In Largest U.S. Hepatitis C Trial, Researchers Determine Weight-Based Dosing is Key to Optimal Treatment

As reported recently in the journal Hepatology, WIN-R, a multicenter study of more than 5,000 patients with hepatitis C virus (HCV) showed treatment with weight-based REBETOL® (ribavirin, USP) (RBV) in combination with pegylated interferon (PEG-IFN) alfa-2b achieved significantly higher rates of sustained virologic response (SVR) and lower relapse rates compared to combination therapy using a flat dose of RBV 800 mg/day. Superior response was found particularly in patients with the most difficult-to-treat form of the disease, genotype 1 HCV. Efficacy was consistent across all weight groups.

For patients infected with genotype 2 or 3, a 24 week course of treatment with flat dose RBV + PEG-IFN was as effective as the standard 48-week course, with better tolerability, and in the overall study population flat dosing of ribavirin was as effective as weight-based ribavirin. However, within the flat-dose cohort of patients with genotypes 2 and 3, sustained response rates showed a slight decline in the higher weight patients given flat-dosed ribavirin.

"These findings help define optimal therapy for U.S. hepatitis C patients," says the study's principal investigator, Dr. Ira M. Jacobson, the Vincent Astor Professor of Clinical Medicine at Weill Cornell Medical College and chief of the Division of Gastroenterology and Hepatology at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. "Our findings underscore that weight-based-dosed combination therapy is significantly more effective than the flat-dosed RBV regimen, especially in more difficult-to-treat patient groups, such as patients with genotype 1 and African-American patients. Patients being treated for hepatitis C should talk to their doctors to be sure they are receiving the most effective therapy."

Reported in the same journal is a subanalysis of the WIN-R data that evaluates the efficacy of weight-based dosing among African-American participants with genotype 1 infection. Twice as many of these patients cleared the virus when treated with the weight-based RBV regimen vs. the flat dose (21 percent vs. 10 percent); a lower rate was shown in the general study population with genotype 1 HCV, 34 percent vs. 28.9 percent. (However, the fact that over 300 patients with an end of treatment response missed their 24-week, post-treatment follow-up appointment accounts for some treatment failures under a strict intent-to-treat analysis.)

"These results are particularly significant for African-Americans, a group with known lower rates of response to HCV therapy than reported in other ethnic groups. Weight-based dosing vs. flat dosing clearly showed the greatest therapeutic impact in this group," says Jacobson.

"The study data strongly suggest adopting a 1400 mg/dose for patients who weigh more than 105 kg. In my opinion, the larger dose provides an opportunity for very heavy patients to have the same chance of cure as lighter patients without compromising safety," says Jacobson.

Overall safety with weight-based dosing was similar to that of the flat 800 mg dose. There was no difference in the occurrence of serious adverse events in the entire group, as well as in the African-American group.

Researchers at NewYork-Presbyterian/Weill Cornell are at the forefront of developing more effective prescription therapy for patients with HCV genotype 1 and are testing many drugs in various stages of development.

Collaborating with the study's principal investigator Jacobson was Dr. Robert S. Brown Jr., co-principal investigator of the study and associate professor of clinical medicine at Columbia University College of Physicians and Surgeons; and chief of clinical hepatology and medical director of the Center of Liver Disease and Transplantation at NewYork-Presbyterian Hospital/Columbia University Medical Center.

Jacobson is also medical director of the Center for the Study of Hepatitis C in New York City, a unique interdisciplinary Center established jointly by The Rockefeller University, New York-Presbyterian Hospital, and Weill Cornell Medical College. He serves as a consultant, investigator and speaker for Schering-Plough.

Source: NewYork-Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College