Simple FactSheet: pegylated interferon (Pegasys, PEG-Intron)

Peginterferon (Pegasys, PEGIntron)
a Simple FactSheet from the AIDS Treatment Data Network

||||| Peginterferon (Pegylated interferon) is a drug used in combination with ribavirin to treat infection by the hepatitis C virus:

Pegylated interferon is a man-made form of interferon, a chemical naturally produced in the body to fight viruses. Interferon helps to stop the hepatitis C virus (HCV) from making new copies of itself. It also helps the immune system to kill HCV. Pegylated interferon is made with special add-on parts that help the drug stay in the body longer. It is injected once a week, while interferon that is not pegylated needs to be injected at least three times a week.
There are two brands of pegylated interferon: Pegasys and PEG-Intron. There are slight differences between the drugs, but both brands seem to work equally well and do not have major differences in side effects. Both are used in combination with ribavirin to treat Hepatitis C virus (HCV) infection. If left untreated, HCV infection can lead to serious liver disease such as cirrhosis, liver cancer or death.

||||| Will this drug work for me?

The main goal of treating hepatitis C is to rid the body of HCV. A viral load test is used to measure the amount of HCV in your blood. If there is no detectable amount of HCV in your blood six months after you have finished a full course of treatment, you have a sustained virological response (SVR). This means that the treatment has worked.
Your body's response to treatment depends on several things, especially what genotype (or strain) of HCV you have. If you have genotype 2 or 3, treatment is more likely to result in an SVR. If you have genotype 1a or 1b (which is the most common HCV genotype in the United States), you're less likely to have a SVR. The odds are less in your favor if you are HIV positive, have an HCV viral load over 2 million, or if you have liver cirrhosis. Having a fatty liver (steatosis) or insulin resistance also appears to reduce your chances of having an SVR, but people with tghese conditions have responded in some cases so discuss ways to potentially treat them before starting HCV treatment.
In addition, clinical trials have shown that HCV treatment is not as effective for African Americans. More research is needed to find out why, but it has been suggested that African Americans have different variants of the receptors involved with HCV infection as well as lower neutrophil counts to begin with. That does not mean that all African Americans do not respond to treatment. It also appears that with some of the experimental treatments being studied, African Americans might possibly not be at a disadvantage. These experimental drugs being tested might make treating chronic HCV take less time or be more effective for everyone.
Research has shown that it is much more effective to treat HCV using a combination of pegylated interferon and ribavirin than treating without ribavirin. For people infected with HCV only, SVR is achieved in about 45-50% with genotype 1, and over 80% with genotype 2 or 3 when treated with the combination. When treating with pegylated interferon alone without ribavirin, SVR is about 15% in genotype 1 and about 35% in genotype 2 or 3. In people co-infected with HIV and HCV, combination treatment results in SVR rates range from 14% to 29% for genotype 1, and 44% to 73% for genotype 2 or 3. Treating with only pegylated interferon without ribavirin is not recommended for those co-infected with HIV and HCV.

||||| Dosage:

Current treatment guidelines from the American Association for the Study of Liver Diseases recommend that people co-infected with HIV and HCV receive combination treatment for 48 weeks for all genotypes. Some doctors are treating co-infected people with genotype 1 for 72 weeks. People with HCV alone and genotype 2 or 3 typically only need 24 weeks of treatment. Many doctors will stop treatment if your HCV viral load does not drop significantly after the first 12 weeks of treatment. Having an Early Virologic Response (EVR) 4 weeks after starting treatment increaes the chances your full treatment will work, but people who have greater than a 2 log reduction in HCV viral load or who become undetectable at 12 weeks still have a good chance of having an SVR even if they did not have an EVR. An EVR is something you would like to see occur, but it just doesn't in everyone who ultimately achieves an SVR.
Pegylated interferon is administered by injection under the skin (subcutaneous).
Pegasys comes in pre-filled syringes that need to be refrigerated. The usual dose of Pegasys is 180 µg, taken once a week. The dose may be lowered if you're experiencing serious side effects, although lower doses may be less effective. Pegasys has not been approved for use in children.
PEG-Intron comes in a pre-filled pen that contains powder and sterile water; pushing down on the pen mixes them together. The pens need to be refrigerated. The dose of PEG-Intron depends on weight-1.5 µg per kilogram (range: 50 - 150 µg total), taken once a week. The dose may be lowered if you're experiencing serious side effects, although lower doses may be less effective. PEG-Intron has recently been approved for treating children with chronic Hepatitis C in the United States.

