Peg-Intron (peginterferon alfa-2b)

The following drug information is obtained from various newswires, published medical journal articles, and medical conference presentations.


Approval Status:

Approved January 2001

Specific Treatments:

Chronic hepatitis C

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General Information

Peg-Intron (peginterferon alfa-2b) Powder for Injection has been approved by the FDA as a once-weekly monotherapy for the treatment of chronic hepatitis C. It is indicated for patients with compensated liver disease who were not previously treated with alpha interferon. Peg-Intron is the first pegylated interferon to be approved in the United States, and therefore offers a new treatment option for hepatitis patients.

Peg-Intron is a longer-acting formulation of Schering-Plough's Intron A, which is a recombinant version of a naturally occurring alpha interferon. In contrast to Intron A, which is administered three times weekly, Peg-Intron is administered subcutaneously once a week. This reduced frequency of administration may increase patient compliance.

Hepatitis C is a liver disease caused by the hepatitis C virus, which is spread by contact with the blood of an infected person. According to the Centers for Disease Control, approximately four million Americans are infected with the hepatitis C virus and approximately 70% of infected patients develop chronic liver disease.

Clinical Results

Peg-Intron was evaluated in a randomized, controlled trial that included 1,219 adult subjects with chronic hepatitis C who were not previously treated with alpha interferon. The trial compared Peg-Intron (0.5, 1.0 or 1.5 mcg/kg) administered subcutaneously once weekly to Schering-Plough's Intron A (recombinant interferon alfa-2b) Injection (3 MIU) administered subcutaneously three times weekly.

Treatment was administered for 48 weeks, and subjects were also followed for 24 weeks post-treatment. Subjects receiving the 1.0 mcg/kg dose of Peg-Intron achieved a 24% treatment response rate of sustained virologic response and ALT normalization, whereas a 12% treatment response rate was observed in subjects receiving Intron A.

Side Effects

Alpha interferons such as Peg-Intron may cause serious neuropsychiatric, autoimmune, ischemic and infectious disorders. As a result, patients receiving treatment should be closely monitored, and those with persistently severe or worsening signs or symptoms of these conditions should discontinue therapy.

In clinical trials, nearly all subjects experienced one or more adverse events. The most common adverse events associated with Peg-Intron were "flu-like" symptoms, which occurred in approximately 50% of subjects. Injection site irritation or inflammation was seen in 47% of subjects, and depression was reported in approximately 29% of subjects.

Mechanism of Action

Peg-Intron utilizes proprietary PEG technology developed by Enzon. By linking recombinant interferon to a 12,000 dalton polyethylene glycol (PEG) molecule, the anti-viral properties of interferon can be sustained for a longer period of time.

Interferons bind to specific cell surface membrane receptors and have been shown to exert antiviral and immunomodulatory effects. After binding to the cell membrane, the glycoproteins initiate intracellular events including the suppression of cell proliferation, the enhancement of macrophage activity, and the inhibition of viral replication in infected cells. (from Intron A Prescribing Information)

Additional Information

Please visit the company web site for additional information on Schering-Plough products.

If you would like more information on hepatitis C, please visit the Centers for Disease Control and Prevention.