PurposeA thorough QT study was conducted to assess the proarrhythmic potential of clobazam and its active metabolite, N-desmethylclobazam (N-CLB). MethodsIn this Phase I, single-site, randomized, double-blind, double-dummy, parallel-group study, healthy participants were randomized to 1 of 4 treatment groups: clobazam 40 mg/d (maximum therapeutic dosage), clobazam 160 mg/d (supratherapeutic dosage), placebo, or moxifloxacin 400 mg (active control). FindingsOf 280 enrolled participants (n = 70 per treatment arm), 250 (92%) completed the study; 194 were included in the pharmacokinetics population (clobazam 40 mg/d, n = 66; clobazam 160 mg/d, n = 62; and moxifloxacin, n = 66). Mean changes from baseline in QT interval placebo-corrected for heart rate using the Fridericia formula (primary end point), Bazett formula, and individual correction method (QTcF, QTcB, and QTcI, respectively) with clobazam 40 and 160 mg/d revealed no effect on QTc. No clinically relevant or treatment-related arrhythmias were observed, and there were no instances of second- or third-degree atrioventricular block. Given that clobazam is primarily demethylated to N-CLB by cytochrome P450 (CYP) enzyme, CYP3A4, the mean plasma time–concentration profile of clobazam was unchanged with the exclusion of CYP2C19 poor metabolizers. As N-CLB is metabolized by CYP2C19, the exclusion of CYP2C19 poor metabolizers resulted in slightly decreased mean plasma time–concentration profiles of N-CLB. Using a linear mixed-effects model, the effects of the clobazam and N-CLB Cmax values on the placebo-corrected changes from baseline in QTcF, QTcI, and QTcB were near zero or slightly negative, and are not considered clinically important. The incidence of treatment-emergent adverse events was greatest in the clobazam groups (number of moderate AEs experienced by patients: PBO, 3/70; MOXI, 5/70; CLB 40 mg/d, 18/70; CLB 160 mg/d, 21/70; severe AEs: PBO, MOXI, & CLB 160 mg/d, 0; CLB 40 mg/d, 2/70); there were no serious AEs in any treatment group. A total of 10% of participants experienced benzodiazepine-withdrawal symptoms (16%, 23%, and 3% in the clobazam 40 and 160 mg/d groups and the moxifloxacin group, respectively). ImplicationsThe findings from this thorough QT study are consistent with existing clinical data and support the lack of proarrhythmic potential with clobazam.

PurposeA thorough QT study was performed to assess the proarrhythmic potential of vigabatrin, an antiepileptic drug approved in the United States for the treatment of infantile spasms and refractory complex partial seizures. MethodsIn this Phase I, randomized, double-blind, placebo- and active-controlled (moxifloxacin), 4-sequence, crossover study conducted at a single center, healthy participants received 1 of 4 randomly assigned treatments: 3.0g vigabatrin solution (therapeutic dose) and 1 moxifloxacin placebo tablet; 6.0g vigabatrin solution (supratherapeutic dose) and 1 moxifloxacin placebo tablet; 400 mg moxifloxacin and vigabatrin placebo solution; moxifloxacin placebo tablet and vigabatrin placebo solution. FindingsMean changes from baseline in placebo-corrected QTcF, QTcB, and QTcI with vigabatrin 3.0 g and 6.0 g indicated no signal for any QTc effect relative to baseline. All 1-sided upper 95% confidence intervals for the differences between each vigabatrin dose and placebo were <10 ms at all time points. QTcF was unaffected by increasing plasma vigabatrin concentrations; no arrhythmias were observed in any treatment group. Low rates of first-degree atrioventricular block, sinus tachycardia, and sinus bradycardia occurred in all treatment groups. Most adverse events were mild. ImplicationsThe findings from this thorough QT study are consistent with existing clinical data and confirm a lack of proarrhythmic potential of vigabatrin.

