Pharmacokinetic-Pharmacodynamic Evidence from a Phase 3 Trial to Support Flat-Dosing of Rifampicin for Tuberculosis.

BACKGROUND: The optimal dosing strategy for rifampicin in treating drug-susceptible tuberculosis (TB) is still highly debated. In the Phase 3 clinical trial Study 31/ACTG 5349 (NCT02410772), all participants in the control regimen arm received 600 mg rifampicin daily as a flat dose. Here, we evaluated relationships between rifampicin exposure and efficacy and safety outcomes. METHODS: We analyzed rifampicin concentration time profiles using population nonlinear mixed-effects models. We compared simulated rifampicin exposure from flat- and weight-banded dosing. We evaluated the effect of rifampicin exposure on stable culture conversion at 6 months, TB-related unfavorable outcomes at 9, 12, and 18 months using Cox proportional hazard models, and all trial-defined safety outcomes using logistic regression. RESULTS: Our model derived rifampicin exposure ranged from 4.57 mg·h/L to 140.0 mg·h/L with a median of 41.8 mg·h/L. Pharmacokinetic simulations demonstrated that flat-dosed rifampicin provided exposure coverage similar to weight-banded dose. Exposure-efficacy analysis (N=680) showed that participants with rifampicin exposure below the median experienced similar hazards of stable culture conversion and TB-related unfavorable outcomes compared to those with exposure above the median. Exposure-safety analysis (N=722) showed that increased rifampicin exposure was not associated with increased grade 3 or higher adverse events, or serious adverse events. CONCLUSIONS: Flat-dosing of rifampicin at 600 mg daily may be a reasonable alternative to the incumbent weight-banded dosing strategy for the standard of care 6-month regimen. Future research should assess the optimal dosing strategy for rifampicin, at doses higher than the current recommendation.

Neural Changes in Children With Residual Speech Sound Disorder After Ultrasound Biofeedback Speech Therapy.

PURPOSE: Children with residual speech sound disorders (RSSD) have shown differences in neural function for speech production, as compared to their typical peers; however, information about how these differences may change over time and relative to speech therapy is needed. To address this gap, we used functional magnetic resonance imaging (fMRI) to examine functional activation and connectivity on adaptations of the syllable repetition task (SRT-Early Sounds and SRT-Late Sounds) in children with RSSD before and after a speech therapy program. METHOD: Sixteen children with RSSD completed an fMRI experiment before (Time 1) and after (Time 2) a speech therapy program with ultrasound visual feedback for /ɹ/ misarticulation. Progress in therapy was measured via perceptual ratings of productions of untreated /ɹ/ word probes. To control for practice effects and developmental change in patterns of activation and connectivity, 17 children with typical speech development (TD) completed the fMRI at Time 1 and Time 2. Functional activation was analyzed using a region-of-interest approach and functional connectivity was analyzed using a seed-to-voxel approach. RESULTS: Children with RSSD showed a range of responses to therapy. After correcting for multiple comparisons, we did not observe any statistically significant cross-sectional differences or longitudinal changes in functional activation. A negative relationship between therapy effect size and functional activation in the left visual association cortex was on the SRT-Late Sounds after therapy, but it did not survive correction for multiple comparisons. Significant longitudinal changes in functional connectivity were observed for the RSSD group on SRT-Early Sounds and SRT-Late Sounds, as well as for the TD group on the SRT-Early Sounds. RSSD and TD groups showed connectivity differences near the left insula on the SRT-Late Sounds at Time 2. CONCLUSION: RSSD and treatment with ultrasound visual feedback may thus be associated with neural differences in speech motor and visual association processes recruited for speech production.

Completion, safety, and efficacy of tuberculosis preventive treatment regimens containing rifampicin or rifapentine: an individual patient data network meta-analysis.

