Study to Evaluate the Safety and Efficacy of Switching to Tenofovir Alafenamide (TAF) From Tenofovir Disoproxil Fumarate (TDF) and/or Other Oral Antiviral Treatment (OAV)

• TAF (Drug), also known as Vemlidy®: Tablet administered orally once daily

Primary outcomes

• Percentage of Participants Achieving Virologic Response (Plasma Hepatitis B Virus [HBV] Deoxyribonucleic Acid [DNA] < 20 IU/mL) at Week 24 [Week 24]: The percentage of participants with HBV DNA < 20 IU/mL at Week 24 was determined by the Missing = Failure (M = F) approach.
• Percentage of Participants Who Experienced Graded Treatment-Emergent Adverse Events (AEs) at Week 24 [Week 24]: Treatment-emergent AEs were defined as: * Any AEs with an onset date on or after the study drug start date and no later than the study drug stop date + 3 days after permanent discontinuation of study drug; * Any AEs with onset date on or after the study drug start date for those who have not permanently discontinued study drug; * Any AEs leading to premature discontinuation of study drug. The most severe graded AE from all tests was counted for each participant.
• Percentage of Participants Who Experienced Graded Treatment-Emergent Laboratory Abnormalities at Week 24 [Week 24]: Graded treatment-emergent laboratory abnormalities were defined as values that increased at least 1 toxicity grade from baseline at any postbaseline visit, up to and including the date of last dose of study drug + 3 days for participants who permanently discontinued study drug or the last available date in the database snapshot for participants who were on treatment at the time of the analysis. The most severe graded abnormality from all tests was counted for each participant.

