28 Jul 2011
By Ng Wan Ching
Feature Most people have the mistaken idea that the viral infection cannot be treated, but great advances have been made in its treatment methods in recent years. Ng Wan Ching reports
About 10 years ago, Mr Looi Fok Chow, 73, thought he was at death’s door.
He had frequent diarrhoea, very little energy and was found to be in the first stage of liver cirrhosis, or hardening of the liver.
This was caused by hepatitis C, a viral infection that he found out he had in 1993.
“Back then, a doctor treated my symptoms but said there was no cure for hepatitis C,” he said.
Some time around 2001, a friend recommended that Mr Looi see Associate Professor Lim Seng Gee at National University Hospital (NUH).
He did not want to change to another doctor, but his wife insisted.
The retiree, who was formerly working in the personnel department of an oil company, is glad that he listened to his wife, as he is now cured of hepatitis C.
After standard treatment with a cocktail of two drugs, his liver cirrhosis has improved to the point that it is now considered mild liver fibrosis or scarring.
Mr Looi’s story is a happy one and the best part is that it is not unusual.
Hepatitis C is a viral infection affecting about 0.2 per cent of the population here or about 10,000 people. It is transmitted through direct contact with infected blood or sexual contact.
It causes liver inflammation which can lead to liver fibrosis, then cirrhosis, liver cancer or liver failure, and death.
Symptoms include fatigue, weight loss, joint pain, nausea and fever. But many patients have no symptoms and the only way to find out if they have hepatitis C is to get a blood test.
Most people have the mistaken idea that hepatitis C is incurable, but doctors say almost 70per cent of patients with the infection can now be cured using two drugs: interferon and ribavirin.
Interferon is a chemical which the body produces when one has an illness such as influenza. It works to stop or “interfere” with the growth of viruses.
Commercially available interferon is human interferon manufactured using recombinant deoxyribonucleic acid (DNA) technology, which combines genetic material from multiple sources.
Ribavirin is an anti-viral medication.
Prof Lim, a senior consultant at the department of gastroenterology and hepatology in NUH, said: “Even if you have liver cirrhosis, you can be cured of hepatitis C. And once the hepatitis C virus is removed, the liver condition can improve.”
CURE RATES GOING UP
Cure rates for hepatitis C have been going up over the years as doctors know more about how to use drugs such as interferon and ribavirin effectively. The emergence of new drugs such as pegylated interferon has also helped.
Pegylation is a process applied to interferon to make it better utilised or absorbed by the body.
Without the chemistry of pegylation, interferon has to be injected up to three times a week for about a year. With pegylation, an interferon jab is required once a week for about a year.
When standard interferon was first used to treat hepatitis C in the 1990s, it achieved a cure rate of just 10 per cent with treatment for six months.
In the mid-1990s, standard interferon treatment for 12 months led to a cure rate of 16 per cent.
The addition of ribavirin to interferon in the late 1990s led to a significantly improved cure rate of about 40 per cent.
Pegylated interferon and ribavirin in 2001 led to cure rates of 50 to 55 per cent.
These cure rates, reported in Western countries, are even better in Asia, which are about 70 per cent for the most difficult strain of the hepatitis C virus, called genotype 1, said Prof Lim.
At Singapore General Hospital (SGH), the cure rate for the most difficult strain of hepatitis C has risen from a low of about 20 per cent a decade ago to around 70 per cent now, said Associate Professor Tan Chee Kiat, a senior consultant at its department of gastroenterology and hepatology.
ASIANS FARE BETTER
The reason cure rates for Asians are higher is that more Asians have the IL28B gene. Studies have shown that those with this gene are most likely to spontaneously clear the hepatitis C virus themselves or have the best response to interferon-based therapy.
Liver cirrhosis affects how well patients do.
Prof Tan said if a patient has significant liver cirrhosis inflicted by a long period of hepatitis C infection, then he will still require regular long-term follow-up even if he is cured of the infection.
At NUH, the cure rate for those with liver cirrhosis is 56 per cent, compared with 83 per cent for those without cirrhosis.
NEW DRUG
There is more good news: At least one drug, which can boost cure rates for hepatitis C, has recently been approved in the United States.
The US Food and Drug Administration gave the go-ahead in May for boceprevir, sold under the brand Victrelis, to treat cases of chronic hepatitisC caused by a strain of the virus called genotype 1.
The protease inhibitor, which prevents the virus from replicating, has to be used in combination with pegylated interferon and ribavirin.
In a clinical study on 1,000 patients, about 67per cent of those treated with Victrelis, pegylated interferon and ribavirin were cured, compared to 40 per cent among those who used just pegylated interferon and ribavirin.
These figures are expected to be higher in Asia, going by past trends.
Prof Lim said that in Asia, the new drug will likely be more useful to those who failed to get cures from the standard treatment.
“If they fail to achieve a cure after the first round of treatment using standard therapy, they can try again using standard therapy with Victrelis as an add-on,” he said.
The most common side effects when taken with pegylated interferon and ribavirin are tiredness, nausea, headache and taste bud changes.
The side effects of standard treatment include weight loss, some hair loss, skin rashes and, in some cases, depression.
The new drug has been submitted to the Health Sciences Authority here for approval, said a spokesman for its manufacturer, Merck, Sharp, Dohme (MSD). It costs US$1,100 (S$1,300) for a week’s supply in the United States. It is not known how much it will cost here as it has yet to be approved. An MSD spokesman said the length of treatment depends on the patient’s response to the drug and can range from 28 to 48 weeks.
Interferon injections cost $450 a week, for 48 weeks, which works out to $21,600. The ribavirin is given free with interferon.
Mr Looi said he hopes more people will get themselves tested and get treatment, as there is hope for them.
Preparing to go to Beijing to live with his son for a month, he said: “I thought my life was over 10 years ago. Look at me now. I go travelling whenever I want. I have energy and a zest for life.”
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