Abacavir (Ziagen)

Published January 23, 2001; Updated June 2018
Susa Coffey, MD
Selected References
14. Opravil  M, Hirschel  B, Lazzarin  A, Furrer  H, Chave  JP, Yerly  S, Bisset  LR, Fischer  M, Vernazza  P, Bernasconi  E, Battegay  M, Ledergerber  B, G√ľnthard  H, Howe  C, Weber  R, Perrin  L; Swiss HIV Cohort Study.
A randomized trial of simplified maintenance therapy with abacavir, lamivudine, and zidovudine in human immunodeficiency virus infection. J Infect Dis. 2002 May;185(9):1251-60
[PubMed ID: 12001042]
This randomized study evaluated the efficacy and tolerability of continued treatment with protease inhibitor plus nucleoside-analogue combination regimens (n=79) or a change to the simplified regimen of abacavir-lamivudine-zidovudine (n=84) in patients with suppressed human immunodeficiency virus type 1 (HIV-1) RNA for > or = 6 months who did not have the reverse transcriptase 215 mutation. After a median follow-up of 84 weeks, virologic failure was 6% in the continuation and 15% in the simplified group (P=.081). Previous zidovudine monotherapy or dual therapy and archived reverse transcriptase resistance mutations in HIV-1 DNA at baseline were significant predictors of failure. Study treatment was discontinued because of adverse events in 20% of the continuation and 7% of the simplified group (P=.021). Simplification to abacavir-lamivudine-zidovudine significantly decreased nonfasting cholesterol and triglyceride levels; however, this switch strategy carries a risk of virologic failure when treatment history or resistance testing suggest the presence of archived resistance mutations to the simplified regimen.
15. Clumeck  N, Goebel  F, Rozenbaum  W, Gerstoft  J, Staszewski  S, Montaner  J, Johnson  M, Gazzard  B, Stone  C, Athisegaran  R, Moore  S; CNA30017 Study Team.
Simplification with abacavir-based triple nucleoside therapy versus continued protease inhibitor-based highly active antiretroviral therapy in HIV-1-infected patients with undetectable plasma HIV-1 RNA. AIDS. 2001 Aug;15(12):1517-26
[PubMed ID: 11504984]
OBJECTIVE: To assess the antiviral efficacy, safety and adherence in patients switched to an abacavir-containing nucleoside reverse transcriptase inhibitor (NRTI) regimen after long-term HIV-1 RNA suppression with a dual NRTI/protease inhibitor (PI) combination. METHODS: In an open-label, multicentre study, patients receiving 2NRTI plus PI for at least 6 months, with a history of undetectable plasma HIV-1 RNA since the initiation of therapy and plasma HIV-1 RNA < 50 copies/ml at screening, were randomly assigned to replace the PI with abacavir (n = 105) or continue the same treatment (n = 106). Clinical assessments included plasma HIV-1 RNA, chemistry, haematology, lymphocyte counts, and adverse event reports. Adherence to treatment was assessed by patient self-report. RESULTS: A significantly longer time to treatment failure was demonstrated in the abacavir arm compared with the PI arm (P = 0.03) while treatment failure was experienced by significantly more patients in the PI arm: 24 (23%) versus 12 (12%) (P = 0.03). Therapy-limiting toxicity led to treatment failure in eight versus 14 cases in the abacavir and PI arms, respectively, whereas virological rebound was the cause in four versus two cases. Significant reductions in cholesterol and non-fasting triglyceride plasma levels at 48 weeks were observed in the abacavir arm (P < 0.001 andP = 0.035, respectively). The number of patients reporting no difficulty in taking their therapy showed a marked increase from baseline in the abacavir arm. CONCLUSION: The replacement of PI by abacavir in a triple combination regimen following prolonged suppression of plasma HIV-1 RNA provides continued virological suppression, significant improvements in lipid abnormalities and enhanced ease of dosing.