Secondary outcomes

• Percentage of Participants Who Experienced Graded Treatment-Emergent AEs at Week 48 [Week 48]: Treatment-emergent AEs were defined as: Any AEs with an onset date on or after the study drug start date and no later than the study drug stop date + 3 days after permanent discontinuation of study drug; Any AEs with onset date on or after the study drug start date for those who have not permanently discontinued study drug; Any AEs leading to premature discontinuation of study drug. The most severe graded AE from all tests was counted for each participant.
• Percentage of Participants Who Experienced Graded Treatment-Emergent AEs at Week 96 [Week 96]: Treatment-emergent AEs were defined as: Any AEs with an onset date on or after the study drug start date and no later than the study drug stop date + 3 days after permanent discontinuation of study drug; Any AEs with onset date on or after the study drug start date for those who have not permanently discontinued study drug; Any AEs leading to premature discontinuation of study drug. The most severe graded AE from all tests was counted for each participant.
• Percentage of Participants Who Experienced Graded Treatment-Emergent Laboratory Abnormalities at Week 48 [Week 48]: Graded treatment-emergent laboratory abnormalities were defined as values that increased at least 1 toxicity grade from baseline at any postbaseline visit, up to and including the date of last dose of study drug + 3 days for participants who permanently discontinued study drug or the last available date in the database snapshot for participants who were on treatment at the time of the analysis. The most severe graded abnormality from all tests was counted for each participant.
• Percentage of Participants Who Experienced Graded Treatment-Emergent Laboratory Abnormalities at Week 96 [Week 96]: Graded treatment-emergent laboratory abnormalities were defined as values that increased at least 1 toxicity grade from baseline at any post-baseline visit, up to and including the date of last dose of study drug + 3 days for participants who permanently discontinued study drug or the last available date in the database snapshot for participants who were on treatment at the time of the analysis. The most severe graded abnormality from all tests was counted for each participant.
• Change From Baseline in Estimated Glomerular Filtration Rate by the Cockcroft-Gault Formula (eGFRcg) in Participants With Moderate or Severe Renal Impairment and Hepatically Impaired Participants at Week 24 [Baseline, Week 24]: GFR is a measure of the rate at which blood is filtered by the kidney. Cockcroft-Gault is an equation (calculation) used to estimate GFR based on serum creatinine, weight, and gender. eGFRcg = (140 - age in years) x (body weight in kg) x (0.85 if female) divided by 72 x serum creatinine in mg/dL. Moderate renal impairment= 30 mL/min ≤ eGFRCG ≤ 59 mL/min Severe renal impairment= 15 mL/min ≤ eGFRCG < 30 mL/min Change from baseline was calculated as the value at Week 24 minus the value at Baseline.
• Change From Baseline in eGFRcg in Participants With Moderate or Severe Renal Impairment and Hepatically Impaired Participants at Week 48 [Baseline, Week 48]: GFR is a measure of the rate at which blood is filtered by the kidney. Cockcroft-Gault is an equation (calculation) used to estimate GFR based on serum creatinine, weight, and gender. eGFRcg = (140 - age in years) x (body weight in kg) x (0.85 if female) divided by 72 x serum creatinine in mg/dL. Moderate renal impairment= 30 mL/min ≤ eGFRCG ≤ 59 mL/min Severe renal impairment= 15 mL/min ≤ eGFRCG < 30 mL/min Change from baseline was calculated as the value at Week 48 minus the value at Baseline.
• Change From Baseline in eGFRcg in Participants With Moderate or Severe Renal Impairment and Hepatically Impaired Participants at Week 96 [Baseline, Week 96]: GFR is a measure of the rate at which blood is filtered by the kidney. Cockcroft-Gault is an equation (calculation) used to estimate GFR based on serum creatinine, weight, and gender. eGFRcg = (140 - age in years) x (body weight in kg) x (0.85 if female) divided by 72 x serum creatinine in mg/dL. Moderate renal impairment= 30 mL/min ≤ eGFRCG ≤ 59 mL/min Severe renal impairment= 15 mL/min ≤ eGFRCG < 30 mL/min Change from baseline was calculated as the value at Week 96 minus the value at Baseline.
• Percent Change From Baseline in Hip Bone Mineral Density (BMD) at Week 24 [Baseline, Week 24]: Percent change = Change from baseline at a postbaseline visit/baseline * 100%.
• Percent Change From Baseline in Hip BMD at Week 48 [Baseline, Week 48]: Percent change = Change from baseline at a postbaseline visit/baseline * 100%.
• Percent Change From Baseline in Hip BMD at Week 96 [Baseline, Week 96]: Percent change = Change from baseline at a postbaseline visit/baseline * 100%.
• Percent Change From Baseline in Spine BMD at Week 24 [Baseline, Week 24]: Percent change = Change from baseline at a postbaseline visit/baseline * 100%.
• Percent Change From Baseline in Spine BMD at Week 48 [Baseline, Week 48]: Percent change = Change from baseline at a postbaseline visit/baseline * 100%.
• Percent Change From Baseline in Spine BMD at Week 96 [Baseline, Week 96]: Percent change = Change from baseline at a postbaseline visit/baseline * 100%.
