Fit-for-Purpose Biometric Monitoring Technologies: Leveraging the Laboratory Biomarker Experience

Biometric monitoring technologies (BioMeTs) are becoming increasingly common to aid data collection in clinical trials and practice. The state of BioMeTs, and associated digitally measured biomarkers, is highly reminiscent of the field of laboratory biomarkers 2 decades ago. In this review, we have summarized and leveraged historical perspectives, and lessons learned from laboratory biomarkers as they apply to BioMeTs. Both categories share common features, including goals and roles in biomedical research, definitions, and many elements of the biomarker qualification framework. They can also be classified based on the underlying technology, each with distinct features and performance characteristics, which require bench and human experimentation testing phases. In contrast to laboratory biomarkers, digitally measured biomarkers require prospective data collection for purposes of analytical validation in human subjects, lack well‐established and widely accepted performance characteristics, require human factor testing, and, for many applications, access to raw (sample‐level) data. Novel methods to handle large volumes of data, as well as security and data rights requirements add to the complexity of this emerging field. Our review highlights the need for a common framework with appropriate vocabulary and standardized approaches to evaluate digitally measured biomarkers, including defining performance characteristics and acceptance criteria. Additionally, the need for human factor testing drives early patient engagement during technology development. Finally, use of BioMeTs requires a relatively high degree of technology literacy among both study participants and healthcare professionals. Transparency of data generation and the need for novel analytical and statistical tools creates opportunities for precompetitive collaborations.

Relative Bioavailability of Liquid and Tablet Formulations of the Antiparasitic Moxidectin

The antiparasitic agent moxidectin is under development for the treatment of onchocerciasis. As the first-in-human study of moxidectin used a liquid formulation but other trials used tablets, a study was performed to determine the relative bioavailability of the 2 formulations and to gain more information about the pharmacokinetics of moxidectin. Fifty-eight healthy male participants were randomized to receive open-label moxidectin (10 mg) as a tablet (n = 29) or liquid (n = 29) formulation. The mean ± SD pharmacokinetic parameters observed following administration of the tablet were peak concentration (Cmax) 67.1 ± 27.4 ng/mL, time to peak concentration (tmax) 3.2 ± 1.4 hours, area under the concentration time curve (AUC) 4403 ± 2360 ng·h/mL, apparent volume of distribution 3635 ± 1720 L, oral clearance 2.83 ± 1.25 L/h, and elimination half-life 1032 ± 502 hours. The Cmax and AUC observed following administration of the liquid formulation were 28.6% and 28.8% higher, respectively, and tmax 0.9 hours shorter compared with tablets. No serious adverse events (AEs) were observed. The most commonly reported AEs were headache, infection, diarrhea, asthenia, myalgia, and dizziness during the inpatient phase and flu syndrome, headache, and infection during the 6-month outpatient phase. There was no difference in reporting of these AEs between formulations.

Effect of moxidectin on CYP3A4 activity as evaluated by oral midazolam pharmacokinetics in healthy subjects

In order to evaluate the potential for CYP3A4 induction by moxidectin, midazolam pharmacokinetic (PK) parameters were compared before and after moxidectin administration. Healthy subjects received a single 8 mg dose of moxidectin and 3 single 7.5 mg doses of midazolam 3 days before, and 7 and 89 days after the moxidectin. Blood samples were taken for 24 hours to measure midazolam and metabolites in plasma, and for 89 days to measure moxidectin in plasma after dose administration. Noncompartmental PK analyses were performed for each analyte. Analysis of variance was performed on log-transformed midazolam parameters with treatment day as a fixed effect. Adverse events were recorded and laboratory tests, physical examinations, pulse oximetry monitoring, vital sign measurement, and electrocardiograms performed. Thirty-nine subjects were enrolled in the study; PK data were available for 37 subjects. Moxidectin PK parameters were similar to previous studies. There were no significant changes in PK for midazolam or its metabolites 7 or 89 days after moxidectin administration. Adverse events were generally mild and there were no relevant changes in safety assessments. Thus, 8 mg moxidectin does not induce CYP3A4 activity and other CYP3A4 substrates are unlikely to be affected by moxidectin co-administration.

