Effect of single doses of IV palonosetron, up to 2.25 mg, on the QTc interval duration: a double-blind, randomized, parallel group study in healthy volunteers.

PURPOSE: The use of serotonin type 3 (5-HT3) receptor antagonists (RAs) in the prevention of nausea and vomiting caused by emetogenic chemotherapy is part of a comprehensive management strategy for patients undergoing chemotherapy. Electrocardiographic effects have been reported in patients after intravenous administration of 5-HT3 RAs. The present study investigated the electrocardiogram (ECG) profile of the 5-HT3 RA palonosetron following International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) E14 Guidelines. METHODS: A total of 221 healthy subjects (101 females, 120 males) were randomized in this phase I, double-blind, double-dummy, parallel group study and assigned to one of five treatments: placebo, palonosetron (0.25, 0.75, or 2.25 mg), or moxifloxacin (400 mg). ECGs were recorded for 24 h pre-dosing until 48 h post-dose. The primary endpoint was the placebo time-matched and baseline-subtracted individual QTc interval prolongation (ΔΔQTcI). RESULTS: The QTc interval was not prolonged after administration of palonosetron (ΔΔQTcI upper confidence interval was <10 ms for all time points in all palonosetron treatment groups). Assay sensitivity was confirmed with the expected change in the QTc interval after administration of the positive control moxifloxacin. CONCLUSIONS: Palonosetron, even at supratherapeutic doses, has no effect on cardiac repolarization as measured by the QTc interval in a validated controlled clinical trial.

Moxifloxacin-induced QTc interval prolongations in healthy male Japanese and Caucasian volunteers: a direct comparison in a thorough QT study.

AIM: We investigated whether moxifloxacin-induced QTc prolongations in Japanese and Caucasian healthy male volunteers were significantly different. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

ICH E14 Q & A (R1) document: perspectives on the updated recommendations on thorough QT studies.

The International Conference on Harmonization (ICH) guidance ICH E14 provides recommendations, focusing on a clinical 'thorough QT/QTc (TQT) study', to evaluate the QT liability of a drug during its development. An Implementation Working Group (IWG) was also established to assist the sponsors with any uncertainties and clarify any ambiguities. In April 2012, the IWG updated its June 2008 version of the Questions and Answers document to address additional issues. These include the gender of the study population, a reasonable approach to evaluating QTc changes in late stage clinical development and the recommended approach to correcting the measured QT interval. This commentary provides our observations and, when appropriate, recommendations, on these issues. We review briefly evidence that suggests that (i) the greater QT effect observed in females is not entirely related to differences in drug exposure and (ii) the Fridericia correction of measured QT interval is adequate for a majority of TQT studies. Until further evidence suggests otherwise, we recommend balanced gender representation in TQT studies, unless warranted otherwise, and for positive studies, subgroup analysis of key data by common demographic variables including the gender and ethnicity. We provide a general scheme for ECG monitoring in late phase clinical trials and consider that while intensive monitoring and centralized reading of ECGs in late phase clinical trials is the norm when a TQT study is positive, there are other circumstances that also call for high quality ECG reading. Therefore, locally read ECGs should only be acceptable as long as accurate high quality ECG data can be guaranteed.

Assessing Prolongation of the Corrected QT Interval with Bedaquiline and Delamanid Coadministration to Predict the Cardiac Safety of Simplified Dosing Regimens.

Delamanid and bedaquiline are two drugs approved to treat drug-resistant tuberculosis, and each have been associated with corrected QT interval (QTc) prolongation. We aimed to investigate the relationships between the drugs' plasma concentrations and the prolongation of observed QT interval corrected using Fridericia's formula (QTcF) and to evaluate their combined effects on QTcF, using a model-based population approach. Furthermore, we predicted the safety profiles of once daily regimens. Data were obtained from a trial where participants were randomized 1:1:1 to receive delamanid, bedaquiline, or delamanid + bedaquiline. The effect on QTcF of delamanid and/or its metabolite (DM-6705) and the pharmacodynamic interactions under coadministration were explored based on a published model between bedaquiline's metabolite (M2) and QTcF. The metabolites of each drug were found to be responsible for the drug-related QTcF prolongation. The final drug-effect model included a competitive interaction between M2 and DM-6705 acting on the same cardiac receptor and thereby reducing each other's apparent potency, by 28% (95% confidence interval (CI), 22-40%) for M2 and 33% (95% CI, 24-54%) for DM-6705. The generated combined effect was not greater but close to "additivity" in the analyzed concentration range. Predictions with the final model suggested a similar QT prolonging potential with simplified, once-daily dosing regimens compared with the approved regimens, with a maximum median change from baseline QTcF increase of 20 milliseconds in both regimens. The concentrations-QTcF relationship of the combination of bedaquiline and delamanid was best described by a competitive binding model involving the two main metabolites. Model predictions demonstrated that QTcF prolongation with simplified once daily regimens would be comparable to currently used dosing regimens.

