A randomized clinical pharmacokinetic trial of Tenofovir in blood, plasma and urine in adults with perfect, moderate and low PrEP adherence: the TARGET study

Abstract Background Tenofovir disoproxil fumarate (TDF) is key component of pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) for HIV, but existing tools to monitor drug adherence are often inaccurate. Detection of tenofovir (TFV) in accessible biological samples, such as fingerprick blood, urine or oral fluid samples could be a novel objective measure of recent TDF adherence. To measure TFV concentrations associated with different levels of TDF adherence, we designed a randomized clinical trial to assess the blood, urine and oral fluid concentrations of TFV in adults with perfect, moderate and low drug adherence. Methods/design A randomized, open-label, clinical pharmacokinetic study of tenofovir in healthy adult volunteers without HIV or Hepatitis B infection in Thailand. Consenting, eligible participants are randomized (1:1:1) among three groups to receive a controlled number of TDF (300 mg) doses in a combination pill with emtricitabine (FTC, 200 mg) for six weeks. Participants in Group 1 receive a single TDF/FTC tablet once daily (Perfect adherence); Group 2 receive a single TDF/FTC tablet 4 times/week (Moderate adherence); and Group 3 receive a single TDF/FTC tablet 2 times/week (Low adherence). Blood, plasma, urine and oral fluid samples are collected for drug measurement during three study phases: (i) initial 6-week treatment phase; (ii) intensive 24-h blood sampling phase after 6 weeks; (iii) 4-week washout phase. Thirty adults with evaluable pharmacokinetic samples (10 per group) will be enrolled [based on ensuring 25% precision in pharmacokinetic parameter estimates]. Pre-dose drug concentrations during the treatment phase will be descriptive and comparisons between groups performed using a Kruskal-Wallis test. A non-compartmental pharmacokinetic analysis will be performed on the intensive sampling data at Week 7 and the time course of TFV washout in the difference biological matrices will be reported based on the detected concentrations following drug cessation. Discussion The results of this randomized trial will define the target concentration thresholds of TFV in blood, urine and oral fluid that can distinguish between different levels of TDF adherence. Such adherence ‘benchmarks’ can be applied to real-time drug testing and novel point-of-care tests to identify individuals with poor PrEP or ART adherence. Trial registration ClinicalTrials.gov Identifier NCT03012607

Urine Tenofovir Concentrations Correlate With Plasma and Relate to Tenofovir Disoproxil Fumarate Adherence: A Randomized, Directly Observed Pharmacokinetic Trial (TARGET Study).

BackgroundDirect measurement of tenofovir (TFV) in urine could be an objective measure to monitor adherence to preexposure prophylaxis (PrEP) or TFV-based antiretroviral therapy (ART).MethodsWe conducted a 3-arm randomized, pharmacokinetic study of tenofovir disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg among adults living with human immunodeficiency virus. Participants were randomized to receive controlled TDF/FTC dosing as (1) "perfect" adherence (daily); (2) "moderate" adherence (4 doses/week); or (3) "low" adherence (2 doses/week). We obtained trough spot urine and plasma samples during a 6-week directly observed therapy period and a 4-week washout period. TFV concentrations were compared between adherence arms using 1-way analysis of variance.ResultsAmong 28 participants, the median age was 33 years and 16 (57%) were male. Correlation between TFV plasma and urine concentrations was strong (ρ = 0.78; P < .0001). Median (interquartile range) steady-state trough TFV concentrations (ng/mL) for perfect, moderate, and low TDF adherence were 41 (26-52), 16 (14-19), and 4 (3-5) in plasma; and 6480 (3940-14 300), 3405 (2210-5020), and 448 (228-675) in urine. Trough TFV concentrations at steady state were significantly different between the 3 adherence arms for plasma (P < .0001) and urine (P = .0002). Following drug cessation, TFV concentrations persisted longer in urine than plasma samples. Washout urine TFV concentrations and time to undetectable concentrations did not differ between the 3 randomized adherence groups.ConclusionsUrine TFV concentrations can inform interpretation of novel point-of-care urine-based TFV assays to assess recent TDF adherence.Clinical trials registrationNCT0301260

Structural and Functional Studies on a 3′-Epimerase Involved in the Biosynthesis of dTDP-6-deoxy‑d‑allose

