studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 335A
243
Biochemical, Virologic, and Serologic Response Following
Discontinuation of Long Term TDF Therapy
Maria Buti 1 , David K. Wong 2 , Edward J. Gane 3 , Robert Flisiak 4 ,
Michael P. Manns 5 , Kelly D. Kaita 6 , Lanjia Lin 7 , Kathryn M. Kitrinos
7 , John F. Flaherty 7 , Anuj Gaggar 7 , Patrick Marcellin 8 , Harry
L. Janssen 9 ; 1 Hospital General Universitari Vall d’Hebron and
Ciberehd, Barcelona, Spain; 2 University of Toronto, Toronto, ON,
Canada; 3 Auckland City Hospital, Auckland, New Zealand; 4 Medical
University of Bialystok, Bialystok, Poland; 5 Medical School of
Hannover, Hannover, Germany; 6 University of Manitoba, Winnipeg,
MB, Canada; 7 Gilead Sciences, Inc., Foster City, CA; 8 Hôpital
Beaujon, Clichy, France; 9 ErasmusMC, Rotterdam, Netherlands
Introduction: Treatment of HBV with tenofovir disoproxil fumarate
(TDF) is associated with durable viral suppression, liver
fibrosis improvement, and no documented resistance in a
cohort of patients followed for up to 8 years. We characterized
the responses following treatment discontinuation. Methods:
Patients from 2 phase 3 studies of TDF in HBeAg-negative and
HBeAg-positive patients were followed for up to 24 weeks after
discontinuing TDF. Clinical and laboratory parameters, and
pre-specified requirements to restart therapy were monitored
during the treatment-free follow-up (TFFU) period. Results: To
date, 123 patients entered TFFU with mean duration of 12
weeks and 71 patients completing 24 weeks of TFFU. 98 (80%)
patients were HBeAg negative at the time of TDF withdrawal,
including 21 that seroconverted in the parent study. Serious
adverse events (AEs) were reported in 10 subjects (8%), 7
of which involved ALT elevation, and Grade 3-4 AEs were
observed in 12% of subjects. 89% of patients had increase in
HBV DNA to >69 IU/mL and 28% had Grade 3-4 elevations in
ALT after cessation of TDF. At last TFFU visit, 44 patients (36%)
had normal ALT, 59 (48%) maintained HBV DNA