||||| Side effects:

Side effects cause many people to stop HCV treatment. Side effects may be more severe for people co-infected with HIV and HCV. Before starting treatment, talk to people who have been through it, educate yourself, and make sure you ask family and friends for support.
Flu-like symptoms such as fever, chills, headache, muscle ache, and fatigue are common side effects of treatment. Other symptoms are fatigue or extreme tiredness. Nausea and loss of appetite are also common. The flu-like symptoms are usually the worst right after taking the weekly injection; some people schedule their injection for a time each week when they know they'll be able to rest and take it easy afterwards. Some of these symptoms can be reduced by taking pain relief drugs an hour or two before each injection. Drinking lots of water is necessary.
Depression and related symptoms, such as anxiety, irritability, insomnia, and mental confusion, are common during treatment. This is especially true in people with a history of depression. People may also experience mental confusion, and difficulty with concentration and memory. While less common, other psychiatric side effects include aggressive behavior, psychosis, hallucinations, and mania; a few cases of suicide have been reported. People considering HCV treatment should receive a psychiatric evaluation before starting, and be closely monitored during treatment. Some doctors prescribe an antidepressant before starting treatment to prevent depression. If depression occurs during treatment, options include antidepressants, reducing the dose of pegylated interferon, or discontinuing treatment.
Pegylated interferon can also reduce levels of white blood cells. Some people taking pegylated interferon develop neutropenia (reduced levels of neutrophils, a type of white blood cell). Neutropenia can put people at risk for developing other infections. If neutropenia occurs during treatment, options include shots of Neupogen (filgrastim), a growth factor to boost neutrophil levels, reducing the dose of pegylated interferon, or discontinuing treatment.
People with HIV generally see their overall CD4 T cell count decrease temporarily during interferon treatment, although the CD4 T cell count usually returns to baseline after treatment. There is typically not a reduction in the percentage of CD4 cells, however. The lower the CD4 cell count, the less likely treatment will work as well as for people with people with higher CD4 cells, but it does still work. More side effects and the potential of developing HIV-related opportunistic infections increases if the CD4 count is very low, however, and adding preventative medications onto the HCV regimen can be complicated and increase the potential of side effects from those medications.
Pegylated interferon can also cause thrombocytopenia (reduced levels of platelets, a type of cell that helps blood to clot). If thrombocytopenia occurs during treatment, options include reducing the dose of pegylated interferon or, in severe cases, stopping treatment.
Colitis (inflammation of the colon) and pancreatitis (inflammation of the pancreas) may occur in some people. If these serious conditions appear, treatment should be stopped. Heart and thyroid problems, some lung disorders, and autoimmune diseases have also been reported. Pegylated interferon can worsen these conditions in people who already have them before treatment.
Other side effects can include vision problems, itching, hair loss, and injection site reactions (soreness or swelling at the site of injection). It is also important to be aware of the potential side effects of ribavirin.

||||| Warnings:

Research has shown that pegylated interferon should not be used by people with the following conditions: 1) decompensated cirrhosis; 2) autoimmune hepatitis; 3) major, uncontrolled depression; 4) kidney, lung or heart transplants; or 5) known hypersensitivity (allergic reaction) to pegylated interferon components. Pegylated interferon should be used with caution, preferably by a specialist, in people with heart and thyroid problems, pulmonary disorders, and autoimmune diseases.
Since pegylated interferon requires injection, some former drug injectors and people in recovery may feel uncomfortable or triggered by using needles, especially since some of the side effects can feel like heroin withdrawal symptoms. Get support and consider asking if a doctor, a nurse, or your care-giver can give you the injections. Having a history of alcohol, substance abuse, injection drug use does not mean you will not respond to treatment. Curent use makes treatment very difficult, but requires a multi-disciplinary team of clinicians and counselors. Being successfully treated for chronic hepatitis C does not mean that you are protected against getting infected again.
Pegylated interferon can increase blood levels of theophylline, an asthma medication. If you are taking theophylline and pegylated interferon, your doctor should monitor blood levels of theophylline and may adjust the dose.

Pegylated interferon and ribavirin are available through patient assistance programs, some ADAPs, and are covered by some insurance plans. Before you start treatment you should know who will pay for what. For clinical trials of other treatments or experimental drugs to treat chronic Hepatitis C or Hepatitis B, contact the Network.

