icon-    folder.gif   Conference Reports for NATAP  
  17th CROI
Conference on Retroviruses
and Opportunistic Infections
San Francisco CA
February 16-19, 2010
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5-Year Tenofovir Therapy Is Associated with Maintained HBV Response and Renal Toxicity in HIV/HBV Co-infected Patients
  Reported by Jules Levin
CROI Feb 16-19 SF
Theodora de Vries-Sluijs*1, J Reijnders1, B Hansen1, H Zaaijer2, J Prins2, M Schutten1, R de Man1, H Janssen1, and M van der Ende1 1Erasmus Med Ctr, Rotterdam, The Netherlands and 2Academic Med Ctr, Amsterdam, The Netherlands

Background: We investigated the long-term efficacy and renal safety of tenofovir disoproxil fumarate (TDF) administered as a part of anti-retroviral therapy in a large cohort of HIV/HBV co infected patients.
Methods: 102 HIV/HBV co infected patients who received TDF (245 mg daily) for at least 6 months were included in this multicenter cohort study. Patients were monitored every 6 months with standard virologic and biochemical assessments. Virologic response (VR) was defined as serum HBV DNA <116 copies/mL. Screening for resistance was performed at baseline in lamivudine (LAM)-experienced patients or in case of virologic breakthrough by direct sequencing. The glomerular filtration rate (eGFR) in mL/min/1.73 m2 was calculated using the Modification in Diet in Renal Disease (MDRD) equation, based on the serum creatinine, age, sex and race. Renal impairment was defined as eGFR less than 60 mL/min/1.73 m2.
Results: Seventy-nine (77%) patients had a detectable viral load at baseline. Forty-eight (61%) of 79 patients were LAM-experienced and in 33 (69%) patients LAM-resistance could be detected at baseline. Median follow-up was 56 (range: 10 to 84) months. For HBeAg-positive patients (n = 66), the cumulative probability of achieving VR at 1, 2, 3, 4, and 5 years of treatment was 41, 74, 82, 84, and 88%, respectively. There was no significant difference between patients with or without LAM-resistance at baseline (P =0.13). HBeAg loss and HBsAg loss rates increased to 40% and 10% after 5 years of TDF therapy. For HBeAg-negative patients (n = 13), the cumulative probability of achieving VR at 1, 2, and 4 years of treatment was 54, 72, and 100%, respectively. HBsAg loss occurred in 8%. Twenty-three (23%) subjects (all HBeAg-) had an undetectable viral load at baseline. Median follow-up was 53 (range: 8 to 83) months. During follow-up 22 (96%) subjects maintained virologic response and 2 (9%) patients showed HBsAg loss. Overall, 4 of 102 patients experienced a virologic breakthrough, yet none of them demonstrated TDF-resistant mutations. The mean serum creatinin increased from 0.87 ± 0.17 mg/dL at baseline to 0.93 ± 0.22 mg/dL at the end of follow-up (P =0.002).
Conclusion: TDF is an effective anti-HBV agent through five years of therapy and is not influenced by the presence of LAM resistance. However, during treatment with TDF serum creatinin levels significantly increased, which necessitates long-term follow-up to determine the consequences of these side effects.