These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Virological responses to atazanavir-ritonavir-based regimens: resistance-substitutions score and pharmacokinetic parameters (Reyaphar study). Author: Pellegrin I, Breilh D, Ragnaud JM, Boucher S, Neau D, Fleury H, Schrive MH, Saux MC, Pellegrin JL, Lazaro E, Vray M. Journal: Antivir Ther; 2006; 11(4):421-9. PubMed ID: 16856615. Abstract: OBJECTIVE: To assess the impact of baseline HIV-1 substitutions, individual pharmacokinetic (PK) parameters (Cmin, Cmax, area under the curve [AUC0-->24 h]) and genotype-inhibitory quotient (GIQ) on virological responses (VR) to atazanavir-ritonavir (300 mg/100 mg)-based highly active antiretroviral therapy (HAART) in 71 antiretroviral-experienced, atazanavir-naive patients in virological failure (VF) on HAART. METHODOLOGY: VR was defined as HIV RNA <1.7 log10 copies/ml at week 12 (W12). A clinically relevant genotype-substitutions score for atazanavir-ritonavir was developed and validated (Reyaphar substitutions score). Previously published substitutions scores were also tested. RESULTS: Patients had a median (Q1; O3) of 6 (3; 8) previous treatment lines during 9 (7; 11) years. Baseline (WO) values were as follows: 262 (187; 435) CD4+/microl, 3.9 (2.6; 4.9) log10 HIV-1 RNA copies/ml, 4 (2; 6) protease substitutions and 3 (1; 4) NRTI-related substitutions. Respective steady-state Cmin, Cmax and AUC0-->24 h were 300 (200; 700) ng/ml, 620 (430; 750) ng/ml and 78,000 (61,000; 94,000) ng.h/ml. At W12, 49% of the patients had VR with a median decrease of -1.2 (-0.5; -2.3) log10 HIV-1 RNA copies/ml. The Reyaphar score included 12 baseline protease substitutions from the International AIDS Society USA list that were associated with poorer VR: L10I/F/R/V, K20I/M/R, L241, M461/L, 154L/M/T/V, L63P, A71I/L/V/T, G73A/C/F/T, V771, V82A/F/S/T, 184V, L90M and the polymorphism substitution Q58E. Comparing <5 versus > or =5 Reyaphar substitutions, the W12-W0 HIV-1 RNA decrease was - 1.4 (-0.7; -2.3) versus -0.5 (-1.2; +0.5) log10 copies/ml (P=0.009) with VR in 63% versus 110% (P<10(-4)), respectively. This score predicted VF at W12 with 46% sensitivity, compared to 33% and 28% for the ANRS 2004 and 2005 scores. PK parameters alone were not associated with VR, but GIQ was associated with virological outcome (P=0.04). 150L, known to be correlated with atazanavir-specific resistance, emerged in 2 (8%) of the 24 failing patients with paired genotypes at WO and VF. CONCLUSIONS: These findings highlight the need to cross-validate genotype-based algorithms to interpret substitution impact on virological outcome using different patient databases before their implementation in routine clinical practice.[Abstract] [Full Text] [Related] [New Search]