Marina Biotech, Inc., a leading nucleic acid-based drug discovery and development company, announced that the US Patent and Trademark Office (USPTO) has issued a Notice of Allowance for patent application US 11/955,207 with claims that cover a library of over 1x10(15) novel peptides. The patent application is part of the company's proprietary Trp Cage Library patent portfolio. This allowance strengthens the company's nucleic acid-peptide drug delivery platform, and further expands the company's patent protection for its comprehensive set of nucleic acid delivery technologies, which also include DiLA2, SMARTICLES and the tkRNAi system.

"A primary advantage of this patented peptide library is the ability to rapidly screen and identify novel peptides that exhibit cell specific targeting characteristics for directed delivery of nucleic acid therapeutics," said Barry Polisky, Ph.D., chief scientific officer of Marina Biotech. "Delivery remains a significant challenge in the nucleic acid therapeutic space, and peptides with high affinity and specificity are expected to be a fundamental component to developing delivery approaches to a wide spectrum of tissues and cell types. In addition, the library may also be exploited to screen for peptides that function as specific antagonists, agonists or generally exhibit drug like properties."

The company's proprietary Trp Cage Phage Display Library (J Biol Chem. 2007 282(13):9813) is the subject of issued patents, US patent 7,329,725; US patent 7,704,953 and US patent 7,772,189. The Trp Cage motif is highly structured allowing for the identification of peptides with high binding affinity for specific cell or tissue types, and avoids the limitations of low affinity and specificity often associated with linear peptide libraries. This technology is directly applicable to the company's DiLA2 and SMARTICLES delivery platforms as peptides are readily conjugated to the components of these delivery platforms. Peptides capable of directed delivery are expected to further improve the delivery efficiency of the company's UNA and CRN substituted nucleic acid constructs, which have demonstrated in vivo activity and efficacy against targets in both normal/healthy and disease models, respectively.

A Notice of Allowance confirms the substantive examination of a patent application and will result in a final issuance of a US patent after an administrative process is completed.

Marina Biotech is a biotechnology company, focused on the development and commercialization of RNA interference- (RNAi) and RNA-based therapeutics. The Marina Biotech pipeline currently includes a clinical programme in Familial Adenomatous Polyposis (a precancerous syndrome) and two preclinical programmes -- in bladder cancer and malignant ascites.