HBV : No Detectable Tenofovir Resistance with Tenofovir Disoproxil Fumarate (TDF) or Emtricitabine+TDF (FTC/TDF) through 96 Weeks in Lamivudine Resistance CHB Patients

( Edward Gane ),( Amoreena C Corsa ),( Yang Liu ),( Ben C Mitchell2 ),( John F Flaherty ),( Michael D Miller ),( Kathryn M Kitrinos ),( Scott Fung ) 대한간학회 2013 춘·추계 학술대회 (KASL) Vol.2013 No.1

Background/Aim: To evaluate amino acid changes within HBV pol/RT after 96 weeks of treatment with TDF or FTC/ TDF and determine their potential association with TDF resistance. Methods: In Study GS-US-174-0121, 280 patients receiving lamivudine (LAM) with detectable LAM-resistance mutations in HBV pol/RT (LAM-R: rtM204V/I±rtL180M) were randomized 1:1 to receive blinded treatment with TDF or FTC/TDF for 96 weeks. Virologic breakthrough (VB) was defined as confirmed HBV DNA >1 log10 increase from nadir or HBV DNA ≥400 copies/mL (69 IU/mL) after <400 copies/mL. Resistance genotyping by HBV pol/RT sequencing was attempted for all patients at baseline and if viremic (HBV DNA ≥400 copies/ mL) at Week 96/study discontinuation. Results: Overall, 18 patients (9 TDF, 9 FTC/TDF) were viremic viremic at Week 96/last visit. The mean baseline HBV DNA was significantly higher for viremic patients (8.04 log10 copies/mL) compared to patients who did not qualify for genotyping (6.39 log10 copies/mL). In the TDF arm, 3 patients had conserved site changes/reversions (1 with VB), 1 had unique polymorphic site changes, 2 had no change, and 3 were unable to be genotyped. In the FTC/TDF arm, 2 patients had conserved site changes/reversions, 1 had unique polymorphic site changes, 4 had no change, and 2 were unable to be genotyped. No phenotypic resistance to TDF was observed. Four of eight (50%) patients had LAM-R reversions (rtV/I204M±rtM180L) on TDF while 1/8 (12.5%) patients on FTC/TDF had LAM-R reversions. Thirteen patients (4.6%) with prior entecavir (ETV) exposure and 25 patients (8.9%) with baseline ETV-R were enrolled; neither had an impact on viral kinetics. Conclusions: No TDF resistance has been detected through 96 weeks of treatment with either TDF or FTC/TDF in LAM-R patients. The presence of ETV-R or ETV exposure did not impact viral kinetics through 96 weeks. Resistance surveillance in this population will continue through Year 5.

Sofosbuvir/Velpatasvir/Voxilaprevir for 12 Weeks is a Safe and Effective Salvage Regimen in NS5A Inhibitor-Experienced Patients with Genotype1-6 Infection: The POLARIS-1 Study

( Edward J. Gane ),( Marc Bourliere ),( Stuart C. Gordon ),( Alnoor Ramji ),( Natarajan Ravendhran ),( Tram T. Tran ),( Rob H. Hyland ),( Jie Zhang ),( Hadas Dvory-sobol ),( Luisa M. Stamm ),( Diana M 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: NS5A inhibitors are potent DAAs which are key components of HCV treatment regimens. In combination with other DAAs, NS5A inhibitors provide cure to over 90% of patients. For patients who have failed a regimen with an NS5A inhibitor, there is concern about long-lasting NS5A RASs and currently no approved retreatment option. Sofosbuvir (SOF) and velpatasvir (VEL) are pangenotypic inhibitors of the NS5B and NS5A proteins, respectively, and voxilaprevir (VOX) is a pangenotypic NS3/4A protease inhibitor. This study evaluates treatment with a SOF/VEL/VOX for 12 weeks in patients who previously received an NS5A inhibitor. Methods: Eligible patients received at least 4 weeks of a prior NS5A inhibitor-containing. Those with HCV GT1 were randomized 1:1 to receive SOF/VEL/VOX (400mg/100 mg/100 mg) or matching placebo daily for 12 weeks, stratified by the presence or absence of cirrhosis. Patients of all other GTs were assigned to receive SOF/VEL/VOX for 12 weeks. Those patients assigned to receive placebo were offered deferred treatment with SOF/VEL/VOX for 12 weeks. The primary endpoint evaluated the superiority of SVR12 to a performance goal of 85%. Results: Of 415 patients enrolled and treated with SOF/VEL/VOX, 76% were male, 80% were white, 46% had compensated cirrhosis, and 57% had GT 1infection. The majority of patients had DAA experience with an NS5A inhibitor given in combination with an NS5B inhibitor, and the most common prior NS5A inhibitor was ledipasvir (50%). Treatment with SOF/VEL/VOX was well tolerated. No serious adverse events attributed to study medication were reported. Overall, 253/263 (96%) of patients treated with SOF/VEL/VOX achieved SVR12, which was superior to the prespecified goal of 85% (p<0.001). High SVR12 was achieved across HCV GTs and regardless of selected baseline factors such as cirrhosisand RASs at any position. Conclusions: SOF/VEL/VOX for 12 weeks is a safe, well-tolerated and effective treatment for patients previously failed an NS5A inhibitor-containing DAA regimen, a group that currently has no retreatment option.