• Percentage of Participants Achieving Virologic Response (Plasma HBV DNA < 20 IU/mL) at Week 48 [Weeks 48]: The percentage of participants with HBV DNA < 20 IU/mL at Week 48 was determined by the Missing = Failure (M = F) approach.
• Percentage of Participants Achieving Virologic Response (Plasma HBV DNA < 20 IU/mL) at Week 96 [Weeks 96]: The percentage of participants with HBV DNA < 20 IU/mL at Week 48 was determined by the Missing = Failure (M = F) approach.
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Detected (≥ Lower Limit of Detection [LLOD]) at Week 24 [Week 24]: The percentage of participants with HBV DNA < 20 IU/mL and target detected (≥ LLOD; i.e. 10 IU/mL) at Week 24 was determined by the M = F approach.
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Detected (≥ LLOD) at Week 48 [Week 48]: The percentage of participants with HBV DNA < 20 IU/mL and target detected (≥ LLOD; i.e. 10 IU/mL) at Week 48 was determined by the M = F approach.
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Detected (≥ LLOD) at Week 96 [Week 96]: The percentage of participants with HBV DNA < 20 IU/mL and target detected (≥ LLOD; i.e. 10 IU/mL) at Week 96 was determined by the M = F approach.
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Not Detected (< LLOD) at Week 24 [Week 24]: The percentage of participants with HBV DNA < 20 IU/mL and target not detected (< LLOD; i.e. 10 IU/mL) at Week 24 was determined by the M = F approach.
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Not Detected (< LLOD) at Week 48 [Weeks 48]: The percentage of participants with HBV DNA < 20 IU/mL and target not detected (< LLOD; i.e. 10 IU/mL) at Week 48 was determined by the M = F approach.
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Not Detected (< LLOD) at Week 96 [Weeks 96]: The percentage of participants with HBV DNA < 20 IU/mL and target not detected (< LLOD; i.e. 10 IU/mL) at Week 96 was determined by the M = F approach.
• Percentage of Participants With Serological Response: Loss of Hepatitis B s-Antigen (HBsAg) at Week 24 [Week 24]: HBsAg loss was defined as HBsAg changing from positive at baseline to negative at a postbaseline. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Loss of HBsAg at Week 48 [Week 48]: HBsAg loss was defined as HBsAg changing from positive at baseline to negative at a postbaseline. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Loss of HBsAg at Week 96 [Week 96]: HBsAg loss was defined as HBsAg changing from positive at baseline to negative at a postbaseline. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Seroconversion to Anti-HBs at Week 24 [Week 24]: HBsAg seroconversion was defined as HBsAg loss and HBsAb test changing from negative/missing at baseline to positive at a postbaseline visit. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Seroconversion to Anti-HBs at Week 48 [Week 48]: HBsAg seroconversion was defined as HBsAg loss and HBsAb test changing from negative/missing at baseline to positive at a postbaseline visit. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Seroconversion to Anti-HBs at Week 96 [Week 96]: HBsAg seroconversion was defined as HBsAg loss and HBsAb test changing from negative/missing at baseline to positive at a postbaseline visit. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Loss of HBeAg in HBeAg-Positive Participants at Week 24 [Week 24]: HBeAg loss was defined as HBeAg changing from positive at baseline to negative at a postbaseline. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Loss of HBeAg in HBeAg-Positive Participants at Week 48 [Week 48]: HBeAg loss was defined as HBeAg changing from positive at baseline to negative at a postbaseline. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Loss of HBeAg in HBeAg-Positive Participants at Week 96 [Week 96]: HBeAg loss was defined as HBeAg changing from positive at baseline to negative at a postbaseline. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Seroconversion to Anti-HBe in HBeAg-Positive Participants at Week 24 [Week 24]: HBeAg seroconversion was defined as HBeAg loss and HBeAb test changing from negative/missing at baseline to positive at a postbaseline visit. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Seroconversion to Anti-HBe in HBeAg-Positive Participants at Week 48 [Week 48]: HBeAg seroconversion was defined as HBeAg loss and HBeAb test changing from negative/missing at baseline to positive at a postbaseline visit. The M = F approach was used for this analysis.
• Percentage of Participants With Serological Response: Seroconversion to Anti-HBe in HBeAg-Positive Participants at Week 96 [Week 96]: HBeAg seroconversion was defined as HBeAg loss and HBeAb test changing from negative/missing at baseline to positive at a postbaseline visit. The M = F approach was used for this analysis.
• Percentage of Participants With Normal Alanine Aminotransferase (ALT) at Week 24 by Central Laboratory and the American Association for the Study of Liver Diseases (AASLD) Criteria [Week 24]: Central laboratory ULN for ALT were as follows: ≤ 43 U/L for males aged 18 to < 69 years and ≤ 35 U/L for males aged ≥ 69 years; ≤ 34 U/L for females aged 18 to < 69 years and ≤ 32 U/L for females aged ≥ 69 years. The ULN for ALT using the 2018 AASLD normal range was 25 U/L for females and 35 U/L for males. The M = F approach was used for this analysis.