Absence of a Pharmacokinetic Interaction between Etanercept and Warfarin

Etanercept, a soluble recombinant human tumor necrosis factor receptor (TNFr) fusion protein, is effective and well tolerated in the treatment of rheumatoid arthritis (RA), juvenile rheumatoid arthritis (JRA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS). The primary objective of this study was to investigate the potential pharmacokinetic and pharmacodynamic interaction between a single dose of R- and S-enantiomers of warfarin and multiple doses of etanercept after administration of warfarin and etanercept alone and together. In a nonrandomized, three-period study, 12 healthy male subjects received a single oral 25-mg dose of warfarin after an overnight fast, followed by twice-weekly 25-mg subcutaneous doses of etanercept for seven doses. The last dose of etanercept was administered concurrently with a second dose of warfarin. Serial blood samples for plasma warfarin concentration measurement and international normalized ratio (INR) assessment were collected before and up to 144 hours after dose administration. Serial blood samples for serum etanercept concentration measurement were collected before and up to 60 hours after the sixth dose and 264 hours after the seventh dose. Etanercept did not affect the pharmacokinetics and pharmacodynamics of warfarin. All ratios of maximum serum concentration (C(max)) and area under the serum concentration versus time curve (AUC) for pharmacokinetics (R- and S-enantiomers of warfarin) and INR fell within the confidence interval of 0.8 to 1.25. Warfarin also did not cause a clinically significant alteration in the pharmacokinetics of etanercept. In conclusion, coadministration of etanercept and warfarin would not be expected to change the pharmacokinetics of either medication; therefore, no dosage adjustment is needed in cases in which warfarin and etanercept are coadministered.

Concomitant blockade of 5-HT(1A) receptor and 5-HT transporter: use of the Hunter Serotonin toxicity criteria in a clinical pharmacology study

There is a potential risk that 5-HT(1A) receptor blockade combined with blockade of the 5-HT transporter by an SSRI may cause a toxic increase in 5-HT within the synapse, sparking concern for 'serotonin syndrome', a rare but potentially life threatening condition. We evaluated the safety and pharmacodynamics of the combination of the 5-HT(1A) antagonist lecozotan and the SSRI citalopram in a well-controlled Clinical Pharmacology Unit setting using the Hunter Serotonin Toxicity Criteria (HSTC), a set of validated decision rules featuring neurological and body temperature measurements, to detect any clinically relevant serotonin toxicity. Forty-three young healthy male subjects were randomized, to 2 parallel double-blind treatment groups following a 10-day citalopram 40 mg run-in period: citalopram 40 mg/lecozotan 10mg or citalopram 40 mg/placebo for 9 days. Overall, the combined administration of active drugs was well tolerated, however, one subject experienced moderate hyperreflexia, tremor of the hands, and sweating of hands and feet after 3 days of combined treatment. The event prompted treatment withdrawal and was regarded as mild serotonin toxicity, as per the HSTC. The onset of the event was around the time of peak plasma concentrations (t(max)) of both lecozotan and citalopram, and its time course corresponds to the well-defined PK profile of lecozotan. No evidence of a PK interaction was detected trough lecozotan and citalopram plasma concentrations analysis. The utility of the HSTC in detecting the non-discrete group of symptoms commonly referred to as "serotonin toxicity" was demonstrated in this clinical pharmacology study combining two 5-HT agents in a clinically controlled setting.

The effect of a high-fat breakfast on the pharmacokinetics of moxidectin in healthy male subjects: a randomized phase I trial

The objective of this study was to assess the effect of a high-fat meal on the pharmacokinetics of moxidectin. Healthy male subjects were randomized to receive single oral 8 mg doses of moxidectin after an overnight fast or high-fat breakfast. In fasted subjects (N = 27), mean [SD] parameters were C(max): 58.9 [12.5] ng/mL; t(max): 3.7 [1.5] h; area under concentration-time curve (AUC): 3,387 [1,328] ng/h/mL; Vλ(z)/F: 2,829 [1,267] L; CL/F: 2.76 [1.28] L/h; and t(1/2): 784 [347] h. Compared with fasted subjects, fed subjects (N = 27) exhibited a 34% increase in C(max), delay in t(max) to 5.3 [2.1] h, 44% increase in AUC, 40% decrease in Vλ(z)/F, and a 35% decrease in CL/F. There was no significant change in t(1/2). The changes are consistent with an increase in moxidectin bioavailability following administration with food. There were no clinically relevant changes in vital signs, laboratory tests, or electrocardiograms.

Safety, tolerability, pharmacokinetics and pharmacodynamics of ascending single and multiple doses of lecozotan in healthy young and elderly subjects

AIMS

To determine the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of oral immediate release (IR) lecozotan in healthy young and elderly subjects.

METHODS

Three randomized, double-blind, placebo-controlled, sequential, ascending dose Phase I studies of lecozotan were conducted. In a single-dose study, ascending doses of 2, 5 and 10 mg were administered to cohorts of eight young subjects. In the two ascending 14-day multiple-dose studies, 41 young subjects received 0.1, 0.25, 0.5, 1 and 5 mg q12h of lecozotan or placebo and 24 elderly received 0.5 mg and 5 mg q12h of lecozotan or placebo. Assessments included safety evaluations, a complete PK profile and PD.

