Pegasys is a medicine that contains the active substance peginterferon alfa-2a. It is available as a solution for injection in a vial and as a pre-filled syringe (135 and 180 micrograms).
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Pegasys is used to treat adult patients with the following diseases:
- chronic (long-term) hepatitis B (a disease of the liver due to infection with the hepatitis B virus). It is used in patients who have compensated liver disease (when the liver is damaged but works normally), who also show signs that the virus is still multiplying, and have signs of liver damage (raised levels of alanine aminotransferase [ALT], a liver enzyme, and signs of damage when liver tissue is examined under a microscope);
- chronic hepatitis C (a disease of the liver due to infection with the hepatitis C virus). It can be used in patients with liver cirrhosis (scarring) and in patients also infected with human immunodeficiency virus (HIV). The best way to use Pegasys is with ribavirin (an antiviral medicine). This combination is suitable for treatment-naïve patients (who have not been treated before) and for patients in whom previous treatment including any type of interferon alfa, with or without ribavirin, did not work. Pegasys can be used on its own if the patient does not tolerate or must not receive ribavirin. The medicine can only be obtained with a prescription.
Treatment with Pegasys should be started by a doctor who has experience in the treatment of hepatitis B or C. Pegasys is given by injection under the skin in the abdomen (tummy) or thigh. It is usually given as 180 micrograms once a week for 48 weeks, although some hepatitis C patients may need 16, 24 or 72 weeks of treatment. The dose may need to be adjusted for patients who experience side effects. For full dosing information, see the Summary of Product Characteristics (also part of the EPAR).
The active substance in Pegasys, peginterferon alfa-2a, belongs to the group ?interferons?. Interferons are natural substances produced by the body to help it fight against attacks such as infections caused by viruses. The exact way alpha interferons work in viral diseases in not fully understood, but it is thought that they act as immunomodulators (substances that modify how the immune system, the body?s defence system, works). Alpha interferons may also block the multiplication of viruses. Peginterferon alfa-2a is very similar to interferon alfa-2a, which is already available in the European Union (EU) as Roferon. In Pegasys, the interferon alfa-2a has been ?pegylated? (coated with a chemical called polyethylene glycol). This decreases the rate at which the substance is removed from the body and allows the medicine to be given less often. The interferon alfa-2a in Pegasys is produced by a method known as ?recombinant DNA technology?: it is made by a bacterium that has received a gene (DNA), which makes it able to produce interferon alfa-2a. The replacement acts in same way as naturally produced interferon alpha.
In chronic hepatitis C, Pegasys has been studied on its own in three studies involving a total of 1,441 patients, and in combination with ribavirin in one study involving 1,149 patients. All of these studies lasted 48 weeks, and compared the effectiveness of Pegasys with that of interferon alfa-2a. Additional studies looking at the combination of Pegasys and ribavirin included one study comparing two doses and two durations of treatment (24 or 48 weeks) in 1,285 patients, one study comparing 16 and 24 weeks of treatment in 1,469 patients, one study in 514 patients with normal ALT levels, one study in 860 patients who were also infected with HIV, and a final study in 950 patients who did not respond to previous treatment with peginterferon alfa-2b and ribavirin.
In chronic hepatitis B, two studies have been carried out comparing Pegasys with lamivudine (another antiviral medicine) in 820 ?HBeAg-positive? patients (infected with the common type of the hepatitis B virus) and in 552 ?HBeAg-negative? patients (infected with a virus that has mutated [changed], leading to a form of chronic hepatitis B that is more difficult to treat).
In all cases, the main measure of effectiveness was the disappearance of the markers of hepatitis virus infection from the blood after treatment and at ?follow-up? six months later.
In chronic hepatitis C, Pegasys on its own was more effective than interferon alfa-2a. More patients responded to treatment, with 28 to 39% of patients in the Pegasys group having no markers of hepatitis virus infection in their blood at follow-up, compared with 8 to 19% in the interferon alfa-2a group. When it was used in combination with ribavirin, Pegasys was more effective than when it was used on its own (45% responders at follow-up compared with 24%), and was as effective as the combination of interferon alfa-2a and ribavirin (39% responders). The additional studies confirmed the effectiveness of Pegasys, including in patients with HIV and those who did not respond to previous treatment.
In chronic hepatitis B, Pegasys was more effective than lamivudine in both HBeAg-positive and -negative patients. The proportions of patients with no signs of viral activity in their blood at follow-up were 32% with Pegasys and 22% with lamivudine in the HBeAg-positive patients, and 43% with Pegasys and 29% with lamivudine in the HBeAg-negative patients.
The most common side effects with Pegasys (seen in more than 1 patient in 10) are anorexia (loss of appetite), headache, insomnia (difficulty sleeping), irritability, depression, dizziness, nausea (feeling sick), diarrhoea, abdominal (tummy) pain, alopecia (hair loss), pruritus (itching), myalgia (muscle pain), arthralgia (joint pain), fatigue (tiredness), pyrexia (fever), rigors (shaking chills), reactions at the site of the injection and pain. For the full list of all side effects reported with Pegasys, see the Package Leaflet.
Pegasys should not be used in people who may be hypersensitive (allergic) to alpha interferons or any of the other ingredients. Pegasys should not be used in:
- patients with auto-immune hepatitis (when the body attacks the liver);
- patients with severe liver problems;
- patients with a history of severe heart disease;
- HIV-infected patients with signs of serious liver disease. For a list of all restrictions with Pegasys, see the Package Leaflet.