Bangkok--Aug 24--Weber Shandwick
ENTECAVIR EFFICACY AND RESISTANCE DATA PRESENTED AT ASIAN PACIFIC ASSOCIATION FOR THE STUDY OF THE LIVER (APASL) MEETING
Data from three studies presented today at the 15th Meeting of the Asian Pacific Association for the Study of the Liver (APASL) showed that the oral antiviral agent entecavir was superior or comparable to lamivudine in a wide variety of patients chronically infected with the hepatitis B virus (HBV). The study populations included patients with compensated liver disease who were: initiating antiviral treatment for the first time (nucleoside-naive); had received prior antiviral treatment (other than entecavir); and those who were refractory to lamivudine (defined as non-responsive, relapsed or resistant).
Results of another study showed that after one year of treatment, there was no evidence of resistance to entecavir in the nucleoside-naive, chronic hepatitis B patient group. Discovered at Bristol-Myers Squibb, entecavir is a nucleoside analog and a selective inhibitor of the hepatitis B virus.
“Most physicians consider the potential for emergence of resistance when deciding which antiviral to use for treating chronic hepatitis B patients,” said C. L. Lai, professor of Medicine & Hepatology; Chief, Division of Gastroenterology & Hepatology, Department of Medicine, the University of Hong Kong, Hong Kong SAR, China. “Today’s analysis of entecavir Phase III data showed that there was no evidence of emerging entecavir resistance after 48 weeks of treatment in any nucleoside-naive patients. Only 1 percent of lamivudine-refractory patients treated with entecavir exhibited virologic rebounds (or the reappearance of measurable virus levels) due to resistance.”
“Chronic hepatitis B is one of China’s most pressing health problems,” said Professor Jia JiDong, Capital University of Medical Sciences, Beijing Friendship Hospital, China. “I believe there is an urgent need for earlier diagnosis and treatment with effective medication to address some of the devastating long-term complications associated with chronic hepatitis B for people in our country.”
More than half a million people worldwide die each year from primary liver cancer, and up to 80 percent of primary liver cancers are caused by chronic hepatitis B virus. 1 Among the 400 million people who are chronically infected with this virus, 75 percent reside in Asia. 2 Primary liver cancer, or hepatocellular carcinoma (HCC), is among the top-three causes of cancer deaths in many Asian countries. 3
- China has the greatest burden of hepatitis B and liver cancer in the world, with an estimated 130 million individuals, or approximately 10 percent of the population, chronically infected. 2
- An estimated 360,000 deaths from hepatitis B virus infection occur each year in countries in Eastern Asia alone (China, Hong Kong, Japan, Korea). 4
- In India, it is estimated that one in 20 people is chronically infected with hepatitis B virus, with 1 percent of total deaths in adults in India due to hepatitis B virus. 5
- An estimated 6 percent of the Singaporean population, or approximately 250,000 people, are chronically infected with hepatitis B virus. 6
A 2005 update of the Asian-Pacific consensus statement on the management of chronic hepatitis B reports that sustained viral suppression is the key to the reduction or prevention of hepatic (liver-related) injury and disease progression, and the primary goal of treatment is to eliminate or permanently suppress hepatitis B virus.7
Phase III studies investigated the efficacy of entecavir in treating a variety of patients with chronic hepatitis B infection, including both hepatitis B e-antigen (HBeAg)-positive and HBeAg-negative nucleoside-naive patients and lamivudine-refractory patients. Patients who are HBeAg-positive exhibit deterioration of liver function, cirrhosis and liver cancer and account for 25 to 40 percent of patients who are chronically infected.6 Patients who are HBeAg-negative have disease characterized by a progressive course of severe liver damage with a poor long-term prognosis and frequent progression to cirrhosis and liver cancer.
Phase III data presented at APASL include:
- Study ETV-023, a double-blind, randomized Phase III clinical study of 519 patients, investigated the efficacy and safety of entecavir in nucleoside-naive adult patients in China with chronic hepatitis B. At Week 48, 90 percent of patients treated with 0.5 mg entecavir, compared to 67 percent treated with lamivudine, had reached the composite primary efficacy endpoint (HBV DNA below the limit of detection [0.7 MEq/mL by bDNA assay
] and ALT of less than 1.25 times the upper limit of normal). Data demonstrated that treatment with entecavir produced statistically significantly greater reductions in viral load compared to lamivudine at Week 48 (p