The efficacy of tenofovir-based therapy in patients showing suboptimal response to entecavir-adefovir combination therapy.
BACKGROUND/AIMS
Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination.


METHODS
We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy.


RESULTS
The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy.


CONCLUSIONS
The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.
['Kim|Jeong Han|JH|', 'Ahn|Sung Hyun|SH|', 'Ko|Soon Young|SY|', 'Choe|Won Hyeok|WH|', 'Kim|Kyun-Hwan|KH|', 'Kwon|So Young|SY|']
D000225:Adenine D000328:Adult D000368:Aged D000998:Antiviral Agents D004279:DNA, Viral D024882:Drug Resistance, Viral D004359:Drug Therapy, Combination D005260:Female D006147:Guanine D006515:Hepatitis B virus D019694:Hepatitis B, Chronic D006801:Humans D008297:Male D008875:Middle Aged D063065:Organophosphonates D016133:Polymerase Chain Reaction D056910:Republic of Korea D012189:Retrospective Studies D000068698:Tenofovir D016896:Treatment Outcome
Tenofovir Entecavir Adefovir Chronic Hepatitis B Resistance Lamivudine