BARACLUDE(R) (entecavir) Demonstrated Greater Antiviral Efficacy Compared To Adefovir In New Study Of Chronic Hepatitis B Patients With Cirrhosis

Main Category: Liver Disease / Hepatitis
Article Date: 03 Nov 2009 - 4:00 PST

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Bristol-Myers Squibb (NYSE: BMY) today announced 48-week data from an ongoing study (ETV-048) of chronic hepatitis B patients with decompensated cirrhosis, in which BARACLUDE demonstrated greater viral suppression compared to adefovir. The new BARACLUDE data were presented today at the 60th Annual Meeting of the American Association for the Study of Liver Diseases.

Decompensated cirrhosis is characterized by severe scarring of the liver caused by chronic liver inflammation, including inflammation associated with chronic hepatitis B infection. It is estimated that 15 to 25 percent of chronic hepatitis B patients die from complications of liver disease.1 Currently, the median survival rate in decompensated patients is two to three years, with only 28 percent of patients surviving for more than five years.2,3 The treatment of chronic hepatitis B patients with decompensated cirrhosis remains an area of unmet medical need, and these patients often require liver transplant.

"This study represents an important first step in addressing an unmet medical need, as this is one of the first comparative studies to evaluate the safety and efficacy of antiviral therapy in this difficult-to-treat patient population," said Professor Hugo Cheinquer, ETV-048 study investigator and associate professor of gastroenterology and hepatology, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil. "Chronic hepatitis B is a lifelong disease and these data suggest that treatment with BARACLUDE may offer chronic hepatitis B patients with decompensated cirrhosis a treatment option."

Study Results through Week 48

The primary study endpoint of ETV-048 was the mean change from baseline HBV DNA at Week 24, analyzed by linear regression and adjusted for baseline HBV DNA and lamivudine resistance status. The study successfully met its primary objective; at Week 24, BARACLUDE achieved a greater reduction in viral load than adefovir: -4.48 (0.200) versus -3.40 (0.251) log copies/mL, respectively (p < 0.0001).

A statistically significant difference was observed in the proportion of patients achieving undetectable viral load [HBV DNA <300 copies/mL as measured by polymerase chain reaction (PCR)] and ALT normalization. At 24 weeks, 49 percent (49/100) of patients treated with BARACLUDE® (entecavir) achieved an undetectable viral load, compared with 16 percent (15/91) of patients who received adefovir; at 48 weeks, 57 percent (57/100) of patients on BARACLUDE achieved an undetectable viral load, compared with 20 percent (18/91) of patients on adefovir (p< 0.0001). Also, among patients with baseline abnormal ALT, a higher proportion of BARACLUDE-treated patients achieved ALT normalization at Weeks 24 and 48 [59 percent (46/78) and 63 percent (49/78) respectively, compared with 39 percent (28/71) and 46 percent (33/71) of adefovir-treated patients].

Additionally, of the 100 patients treated with BARACLUDE, 66 percent had an improvement or no worsening of the Child-Pugh Score (which assesses severity of hepatic decompensation), with 32 percent of patients having achieved a ≥ 2-point reduction in Child-Pugh score at Week 24; these rates were 61 percent and 35 percent, respectively, at Week 48. Findings at Weeks 24 and 48 were comparable for patients receiving adefovir; 71 percent saw an improvement or no worsening of the Child-Pugh Score and 24 percent achieved a ≥ 2-point reduction in Child-Pugh score at Week 24; these rates were 67 percent and 27 percent, respectively, at Week 48. Patients treated with BARACLUDE also experienced an improvement of the Model for End-Stage Liver Disease (MELD) Score (another scoring system that assesses severity of hepatic decompensation). The change from baseline for patients treated with BARACLUDE was a decrease of 2.6 points compared with 1.7 points for patients treated with adefovir at Week 48.

The overall safety profile was comparable across the two treatments. As might be expected in this patient population, the overall incidence of adverse events was high with 89 percent (91/102) for the BARACLUDE arm and 97 percent (86/89) for the adefovir arm. Serious adverse events occurred in 69 percent (70/102) and 66 percent (59/89) of BARACLUDE- and adefovir-treated patients, respectively. Rates for death and hepatocellular carcinoma (HCC) were comparable. Overall, 23 percent (23/102) of BARACLUDE-treated patients died compared with 33 (29/89) percent of adefovir-treated patients. HCC occurred in 12 percent (12/102) of the BARACLUDE® (entecavir) arm compared with 20 (18/89) percent of the adefovir arm. Renal function was monitored for all patients. Increases in serum creatinine levels of ≥0.5 mg/dL from baseline were observed in 17 percent (17/102) of BARACLUDE-treated and 24 percent (21/89) of adefovir-treated patients.

About Study ETV-048

Study ETV-048 is a randomized, open-label, comparative Phase IIIb study of BARACLUDE compared to adefovir in treatment-naïve and lamivudine-experienced patients with chronic hepatitis B infection and decompensated cirrhosis (Child-Pugh score ≥ 7). The 195 adult patients (191 treated) were HBeAg-positive or HBeAg-negative, and nucleos(t)ide-naïve or lamivudine pre-treated.

Patients were randomized to receive BARACLUDE 1 mg or adefovir 10 mg daily and were treated for a minimum of 96 weeks. Baseline patient populations were comparable in the two treatment arms. Patients had a mean MELD score of 17 and 15, respectively, in the BARACLUDE and adefovir treatment groups. Approximately one third of patients were previously exposed and resistant to lamivudine.

The primary study endpoint was the mean change from baseline HBV DNA at Week 24, analyzed by linear regression and adjusted for baseline HBV DNA and lamivudine resistance status.

Secondary study endpoints specific to measuring improvement in cirrhosis included the MELD Score, an exam which scores patients on the severity of chronic liver disease, and the Child-Pugh Score (greater than or equal to a two-point decrease), which were evaluated at baseline, Week 24 and Week 48.

About Chronic Hepatitis B

Chronic hepatitis B is a serious global health issue. Worldwide, more than 2 billion people have been in contact with the hepatitis B virus and approximately 350 million people are chronically infected. 4

References

1. NHS Choices. Complications of hepatitis B. Available here. Accessed 15 September 2009

2. D'Amico G, Garcia-Tsao G, Pagliaro L. Natural history and prognostic indicators of survival in cirrhosis: a systematic review of 118 studies. J. Hepatol. 2006; 44: 217-31. 7 Ginés P, Quintero E, Arroyo V et al. Compensated cirrhosis: natural history and prognostic factors. Hepatology 1987; 7: 122-8.

3. Fattovich G, Pantalena M, Zagni I et al. Effect of hepatitis B and C virus infections on the natural history of compensated cirrhosis: a cohort study of 297 patients. Am. J. Gastroenterol. 2002; 97: 2886-95.

4. World Health Organization Web site. Fact sheet N°204. http://www.who.int/mediacentre/factsheets/fs204/en. Accessed August 28, 2009.

Source
Bristol-Myers Squibb