• Percentage of Participants With Normal ALT at Week 48 by Central Laboratory and the AASLD Criteria [Week 48]: Central laboratory ULN for ALT were as follows: ≤ 43 U/L for males aged 18 to < 69 years and ≤ 35 U/L for males aged ≥ 69 years; ≤ 34 U/L for females aged 18 to < 69 years and ≤ 32 U/L for females aged ≥ 69 years. The ULN for ALT using the 2018 AASLD normal range was 25 U/L for females and 35 U/L for males. The M = F approach was used for this analysis.
• Percentage of Participants With Normal ALT at Week 96 by Central Laboratory and the AASLD Criteria [Week 96]: Central laboratory ULN for ALT were as follows: ≤ 43 U/L for males aged 18 to < 69 years and ≤ 35 U/L for males aged ≥ 69 years; ≤ 34 U/L for females aged 18 to < 69 years and ≤ 32 U/L for females aged ≥ 69 years. The ULN for ALT using the 2018 AASLD normal range was 25 U/L for females and 35 U/L for males. The M = F approach was used for this analysis.
• Percentage of Participants With Normalized ALT at Week 24 by Central Laboratory and the AASLD Criteria [Week 24]: ALT normalization was defined as an ALT value that changed from above the normal range at baseline to within the normal range at the given postbaseline visit. Central laboratory ULN for ALT were as follows: ≤ 43 U/L for males aged 18 to < 69 years and ≤ 35 U/L for males aged ≥ 69 years; ≤ 34 U/L for females aged 18 to < 69 years and ≤ 32 U/L for females aged ≥ 69 years. The ULN for ALT using the 2018 AASLD normal range was 25 U/L for females and 35 U/L for males. The M = F approach was used for this analysis.
• Percentage of Participants With Normalized ALT at Week 48 by Central Laboratory and the AASLD Criteria [Week 48]: ALT normalization was defined as an ALT value that changed from above the normal range at baseline to within the normal range at the given postbaseline visit. Central laboratory ULN for ALT were as follows: ≤ 43 U/L for males aged 18 to < 69 years and ≤ 35 U/L for males aged ≥ 69 years; ≤ 34 U/L for females aged 18 to < 69 years and ≤ 32 U/L for females aged ≥ 69 years. The ULN for ALT using the 2018 AASLD normal range was 25 U/L for females and 35 U/L for males. The M = F approach was used for this analysis.
• Percentage of Participants With Normalized ALT at Week 96 by Central Laboratory and the AASLD Criteria [Week 96]: ALT normalization was defined as an ALT value that changed from above the normal range at baseline to within the normal range at the given postbaseline visit. Central laboratory ULN for ALT were as follows: ≤ 43 U/L for males aged 18 to < 69 years and ≤ 35 U/L for males aged ≥ 69 years; ≤ 34 U/L for females aged 18 to < 69 years and ≤ 32 U/L for females aged ≥ 69 years. The ULN for ALT using the 2018 AASLD normal range was 25 U/L for females and 35 U/L for males. The M = F approach was used for this analysis.
• Change From Baseline in FibroTest® Score at Week 24 [Baseline, Week 24]: The FibroTest® score is used to assess liver fibrosis. Scores range from 0.00 to 1.00, with higher scores indicating a greater degree of fibrosis. Change from baseline was calculated as the value at Week 24 minus the value at Baseline.
• Change From Baseline in FibroTest® Score at Week 48 [Baseline, Week 48]: The FibroTest® score is used to assess liver fibrosis. Scores range from 0.00 to 1.00, with higher scores indicating a greater degree of fibrosis. Change from baseline was calculated as the value at Week 48 minus the value at Baseline.
• Change From Baseline in FibroTest® Score at Week 96 [Week 96]: The FibroTest® score is used to assess liver fibrosis. Scores range from 0.00 to 1.00, with higher scores indicating a greater degree of fibrosis. Change from baseline was calculated as the value at Week 96 minus the value at Baseline.
• Change From Baseline in Child-Pugh-Turcotte (CPT) Score in Hepatically Impaired Participants at Week 24 [Baseline, Week 24]: CPT scores grade the severity of cirrhosis and are used to determine the need for liver transplantation. Scores can range from 5 to 15, with higher scores indicating a greater severity of disease.
• Change From Baseline in CPT Score in Hepatically Impaired Participants at Week 48 [Baseline, Week 48]: CPT scores grade the severity of cirrhosis and are used to determine the need for liver transplantation. Scores can range from 5 to 15, with higher scores indicating a greater severity of disease.
• Change From Baseline in CPT Score in Hepatically Impaired Participants at Week 96 [Baseline, Week 96]: CPT scores grade the severity of cirrhosis and are used to determine the need for liver transplantation. Scores can range from 5 to 15, with higher scores indicating a greater severity of disease.
• Change From Baseline in Model for End-Stage Liver Disease (MELD) Score in Hepatically Impaired Participants at Week 24 [Baseline, Week 24]: MELD scores are used to assess prognosis and suitability for liver transplantation. Scores can range from 6 to 40, with higher scores indicating greater disease severity.
• Change From Baseline in MELD Score in Hepatically Impaired Participants at Week 48 [Baseline, Week 48]: MELD scores are used to assess prognosis and suitability for liver transplantation. Scores can range from 6 to 40, with higher scores indicating greater disease severity.
• Change From Baseline in MELD Score in Hepatically Impaired Participants at Week 96 [Baseline, Week 96]: MELD scores are used to assess prognosis and suitability for liver transplantation. Scores can range from 6 to 40, with higher scores indicating greater disease severity.