RESULTS

Lecozotan was safe and well tolerated at steady state up to 5 mg q12. The maximum tolerated dose after multiple doses was >10 mg (5 mg q12). In the single-dose study, the maximum tolerated dose was 10 mg. Dose-limiting mild-to-moderate adverse events included paraesthesia, dizziness and visual disturbances peaking at t(max) and disappearing concomitantly with plasma concentrations. No clinically relevant changes in vital signs, ECG intervals or routine laboratory tests occurred. Lecozotan did not significantly change cognitive function, EEG or hormone levels. PK was characterized by rapid absorption, dose proportionality, extensive distribution and rapid elimination. The mean CL/F was approximately 35% lower in the elderly.

CONCLUSIONS

Lecozotan IR was safe and well tolerated after administration of multiple oral doses up to 5 mg q12h in young and elderly subjects. These results support the development of lecozotan in patients with Alzheimer's disease.

Pharmacokinetics of sirolimus (rapamycin) in subjects with severe hepatic impairment

Nine subjects with severe hepatic impairment (Child-Pugh grade C) and 9 healthy matched control subjects were given a single 15-mg dose of sirolimus by oral solution. Increases (P < or = .002) in mean whole-blood sirolimus t(1/2) (168%), AUC(0-infinity) (210%), and MRT(oral) (261%), together with a decrease (P = .001) in CL/F (-67%), were observed in subjects with severe hepatic impairment compared with healthy matched controls. Sirolimus pharmacokinetic data in Child-Pugh grade A (n = 13, mild) and B (n = 5, moderate) subjects from a previous identically designed study were available for an inter-study comparison. Overall, mean t(1/2), weight-normalized AUC, and MRT(oral) increased steadily, whereas mean CL/F decreased steadily, with increasing degrees of hepatic impairment. CL/F showed large intersubject variabilities within subject types and extensive overlap among the subject types. The results of this study suggest that an initial sirolimus dose reduction of approximately 60% is appropriate in patients with acute severe hepatic impairment; this should be followed by further dose adjustment, based on therapeutic drug monitoring, until the trough concentrations have stabilized at sirolimus levels existing prior to the onset of acute liver failure.

A Positron Emission Tomography Study to Assess Binding of Lecozotan, a Novel 5-Hydroxytryptamine-1A Silent Antagonist, to Brain 5-HT1A Receptors in Healthy Young and Elderly Subjects, and in Patients With Alzheimer's Disease

This positron emission tomography (PET) study was conducted to assess binding of lecozotan, a new potent and silent 5-hydroxytryptamine-1A (5-HT1A) antagonist being developed for the treatment of Alzheimer's disease (AD), to 5-HT1A receptors in the human brain using 11C-labeled WAY-100635. Lecozotan was administered as a single dose of 0.5, 1, or 5 mg to young subjects and 5 mg to elderly subjects and AD patients. PET measurements were performed at 3-4 time points over a 25-h period. Mean peak 5-HT1A receptor occupancy (RO) in young subjects (seen at 1 h) was 10%, 18%, and 44% for the three doses, respectively. Mean peak RO was slightly higher in elderly (63%) and AD patients (55%). An Emax pharmacokinetic/pharmacodynamic model adequately described the lecozotan plasma concentration-RO relationship. Steady-state peak RO is predicted to be approximately 70% for 5 mg q12 h (twice-daily). Results demonstrate that lecozotan binds to the human brain 5-HT1A receptors and has a maximum observed RO of 50-60% following a single dose of 5 mg in elderly subjects/AD patients.

Absence of a clinically relevant interaction between etanercept and digoxin

Etanercept, a soluble recombinant human tumor necrosis factor receptor (TNFr), is effective and well tolerated in the treatment of rheumatoid arthritis, juvenile rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and psoriasis. The primary objective of this study was to investigate the potential pharmacokinetic and pharmacodynamic interaction between digoxin and etanercept at steady state. In a crossover, open-label, nonrandomized, 3-period study, 12 healthy male subjects received loading oral doses of digoxin 0.5 mg every 12 hours on day 1 and 0.25 mg every 12 hours on day 2, followed by a daily maintenance dose of 0.25 mg for a total of 27 days. Etanercept was administered as a twice-weekly 25-mg subcutaneous dose beginning on day 9 and continuing up to day 37 for a total of 9 doses. All ratios of maximum plasma concentration (C(max)) and area under the plasma concentration versus time curve (AUC) for pharmacokinetics of digoxin fell within the confidence interval of 0.8 to 1.25. Although not considered clinically relevant, the mean C(max) and AUC of etanercept were 4.2% and 12.5% lower, respectively, when etanercept was given with digoxin than when administered alone. There were no clinically relevant changes in the electrocardiogram (ECG) parameters, and adverse events did not increase when both drugs were combined. In conclusion, there is no clinically relevant interaction between etanercept and digoxin, and both drugs can be safely coadministered without the need for a dosage adjustment.

