According to international guidelines, 6-12 months of consolidation therapy before stopping NA is associated with increased sustained response. There is however limited evidence whether this is the ideal duration of consolidation therapy. METHODS: We analyzed 94 patients who stopped NA after at least one year of therapy. Patients could be HBeAg-positive or HBeAg-negative at start-of-therapy, but all were HBeAg-negative
and had undetectable HBV DNA (<200 IU/mL) at time of discontinuation. Consolidation therapy was defined as treatment duration between the first undetectable HBV DNA (in case of HBeAg-positive patients after HBeAg loss) and NA discontinuation. Relapse was defined as HBV DNA >2,000 IU/mL measured twice 6 months apart within one year, EPZ015666 clinical trial or retreatment BGJ398 cell line after an initial HBV
DNA elevation. RESULTS: Median follow-up was 19.4 months with a median consolidation therapy duration of 2.5 years. At start-of-therapy, 35 patients were HBeAg-positive and 59 were HBeAg-negative. The cumulative relapse rate was 33 %at 6 months, 42.7 %at 1 year, and 64.4 %at 5 years. Start-of-therapy HBeAg-status did not have significant effect on post-treatment relapse even after extensive multivariable analysis. Prolonged consolidation therapy was independently associated with a reduced risk of relapse (Hazard ratio 0.48; 95 %CI 0.24-0.96 for 3 vs. 1 year). Patients with at least 3 years of consolidation therapy (n=37) had a one-year relapse rate of 23.2 %compared to 57.2 %for 1-3 years of consolidation therapy (n=32), and 55.5 %for <1 year of consolidation therapy (n=20)(P=0.002). After NA stop, nine patients lost HBsAg resulting in a five-year cumulative HBsAg loss rate of 15.1%. For each additional year of consolidation therapy, patients were 1.3-fold more likely to lose HBsAg (Hazard ratio 1.34; 95 %CI 1.02-1.75). Two cirrhotic patients developed hepatic decompensation,
but there were no deaths. CONCLUSIONS: Regardless of start-of-therapy HBeAg-status, 64 %of CHB patients experienced a relapse within 5 years after stopping NA. Consolidation therapy of at least 3 years decreased the rate of relapse and increased the rate of HBsAg loss significantly. Vorinostat concentration This study suggests that prolongation of the currently recommended 6-12 months consolidation therapy is needed. Disclosures: Colina Yim – Advisory Committees or Review Panels: Merck Canada, Gilead, Janssen Jordan J. Feld – Advisory Committees or Review Panels: Idenix, Merck, Janssen, Gilead, AbbVie, Merck, Theravance, Bristol Meiers Squibb; Grant/Research Support: AbbVie, Boehringer Ingelheim, Janssen, Gilead, Merck Robert J. de Knegt – Advisory Committees or Review Panels: MSD, Roche, Norgine, Janssen Cilag; Grant/Research Support: Gilead, MSD, Roche, Janssen Cilag, BMS; Speaking and Teaching: Gilead, MSD, Roche, Janssen Cilag David K.