BACKGROUND: 3 months of weekly rifapentine plus isoniazid (3HP) and 4 months of daily rifampicin (4R) are recommended for tuberculosis preventive treatment. As these regimens have not been compared directly, we used individual patient data and network meta-analysis methods to compare completion, safety, and efficacy between 3HP and 4R. METHODS: We conducted a network meta-analysis of individual patient data by searching PubMed for randomised controlled trials (RCTs) published between Jan 1, 2000, and Mar 1, 2019. Eligible studies compared 3HP or 4R to 6 months or 9 months of isoniazid and reported treatment completion, adverse events, or incidence of tuberculosis disease. Deidentified individual patient data from eligible studies were provided by study investigators and outcomes were harmonised. Methods for network meta-analysis were used to generate indirect adjusted risk ratios (aRRs) and risk differences (aRDs) with their 95% CIs. FINDINGS: We included 17 572 participants from 14 countries in six trials. In the network meta-analysis, treatment completion was higher for people on 3HP than for those on 4R (aRR 1·06 [95% CI 1·02-1·10]; aRD 0·05 [95% CI 0·02-0·07]). For treatment-related adverse events leading to drug discontinuation, risks were higher for 3HP than for 4R for adverse events of any severity (aRR 2·86 [2·12-4·21]; aRD 0·03 [0·02-0·05]) and for grade 3-4 adverse events (aRR 3·46 [2·09-6·17]; aRD 0·02 [0·01-0·03]). Similar increased risks with 3HP were observed with other definitions of adverse events and were consistent across age groups. No difference in the incidence of tuberculosis disease between 3HP and 4R was found. INTERPRETATION: In the absence of RCTs, our individual patient data network meta-analysis indicates that 3HP provided an increase in treatment completion over 4R, but was associated with a higher risk of adverse events. Although findings should be confirmed, the trade-off between completion and safety must be considered when selecting a regimen for tuberculosis preventive treatment. FUNDING: None. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

A Standardized Approach for Collection of Objective Data to Support Outcome Determination for Late-Phase Tuberculosis Clinical Trials.

Rationale: We developed a standardized method, possible poor treatment response (PPTR), to help ascertain efficacy endpoints in Study S31/A5349 (NCT02410772), an open-label trial comparing two 4-month rifapentine-based regimens with a standard 6-month regimen for the treatment of pulmonary tuberculosis (TB). Objectives: We describe the use of the PPTR process and evaluate whether the goals of minimizing bias in efficacy endpoint assessment and attainment of relevant data to determine outcomes for all participants were achieved. Methods: A PPTR event was defined as the occurrence of one or more prespecified triggers. Each PPTR required initiation of a standardized evaluation process that included obtaining multiple sputum samples for microbiology. Measurements and Main Results: Among 2,343 participants with culture-confirmed drug-susceptible TB, 454 individuals (19.4%) had a total of 534 individual PPTR events, of which 76.6% were microbiological (positive smear or culture at or after 17 wk). At least one PPTR event was experienced by 92.4% (133 of 144) of participants with TB-related unfavorable outcome and between 13.8% and 14.7% of participants with favorable and not-assessable outcomes. A total of 75% of participants with TB-related unfavorable outcomes had microbiological confirmation of failure to achieve a disease-free cure. Conclusions: Standardized methodologies, such as our PPTR approach, could facilitate unbiased efficacy outcome determinations, improve discrimination between outcomes that are related and unrelated to regimen efficacy, and enhance the ability to conduct pooled analyses of contemporary trials.

Rifapentine With and Without Moxifloxacin for Pulmonary Tuberculosis in People With Human Immunodeficiency Virus (S31/A5349).

BACKGROUND: Tuberculosis (TB) Trials Consortium Study 31/AIDS Clinical Trials Group A5349, an international randomized open-label phase 3 noninferiority trial showed that a 4-month daily regimen substituting rifapentine for rifampin and moxifloxacin for ethambutol had noninferior efficacy and was safe for the treatment of drug-susceptible pulmonary TB (DS-PTB) compared with the standard 6-month regimen. We explored results among the prespecified subgroup of people with human immunodeficiency virus (HIV) (PWH). METHODS: PWH and CD4+ counts ≥100 cells/µL were eligible if they were receiving or about to initiate efavirenz-based antiretroviral therapy (ART). Primary endpoints of TB disease-free survival 12 months after randomization (efficacy) and ≥ grade 3 adverse events (AEs) on treatment (safety) were compared, using a 6.6% noninferiority margin for efficacy. Randomization was stratified by site, pulmonary cavitation, and HIV status. PWH were enrolled in a staged fashion to support cautious evaluation of drug-drug interactions between rifapentine and efavirenz. RESULTS: A total of 2516 participants from 13 countries in sub-Saharan Africa, Asia, and the Americas were enrolled. Among 194 (8%) microbiologically eligible PWH, the median CD4+ count was 344 cells/µL (interquartile range: 223-455). The rifapentine-moxifloxacin regimen was noninferior to control (absolute difference in unfavorable outcomes -7.4%; 95% confidence interval [CI] -20.8% to 6.0%); the rifapentine regimen was not noninferior to control (+7.5% [95% CI, -7.3% to +22.4%]). Fewer AEs were reported in rifapentine-based regimens (15%) than the control regimen (21%). CONCLUSIONS: In people with HIV-associated DS-PTB with CD4+ counts ≥100 cells/µL on efavirenz-based ART, the 4-month daily rifapentine-moxifloxacin regimen was noninferior to the 6-month control regimen and was safe. CLINICAL TRIALS REGISTRATION: NCT02410772.

