Failure of adefovir 20 mg to improve suboptimal response in lamivudine-resistant hepatitis B patients treated with adefovir 10 mg and lamivudine

Randomized trial of entecavir plus adefovir in patients with lamivudine-resistant chronic hepatitis B who show suboptimal response to lamivudine plus adefovir

A substantial proportion of patients with lamivudine-resistant hepatitis B virus (HBV) show suboptimal virologic response during rescue combination treatment with lamivudine plus adefovir. In this randomized active-control trial, 90 patients with serum HBV DNA levels of >2,000 IU/ml after at least 24 weeks of treatment with lamivudine-plus-adefovir therapy for lamivudine-resistant HBV were randomized to combination treatment with entecavir plus adefovir (ETV+ADV, n = 45) or continuation of lamivudine plus adefovir (LAM+ADV, n = 45) for 52 weeks. At baseline, patients' mean serum HBV DNA level was 4.60 log(10) IU/ml (standard deviation [SD], 1.03). All 90 patients completed 52 weeks of treatment. At week 52, the proportion of patients with serum HBV DNA levels of <60 IU/ml, the primary endpoint, was significantly higher in the ETV+ADV group than in the LAM+ADV group (n = 13, 29%, versus n = 2, 4%, respectively; P = 0.004). The mean reduction in serum HBV DNA levels from baseline was significantly greater in the ETV+ADV group than in the LAM+ADV group (-2.2 log(10) IU/ml versus -0.6 log(10) IU/ml, respectively; P < 0.001). At week 52, additional mutations causing resistance to adefovir or entecavir were analyzed in all patients with detectable HBV DNA by restriction fragment mass polymorphism assays and detected in none of the ETV+ADV group but in 15% of patients in the LAM+ADV group (P = 0.018). Safety and adverse event profiles were similar in the two groups. In conclusion, entecavir-plus-adefovir combination therapy provides superior virologic response and favorable resistance profiles, compared with the continuing lamivudine-plus-adefovir combination, in patients with lamivudine-resistant HBV who fail to respond to lamivudine-plus-adefovir combination therapy.

High dose lamivudine in HBV-related cirrhotic patients with unsatisfactory response after adefovir add-on

BACKGROUND

Before tenofovir approval for chronic hepatitis B therapy, the clinical management of patients with suboptimal response or virological breakthrough during combination treatment with lamivudine and adefovir dipivoxil was a difficult clinical challenge.

AIMS

In order to improve virologic response and reduce the risk of decompensation, we evaluate the efficacy of a high dose of lamivudine on chronic HBV patients who have previously presented an unsatisfactory response during treatment with lamivudine 100mg/day and adefovir 10mg/day.

METHODS

Six patients with HBV-related liver cirrhosis were prospectively enrolled. All were HBeAg-negative and presented a suboptimal response or virological breakthrough after "adefovir add-on" because of development of clinical breakthrough during Lamivudine treatment. Lamivudine dose was increased to 200 or 300 mg, depending on viral load. After 12 months of follow-up, virological and biochemical response were evaluated.

RESULTS

After 12 months of high-dose lamivudine, all patients (6/6, 100%) achieved a significant decrease of serum HBV DNA (mean reduction 2,62 ± 1,15 Log10 UI/ml, P = 0.03) and normalized ALT. In three patients (3/6, 50%), HBV DNA became undetectable within 6 months. No patient developed liver decompensation and no significant changes occurred in serum creatinine, serum and urinary electrolytes. No adverse events were registered.

CONCLUSIONS

In our experience, rescue strategy with high-dose lamivudine inhibited viral replication leading to undetectability of serum HBVDNA. This rescue treatment presented a good safety profile, without adverse events during the study period. Customized increase of nucleos(t)ide analogues dose in difficult-to-treat patients may be a proficient approach in challenging clinical setting.

Dynamics of hepatitis B virus resistance to adefovir in lamivudine-resistant patients

AIM: To investigate the dynamic changes of hepatitis B virus (HBV) mutants in lamivudine-resistant chronic hepatitis B (LAM-R CHB) patients who received sequential monotherapy with adefovir dipivoxil (ADV).

METHODS: Twenty-eight consecutive LAM-R CHB patients with viral breakthrough or inadequate virologic response during ADV monotherapy were studied. The dynamics of HBV mutants were analyzed over time by detecting the quantity of HBV DNA using real-time fluorescent quantitative PCR and by sequencing PCR products. Additionally, PCR-TA cloning was performed to study the dynamics of HBV quasispecies in 2 patients.

RESULTS: HBV DNA load fluctuated with the evolution of HBV mutants. Of all patients, 24 developed LAM resistance-associated substitutions during LAM therapy, and 4 had no resistance-associated mutations; 13 had LAM resistance-associated mutations, 11 had ADV resistance-associated mutations, and 7 had no resistance-associated mutations. Of 11 patients with ADV resistance-associated mutations, 6 had A181V mutation, 3 had A181T mutation, 1 had N236T mutation, and 1 had A181T/V+N236T mutation. PCR-TA cloning analysis showed that LAM-resistant viral population was gradually replaced by ADV-resistant viruses during ADV sequential monotherapy. We also detected rtI233M and rtA194T mutations that are associated with resistance to ADV and tenofovir, respectively.

CONCLUSION: Viral quasispecies dynamics in LAM-R CHB patients during ADV sequential monotherapy may manifest as various forms, such as LAM resistance-associated mutations with/without ADV resistance-associated mutations, or absence of resistance-associated mutations. Potential resistance quasispecies could be detected by PCR-TA cloning.