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)


HIV Prevention


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.

External Link:

Link to article


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.


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).


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.


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



Clinical Trials

A5302:  BioBank for Surrogate Marker Research for TB...

Primary Objective To obtain sputum, serum, urine, and peripheral blood mononuclear cells (PBMCs) for central TB biorepository...

Read More

P1073: Study of Immune Reconstitution Inflammatory Syndrome...

P1073 is a case controlled prospective, clinical, observational and pathogenesis study of HIV-infected infants and children...

Read More

A5321: Decay of HIV-1 Reservoirs in Patients on Long-Term...

The study is being done to try to determine which factors contribute to the persistence of HIV (how long the virus remains) in...

Read More

A5324: A Randomized, Double-Blinded, Placebo-Controlled...

ACTG A5324 is a phase IV randomized, double-blinded, placebo-controlled study to assess the efficacy of adding Maraviroc (MVC)...

Read More

A5314: Effect of LDMTX on Inflammation in HIV-infected...

A5314 is a phase II randomized, double-blind, placebo-controlled 36-week trial that will examine the safety and efficacy of...

Read More