ABSTRACT
BACKGROUND: In studies of drug effects on electrocardiographic parameters, the level of precision in measuring QTc interval changes will influence a study's ability to detect small effects. METHODS: Variability data from investigational, placebo and moxifloxacin treatments from seven thorough QT studies performed by the same sponsor were analyzed with the objective to compare the performance of two commonly used approaches for ECG interval measurements: semiautomated (SA) and the high-precision QT (HPQT) analysis. Five studies were crossover and two parallel. Harmonized procedures were implemented to ensure similar experimental conditions across studies. ECG replicates were extracted serially from continuous 12-lead recordings at predefined time points from subjects supinely resting. The variability estimates were based on the time-point analysis of change-from-baseline QTcF as the dependent variable for the standard primary analysis of previous thorough QT studies. The residual variances were extracted for each study and ECG technique. RESULTS: High-precision QT resulted in a substantial reduction in ∆QTc variability as compared to SA. A reduction in residual variability or approximately 50% was achieved in both crossover and parallel studies, both for the active comparison (drug vs. placebo) and for assay sensitivity (moxifloxacin vs. placebo) data. CONCLUSIONS: High-precision QT technique significantly reduces QT interval variability and thereby the number of subjects needed to exclude small effects in QT studies. Based on this assessment, the sample size required to exclude a QTc effect >10 ms with 90% power is reduced from 35 with SA to 18 with HPQT, if a 3 ms underlying drug effect is assumed.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Electrocardiography/drug effects , Fluoroquinolones/pharmacology , Heart Conduction System/drug effects , Adult , Female , Healthy Volunteers , Heart Rate/drug effects , Humans , Male , Moxifloxacin , Research DesignABSTRACT
PURPOSE: Sacubitril/valsartan (LCZ696) is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) indicated to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with chronic heart failure (NYHA class II-IV) and reduced ejection fraction. This study was aimed to evaluate the effect of single oral therapeutic (400 mg) and supratherapeutic (1200 mg) doses of LCZ696 on cardiac repolarization. METHOD: This randomized double-blind crossover study in healthy male subjects compared the effect of therapeutic and supratherapeutic doses of LCZ696 with placebo and moxifloxacin 400 mg (open-label treatment) as positive control. The primary assessment was mean baseline- and placebo-corrected QTcF (∆∆QTcF; Fridericia correction). Additional assessments included the ∆∆QTcB (Bazett's correction), PR interval, QRS duration, heart rate (HR), LCZ696 pharmacokinetics, pharmacokinetic/pharmacodynamic relationships, and safety. RESULTS: Of the 84 subjects enrolled, 81 completed the study. The maximum upper bound of the two-sided 90 % confidence interval for ∆∆QTcF for LCZ696 400 mg and 1200 mg were <10 ms, and assay sensitivity was confirmed with moxifloxacin. No relevant treatment-emergent changes were observed in any of the ECG-derived parameters with LCZ696 or placebo, and the incidence of adverse events was comparable among the treatment groups. CONCLUSION: Single therapeutic and supratherapeutic doses of LCZ696 did not affect cardiac repolarization as defined by the E14 ICH guidelines.