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AIDS Treatment Data Network • The Access Project
Last modified: 12/29/2008
Contact The Network

\|\|\|\|\| Peginterferon (Pegylated interferon) is a drug used in combination with ribavirin to treat infection by the hepatitis C virus:
Pegylated interferon is a man-made form of interferon, a chemical naturally produced in the body to fight viruses. Interferon helps to stop the hepatitis C virus (HCV) from making new copies of itself. It also helps the immune system to kill HCV. Pegylated interferon is made with special add-on parts that help the drug stay in the body longer. It is injected once a week, while interferon that is not pegylated needs to be injected at least three times a week. There are two brands of pegylated interferon: Pegasys and PEG-Intron. There are slight differences between the drugs, but both brands seem to work equally well and do not have major differences in side effects. Both are used in combination with ribavirin to treat Hepatitis C virus (HCV) infection. If left untreated, HCV infection can lead to serious liver disease such as cirrhosis, liver cancer or death.
\|\|\|\|\| Will this drug work for me?
The main goal of treating hepatitis C is to rid the body of HCV. A viral load test is used to measure the amount of HCV in your blood. If there is no detectable amount of HCV in your blood six months after you have finished a full course of treatment, you have a sustained virological response (SVR). This means that the treatment has worked. Your body's response to treatment depends on several things, especially what genotype (or strain) of HCV you have. If you have genotype 2 or 3, treatment is more likely to result in an SVR. If you have genotype 1a or 1b (which is the most common HCV genotype in the United States), you're less likely to have a SVR. The odds are less in your favor if you are HIV positive, have an HCV viral load over 2 million, or if you have liver cirrhosis. Having a fatty liver (steatosis) or insulin resistance also appears to reduce your chances of having an SVR, but people with tghese conditions have responded in some cases so discuss ways to potentially treat them before starting HCV treatment. In addition, clinical trials have shown that HCV treatment is not as effective for African Americans. More research is needed to find out why, but it has been suggested that African Americans have different variants of the receptors involved with HCV infection as well as lower neutrophil counts to begin with. That does not mean that all African Americans do not respond to treatment. It also appears that with some of the experimental treatments being studied, African Americans might possibly not be at a disadvantage. These experimental drugs being tested might make treating chronic HCV take less time or be more effective for everyone. Research has shown that it is much more effective to treat HCV using a combination of pegylated interferon and ribavirin than treating without ribavirin. For people infected with HCV only, SVR is achieved in about 45-50% with genotype 1, and over 80% with genotype 2 or 3 when treated with the combination. When treating with pegylated interferon alone without ribavirin, SVR is about 15% in genotype 1 and about 35% in genotype 2 or 3. In people co-infected with HIV and HCV, combination treatment results in SVR rates range from 14% to 29% for genotype 1, and 44% to 73% for genotype 2 or 3. Treating with only pegylated interferon without ribavirin is not recommended for those co-infected with HIV and HCV.
\|\|\|\|\| Dosage:
Current treatment guidelines from the American Association for the Study of Liver Diseases recommend that people co-infected with HIV and HCV receive combination treatment for 48 weeks for all genotypes. Some doctors are treating co-infected people with genotype 1 for 72 weeks. People with HCV alone and genotype 2 or 3 typically only need 24 weeks of treatment. Many doctors will stop treatment if your HCV viral load does not drop significantly after the first 12 weeks of treatment. Having an Early Virologic Response (EVR) 4 weeks after starting treatment increaes the chances your full treatment will work, but people who have greater than a 2 log reduction in HCV viral load or who become undetectable at 12 weeks still have a good chance of having an SVR even if they did not have an EVR. An EVR is something you would like to see occur, but it just doesn't in everyone who ultimately achieves an SVR. Pegylated interferon is administered by injection under the skin (subcutaneous). Pegasys comes in pre-filled syringes that need to be refrigerated. The usual dose of Pegasys is 180 µg, taken once a week. The dose may be lowered if you're experiencing serious side effects, although lower doses may be less effective. Pegasys has not been approved for use in children. PEG-Intron comes in a pre-filled pen that contains powder and sterile water; pushing down on the pen mixes them together. The pens need to be refrigerated. The dose of PEG-Intron depends on weight-1.5 µg per kilogram (range: 50 - 150 µg total), taken once a week. The dose may be lowered if you're experiencing serious side effects, although lower doses may be less effective. PEG-Intron has recently been approved for treating children with chronic Hepatitis C in the United States.
\|\|\|\|\| Side effects:
