Early Treatment Is Indicated for Patients with Chronic Hepatitis C Regardless of Body Weight

Several recent studies have evaluated the influence of body weight on response to interferon-based therapy for hepatitis C. The present analysis, reported at the recent 58th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD 2007) in Boston (November 2-6, 2007), examined the impact of body weight on sustained virological response (SVR) rates in chronic hepatitis C patients who received weight-based pegylated interferon alfa-2b (PegIntron) plus weight-based ribavirin in the Canadian Peginterferon alfa-2b Prospective Optimal Weight-based Dosing Response (POWeR) program.

POWeR was an open-label, observational trial conducted in academic and community clinics across Canada between 2002 and 2006. The study included 1977 treatment-naive patients: 60% with HCV genotype 1, 22% with genotype 3, 15% with genotype 2, and 3% with genotype 4/5/6 or no specified genotype initiated treatment with PegIntron (1.5 mcg/kg/week) plus weight-based ribavirin (800-1200 mg/day) for either 24 week (genotype 2 or 3) or 48 weeks (genotype 1). SVR was defined as undetectable HCV RNA 24 weeks post-treatment. SVR rates were stratified by weight category, genotype, and fibrosis score.

Patients were excluded from analysis if they had undetectable HCV RNA at end of treatment but no 6-month follow-up data, had no treatment data, or had HIV-HCV coinfection. The 1800 subjects in this analysis included those who discontinued therapy because of side effects, lack of response, or personal reasons.

Results

·         Liver biopsy specimens, available for 946 patients (53%), demonstrated varying degrees of fibrosis: 60% with absent to moderate (stage F0-F2) and 40% with advanced fibrosis or cirrhosis (stage F3-F4).

·         There was no significant difference in fibrosis score or genotype distribution across weight categories.

·         There was a trend toward a higher incidence of F3-F4 fibrosis or cirrhosis in heavier patients.

·         No statistically significant differences in overall SVR rate, SVR by genotype, or SVR by fibrosis score were observed among weight categories (see table).

·         Overall SVR rates were higher in persons with F0-F2 fibrosis than in those with F3-F4 fibrosis or cirrhosis (60% vs 35%; P < 0.001).

 
Consistency of SVR Rates Across Weight Categories

*4 patients no weight data; 16 no genotype data.

In conclusion, the researchers wrote, “In this large, mixed academic- and community-based observational study, SVR rates were consistent regardless of weight category when individuals were dosed with weight-based pegylated interferon alfa-2b (1.5 mcg/kg/wk) and ribavirin (800-1200mg/day).”

“Patients with low fibrosis scores had high SVR rates, they added, leading them to recommend that, “Early treatment is indicated regardless of patient weight.”

Liver Study Unit, Mount Sinai Hospital, Toronto, ON, Canada; University of Western Ontario, London, ON, Canada; Hamilton Health Sciences General Site, Hamilton, ON, Canada; Ottawa Hospital-Civic Campus, Ottawa, ON, Canada; Hopital Notre-Dame du CHUM, Montreal, QC, Canada; Victoria B.C., Victoria, BC, Canada; Schering-Plough Canada Inc, Pointe Claire, QC, Canada; London Health Sciences Centre, London, ON, Canada.

11/09/07

Reference
SV Feinman, C Ghent, HB Witt-Sullivan, and others. Consistency of Sustained Virologic Response (SVR) Across Weight Categories: Results From the Canadian POWeR (Peginterferon alfa-2b Prospective Optimal Weight-based Dosing Response) Program. 58th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD 2007). Boston, MA. November 2-6, 2007. Abstract (poster) 302.