Subject(s)
Aminobutyrates/administration & dosage , Angiotensin Receptor Antagonists/administration & dosage , Tetrazoles/administration & dosage , Valsartan/administration & dosage , Adolescent , Adult , Aminobutyrates/adverse effects , Aminobutyrates/blood , Aminobutyrates/pharmacokinetics , Aminobutyrates/pharmacology , Angiotensin Receptor Antagonists/adverse effects , Angiotensin Receptor Antagonists/pharmacokinetics , Angiotensin Receptor Antagonists/pharmacology , Biphenyl Compounds/blood , Cross-Over Studies , Double-Blind Method , Drug Combinations , Electrocardiography/drug effects , Heart/drug effects , Heart/physiology , Heart Rate/drug effects , Humans , Male , Middle Aged , Tetrazoles/adverse effects , Tetrazoles/pharmacokinetics , Tetrazoles/pharmacology , Valsartan/adverse effects , Valsartan/pharmacokinetics , Valsartan/pharmacology , Young AdultABSTRACT
PURPOSE: LCZ696 (sacubitril/valsartan), an angiotensin receptor neprilysin inhibitor, is indicated for chronic heart failure (HF) and reduced ejection fraction (HFrEF) to reduce the risk of cardiovascular death and hospitalization for HF. Following oral administration, LCZ696 provides systemic exposure to valsartan and sacubitril (a prodrug), and its metabolite sacubitrilat (the active neprilysin inhibitor, formerly named as LBQ657), which is eliminated primarily via renal route. Since renal dysfunction is a common comorbidity in patients with HF, two open-label studies assessing the effect of mild, moderate, and severe renal impairment were conducted. METHODS: Patients with mild (N = 8; creatinine clearance [CrCl] 50 to ≤80 mL/min), moderate (N = 8; CrCl 30 to <50 mL/min), and severe (N = 6; CrCl <30 mL/min) renal impairment and matching healthy subjects (CrCl >80 mL/min) for each severity group were enrolled to assess the pharmacokinetics of LCZ696 analytes following administration of LCZ696 400 mg once daily (QD) on days 1 and 5. RESULTS: The steady-state Cmax and AUC0-24h of sacubitril and valsartan were unchanged in patients with renal impairment compared with healthy subjects. However, the steady-state Cmax of sacubitrilat was increased by â¼60 % in patients irrespective of degree of renal impairment; half-life increased from 12 h (in healthy subjects) to 21.1, 23.7, and 38.5 h, respectively; and AUC0-24h was increased 2.10-, 2.24-, and 2.70-fold, respectively, in patients with mild, moderate, and severe renal impairment. CONCLUSION: Renal dysfunction increases exposure to sacubitrilat while not impacting sacubitril and valsartan exposure. LCZ696 was generally well tolerated in patients with renal impairment.
Subject(s)
Aminobutyrates/pharmacokinetics , Angiotensin Receptor Antagonists/pharmacokinetics , Renal Insufficiency/metabolism , Tetrazoles/pharmacokinetics , Adult , Aminobutyrates/adverse effects , Aminobutyrates/blood , Angiotensin Receptor Antagonists/adverse effects , Angiotensin Receptor Antagonists/blood , Biphenyl Compounds , Drug Combinations , Female , Glomerular Filtration Rate , Humans , Kidney/physiology , Male , Middle Aged , Renal Insufficiency/physiopathology , Tetrazoles/adverse effects , Tetrazoles/blood , ValsartanABSTRACT
1. Sacubitril/valsartan (LCZ696) is an angiotensin receptor neprilysin inhibitor (ARNI) providing simultaneous inhibition of neprilysin (neutral endopeptidase 24.11; NEP) and blockade of the angiotensin II type-1 (AT1) receptor. 2. Following oral administration, [(14)C]LCZ696 delivers systemic exposure to valsartan and AHU377 (sacubitril), which is rapidly metabolized to LBQ657 (M1), the biologically active neprilysin inhibitor. Peak sacubitril plasma concentrations were reached within 0.5-1 h. The mean terminal half-lives of sacubitril, LBQ657 and valsartan were â¼1.3, â¼12 and â¼21 h, respectively. 3. Renal excretion was the dominant route of elimination of radioactivity in human. Urine accounted for 51.7-67.8% and feces for 36.9 to 48.3 % of the total radioactivity. The majority of the drug was excreted as the active metabolite LBQ657 in urine and feces, total accounting for â¼85.5% of the total dose. 4. Based upon in vitro studies, the potential for LCZ696 to inhibit or induce cytochrome P450 (CYP) enzymes and cause CYP-mediated drug interactions clinically was found to be low.
Subject(s)
Aminobutyrates/metabolism , Angiotensin II Type 1 Receptor Blockers/metabolism , Tetrazoles/metabolism , Valsartan/metabolism , Adult , Biphenyl Compounds , Drug Combinations , Humans , Neprilysin/antagonists & inhibitorsABSTRACT
Central Nervous System (CNS)-related safety concerns are major contributors to delays and failure during the development of new candidate drugs (CDs). CNS-related safety data on 141 small molecule CDs from five pharmaceutical companies were analyzed to identify the concordance between rodent multi-parameter neurofunctional assessments (Functional Observational Battery: FOB, or Irwin test: IT) and the five most common adverse events (AEs) in Phase I clinical trials, namely headache, nausea, dizziness, fatigue/somnolence and pain. In the context of this analysis, the FOB/IT did not predict the occurrence of these particular AEs in man. For AEs such as headache, nausea, dizziness and pain the results are perhaps unsurprising, as the FOB/IT were not originally designed to predict these AEs. More unexpected was that the FOB/IT are not adequate for predicting 'somnolence/fatigue' nonclinically. In drug development, these five most prevalent AEs are rarely responsible for delaying or stopping further progression of CDs. More serious AEs that might stop CD development occurred at too low an incidence rate in our clinical dataset to enable translational analysis.
