Prediction of virologic response to tenofovir mono-rescue therapy for multidrug resistant chronic hepatitis B

Treatment Outcome and Renal Safety of 3-Year Tenofovir Disoproxil Fumarate Therapy in Chronic Hepatitis B Patients with Preserved Glomerular Filtration Rate

Background/Aims

To investigate the treatment efficacy and renal safety of long-term tenofovir disoproxil fumarate (TDF) therapy in chronic hepatitis B (CHB) patients with preserved renal function.

Methods

The medical records of 919 CHB patients who were treated with TDF therapy were reviewed. All patients had preserved renal function with an estimated glomerular filtration rate (eGFR) of at least 60 mL/min/1.73 m².

Results

A total of 426 patients (184 treatment-naïve and 242 treatment-experienced) were included for analysis. A virologic response (VR) was defined as achieving an undetectable serum hepatitis B virus (HBV) DNA level, and the overall VR was 74.9%, 86.7%, and 89.4% at the 1, 2, and 3-year follow-ups, respectively. Achieving a VR was not influenced by previous treatment experience, TDF combination therapy, or antiviral resistance. In a multivariate analysis, being hepatitis B e antigen positive at baseline and having a serum HBV DNA level ≥2,000 IU/mL at 12 months were associated with lower VR rates during the long-term TDF therapy. The overall renal impairment was 2.9%, 1.8%, and 1.7% at the 1, 2, and 3-year follow-ups, respectively. With regard to renal safety, underlying diabetes mellitus (DM) and an initial eGFR of 60 to 89 mL/min/1.73 m² were significant independent predictors of renal impairment.

Conclusions

TDF therapy appears to be an effective treatment option for CHB patients with a preserved GFR. However, patients with underlying DM and initial mild renal dysfunction (eGFR, 60 to 89 mL/min/1.73 m²) have an increased risk of renal impairment.

Efficacy of tenofovir disoproxil fumarate switch therapy in chronic hepatitis B patients with suboptimal response to adefovir-based combination therapy

In the present study, the efficacy and safety of tenofovir disoproxil fumarate (TDF) switch therapy were assessed in patients with chronic hepatitis B exhibiting a suboptimal response to adefovir (ADV)-based combination therapy. First, the efficacy of the TDF switch therapy was retrospectively evaluated in 50 patients with chronic hepatitis B who failed to respond to ADV-based combination treatment. Among those, 48 patients with a median age of 35 years were hepatitis B e antigen (HBeAg)-positive and 17, 14 and 19 patients were previously treated with lamivudine (LAM) plus ADV, telbivudine plus ADV and entecavir (ETV) plus ADV, respectively. A total of 41 patients were treated with TDF alone and 9 with TDF plus ETV. The median time of follow-up was 102 weeks. The primary end-point was the cumulative probability of achieving a complete virologic response (CVR). The secondary end-points were the rate of alanine aminotransferase (ALT) normalization, HBeAg seroconversion in HBeAg-positive patients, and the plasma levels of creatinine and creatine kinase. The mean serum hepatitis B virus DNA levels prior to initiation of the TDF switch therapy were 4.8±1.6 log₁₀IU/ml. The cumulative probability of achieving a VR at 24, 48, 96 and 108 weeks was 52.0, 76.0, 89.8 and 94.9%, respectively. The cumulative probability of normalization of ALT at 12, 24, 36, 48, 60,72, 84, 96, 108, 120 and 132 weeks was 34, 44, 50, 58, 66, 70, 74, 80, 90, 92 and 94%, respectively. HBeAg seroconversion was achieved in 5 patients. During the follow-up, 6 patients suffered from a virologic breakthrough, 3 patients failed to respond to the TDF treatment and the remaining patients were able to obtain VR following the continuation of TDF treatment. Slightly elevated serum levels of creatinine were observed in one patient, whereas creatine kinase activity did not increase in any of the subjects. In conclusion, TDF switch therapy is efficient and safe for patients with chronic hepatitis B with a suboptimal response to ADV-based combination therapy.

