Dec 28 2007
As reported recently in the journal Hepatology, WIN-R, a multicenter study of over 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% vs. 10%); a lower rate was shown in the general study population with genotype 1 HCV, 34% vs. 28.9%. (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 Dr. 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 Dr. 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 Dr. 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.
Dr. 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.
WIN-R Study
WIN-R (Weight-Based Dosing of PEG-INTRON and REBETOL) is a community-based access trial involving more than 5,000 patients at 225 centers across the U.S.
The uniquely large database of the WIN-R study allowed investigators to address other questions of interest, which have been presented at international meetings, including analyses of the response to HCV therapy based on age, baseline viral load, degree of liver fibrosis (scarring), and the study site at which the medication was delivered.
WIN-R is an investigator-initiated clinical study supported by Schering-Plough Corporation and monitored by Schering-Plough Research Institute as part of a post-marketing commitment to the U.S. Food and Drug Administration (FDA). PEG-INTRON and REBETOL are registered trademarks of Schering-Plough.
Hepatitis C
Hepatitis C is the most common blood-borne infection in America. It affects approximately 4 million people, or about one in every 50 adults, including a disproportionately high percentage of African-Americans. Chronic hepatitis C can cause cirrhosis, liver failure and liver cancer. It has been estimated that at least 20 percent of patients with chronic hepatitis C develop cirrhosis, and a smaller percentage of patients with chronic disease develop liver cancer. Patients with chronic hepatitis C and related cirrhosis are 100 times more likely to develop liver cancer than uninfected persons. About half of all cases of primary liver cancer in the developed world are caused by hepatitis C, and hepatitis C–related liver disease is now the leading cause for liver transplants.