Subject(s)
Behavior, Animal/drug effects , Central Nervous System Diseases/chemically induced , Central Nervous System/drug effects , Clinical Trials, Phase I as Topic , Drug-Related Side Effects and Adverse Reactions/etiology , Toxicity Tests/methods , Animals , Central Nervous System/physiopathology , Central Nervous System Diseases/physiopathology , Dose-Response Relationship, Drug , Drug-Related Side Effects and Adverse Reactions/physiopathology , Humans , Mice , Rats , Reproducibility of Results , Risk Assessment , Species SpecificityABSTRACT
Substantial efforts have been recently committed to develop coronavirus disease-2019 (COVID-19) medications, and Hydroxychloroquine alone or in combination with Azithromycin has been promoted as a repurposed treatment. Although these drugs may increase cardiac toxicity risk, cardiomyocyte mechanisms underlying this risk remain poorly understood in humans. Therefore, we evaluated the proarrhythmia risk and inotropic effects of these drugs in the cardiomyocyte contractility-based model of the human heart. We found Hydroxychloroquine to have a low proarrhythmia risk, whereas Chloroquine and Azithromycin were associated with high risk. Hydroxychloroquine proarrhythmia risk changed to high with low level of K+, whereas high level of Mg2+ protected against proarrhythmic effect of high Hydroxychloroquine concentrations. Moreover, therapeutic concentration of Hydroxychloroquine caused no enhancement of elevated temperature-induced proarrhythmia. Polytherapy of Hydroxychloroquine plus Azithromycin and sequential application of these drugs were also found to influence proarrhythmia risk categorization. Hydroxychloroquine proarrhythmia risk changed to high when combined with Azithromycin at therapeutic concentration. However, Hydroxychloroquine at therapeutic concentration impacted the cardiac safety profile of Azithromycin and its proarrhythmia risk only at concentrations above therapeutic level. We also report that Hydroxychloroquine and Chloroquine, but not Azithromycin, decreased contractility while exhibiting multi-ion channel block features, and Hydroxychloroquine's contractility effect was abolished by Azithromycin. Thus, this study has the potential to inform clinical studies evaluating repurposed therapies, including those in the COVID-19 context. Additionally, it demonstrates the translational value of the human cardiomyocyte contractility-based model as a key early discovery path to inform decisions on novel therapies for COVID-19, malaria, and inflammatory diseases.
Subject(s)
Antiviral Agents/adverse effects , COVID-19 Drug Treatment , Cardiotoxicity , Chloroquine/adverse effects , Hydroxychloroquine/adverse effects , Myocytes, Cardiac/drug effects , Adult , Aged , Aged, 80 and over , Antiviral Agents/administration & dosage , Azithromycin/administration & dosage , Azithromycin/adverse effects , Chloroquine/administration & dosage , Female , Humans , Hydroxychloroquine/administration & dosage , Male , Middle Aged , Risk Assessment , SARS-CoV-2 , United StatesABSTRACT
Umibecestat, an orally active ß-secretase inhibitor, reduces the production of amyloid beta-peptide that accumulates in the brain of patients with Alzheimer's disease. The echocardiogram effects of umibecestat, on QTcF (Fridericia-corrected QT), on PR and QRS and heart rate (HR), were estimated by concentration-effect modeling. Three phase I/II studies with durations up to 3 months, with 372 healthy subjects over a wide age range, including both sexes and 2 ethnicities, were pooled, providing a large data set with good statistical power. No clinically relevant effect on QTcF, PR interval, QRS duration, or HR were observed up to supratherapeutic doses. The upper bound of 90% confidence intervals of the ∆QTcF was below the 10 ms threshold of regulatory concern for all concentrations measured. Prespecified sensitivity analysis confirmed the results in both sexes, in those over and below 60 years, and in Japanese subjects. All conclusions were endorsed by the US Food and Drug Administration (FDA).
