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Background: Etripamil is a fast-acting, intranasally administered calcium-channel blocker in development for on-demand therapy outside a health-care setting for paroxysmal supraventricular tachycardia. We aimed to evaluate the efficacy and safety of etripamil 70 mg nasal spray using a symptom-prompted, repeat-dose regimen for acute conversion of atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia to sinus rhythm within 30 min., Methods: RAPID was a multicentre, randomised, placebo-controlled, event-driven trial, conducted at 160 sites in North America and Europe as part 2 of the NODE-301 study. Eligible patients were aged at least 18 years and had a history of paroxysmal supraventricular tachycardia with sustained, symptomatic episodes (≥20 min) as documented by electrocardiogram. Patients were administered two test doses of intranasal etripamil (each 70 mg, 10 min apart) during sinus rhythm; those who tolerated the test doses were randomly assigned (1:1) using an interactive response technology system to receive either etripamil or placebo. Prompted by symptoms of paroxysmal supraventricular tachycardia, patients self-administered a first dose of intranasal 70 mg etripamil or placebo and, if symptoms persisted beyond 10 min, a repeat dose. Continuously recorded electrocardiographic data were adjudicated, by individuals masked to patient assignment, for the primary endpoint of time to conversion of paroxysmal supraventricular tachycardia to sinus rhythm for at least 30 s within 30 min after the first dose, which was measured in all patients who administered blinded study drug for a confirmed atrioventricular-nodal-dependent event. Safety outcomes were assessed in all patients who self-administered blinded study drug for an episode of perceived paroxysmal supraventricular tachycardia. This trial is registered at ClinicalTrials.gov, NCT03464019, and is complete., Findings: Between Oct 13, 2020, and July 20, 2022, among 692 patients randomly assigned, 184 (99 from the etripamil group and 85 from the placebo group) self-administered study drug for atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia, with diagnosis and timing confirmed. Kaplan-Meier estimates of conversion rates by 30 min were 64% (63/99) with etripamil and 31% (26/85) with placebo (hazard ratio 2·62; 95% CI 1·66-4·15; p<0·0001). Median time to conversion was 17·2 min (95% CI 13·4-26·5) with the etripamil regimen versus 53·5 min (38·7-87·3) with placebo. Prespecified sensitivity analyses of the primary assessment were conducted to test robustness, yielding supporting results. Treatment-emergent adverse events occurred in 68 (50%) of 99 patients treated with etripamil and 12 (11%) of 85 patients in the placebo group, most of which were located at the administration site and were mild or moderate, and all of which were transient and resolved without intervention. Adverse events occurring in at least 5% of patients treated with etripamil were nasal discomfort (23%), nasal congestion (13%), and rhinorrhea (9%). No serious etripamil-related adverse events or deaths were reported., Interpretation: Using a symptom-prompted, self-administered, initial and optional-repeat-dosing regimen, intranasal etripamil was well tolerated, safe, and superior to placebo for the rapid conversion of atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia to sinus rhythm. This approach could empower patients to treat paroxysmal supraventricular tachycardia themselves outside of a health-care setting, and has the potential to reduce the need for additional medical interventions, such as intravenous medications given in an acute-care setting., Funding: Milestone Pharmaceuticals., Competing Interests: Declaration of interests BSS, PTS, BM, MC, PRK, JPP, SDP, and AJC are consultants for Milestone Pharmaceuticals. AJC has received grants and personal fees from Boehringer Ingelheim, Bayer, Pfizer, Bristol-Myers Squibb, and Daiichi Sankyo; personal fees from Medtronic, Boston Scientific, Menarini, and Biotronik; and support from Anthos, Sanofi, Abbott, GlaxoSmithKline, and Johnson & Johnson. PRK has received personal fees from Acesion Pharma, Allergan, Astellas Pharma, AstraZeneca, AtriCure, Boehringer Ingelheim, Bristol-Myers Squibb, Chattem, Correvio, Daiichi Sankyo, GlaxoSmithKline, InCarda Therapeutics, Johnson & Johnson, Medtronic, Merck, Novartis, Pfizer, Roche, and Sanofi-Aventis; serves on a data safety monitoring board for Eli Lilly; and has equity in CardioNet. SDP has received personal fees from Medtronic, Boston Scientific, Pfizer, Bristol-Myers Squibb, Janssen Pharmaceuticals, Philips, Zoll, and Sanofi-Aventis and research grants from Boston Scientific, Gilead