Sustained Virological Response to PegIntron Plus Ribavirin in Asian and Hispanic Patients

Retrospective examination of available data strongly suggests that Asian patients experience a higher rate of sustained virological response (SVR) to interferon plus ribavirin therapy for chronic hepatitis C compared with Caucasian patients, while Hispanic patients have a lower SVR than Caucasians. It is well established that African-American patients have poorer response than other racial/ethnic groups.

In the current study, presented at the 57th AASLD annual meeting taking place this week in Boston, researchers at 17 U.S. medical centers* evaluated SVR rates in Asian and Hispanic patients with chronic hepatitis C enrolled in the WIN-R trial, a large U.S. multicenter study comparing fixed dose (FD) vs weight based dosing (WBD) of ribavirin combined with pegylated interferon alfa-2b (PegIntron).

Patients were randomized to receive PegIntron 1.5 mcg/kg once weekly combined with ribavirin 800 mg (FD) or 800-1400 mg/day (WBD). Treatment was for 48 weeks, with 24 weeks follow-up.

The SVR rate was based on intent-to-treat (ITT) analysis and defined as undetectable HCV RNA by central quantitative TaqMan assay (lower limit of detection < 29 IU/mL or 100 copies/mL) 24 weeks after the completion of treatment.

Dose reductions of ribavirin were required for hemoglobin (Hgb) levels < 10 g/dL and discontinuation for Hgb < 8.5. Erythropoietin (EPO) was permitted concomitant with ribavirin dose reduction for Hgb < 10.

Results

	Approximately 5000 patients were randomized in this trial.
	The present report concerns 65 Asian patients (genotype 1=37; genotypes 2/3=25) and 251 Hispanic patients (genotype 1=166; genotype 2/3=77) who received at least 1 dose of ribavirin and were ? 65 kg.
	Of the 65 Asians, 34 (52.3%) achieved SVR vs 45.7% of Caucasians (P = 0.29). " SVR rate for Asians with genotype 1 was 15 of 37 (40.5%) vs 34.9% of Caucasians (P = 0.48).
	SVR rate for Asians with genotype 2/ 3 was 18 of 25 (72%) vs 61.6% of Caucasians (P = 0.29).
	SVR rate for Asians receiving ribavirin WBD was 21 of 32 (66%) vs 13 of 33 (39%) who received ribavirin FD (P = 0.04).
	Of the 251 Hispanic patients, 84 (33.5%) achieved SVR vs 45.7% of Caucasians (P = 0.0002)
	Hispanics were 1.7 times less likely to achieve SVR than Caucasians.
	SVR rate for 159 Hispanics who finished a full course of treatment was 46.5% vs 55.3% for Caucasians (P = 0.0006).
	SVR for Hispanics with genotype 1 was 44 of 166 (24.1%) vs 34.9% for Caucasians (P = 0.005).
	SVR for Hispanics with genotype 2/3 was 41 of 77 (53.6%) vs 61.6% for Caucasians (P = 0.14).
	SVR for Hispanics receiving ribavirin WBD was 39 of 122 (32%) vs 45 of 129 (35%) receiving ribavirin FD (P = 0.6).

Conclusion

Based on these findings, the authors concluded, "Compared to Caucasian patients, [PegIntron] 1.5 mcg/kg results in a significantly lower SVR for Hispanic patients by ITT analysis and for those who completed therapy."

They added that, "SVR for Asian patients vs Caucasian patients trended higher, but was not statistically significant."

This study was supported by Schering-Plough Corp.

*Baptist Medical Center, Kansas City, MO; University of California Irvine, Orange, CA; Weill Cornell Medical College, New York, NY; Columbia Presbyterian Medical Center, New York, NY; Beth Israel Deaconess Medical Center, Boston, MA; Indiana University School of Medicine, Indianapolis, IN, USA; Atlantic Gastroenterology Associates, PA, Egg Harbor Township, NJ; Austin Gastroenterology, Austin, TX; East Bay Liver Clinic, San Francisco, CA; Indianapolis Gastrointestinal Research Foundation, Indianapolis, IN; Bach and Godofsky, MD PA, Bradenton, FL; Northwest Georgia Gastroenterology Associates, PC, Marietta, GA; North Shore Long Island Jewish Health System, Manhasset, NY; Northwestern University, Chicago, IL; Gastroenterology Consultants, PA, Houston, TX; Albert Einstein Medical Center, Philadelphia, PA; Schering-Plough Research Institute, Kenilworth, NJ;

B Freilich, K Hu, I Jacobson, and others. Prospective Analysis of Sustained Virologic Response (SVR) to Peg-interferon (PEG IFN) Alfa-2b and Ribavirin Treatment in Asian and Hispanic Patients with Chronic Hepatitis C: Results from the WIN-R Trial. 57th AASLD. October 27-31, 2006. Boston, MA. Abstract 349.