Pharmacogenetics of unboosted atazanavir in HIV-infected individuals in resource-limited settings: a sub-study of the AIDS Clinical Trials Group (ACTG) PEARLS study (NWCS 342).

TitlePharmacogenetics of unboosted atazanavir in HIV-infected individuals in resource-limited settings: a sub-study of the AIDS Clinical Trials Group (ACTG) PEARLS study (NWCS 342).
Publication TypeJournal Article
Year of Publication2016
AuthorsCastillo-Mancilla JR, Aquilante CL, Wempe MF, Smeaton LM, Firnhaber C, LaRosa AM, Kumarasamy N, Andrade A, Baheti G, Fletcher CV, Campbell TB, Haas DW, MaWhinney S, Anderson PL
JournalJ Antimicrob Chemother
Volume71
Issue6
Pagination1609-18
Date Published2016 Jun
ISSN1460-2091
Abstract

OBJECTIVES: The multinational PEARLS (ACTG A5175) study, conducted mainly in resource-limited settings, identified an increased treatment failure rate among HIV-infected individuals randomized to once-daily unboosted atazanavir, didanosine-EC, and emtricitabine compared with efavirenz-based regimens. We evaluated associations between selected human genetic polymorphisms and atazanavir pharmacokinetics in PEARLS.

METHODS: Polymorphisms in CYP3A5, ABCB1, SLCO1B1 and NR1I2 were genotyped in PEARLS participants randomized to atazanavir plus didanosine-EC plus emtricitabine in Peru, South Africa and the USA, who also consented to genetic analysis. Non-linear mixed-effects population pharmacokinetic modelling was used to predict atazanavir oral clearance (CL/F) and concentration at 24 h (C24). Atazanavir mono-oxidation metabolites M1 and M2 were quantified from the same single-point plasma sample used to quantify the parent drug. Data were log10 transformed for statistical analysis using unpaired t-tests and one-way ANOVA and are presented as geometric mean (95% CI).

RESULTS: Eighty-four HIV-infected participants were genotyped, including 44 Black Africans or African Americans and 28 women. Median age was 34 years. We identified 56 CYP3A5 expressers and 28 non-expressers. Atazanavir CL/F and C24 did not differ between CYP3A5 expressers and non-expressers: 13.2 (12.1-14.4) versus 12.7 L/h (11.7-13.9), P = 0.61, and 75.3 (46.1-123.0) versus 130.9 ng/mL (86.9-197.2), P = 0.14, respectively. M1/atazanavir and M2/atazanavir ratios were higher in expressers than in non-expressers: 0.0083 (0.0074-0.0094) versus 0.0063 (0.0053-0.0075), P = 0.008, and 0.0065 (0.0057-0.0073) versus 0.0050 (0.0042-0.0061), P = 0.02, respectively.

CONCLUSIONS: Expression of CYP3A5 appears to be associated with increased M1 and M2 atazanavir metabolite formation, without significantly affecting parent compound pharmacokinetics.

DOI10.1093/jac/dkw005
Alternate JournalJ. Antimicrob. Chemother.
PubMed ID26892777
PubMed Central IDPMC4867099
Grant ListK23 AI104315 / AI / NIAID NIH HHS / United States
P30 AI110527 / AI / NIAID NIH HHS / United States
R01 AI077505 / AI / NIAID NIH HHS / United States
UM1 AI068634 / AI / NIAID NIH HHS / United States
UM1 AI068636 / AI / NIAID NIH HHS / United States