Direct-Acting Antivirals in Renal Failure

( Edward Gane ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Patients with end-stage renal disease (ESRD) are at high risk for exposure to hepatitis C virus (HCV), with prevalence 5-10 times greater than in the general population because of increased transfusions and risks of nosocomial spread within dialysis units. In countries with endemic HCV infection, almost 50% of haemodialysis patients are infected although the incidence has fallen following the introduction of universal precautions, erythropoeitin and blood donor. Prior to DAA therapies, HCV-infected patients with severe renal impairment represented an area of unmet medical need because of poor tolerability to both interferon and ribavirin. Sofosbuvir-containing regimens (SOVALDI+RBV, HARVONI, EPCLUSA) have demonstrated high rates of sustained virologic response (SVR) in patients with chronic hepatitis C virus (HCV). However, these are not recommended in patients with severe renal impairment because of rapid accumulation of sofosbuvir and its major metabolite GS-331007. Despite this, many Real World studies are now reported excellent safety and efficacy with these regimens in patients with moderate and severe renal impairment. Other DAA regimens which do not contain a nucleotide NS5B inhibitor should be safe in this difficult-to-treat patient population. In RUBY1, 18/18 patients infected with HCV GT 1b and 46/50 patients with GT 1a treated with VIEKIRA PAK-RBV (OBV/PTV/r + DSV + RBV) achieved SVR including cirrhotics and treatment experienced. Only 1 GT1a patient had virologic failure. Most GT 1a patients reduced or stopped RBV because of anaemia without any impact on SVR. In the subsequent RUBY2 study, 13 patients with GT 1a were treated with VIEKIRA PAK without RBV (OBV/PTV/r + DSV) and all 13 achieved SVR. This suggests that RBV is not needed in non-cirrhotic patients with ESRD. In C-SURFER, 115/116 patients infected with HCV GT 1 treated with ZEPATIER (Elbasvir/grazoprevir) without RBV for 12 weeks achieved SVR. This suggests that baseline NS5A RASs do not influence efficacy in patients with ESRD. However, almost 50% of HCV+ patients with ESRD are infected with GT 2 or 3, which do not respond to either VIEKIRA PAK or ZEPATIER. The combination of the Glecaprevir (GLE, formerly ABT-493) and pibrentasvir (PIB, formerly ABT-530) may be the ideal regimen in patients with ESRD. Neither compound undergoes significant renal excretion and Phase 1 renal impairment studies demonstrated no clinically relevant increases in the exposure of GLE/PIB in patients with renal disease compared to those with normal renal function. In addition, this combination is pangenotypic. In EXPEDITION-4, 102/104 patients infected with HCV GT 1-6 treated with GLE/PIB for 12 weeks achieved SVR. There were no virologic failures and safety and tolerability was excellent with no ALT elevations. These results suggest that GLE/PIB is a suitable option for patients with advanced renal disease and support the pangenotypic efficacy of this regimen. Complete SVR12 data will be presented at the conference. In summary, new DAA regimens which are IFN and RBV-free, now provide safe and effective treatment for all patients with ESRD and HCV infection.

