The scientific community, and Wall Street, will be buzzing this week about microRNA. That’s because a Carlsbad, CA-based company called Regulus Therapeutics and its collaborators have suggested for the first time that a drug that blocks microRNA can prevent and treat heart failure in animals.
Regulus, a joint venture of Cambridge, MA-based Alnylam Pharmaceuticals (NASDAQ: [[ticker:ALNY]]) and Carlsbad, CA-based Isis Pharmaceuticals (NASDAQ: [[ticker:ISIS]]) is breaking the news today online in Nature. The researchers found in a series of experiments that a tiny strand of RNA called mir21 is overactive in heart failure, and contributes to a stress reaction that causes enlargement of the muscle and inefficient blood pumping. When the scientists designed an antisense drug to specifically block mir21, it prevented those changes in the heart muscle of mice, and was able to reverse that condition in mice who already had the disease, researchers said.
MicroRNAs weren’t discovered until 1993 in worms, and not until 2001 in humans. They are thought to have big potential as drugs, because they can affect not just one gene or protein in isolation, but full networks of genes-a strategy which might be useful in treating complex diseases like diabetes or congestive heart failure, where multiple genes can get messed up. Heart failure, which can occur after stress from a heart attack, certain infections, or high blood pressure, affects about five million patients in the U.S.
“This is big news for the field,” says Kleanthis Xanthopoulos, CEO of Regulus. “This is the first time we believe anyone has demonstrated a therapeutic affect of a drug to inhibit microRNA.”
Until this finding, researchers have been only been able to show microRNAs can have an impact on “surrogate” measurements that suggest early promise against a disease but don’t say for sure whether the drug is really altering the disease. Examples are when a treatment lowers cholesterol, it might reduce the risk of heart attack, or when a drug shrinks tumors, it might help cancer patients live longer, Xanthopoulos says.
