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11th Annual Conference Of The British HIV Association [BHIVA]20–23 April 2005, Burlington Hotel·Dublin·Ireland |
[AUTHOR(S):] NT Annan, S Mandalia, M Bower, M Nelson, B Gazzard
Chelsea and Westminster Hospital, London, UK
BHIVA Conf 2005 Apr 20-23;11:O23
INTRODUCTION: Several cohort studies have suggested increased potency of efavirenz when compared with nevirapine but the 2NN study failed to show this difference. Two possible confounding factors are year of treatment and NA backbone. We evaluate the effect of these factors on NNRTI based regimen success in a large prospectively collected cohort.
METHODS: ART naïve individuals starting NNRTI with dual NA backbone were identified between 1/1/1998–1/7/2004. Treatment failure was defined as switch/discontinuation of NNRTI or documented virological failure (2× VL>500 copies/ml).
RESULTS: 994 patients were identified, 72.7% efavirenz and 27.3% nevirapine. There were no significant differences in gender, age, baseline VL or CD4 count. In univariate analysis, efavirenz was associated with significantly greater virological success (p<0.001). Multivariate analysis showed DDI/TFV(HR6.57, 95%CI 3.88–11.13) and DDI/D4T (HR1.49, 95%CI 1.00–2.22) to be significant independent predictors of failure. Univariate analyses showed the likelihood of success to be almost two fold increase per year (HR1.96, 95%CI 1.81–2.13) since 1998. When controlling for NA backbone and stratifying by year of therapy, there was no significant difference between treatment with nevirapine or efavirenz.
CONCLUSIONS: We have shown in a large NNRTI-experienced cohort, that although in univariate analysis efavirenz appears to have a higher success rate, this is explained by differences in backbone and year. This may explain differences between reported cohort studies and the 2NN study.
PRESENTING AUTHOR: NT Annan
2005-04-20
O23
Copyright © 2005 - British HIV Association (BHIVA) Reproduction of this abstract (other than one copy for personal reference) must be cleared through the BHIVA Organising Secretariat 1 Mountview Court, 310 Friern Barnet Lane, London N20 0LD