A multicenter study called WIN-R on Hepatitis C patients, showed that the treatment with weight-based drugs resulted in improved efficacy and lower relapse rates, mainly in African-Americans with most difficult-to-treat form of the disease.

The study of over 5,000 patients with hepatitis C virus (HCV) showed that the treatment with weight-based REBETOL (ribavirin, USP) (RBV) in combination with pegylated interferon (PEG-IFN) alfa-2b, resulted in higher rates of sustained virologic response (SVR) and lower relapse rates, as compared to combination therapy using a flat dose of RBV 800 mg/day.