Drug-induced serotonin syndrome is a potentially life-threatening condition. An Ovid MEDLINE, and PubMed search from 1950 to October 2015 revealed one published case report of suspected tapentadol-induced serotonin syndrome. We report a probable case of tapentadol-induced serotonin syndrome after overdose. A 48-year-old male was found unresponsive after a witnessed overdose of medications including tapentadol. After administration of naloxone by emergency medical services, the patient became combative and presented with altered mental status. He was managed with physical and pharmacologic restraints in the emergency department. Other medications that could be implicated in the patient's presentation include duloxetine and amitriptyline. It was suspected that the opioid properties of tapentadol were masking the patient's signs and symptoms of serotonin syndrome. The patient was admitted to the medical intensive care unit, remained stable, and was discharged 2 days later. Currently, there is one published case report of suspected tapentadol-induced serotonin syndrome after an overdose. The manufacturer of tapentadol reported no cases of serotonin syndrome during clinical trials, but there have been postmarketing cases reported with co-administration of other serotonergic drugs. We report a probable case of tapentadol-induced serotonin syndrome after overdose. Further research is needed to better understand the pharmacology and incidence behind this adverse event.

This single-dose, 4-period crossover study evaluated the pharmacokinetics (PK) of the β2 -agonist indacaterol maleate and the corticosteroid mometasone furoate (MF) after inhalation of a fixed-dose combination (QMF149, indacaterol maleate/MF, 500/400 μg) via the Twisthaler (TH) device with and without activated charcoal and postdose mouth rinsing in healthy volunteers. The PK of indacaterol maleate 300 μg inhaled via the Breezhaler (BRZ) device was also characterized. Relative bioavailability of indacaterol and MF for inhalation with versus without charcoal, based on AUClast, was 0.25 (90% confidence interval [CI], 0.18-0.35) and 0.70 (90%CI, 0.52-0.93), respectively. Thus, 25% and 70% of systemic exposure of indacaterol and MF, respectively was due to pulmonary absorption and 75% and 30%, respectively, was due to gastrointestinal absorption. Mouth rinsing reduced the systemic exposure of indacaterol by approximately 35% but had no relevant effect on the exposure of MF. Dose-normalized AUClast for indacaterol inhaled via the BRZ device was 2.3-fold higher than QMF149 via the TH device. All treatments had a good safety profile and were well tolerated. Data from this study and comparison with inhalation of indacaterol via the BRZ device suggest that the latter was more efficient than the TH device regarding lung delivery of indacaterol.

PurposeThe International Conference on Harmonisation E14 guideline mandates an intensive cardiac safety evaluation in a clinical thorough QT study, typically in healthy subjects, for all new non-antiarrhythmic drugs with systemic bioavailability. This thorough QT study investigated the effects of therapeutic (2 mg) and supratherapeutic (10 mg) doses of siponimod (BAF312) on cardiac repolarization in healthy subjects. MethodsThe study was a randomized, double-blind, parallel-group, placebo- and moxifloxacin-controlled, multiple oral dose study. Eligible subjects were randomly assigned to 3 groups to receive siponimod (up-titration to 2 and 10 mg over 18 days), placebo (Days −1 to 18), or moxifloxacin 400 mg Days 10 and 18). Triplicate ECGs were extracted at prespecified time points from Holter ECGs recorded from 1 hour predose until 24 hours postdose at baseline and on-treatment assessment Days 10 and 18. The primary pharmacodynamic variable was the time-matched, placebo-corrected, baseline-adjusted mean QTcF (ΔΔQTcF) at steady-state conditions. In addition, the pharmacokinetic parameters of siponimod and its main circulating metabolite M3 and its metabolite M5 were evaluated. FindingsOf the 304 enrolled subjects, 281 (92.4%) were included in the pharmacodynamic analysis and 270 (88.8%) completed the study. The upper bounds of the 2-sided 90% confidence intervals (CIs) for ΔΔQTcF at both siponimod doses were within the regulatory threshold of 10 milliseconds (ms) at all predefined on-treatment time points, with the absence of any dose-related effects. The highest observed upper limits of the 2-sided 90% CIs of 9.8 and 9.6 ms for therapeutic and supratherapeutic doses, respectively, were both observed at 3 hours postdose. No treatment-emergent QTc values >480 ms and no QTc increases of >60 ms from baseline were observed. Similar results were obtained with individualized heart rate correction of cardiac repolarization (QTcI). Assay validity was demonstrated by maximum ΔΔQTcF of >5 ms after 400 mg moxifloxacin on both on-treatment assessment days. The selected supratherapeutic dose produced approximately 5-fold higher exposures (Cmax and AUC) than the therapeutic dose, and was considered appropriate to investigate the effects of siponimod on QT/QTc at substantial multiples of the anticipated maximum therapeutic exposure. ImplicationsThe findings provide evidence that siponimod is not associated with a significant arrhythmogenic potential related to QT prolongation.

