16th International HIV Drug Resistance Workshop 12-16 June 2007, Barbados

CHANGES IN THE REGIONAL PREVALENCE OF HIV-1 DRUG RESISTANCE-ASSOCIATED MUTATIONS AND IN THE PREVALENCE OF NON-CLADE B SUB TYPES IN ANTIRETROVIRAL THERAPY-NAÏVE HIV-INFECTED PATIENTS IN THE UNITED STATES FROM 2000–2006

Antivir Ther. 2007; 12:S54 (abstract no. 47)

LL Ross, V Williams, B Wine, C Vavro, C Craig, D McClernon, M Tisdale, R Balu, T Lancaster, J Horton, K Pappa and ER Lanier
GlaxoSmithKline, Research Triangle Park, NC, USA

BACKGROUND: Pre-existing HIV drug resistanceassociated mutations (DRM) may increase the likelihood of treatment failure when drugs affected by the DRM are prescribed. We examined changes in overall DRM, by drug class, by subtype prevalence and in the context of geographical distribution over time from 2000–2006, using a large cohort of antiretroviral therapy (ART)-naïve patients undergoing treatment of HIV infection.

METHODS: HIV population-based genotypes and subtypes were analysed from ART-naïve patients from 35 states (and District of Columbia) enrolling into clinical trials. DRM were analysed by 2006 IAS-USA, and by Stanford guidelines. Changes in subtype and DRM frequency over time were analysed by drug class and geographical region. Prevalence overall, and in 2000 and 2006 is presented (range shown in brackets if different).

RESULTS: Prevalence of major IAS-USA DRM (n=2,984, 2000–2006) was 11% (2000/2006: 5/12% [range: 5–15%]). By drug class, NRTI was 4% (2000/2006: 3/4%, [range: 3–6%]), NNRTI 7% (2000/2006: 2/7%, [range: 2–8%]), and PI 3% (2001/2006: 2/2%, [range: 2–5%]). By Stanford, overall DRM was 13% (2000/2006: 6/14% [range: 6–15%]). Subsetting DRM by class, NRTI was 6% (2000/2006: 5/8%), NNRTI 6% (2000/2006: 2/7%), and PI 3% (2001/2006: 2/2%, [range: <1–5%]). By either list, dual-class resistance was 2% (range: <1–3%). By geographical region, the overall IAS-USA DRM for the South was 12% (2000/2006: 4/15%), Northeast 9% (2000/2006: 8/6% [range 0–14]), Midwest 8% (2000/2006: 10/9% [range: 0–25%]), and West 12%(2000/2006: 6/8%, [range: 6–22%]). By Stanford, overall DRM 2000/2006 was 13% 11%, 12%, and 13% for the south, northeast, mid-west and west, respectively. By subtype (n=2,547; 2001–2006), overall prevalence: B: 96%; C: 1.4%; indeterminate: 1%; G: 0.6%; A: 0.4%; and <0.1%: F or chimeric mixes (B or A with D/F/G or B/G, respectively). Non-clade B increased from 4.7–6% from 2001/2006.

CONCLUSIONS: By IAS-USA or Stanford definitions, the number of ART-naïve patients with DRM in this large US cohort increased from 2000–2006, with the greatest increase observed for NNRTI DRM. Regional differences in DRM prevalence were observed, with the highest in the south and west, albeit with yearly variation, suggesting that prescribing patterns may impact these results. Detection of dual-class DRM increased slightly over time. Subtype B was the most common subtype, although nonclade B subtypes increased slightly from 2001–2006.

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2007-06-12
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