Sciences, Pfizer, Bristol-Myers Squibb, the US Food and Drug Administration, Janssen Pharmaceuticals, Philips, Medtronic, and Sanofi-Aventis. HH has received lecture and consultancy fees from Abbott, Biotronik, Daiichi Sankyo, Pfizer-BMS, Medscape, and Springer Healthcare and unconditional research grants through the University of Antwerp and/or the University of Hasselt from Abbott, Bayer, Biotronik, Biosense Webster, Boston Scientific, Boehringer Ingelheim, Daiichi Sankyo, Fibricheck/Qompium, Medtronic, and Pfizer-BMS, all outside of the scope of this work. JLM has received grants and personal fees from Medtronic, Microport, and Sanofi. JPP has received grants for clinical research from Abbott, the American Heart Association, the Association for the Advancement of Medical Instrumentation, Bayer, Boston Scientific, iRhythm, and Philips and serves as a consultant to Abbott, AbbVie, ARCA biopharma, Bayer, Boston Scientific, Bristol Myers Squibb (Myokardia), Element Science, Itamar Medical, LivaNova, Medtronic, ElectroPhysiology Frontiers, ReCor, Sanofi, Philips, and UpToDate. AV has received personal fees from MedLumics and Adagio Medical and research grants from Bayer, Biosense Webster, and Medtronic. JMW has received personal fees from Sanofi-Aventis, Bristol-Myers Squibb, and Janssen Pharmaceuticals and a research grant from Milestone Pharmaceuticals. PTS has equity in Milestone Pharmaceuticals. DBB, FP, and SS are employees of Milestone Pharmaceuticals. JEI, MA, BSS, PD, and AJC serve on the steering committee for Milestone Pharmaceuticals. JH declares no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Aims: Current long QT syndrome (LQTS) therapy, largely based on beta-blockade, does not prevent arrhythmias in all patients; therefore, novel therapies are warranted. Pharmacological inhibition of the serum/glucocorticoid-regulated kinase 1 (SGK1-Inh) has been shown to shorten action potential duration (APD) in LQTS type 3. We aimed to investigate whether SGK1-Inh could similarly shorten APD in LQTS types 1 and 2., Methods and Results: Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and hiPSC-cardiac cell sheets (CCS) were obtained from LQT1 and LQT2 patients; CMs were isolated from transgenic LQT1, LQT2, and wild-type (WT) rabbits. Serum/glucocorticoid-regulated kinase 1 inhibition effects (300 nM-10 µM) on field potential durations (FPD) were investigated in hiPSC-CMs with multielectrode arrays; optical mapping was performed in LQT2 CCS. Whole-cell and perforated patch clamp recordings were performed in isolated LQT1, LQT2, and WT rabbit CMs to investigate SGK1-Inh (3 µM) effects on APD. In all LQT2 models across different species (hiPSC-CMs, hiPSC-CCS, and rabbit CMs) and independent of the disease-causing variant (KCNH2-p.A561V/p.A614V/p.G628S/IVS9-28A/G), SGK1-Inh dose-dependently shortened FPD/APD at 0.3-10 µM (by 20-32%/25-30%/44-45%). Importantly, in LQT2 rabbit CMs, 3 µM SGK1-Inh normalized APD to its WT value. A significant FPD shortening was observed in KCNQ1-p.R594Q hiPSC-CMs at 1/3/10 µM (by 19/26/35%) and in KCNQ1-p.A341V hiPSC-CMs at 10 µM (by 29%). No SGK1-Inh-induced FPD/APD shortening effect was observed in LQT1 KCNQ1-p.A341V hiPSC-CMs or KCNQ1-p.Y315S rabbit CMs at 0.3-3 µM., Conclusion: A robust SGK1-Inh-induced APD shortening was observed across different LQT2 models, species, and genetic variants but less consistently in LQT1 models. This suggests a genotype- and variant-specific beneficial effect of this novel therapeutic approach in LQTS., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Drug-induced QT prolongation (DI-QTP) is a clinical entity in which administration of a human ether-à-go-go-related gene/rapid delayed rectifier potassium current blocker such as dofetilide prolongs the cardiac action potential duration (APD) and the QT interval on the electrocardiogram. Inhibition of serum and glucocorticoid regulated kinase-1 (SGK1) reduces the APD at 90% repolarization (APD90) in induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) derived from patients with congenital long QT syndrome., Objective: Here, we test the efficacy of 2 novel SGK1 inhibitors-SGK1-I1 and SGK1-I2-in iPSC-CM models of dofetilide-induced APD prolongation., Methods: Normal iPSC-CMs were treated with dofetilide to produce a DI-QTP iPSC-CM model. SGK1-I1's and SGK1-I2's therapeutic efficacy for shortening the dofetilide-induced APD90 prolongation was compared to mexiletine. The APD90 values were recorded 4 hours after treatment using a voltage-sensing dye., Results: The APD90 was prolonged in normal iPSC-CMs treated with dofetilide (673 ± 8 ms vs 436 ± 4 ms; P < .0001). While 10 mM mexiletine shortened the APD90 of dofetilide-treated iPSC-CMs from 673 ± 4 to 563 ± 8 ms (46% attenuation; P < .0001), 30 nM of SGK1-I1 shortened the APD90 from 673 ± 8 to 502 ± 7 ms (72% attenuation; P < .0001). Additionally, 300 nM SGK1-I2 shortened the APD90 of dofetilide-treated iPSC-CMs from 673 ± 8 to 460 ± 7 ms (90% attenuation; P < .0001)., Conclusion: These novel SGK1-Is substantially attenuated the pathological APD prolongation in a human heart cell model of DI-QTP. These preclinical data support the development of this therapeutic strategy to counter and neutralize DI-QTP, thereby increasing the safety profile for patients receiving drugs with torsadogenic potential., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Long QT syndrome (LQTS) stems from pathogenic variants in KCNQ1 (LQT1), KCNH2 (LQT2), or SCN5A (LQT3) and is characterized by action potential duration (APD) prolongation. Inhibition of serum and glucocorticoid regulated kinase-1 (SGK1) is proposed as a novel therapeutic for LQTS., Objective: The study sought to test the efficacy of novel, selective SGK1 inhibitors in induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM) models of LQTS., Methods: The mexiletine (MEX)-sensitive SCN5A-P1332L iPSC-CMs were tested initially compared with a CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 SCN5A-P1332L variant-corrected isogenic control (IC). The SGK1-I1 therapeutic efficacy, compared with MEX, was tested for APD at 90% repolarization (APD90) shortening in SCN5A-P1332L, SCN5A-R1623Q, KCNH2-G604S, and KCNQ1-V254M iPSC-CMs using FluoVolt., Results: The APD90 was prolonged in SCN5A-P1332L iPSC-CMs compared with its IC (646 ± 7 ms vs 482 ± 23 ms; P < .0001). MEX shortened the APD90 to 560 ± 7 ms (52% attenuation, P < .0001). SGK1-I1 shortened the APD90 to 518 ± 5 ms (78% attenuation, P < .0001) but did not shorten the APD90 in the IC. SGK1-I1 shortened the APD90 of the SCN5A-R1623Q iPSC-CMs (753 ± 8 ms to 475 ± 19 ms compared with 558 ± 19 ms with MEX), the KCNH2-G604S iPSC-CMs (666 ± 10 ms to 574 ± 18 ms vs 538 ± 15 ms after MEX), and the KCNQ1-V254M iPSC-CMs (544 ± 10 ms to 475 ± 11ms; P = .0004)., Conclusions: Therapeutically inhibiting SGK1 effectively shortens the APD in human iPSC-CM models of the 3 major LQTS genotypes. These preclinical data support development of SGK1 inhibitors as novel, first-in-class therapy for patients with congenital LQTS., (© 2023 Heart Rhythm Society. Published by Elsevier Inc.)

Background: Pharmacologic termination of paroxysmal supraventricular tachycardia (PSVT) often requires medically supervised intervention. Intranasal etripamil, is an investigational fast-acting, nondihydropyridine, L-type calcium channel blocker, designed for unsupervised self-administration to terminate atrioventricular nodal-dependent PSVT. Phase 2 results showed potential safety and efficacy of etripamil in 104 patients with PSVT., Methods: NODE-301, a phase 3, multicenter, double-blind, placebo-controlled study evaluated the efficacy and safety of etripamil nasal spray administered, unsupervised in patients with symptomatic sustained PSVT. After a medically supervised etripamil test dose while in sinus rhythm, patients were randomized 2:1 to receive etripamil 70 mg or placebo. When PSVT symptoms developed, patients applied a cardiac monitor and attempted a vagal maneuver; if symptoms persisted, they self-administered blinded treatment. An independent Adjudication Committee reviewed continuous electrocardiogram recordings. The primary efficacy endpoint was termination of adjudicated PSVT within 5 hours after study drug administration., Results: NODE-301 accrued 156 positively adjudicated PSVT events treated with etripamil (n=107) or placebo (n=49). The hazard ratio for the primary endpoint, time-to-conversion to sinus rhythm during the 5-hour observation period, was 1.086 (95% CI, 0.726-1.623; P =0.12). In predefined sensitivity analyses, etripamil effects (compared with placebo) occurred at 3, 5, 10, 20, and 30 minutes ( P <0.05). For example, at 30 minutes, there was a 53.7% of SVT conversion in the treatment arm compared to 34.7% in the placebo arm (hazard ratio, 1.87 [95% CI, 1.09-3.22]; P =0.02). Etripamil was well tolerated; adverse events were mainly related to transient nasal discomfort and congestion (19.6% and 8.0%, respectively, of randomized treatment-emergent adverse events., Conclusions: Although the primary 5-hour efficacy endpoint was not met, analyses at earlier time points indicated an etripamil treatment effect in terminating PSVT. Etripamil self-administration during PSVT was safe and well tolerated. These results support continued clinical development of etripamil nasal spray for self-administration during PSVT in a medically unsupervised setting., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT03464019.

