RXi Pharmaceuticals Corporation, a recognized leader in RNAi-based therapeutics, announced that, as part of its collaboration with miRagen Therapeutics, Inc., positive data were generated demonstrating that RXi's sd-rxRNA technology can be used, in vitro, to specifically enhance the activity of a microRNA of high interest to miRagen.

The parties have successfully applied RXi's proprietary sd-rxRNA (self-delivering rxRNA) technology to create microRNA mimics, or artificial copies of microRNAs. In particular, they have demonstrated efficacy in down-regulating a reporter gene whose expression is controlled by the microRNA in cell culture model systems developed by miRagen.

Increasing the level of particular microRNAs by using therapeutic mimics may treat certain diseases, including cardiovascular, cancer, inflammatory, fibrotic and metabolic disorders. This data will be presented in a poster at the upcoming Keystone Symposia's MicroRNAs and Non-Coding RNAs and Cancer meeting February 11-16, 2011.

“We are very pleased to have obtained positive results from our collaboration with miRagen, a scientific leader in the development of microRNA therapeutics,” said Dmitry Samarsky, PhD, vice president of Technology Development at RXi. “Demonstrating that RXi's sd-rxRNA technology can be applied successfully to convert conventional microRNA mimics into highly functional self-delivering molecules was one important goal of the collaboration and creates the potential to effectively leverage the company's platform for new and exciting uses in the development of novel therapeutics.”

“microRNA therapeutics that mimic native sequences require special approaches for delivery,” said William S. Marshall, PhD, president and CEO of miRagen Therapeutics. “We are excited that RXi's self-delivering technology demonstrates this compatibility with microRNA sequences from our portfolio.”

RXi's sd-rxRNA compounds are designed to have drug-like properties, such as high potency, target specificity, serum stability, reduced immune response activation, and efficient cellular uptake. They are hybrid oligonucleotide molecules combining the beneficial properties of both conventional RNAi and anti-sense technologies. sd-rxRNAs have a single-stranded phosphorothioate region, a short duplex region, and contain a variety of nuclease-stabilizing and lipophilic chemical modifications.

RXi Pharmaceuticals is a recognized leader in RNAi-based therapeutics with a comprehensive platform that includes both RNA interference (RNAi) compounds and delivery technologies. The company is leveraging this broad and integrated platform to build a pipeline of RNAi therapeutic candidates for the treatment of a number of disease areas, including its core focus of developing treatments for dermal anti-scarring and retinal disorders as well as a continued interest in oncology and indications accessible by spinal cord delivery.