An Integrated Analysis of the Efficacy of Glecaparevir/ Pibrentasvir by Geographical Region

( Edward Gane ),( Kazuaki Chayama ),( Mudra Kapoor ),( Stuart K Roberts ),( Jeong Heo ),( Jia-horng Kao ),( Thomas Berg ),( Philippe J Zamor ),( Brian Conway ),( James Park ),( Sandra S Lovell ),( Rak 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: The pangenotypic direct-acting antiviral (DAA) regimen glecaprevir (developed by AbbVie and Enanta) coformulated with pibrentasvir (G/P) is approved in the US, EU, and Japan to treat chronic HCV genotype (GT) 1-6 infection. In the US and EU, G/P is indicated for treatment-naïve, HCV genotype (GT) 1-6-infected patients without and with compensated cirrhosis for 8-week and 12-week treatment durations, respectively, and achieved SVR12 rates ≥95% across all six major GTs. In clinical studies, G/P exposures were similar across ethnicities; an integrated analysis of the efficacy of G/P by geographical region was conducted to assess the impact of geography and ethnicity on SVR12. Methods: Data were pooled from 9 phase 2 and 3 clinical studies; data from 2 additional phase 3 clinical studies conducted in Japan were pooled separately. Patients had HCV GT1-6 infection with or without compensated cirrhosis and were either HCV treatment-naïve or experienced with interferon (IFN) or pegIFN with or without ribavirin (RBV), sofosbuvir and RBV with or without pegIFN, or NS5A- and/or protease inhibitor-containing regimens. G/P (300 mg/120 mg) was orally dosed once-daily for 8, 12, or 16 weeks. The primary efficacy endpoint in all studies was SVR12. Safety and tolerability were assessed in all patients. Data from all 11 studies will be pooled for presentation. Results: In total, 2369 patients were included in the integrated analysis: 964 (41%) were enrolled in North America, 891 (38%) in Europe, and 514 (22%) enrolled and pooled from Taiwan, Korea, Australia, New Zealand, Chile, Israel, and South Africa; 332 additional patients were enrolled in Japan. The SVR12 results by region were 97% (935/964; 95% CI 95.9-98.1), 98% (876/891; 95% CI 97.5-99.1), and 96% (496/514; 95% CI 94.9-98.1) for patients enrolled in North America, Europe, and the other pooled countries, respectively. Patients enrolled in Japan achieved a 98% (325/332; 95% CI 95.7-99.0) SVR12 rate. Less than 1% of all patients had virologic failure. G/P was well-tolerated with a favorable safety profile; treatment discontinuations due to adverse events and cases of drug-induced liver injury were rare (<1%). Conclusions: G/P efficacy, safety and tolerability were consistently favorable regardless of baseline characteristics, suggesting that recently updated HCV treatment guidelines for the use of G/P in clinical practice can be applied to all ethnicities and geographical regions, without need for modification.

The Safety and Tolerability of SOF/VEL/VOX for 8/12 Weeks in >1,000 Patients Treated in the POLARIS Studies: An Integrated Analysis

( Michael Manns ),( Edward J. Gane ),( Bernard E. Willems ),( Stuart K. Roberts ),( Steven Flamm ),( Marc Bourlière ),( Tarik Asselah ),( Laurent Alric ),( Sunjin Hwang ),( Robert H. Hyland ),( Luisa 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: The once-daily fixed-dose combination tablet of sofosbuvir/ velpatasvir/voxilaprevir (SOF/VEL/VOX) was evaluated for the treatment of genotype 1-6 HCV patients with and without compensated cirrhosis. Treatment was for 12 weeks for DAA-experienced patients (POLARIS-1 and POLARIS-4) and for 8 weeks for DAA-naive patients (POLARIS-2 and POLARIS-3). This analysis describes the safety of these 4 Phase 3 studies. Methods: Treatment-emergent adverse events (AEs) and laboratory abnormalities were assessed in patients who received SOF/VEL/VOX or placebo for 12 weeks(POLARIS-1), SOF/VEL/VOX or SOF/VEL for 12 weeks(POLARIS-4), or SOF/VEL/VOX for 8 weeks or SOF/VEL for 12 weeks(POLARIS-2 and POLARIS-3). SAEs and deaths were followed until post-treatment Week 24. Results: 1056 patients were treated with SOF/VEL/VOX for 8 (n=611) or 12 (n=445) weeks, 700 received SOF/VEL for 12 weeks, and 152 received placebo. 38% had compensated cirrhosis, 28% had a BMI ≥30 kg/m2, 36% were female, and 12% were ≥65 years old. Two deaths were reported, one illicit drug overdose and one attributed to hypertension, neither were related to treatment. SAEs and discontinuations were more frequent in the placebo group and occurred with similar frequency in the other groups; none were related to study treatment. Headache, fatigue, nausea, and diarrhea were the most common AEs. Mild diarrhea and nausea occurred more frequently in the SOF/VEL/VOX groups. Overall, 5.1 - 6.6% of patients who received SOF/VEL/VOX or SOF/VEL had Grade 3 or 4 laboratory abnormalities. Among patients receiving VOX, one patient each had a Grade 3 elevation in ALT and bilirubin. Conclusions: SOF/VEL/VOX for 8 or 12 weeks in the POLARIS studies was well tolerated with a low frequency of Grade 3 or 4 AEs, SAEs, and AEs leading to discontinuation. The frequency of AEs in the SOF/VEL/VOX groups was similar to SOF/VEL and placebo groups, with higher rates of mild diarrhea and nausea compared to SOF/VEL.

