O-STA

Early Response to Individualised Weight-Based PegIntron(R) and Rebetol(R) Hepatitis C Therapy Allows Accurate Prediction of Treatment Success

BRUSSELS, BELGIUM (ots) -

80 Percent of Early Responders Achieve Sustained Response After Full 48-Week

Treatment

Early Response Can Motivate Patients to Complete Treatment

Early virologic response (EVR) in patients with chronic hepatitis C following

12 weeks of individualised, weight-based dosing of PegIntron(r) (peginterferon

alfa-2b) and Rebetol(r) (ribavirin) combination therapy can accurately predict

the likely outcome of a full, 48-week course of treatment, according to a paper

appearing in the current issue of Hepatology.(1) The findings show that EVR is

important to physicians in making treatment decisions and to patients as a

treatment milestone. This analysis is consistent with the current European Union

(EU) labeling for PegIntron.

As noted in the paper, 76 percent of patients demonstrated an EVR following

12 weeks of individualised, weight-based dosing of PegIntron and Rebetol

combination therapy, and, of those, 80 percent of patients went on to achieve a

sustained virologic response (SVR) after full treatment. EVR is defined as at

least a 99 percent (2 log10) reduction in hepatitis C virus (HCV) load at week

12 of therapy. SVR is defined as the sustained undetectability of HCV six months

following 48 weeks of treatment and is the accepted criterion for efficacy.

The paper also noted that, of the patients who failed to attain an EVR at 12

weeks, none achieved an SVR (100 percent negative predictive value). When cost

was considered, it was estimated that discontinuing treatment in early non-

responders could reduce total overall drug treatment costs nearly 20 percent.

"A 12-week EVR provides patients and physicians with an early goal, and, for

the majority of patients who attain EVR, can motivate treatment adherence and

completion to achieve a sustained virologic response," said Michael P. Manns,

M.D., professor, Department of Gastroenterology and Hepatology, Medical School

of Hannover, Germany. "On the other hand, as noted in the EU labeling for

PegIntron, for patients who do not demonstrate an EVR or take longer to respond

to therapy, physicians should consider discontinuing treatment or continuing it

based on other prognostic factors," he added.

Dr. Manns said that the positive predictive value of individualised, weight-

based dosing of PegIntron and Rebetol combination therapy in this study is very

encouraging in that, of those patients who achieved an EVR, 80 percent went on

to achieve an SVR. He also stated that the 100 percent negative predictive value

of this combination therapy indicates that physicians can predict, with a high

degree of confidence, which patients will not respond to further treatment, and

ensure that therapy is not prematurely discontinued for any potential

responders.

PegIntron and Rebetol combination therapy is the most prescribed treatment

for hepatitis C worldwide and is indicated for the treatment of chronic

hepatitis C in patients with compensated liver disease who have not been

previously treated with interferon alpha and are at least 18 years of age. More

than 300,000 hepatitis C patients worldwide, including 150,000 U.S. patients,

have received this combination therapy since its introduction in 2001.

About PegIntron and Rebetol Combination Therapy

PegIntron and Rebetol combination therapy for hepatitis C was approved in the

EU in March 2001. PegIntron had previously received centralized marketing

authorization in the EU and is marketed as a monotherapy in cases of intolerance

or contraindication to ribavirin for the treatment of adult patients with

chronic hepatitis C.

PegIntron is a longer-acting form of Intron(r) A (interferon alfa-2b,

recombinant) Injection that uses proprietary PEG technology developed by Enzon,

Inc. (NASDAQ: ENZN) of Bridgewater, N.J. PegIntron, recombinant interferon alfa-

2b linked to a 12,000 dalton polyethylene glycol (PEG) molecule, is a once-

weekly therapy dosed according to patient body weight that is designed to

achieve an effective balance between antiviral activity and elimination half-

life. Schering-Plough holds an exclusive worldwide license to PegIntron.

Rebetol is an oral formulation of ribavirin, a synthetic nucleoside analog

with broad-spectrum antiviral activity. It is approved worldwide for use in

combination with PegIntron or Intron A for the treatment of adult patients with

chronic hepatitis C. Schering- Plough has rights to market oral ribavirin for

hepatitis C in all major world markets through a licensing agreement with ICN

Pharmaceuticals, Inc. (NYSE: ICN) of Costa Mesa, Calif.

Schering-Plough Europe, based in Brussels, Belgium, is part of Schering-

Plough Corporation (NYSE: SGP) of Kenilworth, N.J., USA, a research-based

company engaged in the discovery, development, manufacturing and marketing of

pharmaceutical products worldwide.

Note to Editors: PegIntron and Rebetol are licensed to Aesca in Austria,

Essex Pharma in Germany and Essex Chemie in Switzerland.

References

(1) Davis GL, Wong JB, McHutchison JG, Manns MP, Harvey J, Albrecht J. Early

virologic response to treatment with peginterferon alfa-2b plus ribavirin in

patients with chronic hepatitis C. Hepatology, Vol. 38, No. 3, 2003, pp. 645-

652.