Sex: All, ages: 18 Years to any

Key Inclusion Criteria:

All Participants (Parts A and B):

* Adult male or non-pregnant female individuals
* Documented evidence of chronic HBV infection
* Alanine aminotransferase (ALT) ≤ 10 × upper limit of normal (ULN)

Part A Only (renal impairment):

* Maintained on TDF and/or other OAV treatment(s) for CHB for at least 48 weeks and with viral suppression (HBV deoxyribonucleic acid \[DNA\] < lower limit of quantitation \[LLOQ\]) for ≥ 6 months prior to screening

  * All individuals must have HBV DNA < 20 International units per milliliter (IU/mL) at screening by central laboratory
  * Both Hepatitis B e-Antigen (HBeAg) positive and negative individuals are eligible to participate
* Moderate renal impairment (30 milliliters per minute \[mL/min\] ≤ estimated glomerular filtration rate by the cockcroft-gault formula \[eGFRcg\] ≤ 59 mL/min), severe renal impairment (15 mL/min ≤ eGFRcg < 30 mL/min) or end stage renal disease (ESRD) (eGFR < 15 mL/min) maintained on hemodialysis (HD)
* Stable renal function (for participants with moderate or severe impairment): serum creatinine measured at least once within three months prior to screening. The measurement difference between the value measured within three months prior to screening versus the screening value must be ≤ 25% of the screening value

Part B Only (hepatic impairment):

* Maintained on TDF and/or other OAV(s) for CHB for at least 48 weeks and with viral suppression (HBV DNA < LLOQ) for ≥ 6 months prior to screening

  * All individuals must have HBV DNA < 20 IU/mL at screening by central laboratory
  * Both HBeAg positive and negative individuals are eligible to participate
* Child-pugh-turcotte (CPT) score of 7-12 (inclusive) OR a past history of CPT score ≥ 7 and any CPT score ≤ 12 at screening
* eGFRCG ≥ 30 mL/min using the Cockcroft-Gault equation

Key Exclusion Criteria:

All Individuals (Parts A \& B):