Efficacy, safety, and pharmacokinetics of capsid assembly modulator linvencorvir plus standard of care in chronic hepatitis B patients

Jinlin Hou,Edward Gane,Rozalina Balabanska,Wenhong Zhang,Jiming Zhang,Tien Huey Lim,Qing Xie,Chau-Ting Yeh,Sheng-Shun Yang,Xieer Liang,Piyawat Komolmit,Apinya Leerapun,Zenghui Xue,Ethan Chen,Yuchen Zh 대한간학회 2024 Clinical and Molecular Hepatology(대한간학회지) Vol.30 No.2

Background/Aims: Four-week treatment of linvencorvir (RO7049389) was generally safe and well tolerated, and showed anti-viral activity in chronic hepatitis B (CHB) patients. This study evaluated the efficacy, safety, and pharmacokinetics of 48-week treatment with linvencorvir plus standard of care (SoC) in CHB patients. Methods: This was a multicentre, non-randomized, non-controlled, open-label phase 2 study enrolling three cohorts: nucleos(t)ide analogue (NUC)-suppressed patients received linvencorvir plus NUC (Cohort A, n=32); treatment-naïve patients received linvencorvir plus NUC without (Cohort B, n=10) or with (Cohort C, n=30) pegylated interferon-α (Peg-IFN-α). Treatment duration was 48 weeks, followed by NUC alone for 24 weeks. Results: 68 patients completed the study. No patient achieved functional cure (sustained HBsAg loss and unquantifiable HBV DNA). By Week 48, 89% of treatment-naïve patients (10/10 Cohort B; 24/28 Cohort C) reached unquantifiable HBV DNA. Unquantifiable HBV RNA was achieved in 92% of patients with quantifiable baseline HBV RNA (14/15 Cohort A, 8/8 Cohort B, 22/25 Cohort C) at Week 48 along with partially sustained HBV RNA responses in treatment-naïve patients during follow-up period. Pronounced reductions in HBeAg and HBcrAg were observed in treatment-naïve patients, while HBsAg decline was only observed in Cohort C. Most adverse events were grade 1–2, and no linvencorvir-related serious adverse events were reported. Conclusions: 48-week linvencorvir plus SoC was generally safe and well tolerated, and resulted in potent HBV DNA and RNA suppression. However, 48-week linvencorvir plus NUC with or without Peg-IFN did not result in the achievement of functional cure in any patient.

Safety and Efficacy at 1-Year after Switching from TDF to TAF in CHB Patients with Risk Factors for TDF Use

( Byoung Kuk Jang ),( Edward Gane ),( Wai Kay Seto ),( Harry La Janssen ),( Florin A Caruntu ),( Hyung Joon Kim ),( Dzhamal Abdurakhmanov ),( Shuhei Nishiguchi ),( Andrzej Horban ),( Ho Bae ),( John F 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Tenofovir alafenamide (TAF), a new prodrug of tenofovir (TFV), is now a preferred treatment in the 2017 EASL HBV Guidelines, and may be particularly useful in patients with risk factors for TDF associated renal and bone effects. We assessed the 1 year safety and efficacy in CHB patients with TDF risk factors who were switched from TDF to TAF. Methods: In two identically-designed Phase 3 studies, HBeAg(+) and HBeAg(-)patients were randomized 2:1 to TAF 25 mg or TDF 300 mg and treated in a double- blind fashion for 96 weeks; all patients received open-label (OL) TAF for an additional 48 weeks (through Week 144). Renal and bone safety parameters, and antiviral efficacy (HBV DNA < 29 IU/mL) and ALT normalization were assessed in the subset of switch patients with baseline risk factors for TDF use: Age >60 years, osteoporosis of hip or spine, ³Stage 2 CKD (GFRCG < 90 mL/ min), albuminurina (UACR >30 mg/g), hypophosphatemia (PO4 <2.5 mg/dL), or presence of comorbidities (e.g. HTN, DM). Results: Of 1298 patients randomized and treated in the 2 studies, 540(42%) switched to open- label TAF at Week 96 (TAF^®TAF 360; TDF^®TAF 180), of which 284(53%) patients had at least 1 TDF risk factor at baseline; 123(23%) patients had ³2 risk factors. Baseline demographics and disease characteristics were similar between treatment groups. At Week 144, significant improvements in renal (sCr, eGFRCG) parameters, hip and spine BMD were observed and summarized in the table. Antiviral efficacy was maintained at Week 144 in both groups and in TDF patients who switched to TAF, increased rates of ALT normalization were seen. Conclusions: In CHB patients with risk factors for potential TDF toxicity, switching from TDF to TAF resulted in improved bone and renal safety parameters while efficacy was maintained in this subgroup at one year.

