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 이성욱 ( 2010-11-02 09:33:00 , Hit : 2519
 Strides Against Hepatitis C Open Door to Blockbusters

By JONATHAN D. ROCKOFF
The pharmaceutical industry, which has been looking for new drugs to replace aging blockbusters, is on the verge of getting a big boost from research advances against hepatitis C.

Drug makers including Merck & Co., Johnson & Johnson and Bristol-Myers Squibb Co. have been racing to come up with new treatments for the disease, which kills at least 10,000 Americans each year and is a leading reason for liver transplants in the U.S., according to the National Institute of Diabetes and Digestive and Kidney Diseases.

Current therapies can take up to a year and work in fewer than half of the most typical patients. And by some estimates, only a quarter of the estimated four million infected Americans even know they have hepatitis C, so drug makers see enormous potential for new therapies. The market will more than double by 2015, to $9 billion in global sales, according to Phil Nadeau, a Cowen & Co. analyst.

Such sales would give drug makers a jolt, as the companies need to replace tens of billions of dollars in revenue they will lose as top-selling drugs are stripped of their patent protection over the next few years.

Leading the wave of potential new treatments are two antiviral agents—telaprevir from J&J in partnership with Vertex Pharmaceuticals Inc., and boceprevir from Merck. Preliminary results of pivotal late-stage trials suggest addition of these antivirals to current treatments cured hepatitis C in three-fifths or more of patients, in as little as six months.

"It's the most significant advance in this field in [years] and really addresses a substantial need," said Peter Kim, Merck's head of research and development.

Merck and Vertex are both releasing full results from their phase III studies Saturday at a scientific meeting in Boston. And the companies say they expect to ask the Food and Drug Administration by the end of this year for approval, which is widely expected during the first half of next year.

It's unusual "for drugs to really increase cure rates and treatment effect by this much. Usually, they are much more incremental," said Bob Kauffman, Vertex's chief medical officer.

Hepatitis C can become a chronic infection that damages the liver.

The virus is spread through contact with infected blood, sharing of contaminated needles and sexual intercourse. Many of the infected contracted the disease in the 1960s to 1980s, but have gone years without knowing it. Symptoms might not appear until a patient's liver is near failing or has become cancerous, doctors say.

More than 170 million people world-wide have the disease, according to the World Health Organization.

Current treatment is limited. Patients take a combination of two agents, an extended-release interferon that's injected and an antiviral pill, ribavirin. These medicines aim to boost the body's ability to fight off the virus. But they can be difficult to take, causing flu-like symptoms and depression, for the year of treatment. What's more, they work in just a minority of patients.

Advances in understanding how the virus replicates have helped pave the way for new therapies, said Jake Liang, chief of the NIDDK's liver-disease branch. Though studies indicate the latest agents improve cure rates, they don't eliminate side effects.

"We are getting better efficacy" from the latest therapies, said Dr. Liang, "but we are not really getting rid of the side effects. It's a trade-off."

Clinical-trial results released so far indicate that both telaprevir and boceprevir appear to work much better than the current treatment, though doctors might prefer telaprevir because it seems easier to use, said Jorge Herrera, a University of South Alabama hepatologist who was an investigator in boceprevir trials and has been traveling around the country lecturing doctors about using the new treatments.

Roche Holding AG and Merck dominate the hepatitis C market currently, but more than 30 therapies from over a dozen companies are under development, Cowen's Mr. Nadeau says.

Several companies are trying to make an improved version of extended-release interferon, including Bristol-Myers, which earlier this month paid $735 million for ZymoGenetics and its experimental interferon in phase II of development.

Much research is focused on trying to stop the hepatitis C virus in its tracks. Telaprevir and boceprevir are among so-called protease inhibitors that try to block the virus from replicating.

Earlier this month, Roche bought the world-wide development and commercialization rights to a protease inhibitor in phase II that the company has been developing with InterMune Inc., for $175 million in cash.

More than a half-dozen companies are developing polymerase inhibitors, which also seek to halt the virus's multiplication but by targeting a different enzyme responsible for the virus's replication. Pfizer Inc.'s polymerase inhibitor, for instance, is in phase II.

These companies hope to tap into the many hepatitis C sufferers who are on the sidelines, either because they aren't yet aware of infection or have been waiting for better treatment.

Among those holding out is James Whitney. Since being diagnosed in 1997, Mr. Whitney, 58 years old, has tried to rid his body of the virus twice, but each attempt at treatment failed. First, he took interferon for three months, when that antiviral agent was the only therapy available. Earlier this year, he tried a combination of extended-release interferon and ribavirin, but that still didn't help.

Mr. Whitney, who lives on Mississippi's Gulf Coast, is concerned about complications as serious as liver cancer if his condition isn't treated.

"I am anxiously waiting for something to come out that will actually work," said Mr. Whitney.







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