Lack of pharmacokinetic interaction between retigabine and phenobarbitone at steady-state in healthy subjects

AIMS

To evaluate potential pharmacokinetic interactions between phenobarbitone and retigabine, a new antiepileptic drug.

METHODS

Fifteen healthy men received 200 mg of retigabine on day 1. On days 4-32, phenobarbitone 90 mg was administered at 22.00 h. On days 26-32, increasing doses of retigabine were given to achieve a final dose of 200 mg every 8 h on day 32. The pharmacokinetics of retigabine were determined on days 1 and 32, and those for phenobarbitone on days 25 and 31.

RESULTS

After administration of a single 200 mg dose, retigabine was rapidly absorbed and eliminated with a mean terminal half-life of 6.7 h, a mean AUC of 3936 ng x ml(-1) x h and a mean apparent clearance of 0.76 l x h(-1) x kg(-1). Similar exposure to the partially active acetylated metabolite (AWD21-360) of retigabine was observed. After administration of phenobarbitone dosed to steady-state, the pharmacokinetics of retigabine at steady-state were similar (AUC of 4433 ng x ml(-1) x h and t1/2 of 8.5 h) to those of retigabine alone. The AUC of phenobarbitone was 298 mg x l(-1) x h when administered alone and 311 mg x ml(-1) x h after retigabine administration. The geometric mean ratios and 90% confidence intervals of the AUC were 1.11 (0.97, 1.28) for retigabine, 1.01 (0.88, 1.06) for AWD21-360 and 1.04 (0.96, 1.11) for phenobarbitone. Individual and combined treatments were generally well tolerated. One subject was withdrawn from the study on day 10 due to severe abdominal pain. Headache was the most commonly reported adverse event. No clinically relevant changes were observed in the electrocardiograms, vital signs or laboratory measurements.

CONCLUSIONS

There was no pharmacokinetic interaction between retigabine and phenobarbitone in healthy subjects. No dosage adjustment is likely to be necessary when retigabine and phenobarbitone are coadministered to patients.

Estimation of neonatal exposure after accidental ingestion of lufenuron in a breastfeeding mother

A case of accidental anti-flea preparation (lufenuron) ingestion by a breastfeeding mother is reported. An estimation of infant exposure level was calculated based on the highest level measured. The breastfed infant was exposed to an average lufenuron dose of 0.032 mg/kg/day, which is only 3% of a reported acute overdose. No adverse effects were reported during 7 months of follow-up. Breastfeeding should be considered cautiously after consultation with a regional poison center in cases of accidental ingestion of this drug by a breastfeeding mother. The infant should be monitored for potential adverse effects.

Perceived stress and coping strategies among candidates for heart transplantation during the organ waiting period

The effectiveness of the transplantation team in diffusing stress during the pretransplantation period is increasingly important the longer the patient remains on the transplant waiting list. This study describes the stressors and coping strategies of heart transplant candidates during the waiting period. Thirty-nine candidates on the active list for heart transplantation from four mid-East Coast transplantation centers participated. With a possible stress score of 0 to 243, the mean score for this sample was a low 72.84 (standard deviation = 37.47). The three most common stressors were (1) requiring a heart transplant, (2) having terminal heart disease, and (3) worrying family members. The three most common coping strategies were (1) thinking positively, (2) using humor, and (3) trying to keep life as normal as possible. The finding of low stress levels was surprising but may reflect the presence of hope or the patient's desire to spare family members worry--a concern commonly cited by patients. Another explanation is that patients desiring to be perceived as ideal transplant recipients may have underreported their stress. This suggests that the transplantation team should support positive coping strategies when possible and that both patient and family coping should be closely monitored throughout the waiting period.

Benefits of an automated narcotic retrieval system

A comparison was made in effectiveness of lock and key and automated narcotics retrieval systems. Time required per narcotic averaged 137 seconds for the traditional mode and 48 seconds for the automated system. This resulted in a monthly savings of $594, along with general nurse satisfaction and a perception of increased security.