Contact: Alexander Shtifman
Phone: 617-713-8989
alex...@childrens.harvard.edu

Researchers at the Immune Disease Institute-formerly the Immune Disease Institute-have overcome a major hurdle in the delivery of therapeutics to the brain: getting past the blood-brain-barrier (BBB) which excludes most large and small molecule drugs. Their breakthrough research is published in the June 17, 2007 issue of Nature magazine, with Manjunath Swamy, M.D., as principal investigator and Priti Kumar, Ph.D., as first author on the paper, with collaboration from scientists at the University of Iowa and Hanyang University in South Korea.

The BBB-comprised of the endothelial walls of 100 billion capillaries in the brain-is a superfine filter that prevents transport of harmful pathogens and beneficial drugs alike. To overcome the BBB in situations of disease, IDI researchers in the Swamy lab employed a modified Rabies virus glycoprotein peptide named CORVUS that slipped past the BBB and, in mice, delivered small interfering RNAs as a therapy to neuronal cells in the brain. The siRNAs effected specific gene silencing in the brain, without side effects.

A visionary discovery, this new technology from the Swamy lab provides a non-invasive, intravenous means of delivering, throughout the brain, the powerful therapy known as RNA interference (which suppresses disease-causing genes) as well as, potentially, DNA for gene therapy. The CORVUS technology also promises to be a brain delivery system for a wide slate of conventional drugs in the form of antibodies, proteins, and other compounds.

Many late-stage clinical trials have failed when candidate drugs are frustrated at the BBB; this new ability to send therapies selectively to the brain may revolutionize the treatment of diseases including Alzheimer's, Parkinson's, multiple sclerosis, psychiatric illnesses such as schizophrenia, fatal infections including encephalitis and meningitis, and central nervous system traumas, among other illnesses.

Previously, Swamy, Priti Kumar, and colleagues had used RNAi to defeat brain infection caused by Japanese encephalitis and West Nile virus. With the breakthrough CORVUS technology, they will be able to prevent such deadly infections in mice by administering the same siRNAs intravenously.

In addition, there is a great need for new therapeutics for Alzheimer's and other "neuronal" diseases associated with aging, as the U.S. population becomes older. Effective delivery of therapies to the brain is a vital component for making progress against these diseases.