QT effects of bedaquiline, delamanid, or both in patients with rifampicin-resistant tuberculosis: a phase 2, open-label, randomised, controlled trial.

BACKGROUND: Bedaquiline and delamanid are the first drugs of new classes registered for tuberculosis treatment in 40 years. Each can prolong the QTc interval, with maximum effects occurring weeks after drug initiation. The cardiac safety and microbiological activity of these drugs when co-administered are not well-established. Our aim was to characterise the effects of bedaquiline, delamanid, or both on the QTc interval, longitudinally over 6 months of multidrug treatment, among patients with multidrug-resistant or rifampicin-resistant tuberculosis taking multidrug background therapy. METHODS: ACTG A5343 is a phase 2, open-label, randomised, controlled trial in which adults with multidrug-resistant or rifampicin-resistant tuberculosis receiving multidrug background treatment were randomly assigned 1:1:1 by centrally, computer-generated randomisation, by means of permuted blocks to receive bedaquiline, delamanid, or both for 24 weeks. Participants were enrolled at TASK in Cape Town and the South African Tuberculosis Vaccine Initiative in Worcester, both in South Africa, and Hospital Maria Auxiliadora in Peru. Individuals with QTc greater than 450 ms were excluded. HIV-positive participants received dolutegravir-based antiretroviral therapy. Clofazimine was disallowed, and levofloxacin replaced moxifloxacin. ECG in triplicate and sputum cultures were done fortnightly. The primary endpoint was mean QTcF change from baseline (averaged over weeks 8-24); cumulative culture conversation at week 8-24 was an exploratory endpoint. Analyses included all participants who initiated study tuberculosis treatment (modified intention-to-treat population). This trial is registered with ClinicalTrials.gov, NCT02583048 and is ongoing. FINDINGS: Between Aug 26, 2016 and July 13, 2018, of 174 screened, 84 participants (28 in each treatment group, and 31 in total with HIV) were enrolled. Two participants did not initiate study treatment (one in the delamanid group withdrew consent and one in the bedaquiline plus delamanid group) did not meet the eligibility criterion). Mean change in QTc from baseline was 12·3 ms (95% CI 7·8-16·7; bedaquiline), 8·6 ms (4·0-13·1; delamanid), and 20·7 ms (16·1-25·3) (bedaquiline plus delamanid). There were no grade 3 or 4 adverse QTc prolongation events and no deaths during study treatment. Cumulative culture conversion by week 8 was 21 (88%) of 24 (95% CI 71-97; bedaquiline), 20 (83%) of 24 (65-95; delamanid), and 19 (95%) of 20 (79-100; bedaquiline plus delamanid) and was 92% (77-99) for bedaquiline, 91% (76-99), for delamanid, and 95% (79-100) for bedaquiline plus delamanid at 24 weeks. INTERPRETATION: Combining bedaquiline and delamanid has a modest, no more than additive, effect on the QTc interval, and initial microbiology data are encouraging. This study provides supportive evidence for use of these agents together in patients with multidrug-resistant or rifampicin-resistant tuberculosis with normal baseline QTc values. FUNDING: Division of AIDS, National Institutes of Health.

No cardiac effects of therapeutic and supratherapeutic doses of rupatadine: results from a 'thorough QT/QTc study' performed according to ICH guidelines.