Side effects cause many people to stop HCV treatment. Side effects may be more severe for people co-infected with HIV and HCV. Before starting treatment, talk to people who have been through it, educate yourself, and make sure you ask family and friends for support. Flu-like symptoms such as fever, chills, headache, muscle ache, and fatigue are common side effects of treatment. Other symptoms are fatigue or extreme tiredness. Nausea and loss of appetite are also common. The flu-like symptoms are usually the worst right after taking the weekly injection; some people schedule their injection for a time each week when they know they'll be able to rest and take it easy afterwards. Some of these symptoms can be reduced by taking pain relief drugs an hour or two before each injection. Drinking lots of water is necessary. Depression and related symptoms, such as anxiety, irritability, insomnia, and mental confusion, are common during treatment. This is especially true in people with a history of depression. People may also experience mental confusion, and difficulty with concentration and memory. While less common, other psychiatric side effects include aggressive behavior, psychosis, hallucinations, and mania; a few cases of suicide have been reported. People considering HCV treatment should receive a psychiatric evaluation before starting, and be closely monitored during treatment. Some doctors prescribe an antidepressant before starting treatment to prevent depression. If depression occurs during treatment, options include antidepressants, reducing the dose of pegylated interferon, or discontinuing treatment. Pegylated interferon can also reduce levels of white blood cells. Some people taking pegylated interferon develop neutropenia (reduced levels of neutrophils, a type of white blood cell). Neutropenia can put people at risk for developing other infections. If neutropenia occurs during treatment, options include shots of Neupogen (filgrastim), a growth factor to boost neutrophil levels, reducing the dose of pegylated interferon, or discontinuing treatment. People with HIV generally see their overall CD4 T cell count decrease temporarily during interferon treatment, although the CD4 T cell count usually returns to baseline after treatment. There is typically not a reduction in the percentage of CD4 cells, however. The lower the CD4 cell count, the less likely treatment will work as well as for people with people with higher CD4 cells, but it does still work. More side effects and the potential of developing HIV-related opportunistic infections increases if the CD4 count is very low, however, and adding preventative medications onto the HCV regimen can be complicated and increase the potential of side effects from those medications. Pegylated interferon can also cause thrombocytopenia (reduced levels of platelets, a type of cell that helps blood to clot). If thrombocytopenia occurs during treatment, options include reducing the dose of pegylated interferon or, in severe cases, stopping treatment. Colitis (inflammation of the colon) and pancreatitis (inflammation of the pancreas) may occur in some people. If these serious conditions appear, treatment should be stopped. Heart and thyroid problems, some lung disorders, and autoimmune diseases have also been reported. Pegylated interferon can worsen these conditions in people who already have them before treatment. Other side effects can include vision problems, itching, hair loss, and injection site reactions (soreness or swelling at the site of injection). It is also important to be aware of the potential side effects of ribavirin.
\|\|\|\|\| Warnings:
Research has shown that pegylated interferon should not be used by people with the following conditions: 1) decompensated cirrhosis; 2) autoimmune hepatitis; 3) major, uncontrolled depression; 4) kidney, lung or heart transplants; or 5) known hypersensitivity (allergic reaction) to pegylated interferon components. Pegylated interferon should be used with caution, preferably by a specialist, in people with heart and thyroid problems, pulmonary disorders, and autoimmune diseases. Since pegylated interferon requires injection, some former drug injectors and people in recovery may feel uncomfortable or triggered by using needles, especially since some of the side effects can feel like heroin withdrawal symptoms. Get support and consider asking if a doctor, a nurse, or your care-giver can give you the injections. Having a history of alcohol, substance abuse, injection drug use does not mean you will not respond to treatment. Curent use makes treatment very difficult, but requires a multi-disciplinary team of clinicians and counselors. Being successfully treated for chronic hepatitis C does not mean that you are protected against getting infected again. Pegylated interferon can increase blood levels of theophylline, an asthma medication. If you are taking theophylline and pegylated interferon, your doctor should monitor blood levels of theophylline and may adjust the dose. Pegylated interferon and ribavirin are available through patient assistance programs, some ADAPs, and are covered by some insurance plans. Before you start treatment you should know who will pay for what. For clinical trials of other treatments or experimental drugs to treat chronic Hepatitis C or Hepatitis B, contact the Network.