title: Response to higher dose of entecavir 1.0 mg daily in patients with partial response to entecavir 0.5 mg daily.
abstract: BACKGROUND
  Despite its high potency against hepatitis B virus (HBV), entecavir (ETV) 0.5 mg daily may not be sufficient to induce complete viral suppression in some patients with very high pretreatment viremia. It is not clear whether ETV 1.0 mg daily would have additive effect in such patients.
  
  
  OBJECTIVE
  Our goal was to examine virologic outcome of ETV 1.0 mg daily in patients with partial response to ETV 0.5 mg daily.
  
  
  METHODS
  We retrospectively studied 31 consecutive treatment-naive patients who were switched to ETV 1.0 mg daily after partial response [reduction of HBV DNA ≥2 log10 IU/mL but with detectable HBV DNA levels (>100 IU/mL) after 24 weeks of therapy or longer] with ETV 0.5 mg daily from January 2005 to January 2010 at 2 clinics.
  
  
  RESULTS
  All patients were Asians and 90% had positive hepatitis B e antigen. Mean HBV DNA was 8.04±0.65 log10 IU/mL before therapy and 3.64±0.91 log10 IU/mL at the time of switch. Overall rate of complete viral suppression were 29% (n=9/31) after 24 weeks of ETV 1.0 mg daily and 22% (n=5/23) after 48 weeks. Complete viral suppression after 24 weeks with ETV 1.0 mg daily was significantly higher in patients with lower HBV DNA (<3 log10 IU/mL) at time of switch: 75% versus 5%, P<0.0001.
  
  
  CONCLUSIONS
  The majority of patients with partial response to ETV 0.5 mg daily did not achieve complete viral suppression with the higher dose of ETV 1.0 mg daily except those with minimal residual viremia (HBV DNA <3 log10 IU/mL).
authors.affiliation: Division of Gastroenterology and Hepatology, Stanford University Medical Center, Palo Alto, CA 94304, USA.
authors.forename: Nghiem B
authors.initials: NB
authors.lastname: Ha
authors.forename: Nghi B
authors.initials: NB
authors.lastname: Ha
authors.forename: Huy N
authors.initials: HN
authors.lastname: Trinh
authors.forename: Huy A
authors.initials: HA
authors.lastname: Nguyen
authors.forename: Khanh K
authors.initials: KK
authors.lastname: Nguyen
authors.forename: Mindie H
authors.initials: MH
authors.lastname: Nguyen
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage*; D004279:DNA, Viral / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D019562:Viral Load / Q000187:drug effects*; D014766:Viremia / Q000188:drug therapy* / Q000821:virology; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006513:Hepatitis B e Antigens; C413685:entecavir; D006147:Guanine