KENILWORTH, N.J. -- Early virologic response (EVR) in patients with chronic hepatitis C following 12 weeks of individualized, weight-based dosing of PEG-INTRON (peginterferon alfa-2b) Powder for Injection in combination with REBETOL (ribavirin, USP) capsules demonstrates a correlation between the EVR and the success rate of a full, 48-week course of treatment, according to a paper published in Hepatology (1).
"A 12-week EVR provides patients and physicians with an early marker and, for the majority of patients who attain EVR, can help encourage patients to complete therapy," said Gary L. Davis, MD, director of the division of hepatology, Baylor University Medical Center, Dallas, and lead author of the paper. "On the other hand, for patients who do not demonstrate an EVR, physicians should consider discontinuing treatment," he said. Davis further explained that the 100 percent negative predictive value of the EVR to PEG-INTRON and REBETOL combination therapy can also help physicians make a decision regarding continuation of therapy.
As noted in the paper, 74 percent of patients demonstrated an EVR following 12 weeks of individualized, weight-based dosing of PEG-INTRON (1.5 ug/kg/week) and REBETOL (800 mg/day) combination therapy and, of those patients, 72 percent (positive predictive value) went on to achieve a sustained virologic response (SVR) after a full, 48-week course of treatment. EVR is defined as at least a 99 percent (2 log10) reduction in hepatitis C virus (HCV) load at week 12 of therapy. SVR, the accepted criterion for efficacy, is defined as the sustained undetectability of HCV six months following the end of treatment.
The paper also noted that, of the patients who failed to attain an EVR at 12 weeks, none achieved an SVR (100 percent negative predictive value). When cost was considered, it was estimated that discontinuing treatment in early non-responders could reduce total overall drug treatment costs nearly 20 percent.
"The findings by Dr. Davis and his team can be very helpful for clinicians making treatment decisions, especially when considered along with data on the rate of relapse," said Bruce R. Bacon, MD, director of the division of gastroenterology and hepatology, and professor of internal medicine at Saint Louis University School of Medicine, Missouri. Relapse is defined as the recurrence of HCV infection during the six-month follow-up period in a patient who had a virologic response at the end of treatment.
"Pegylated interferon therapies in combination with ribavirin have side effects and adherence can be difficult for some patients," Bacon said. "To help patients stay on treatment, a therapy that correlates 12-week response to 48-week sustained response can be important," he said.
PEG-INTRON and REBETOL combination therapy is the most prescribed treatment for hepatitis C worldwide and is indicated for the treatment of chronic hepatitis C in patients with compensated liver disease who have not been previously treated with interferon alpha and are at least 18 years of age. More than 300,000 hepatitis C patients worldwide, including 175,000 U.S. patients, have received this combination therapy since its introduction in 2001.
Schering-Plough, on Oct. 13, 2003, announced that the U.S. Food and Drug Administration (FDA) has granted marketing approval to PEG-INTRON REDIPEN pre-filled pen for administering PEG-INTRON, and the first and only pen delivery system approved for administering pegylated interferon therapy. The REDIPEN is designed to be simpler to use than a traditional vial and syringe, thus enhancing patient confidence with dosing of their PEG-INTRON regimen. PEG-INTRON REDIPEN is expected to be available in the United States in early 2004. It is currently available in the European Union (EU) and several other international markets.
PEG-INTRON, the only interferon product for hepatitis C approved for dosing according to body weight, uses proprietary PEG technology developed by Enzon, Inc. of Bridgewater, N.J. PEG-INTRON, recombinant interferon alfa-2b linked to a 12,000 dalton polyethylene glycol (PEG) molecule, is a once-weekly therapy that has been shown to exert both antiviral and immunomodulatory effects. Schering-Plough holds an exclusive worldwide license to PEG-INTRON. REBETOL is an oral formulation of the antiviral agent ribavirin, a synthetic nucleoside analog.
(1) Davis GL, Wong JB, McHutchison JG, Manns MP, Harvey J, Albrecht J.
Early virologic response to treatment with peginterferon alfa-2b plus
ribavirin in patients with chronic hepatitis C. Hepatology, Vol. 38,
No. 3, 2003, pp. 645-652.
Source: Schering-Plough Corporation