Long-Term Course of Cirrhosis Regression: Lessons from Patients with HCV Cirrhosis Following Successful Sofosbuvir-Based Treatment

( Ira Jacobson ),( Andrew J. Muir ),( Eric Lawitz ),( Edward Gane ),( Brian Conway ),( Peter J. Ruane ),( Ziad Younes ),( Frances Chen ),( Marianne Camargo ),( Anand P. Chokkalingam ),( C. Stephen Dje 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: In patients with HCV cirrhosis, a sustained virologic response (SVR) is associated with improved clinical outcomes; however, the temporal course of changes in fibrosis is poorly understood. Our aim was to evaluate changes in noninvasive tests of fibrosis (NITs) in this setting to gain insights into the natural history of cirrhosis regression following removal of the causative exposure. Methods: We studied patients with HCV cirrhosis who achieved SVR with sofosbuvir (SOF)-based regimens (in a trial or clinical practice) in an ongoing, prospective cirrhosis registry (NCT02292706). Patients underwent routine clinical and laboratory assessments, including semi-annual Child-Pugh-Turcotte (CPT) scoring and measurement of the Enhanced Liver Fibrosis (ELF) test, as well as annual liver stiffness measurement by transient elastography (LS by TE). Changes in fibrosis were estimated based on ELF response (defined as ≥0.5 unit reduction), and shifts in estimated fibrosis categories based on ELF (F3, ELF 9.8-11.3; F4, ELF >11.3) and LS by TE (F3, 9.6-12.5 kPa; F4, >12.5 kPa). Logistic regression was used to identify predictors of fibrosis improvement as defined by NITs. Results: 1,574 subjects with HCV cirrhosis (32% female, 39% BMI ≥30 kg/㎡, 7% CPT class B/C) were included in this study; median interval between SVR and registry enrollment was 38 weeks (IQR 27-60). At enrollment, median (IQR) ELF was 14.3 (9.5, 22.1); 586 (37%) and 247 (16%) patients had ELF scores consistent with F3 and F4 fibrosis, respectively. Median LS by TE was 9.9 kPa (9.2, 10.8); 761 (57%) and 227 (17%) patients had LS consistent with F3 and F4 fibrosis, respectively. As of May 2019, median duration of follow-up after registry enrollment was 123 weeks (IQR 96, 168). At week 144, 49% of those with baseline CPT class B/C had improved CPT class, while 98% of those with baseline CPT class A remained in CPT class A. During follow-up, changes in ELF and LS by TE suggested fibrosis improvement in an increasing proportion of patients with both F3 and F4 fibrosis at enrollment (Figure 1). ELF score improved by >0.5 units at week 144 in 27% and 47% of patients with baseline F3 and F4 fibrosis, respectively. Predictors of ELF improvement included higher ELF (P<0.001) and AST (P=0.049), and lower platelets (P=0.02) and BMI (P=0.10) at registry baseline. Conclusions: In patients with cirrhosis in whom HCV has been eradicated by SOF-based therapy, NITs suggest significant fibrosis improvement in 25-50% of patients within 3 years. Associations between reductions in these NITs and improvements in clinical outcomes require evaluation during longer-term follow-up.

