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| |  DDW: More Patients With Chronic Hepatitis C Respond To Pegasys Than Interferon ORLANDO, FL -- May 17, 1999 -- Data presented today demonstrate that Hoffmann-La Roche Inc.’s Pegasys(TM) (peginterferon alfa-2a), an investigational, longer-lasting form of interferon, produces a sustained response in more patients than currently marketed interferon therapy in the treatment of chronic hepatitis C, a disease afflicting approximately four million people in the United States. The data were presented during the opening plenary session of Digestive Disease Week. The data from a controlled, randomised, multicentre Phase II trial found that 36 percent of patients treated with 180 mcg. of Pegasys experienced a sustained response of undetectable levels of hepatitis C virus (HCV) compared to three percent of patients treated with currently marketed interferon. Sustained response is measured at 24 weeks following a treatment period of 48 weeks. The presence of HCV was measured by the Roche Diagnostics Amplicor(R) HCV Test for which the company has initiated filing with the U.S. Food and Drug Administration. The study followed 155 non-cirrhotic, HCV-infected patients for a 48-week treatment period with a 24-week post-treatment follow-up. Patients were assigned to one of three groups receiving once-weekly doses of either 45 or 90 mcg., 180 mcg., or 270 mcg. of Pegasys. All three cohorts included control groups of patients receiving three million international units (MIU) of interferon three times per week. Response to treatment was measured at four-week intervals by levels of HCV-RNA and serum alanine aminotransferase (ALT), a liver enzyme. In the study, Pegasys was injected once a week, as compared to currently available interferon therapy, which must be injected three times a week. "Currently marketed interferon is cleared by the body very quickly with an approximate half-life of seven to ten hours. In this study, Pegasys has a half-life of approximately 100 hours, enabling it to remain in the body longer to fight the virus," said Mitchell Shiffman, MD, chief, hepatology section, Medical College of Virginia. In Phase II clinical trials adverse events with Pegasys appear to be similar to those seen with traditional interferon regimens, such as fatigue, headache, myalgia/arthralgia, flu-like symptoms, nausea/vomiting, injection site reactions, fever, chills, diarrhea, partial alopecia, abdominal pain, depression, irritability, insomnia, dizziness and anorexia. Although dose-dependent reduction of white blood cells is more frequent with Pegasys than currently marketed interferon, this does not appear to be related to an increased risk of infection. Pegylation is the process of attaching one or more hair-like strands of an inert, synthetic polymer called polyethylene glycol (PEG) to another molecule. The PEG attachment encircles the protein and disguises it from the human metabolic system. Pegylation provides a rapid and sustained delivery of this optimised interferon, changing its absorption characteristics and delaying its metabolism. Research shows that the length of the PEG strands attached to a molecule is directly related to the increase in a compound's half-life, therefore, the larger the PEG, the longer the half-life. Pegasys has a 40-kilodalton (40k) molecular weight. The 40K refers to the size of the PEG strand attached to interferon alfa. Using 40K PEG increases the half-life of interferon alfa from seven to 10 hours to approximately 100 hours. Hepatitis C, a blood-borne infectious disease of the liver, is a leading cause of cirrhosis and liver cancer and the number-one reason for liver transplants in the U.S. An estimated four million Americans are infected with the virus, with 35,000 to 180,000 new infections each year. In the U.S., the Centers for Disease Control and Prevention estimate that hepatitis C is responsible for 8,000 to 10,000 deaths per year and could increase to 38,000 by the year 2010, surpassing annual HIV/AIDS deaths. Hepatitis C is a blood-borne virus transmitted through body fluids, primarily blood or blood products and sharing needles. In many patients, the mode of transmission is unknown. Unfortunately, most people who are infected with hepatitis C are unaware of it because, like HIV, it may take years for symptoms to develop. In addition, it is estimated that as many as 40 percent of people with HIV may be co-infected with hepatitis C.
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