FDA today approved a supplemental biologics application for PEG-Intron (peginterferon alfa-2b), an injectable product approved to treat patients with chronic hepatitis C infections, to be used in combination with REBETOL capsules (ribavirin).

PEG-Intron is a longer acting form of interferon than Intron A, (a previously approved form of interferon), and requires only one injection per week for one year compared to three per week for Intron A.

In January 2001, FDA approved PEG-Intron alone to treat chronic hepatitis C in patients with liver disease who had not been treated before with interferon alpha and who are at least 18 years old. Previously, FDA had approved various interferons including Intron A (interferon alfa-2b) to treat chronic hepatitis C as well as the combination of Intron A and Rebetol. This approval was based on studies indicating a better patient response to the combination than with Intron A alone. All three products -- PEG-Intron, Intron A and Rebetol -- are manufactured by the Schering Corporation, Kenilworth, N.J.

PEG-Intron with Rebetol was somewhat more effective than Intron A with Rebetol. Twenty-four weeks after treatment ended, 52% of patients who received the PEG-Intron combination had undetectable HCV virus levels in the blood compared to 46% for the Intron A combination. In patients with genotype 1 virus (a particularly difficult to treat variant of the HCV virus), the difference in sustained responses was 41% compared to 33%.

PEG-Intron with Rebetol caused the same types of adverse events as Intron A/Rebetol, but some occurred more often. Adverse events reported in the clinical trials included flu-like symptoms, psychiatric disorders (including depression), and decreases in red blood cells, (which deliver oxygen to the body), white blood cells (which help fight infection), and platelets (which help stop bleeding).

Patients taking either combination treatment must be carefully monitored by their physicians and get regular blood tests to check for side-effects and to see if the treatment is working.

A Medication Guide for patients will accompany each prescription of PEG-Intron to explain the adverse events associated with its use as well as how to most effectively use the product.

Hepatitis C infection is responsible for 8,000 to 10,000 deaths per year in the United States, according to the Centers for Disease Control and Prevention (CDC). The virus is spread mainly through contact with the blood of an infected person. About 85% of people infected with the hepatitis C virus (HCV) become chronically infected, meaning the virus stays in the blood and liver, multiplies, and may slowly attack the organ over a period of decades.

The majority of people infected with HCV do not develop severe liver disease and some may not need treatment. Most studies report that cirrhosis (advanced liver scarring) develops in 10 percent to 20 percent of people with chronic HCV infection over a period of 20 to 30 years. Liver cancer develops in 1 percent to 5 percent.

The combination of PEG-Intron and Rebetol is a new treatment option for patients with chronic hepatitis C. Although treatments come with the risk of serious side-effects, many individuals with chronic HCV infection can benefit from those treatments.