S-4 Incidence, predictors and clinical course of PVR to tenofovir in NUC-naive patients with CHB = S-4 Incidence, predictors and clinical course of PVR to tenofovir in NUC-naive patients with CHB

다국어 초록 (Multilingual Abstract)

Background: Partial virological response (PVR) to nucleos(t)ide analogues (NUC) are defined by patients with detectable HBV DNA (＞10-15 IU/ml) at week 24 or week 48. Clinical importance of NUC PVR relates to developing resistance to long-term HBV treatment and requires rescue therapy from potent drugs such as entecavir(ETV) or tenofovir (TDF). Third generation NUCs (ETV, TDF) carry lower risk of resistance to long-term monotherapy, and the association between PVR and secondary treatment failure is not well established. There are studies regarding the efficacy of long?term ETV therapy. However, clinical significance of long term TDF is not known. We aim to assess the prevalence of PVR to TDF, the predictive factors associated with PVR, and clinical course in treatment-naive patients with chronic hepatitis B. Methods: We retrospectively analyzed 566 treatment naive patients with CHB who received TDF monotherapy over 6months at Severance Hospital. PVR at week 24 and week 48 were compared against patients with Complete virologic response (CVR) at 6months. Multivariate analysis was done to evaluate predictive factors of PVR. Cumulative probability of CVR was compared in patients with PVR. Results: Among 566 patients with TDF, 452 (79.9%) patients achieved CVR upon 48 weeks of TDF therapy and 510 (90.1%) achieved CVR after 96 weeks of TDF therapy. 241 (42.5%) of NUC-naive patients treated with TDF achieved PVR at week 24, and 114 (20.1%) patients achieved PVR at week 48. Using multivariate analysis, HBeAg positivity (Odds Ratio [OR] 2.501, 95% CI 1.56-4.010, p＜0.0001) and baseline HBV DNA level (OR 1.633, 95% CI 1.386-1.909, p＜0.0001) were predictive factors for PVR at week 24. Only baseline HBV DNA level (OR 1.813, 95% CI 1.432-2.295) was predictive factor for PVR at week 48. Cumulative CVR was significantly different (p＝0.005) among patients with PVR at week 24 with HBV DNA levels ＜7 log10 IU/mL and patients with HBV DNA level≥7 log10IU/mL. Conclusions: Elevated baseline HBV-DNA level was both associated with PVR at week 24 and PVR at week 48. HBeAg positivity was associated with PVR at week 24. Prolonged TDF therapy in NUC-naive patients with PVR leads to CVR of majority of patients.