We investigated whether moxifloxacin-induced QTc prolongations in Japanese and Caucasian healthy male volunteers were significantly different. A two period, randomized, crossover, ICH-E14-compliant thorough QT (TQT) study compared placebo-corrected changes in QTc interval from baseline (ΔΔQTc F) and concentration-effect relationships following administration of placebo and 400 mg moxifloxacin to 40 healthy male volunteers from each ethnic population. The point estimates of ΔΔQTc F for each population, and the difference between the two, were calculated at a geometric mean Cmax of moxifloxacin using a linear mixed effects model. The concentration-effect slopes of the two populations were also compared. Equivalence was concluded if the two-sided 90% confidence interval of the difference in ΔΔQTc F was contained within -5 ms to +5 ms limits and the ratio of the slopes was between 0.5 and 2. There were no statistically significant differences between the two populations studied, Japanese vs. Caucasians, respectively, for moxifloxacin Cmax (3.27 ± 0.6 vs. 2.98 ± 0.7 µg ml(-1) ), ΔΔQTc F (9.63 ± 1.15 vs. 11.46 ± 1.19 ms at Cmax of 3.07 µg ml(-1) ) and concentration-response slopes (2.58 ± 0.62 vs. 2.34 ± 0.64 ms per µg ml(-1) ). The difference in the two ΔΔQTc F of -1.8 (90% CI -4.6, 0.9) and the ratio of the two slopes (1.1; 90% CI 0.63, 1.82) were within pre-specified equivalence limits. Moxifloxacin-induced QTc prolongations did not differ significantly between the Japanese and Caucasian subjects. However, before our findings are more widely generalized, further studies in other populations and with other QT-prolonging drugs are needed to clarify whether inter-ethnic differences in QT sensitivity exist and whether ethnicity of the study population may affect the outcome of a TQT study.

Ranolazine and metformin may be frequently co-administered in subjects with chronic angina and co-morbid type 2 diabetes mellitus (T2DM). The potential for a drug-drug interaction was explored in two phase 1 clinical studies in subjects with T2DM to evaluate the pharmacokinetics and safety of metformin 1000 mg BID when administered with ranolazine 1000 mg BID (Study 1, N = 28) or ranolazine 500 mg BID (Study 2, N = 25) as compared to metformin alone. Co-administration of ranolazine 1000 mg BID with metformin 1000 mg BID resulted in 1.53- and 1.79-fold increases in steady-state metformin Cmax and AUCtau , respectively; co-administration of ranolazine 500 mg BID with metformin 1000 mg BID resulted in 1.22- and 1.37-fold increases in steady-state metformin Cmax and AUCtau , respectively. Co-administration of ranolazine and metformin was well tolerated in these T2DM subjects, with no serious adverse events or drug-related adverse events leading to discontinuation. The most common adverse events were nausea, diarrhea, and dizziness. These findings are consistent with a dose-related interaction between ranolazine and metformin, and suggest that a dose adjustment of metformin may not be required with ranolazine 500 mg BID; whereas, the metformin dose should not exceed 1700 mg of total daily dose when using ranolazine 1000 mg BID.

Background and ObjectivesThe effects of age and sex on apixaban pharmacokinetics and pharmacodynamics were studied.MethodsThis was an open-label, single-dose, 2 × 2 factorial study. Healthy young (aged 18–40 years) and elderly (aged ≥65 years) male and female subjects received a single oral 20 mg dose of apixaban. Blood and urine samples were collected for pharmacokinetic and pharmacodynamic (blood only) analyses. Subjects were monitored for adverse events throughout the study.ResultsSeventy-nine subjects were enrolled into four groups: young males (n = 20), elderly males (n = 20), young females (n = 20) and elderly females (n = 19). Age did not affect the maximum observed plasma concentration (C max). The mean area under the concentration–time curve from time zero extrapolated to infinite time (AUC∞) was 32 % greater in elderly subjects than in young subjects. The mean C max and AUC∞ values were 18 and 15 % higher, respectively, in females than in males. The time course of the mean international normalized ratio (INR), modified prothrombin time (mPT) and anti-Xa activity tracked the apixaban concentration–time curve. All three pharmacodynamic measures exhibited a positive linear correlation with the plasma apixaban concentration. Differences in the mean INR, mPT and anti-Xa activity between age and sex groups were small (<15 % at the maximum mean values) and were generally related to pharmacokinetic differences. However, anti-Xa activity demonstrated less variability than the INR or mPT, and may have utility as a bioassay for apixaban. Apixaban was well tolerated, with no serious adverse events.ConclusionThere were no clinically meaningful age- or sex-related differences in the pharmacokinetics and pharmacodynamics of apixaban that would require dose modification on the basis of age or sex alone.