AIMS: To evaluate the effects of therapeutic and supratherapeutic doses of rupatadine on cardiac repolarization in line with a 'thorough QT/QTc study' protocol performed according to International Conference on Harmonization guidelines. METHODS: This was a randomized (gender-balanced), parallel-group study involving 160 healthy volunteers. Rupatadine, 10 and 100 mg day(-1), and placebo were administered single-blind for 5 days, whilst moxifloxacin 400 mg day(-1) was given on days 1 and 5 in open-label fashion. ECGs were recorded over a 23-h period by continuous Holter monitoring at baseline and on treatment days 1 and 5. Three 10-s ECG samples were downloaded at regular intervals and were analysed independently. The primary analysis of QTc was based on individually corrected QT (QTcI). Treatment effects on QTcI were assessed using the largest time-matched mean difference between the drug and placebo (baseline-subtracted) for the QTcI interval. A negative 'thorough QT/QTc study' is one where the main variable is around < or =5 ms, with a one-sided 95% confidence interval that excludes an effect >10 ms. RESULTS: The validity of the trial was confirmed by the fact that the moxifloxacin-positive control group produced the expected change in QTcI duration (around 5 ms). The ECG data for rupatadine at both 10 and 100 mg showed no signal effects on the ECG, after neither single nor repeated administration. Furthermore, no pharmacokinetic/pharmacodynamic relationship, gender effects or clinically relevant changes in ECG waveform outliers were observed. No deaths or serious or unexpected adverse events were reported. CONCLUSIONS: This 'thorough QT/QTc study' confirmed previous experience with rupatadine and demonstrated that it had no proarrhythmic potential and raised no concerns regarding its cardiac safety.

A Thorough QT/QTc Study With Laquinimod, a Novel Immunomodulator in Development for Multiple Sclerosis and Huntington Disease.

In this randomized double-blind study, 4 groups of healthy subjects (50 per arm) participated to evaluate the effect of laquinimod, an oral treatment in development for multiple sclerosis and Huntington disease, on the QTc interval. Subjects received a dose of either 0.6 or 1.2 mg/day laquinimod for 14 days, placebo for 14 days, or 13 days of placebo followed by a dose of 400 mg moxifloxacin on day 14. Continuous 12-lead electrocardiograms were recorded on day -1 (baseline) and days 14 to 17,  and quadruplicate electrocardiograms were extracted at predefined time points. The primary measure was time-matched change from baseline in individual QTc (QTcI), and an analysis of variance was conducted on the placebo-corrected change from baseline data (ddQTcI). Pharmacokinetic-pharmacodynamic and safety assessments were included. Results showed that the upper limits of the 2-sided 90%CI for ddQTcI for both laquinimod doses were below 10 millisconds at all time points, whereas lower limits for moxifloxacin were above 5 milliseconds. No notable changes in ECG parameters were observed. Pharmacokinetic/pharmacodynamic analysis showed no positive correlation between laquinimod plasma levels and QTcI. In conclusion, laquinimod was not found to affect cardiac repolarization or to cause prolongation of QTcI at doses of 0.6 and 1.2 mg/day.

Effects of buprenorphine on QT intervals in healthy subjects: results of 2 randomized positive- and placebo-controlled trials.

OBJECTIVES: To study the effect of transdermal buprenorphine on QTc prolongation at dose levels of 10, 40, and 80 mcg/h, (BTDS 10, BTDS 40, BTDS 80). METHODS: Two randomized, placebo- and positive-controlled, parallel-group, dose-escalating clinical studies evaluated healthy adult subjects randomized to BTDS, placebo, or moxifloxacin in the first study; and to BTDS only, BTDS plus naltrexone, naltrexone alone at the same dose, placebo, or moxifloxacin in the second study. QT intervals were corrected for heart rate using data from each individual subject (QTcI). RESULTS: In the first study (n = 44), the maximum upper bounds of the 90% confidence interval (CI) for mean placebo-corrected change from baseline in QTcI across 13 time points over 24 h were: 10.0 msec for BTDS 10 (Day 6) and 13.3 msec for BTDS 40 (Day 13); and 17.0 msec (Day 6) and 15.5 msec (Day 13) for moxifloxacin, respectively. Similarly, in the second study (n = 66), the upper bound of the 90% CI for mean placebo-corrected change from baseline for QTcI was under 10 msec at all time points for BTDS 10 (maximum upper bound, 5.63 msec), over 10 msec at 5 time points for BTDS 40 (maximum 11.81 msec) and over 10 msec at all 13 time points for BTDS 80 (maximum, 14.14 msec). Naltrexone administered with BTDS eliminated the QTcI prolongation seen with supratherapeutic BTDS doses (BTDS 40, BTDS 80) administered without naltrexone. CONCLUSIONS: At the therapeutic dose of 10 mcg/h, BTDS has no clinically significant effect on QTc. At supratherapeutic doses of 40 and 80 mcg/h, BTDS treatment produces prolongation of QTcI similar in magnitude to that produced by a 400 mg dose of moxifloxacin. Despite the modest, dose-dependent increase in QTcI noted in these studies, transdermal buprenorphine has not been associated with proarrhythmic effects.

