TGEN Tecogen Inc

Targeted Genetics Corporation (Nasdaq:TGEN) today announced the issuance of an additional patent related to its adeno-associated virus (AAV) vector manufacturing processes. U.S. patent #6,989,264 is titled, "Methods for generating high titer helper-free preparation of released recombinant AAV vectors." The patent describes AAV purification processes in which recombinant AAV (rAAV) vectors are highly purified utilizing opposing anion and cation chromatography. This approach leads to highly purified AAV vector stocks and is a more cost-effective and scalable purification approach than can be achieved by centrifugation or single chemistry chromatography. Targeted Genetics' growing body of intellectual property related to AAV manufacturing supports several of the Company's product development programs, including its inflammatory arthritis, HIV/AIDS vaccine and congestive heart failure programs. "The issuance of Targeted Genetics' latest patent further strengthens our leadership position in the field of AAV manufacturing and purification," said Barrie J. Carter, Ph.D., Executive Vice President and Chief Scientific Officer of Targeted Genetics. "This patent is important because it supports several enhancements to our proprietary production and purification processes, including improved purification, higher yields, and a more cost-effective process. Notably, this process is readily scalable to meet commercial needs, and eliminates contaminants that may occur at significant levels with other purification methods. The improvements in cost, scalability and purification supported by methods described in this patent are important for the commercialization of our innovative product pipeline." The combined attributes of persistent expression and a good safety profile make AAV vectors the vector of choice for developing gene-transfer treatments for a wide variety of chronic disease and the development of viral vaccines. Most AAV purification procedures are based on density centrifugation or single chemistry column chromatography. Density centrifugation and single chemistry column chromatography yield vector preparations retain significant levels of manufacturing components as contaminants. In the methods described in this patent, AAV vector particles are purified from AAV manufacturing production components by a series of scalable, cost effective chromatography columns utilizing different chemistries. This method can be utilized with any rAAV vector production method including Targeted Genetics' proprietary cell line or hybrid virus technologies, and is expected to support more effective and streamlined production processes. "The addition of this patent further solidifies our leadership position in cell-line based approaches to AAV production," said H. Stewart Parker, President and Chief Executive Officer. "Targeted Genetics' unmatched capabilities in AAV manufacturing encompass both rapid production and highly efficient purification techniques. This manufacturing competence continues to be an important asset for the Company and has been an important factor in our ability to attract strategic partners, enabling us to undertake the largest and most advanced clinical development programs for AAV-based product candidates." 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 www.targetedgenetics.com. Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995: This release contains forward-looking statements regarding our intellectual property, research programs and clinical trials, our manufacturing process, and our product development platforms including AAV vectors and other statements about our plans, objectives, intentions and expectations. In particular, the statements regarding the Company's pipeline and potential application of this patent to any future product candidates 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 its actual results include, but are not limited to, our ability to obtain, maintain and protect our intellectual property, our ability to raise capital when needed, our ability to recruit and enroll suitable trial participants, the timing, nature and results of research and clinical trials, potential development of alternative technologies or more effective processes by competitors, and, our ability to obtain and maintain regulatory or institutional approvals, as well as other risk factors described in the section entitled "Factors Affecting Our Operating Results, Our Business and Our Stock Price" in Targeted Genetics' Quarterly Report on Form 10-Q for the quarter ended September 30, 2005. 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 expectations.