Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures.
OBJECTIVE:: The efficacy of pre-exposure prophylaxis (PrEP) in HIV will diminish with poor adherence; pharmacologic measures of drug exposure have proven critical to PrEP trial interpretation. We assessed drug exposure in hair against other pharmacologic and more routinely used measures to assess pi...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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Lippincott Williams and Wilkins
2015
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| _version_ | 1797103012040146944 |
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| author | Baxi, S Liu, A Bacchetti, P Mutua, G Sanders, E Kibengo, F Haberer, J Rooney, J Hendrix, C Anderson, P Huang, Y Priddy, F Gandhi, M |
| author_facet | Baxi, S Liu, A Bacchetti, P Mutua, G Sanders, E Kibengo, F Haberer, J Rooney, J Hendrix, C Anderson, P Huang, Y Priddy, F Gandhi, M |
| author_sort | Baxi, S |
| collection | OXFORD |
| description | OBJECTIVE:: The efficacy of pre-exposure prophylaxis (PrEP) in HIV will diminish with poor adherence; pharmacologic measures of drug exposure have proven critical to PrEP trial interpretation. We assessed drug exposure in hair against other pharmacologic and more routinely used measures to assess pill-taking. DESIGN:: Participants were randomized to placebo, daily PrEP, or intermittent PrEP to evaluate safety and tolerability of daily versus intermittent tenofovir/emtricitabine (TFV/FTC) in 2 phase II PrEP clinical trials conducted in Africa. Different measures of drug exposure, including self-report, medication event monitoring system (MEMS)-caps openings, and TFV/FTC levels in hair and other biomatrices were compared. METHODS:: At weeks 8 and 16, self-reported pill-taking, MEMS-caps openings, and TFV/FTC levels in hair, plasma, and peripheral blood mononuclear cells (PBMCs) were measured. Regression models evaluated predictors of TFV/FTC concentrations in the 3 biomatrices; correlation coefficients between pharmacologic and nonpharmacologic measures were calculated. Both trials were registered on ClinicalTrials.gov (NCT00931346/NCT00971230). RESULTS:: Hair collection was highly feasible and acceptable (100% in week 8; 96% in week 16). In multivariate analysis, strong associations were seen between pharmacologic measures and MEMS-caps openings (all P < 0.001); self-report was only weakly associated with pharmacologic measures. TFV/FTC hair concentrations were significantly correlated with levels in plasma and PBMCs (correlation coefficients, 0.41-0.86, all P < 0.001). CONCLUSIONS:: Measuring TFV/FTC exposure in small hair samples in African PrEP trials was feasible and acceptable. Hair levels correlated strongly with PBMC, plasma concentrations, and MEMS-caps openings. As in other PrEP trials, self-report was the weakest measure of exposure. Further study of hair TFV/FTC levels in PrEP trials and demonstration projects to assess adherence/exposure is warranted. |
| first_indexed | 2024-03-07T06:13:58Z |
| format | Journal article |
| id | oxford-uuid:f07a29d7-ef34-4462-b2f3-b5e93a8242ae |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:13:58Z |
| publishDate | 2015 |
| publisher | Lippincott Williams and Wilkins |
| record_format | dspace |
| spelling | oxford-uuid:f07a29d7-ef34-4462-b2f3-b5e93a8242ae2022-03-27T11:48:14ZComparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f07a29d7-ef34-4462-b2f3-b5e93a8242aeEnglishSymplectic Elements at OxfordLippincott Williams and Wilkins2015Baxi, SLiu, ABacchetti, PMutua, GSanders, EKibengo, FHaberer, JRooney, JHendrix, CAnderson, PHuang, YPriddy, FGandhi, MOBJECTIVE:: The efficacy of pre-exposure prophylaxis (PrEP) in HIV will diminish with poor adherence; pharmacologic measures of drug exposure have proven critical to PrEP trial interpretation. We assessed drug exposure in hair against other pharmacologic and more routinely used measures to assess pill-taking. DESIGN:: Participants were randomized to placebo, daily PrEP, or intermittent PrEP to evaluate safety and tolerability of daily versus intermittent tenofovir/emtricitabine (TFV/FTC) in 2 phase II PrEP clinical trials conducted in Africa. Different measures of drug exposure, including self-report, medication event monitoring system (MEMS)-caps openings, and TFV/FTC levels in hair and other biomatrices were compared. METHODS:: At weeks 8 and 16, self-reported pill-taking, MEMS-caps openings, and TFV/FTC levels in hair, plasma, and peripheral blood mononuclear cells (PBMCs) were measured. Regression models evaluated predictors of TFV/FTC concentrations in the 3 biomatrices; correlation coefficients between pharmacologic and nonpharmacologic measures were calculated. Both trials were registered on ClinicalTrials.gov (NCT00931346/NCT00971230). RESULTS:: Hair collection was highly feasible and acceptable (100% in week 8; 96% in week 16). In multivariate analysis, strong associations were seen between pharmacologic measures and MEMS-caps openings (all P < 0.001); self-report was only weakly associated with pharmacologic measures. TFV/FTC hair concentrations were significantly correlated with levels in plasma and PBMCs (correlation coefficients, 0.41-0.86, all P < 0.001). CONCLUSIONS:: Measuring TFV/FTC exposure in small hair samples in African PrEP trials was feasible and acceptable. Hair levels correlated strongly with PBMC, plasma concentrations, and MEMS-caps openings. As in other PrEP trials, self-report was the weakest measure of exposure. Further study of hair TFV/FTC levels in PrEP trials and demonstration projects to assess adherence/exposure is warranted. |
| spellingShingle | Baxi, S Liu, A Bacchetti, P Mutua, G Sanders, E Kibengo, F Haberer, J Rooney, J Hendrix, C Anderson, P Huang, Y Priddy, F Gandhi, M Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures. |
| title | Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures. |
| title_full | Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures. |
| title_fullStr | Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures. |
| title_full_unstemmed | Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures. |
| title_short | Comparing the Novel Method of Assessing PrEP Adherence/Exposure Using Hair Samples to Other Pharmacologic and Traditional Measures. |
| title_sort | comparing the novel method of assessing prep adherence exposure using hair samples to other pharmacologic and traditional measures |
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