Sara Alert: An automated symptom monitoring tool for COVID-19 in 11 jurisdictions in the United States, June - August, 2021.

Objectives: Health department personnel conduct daily active symptom monitoring for persons potentially exposed to SARS-CoV-2. This can be resource-intensive. Automation and digital tools can improve efficiency. We describe use of a digital tool, Sara Alert, for automated daily symptom monitoring across multiple public health jurisdictions. Methods: Eleven of the 20 U.S. public health jurisdictions using Sara Alert provided average daily activity data during June 29 to August 30, 2021. Data elements included demographics, communication preferences, timeliness of symptom monitoring initiation, responsiveness to daily messages, and reports of symptoms. Results: Participating jurisdictions served a U.S. population of over 22 million persons. Health department personnel used this digital tool to monitor more than 12,000 persons per day on average for COVID-19 symptoms. On average, monitoring began 3.9 days following last exposure and was conducted for an average of 5.7 days. Monitored persons were frequently < 18 years old (45%, 5,474/12,450) and preferred communication via text message (47%). Seventy-four percent of monitored persons responded to at least one daily automated symptom message. Conclusions: In our geographically diverse sample, we found that use of an automated digital tool might improve public health capacity for daily symptom monitoring, allowing staff to focus their time on interventions for persons most at risk or in need of support. Future work should include identifying jurisdictional successes and challenges implementing digital tools; the effectiveness of digital tools in identifying symptomatic individuals, ensuring appropriate isolation, and testing to disrupt transmission; and impact on public health staff efficiency and program costs.

Efavirenz Pharmacokinetics and Human Immunodeficiency Virus Type 1 (HIV-1) Viral Suppression Among Patients Receiving Tuberculosis Treatment Containing Daily High-Dose Rifapentine.

BACKGROUND: A 4-month regimen containing rifapentine and moxifloxacin has noninferior efficacy compared to the standard 6-month regimen for drug-sensitive tuberculosis. We evaluated the effect of regimens containing daily, high-dose rifapentine on efavirenz pharmacokinetics and viral suppression in patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB). METHODS: In the context of a Phase 3 randomized controlled trial, HIV-positive individuals already virally suppressed on efavirenz--containing antiretroviral therapy (ART) (EFV1), or newly initiating efavirenz (EFV2) received TB treatment containing rifapentine (1200 mg), isoniazid, pyrazinamide, and either ethambutol or moxifloxacin. Mid-interval efavirenz concentrations were measured (a) during ART and TB cotreatment (Weeks 4, 8, 12, and 17, different by EFV group) and (b) when ART was taken alone (pre- or post-TB treatment, Weeks 0 and 22). Apparent oral clearance (CL/F) was estimated and compared. Target mid-interval efavirenz concentrations were > 1 mg/L. Co-treatment was considered acceptable if > 80% of participants had mid-interval efavirenz concentrations meeting this target. RESULTS: EFV1 and EFV2 included 70 and 41 evaluable participants, respectively. The geometric mean ratio comparing efavirenz CL/F with vs without TB drugs was 0.79 (90% confidence interval [CI] .72-.85) in EFV1 and 0.84 [90% CI .69-.97] in EFV2. The percent of participants with mid-interval efavirenz concentrations > 1mg/L in EFV1 at Weeks 0, 4, 8, and 17 was 96%, 96%, 88%, and 89%, respectively. In EFV2, at approximately 4 and 8 weeks post efavirenz initiation, the value was 98%. CONCLUSIONS: TB treatment containing high-dose daily rifapentine modestly decreased (rather than increased) efavirenz clearance and therapeutic targets were met supporting the use of efavirenz with these regimens, without dose adjustment. CLINICAL TRIALS REGISTRATION: NCT02410772.

Four-Month Rifapentine Regimens with or without Moxifloxacin for Tuberculosis.

