Entecavir (Baraclude) and adefovir (Hepsera) are arguably the most potent anti-HBV agents currently approved by the U.S. Food and Drug Administration (FDA).

Baraclude Tablet

Hepsera Tablet

At the 43rd annual meeting of the European Association for the Study of the Liver (EASL) last month in Milan, researchers revealed 96-week extended-dosing results from the E.A.R.L.Y. study.

Prior results from weeks 12 and 42 of this randomized, open-label, comparative study in HBeAg+ chronic hepatitis B patients showed superior early reduction of HBV DNA with entecavir versus adefovir.

The E.A.R.L.Y. study enrolled 69 HBeAg+) antiviral-naive, chronic hepatitis B patients who were randomized 1:1 to receive either entecavir (0.5 mg) or adefovir (10 mg) once daily for a minimum of 52 weeks, at which time a clinical management decision was made.

Protocol-defined responders (HBe seroconversion and HBV DNA < 10,000 copies/mL for 24 weeks with last HBV DNA < 300 copies/mL) discontinued therapy and were observed off treatment. All other patients were to continue for a second year of treatment.

Measurements of serum HBV DNA by polymerase chain reaction, HBV serology and laboratory safety measurements were obtained through Week 96. The difference in reduction of HBV DNA at Week 96 is based on a linear regression model adjusted for baseline.

The results are shown in the Table:

ETV = entecavir
ADV = adefovir

Based on these findings, the investigators concluded that entecavir treatment resulted in a greater decrease from baseline in HBV DNA than adefovir through Week 96, with more patients achieving < 300 copies/mL HBV DNA. In addition, they reported that a higher proportion of patients discontinued adefovir (44%) than entecavir (12%). Both treatments were well tolerated overall, they noted.

Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China; China Medical University, Taichung, Taiwan; Santo Tomas University Hospital, Manila, Philippines; Cipto Mangunkusumo National Central General Hospital, Jakarta, Indonesia; Queen Mary Hospital, Pok Fu Lam, Hong Kong, China; University of Miami Center for Liver Diseases, Miami, Florida, USA; Liver Disease Prevention Center, Division of Gastroenterology and Hepatology, Thomas Jefferson University Hospital, Philadelphia, USA; Toronto General Hospital, Toronto, Canada; Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, CT, USA.

5/06/08

Reference
N Leung, CY Peng, J Sollano, and others. Entecavir (entecavir) results in higher HBV DNA reduction versus adefovir (adefovir) in antiviral-naive HBeAg(+) adults with high HBV DNA: week 96 results (E.A.R.L.Y. Study). 43rd Annual Meeting of the European Association for the Study of the Liver (EASL 2008). Milan, Italy. April 23-27, 2008.