* Women who are breastfeeding or who believe they may wish to become pregnant during the course of the study
* Males and females of reproductive potential who are unwilling to use an "effective", protocol-specified method(s) of contraception during the study
* Co-infection with hepatitis C virus (HCV), human immunodeficiency virus (HIV), or hepatitis D virus (HDV)
* Prior Interferon (IFN) use within 6 months of screening
* Evidence of hepatocellular carcinoma
* Received solid organ or bone marrow transplant
* Significant cardiovascular, pulmonary, or neurological disease
* Malignancy within 5 years prior to screening, with the exception of specific cancers that are cured by surgical resection (basal cell skin cancer, etc.). Individuals under evaluation for possible malignancy are not eligible
* Currently receiving therapy with immunomodulators (e.g. corticosteroids), nephrotoxic agents, or agents capable of modifying renal excretion
* Known hypersensitivity to study drugs, metabolites, or formulation excipients
* Current alcohol or substance abuse judged by the investigator to potentially interfere with individual's compliance
* Any other clinical condition or prior therapy that, in the opinion of the Investigator, would make the individual unsuitable for the study or unable to comply with dosing requirements.

Part A Only (Renal Impairment):

* Current or historical evidence of clinical hepatic decompensation (e.g., ascites, encephalopathy or variceal hemorrhage)
* Abnormal hematological and biochemical parameters, including:

  * Hemoglobin < 9 grams per deciliter (g/dL)
  * Absolute neutrophil count < 750/cubic millimeter (mm\^3)
  * Platelets ≤ 50,000/mm\^3
  * Aspartate aminotransferase (AST) > 10 × ULN
  * Albumin < 3.0 g/dL
  * Total bilirubin > 2.5 × ULN
  * International normalized ratio of prothrombin time (INR) > 1.5 × ULN (unless stable on anticoagulant regimen)
* Individuals with ESRD (i.e. eGFRcg < 15 mL/min) not on HD, or those on other forms of renal replacement therapy (i.e. peritoneal dialysis)

Part B Only (Hepatic Impairment):

* Active variceal bleeding within 6 months or prior placement of a portosystemic shunt (such as transjugular intrahepatic portosystemic shunt \[TIPS\])
* History of hepatorenal syndrome, hepatopulmonary syndrome, Grade 3 or Grade 4 hepatic encephalopathy, or spontaneous bacterial peritonitis within 6 months of screening
* Grade 2 hepatic encephalopathy at screening
* Model for end-stage liver disease (MELD) score ≥ 30
* Abnormal hematological and biochemical parameters, including

  * Absolute neutrophil count < 750/mm\^3
  * Platelets < 30,000/mm\^3
  * Hemoglobin < 8.0 g/dL