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Electrocardiography/drug effects , Long QT Syndrome/diagnosis , Oxazines/adverse effects , Adult , Aged , Aged, 80 and over , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Dose-Response Relationship, Drug , Female , Heart Rate/drug effects , Humans , Long QT Syndrome/chemically induced , Male , Middle Aged , Moxifloxacin/administration & dosage , Oxazines/administration & dosage , Randomized Controlled Trials as Topic , Young AdultABSTRACT
PURPOSE: To evaluate the effect of lapatinib on the QTc interval and ECG parameters in patients with advanced solid tumors. METHODS: This was a multicenter, placebo-controlled study in subjects with advanced solid tumors. Subjects were administered two doses of matching placebo on day 1, 12 h apart and one dose in the morning on day 2. Two doses of lapatinib 2000 mg were administered orally on day 3, 12 h apart and one dose in the morning on day 4. Twelve-lead digital ECGs were extracted from continuous Holter recordings at pre-specified time points over the 24-h period on days 2 and 4. Venous blood samples for lapatinib concentrations were obtained immediately following the ECGs. RESULTS: A maximum mean baseline-adjusted, placebo time-matched increase in QTcF, (ddQTcF) in the evaluable, (EV) population (n = 37) of 8.8 ms (90% CI 4.1, 13.4) occurred approximately 10 h after the third lapatinib dose. These results were consistent with those in the pharmacodynamic, PD population, (n = 52) (ddQTcF = 7.9 ms; 90% CI 4.1, 11.7). No subject experienced QTcF increases from baseline of > 60 ms on lapatinib or placebo. The geometric mean lapatinib Cmax of 3902 ng/mL was observed at 3.6 h post-dose. CONCLUSIONS: These data show a relevant, treatment-related increase in QTcF after treatment with three doses of lapatinib 2000 mg. This study confirms the need for caution in patients with solid tumors treated with lapatinib, and who are concomitantly receiving drugs that are strong CYP3A inhibitors and/or prolong the QTc.
Subject(s)
Antineoplastic Agents/therapeutic use , Lapatinib/therapeutic use , Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/pharmacology , Cross-Over Studies , Female , Humans , Lapatinib/pharmacology , Male , Middle Aged , Neoplasms/pathology , Young AdultABSTRACT
PURPOSE: Octreotide (OCT) has been successfully used for treatment of acromegaly and neuroendocrine tumors for more than 30 years. However, long-term safety of OCT has not been documented in placebo-controlled setting. This present analysis pooled safety data from two similarly-designed, randomized, and placebo-controlled studies to evaluate long-term safety of long-acting OCT (20, 30 mg); targeted post-hoc analyzes focused on cardiac, hepatic, and renal safety. METHODS: Two studies (NCT00131144, NCT001308450) were conducted in patients with diabetic retinopathy (OCT20 = 191, OCT30 = 348, placebo = 347). In this analysis, patients were stratified based on baseline glomerular filtration rate. Hepatic, cardiac, and renal adverse events (AEs) were identified by standardized MedDRA queries. RESULTS: Median duration of exposure was >3.5 years. Most common AEs reported with OCT were diarrhea, cholelithiasis, hypoglycemia, nasopharyngitis, and hypertension. Incidence of cardiac events (QT prolongation and arrhythmia) with OCT20 and OCT30 were comparable to placebo (OCT20, RR = 1.11 [95% CI, 0.61-2.03]; OCT30, RR = 1.09 [95% CI, 0.70-1.68]). For ECG findings, changes in QTcF were similar in treatment groups, and outliers did not exceed 480 ms. Incidence of cardiac ischemia was lower with OCT than placebo (OCT20 = 12.6%, OCT30 = 10.6%, placebo = 15.3%). Incidence of liver-related AEs was higher with OCT30 than placebo (RR = 2.04 [95% CI, 1.28-3.26]); incidences were comparable with OCT20 and placebo (RR = 1.50 [95% CI, 0.69-3.25]). Overall incidences of renal AEs were comparable between treatment groups (OCT20 = 5.8%; OCT30 = 6.3%; placebo = 7.2%). Drug-related SAEs were reported more frequently with OCT (OCT20 = 7.9%; OCT30 = 10.1%; placebo = 3.5%); predominantly gallbladder-related, GI-related, and hypoglycemia. CONCLUSIONS: The results from these long-term placebo-controlled studies confirm the established safety profile of long-acting OCT, in particular low risk of cardiac, hepatic and renal toxicity in a high-risk population.
