally occurs within cells to regulate gene expression, thus blocking or silencing the production of specific disease causing proteins. The use of AAV Vectors described in this patent to express these specific double stranded therapeutic RNAs, such as RNAi, may specifically block the expression of these abnormal proteins associated with disease," said Barrie J. Carter, Ph.D., executive vice president and chief scientific officer of Targeted Genetics Corporation and inventor on the patent.

"Targeted Genetics has over ten years of expertise in the development of AAV vectors to treat a broad array of diseases and using AAV vectors to treat diseases where delivery and efficient expression of a therapeutic gene of interest has long been a focus of the company. Given the recent advances and excitement in the field of developing a new class of RNA therapeutics, such as RNAi, that block the expression of abnormal proteins, development of the use of vectors described in this issued patent is a natural extension of our work as a company and broadens our class of potential therapeutic targets," said H. Stewart Parker, president and chief executive officer of Targeted Genetics. "The key is that utilizing these vectors may allow us to treat disease by essentially turning on or turning off gene expression associated with disease states."

Targeted Genetics was the first to bring AAV vectors into clinical trials. AAV is a naturally occurring virus that is not associated with any disease in humans. AAV vectors can efficiently deliver genetic information to numerous cell types and can be engineered to carry a variety of DNA sequences. These vectors are highly stable, persist in cells for extended periods of time, and carry an extremely low frequency of integration into host-cell DNA.

About Targeted Genetics

Targeted Genetics Corporation is a biotechnology company committed to the development and commercialization of innovative targeted molecular therapies for the prevention and treatment of inflammatory arthritis, HIV/AIDS and other acquired and inherited diseases with significant unmet medical need. Targeted Genetics uses its considerable knowledge and capabilities in the development and manufacturing of gene delivery technologies to advance a diverse product development pipeline. Its product development efforts target inflammatory arthritis, HIV/AIDS, congestive heart failure, Huntington's disease, and hyperlipidemia. To learn more about Targeted Genetics, visit its website at

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

This release contains forward-looking statements regarding our patent portfolio, our business strategy, our product development and other statements about our plans, objectives, intentions and expectations. In particular, the statements regarding the Company's future plans are forward-looking statements. 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 our actual results include, but are not limited to, our ability to raise capital when needed, our ability to obtain, maintain and protect our intellectual property, the timing, enrollment of patients, nature and results of our clinical trials, potential development of alternative technologies or more effective products by competitors, and our ability to obtain and maintain regulatory or institutional approvals, as well as other risk factors described in Item 1A. Risk Factors in our report on Form 10-K for the year ended December 31, 2005, and updated in Item 1A. Risk Factors in our subsequent reports on Form 10-Q. You should not rely unduly on these forward-looking statements, which apply only as of the date of this release. We undertake no duty to publicly announce or report revisions to these statements as new information becomes available that may change our expectations.

Contact Information

  • Investor and Media Contact:
    Stacie D. Byars
    Director, Communications
    Targeted Genetics Corporation
    (206) 521-7392