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Participant flow

Outcome results

• Percentage of Participants Achieving Virologic Response (Plasma Hepatitis B Virus [HBV] Deoxyribonucleic Acid [DNA] < 20 IU/mL) at Week 24 (Primary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 97.4; Part A (Renal Impairment): End Stage Renal Disease 100.0; Part B: Hepatic Impairment 100.0
• Percentage of Participants Who Experienced Graded Treatment-Emergent Adverse Events (AEs) at Week 24 (Primary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 53.8; Part A (Renal Impairment): End Stage Renal Disease 73.3; Part B: Hepatic Impairment 54.8
• Percentage of Participants Who Experienced Graded Treatment-Emergent Laboratory Abnormalities at Week 24 (Primary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 96.2; Part A (Renal Impairment): End Stage Renal Disease 100.0; Part B: Hepatic Impairment 90.3
• Percentage of Participants Who Experienced Graded Treatment-Emergent AEs at Week 48 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 71.8; Part A (Renal Impairment): End Stage Renal Disease 86.7; Part B: Hepatic Impairment 71.0
• Percentage of Participants Who Experienced Graded Treatment-Emergent AEs at Week 96 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 74.4; Part A (Renal Impairment): End Stage Renal Disease 100.0; Part B: Hepatic Impairment 77.4
• Percentage of Participants Who Experienced Graded Treatment-Emergent Laboratory Abnormalities at Week 48 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 96.2; Part A (Renal Impairment): End Stage Renal Disease 100.0; Part B: Hepatic Impairment 90.3
• Percentage of Participants Who Experienced Graded Treatment-Emergent Laboratory Abnormalities at Week 96 (Secondary), Number, percentage of particpants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 96.2; Part A (Renal Impairment): End Stage Renal Disease 100.0; Part B: Hepatic Impairment 100.0
• Change From Baseline in Estimated Glomerular Filtration Rate by the Cockcroft-Gault Formula (eGFRcg) in Participants With Moderate or Severe Renal Impairment and Hepatically Impaired Participants at Week 24 (Secondary), Median, mL/min: Part A (Renal Impairment): Moderate or Severe Renal Impairment -0.4 (-3.9 to 4.5); Part B: Hepatic Impairment 1.9 (-5.6 to 12.2)
• Change From Baseline in eGFRcg in Participants With Moderate or Severe Renal Impairment and Hepatically Impaired Participants at Week 48 (Secondary), Median, mL/min: Part A (Renal Impairment): Moderate or Severe Renal Impairment -0.5 (-4.1 to 3.0); Part B: Hepatic Impairment 1.2 (-13.5 to 6.5)
• Change From Baseline in eGFRcg in Participants With Moderate or Severe Renal Impairment and Hepatically Impaired Participants at Week 96 (Secondary), Median, mL/min: Part A (Renal Impairment): Moderate or Severe Renal Impairment 1.0 (-2.8 to 4.5); Part B: Hepatic Impairment -2.4 (-11.4 to 10.7)
• Percent Change From Baseline in Hip Bone Mineral Density (BMD) at Week 24 (Secondary), Mean, percent change: Part A (Renal Impairment): Moderate or Severe Renal Impairment 0.135 +/- 1.8348; Part A (Renal Impairment): End Stage Renal Disease 0.322 +/- 2.1835; Part B: Hepatic Impairment 0.322 +/- 2.5105
• Percent Change From Baseline in Hip BMD at Week 48 (Secondary), Mean, percent change: Part A (Renal Impairment): Moderate or Severe Renal Impairment 0.565 +/- 2.6160; Part A (Renal Impairment): End Stage Renal Disease -1.075 +/- 3.6355; Part B: Hepatic Impairment -0.221 +/- 3.0158
• Percent Change From Baseline in Hip BMD at Week 96 (Secondary), Mean, percent change: Part A (Renal Impairment): Moderate or Severe Renal Impairment 0.425 +/- 2.8381; Part A (Renal Impairment): End Stage Renal Disease -0.834 +/- 4.7171; Part B: Hepatic Impairment 0.277 +/- 3.2549
• Percent Change From Baseline in Spine BMD at Week 24 (Secondary), Mean, percent change: Part A (Renal Impairment): Moderate or Severe Renal Impairment 1.229 +/- 3.4252; Part A (Renal Impairment): End Stage Renal Disease 0.683 +/- 3.1370; Part B: Hepatic Impairment 1.258 +/- 2.3416
• Percent Change From Baseline in Spine BMD at Week 48 (Secondary), Mean, percent change: Part A (Renal Impairment): Moderate or Severe Renal Impairment 1.516 +/- 3.7486; Part A (Renal Impairment): End Stage Renal Disease 0.016 +/- 4.1636; Part B: Hepatic Impairment 0.535 +/- 3.4386
• Percent Change From Baseline in Spine BMD at Week 96 (Secondary), Mean, percent change: Part A (Renal Impairment): Moderate or Severe Renal Impairment 1.293 +/- 4.4136; Part A (Renal Impairment): End Stage Renal Disease -0.283 +/- 4.5327; Part B: Hepatic Impairment -0.249 +/- 3.9127
• Percentage of Participants Achieving Virologic Response (Plasma HBV DNA < 20 IU/mL) at Week 48 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 92.3; Part A (Renal Impairment): End Stage Renal Disease 93.3; Part B: Hepatic Impairment 100.0
• Percentage of Participants Achieving Virologic Response (Plasma HBV DNA < 20 IU/mL) at Week 96 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 83.3; Part A (Renal Impairment): End Stage Renal Disease 86.7; Part B: Hepatic Impairment 77.4
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Detected (≥ Lower Limit of Detection [LLOD]) at Week 24 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 21.8; Part A (Renal Impairment): End Stage Renal Disease 40.0; Part B: Hepatic Impairment 22.6
• Percentage of Participants With Plasma HBV DNA < 20 IU/mL and Target Detected (≥ LLOD) at Week 48 (Secondary), Number, percentage of participants: Part A (Renal Impairment): Moderate or Severe Renal Impairment 26.9; Part A (Renal Impairment): End Stage Renal Disease 26.7; Part B: Hepatic Impairment 25.8
• 31 more outcome measures not shown.

