A Randomised, Open-label Trial to Assess the Safety and Efficacy of Switching to Tenofovir-emtricitabine or Abacavir-lamivudine: The STEAL Study

Inclusion Criteria:

• documented HIV infection
• age at least 18 years
• stable (≥ to 12 weeks) ART including at least two NRTIs, currently well tolerated, with no plan to change any other component of the ART regimen at or after baseline
• HIV RNA < 50 copies/mL plasma for the preceding 12 weeks
• GFR ≥ 70 mL/min/1.73m2 (estimated by the abbreviated MDRD equation23 estimated GFR = 186 x ([SCR/88.4]-1.154) x age-0.203 x (0.742 if female) x (1.210 if African-American)
• provision of written, informed consent

Exclusion Criteria:

• HLA-B*5701 positive at screening OR evidence of previous ABC hypersensitivity OR clinical failure in participants taking abacavir for at least 30 days
• current therapy comprising triple NRTI therapy alone
• current use of ABC/3TC FDC (Kivexa) or TDF/FTC FDC (Truvada)
• history of non-traumatic osteoporotic fracture
• prior hypersensitivity or intolerance to ABC, 3TC, TDF or FTC
• prior clinical failure to a regimen containing ABC or TDF
• prior use of TDF for control of previously active hepatitis B (HBsAg+ or HBV DNA+) in patients likely to be resistant to 3TC/FTC
• current therapy including unboosted atazanavir
• concurrent use of aminoglycosides, IV amphotericin B, cidofovir, cisplatin, foscarnet, IV pentamidine, probenecid, adefovir or immunomodulatory agents
• clinical evidence of cirrhosis (e.g. smooth liver, no features of portal hypertension)

• creatinine clearance < 50 mL/min (estimated by the Cockcroft-Gault equation)18,19

  • Male: (140 - age in years) x (wt in kg) = CLCr (mL/min) 0.814 x (serum creatinine in µmol/L)
  • Female:(140 - age in years) x (wt in kg) x 0.85 = CLCr (mL/min) 0.814 x (serum creatinine in µmol/L)