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Long-term outcomes of switching to fixed-dose abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC): 3-year results of the BICOMBO study

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Journal of the International AIDS Society201013 (Suppl 4) :P43

  • Published:


  • Cholesterol
  • Glomerular Filtration Rate
  • Treatment Failure
  • Virological Failure
  • Study Therapy


Once-daily fixed-dose combinations ABC/3TC and TDF/FTC are the preferred backbones in Europe [1]. Long-term (>2 years) efficacy and safety of these compounds in simplification strategies are unknown.


333 HIV-1-infected adults on 3TC-containing triple regimens with <200 copies/mL for at least 6 months had their NRTI backbone randomly switched to either ABC/3TC or TDF/FTC. Pre-planned results at 1 year have been already published [2]. Treatment failure (defined as virological failure, discontinuation of study therapy, withdrawal of consent, lost to follow-up, progression to AIDS, or death), virological failure (defined as confirmed plasma HIV-1 RNA >200 copies/mL), adverse events, and changes in CD4 cells, fasting plasma lipids, glomerular filtration rate (GFR) (Cockcroft-Gault), and transaminases at 3 years were compared between arms.


Treatment failure increased from 32 (19%) to 58 (35%) patients on ABC/3TC and from 22 (13%) to 61 (37%) patients on TDF/FTC at 1 and 3 years, respectively (HR for ABC/3TC treatment failure at 3 years 0.99, 95% CI 0.69-1.41). The most common reasons for treatment failure at 3 years in both arms were lost to follow-up/withdrawal of consent (68 patients, 20%) or discontinuation of study drugs for reasons other than adverse events (15 patients, 5%). Total discontinuations due to adverse events increased from 17 at 1-year to 18 patients at 3-years on ABC/3TC and from 9 at 1-year to 10 patients at 3-years on TDF/FTC. Total virological failures increased from 4 at 1-year to 6 patients at 3-years on ABC/3TC while no patient on TDF/FTC developed virological failure at 1-year and through 3-years (HR for ABC/3TC virological failure at 3 years 3.59, 95% CI 0.77-6.42). Change from baseline (mg/dL) in triglycerides (+1 vs -29, P=0.008), total cholesterol (+12 vs -12, P<0.001), LDL-cholesterol (+1 vs -1, P<0.001), and HDL-cholesterol (+3 vs -2, P<0.001) were increased in patients on ABC/3TC compared with decreases in patients on TDF/FTC, although total-to-HDL cholesterol ratio remained almost identical in both arms. There were no significant changes in GFR or transaminases in each arm at 3-years.


From the 1-year analysis, we observed two additional virological failures in patients on ABC/3TC; there were no virological failures in patients on TDF/FTC over 3 years. Through 3 years long-term safety/tolerability was very good. Differential lipid effects between arms were maintained at 3 years.

Authors’ Affiliations

Hospital Clínic-IDIBAPS, Barcelona, Spain
Hospital Principe de Asturias, Alcala de Henares, Spain
Hospital de Bellvitge, L'Hospitalet de Llobregat, Spain
Hospital del Mar, Barcelona, Spain
Hospital de Vall d'Hebron, Barcelona, Spain
Hospital Universitario de Elche, Elche, Spain
Hospital Sant Jaume, Calella, Spain
Hospital Germans Trias i Pujol, Badalona, Spain
Hospital de Mutua de Terrassa, Terrassa, Spain
Hospital Parc Tauli, Sabadell, Spain
Hospital La Paz, Madrid, Spain
Hospital de Mataro, Mataro, Spain
Hospital Universitario de La Princesa, Madrid, Spain
Hospital Son Llatzer, Palma de Mallorca, Spain


  1. European AIDS Clinical Society: Guidelines on the clinical management and treatment of HIV-infected adults in Europe. []
  2. Martínez E, Arranz JA, Podzamczer D, et al: A simplification trial switching from nucleoside reverse transcriptase inhibitors to once-daily fixed-dose aba-cavir/lamivudine or tenofovir/emtricitabine in HIV-1-infected patients with virological suppression. JAIDS. 2009, 51: 290-297.PubMedGoogle Scholar


© Gatell et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.