Efficacy of entecavir with or without tenofovir disoproxil fumarate for nucleos(t)ide-naïve patients with chronic hepatitis B.
OBJECTIVE
Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent antiviral agents that might have additive or synergistic antiviral activity in treatment of patients with chronic hepatitis B (CHB). We compared the efficacy and safety of ETV monotherapy with those of a combination of ETV and TDF.


METHODS
We performed a randomized, open-label, multicenter, superiority study of 379 nucleos(t)ide-naïve patients with hepatitis B e antigen (HBeAg)-positive (n = 264) or HBeAg-negative (n = 115) CHB. Subjects were given ETV 0.5 mg (n = 182) or a combination of ETV 0.5 mg and TDF 300 mg (n = 197) for 100 weeks.


RESULTS
At week 96, comparable proportions of patients in each study arm achieved the primary end point of a level of hepatitis B virus (HBV) DNA <50 IU/mL (83.2% vs 76.4%; P = .088). Among HBeAg-positive patients, a greater proportion given combination therapy achieved levels of HBV DNA <50 IU/mL than those given ETV alone (80.4% vs 69.8%; P = .046). However, this difference was observed only in patients with baseline levels of HBV DNA ≥ 10(8) IU/mL (79% vs 62%) and not in those with baseline levels of HBV DNA <10(8) IU/mL (83% in both arms). Rates of HBeAg loss and HBeAg seroconversion were comparable between groups, whereas the rate of alanine aminotransferase normalization was greater in the ETV monotherapy group. No HBV variants associated with ETV or TDF resistance were detected. Safety profiles were consistent with previous reports of ETV or TDF monotherapy.


CONCLUSIONS
The antiviral efficacy of ETV monotherapy is comparable to that of ETV plus TDF in a mixed population of nucleos(t)ide-naïve patients with CHB (70% HBeAg positive). The combination therapy could provide an incremental benefit to HBeAg-positive patients with baseline levels of HBV DNA ≥ 10(8) IU/mL.
Division of Gastroenterology, University of Michigan Health System, Ann Arbor, Michigan. Electronic address: aslok@umich.edu.
Anna S
AS
Lok
Pacific Health Foundation, San Jose, California.
Huy
H
Trinh
Institute of Infectious and Tropical Disease, University of Brescia, Brescia, Italy.
Giampiero
G
Carosi
Department of Gastroenterology, Faculty of Medicine, Ege University, Izmir, Turkey.
Ulus S
US
Akarca
Sección Hepatología, Hospital Italiano de Buenos Aires-Argentina, Ciudad de Buenos Aires, Argentina.
Adrian
A
Gadano
Service d'Hépato-gastroentérologie, Nouvel Hôpital Civil, INSERM Unité 748, Université de Strasbourg, Strasbourg, France.
François
F
Habersetzer
Department of Medicine, Monash University, Monash Medical Centre, Melbourne, Australia.
William
W
Sievert
Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
David
D
Wong
Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut.
Meghan
M
Lovegren
Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut.
David
D
Cohen
Research and Development, Bristol-Myers Squibb Company, Wallingford, Connecticut.
Cyril
C
Llamoso
D000225:Adenine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D004279:DNA, Viral / Q000097:blood; D024882:Drug Resistance, Viral; D004359:Drug Therapy, Combination; D006147:Guanine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D016014:Linear Models; D063065:Organophosphonates / Q000009:adverse effects / Q000627:therapeutic use*; D010757:Phosphorous Acids; D013997:Time Factors; D016896:Treatment Outcome; D019562:Viral Load
C574165:9-(2-((bis(pivaloyloxymethoxy)phosphinoyl)methoxy)propyl)adenine; D000998:Antiviral Agents; D015415:Biomarkers; D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D063065:Organophosphonates; D010757:Phosphorous Acids; C413685:entecavir; D006147:Guanine; D000410:Alanine Transaminase; D000225:Adenine