Targeted Genetics issued patent related to adeno-associated virus (AAV) technology platform

May 30 2005

Targeted Genetics Corporation has announced the issuance of another patent related to the Company's leading adeno-associated virus (AAV) technology platform. U.S. patent #6,897,045, titled "Adeno-Associated Virus Vectors," 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 or regulate a single protein. This approach allows AAV vectors to be used to deliver genes and their 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 vector of choice in the gene-transfer treatment of a wide variety of chronic diseases and for the development of viral vaccines," said Barrie J. Carter, Ph.D., Executive Vice President and Chief Scientific Officer of Targeted Genetics. "To date we have been able to address the size constraint of AAV vectors for our product development programs 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 their 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, 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 further stated, "In the case of this patent, we first recognized that RNA processing provided an interesting mechanism to join together RNA sequences derived from two different AAV vectors. We then engineered vectors in a manner that causes this assembly to join two pieces of RNA that together serve as a template for regulating a single protein. We recognized that this approach is very powerful because it allows us to double the size of the genes and their regulatory sequences 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 genetic diseases and vaccines."

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