The US Patent and Trademark Office (USPTO) has granted Notice of Allowance for Arrowhead Research Corporation's US Patent Application Number 13/336,028 entitled, “In Vivo Polynucleotide Delivery Conjugates Having Enzyme Sensitive Linkages.” This new IP expands the Dynamic Polyconjugate (DPC) platform, broadly protecting Arrowhead's next generation DPC polymer masking technology.

Using this masking technology, DPCs can be engineered for long circulation times and improved tissue-targeting characteristics. In addition, hepatocyte-targeted DPCs formulated using this new masking technology have shown to be highly potent upon subcutaneous administration. The company has previously reported target gene knockdown of 99 per cent in monkeys after a single subcutaneous injection of 1 mg/kg, with >80 per cent knockdown for three months. Additional data will be reported at upcoming scientific conferences and through peer-reviewed publications.

“This patent protects a new masking chemistry that broadens the reach of DPC-enabled RNAi therapeutics. It enables efficient subcutaneous delivery of siRNA and opens up new therapeutic area targets including oncology,” said Dr Chris Anzalone, president and CEO of Arrowhead. “Arrowhead scientists continue to discover innovative solutions for siRNA delivery and we look forward to providing updates on how these technologies are being deployed to create new drug candidates.”

Arrowhead Research Corporation is a clinical stage targeted therapeutics company with development programmes in oncology, obesity, and chronic hepatitis B virus infection.