BACKGROUND: Rifapentine-based regimens have potent antimycobacterial activity that may allow for a shorter course in patients with drug-susceptible pulmonary tuberculosis. METHODS: In an open-label, phase 3, randomized, controlled trial involving persons with newly diagnosed pulmonary tuberculosis from 13 countries, we compared two 4-month rifapentine-based regimens with a standard 6-month regimen consisting of rifampin, isoniazid, pyrazinamide, and ethambutol (control) using a noninferiority margin of 6.6 percentage points. In one 4-month regimen, rifampin was replaced with rifapentine; in the other, rifampin was replaced with rifapentine and ethambutol with moxifloxacin. The primary efficacy outcome was survival free of tuberculosis at 12 months. RESULTS: Among 2516 participants who had undergone randomization, 2343 had a culture positive for Mycobacterium tuberculosis that was not resistant to isoniazid, rifampin, or fluoroquinolones (microbiologically eligible population; 768 in the control group, 791 in the rifapentine-moxifloxacin group, and 784 in the rifapentine group), of whom 194 were coinfected with human immunodeficiency virus and 1703 had cavitation on chest radiography. A total of 2234 participants could be assessed for the primary outcome (assessable population; 726 in the control group, 756 in the rifapentine-moxifloxacin group, and 752 in the rifapentine group). Rifapentine with moxifloxacin was noninferior to the control in the microbiologically eligible population (15.5% vs. 14.6% had an unfavorable outcome; difference, 1.0 percentage point; 95% confidence interval [CI], -2.6 to 4.5) and in the assessable population (11.6% vs. 9.6%; difference, 2.0 percentage points; 95% CI, -1.1 to 5.1). Noninferiority was shown in the secondary and sensitivity analyses. Rifapentine without moxifloxacin was not shown to be noninferior to the control in either population (17.7% vs. 14.6% with an unfavorable outcome in the microbiologically eligible population; difference, 3.0 percentage points [95% CI, -0.6 to 6.6]; and 14.2% vs. 9.6% in the assessable population; difference, 4.4 percentage points [95% CI, 1.2 to 7.7]). Adverse events of grade 3 or higher occurred during the on-treatment period in 19.3% of participants in the control group, 18.8% in the rifapentine-moxifloxacin group, and 14.3% in the rifapentine group. CONCLUSIONS: The efficacy of a 4-month rifapentine-based regimen containing moxifloxacin was noninferior to the standard 6-month regimen in the treatment of tuberculosis. (Funded by the Centers for Disease Control and Prevention and others; Study 31/A5349 ClinicalTrials.gov number, NCT02410772.).

Optimizing drug inventory management with a web-based information system: The TBTC Study 31/ACTG A5349 experience.

INTRODUCTION: Efficient management of study drug inventory shipments is critical to keep research sites enrolling into multisite clinical treatment trials. A standard manual drug-management process used by the Tuberculosis Trials Consortium (TBTC), did not accommodate import permit approval timelines, shipment transit-times and time-zone differences. We compared a new web-based solution with the manual process, during an international 34-site clinical trial conducted by the TBTC and the AIDS Clinical Trials Group (ACTG); TBTC Study 31/ACTG A5349. MATERIAL AND METHODS: We developed and implemented a technological solution by integrating logistical and regulatory requirements for drug importation with statistical simulations that estimated stock-out times in an online Drug Management Module (DMM). We measured the average shipment-related drug stock-outs and time to drug availability, to assess the efficiency of the DMM compared to the manual approach. RESULTS: An Interrupted Time-Series (ITS) analysis showed a 15.4% [p-value = 0.03; 95% C.I. (-28.8%, -2.0%)] reduction in average shipment-related study drug stock-out after DMM implementation. The DMM streamlined the restocking process at study sites, reducing median transit-time for sites associated with a depot by 2 days [95% C.I. (-3.0, -1.0)]. Under the DMM, study drugs were available for treatment assignment on the day received, compared to one day after receipt under the manual process. DISCUSSION: The DMM provided TBTC's Data and Coordinating Center and site staff with more efficient procedures to manage and consistently maintain study drug inventory at enrolling sites. This DMM framework can improve efficiency in future multicenter clinical trials. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov (Identifier: NCT02410772) on April 8, 2015.

Central monitoring in a randomized, open-label, controlled phase 3 clinical trial for a treatment-shortening regimen for pulmonary tuberculosis.

