| FDA 
Approves Dose Adjustments of PegIntron and Rebetol for Certain Patients with Chronic 
Hepatitis C  The 
U.S. Food and Drug Administration (FDA) last week announced approval of a new 
dosing regimens for certain patients taking pegylated 
interferon alfa-2b (PegIntron) plus ribavirin (Rebetol brand) for the treatment 
of chronic hepatitis C virus (HCV) infection.
 The 
package insert now specifies revised reduced doses of pegylated interferon and 
ribavirin to manage side effects such as blood cell deficiencies. These changes 
reflect findings from the IDEAL 
study, which indicated that lower doses of pegylated interferon could still 
be effective, but an adequate dose of ribavirin was needed to prevent relapse. Below 
is the FDA's announcement of the label change. | FDA 
Hepatitis Update -- Dose adjustments of PegIntron and Rebetol for certain 
patients with chronic hepatitis C
 On 
May 8, 2009, FDA approved updates to the package insert for PegIntron (peginterferon 
alfa-2b), a polyethylene glycol-conjugated formulation of interferon alfa-2b, 
currently approved for the treatment of chronic hepatitis C (HCV) in patients 
3 years of age and older with compensated liver disease, to reflect the results 
of the IDEAL study, P03471, which includes adding a two-step dose reduction scheme 
for PegIntron and increasing the dose of Rebetol to 1200 mg/day for patients who 
weigh between 81 and 85 kilograms. 
 The package insert for PegIntron has 
been revised to provide changes in the DOSAGE AND ADMINISTRATION section regarding 
the new two-step dose reduction for PegIntron in the event of poor tolerability 
or toxicity. Dose reduction recommendations include decreasing from PegInton 1.5 
mcg/kg/week to 1.0 mcg/kg/week, then to 0.5 mcg/kg/week if a second dose reduction 
is needed. In addition, dose recommendations for the accompanying dose of Rebetol 
in patients > 80 to 85 kg have been revised to 1200 mg daily rather than 1000 
mg daily. Study P03471 is described in the CLINICAL STUDIES section of the label.
 
 The IDEAL study compared PegIntron 1.5 mcg/kg/week and PegIntron 1.0 mcg/kg/week 
both in combination with Rebetol and Pegasys 
[pegylated interferon alfa-2a] 180 mcg/week in combination with Copegus [ribavirin] 
in 3070 treatment-naive subjects with genotype 1 HCV infection. Overall, sustained 
viral response (SVR) rates were similar in all three treatment arms, however, 
the PegIntron 1.5 mcg dose appeared to provide numerically higher sustained viral 
response (SVR) rates than the PegIntron 1.0 mcg dose in many hard-to-treat subgroups 
including African Americans, patients > 40 years of age, and patients with 
high viral load.
 
 The two-step approach to dose reduction appears to provide 
optimal efficacy in the greatest number of patients while preserving demonstrated 
efficacy of PegIntron 1.0 mcg/kg in those patients who require dose reduction 
because of intolerance or toxicity. A second dose reduction was required in a 
relatively small proportion of study subjects (2%-7% across the arms).
 
 The 
revised label will be available soon on the FDA web site at Drugs@FDA.
 
 Complete 
prescribing for PegIntron is available online at http://www.pegintron.com/peg.
 | 
 5/15/09 SourceR 
Klein and K Struble (Food and Drug Administration). FDA Hepatitis Update -- Dose 
adjustments of PegIntron and Rebetol for certain patients with chronic hepatitis 
C. May 12, 2009.
     
                                                           
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