Subject(s)
Cholelithiasis/chemically induced , Diabetic Retinopathy/drug therapy , Diarrhea/chemically induced , Hypertension/chemically induced , Hypoglycemia/chemically induced , Octreotide/adverse effects , Adult , Aged , Double-Blind Method , Female , Humans , Male , Middle Aged , Octreotide/therapeutic useABSTRACT
BACKGROUND: New anticoagulants that combine effective anticoagulation with low bleeding rates are still sought after. We investigated the safety, pharmacokinetics, and pharmacodynamics of otamixaban, a direct factor Xa inhibitor, in patients with stable coronary artery disease. METHODS: This was a randomized, placebo-controlled, double-blind, multicenter study in 119 patients with stable coronary artery disease taking maintenance doses of their comedication. Of these patients, 50% had mild renal impairment (creatinine clearance >45 mL/min but <80 mL/min). Patients were randomized in a 4:1 ratio to receive either otamixaban or placebo as a 1-minute bolus followed by a 24-hour continuous infusion. Anti-factor Xa activity, clotting times (activated partial thromboplastin time, dilute prothrombin time, Russell's viper venom test), and international normalized ratio were measured. RESULTS: All patients completed the study according to the protocol. No major or minor bleeding occurred according to Thrombosis in Myocardial Infarction criteria. Anti-factor Xa activity and anticoagulant effect were measurable early after the start of the infusion and remained during the infusion. Upon cessation, these effects declined rapidly and returned to baseline within 6 hours after the end of infusion. Anti-factor Xa activity coincided with the otamixaban plasma concentrations. The fold changes from baseline at the end of infusion with regard to the clotting times ranged from 1.7 to 4.4 (1.15 for placebo), 1.29 to 3.15 (0.98 for placebo), and 1.19 to 2.11 (0.94 for placebo) for Russell's viper venom test, dilute prothrombin time, and activated partial thromboplastin time, respectively, and ranged from 0.94 to 1.70 (0.94 for placebo) for the international normalized ratio. CONCLUSION: In patients with stable coronary artery disease taking maintenance doses of their usual concomitant medication, otamixaban exerts a rapid onset of anticoagulation and anti-factor Xa activity. Our data provide evidence that further studies are warranted to investigate the safety and efficacy of otamixaban in the target population.
Subject(s)
Coronary Disease/drug therapy , Cyclic N-Oxides/pharmacology , Factor Xa Inhibitors , Pyridines/pharmacology , Adult , Aged , Area Under Curve , Comorbidity , Coronary Disease/metabolism , Cyclic N-Oxides/pharmacokinetics , Cyclic N-Oxides/therapeutic use , Double-Blind Method , Female , Humans , Infusions, Intravenous , International Normalized Ratio , Male , Metabolic Clearance Rate , Middle Aged , Pyridines/pharmacokinetics , Pyridines/therapeutic useABSTRACT
PURPOSE: The conduct of thorough QTc (TQT) studies is often challenging with compounds that are characterized by limited tolerability in healthy individuals. This is applicable to several central nervous system drugs, including mavoglurant acting as a selective allosteric modulator of metabotropic glutamate receptor 5. This TQT study describes the use of a single intravenous dosing regimen as an alternate approach allowing for sufficiently high Cmax values while controlling tolerability. METHODS: This study was a randomized, placebo- and active-controlled, 4-period, crossover, TQT study composed of 2 sequential phases. In the pilot phase, the safety and tolerability profile of 10-minute infusions of 25, 37.5, and 50 mg of mavoglurant was assessed in 36 healthy individuals. In the TQT phase, individuals received in random sequence single intravenous doses of mavoglurant (25 and 50 mg) and placebo and an oral dose of