Benefits of Centralized ECG Reading in Clinical Oncology Studies.

BACKGROUND: Many clinical trials of investigational oncologic agents utilize electrocardiogram (ECG) machine measurements of QTc, for inclusion/exclusion and dosing decisions, though their reliability in this setting has not been established. METHODS: We compared the digital ECG machine QTc measurements with those obtained by a centralized ECG core lab on more than 270,000 consecutive ECGs collected from 299 clinical oncology trials. RESULTS: The mean difference between the ECG machine measurements and the central measured QTcF was 1.8 ± 15.7 milliseconds. In addition, 29.7% of ECGs with an ECG machine-measured QTcF >450 milliseconds had a centrally measured QTcF <450 milliseconds, 44.6% of ECGs with an ECG machine-measured QTcF >470 milliseconds had a centrally measured QTcF <470 milliseconds, and 77.2% of ECGs with an ECG machine-measured QTcF >500 milliseconds had a centrally measured QTcF <500 milliseconds. The likelihood of a large discrepancy between the ECG machine- and centrally measured value for QTcF increased at both the high and low ends of the range of ECG machine QTcF measurements. CONCLUSIONS: While on average ECG machine-measured QTcF values were very similar to the central core lab measurements; there were very significant discrepancies which will have important implications for patient recruitment for clinical oncology trials as well as for patient safety during dosing with new oncologic agents. Reliance on ECG machine QTc measurements during clinical oncology trials may lead to unnecessary exclusion of patients as well as unneeded treatment interruptions.

A randomized trial comparing the cardiac rhythm safety of moxifloxacin vs levofloxacin in elderly patients hospitalized with community-acquired pneumonia.

CONTEXT: Antimicrobial cardiac safety is of particular concern during the treatment of community-acquired pneumonia (CAP) in elderly patients, due to the presence of comorbid conditions and the use of multiple medications that may individually or synergistically affect cardiac repolarization. STUDY OBJECTIVE: To assess the cardiac rhythm safety of moxifloxacin vs levofloxacin in elderly patients hospitalized with CAP. DESIGN AND SETTING: Prospective, randomized, double-blind trial conducted at 47 hospitals in the United States. PATIENTS: Subjects > or = 65 years old with clinical signs/symptoms of CAP requiring initial parenteral therapy, including those with comorbidities. The safety population included 394 patients: 51.3% male; 85.3% white; mean age, 77.8 years. Two-thirds of the patients were > 75 years old, and 74.1% had a history of cardiac disease. INTERVENTIONS: Patients received IV/oral moxifloxacin (400 mg qd) or IV/oral levofloxacin (500 mg qd) for 7 to 14 days. Safety evaluations included 72 h of digital continuous 12-lead Holter monitoring, 12-lead ECGs at baseline and at maximum serum concentration on day 3, and adverse events. MAIN OUTCOME MEASURES: The primary safety end point was a composite of ventricular arrhythmia events based on Holter monitoring. RESULTS: Holter monitor data were available for 387 patients (192 receiving moxifloxacin and 195 receiving levofloxacin). Sixteen moxifloxacin-treated patients (8.3%) and 10 levofloxacin-treated patients (5.1%) had a primary composite cardiac event (p = 0.29); most events were nonsustained ventricular tachycardia (VT) [14 patients receiving moxifloxacin, 7.3%; and 10 patients receiving levofloxacin, 5.1%]. One moxifloxacin-treated patient had sustained monomorphic VT (> 30 s), and one levofloxacin-treated patient had torsade de pointes. Mean +/- SD QTc (Fridericia formula) change on day 3 was + 6.4 +/- 23.2 ms for moxifloxacin and - 2.5 +/- 22.9 ms for levofloxacin (p = 0.04). No deaths clearly related to study drugs occurred during the observation period. CONCLUSIONS: IV/oral moxifloxacin, although known to cause QTc interval prolongation, has a comparable cardiac rhythm safety profile to IV/oral levofloxacin in high-risk elderly patients with CAP.