INTRODUCTION: With the growing use of online study management systems and rapid availability of data, timely data review and quality assessments are necessary to ensure proper clinical trial implementation. In this report we describe central monitoring used to ensure protocol compliance and accurate data reporting, implemented during a large phase 3 clinical trial. MATERIAL AND METHODS: The Tuberculosis Trials Consortium (TBTC) Study 31/AIDS Clinical Trials Group (ACTG) study A5349 (S31) is an international, multi-site, randomized, open-label, controlled, non-inferiority phase 3 clinical trial comparing two 4-month regimens to a standard 6 month regimen for treatment of drug-susceptible tuberculosis (TB) among adolescents and adults with a sample size of 2500 participants. RESULTS: Central monitoring utilized primary study data in a five-tiered approach, including (1) real-time data checks & topic-specific intervention reports, (2) missing forms reports, (3) quality assurance metrics, (4) critical data reports and (5) protocol deviation identification, aimed to detect and resolve quality challenges. Over the course of the study, 240 data checks and reports were programed across the five tiers used. DISCUSSION: This use of primary study data to identify issues rapidly allowed the study sponsor to focus quality assurance and data cleaning activities on prioritized data, related to protocol compliance and accurate reporting of study results. Our approach enabled us to become more efficient and effective as we informed sites about deviations, resolved missing or inconsistent data, provided targeted guidance, and gained a deeper understanding of challenges experienced at clinical trial sites. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov (Identifier: NCT02410772) on April 8, 2015.

Optimising pyrazinamide for the treatment of tuberculosis.

Pyrazinamide is a potent sterilising agent that shortens the treatment duration needed to cure tuberculosis. It is synergistic with novel and existing drugs for tuberculosis. The dose of pyrazinamide that optimises efficacy while remaining safe is uncertain, as is its potential role in shortening treatment duration further.Pharmacokinetic data, sputum culture, and safety laboratory results were compiled from Tuberculosis Trials Consortium (TBTC) studies 27 and 28 and Pan-African Consortium for the Evaluation of Antituberculosis Antibiotics (PanACEA) multi-arm multi-stage tuberculosis (MAMS-TB), multi-centre phase 2 trials in which participants received rifampicin (range 10-35 mg·kg-1), pyrazinamide (range 20-30 mg·kg-1), plus two companion drugs. Pyrazinamide pharmacokinetic-pharmacodynamic (PK-PD) and pharmacokinetic-toxicity analyses were performed.In TBTC studies (n=77), higher pyrazinamide maximum concentration (Cmax) was associated with shorter time to culture conversion (TTCC) and higher probability of 2-month culture conversion (p-value<0.001). Parametric survival analyses showed that relationships varied geographically, with steeper PK-PD relationships seen among non-African than African participants. In PanACEA MAMS-TB (n=363), TTCC decreased as pyrazinamide Cmax increased and varied by rifampicin area under the curve (p-value<0.01). Modelling and simulation suggested that very high doses of pyrazinamide (>4500 mg) or increasing both pyrazinamide and rifampicin would be required to reach targets associated with treatment shortening. Combining all trials, liver toxicity was rare (3.9% with grade 3 or higher liver function tests (LFT)), and no relationship was seen between pyrazinamide Cmax and LFT levels.Pyrazinamide's microbiological efficacy increases with increasing drug concentrations. Optimising pyrazinamide alone, though, is unlikely to be sufficient to allow tuberculosis treatment shortening; rather, rifampicin dose would need to be increased in parallel.

Decreased plasma rifapentine concentrations associated with AADAC single nucleotide polymorphism in adults with tuberculosis.

BACKGROUND: Rifapentine exposure is associated with bactericidal activity against Mycobacterium tuberculosis, but high interindividual variation in plasma concentrations is encountered. OBJECTIVES: To investigate a genomic association with interindividual variation of rifapentine exposure, SNPs of six human genes involving rifamycin metabolism (AADAC, CES2), drug transport (SLCO1B1, SLCO1B3) and gene regulation (HNF4A, PXR) were evaluated. METHODS: We characterized these genes in 173 adult participants in treatment trials of the Tuberculosis Trials Consortium. Participants were stratified by self-identified race (black or non-black), and rifapentine AUC from 0 to 24 h (AUC0-24) was adjusted by analysis of covariance for SNPs, rifapentine dose, sex, food and HIV coinfection. This study was registered at ClinicalTrials.gov under identifier NCT01043575. RESULTS: The effect on rifapentine least squares mean AUC0-24 in black participants overall decreased by -10.2% for AADAC rs1803155 G versus A allele (Wald test: P = 0.03; false discovery rate, 0.10). Black participants with one G allele in AADAC rs1803155 were three times as likely to have below target bactericidal rifapentine exposure than black participants with the A allele (OR, 2.97; 95% CI: 1.16, 7.58). With two G alleles, the OR was greater. In non-black participants, AADAC rs1803155 SNP was not associated with rifapentine exposure. In both black and non-black participants, other evaluated genes were not associated with rifapentine exposure (P > 0.05; false discovery rate > 0.10). CONCLUSIONS: Rifapentine exposure in black participants varied with AADAC rs1803155 genotype and the G allele was more likely to be associated with below bactericidal target rifapentine exposure. Further pharmacogenomic study is needed to characterize the association of the AADAC rs1803155 with inadequate rifapentine exposure in different patient groups.

