Schering-Plough Corporation announced that the US Food and Drug Administration (FDA) has approved new labelling for Pegintron (peginterferon alfa-2b) and Rebetol (ribavirin, USP) combination therapy for treating chronic hepatitis C in patients three years of age and older with compensated liver disease. With approval of this expanded indication, Pegintron and Rebetol is the first and only pegylated interferon combination therapy approved in the United States that is not restricted to treatment-naive patients. Patients less likely to benefit from retreatment after failing a course of therapy include those with previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, or HCV genotype 1 infection. It is estimated that more than 100,000 patients in the United States failed prior treatment of their hepatitis C virus (HCV) infection, representing a large and growing patient population.

"With the FDA approval of Pegintron and Rebetol combination therapy for this new indication, US physicians now have a treatment option that offers a second chance for success to certain patients who failed prior therapy," said Robert J Spiegel, chief medical officer and senior vice president, Schering-Plough Research Institute. "This approval further underscores Schering-Plough's leadership and long-term commitment to developing new treatment options and innovative therapies to meet the needs of patients with hepatitis C."

Data from the clinical study supporting the approval helped to define those patient groups most likely to respond to retreatment as well as those unlikely to respond. Overall, previous relapsers, patients with HCV genotype 2 or 3, or those initially treated with nonpegylated interferon therapy achieved higher rates of sustained virologic response (SVR) than patients with previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, or HCV genotype 1 infection.

"Based on a patient's treatment history, physicians can identify which patients may be right for retreatment with Pegintron combination therapy and may have the best chance to achieve a sustained response," said Eugene R Schiff, director, Center for Liver Diseases, University of Miami Miller School of Medicine, and a lead investigator for the clinical study on which the approval was based. "Conversely, patients with certain treatment characteristics who are unlikely to respond to this regimen can be advised accordingly."

In the clinical study supporting the approval, achievement of undetectable virus (HCV-RNA) at treatment week 12 was a strong predictor of SVR. Patients who still had detectable virus at week 12 of therapy were highly unlikely to achieve SVR.

"Patients with undetectable virus at week 12 have a better chance for success and can be motivated to continue treatment," Schiff added, "and those patients who fail to achieve an early response can have their therapy stopped with confidence, thus avoiding unnecessary treatment and potential adverse events."

The recommended treatment duration with Pegintron combination therapy for patients who failed prior treatment is 48 weeks, regardless of HCV genotype. Retreated patients who have detectable HCV-RNA at week 12 or 24 are highly unlikely to achieve SVR and discontinuation of therapy should be considered.

Patients receiving Pegintron and Rebetol as retreatment after failing a previous interferon combination regimen reported adverse reactions similar to those previously associated with this regimen during clinical trials of treatment-naive patients.

In the United States, Pegintron is indicated for use in combination with ribavirin in patients three years of age or older, and as monotherapy in patients 18 years of age and older, for the treatment of chronic hepatitis C in patients with compensated liver disease.