Update on Cardiovascular Safety of Tyrosine Kinase Inhibitors: With a Special Focus on QT Interval, Left Ventricular Dysfunction and Overall Risk/Benefit.

We previously reviewed the cardiovascular safety of 16 tyrosine kinase inhibitors (TKIs), approved for use in oncology as of 30 September 2012. Since then, the indications for some of them have been widened and an additional nine TKIs have also been approved as of 30 April 2015. Eight of these nine are indicated for use in oncology and one (nintedanib) for idiopathic pulmonary fibrosis. This report is an update on the cardiovascular safety of those 16 TKIs, including the post-marketing data concerning their pro-arrhythmic effects, and reviews the cardiovascular safety of the nine new TKIs approved since (afatinib, cabozantinib, ceritinib, dabrafenib, ibrutinib, lenvatinib, nintedanib, ponatinib, and trametinib). As before, we focus on specific aspects of cardiovascular safety, namely their potential to induce QT interval prolongation, left ventricular (LV) dysfunction and hypertension but now also summarise the risks of arterial thromboembolic events (ATEs) associated with these agents. Of the newer TKIs, cabozantinib and ceritinib have been shown to induce a mild to moderate degree of QTc interval prolongation while cardiac dysfunction has been reported with the use of afatinib, dabrafenib, lenvatinib, ponatinib and trametinib. The label for axitinib was revised to include a new association with cardiac dysfunction. Hypertension is associated with cabozantinib, lenvatinib, nintedanib, ponatinib and trametinib. Ponatinib, within 10 months of its approval in December 2012, required voluntary (temporary) suspension of its marketing until significant safety revisions (restricted indication, additional warnings and precautions about the risk of arterial occlusion and thromboembolic events and amended dose) were made to its label. Compared with the previous 16 TKIs, more of the recently introduced TKIs are associated with the risk of LV dysfunction, and fewer with QT prolongation. Available data on morbidity and mortality associated with TKIs, together with post-marketing experience with lapatinib and ponatinib, emphasise the need for effective pharmacovigilance and ongoing re-assessment of their risk/benefit after approval of these novel agents. If not adequately managed, these cardiovascular effects significantly decrease the quality of life and increase the morbidity and mortality in a population already at high risk. Evidence accumulated over the last decade suggests that their clinical benefit, although worthwhile, is modest and extends only to progression-free survival and complete response without any effect on overall survival. During uncontrolled use in routine clinical practice, their risk/benefit is likely to be inferior to that perceived from highly controlled clinical trials.

Effect of bendamustine in combination with rituximab on QT interval duration in patients with advanced de novo indolent non-Hodgkin or mantle cell lymphoma.

PURPOSE: Bendamustine is used in chronic lymphocytic leukemia (first-line) and indolent B-cell non-Hodgkin lymphoma (NHL) that progressed during/within 6 months of treatment with rituximab or a rituximab-containing regimen. This study was a postapproval commitment to investigate bendamustine's effect on cardiac repolarization in treatment-naïve adults with advanced indolent NHL/mantle cell lymphoma (MCL). METHODS: In this multicenter, open-label, phase 3 study, patients received 6-8 28-day cycles of bendamustine (90 mg/m(2), days 1 and 2) and rituximab (375 mg/m(2), day 1). Exclusions included a history of cardiac conditions with potential for QT prolongation. The primary endpoint was change in Fridericia-corrected QT (QTcF; 3 electrocardiograms per time point) on day 2 of cycle 1, from just before infusion to end of infusion (immediately postinfusion, coinciding with maximum plasma concentration of bendamustine). Change 1 h postinfusion was also measured. Exploratory assessments included specific QTcF outlier analyses (new QTcF >500 ms, change >60 ms) and morphological changes. RESULTS: Of the 54 enrolled patients (mean age, 62.9 years), 53 received ≥1 dose; 49 completed ≥6 cycles. Mean QTcF change from baseline was 6.7 ms at end of infusion; no mean changes >20 ms were detected ≤1 h postinfusion. No patients met specific outlier criteria at end of infusion or 1 h postinfusion. No morphological changes were detected. CONCLUSIONS: In this small treatment-naïve population with advanced NHL/MCL, bendamustine did not produce a clinically relevant increase in mean QTcF on the second infusion day. The potential for delayed effects on QT interval after 1 h was not evaluated.