High-dose rifapentine with or without moxifloxacin for shortening treatment of pulmonary tuberculosis: Study protocol for TBTC study 31/ACTG A5349 phase 3 clinical trial.

INTRODUCTION: Phase 2 clinical trials of tuberculosis treatment have shown that once-daily regimens in which rifampin is replaced by high dose rifapentine have potent antimicrobial activity that may be sufficient to shorten overall treatment duration. Herein we describe the design of an ongoing phase 3 clinical trial testing the hypothesis that once-daily regimens containing high dose rifapentine in combination with other anti-tuberculosis drugs administered for four months can achieve cure rates not worse than the conventional six-month treatment regimen. METHODS/DESIGN: S31/A5349 is a multicenter randomized controlled phase 3 non-inferiority trial that compares two four-month regimens with the standard six-month regimen for treating drug-susceptible pulmonary tuberculosis in HIV-negative and HIV-positive patients. Both of the four-month regimens contain high-dose rifapentine instead of rifampin, with ethambutol replaced by moxifloxacin in one regimen. All drugs are administered seven days per week, and under direct observation at least five days per week. The primary outcome is tuberculosis disease-free survival at twelve months after study treatment assignment. A total of 2500 participants will be randomized; this gives 90% power to show non-inferiority with a 6.6% margin of non-inferiority. DISCUSSION: This phase 3 trial formally tests the hypothesis that augmentation of rifamycin exposures can shorten tuberculosis treatment to four months. Trial design and standardized implementation optimize the likelihood of obtaining valid results. Results of this trial may have important implications for clinical management of tuberculosis at both individual and programmatic levels. TRIAL REGISTRATION: NCT02410772. Registered 8 April 2015,https://www.clinicaltrials.gov/ct2/show/NCT02410772?term=02410772&rank=1.

Bacterial Factors That Predict Relapse after Tuberculosis Therapy.

BACKGROUND: Approximately 5% of patients with drug-susceptible tuberculosis have a relapse after 6 months of first-line therapy, as do approximately 20% of patients after 4 months of short-course therapy. We postulated that by analyzing pretreatment isolates of Mycobacterium tuberculosis obtained from patients who subsequently had a relapse or were cured, we could determine any correlations between the minimum inhibitory concentration (MIC) of a drug below the standard resistance breakpoint and the relapse risk after treatment. METHODS: Using data from the Tuberculosis Trials Consortium Study 22 (development cohort), we assessed relapse and cure isolates to determine the MIC values of isoniazid and rifampin that were below the standard resistance breakpoint (0.1 µg per milliliter for isoniazid and 1.0 µg per milliliter for rifampin). We combined this analysis with clinical, radiologic, and laboratory data to generate predictive relapse models, which we validated by analyzing data from the DMID 01-009 study (validation cohort). RESULTS: In the development cohort, the mean (±SD) MIC of isoniazid below the breakpoint was 0.0334±0.0085 µg per milliliter in the relapse group and 0.0286±0.0092 µg per milliliter in the cure group, which represented a higher value in the relapse group by a factor of 1.17 (P=0.02). The corresponding MIC values of rifampin were 0.0695±0.0276 and 0.0453±0.0223 µg per milliliter, respectively, which represented a higher value in the relapse group by a factor of 1.53 (P<0.001). Higher MIC values remained associated with relapse in a multivariable analysis that included other significant between-group differences. In an analysis of receiver-operating-characteristic curves of relapse based on these MIC values, the area under the curve (AUC) was 0.779. In the development cohort, the AUC in a multivariable model that included MIC values was 0.875. In the validation cohort, the MIC values either alone or combined with other patient characteristics were also predictive of relapse, with AUC values of 0.964 and 0.929, respectively. The use of a model score for the MIC values of isoniazid and rifampin to achieve 75.0% sensitivity in cross-validation analysis predicted relapse with a specificity of 76.5% in the development cohort and a sensitivity of 70.0% and a specificity of 100% in the validation cohort. CONCLUSIONS: In pretreatment isolates of M. tuberculosis with decrements of MIC values of isoniazid or rifampin below standard resistance breakpoints, higher MIC values were associated with a greater risk of relapse than lower MIC values. (Funded by the National Institute of Allergy and Infectious Diseases.).

