Aims: In CHB patients with LAM-R, TDF has shown efficacy comparableto FTC/TDF and no detectable TDF resistance at 2 years. The final5 year efficacy and safety results from this trial are presented.Methods: CHB patients on LAM with HBV DNA >3 log10 IU/mL andwith documented LAM-R were randomized (1:1) to TDF or FTC/TDFand followed for 5 years.Results: Two hundred eighty patients were randomized; 232 (83%)completed 5 years of treatment. At baseline, mean age was 47 years,most were male (75%) and non-Asian (66%); 53% were HBeAgnegative. Mean HBV DNA was 5.7 log10 IU/mL and 42% had ALT≤ULN at baseline. At Year 5, virologic, serologic, and biochemicalresponses were similar among groups, and remained stable. Ninepatients (4-TDF, 5-FTC/TDF) discontinued due to an adverse event,including increased serum creatinine in 1 patient. For both groupscombined, confirmed renal safety endpoints over 5 years were: CrCL<50 mL/min in 19 (6.8%) patients (12 requiring dose modification),increases in serum creatinine of ≥0.3 and ≥0.5 mg/dL from baselinein 21 (7.5%) and 2 (0.7%) patients, respectively, and serum phosphorus<2 mg/dL in 3 (1.1%) patients. Mean declines in BMD (g/cm2)from baseline for hip and spine BMD, respectively, were 1.7% and1.5% at Year 2, and 2.5%, and 1% at Year 5. Seven patientsexperienced fracture (all except 1 were trauma-related). No TDF resistancewas detected through 5 years by population sequencing.Conclusions: In LAM R patients with CHB treated for 5 years withTDF, a high rate of HBV DNA suppression was achieved and maintainedwith no detectable TDF resistance. There is no apparent ad advantageof combination FTC/TDF in this population. Renal eventsassociated with TDF occurred in up to 7.5% of patients, and averagelosses in bone mineral density of 1 2.5% were observed.