moxifloxacin (400 mg). FINDINGS: Mavoglurant was well tolerated up to a single intravenous dose of 50 mg, and supratherapeutic Cmax values were achieved that were approximately 2-fold higher than at the multiple maximum tolerated dose and more than 3-fold higher relative to therapeutic plasma concentrations. The upper bound of the 2-sided 90% CI of Fridericia-corrected placebo- and baseline-adjusted QTc intervals (QTcFs) did not exceed 10 milliseconds at any postdose time point for both mavoglurant doses. The pharmacokinetic and pharmacodynamic analysis confirmed the lack of an association between mavoglurant plasma concentrations and ΔΔQTcF data over the entire range of plasma concentration data at 25 and 50 mg of mavoglurant. An outlier analysis revealed no individuals with newly identified QTcF intervals >480 milliseconds or any QTcF prolongations >60 milliseconds compared with baseline in any of the treatment groups. Hence, the lack of any clinically relevant QTc prolongation was found for therapeutic and supratherapeutic single intravenous doses of 25 and 50 mg of mavoglurant. IMPLICATIONS: This TQT study describes the use of single intravenous dosing as an alternate approach to achieve supratherapeutic plasma concentrations as required per the International Council for Harmonisation E14 guideline with compounds characterized by exposure related tolerability limitations. The increased Cmax/AUC ratio compared with conventional oral dosing may contribute to a reduced incidence of adverse events that appear more related to overall exposure.
Subject(s)
Heart/drug effects , Indoles/pharmacology , Receptor, Metabotropic Glutamate 5/antagonists & inhibitors , Administration, Intravenous , Adult , Allosteric Regulation , Cross-Over Studies , Dose-Response Relationship, Drug , Double-Blind Method , Electrocardiography , Fluoroquinolones/pharmacology , Heart/physiology , Heart Conduction System/drug effects , Humans , Indoles/pharmacokinetics , Male , Moxifloxacin , Pilot ProjectsABSTRACT
AIMS: Concomitant renin-angiotensin-aldosterone system blockade and natriuretic peptide system enhancement may provide unique therapeutic benefits to patients with heart failure and reduced ejection fraction (HFrEF). This study assessed the pharmacodynamics and pharmacokinetics of LCZ696 in patients with HFrEF. METHODS: This was an open-label, noncontrolled single-sequence study. After a 24-h run-in period, patients (n = 30) with HFrEF (EF ≤ 40%; NYHA class II-IV) received LCZ696 100 mg twice daily (bid) for 7 days and 200 mg bid for 14 days, along with standard treatment for heart failure (HF) (except angiotensin-converting enzyme inhibitors [ACEIs] or angiotensin receptor blockers [ARBs]). RESULTS: On Day 21, significant increases were observed in the plasma biomarkers indicative of neprilysin and RAAS inhibition (ratio-to-baseline: cyclic guanosine monophosphate [cGMP], 1.38; renin concentration and activity, 3.50 and 2.27, respectively; all, P < 0.05). Plasma NT-proBNP levels significantly decreased at all the time points on Days 7 and 21; plasma aldosterone and endothelin-1 levels significantly decreased on Day 21 (all, P < 0.05). Following administration of LCZ696, the Cmax of sacubitril (neprilysin inhibitor prodrug), LBQ657 (active neprilysin inhibitor), and valsartan were reached within 0.5, 2.5, and 2 h. Between 100- and 200-mg doses, the Cmax and AUC0-12 h for sacubitril and LBQ657 were approximately dose-proportional while that of valsartan was less than dose-proportional. CONCLUSIONS: Treatment with LCZ696 for 21 days was well tolerated and resulted in plasma biomarker changes indicative of neprilysin and RAAS inhibition in patients with HF. The pharmacokinetic exposure of the LCZ696 analytes in patients with HF observed in this study is comparable to that observed in the pivotal Phase III study.
