Clinical trial NCT02012621: Quantifying Drug Adherence and Drug Exposure to Antiretroviral Therapy
Official title: Quantifying Drug Adherence and Drug Exposure to Antiretroviral Therapy.
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: HIV/AIDS
Keywords: HIV/AIDS
Adherence
Tenofovir
Dried Blood Spots
Lead sponsor: University of Colorado, Denver
Sponsor class: OTHER
First posted: 2013-12-16
Enrollment: 807
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: HIV-infected individuals who are taking tenofovir.

Brief summary: The purpose of this study is to evaluate cumulative exposure to tenofovir diphosphate (TFV-DP) using dried blood spots (DBS) in treated HIV-infected patients who are receiving a TFV-based regimen. Using DBS will allow the investigators to assess this simple method to measure drug exposure in the clinical setting. The investigators hypothesize that TFV-DP levels will be lowest in individuals with a detectable viral load and highest in those with viral suppression.

Detailed description: Antiretroviral drug exposure is directly linked to individual host factors which include age, weight, diet, and genetics. However, the main factor impacting long-term drug exposure is drug adherence. Adherence is a strong predictor of HIV treatment outcomes, but measuring adherence is difficult due to the inaccuracy of self-reporting and other commonly used monitoring methods. To date, no gold standard measure to monitor antiretroviral exposure and adherence has been applied in clinical practice. Tenofovir (TFV) and its active metabolite, tenofovir diphosphate (TFV-DP), have distinctive pharmacological characteristics that make them ideal candidates for drug adherence and exposure monitoring. The long half life (\~14-17 days) of TFV-DP in red blood cells (RBC) are properties well suited for monitoring average dose exposure over time. Based on these, the investigators propose that RBC levels of TFV-DP are an accurate and precise measure of long-term drug exposure in HIV-infected individuals. In addition, the investigators aim to quantify TFV-DP in dried blood spots (DBS) as a simple method to measure drug exposure.

This is an observational, 48-week prospective study of HIV-infected individuals treated with TFV in which the investigators will compare DBS TFV-DP levels in virologically suppressed vs. non-suppressed individuals and evaluate the utility of TFV-DP in DBS to predict virologic failure and also drug toxicity. To accomplish this, the investigators will approach HIV-infected patients currently taking TFV (which is being prescribed by a primary care physician) and who present to the clinic for regular HIV care. After informed consent is obtained, the investigators will collect extra blood samples for DBS TFV-DP and obtain information on drug adherence. The investigators will also collect extra blood samples for DBS TFV-DP at each subject's subsequent visit for approximately 3 visits in a 48 week period of time.

Eligibility criteria: Inclusion Criteria:

* HIV-infected individual.
* 18 years and older.
* Taking tenofovir.
* Blood drawn during regular clinic visit.

Exclusion Criteria:

* Refusal to participate.
* Pregnancy.
* Inability to provide informed consent.

Primary outcomes:
measure: Adjusted Odds Ratio of Level of Tenofovir-diphosphate (TFV-DP) in Dried Blood Spots (DBS) Associated With Odds of HIV Viral Suppression at All Study Visits
timeFrame: Up to 48 Weeks
measure: Adjusted Odds Ratio of Three-month Self-reported Adeherence Associated With Odds of HIV Viral Suppression at All Study Visits
timeFrame: Up to 48 Weeks
measure: Adjusted Odds Ratio of Level of Tenofovir-diphosphate (TFV-DP) in Dried Blood Spots (DBS) Associated With Odds of HIV Viral Suppression at Next Study Visit
timeFrame: Up to 48 Weeks
Secondary outcomes:
Other outcomes:
Locations:
city: Aurora
country: United States
facility: University of Colorado-Anschutz Medical Campus
state: Colorado
Study officials:
affiliation: University of Colorado, Denver
name: Jose R. Castillo-Mancilla, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Morrow M, MaWhinney S, Coyle RP, Coleman SS, Gardner EM, Zheng JH, Ellison L, Bushman LR, Kiser JJ, Anderson PL, Castillo-Mancilla JR. Predictive Value of Tenofovir Diphosphate in Dried Blood Spots for Future Viremia in Persons Living With HIV. J Infect Dis. 2019 Jul 19;220(4):635-642. doi: 10.1093/infdis/jiz144.
citation: Castillo-Mancilla JR, Morrow M, Coyle RP, Coleman SS, Gardner EM, Zheng JH, Ellison L, Bushman LR, Kiser JJ, Mawhinney S, Anderson PL. Tenofovir Diphosphate in Dried Blood Spots Is Strongly Associated With Viral Suppression in Individuals With Human Immunodeficiency Virus Infections. Clin Infect Dis. 2019 Apr 8;68(8):1335-1342. doi: 10.1093/cid/ciy708.
citation: Castillo-Mancilla J, Seifert S, Campbell K, Coleman S, McAllister K, Zheng JH, Gardner EM, Liu A, Glidden DV, Grant R, Hosek S, Wilson CM, Bushman LR, MaWhinney S, Anderson PL. Emtricitabine-Triphosphate in Dried Blood Spots as a Marker of Recent Dosing. Antimicrob Agents Chemother. 2016 Oct 21;60(11):6692-6697. doi: 10.1128/AAC.01017-16. Print 2016 Nov.