SOURCE: Targeted Genetics

April 27, 2008 16:30 ET

Targeted Genetics Announces Data From First Gene Therapy Trial for Leber's Congenital Amaurosis in New England Journal of Medicine

Phase 1/2 Data Shows Improvement in Visual Function

FORT LAUDERDALE, FL and SEATTLE, WA--(Marketwire - April 27, 2008) - Targeted Genetics Corporation (NASDAQ: TGEN) today announced encouraging results from a Phase 1/2 clinical study demonstrating that treatment of three young adults with Leber's congenital amaurosis (LCA) with an Adeno-Associated Virus (AAV) vector containing the RPE 65 coding sequence resulted in improved visual function in one patient. The study, titled "Effect of Gene Therapy on Visual Function in Leber's Congenital Amaurosis," by Bainbridge, et al., conducted in collaboration with University College London and Moorfields Hospital, will appear in the May 22 issue of the New England Journal of Medicine.

This ground-breaking data are also being presented at the Association for Research in Vision and Ophthalmology (ARVO) 2008 Annual Meeting in Fort Lauderdale, Florida. A presentation will be given by Dr. James W. B. Bainbridge, the study surgeon, at 10AM Monday, April 28th, in Room 305 of the Broward County Convention Center. Dr. Bainbridge and the study's Chief Investigator, Dr. Robin R. Ali, will be available for questions after the presentation.

LCA is an inherited retinal degenerative disease characterized by severe impairment of vision from birth and total blindness by the third decade of life. There is no treatment currently available for LCA.

"We are excited to have demonstrated proof-of-principle and early clinical benefit, and will be enrolling additional patients in this study. This approach provides promise for treating LCA caused by RPE65, and eventually, other forms of inherited blindness," stated Professor Robin Ali, University College of London Institute of Ophthalmology and Moorfields Eye Hospital, who led the study. "These findings support further clinical studies of this innovative approach for the treatment of LCA and many different eye conditions."

In the Phase 1/2 study there were no serious adverse events, and in one subject there was a consistent improvement in visual function as measured by visual field tests and improvement in subjective tests of visual mobility.

"The fact that this approach helped one of the patients to have better visual function leading to increased visual mobility is very exciting. Of course, additional studies are needed in order to assess this approach fully, including the expansion of the study to include younger children, but these initial results suggest that AAV-based delivery of genes in the eye can be accomplished," said Barrie J. Carter, Ph.D., executive vice president and chief scientific officer of Targeted Genetics and a co-author of the publication. "We believe gene therapy holds great promise in the creation of a broad new class of innovative medicines and Targeted Genetics is well positioned to participate in this opportunity."

Extensive preclinical testing demonstrated that this AAV-mediated delivery of RPE65 can improve and preserve vision. In the open label, single center, Phase 1/2 clinical study, three young adults between the ages of 17 and 23 years of age with early-onset severe retinal dystrophy, were administered subretinally a single injection of the AAV vector expressing RPE65. In each subject, the eye with the worse acuity was selected as the study eye and the other was used as a control. The subject who showed the objective response probably had less advanced retinal disease at baseline than the other two subjects. The purpose of this study was to determine whether gene therapy for retinal dystrophy caused by RPE 5 mutations was associated with immediately obvious adverse events (primary endpoint) and whether efficacy could be demonstrated in humans (secondary endpoint). Targeted Genetics, a leader in the development and manufacture of AAV-based product candidates, manufactured the vector that is being used in this trial.

These data also were presented today at ARVO by James W. Bainbridge, Wellcome Trust Advanced Fellow at UCL Institute of Ophthalmology and Consultant Ophthalmologist at Moorfields Eye Hospital, at the Association for Research in Vision and Ophthalmology annual meeting in Ft. Lauderdale, Florida.

About Targeted Genetics Corporation

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 the Company's liquidity and financial resources, its ability to fund ongoing and future operations, its business strategy and product development, including statements regarding the data collected in the LCA study, the potential impact of the LCA study on our results of operations and other statements about the Company's 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 actual future events or results include, but are not limited to, payments anticipated by the Company under product development collaborations and contracts, the Company's actual expenses, the Company's ability to raise capital when needed, the timing, nature and results of the Company's clinical trials, potential development of alternative technologies or more effective products by competitors, the Company's ability to obtain and maintain regulatory or institutional approvals, the Company's ability to maintain its listing on the NASDAQ Capital Market and the Company's ability to obtain, maintain and protect its intellectual property, as well as other risk factors described in its filings with the Securities and Exchange Commission (SEC), including in "Item 1A. Risk Factors" in the Company's most recent annual report on Form 10-K for the year ended December 31, 2007 filed with the SEC. You should not rely unduly on these forward-looking statements, which apply only as of the date of this release. The Company undertakes no duty to publicly announce or report revisions to these statements as new information becomes available that may change the Company's expectations.

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