Introgen Therapeutics, Inc. announced that a patent has been awarded titled "Diminishing Viral Gene Expression by Promoter Replacement" by the US Patent and Trademark Office focusing on adenoviral vector development, which is the most commercially important type of viral vector used in the field of gene therapy. The patent, US Patent No 7,244,617, is one of numerous patents, pending or issued, that Introgen has licensed exclusively from The University of Texas System M. D. Anderson Cancer Center.
David L. Parker, Ph.D, J.D., Introgen's senior vice president of Intellectual Property, commented, "This patent is a significant addition to Introgen's intellectual property portfolio in that it covers viral vectors with genetic modifications that will permit researchers to easily control the replication of such vectors by, for example, supplying an inducing factor, which can prevent unwanted vector replication in patients."
The claims of this patent also cover the deletion of multiple viral genes within a vector. Deleting multiple viral genes allows for the insertion of numerous or large therapeutic genes, including tumour suppressor genes. Alternatively, the deletion of the multiple viral genes from the vector allows for one or two large therapeutic genes. This patent also covers the adenoviral vector's use with pro-apoptotic genes, currently designed to induce cell death in the target cell, one of the desired outcomes in treating cancer.
Adenoviruses are clinically important viruses used to deliver therapeutic or diagnostic genes to cells and have been used in hundreds of thousands of patients in government, industry and academia for vaccine and therapy programs. Adenoviruses can be genetically altered so that they are unable to replicate in humans and they do not mix with a patient's DNA. Adenoviruses have important properties that lend themselves readily to commercial scale manufacturing. Introgen's own adenoviral vector based therapies include ADVEXIN p53 therapy and INGN 241 mda-7 therapy. There currently are hundreds of development programs around the world for adenoviral-based therapies, including oncolytics, gene and protein delivery for cancer, cardiovascular, ophthalmologic, siRNA, and numerous other direct therapies, as well as forming the basis for the next generation of vaccines. All of these technologies will potentially benefit from the technology covered by this patent.
ADVEXIN p53 therapy is a targeted molecular therapy with broad applicability in a wide range of tumour types and clinical settings because it targets one of the most fundamental and common molecular defects, abnormal p53 tumour suppressor function, associated with cancer initiation, progression and treatment resistance. ADVEXIN has demonstrated increased survival and tumour growth control in recurrent head and neck cancer patients. ADVEXIN has demonstrated clinical activity in a number of solid tumour types in multiple phase 1, 2 and 3 clinical trials conducted worldwide.
INGN 241 is being tested in a Phase 2 clinical trial for patients suffering from advanced melanoma and in a Phase 3 clinical trial in combination with radiation therapy in solid tumours. The mda-7 gene is the active component of INGN 241 and was discovered in the laboratory of Dr. Paul B. Fisher, professor of clinical pathology at Columbia University. Introgen holds an exclusive worldwide sublicense to the Columbia University rights for all gene therapy applications from GlaxoSmithKline.