The compound, from Danish biotech firm Santaris Pharma,  works by blocking or “silencing” microRNAs — tiny strands of  RNA, or ribonucleic acid, that help turn genes into proteins. The ground-breaking study is the first demonstration of  microRNA silencing in primates and an early endorsement of the  technique. Phase I safety trials are now planned in humans. Unlike other drugs in the hotly pursued RNA interference  field, the new designer molecule, known as Locked Nucleic Acid  (LNA), can be given as a simple injection rather than having to  be delivered direct to affected tissue. “We think LNA is a one-stop shop for silencing,” Santaris  Chief Executive Keith McCullagh told reporters. Scientists from Santaris and the University of Copenhagen  lowered total cholesterol in African green monkeys by up to 30  percent, without ill effects, by targeting a microRNA linked to  genes in the liver that are involved in cholesterol metabolism. The results were published in the journal Nature, along  with other test-tube research showing that LNA effectively  blocks the production of hepatitis C virus in human liver  cells. Santaris intends to test its first LNA compounds in humans  by the middle of this year but it will take at least five years  before any medicine is ready for submission for approval. While the cholesterol effect is interesting, McCullagh said  the most promising opportunity actually lay in pursuing LNA as  a treatment for hepatitis C, a poorly treated viral disease  that can cause serious liver damage. Further ahead, LNA could also have a role to play in other  infectious diseases, as well as cancer and autoimmune  disorders, since many disease-associated genes are regulated by  microRNAs. “There are great prospects for future drug development both  for liver diseases and other disease types, and Europe has the  potential to match the USA in this area,” said Mike Gait at the  MRC Laboratory of Molecular Biology in Cambridge. Up until now, U.S. firms such as Alnylam Pharmaceuticals  Inc and Sirna Therapeutics — which was bought by Merck & Co  Inc for $1.1 billion in October 2006 — have led the field in  RNA interference. Santaris last year signed a pact that could earn it more  than $700 million with GlaxoSmithKline Plc, giving Europe’s  biggest drugmaker the right to develop certain products as  antiviral medicines. That alliance did not include the new  technology but McCullagh said Santaris could potentially extend  the Glaxo deal. For a story on Santaris Pharma’s possible IPO, please click  on
"New kind of gene ""silencing"" drug works in monkeys."