To assess withdrawal-related adverse event (AE) rates following abrupt clobazam discontinuation in Phase I trials and gradual clobazam tapering (2–3weeks) following discontinuation from III trials met the criteria for potential/III trials, we evaluated AE data from four multiple-dosage Phase I trials (duration: 8–34days). Therapeutic (20 and 40mg/day) and supratherapeutic clobazam dosages (120 and 160mg/day) were administered. Adverse events (AEs) were also assessed for patients with Lennox–Gastaut syndrome enrolled in Phase II (OV-1002) and Phase III (OV-1012) studies (duration≤15weeks) and in the open-label extension (OLE) trial OV-1004 (≤5years). Potential withdrawal-related AEs were identified by preferred terms, provided that the AEs occurred ≥1day following and ≤30days after the last clobazam doses, or were deemed withdrawal symptoms by investigators. Clinical Institute Withdrawal Assessment for Benzodiazepines (CIWA-B) scale was used to evaluate withdrawal intensity in three of the four Phase I trials. A total of 207 participants in Phase I trials received steady-state clobazam dosages of 20–160mg/day, 182 received clobazam dosages of ≥40mg/day, and 94 received clobazam dosages of ≥120mg/day. Abrupt clobazam discontinuation led to 193 withdrawal-related AEs for 68 Phase I participants. Nearly 50% of AEs occurred after discontinuation of clobazam dosages of ≥120mg/day. Adverse events were mild or moderate and included headache (14% of Phase I participants), insomnia (12.6%), tremor (10.1%), and anxiety (8.7%). The CIWA-B scores varied (range: 0–59). Most scores were <30, indicating possible mild benzodiazepine withdrawal. III trials met the criteria for potential/III patients received clobazam dosages of ≤40mg/day, and those in the OLE trial received clobazam dosages of ≤80mg/day. Eighty-seven patients discontinued clobazam and were gradually tapered. No withdrawal-related AEs or incidences of status epilepticus were reported. Withdrawal-related AEs observed in Phase I studies following abrupt clobazam discontinuation at therapeutic and supratherapeutic dosages were generally mild. No withdrawal-related AEs occurred when dosages were tapered over 3weeks, after short- or long-term clobazam use (≤5years).

This double-blind, randomized, placebo- and positive-controlled, parallel-group study evaluated the effect of vortioxetine (Lu AA21004), an investigational multimodal antidepressant, on QT interval in accordance with current guidelines of the International Conference on Harmonisation (ICH-E14). A total of 340 healthy men were randomized to receive 1 of 4 treatments for 14 days: (1) vortioxetine 10 mg once daily (QD), (2) vortioxetine 40 mg QD, (3) placebo QD, or (4) placebo QD on Days 1 through 13 followed by a single dose of moxifloxacin 400 mg (positive control). The primary endpoint was the largest time-matched, baseline-adjusted least-squares (LS) mean difference for the individual-corrected QT interval (QTcNi [linear]) between vortioxetine and placebo. Alternative QT correction formulas (i.e., Fredericia [QTcF], Bazett [QTcB], Framingham [QTcFm], and QTcNi [nonlinear]) were used as secondary endpoints. The upper bound of the 2-sided 90% confidence interval around the LS mean difference from placebo for baseline-adjusted QTcNi (linear), QTcF, QTcB, QTcFm, and QTcNi (nonlinear) did not exceed 10 ms at any time point after multiple doses of vortioxetine 10 mg (therapeutic) or 40 mg (supratherapeutic). Overall, the study results indicate that vortioxetine is unlikely to affect cardiac repolarization in healthy subjects.