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)

Citation: Castillo-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. 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). J Antimicrob Chemother. 2016 Jun;71(6):1609-18. doi: 10.1093/jac/dkw005. Epub 2016 Feb 17. PMID: 26892777. PMCID: PMC4867099.

Access full article:

https://www.ncbi.nlm.nih.gov/pubmed/26892777

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.

J Antimicrob Chemother. 2016 Jun;71(6):1609-18. doi: 10.1093/jac/dkw005.
PMID: 26892777

Categories

CRS
Topics

Clinical Trials

A5329: Interferon –Free Therapy for Chronic Hepatitis C...

A5329 is a study for people who are infected with both HIV and the Hepatitis C virus (HCV) and have never taken Hepatitis C...

Read More

A5349: Rifapentine-containing treatment shortening regimens...

The purpose of this study is to determine whether one or two four-month regimens of tuberculosis treatment are as effective as a...

Read More

ACTIV-2/A5401: Adaptive Platform Treatment for Outpatients...

Rationale: There is an urgent need for a platform to rapidly evaluate therapies in the outpatient setting, to prevent disease...

Read More

A5274: REMEMBER, Reducing Early Mortality and Early...

This study is being done in people who are starting HIV treatment and who live in areas where the TB infection rate is high. The...

Read More

A5288: MULTIOCTAVE, Management Using the Latest Technologies...

The study is being done to: test a strategy of using a resistance test to choose anti-HIV drugs. Resistance tests look at the...

Read More