Adverse events

Time frame: Adverse Events: From the first dose date up to last dose date (maximum: 108.1 weeks) plus 3 days; All-Cause Mortality: Enrollment up to last dose date (maximum: 166.2 weeks) plus 3 days

Serious adverse events by term

Other adverse events by term

37 more terms not shown.

• Results publication: Lim YS, Lin CY, Heo J, Bae H, Chuang WL, Hui AJ, et al. Safety and Efficacy of Switching to Tenofovir Alafenamide in Virally Suppressed Chronic Hepatitis B Patients With Hepatic Impairment: Week-48 Results From a Phase 2 Open-label Study [Poster SAT442]. The Digital International Liver Congress (ILC); 2020 27-29 August.
• Results publication: Janssen HLA, Lampertico P, Chen CY, Heo J, Fournier C, Ahn SH, et al. Safety and Efficacy of Switching to Tenofovir Alafenamide in Virally Suppressed Chronic Hepatitis B Patients With Renal Impairment: Week-48 Results From a Phase 2 Open-label Study [Poster SAT429]. The Digital International Liver Congress (ILC); 2020 27-29 August.
• Results publication: Lim YS, Lampertico P, Bae H, Chuang WL, Heo J, Huang YH, et al. Switching From Tenofovir Disoproxil Fumarate or Other Oral Antiviral Therapy to Tenofovir Alafenamide in Virally Suppressed Chronic Hepatitis B Patients With Hepatic Impairment: Week 24 Efficacy and Safety Results From a Phase 2 Open-label Study [Poster 501]. AASLD: The Liver Meeting; 2019 08-12 November; Boston, MA.
• Results publication: Janssen HLA, Lim YS, Gane EJ, Fournier C, Ahn SH, Tsang O, et al. Efficacy and Safety of Switching to Tenofovir Alafenamide in Virally Suppressed Chronic Hepatitis B Patients With Renal Impairment: Week 24 Results From a Phase 2 Open-label Study [Poster 483]. AASLD: The Liver Meeting; 2019 08-12 November; Boston, MA.
• Results publication: Liu CJ, Lim YS, Chen CY, Chen CH, Huang YH, Lin CY, Lin CC, Yu ML, Abramov F, Yee LJ, Duan R, Flaherty JF, Su WW, Yang SS, Janssen HLA, Chuang WL. Switching to tenofovir alafenamide in virally-suppressed chronic hepatitis B patients with renal/hepatic impairment: Phase 2 study sub-analysis from Taiwan. J Formos Med Assoc. 2025 Jul 30:S0929-6646(25)00390-0. doi: 10.1016/j.jfma.2025.07.023. Online ahead of print. PMID 40744841
• Results publication: Janssen HLA, Lim YS, Lampertico P, Heo J, Chen CY, Fournier C, Tsang TYO, Bae H, Chen CH, Coffin CS, Ahn SH, Trinh H, Flaherty JF, Abramov F, Zhao Y, Liu Y, Lau A, German P, Chuang WL, Agarwal K, Gane E. Switching to tenofovir alafenamide in patients with virologically suppressed chronic hepatitis B and renal or hepatic impairment: final week 96 results from an open-label, multicentre, phase 2 study. Lancet Gastroenterol Hepatol. 2024 Aug;9(8):718-733. doi: 10.1016/S2468-1253(24)00096-7. Epub 2024 Jun 17. PMID 38901444

• Study Protocol (PDF, 2017-05-23)
• Statistical Analysis Plan (PDF, 2020-10-05)

• Gilead Study Director, Study director, Gilead Sciences

NIH grants: 2016