Unusual deoxy sugars are often attached to natural products such as antibiotics, antifungals, and chemotherapeutic agents. One such sugar is mycinose, which has been found on the antibiotics chalcomycin and tylosin. An intermediate in the biosynthesis of mycinose is dTDP-6-deoxy-d-allose. Four enzymes are required for the production of dTDP-6-deoxy-d-allose in <i>Streptomyces bikiniensis</i>, a soil-dwelling microbe first isolated from the Bikini and Rongelap atolls. Here we describe a combined structural and functional study of the enzyme ChmJ, which reportedly catalyzes the third step in the pathway leading to dTDP-6-deoxy-d-allose formation. Specifically, it has been proposed that ChmJ is a 3′-epimerase that converts dTDP-4-keto-6-deoxyglucose to dTDP-4-keto-6-deoxyallose. This activity, however, has never been verified in vitro. As reported here, we demonstrate using ¹H nuclear magnetic resonance that ChmJ, indeed, functions as a 3′-epimerase. In addition, we determined the structure of ChmJ complexed with dTDP-quinovose to 2.0 Å resolution. The structure of ChmJ shows that it belongs to the well-characterized “cupin” superfamily. Two active site residues, His 60 and Tyr 130, were subsequently targeted for study via site-directed mutagenesis and kinetic analyses, and the three-dimensional architecture of the H60N/Y130F mutant protein was determined to 1.6 Å resolution. Finally, the structure of the apoenzyme was determined to 2.2 Å resolution. It has been previously suggested that the position of a conserved tyrosine, Tyr 130 in the case of ChmJ, determines whether an enzyme in this superfamily functions as a mono- or diepimerase. Our results indicate that the orientation of the tyrosine residue in ChmJ is a function of the ligand occupying the active site cleft

Working Together to Define Antibiotic Appropriateness: Point Prevalence Survey in 47 Intensive Care Units from 12 US Hospitals, Partnership for Quality Care, March 2017

Abstract Background: A national assessment of antibiotic appropriateness in intensive care units (ICUs) with benchmarking was performed to assist antibiotic stewardship programs (ASPs) identify improvement opportunities. Methods: A Centers for Disease Control and Prevention tool was adapted by an expert panel from the Partnership for Quality Care (PQC), a coalition dedicated to high quality care in US hospitals, to validate appropriate antibiotic use measurement via a point prevalence survey on a single day. Data were collected by ASP personnel at each hospital, de-identified and submitted in aggregate to PQC for benchmarking. Hospitals identified reasons for inappropriate antibiotic use by category and antibiotics misused. Results: Forty-seven ICUs from 12 PQC hospitals participated: California (2), Florida (2), Massachusetts (3), Minnesota (1), and New York (4). Most hospitals identified as teaching (83%) with 252-1550 bed size (median: 563) and 20–270 licensed ICU beds (median: 70). All hospitals reported a formal ASP. On March 1, 2017, 362 (54%) of 667 patients in participating ICUs were on antibiotics (range: 8-81 patients); 1 patient was not assessed. Of the remaining 361 antibiotic regimens, 112 (31%) were identified as inappropriate from among all 12 hospitals (range: 9-82%) (figure). The table displays inappropriate antibiotic use by ICU type. Reasons for inappropriate use included unnecessarily broad spectrum of activity (29%), duration longer than necessary (21%), and treatment of a non-infectious syndrome (19%). The antibiotic most commonly misused was vancomycin in 7 (58%) hospitals. Conclusion: Up to 80% of antibiotic use in some ICUs is inappropriate, underscoring the need for ASP interventions, standardized assessment tools and benchmarking. Strategies should focus on de-escalation of broad-spectrum antibiotics and reducing duration of therapy. Disclosures D. W. Kubiak, Shionogi: Consultant, Consulting fee. Astellas Pharma: Consultant, Consulting fe

Comorbidities in pulmonary tuberculosis cases in Puducherry and Tamil Nadu, India: Opportunities for intervention

<div><p>Background</p><p>We aimed to define characteristics of TB patients in Puducherry and two districts of Tamil Nadu, India and calculate the population attributable fractions (PAF) of TB from malnutrition and alcohol.</p><p>Methods</p><p>New smear-positive TB cases were enrolled into the Regional Prospective Observational Research for Tuberculosis (RePORT India) cohort. Census and National Family Health Survey data were used for comparisons.</p><p>Results</p><p>Data were analyzed for 409 participants enrolled between May 2014-June 2016; 307 (75.1%) were male, 60.2% were malnourished (body mass index [BMI] <18.5 kg/m²), and 29.1% severely malnourished (BMI <16). “Hazardous” alcohol use (based on AUDIT-C score) was reported by 155/305 (50.8%) of males. Tuberculosis cases were more likely than the Puducherry population to be malnourished (62.6% v 10.2% males and 71.7% v 11.3% of females; both p<0.001), and male cases were more likely to use alcohol than male non-cases (84.4% v 41%; p < .001). The PAF of malnutrition was 57.4% in males and 61.5% in females; the PAF for alcohol use was 73.8% in males and 1.7% in females.</p><p>Conclusions</p><p>Alcohol use in men and malnutrition are helping drive the TB epidemic in Southern India. Reducing the TB burden in this population will require efforts to mitigate these risk factors.</p></div

Characteristics of TB patients in RePORT cohort, Puducherry and Tamil Nadu, (2014–16).

<p>Characteristics of TB patients in RePORT cohort, Puducherry and Tamil Nadu, (2014–16).</p