Evaluation of vardenafil and sildenafil on cardiac repolarization.

This novel study evaluated the effects of vardenafil and sildenafil on QT and corrected QT (QTc) duration using a model that minimizes experimental error to obtain the most accurate assessment of observed QTc effects. A placebo-controlled and positive-controlled, period-balanced, double-blinded, 6-way crossover study evaluated therapeutic and supratherapeutic oral doses of vardenafil (10 and 80 mg, respectively) and sildenafil (50 and 400 mg, respectively), therapeutic doses of moxifloxacin (400 mg), and a placebo in 58 healthy men (mean age 53 years), with dosing every 3 days. Six replicate, 12-lead, digital electrocardiograms (ECGs) were recorded at 3 time points before and 5 time points after dosing to cover the time course of maximum exposure to study drugs and their metabolites. An independent laboratory blindly analyzed approximately 17,000 ECGs. For the placebo, mean change in QTcF (Fridericia) duration 1 hour after dose (approximate Tmax of vardenafil and sildenafil) was 0 ms (+/-0.7 SD). QT/QTc variability was small across regimens, indicating statistically powerful results. Moxifloxacin demonstrated an expected 8-ms mean change and was the only drug to prolong absolute QT. Placebo-corrected mean changes in QTcF duration (90% confidence interval) at 1 hour after dose were 8 ms (range 6 to 9) for vardenafil 10 mg and 6 ms (range 5 to 8) for sildenafil 50 mg. QTci (linear and nonlinear per patient) yielded similar trends: 4 ms (range 3 to 6) for vardenafil 10 mg and 4 ms (range 2 to 5) for sildenafil 50 mg. Dose response demonstrated very shallow QTc relations for study drugs. Therapeutic and supratherapeutic doses produced only small increases in the QTcF interval, which were considered to be clinically irrelevant. This well-controlled, statistically powerful study in middle-aged men demonstrated that vardenafil and sildenafil produced no increase of absolute QT and only similar, small increases of the QTc interval, with a shallow dose-response curve. The study design and conduct may serve as a guide for future QT assessment of new drugs.

Electrocardiographic effects of rivastigmine.

The electrocardiographic (ECG) effects of rivastigmine treatment were assessed in mild to moderately severe Alzheimer's disease (AD) by analysis of four 26-week, double-blind, multicenter, placebo-controlled, phase III clinical trials. Of an initial 2791 patients, 77% completed treatment. Seventy-one percent required at least one concomitant medication for conditions other than AD, with 34% requiring cardiovascular medications. Safety assessments included ECGs, adverse events, vital signs, and clinical laboratory parameters. Pooled 12-lead ECG data were analyzed by an independent cardiologist blinded to treatment group and clinical information. Heart rate, PR, QRS, and QTc intervals did not differ significantly between treatment and placebo groups. Percentage change from baseline for PR, QRS, and QTc intervals was also no different. In conclusion, rivastigmine appears not to produce adverse effects on cardiac function assessed by ECG.

The pharmacokinetics and safety of single escalating oral doses of eletriptan.

The pharmacokinetics, safety, and tolerability of the 5-HT(1B/1D) agonist eletriptan were characterized in a randomized, double-blind, placebo-controlled, dose escalation study. Healthy males received single oral doses of 10 to 120 mg. Following screening and baseline measurements, plasma and saliva eletriptan concentrations were measured at intervals over 48 hours and 24 hours, respectively. Samples were analyzed using high-performance liquid chromatography with ultraviolet detection. Both the maximum plasma concentration and the area under the plasma eletriptan concentration-time curve showed an essentially linear relationship to the administered dose. Eletriptan exhibited a median time to maximum plasma concentration of 1 to 1.25 hours and a mean elimination half-life of 3.6 to 7.0 hours. Mean salivary-plasma ratios for pharmacokinetic parameters generally remained constant across the 30 to 90 mg dose range. Eletriptan was well tolerated, with mostly mild and transient adverse events. In conclusion, oral doses of eletriptan in the therapeutic range were rapidly absorbed and exhibited essentially linear plasma and saliva pharmacokinetics.

Effects of a new antibacterial, telavancin, on cardiac repolarization (QTc interval duration) in healthy subjects.