Subject(s)
Aminobutyrates/pharmacokinetics , Angiotensin Receptor Antagonists/pharmacokinetics , Heart Failure/drug therapy , Stroke Volume , Tetrazoles/pharmacokinetics , Ventricular Function, Left , Aged , Aldosterone/blood , Aminobutyrates/administration & dosage , Angiotensin Receptor Antagonists/administration & dosage , Angiotensin Receptor Antagonists/adverse effects , Angiotensin Receptor Antagonists/blood , Area Under Curve , Biomarkers/blood , Biphenyl Compounds , Chronic Disease , Drug Administration Schedule , Drug Combinations , Endothelin-1/blood , Female , Heart Failure/blood , Heart Failure/physiopathology , Humans , Male , Middle Aged , Natriuretic Peptide, Brain/blood , Neprilysin/antagonists & inhibitors , Neprilysin/metabolism , Peptide Fragments/blood , Renin-Angiotensin System/drug effects , Russia , Tetrazoles/administration & dosage , Treatment Outcome , ValsartanABSTRACT
BACKGROUND: Angiotensin receptor neprilysin inhibitors (ARNi), beyond blocking angiotensin II signaling, augment natriuretic peptides by inhibiting their breakdown by neprilysin. The myocardial effects of ARNi have been little studied until recently. We hypothesized that LCZ696 attenuates left ventricular (LV) remodeling after experimental myocardial infarction (MI), and that this may be contributed to by inhibition of hypertrophy and fibrosis in cardiac cells. METHODS AND RESULTS: One week after MI, adult male Sprague-Dawley rats were randomized to treatment for 4 weeks with LCZ696 (68 mg/kg body weight perorally; MI-ARNi, n=11) or vehicle (MI-vehicle, n=6). Five weeks after MI, MI-ARNi versus MI-vehicle demonstrated lower LV end-diastolic diameter (by echocardiography; 9.7±0.2 versus 10.5±0.3 mm), higher LV ejection fraction (60±2 versus 47±5%), diastolic wall strain (0.23±0.02 versus 0.13±0.02), and circular strain (-9.8±0.5 versus -7.3±0.5%; all P<0.05). LV pressure-volume loops confirmed improved LV function. Despite similar infarct size, MI-ARNi versus MI-vehicle had lower cardiac weights (P<0.01) and markedly reduced fibrosis in peri-infarct and remote myocardium. Angiotensin II-stimulated incorporation of 3[H]leucine in cardiac myocytes and 3[H]proline in cardiac fibroblast was used to evaluate hypertrophy and fibrosis, respectively. The neprilysin inhibitor component of LCZ696, LBQ657, inhibited hypertrophy but not fibrosis. The angiotensin receptor blocker component of LCZ696, valsartan inhibited both hypertrophy and fibrosis. Dual valsartan+LBQ augmented the inhibitory effects of valsartan and the highest doses completely abrogated angiotensin II-mediated effects. CONCLUSIONS: LCZ696 attenuated cardiac remodeling and dysfunction after MI. This may be contributed to by superior inhibition of LCZ696 on cardiac fibrosis and cardiac hypertrophy than either stand-alone neprilysin inhibitor or angiotensin receptor blocker.
Subject(s)
Aminobutyrates/therapeutic use , Angiotensin Receptor Antagonists/therapeutic use , Cardiomyopathy, Hypertrophic/prevention & control , Myocardial Infarction/complications , Myocardium/pathology , Tetrazoles/therapeutic use , Ventricular Function, Left/drug effects , Ventricular Remodeling/drug effects , Animals , Biphenyl Compounds , Cardiomyopathy, Hypertrophic/etiology , Cardiomyopathy, Hypertrophic/physiopathology , Disease Models, Animal , Drug Combinations , Fibrosis/complications , Fibrosis/drug therapy , Fibrosis/pathology , Male , Myocardial Infarction/therapy , Neprilysin/antagonists & inhibitors , Rats , Rats, Sprague-Dawley , Treatment Outcome , ValsartanABSTRACT
Reduced repolarization reserve and increased transmural dispersion of repolarization (TDR) are known risk factors for Torsade de Pointes development, but less is known about the role of apex-to-base (apicobasal) repolarization in arrhythmogenesis. Three needles were inserted in rabbit left ventricle to record unipolar electrograms from endocardium to epicardium and base to apex. Total repolarization interval (TRI) and peak-to-end repolarization interval (Tp) were assessed after quinidine (n = 6) and D,L-sotalol (n = 6) perfusion in combination with the IKs inhibitor chromanol 293B. About 30 µM D,L-sotalol increased TRI and Tp more at the base (TRI + 40 ± 4 %; Tp +89 ± 11 %) relative to the apex (TRI + 28 ± 3 %, Tp + 30 ± 8 %). Similar results were obtained with quinidine: TRI and Tp increased more at the base compared to the apex. No significant differences were recorded from the endocardium to the epicardium. Our results show that combined IKr + IKs block prolonged TRI and Tp significantly more at the ventricular base than at the apex, in the absence of transmural dispersion of refractoriness. Regional changes in TRI and Tp indicate the contribution of apicobasal dispersion to arrhythmogenicity compared to TDR in a rabbit heart model.
