title: Monotherapy with tenofovir disoproxil fumarate for multiple drug-resistant chronic hepatitis B: 3-year trial.
abstract: Combination therapy has been recommended for the treatment of patients harboring multiple drug-resistant hepatitis B virus (HBV). However, we recently demonstrated that monotherapy with tenofovir disoproxil fumarate (TDF) for 48 weeks displayed noninferior efficacy to TDF plus entecavir (ETV) combination therapy in patients with HBV resistant to multiple drugs, including ETV and adefovir. Nonetheless, whether prolonged TDF monotherapy would be safe and increase the virologic response rate in these patients was unclear. Among 192 patients with HBV-resistance mutations to ETV and/or adefovir, who were randomized to receive TDF monotherapy (n = 95) or TDF/ETV combination therapy (n = 97) for 48 weeks, 189 agreed to continue TDF monotherapy (TDF-TDF group) or to switch to TDF monotherapy (TDF/ETV-TDF group) and 180 (93.8%) completed the 144-week study. Serum HBV DNA <15 IU/mL at week 48, the primary efficacy endpoint, was achieved in 66.3% in the TDF-TDF group and 68.0% in the TDF/ETV-TDF group (P = 0.80). At week 144, the proportion with HBV DNA <15 IU/mL increased to 74.5%, which was significantly higher compared with that at week 48 (P = 0.03), without a significant difference between groups (P = 0.46). By on-treatment analysis, a total of 79.4% had HBV DNA <15 IU/mL at week 144. Transient virologic breakthrough occurred in 6 patients, which was due to poor drug adherence. At week 144, 19 patients who had HBV DNA levels >60 IU/mL qualified for genotypic resistance analysis, and 6 retained some of their baseline resistance mutations of HBV. No patients developed additional resistance mutations throughout the study period.
  
  
  
  TDF monotherapy was efficacious and safe for up to 144 weeks, providing an increasing rate of virologic response in heavily pretreated patients with multidrug-resistant HBV. (Hepatology 2017;66:772-783).
authors.affiliation: Department of Gastroenterology, Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Young-Suk
authors.initials: YS
authors.lastname: Lim
authors.affiliation: Department of Gastroenterology, Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yung Sang
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Geum-Youn
authors.initials: GY
authors.lastname: Gwak
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Byun
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yoon Jun
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Gastroenterology, Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jonggi
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Gastroenterology, Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jihyun
authors.initials: J
authors.lastname: An
authors.affiliation: Department of Gastroenterology, Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Han Chu
authors.initials: HC
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000187:drug effects; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D061214:Patient Safety / Q000706:statistics & numerical data; D016032:Randomized Controlled Trials as Topic; D056910:Republic of Korea; D012720:Severity of Illness Index; D000068698:Tenofovir / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome; D019562:Viral Load / Q000187:drug effects; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; C413685:entecavir; D006147:Guanine; D000068698:Tenofovir