Win-R Study: Ribavirin Weight-Base Dosing in High Weight Patients; Treatment Res

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Win-R Study: Ribavirin Weight-Base Dosing in High Weight Patients;

Treatment Responses to PegIntron/RBV for Elderly Patients and by

Patient Ethnicity

“New Data from Largest U.S. Hepatitis C Trial Provide Insights Into

Optimizing Treatment for Patient Populations Traditionally Considered

Difficult to Treatâ€

October 31, 2006 - 5:58 AM

Source: NewYork-Presbyterian/Weill Cornell Medical Center

Community-Based WIN-R Study Shows Significantly Better Outcomes with

Weight-Based Dosing

BOSTON, Oct. 30 /PRNewswire/ -- New data from the WIN-R trial, the

largest hepatitis C study ever conducted in U.S. patients, provide

important insights into optimizing treatment with peginterferon alfa-

2b (PEG-INTRON®, Schering-Plough) and ribavirin (REBETOL®,

Schering-Plough) combination therapy in patient populations

traditionally considered difficult to treat. Researchers evaluated

results in specific patient groups to determine if characteristics

such as age, ethnicity, body weight, hepatitis C genotype and viral

load were independent predictors of response or medication

tolerability. The findings were reported in four separate

presentations here at the 57th Annual Meeting of the American

Association for the Study of Liver Diseases (AASLD).

" These WIN-R findings help us better understand how to optimize

hepatitis C treatment for the different types of patients we see

everyday in community practice, " said principal investigator Ira M.

son, M.D., 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 in New York City. " These

results, in the large number of patients who participated in this

study, provide a wealth of information that physicians can use with

confidence to help improve treatment outcomes in their hepatitis C

patients. "

WIN-R (Weight-Based Dosing of PEG-INTRON and REBETOL) was a community-

based trial involving more than 4,900 patients at 225 centers across

the United States. As reported last year at AASLD,(1) the study

showed peginterferon alfa-2b, in combination with weight-based

ribavirin, resulted in better outcomes compared to flat-dosed

ribavirin, including significantly higher rates of sustained

virologic response (SVR) overall.(2) SVR is the standard measure of

treatment success.

New WIN-R Data at AASLD 2006

-- Patient weight (Dr. Ira son and colleagues).(3) Historically,

studies have shown that heavier patients with hepatitis C virus (HCV)

infection are less likely to achieve an SVR with antiviral therapy.

(4) Results of the WIN-R study, however, showed that patients treated

with peginterferon alfa-2b and weight-based ribavirin achieved

consistent rates of SVR regardless of body weight. Even obese

patients (those weighing 125 kg [275 lbs] or more) achieved SVR rates

similar to all other patients in the study (45% vs. 44%) [with 1400

mg ribavirin]. The heavier patients in WIN-R were much more likely to

achieve an SVR with weight-based ribavirin than with flat-dosed

ribavirin (64% vs. 25%). Obese patients also showed low rates of

anemia, neutropenia and dose reductions, probably reflecting lower

levels of ribavirin exposure with their larger body size. The authors

concluded that obesity alone should not preclude consideration for

hepatitis C treatment with peginterferon alfa-2b plus weight-based

ribavirin.

-- Elderly patients (Dr. Flamm and colleagues).(5) Little data

are available on how age affects the response to interferon-based

therapies for hepatitis C because patients older than age 65 are

ineligible for most clinical trials. This study showed that, while

young adults age 18-25 years (n=69) were more likely than any other

age group to achieve an SVR (57%), patients older than 65 (n=55) had

a similar rate of SVR compared to all other age groups (46% vs. 44%,

respectively). Although there were more adverse events among the

older patients, the rate of serious adverse events and treatment drop-

outs were the same or less than in the younger age groups. The

authors concluded that older patients should not be denied access to

hepatitis C therapy with peginterferon alfa-2b plus ribavirin based

upon age alone.

-- Patient ethnicity (Dr. Bradley Freilich and colleagues).(6) Past

studies with standard interferon plus ribavirin therapy suggest that

ethnic origin may be an important predictor of response, with SVR

rates highest in Asian patients (61%), followed by Caucasian (39%),

Hispanic (23%), and African-American (14%) patients.(7) The WIN-R

study included the largest dataset in Hispanic patients reported to

date, and the results confirm that hepatitis C is challenging to

treat in this population. Rates of SVR were significantly lower in

Hispanic patients compared to Asian patients and Caucasian patients:

34% vs. 52% (p=0.0002) and 46% (p=0.0057), respectively. Among

Hispanic patients, the best results were seen in those with hepatitis

C genotype 2 or 3 and low baseline viral load who were treated with

peginterferon alfa-2b plus weight-based ribavirin. Additional studies

are required to identify factors that will improve SVR rates in this

ethnic group.

-- Patients with HCV genotype 3 high viral load (Dr. Brown and

colleagues).(8) Patients with HCV genotype 2 or 3 (G2 or G3)

generally respond better to treatment than patients with genotype 1,

(9) and most studies have reported treatment responses in G2 and G3

patients as a single group. In WIN-R, these responses were examined

separately, and showed that G2 patients achieved higher SVR rates

(66% vs. 55%, p<0.0001) and lower relapse rates compared to G3

patients. G3 patients with high baseline viral load were more likely

to relapse. While these findings suggest higher doses of ribavirin

may benefit patients with hepatitis C genotype 3, additional research

is needed to define the optimal strategy for lowering relapse rate in

these patients.