[43] EARLY VIROLOGIC FAILURE IN A PILOT STUDY EVALUATING THE EFFICACY OF ABACAVIR, LAMIVUDINE AND TENOFOVIR IN THE TREATMENT naïve HIV-INFECTED PATIENTS

2nd International AIDS Society Conference on HIV Pathogenesis and Treatment

Paris, France - July 13 - 16, 2003

[TITLE:] EARLY VIROLOGIC FAILURE IN A PILOT STUDY EVALUATING THE EFFICACY OF ABACAVIR, LAMIVUDINE AND TENOFOVIR IN THE TREATMENT naïve HIV-INFECTED PATIENTS

[AUTHOR(S):] C Farthing, H Khanlou and V Yeh
AIDS Healthcare Foundation, Los Angeles, CA, USA

IAS Conf HIV Pathog Treat 2003 Jul 13-16;2nd: Abstract No. 43
Antiviral Therapy 2003; 8(Suppl. 1):S195

[ABSTRACT:] Introduction: Previous investigational data using abacavir (ABC), lamuvidine (3TC) and zidovudine has suggested the possibility of triple nucleoside analogue reverse transcriptase inhibitors (NRTI) therapy as an option in the treatment of HIV infection. We performed a pilot study to assess the potency of once-daily ABC+3TC+tenofovir (TDF) in the treatment of HIV-infected naïve patients. CD4 and HIVVL were followed monthly. Patients were considered to be non-responder/failing if there was no reduction in VL by ≥2 log₁₀ by week 8 and/or a rebound in VL after initial suppression. Resistance testing was then obtained.

Results: Twenty patients (pts) naïve to ARVs (3 women and 17 men) were enrolled, of which 3 withdrew from study: 1 with allergy to ABC, 1 discharged due to non-adherence and 1 did not return for follow-up. Mean VL and CD4 count at baseline were 82 381 copies/ml [range: 7650-213486] and 273 cells/mm³ [range: 59-598]. Nine pts had VL>100,000 at baseline. After therapy, the mean VL drop at week 4 and 8 were respectively 14898 and 8 219. From 17 patients, 9 [52%] had VL rebound: 1 at week 4, 6 at week 8 and 2 at week 16. The pts were adherent >95% by pill count. Genotypic analysis showed M184V mutation in 2 pts, M184V+K65R in 1 pt and 6 other samples are pending. Study was prematurely interrupted because of these results.

Conclusions: Although preliminary, these results raise the concern about potency and efficacy of this regimen administered once-daily in HIV treatment naïve pts, particularly those with initial VL >100,000.

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