Telavancin is a rapidly bactericidal antibiotic with multiple mechanisms of action against gram-positive bacteria. Preclinical and early clinical data suggested possible effects on cardiac repolarization requiring the conduct of a definitive evaluation of QT effects in healthy subjects. A total of 160 subjects were randomized into four groups to receive placebo (telavancin vehicle), telavancin at a dose of 7.5 mg/kg or 15 mg/kg, or moxifloxacin 400 mg (positive control). All medications were administered once daily for 3 days as 60-minute IV infusions. Sixteen ECGs were obtained over 24 hours following an infusion of D5W (baseline) and following Day 3 infusions of each medication. ECGs were analyzed digitally in a blinded fashion by a validated core ECG laboratory. The primary endpoint was QT data corrected for heart rate by the Fridericia formula (QTcF). Placebo-corrected mean changes in QTcF values for 7.5 mg/kg telavancin, 15 mg/kg telavancin, and moxifloxacin were 4.1 msec, 4.5 msec, and 9.2 msec, respectively. The mean change from baseline in QTcF for moxifloxacin, which served as the assay-sensitive positive control in the study, helped to establish that telavancin had a minimal effect on QT prolongation. No subject had a QTcF > or = 450 msec, and none experienced clinically significant ECG abnormalities. The telavancin treatment groups were not significantly different from each other. There was no correlation of the magnitude of change in QTc and plasma concentrations of telavancin. Telavancin has a < 5-msec mean effect on cardiac repolarization, with a flat-dose response over a two-fold exposure range.

Electrocardiographic response to intravenous and intraarterial injection of iosimenol (a new, iodinated, non-ionic, iso-osmolar contrast medium).

Serious arrhythmias, sometimes related to the injection of iodinated contrast media, are known complications of cardiac angiography. A new, iodine-based, non-ionic, iso-osmolar x-ray contrast media is in development for use in these procedures. This contrast medium, iosimenol, has a lower viscosity, higher electrolyte content, and higher iodine concentration than other available iso-osmolar contrast media. The present study is a retrospective re-read and centralized analysis of the electrocardiographic response to intravenous and non-cardiac intraarterial injections of iosimenol, placebo, or iodixanol (Visipaque; GE Healthcare, Inc) in a total of 167 healthy subjects and patients enrolled in early clinical trials. No clinically relevant changes in heart rate and rhythm, morphology, atrioventricular conduction, or ventricular repolarization were noted after injection of any of the test articles in these studies. These results, despite the limited number of patients in these trials, suggest that iosimenol can be used safely in larger populations.

Hepatotoxicity of tyrosine kinase inhibitors: clinical and regulatory perspectives.

The introduction of small-molecule tyrosine kinase inhibitors (TKIs) in clinical oncology has transformed the treatment of certain forms of cancers. As of 31 March 2013, 18 such agents have been approved by the US Food and Drug Administration (FDA), 15 of these also by the European Medicines Agency (EMA), and a large number of others are in development or under regulatory review. Unexpectedly, however, their use has been found to be associated with serious toxic effects on a number of vital organs including the liver. Drug-induced hepatotoxicity has resulted in withdrawal from the market of many widely used drugs and is a major public health issue that continues to concern all the stakeholders. This review focuses on hepatotoxic potential of TKIs. The majority of TKIs approved to date are reported to induce hepatic injury. Five of these (lapatinib, pazopanib, ponatinib, regorafenib and sunitinib) are sufficiently potent in this respect as to require a boxed label warning. Onset of TKI-induced hepatotoxicity is usually within the first 2 months of initiating treatment, but may be delayed, and is usually reversible. Fatality from TKI-induced hepatotoxicity is uncommon compared to hepatotoxic drugs in other classes but may lead to long-term consequences such as cirrhosis. Patients should be carefully monitored for TKI-induced hepatotoxicity, the management of which requires individually tailored reappraisal of the risk/benefit. The risk is usually manageable by dose adjustment or a switch to a suitable alternative TKI. Confirmation of TKI-induced hepatotoxicity can present challenges in the presence of hepatic metastasis and potential drug interactions. Its diagnosis in a patient with TKI-sensitive cancer requires great care if therapy with the TKI suspected to be causal is to be modified or interrupted as a result. Post-marketing experience with drugs such as imatinib, lapatinib and sorafenib suggests that the hepatotoxic safety of all the TKIs requires diligent surveillance.