Regulus Theraputics is developing a groundbreaking treatment for hepatitis C

Regulus Theraputics is developing a groundbreaking treatment for hepatitis C

By Eilene Zimmerman

Posted on Fri, Mar 19th, 2010

Last updated Thu, Mar 18th, 2010


There are a plethora of small biotech companies in San Diego working on treatments for diseases. One of those is Carlsbad-based Regulus Therapeutics, which has focused its research on something known as microRNA—one of the most profound scientific discoveries in the last decade. MicroRNA’s are small RNA molecules that regulate how proteins in our genes function. A single microRNA can orchestrate the expression of broad networks of genes in cells, which can affect that cell’s activities.


When a microRNA is disregulated, cell function is disrupted—and that can cause a disease to progress. MicroRNA medicines target these dysfunctional microRNA’s, normalizing cell function and halting a disease’s progress. This is what Regulus aims to do for hepatitis C.


In February, the company inked a deal with pharmaceutical giant GlaxoSmithKline to develop and commercialize a therapy to treat the disease, which affects more than three million Americans and about 170 million people worldwide. (KPBS reported last year that more than 4,000 San Diegans are infected.) Up to 85 percent of those infected develop chronic hepatitis C. Over time, the disease causes tiny scars to form in the liver, making it hard for the organ to work well. About 25 percent of people who develop chronic hepatitis C eventually develop more serious liver problems such as cirrhosis or liver cancer.


The current treatment—a combination of anti-viral medications—can cause some serious side effects and cures only half the patients treated, so many companies are working to find a better solution. Kleanthis G. Xanthopoulos, CEO of Regulus, says the GSK deal gives the company a lot of cash to pursue the hepatitis C treatment although it has other microRNA programs—inoncology, immuno-inflammatory diseases and in metabolic diseases. This is Regulus’ second collaboration with GSK—the first began in 2008 for autoimmune diseases.


“They liked what they saw and were happy with the progress," says Xanthopoulos. "We were approached by their anti-infection group about finding new medicines for hepatitis C and that led to this second collaboration."


The deal could be worth as much as $160 million, he says, and Regulus received a significant amount up front.


“Within the first year, we expect $10 million,” says Xanthopoulos, who notes that developing drugs is an expensive proposition. That potential $160 million may sound like a lot of money, but in the language of drug development, that will make Regulus financially solid for three years. The company will be growing its current staff by 10-20 percent over the next year. Although GSK now has a “small but significant” minority equity stake in Regulus, the Carlsbad company will remain fully independent.


Ultimately, any microRNA treatments developed by Regulus and GSK would be used in conjunction with other drugs, both those existing and currently in development, and Xanthopoulos says there are about 25 other ones being pursued.


“Ours would be a weekly injection of a molecule that blocks the function of a microRNA that’s used by the hepatitis C virus to propagate itself," he says. "Our drug will take that ability away from the virus. You want to hit the virus and hit it hard as possible, that’s why you need multiple therapies.”


Viruses are known to mutate around drugs but won’t be able to do that with Regulus’ drug. “Ours is a somatic factor—it’s not part of the virus, our drug is blocking its ability to replicate,” says Xanthpoulos, who has spent the last decade working to find a new treatment for hepatitis C. “This represents a whole new class of drugs, and it’s very exciting,” he says. “We want to eradicate the disease.”