Elevated Plasma Moxifloxacin Concentrations and SLCO1B1 g.-11187G>A Polymorphism in Adults with Pulmonary Tuberculosis.

Moxifloxacin exhibits concentration-dependent prolongation of human QTc intervals and bactericidal activity against Mycobacterium tuberculosis However, moxifloxacin plasma concentrations are variable between patients. We evaluated whether human gene polymorphisms affect moxifloxacin plasma concentrations in tuberculosis patients from two geographic regions. We enrolled a convenience sample of 49 adults with drug-sensitive pulmonary tuberculosis from Africa and the United States enrolled in two treatment trials of moxifloxacin as part of multidrug therapy. Pharmacokinetic parameters were evaluated by noncompartmental techniques. Human single-nucleotide polymorphisms of transporter genes were evaluated by analysis of covariance (ANCOVA) on moxifloxacin exposure and the peak (maximum) concentration (Cmax). The moxifloxacin area under the concentration-time curve from 0 to 24 h (AUC0-24) and Cmax were significantly increased by the drug milligram-per-kilogram dosage and the genotype of variant g.-11187G>A in the SLCO1B1 gene (rs4149015) but not by geographic region. The median moxifloxacin AUC0-24 was 46% higher and the median Cmax was 30% higher in 4 (8%) participants who had the SLCO1B1 g.-11187 AG genotype than in 45 participants who had the wild-type GG genotype (median AUC0-24 from the model, 34.4 versus 23.6 µg · h/ml [P = 0.005, ANCOVA]; median Cmax from the model, 3.5 versus 2.7 µg/ml [P = 0.009, ANCOVA]). Because moxifloxacin exhibits concentration-dependent prolongation of human QTc intervals and prolonged QTc intervals are associated with cardiac arrhythmia, further study is needed to evaluate the risk associated with the SLCO1B1 g.-11187G>A variant. (This study has been registered at ClinicalTrials.gov under identifier NCT00164463.).

HIV Testing and HIV Service Delivery to Populations at High Risk Attending Sexually Transmitted Disease Clinics in the United States, 2011-2013.

OBJECTIVES: We evaluated HIV testing and service delivery in Centers for Disease Control and Prevention (CDC)-funded sexually transmitted disease (STD) clinics. METHODS: We assessed HIV testing, HIV positivity, receipt of HIV test results, linkage to medical care, and referral services from 61 health department jurisdictions from 2011 to 2013. RESULTS: In 2013, 18.6% (621 010) of all CDC-funded HIV-testing events were conducted in STD clinics, and 0.8% were newly identified as HIV-positive. In addition, 27.3% of all newly identified HIV-positive persons and 30.1% of all newly identified HIV-positive men who have sex with men were identified in STD clinics. Linkage to care within any time frame was 63.8%, and linkage within 90 days was 55.3%. Although there was a decrease in first-time HIV testers in STD clinics from 2011 to 2013, identification of new positives increased. CONCLUSIONS: Although linkage to care and referral to partner services could be improved, STD clinics appear successful at serving populations disproportionately affected by HIV. These clinics may reach persons who may not otherwise seek HIV testing or medical services and provide an avenue for service provision to these populations.

Quantification of rifapentine, a potent antituberculosis drug, from dried blood spot samples using liquid chromatographic-tandem mass spectrometric analysis.