Subject(s)
Arrhythmias, Cardiac/etiology , Animals , Anti-Arrhythmia Agents/pharmacology , Antioxidants/metabolism , Chromans/pharmacology , Electrophysiologic Techniques, Cardiac , Endocardium/physiopathology , Pericardium/physiopathology , Quinidine/pharmacology , Rabbits , Sotalol/pharmacology , Sulfonamides/pharmacology , Torsades de Pointes/etiologyABSTRACT
The aim of this study was to evaluate the effects of subcutaneous pasireotide on cardiac repolarization in healthy volunteers. Healthy volunteers were randomized to one of four treatment sequences (n = 112) involving four successive treatments in different order: pasireotide 600 µg (therapeutic dose) or 1,950 µg (maximum tolerated dose) bid by subcutaneous injection (sc), placebo injection and oral moxifloxacin. Maximum ΔΔQTcI occurred 2 hours post-dose for both doses of pasireotide. Mean ΔΔQTcI was 13.2 milliseconds (90% CI: 11.4, 15.0) and 16.1 milliseconds (90% CI: 14.3, 17.9) for the 600 and 1,950 µg bid doses, respectively. Maximal placebo-subtracted change in QTcI from baseline for moxifloxacin was 11.1 (90% CI: 9.3, 12.9) milliseconds. Both pasireotide doses caused a reduction in heart rate: maximal heart rate change compared with placebo occurred at 1 hour for pasireotide 600 µg bid and at 0.5 hours for pasireotide 1,950 µg bid, with heart rate reductions of 10.4 and 14.9 bpm, respectively. At the therapeutic dose of 600 µg, pasireotide has a modest QT-prolonging effect. The relatively small increase of â¼3 milliseconds in ΔΔQTcI in the presence of a 3.25-fold increase in dose suggests a relatively flat doseeffect relationship of pasireotide on ΔΔQTcI in healthy volunteers. No safety concerns for pasireotide were identified during the study.
Subject(s)
Heart/drug effects , Somatostatin/analogs & derivatives , Adolescent , Adult , Aza Compounds/pharmacokinetics , Cross-Over Studies , Dose-Response Relationship, Drug , Electrocardiography/drug effects , Female , Fluoroquinolones , Heart Rate/drug effects , Humans , Injections, Subcutaneous , Long QT Syndrome/chemically induced , Long QT Syndrome/physiopathology , Male , Middle Aged , Models, Statistical , Moxifloxacin , Quinolines/pharmacokinetics , Sample Size , Somatostatin/administration & dosage , Somatostatin/pharmacokinetics , Somatostatin/pharmacology , Young AdultABSTRACT
Twenty-four (24) Caucasian male subjects completed a single-blind, randomised, three-treatment, three-period, cross-over study. In each treatment phase, subjects received a single dose of 144 mg pipamperone dihydrochloride (CAS 2448-68-2) (equivalent to 120 mg pipamperone; CAS 1893-33-0) as either the reference product (3 x 40 mg tablets), test product A (3 x 40 mg tablets) or test product B (1 x 120 mg tablet). Each consecutive dosing was separated by a washout period of 14 days. Following each dosing, venous blood samples were collected over a period of 120 h for the determination of plasma pipamperone concentrations by high-performance liquid chromatography. The most common drug related adverse events, ranging from mild to moderate in intensity, were bloodshot eyes, nasal congestion, dry mouth, hypotension and dizziness. The geometric mean Cmax of pipamperone for both the reference product and test product A was 266 ng/ml and for test product B 263 ng/ml. The geometric mean AUC0-infinity was 3107 ng.h/ml for the reference product, 3229 ng.h/ml for test product A and 3108 ng.h/ml for test product B. The two test products were shown to be bioequivalent to the reference product with respect to all pharmacokinetic variables investigated.