Dose frequency ranging pharmacokinetic study of tenofovir-emtricitabine after directly observed dosing in healthy volunteers to establish adherence benchmarks (HPTN 066)

Citation: Hendrix CW, Andrade A, Bumpus NN, Kashuba AD, Marzinke MA, Moore A, Anderson PL, Bushman LR, Fuchs EJ, Wiggins I, Radebaugh C, Prince HA, Bakshi RP, Wang R, Richardson P, Shieh E, McKinstry L, Li X, Donnell D, Elharrar V, Mayer KH, Patterson KB.Dose frequency ranging pharmacokinetic study of tenofovir-emtricitabine after directly observed dosing in healthy volunteers to establish adherence benchmarks (HPTN 066). AIDS Res Hum Retroviruses. 2016 Jan;32(1):32-43. doi: 10.1089/AID.2015.0182. Epub 2015 Oct 15.

Access full article:

http://www.ncbi.nlm.nih.gov/pubmed/26414912

Oral preexposure prophylaxis (PrEP) trials report disparate efficacy attributed to variable adherence. HPTN 066 was conducted to establish objective, quantitative benchmarks for discrete, regular levels of adherence using directly observed dosing of tenofovir (TFV) disoproxil fumarate (TDF)/emtricitabine (FTC). Healthy, HIV-uninfected men and women were randomized to one of four oral regimens of fixed-dose TDF 300 mg/FTC 200 mg tablet for 5 weeks with all doses observed: one tablet weekly (one/week), one tablet twice weekly (two/week), two tablets twice weekly (four/week), or one tablet daily (seven/week). Trough serum TFV and FTC, peripheral blood mononuclear cell (PBMC), and CD4(+) TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP) concentrations were determined throughout dosing and 2 weeks after the last dose. Rectosigmoidal, semen, and cervicovaginal samples were collected for drug assessment at end of dosing and 2 weeks later in a subset of participants. The 49 enrolled participants tolerated the regimens well. All regimens achieved steady-state concentrations by the second dose for serum TFV/FTC and by 7 days for PBMC TFV-DP/FTC-TP. Steady-state median TFV-DP predose concentrations demonstrated dose proportionality: one/week 1.6 fmol/10(6) PBMCs, two/week 9.1, four/week 18.8, seven/week, 36.3. Further, TFV-DP was consistently quantifiable 2 weeks after the last dose for the ≥4/week regimens. Adherence benchmarks were identified using receiver operating characteristic curves, which had areas under the curve ≥0.93 for all analytes in serum and PBMCs. Intersubject and intrasubject coefficients of variation (%CV) ranged from 33% to 63% and 14% to 34%, respectively, for all analytes in serum and PBMCs. Steady-state PBMC TFV-DP was established earlier and at lower concentrations than predicted and was the only analyte demonstrating predose concentration dose proportionality. Steady-state daily dosing serum TFV and PBMC TFV-DP was consistent with highly effective PrEP clinical trials. HPTN 066 provides adherence benchmarks for oral TFV/FTC regimens to assist interpreting study outcomes.

AIDS Res Hum Retroviruses. 2016 Jan;32(1):32-43. doi:  0.1089/AID.2015.0182. Epub 2015 Oct 15. PMID: 26414912

Categories

CRS
Topics

Clinical Trials

A5384: A Phase II, Randomized, Open-Label Trial of a...

Study Description A5384 is a trial for people who have or might have tuberculous meningitis (TBM). TBM is an infectious disease...

Read More

A5207, Maintaining Options for Mothers Study (MOMS): A Phase...

A major disadvantage of giving SD NVP is the potential for maternal development of NVP resistance and additional resistance to...

Read More

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

P2026: Pharmacokinetic Properties of Antiretroviral and...

IMPAACT P1026s, the predecessor of this study, was first approved in 2003. P1026s enrolled over 1000 pregnant/postpartum women,...

Read More

A5300B/I2003B/PHOENIX, Protecting Households On Exposure to...

This study will compare the efficacy and safety of 26 weeks of delamanid (DLM) versus 26 weeks of isoniazid (INH) for preventing...

Read More