The quantification of antituberculosis drug concentrations in multinational trials currently requires the collection of modest blood volumes, centrifugation, aliquoting of plasma, freezing, and keeping samples frozen during shipping. We prospectively enrolled healthy individuals into the Tuberculosis Trials Consortium Study 29B, a phase I dose escalation study of rifapentine, a rifamycin under evaluation in tuberculosis treatment trials. We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying rifapentine in whole blood on dried blood spots (DBS) to facilitate pharmacokinetic/pharmacodynamic analyses in clinical trials. Paired plasma and whole-blood samples were collected by venipuncture, and whole blood was spotted on Whatman protein saver 903 cards. The methods were optimized for plasma and then validated for DBS. The analytical measuring range for quantification of rifapentine and its metabolite was 50 to 80,000 ng/ml in whole-blood DBS. The analyte was stable on the cards for 11 weeks with a desiccant at room temperature and protected from light. The method concordance for paired plasma and whole-blood DBS samples was determined after correcting for participant hematocrit or population-based estimates of bias from Bland-Altman plots. The application of either correction factor resulted in acceptable correlation between plasma and whole-blood DBS (Passing-Bablok regression corrected for hematocrit; y = 0.98x + 356). Concentrations of rifapentine may be determined from whole-blood DBS collected via venipuncture after normalization in order to account for the dilutional effects of red blood cells. Additional studies are focused on the application of this methodology to capillary blood collected by finger stick. The simplicity of processing, storage, shipping, and low blood volume makes whole-blood DBS attractive for rifapentine pharmacokinetic evaluations, especially in international and pediatric trials.

Aptamer-based proteomic signature of intensive phase treatment response in pulmonary tuberculosis.

BACKGROUND: New drug regimens of greater efficacy and shorter duration are needed for tuberculosis (TB) treatment. The identification of accurate, quantitative, non-culture based markers of treatment response would improve the efficiency of Phase 2 TB drug testing. METHODS: In an unbiased biomarker discovery approach, we applied a highly multiplexed, aptamer-based, proteomic technology to analyze serum samples collected at baseline and after 8 weeks of treatment from 39 patients with pulmonary TB from Kampala, Uganda enrolled in a Centers for Disease Control and Prevention (CDC) TB Trials Consortium Phase 2B treatment trial. RESULTS: We identified protein expression differences associated with 8-week culture status, including Coagulation Factor V, SAA, XPNPEP1, PSME1, IL-11 Rα, HSP70, Galectin-8, α2-Antiplasmin, ECM1, YES, IGFBP-1, CATZ, BGN, LYNB, and IL-7. Markers noted to have differential changes between responders and slow-responders included nectin-like protein 2, EphA1 (Ephrin type-A receptor 1), gp130, CNDP1, TGF-b RIII, MRC2, ADAM9, and CDON. A logistic regression model combining markers associated with 8-week culture status revealed an ROC curve with AUC = 0.96, sensitivity = 0.95 and specificity = 0.90. Additional markers showed differential changes between responders and slow-responders (nectin-like protein), or correlated with time-to-culture-conversion (KLRK1). CONCLUSIONS: Serum proteins involved in the coagulation cascade, neutrophil activity, immunity, inflammation, and tissue remodeling were found to be associated with TB treatment response. A quantitative, non-culture based, five-marker signature predictive of 8-week culture status was identified in this pilot study.

Population pharmacokinetics of rifapentine and desacetyl rifapentine in healthy volunteers: nonlinearities in clearance and bioavailability.

Rifapentine is under active investigation as a potent drug that may help shorten the tuberculosis (TB) treatment duration. A previous rifapentine dose escalation study with daily dosing indicated a possible decrease in bioavailability as the dose increased and an increase in clearance over time for rifapentine and its active metabolite, desacetyl rifapentine. This study aimed to assess the effects of increasing doses on rifapentine absorption and bioavailability and to evaluate the clearance changes over 14 days. A population analysis was performed with nonlinear mixed-effects modeling. Absorption, time-varying clearance, bioavailability, and empirical and semimechanistic autoinduction models were investigated. A one-compartment model linked to a transit compartment absorption model best described the data. The bioavailability of rifapentine decreased linearly by 2.5% for each 100-mg increase in dose. The autoinduction model suggested a dose-independent linear increase in clearance of the parent drug and metabolite over time from 1.2 and 3.1 liters · h(-1), respectively, after a single dose to 2.2 and 5.0 liters · h(-1), respectively, after 14 once-daily doses, with no plateau being reached by day 14. In clinical trial simulations using the final model, rifapentine demonstrated less-than-dose-proportional pharmacokinetics, but there was no plateau in exposures over the dose range tested (450 to 1,800 mg), and divided dosing increased exposures significantly. Thus, the proposed compartmental model incorporating daily dosing of rifapentine over a wide range of doses and time-related changes in bioavailability and clearance provides a useful tool for estimation of drug exposure that can be used to optimize rifapentine dosing for TB treatment. (This study has been registered at ClinicalTrials.gov under registration no. NCT01162486.).