Conference Reports for NATAP

Presented at the 22nd Conference of the Asian Pacific Association for the Study of the Liver (APASL) Taipei, Taiwan February 16-19, 2012 Back

Low Baseline Hepatitis B Surface Antigen (HBsAg) Levels and HBV Genotypes B/C are Associated with Persistently Low HBsAg in HBeAg+ Patients Treated with Tenofovir Disoproxil Fumarate (TDF)       Reported by Jules Levin 22nd Conference of the Asian Pacific Association for the Study of the Liver (APASL) February 16-19, 2012 Taipei, Taiwan   S Fung1, E Gane2, IM Jacobson3, P Dinh4, R Ebrahimi4, LJ Yee4, EB Martins4, P Charuworn4, K Kitrinos4, G Dusheiko5, H Trinh6, S Gordon7, R Flisiak8, EJ Heathcote1 and P Marcellin9 1University of Toronto, Toronto, ON, Canada; 2Auckland City Hospital, Auckland, New Zealand; 3Weill Medical College of Cornell University, New York, NY, USA; 4Gilead Sciences, Foster City, CA, USA; 5Royal Free Hospital, London, UK; 6San Jose Gastroenterology, San Jose, CA, USA; 7Henry Ford Medical Center, Detroit, MI, USA; 8Medical University of Bialystok, Bialystok, Poland; 9Hopital Beaujon, University of Paris, Clichy, France Introduction   · HBsAg loss has been studied and is associated with improved prognosis1-6 - HBsAg loss in 11% of patients in pivotal TDF study GS-US-174-0103 over 5 years2 - We have analyzed characteristics of those who have had HBsAg loss compared to those who have not lost HBsAg [See Marcellin et al. Poster PP09-042]3 · However, it is still not known why some individuals achieve significant HBsAg declines in the absence of HBsAg loss (persistently low HBsAg) · Other individuals maintain persistently high levels of HBsAg despite treatment - It is unclear what factors differentiate the patients who achieve persistently low HBsAg from those with persistently high HBsAg   Objective   · To evaluate in HBeAg+ patients whether pre-treatment characteristics are associated with persistently low HBsAg in the absence of HBsAg loss   Methods   · Data analyzed from TDF study GS-US-174-01037 - HBeAg-positive patients - 266 patients enrolled · Patients received TDF or ADV for 48 weeks, followed by TDF for another 192 weeks (Figure 1) · The present analyses are based on data through year 4   · Quantitative HBsAg levels - Abbott Architect assay (Abbott Park, Illinois, USA) · Definitions based on an "area under the curve" approach (Figure 2) - Low HBsAg · HBsAg < 2,000 IU/mL for at least 70% of the time over 192 weeks of therapy - High HBsAg · HBsAg ≥ 10,000 IU/mL for at least 70% of the time over 192 weeks of therapy - Definition allows for fluctuation and variability in HBsAg levels   *Individuals who met the high HBsAg and low HBsAg levels maintained these levels for ≥ 70% of the time over 192 weeks. · Univariable associations: - Odds Ratios (ORs), p-values and 95% C.I.s calculated · Multivariable associations - Forward selection logistic regression - Variable entry criteria set at α=0.10 - Standard statistic measurements calculated · Odds Ratios (ORs) · p-value · 95% Confidence Interval (95% C.I.)