Twelve Weeks of Ledipasvir/Sofosbuvir for Patients with Chronic Hepatitis C Genotype 2 Infection: Integrated Analysis of Three Clinical Studies

( Chung-feng Huang ),( Yasuhiro Asahina ),( Chun-jen Liu ),( Edward Gane ),( Yoshito Itoh ),( Norifumi Kawada ),( Yoshiyuki Ueno ),( Jin Youn ),( Chen-yu Wang ),( Joe Llewellyn ),( Anu Osinusi ),( Jen 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: HCV genotype (GT) 2 is the second most common genotype in several Asian countries including Taiwan and Korea. Treatment options for GT2 remain limited in these countries. The once-daily fixed-dose combination of ledipasvir/sofosbuvir (LDV/SOF) was evaluated for the treatment of GT 2, in patients with or without compensated cirrhosis, in three phase 2 and 3 studies. Methods: This was a retrospective analysis of subjects treated with LDV/SOF for 12 weeks in the GS-US-337-1655 (Taiwan), GS-US-337-1903 (Japan) and GS-US-1468 (New Zealand) studies. Subjects analyzed in this integrated analysis were either mono-infected with HCV GT2, or co-infected with HCV GT2 and HBV. The data was pooled and safety and efficacy were analyzed. Results: Overall 200 subjects were treated and analyzed; 88% of subjects were Asian, 46% male, 31% had prior treatment failure, 15% were cirrhotic, 25% were IL28B non-CC, 34% were 65 years or older and 22% (n=43) were co-infected with HBV. The overall SVR rate was 97% (194/200), and was 93% (27/29) among patients with cirrhosis and 97% (59/61) in patients who had failed previous therapy. Of the 197 patients with available testing; NS5A resistance-associated substitutions (RASs) were present in 86% (169/197) at baseline. SVR12 rate was 98% (165/169) in patients with baseline NS5A RASs compared with 100% (28/28) in patients without NS5A RASs. No new RASs emerged in patients with virologic failure. Treatment with LDV/SOF for 12 weeks was well tolerated. Overall the most common adverse events AEs were headache and nasopharyngitis. Few subjects experienced serious AEs, none of which were assessed as treatment related. One patient discontinued treatment due to AE. Conclusions: Treatment with LDV/SOF for 12 weeks is highly effective and well tolerated in patients with GT2 HCV infection, including patients who are treatment experienced and/or have compensated cirrhosis, baseline NS5A RASs and with HBV/HCV coinfection.

Switching from Tenofovir Disoproxil Fumarate (TDF) to Tenofovir Alafenamide (TAF) in Virally Suppressed Chronic Hepatitis B (CHB) Patients with Moderate or Severe Renal Impairment, or in End-Stage Renal Disease (ESRD) Patients on Hemodialysis (HD): Week 2

( Jeong Heo ),( Harry L.A. Janssen ),( Young-suk Lim ),( Edward J. Gane ),( Claire Fournier ),( Sang Hoon Ahn ),( Owen Tsang ),( Wan-long Chuang ),( Aric Josun Hui ),( Magdy Elkhashab ),( Chi-yi Chen 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: TAF, a novel tenofovir prodrug, has demonstrated noninferior efficacy to TDF with superior bone and renal safety in virally suppressed CHB patients with eGFR (by Cockcroft-Gault; eGFR_CG) ³50 mL/min when switched from TDF. The efficacy and safety of virally suppressed patients on TDF with renal impairment who were switched to TAF were evaluated in this Phase 2 study. Methods: CHB patients with renal impairment taking TDF for ³48 weeks and virally suppressed for ³6 months with HBV DNA <20 IU/mL at screening were enrolled into 2 cohorts: 1) moderate-severe renal impairment (eGFR_CG 15 to <60mL/min) and 2) ESRD (eGFR_CG <15 mL/min) patients on chronic HD. All patients were switched to TAF 25 mg QD for 96 weeks. Co-primary endpoints were proportion with HBV DNA <20 IU/mL and graded adverse events (AEs)/lab abnormalities at Week 24. Results: 93 patients (Mod-severe impairment 78; ESRD 15) were enrolled from 26 sites in 8 countries. Median age was 65 years, 74% male, 77% Asian, 83% HBeAg-negative, up to 60% had low BMD at hip and/or spine, and 60% and 24% had a history of HTN and/or diabetes, respectively. Key efficacy/safety results at Week 24 are summarized in the Table. All patients on treatment at Week 24 maintained HBV DNA <20 IU/mL and a high proportion had normal ALT levels. Relative to baseline levels, switching to TAF from TDF resulted in increases in hip/spine BMD, decreases in bone turnover markers, as well as increases in eGFR_CG and decreases in renal tubular markers. TAF was well tolerated with few having Grade 3 or 4 AEs (8%) and no discontinuations due to AEs. Conclusions: In renally-impaired CHB patients, including ESRD patients on HD, viral suppression was well maintained and the bone and renal safety were improved 24 weeks after switching from TDF to TAF.