Step-down strategy in antiviral resistant chronic hepatitis B patients who achieved viral suppression with rescue combination therapy

In the treatment of chronic hepatitis B (CHB) patients with drug resistance, rescue combination therapy leads to viral suppression in almost all patients. However, once it is achieved, lifelong maintenance especially, by using combination therapy is not always possible in a significant proportion of patients. At present, there is no consensus on whether it is possible to switch to monotherapy from combination therapy. However, there is robust evidence to support step-down therapy, which involves switching from combination therapy to monotherapy in antiviral resistant CHB patients who achieve complete viral response from combination therapy. We review the evidence in favor of switching to monotherapy in antiviral resistant CHB patients who achieve complete viral response by combination therapy.

Real World Experience of Telbivudine Versus Entecavir in Patients with Chronic Hepatitis B, Including Long-Term Outcomes after Treatment Modification

PURPOSE

To estimate long-term outcomes after treatment modification in patients with chronic hepatitis B (CHB) treated with entecavir (ETV) and telbivudine (LdT).

MATERIALS AND METHODS

The study enrolled 131 nucleos(t)ide analogue (NA)-naïve CHB patients treated with ETV or LdT. During the 3-year study, NA treatment history including the incidence, the type of treatment modification, reasons for the modification, and overall complete virologic response (CVR) rate were retrospectively evaluated using the patients' medical records.

RESULTS

Among the 131 patients, 84 and 47 were initially treated with ETV and LdT, respectively. During the course of 3-year study, 82 patients in the ETV group (97.6%) maintained initial treatment whereas only 19 in the LdT group (40.4%). In the LdT group, 26 patients (92.9%) switched to another NA and another NA was added in 2 (7.1%) patients. An assessment of the CVR rate at 3 years, including treatment modification, showed that 89.3% and 95.7% of patients in the ETV and LdT groups, respectively, had undetectable serum hepatitis B virus DNA levels (p=0.329). Among LdT patients with treatment modification, the cumulative incidence rate of a CVR for rescue therapy was significantly higher in the tenofovir than in the ETV group (p=0.009).

CONCLUSION

During the 3-year study, there were no significant differences in the CVR between the ETV and LdT groups if appropriate rescue therapy was considered.

Treatment Efficacy and Safety of Tenofovir-Based Therapy in Chronic Hepatitis B: A Real Life Cohort Study in Korea

Background & Aims

We evaluated the efficacy and safety of Tenofovir disoproxil fumarate (TDF)-based therapy in naïve and treatment-experienced chronic hepatitis B (CHB) patients for 96 weeks in Korean real life practice.

Methods

A total of 209 CHB patients with a prescription for TDF at the Seoul and Daejeon St. Mary’s hospitals were enrolled from December 2012 to October 2014. We compared the virological responses and evaluated the renal safety of treatment-naive and treatment-experienced patients.

Results

An overall complete virological response (CVR) was achieved in 80.4% and 84.6% of patients at weeks 48 and 96, respectively. In a subgroup analysis, CVR at week 96 was present in 88.4%, 75.0%, 75.5%, and 83.3% of participants in the lamivudine-resistant (LAM-R) group, adefovir-resistant (ADV-R) group, multidrug-resistant (MDR) group, and suboptimal response group, respectively. In a multivariate analysis, ADV-R, MDR, hepatitis B virus DNA, and hepatitis B e antigen were independent predictors for CVR. With regard to renal safety, diabetes mellitus, cirrhosis, and an initial low estimated glomerular filtration rate were independent factors affecting creatinine elevation (≥0.5 mg/dL). Moreover, two patients with DM and cirrhosis experienced TDF-related Fanconi syndrome.

Conclusions

TDF-based therapy demonstrated sustained viral suppression and favorable safety during a 2-year treatment period. The LAM-R and suboptimal response groups showed comparable efficacy to the naïve group, while the ADV-R and MDR groups were significantly associated with a low CVR. Close monitoring of renal safety should be mandatory when treating CHB patients receiving TDF, particularly those with DM and cirrhosis.

Treatment of chronic hepatitis B with tenofovir

Tenofovir (TDF) is a potent hepatitis B virus (HBV) inhibitor with a high barrier to drug resistance, and it has been recommended as one of the first-line drugs to treat chronic hepatitis B (CHB). This paper reviews the recent advances in the treatment of CHB with TDF, especially in terms of its efficacy as first-line and second-line antiviral therapies as well as its role in the prevention of mother-to-child HBV transmission.