Mirus Bio Corporation has entered into a two year, multimillion dollar agreement with Pfizer Inc. to investigate and optimize gene silencing methods in animal models. The studies will utilize Mirus Bio's nucleic acid delivery platforms to target and suppress the expression of genes of interest to Pfizer.
"The lack of effective delivery methods has been the Achilles' heel impeding progress in the emerging field of RNA interference," commented Russell Smestad, Mirus Bio's president. "We are excited that this agreement will enable us to accelerate the development of our platform technologies. This agreement further enhances our position as one of the industry leaders in providing enabling nucleic acid delivery solutions."
Mirus Bio has two distinct delivery platforms. The first is "hydrodynamic intravascular injection", a method to deliver nucleic acids through the bloodstream to surrounding cells and tissues. Normally, standard injection of DNA, RNA or viral vectors into a vein or artery would result in the nucleic acids being retained within the blood vessel until degraded and filtered out of the body. However, by temporarily restricting the blood flow and rapidly injecting the nucleic acids within a large volume of a saline solution, the blood vessel wall becomes more permeable and allows the vectors to migrate into the surrounding tissue cells. This enables regional delivery throughout an entire limb or other targeted tissue rather than being localized to a single point of injection as happens with a needle and syringe. Hydrodynamic protocols have enabled high levels of gene silencing in multiple tissues.
The second delivery platform involves formulating small interfering RNA (siRNA) into nanoparticles. Unlike the hydrodynamic platform, these nanoparticles are delivered systemically via standard intravenous injection. The novel chemistry of these nanoparticles targets delivery of the siRNA to specific tissues and cells, achieves very high levels of cellular uptake, and results in highly effective silencing of targeted genes. Initial manuscripts outlining the details of this technology will be published in coming months.
RNA interference (RNAi) is a natural cellular process wherein short nucleic acids known as small interfering RNA (siRNA) regulate gene expression and protein production. In normal cells, DNA is copied to messenger RNA (mRNA) which directs the synthesis of protein. The RNAi gene silencing process involves the introduction of double-stranded RNA molecules into a cell, after which a multi step cellular process creates single-stranded siRNA molecules that interfere with the translation of mRNA into the protein it encodes. Blocking production of disease causing proteins in this manner represents a fundamentally new approach for innovative medicines. The significance of this biological pathway was highlighted in October when the two researchers credited with discovering this powerful biological phenomenon were jointly awarded "The Nobel Prize in Physiology or Medicine for 2006".
Mirus Bio Corporation is a leader in the emerging fields of gene therapy and RNA interference, based upon its expertise in nucleic acid chemistry and delivery. The company currently markets state-of-the-art DNA and siRNA transfection and labelling products to researchers worldwide.