Presently, acute pharmacological termination of paroxysmal supraventricular tachycardia (PSVT) unresponsive to patient-initiated vagal maneuvers requires in-hospital intervention. Etripamil, a fast-acting, nondihydropyridine, L-type calcium channel blocker, is formulated as an intranasal spray to rapidly terminate atrioventricular (AV) nodal-dependent PSVT in a medically unsupervised setting. The NODE-301 study did not meet its prespecified primary end point of PSVT conversion over 5 hours following a single dose of etripamil 70 mg. However, analysis at earlier time points demonstrated etripamil treatment effect during the first 30 minutes, consistent with its expected rapid onset and short duration of action. This led to the design of the RAPID study, which includes a new dosing regimen (up to 2 etripamil 70 mg doses separated by 10 minutes) to increase the exposure and pharmacodynamic effect of etripamil. The primary objective of RAPID (NCT03464019) is to determine if etripamil self-administered by patients is superior to placebo in terminating PSVT in an at-home setting. The secondary objective is to evaluate the safety of etripamil when self-administered by patients without medical supervision. Additional efficacy end points include the proportion of patients requiring additional medical intervention in an emergency department to terminate PSVT and patient-reported outcomes. After successfully completing a test dose to assess the safety of 2 70 mg doses of etripamil during sinus rhythm, approximately 500 patients will be randomized 1:1 to etripamil or placebo to accrue 180 positively adjudicated AV nodal-dependent PSVT events for treatment with the study drug. Etripamil may offer a new alternative to the current in-hospital treatment modality, providing for safe and effective at-home termination of PSVT., (Copyright © 2022. Published by Elsevier Inc.)

Cenobamate is an antiseizure medication for uncontrolled focal seizures. This thorough QT study assessed the effects of therapeutic and supratherapeutic cenobamate doses (maximum recommended dose, 400 mg/day) on correct QT interval (QTc) in healthy adults (N = 108) randomly assigned to 1 of 3 treatments: (A) cenobamate (days 1-63) up-titrated by 50-mg increments weekly to a 200 mg/day therapeutic dose (day 35) and then by 100 mg weekly to a 500 mg/day supratherapeutic dose (day 63), with placebo-moxifloxacin (days -1 and 64); (B) moxifloxacin 400 mg (day -1; positive control), placebo-cenobamate (days 1-63), and placebo-moxifloxacin (day 64); and (C) placebo-moxifloxacin (day -1), placebo-cenobamate (days 1-64), and moxifloxacin 400 mg (day 64). The primary end point was baseline-adjusted, placebo-corrected QTc (ΔΔQTcF; corrected for heart rate [HR] by Fridericia's method) with cenobamate 200 and 500 mg/day. Baseline electrocardiographic parameters were balanced across groups. Mean ΔΔQTcF was negative throughout for cenobamate doses (largest: day 35, -10.8 milliseconds; day 63, -18.4 milliseconds). Based on concentration-QTc analysis, ∆∆QTcF effect was predicted as -9.85 and -17.14 milliseconds at mean peak plasma levels of therapeutic (200 mg/day; 23.06 μg/mL) and supratherapeutic (500 mg/day; 63.96 μg/mL) doses. Cenobamate had no clinically relevant prolonging effect on electrocardiographic parameters (eg, PR, QRS); HR effects were similar to placebo. Cenobamate showed slight dose-related shortening of QTc, but to a degree not known to be clinically relevant (no reductions ≤340 milliseconds). Cenobamate had no clinically relevant effects on HR or electrocardiographic parameters and no QTc-prolonging effect at therapeutic/supratherapeutic doses. Cenobamate is contraindicated in patients with short-QT syndrome and caution should be used when coadministering with drugs that shorten QT interval., (© 2022, The American College of Clinical Pharmacology.)

Perhexiline has been used to treat hypertrophic cardiomyopathy. In addition to its effect on carnitine-palmitoyltransferase-1, it has mixed ion channel effects through inhibition of several cardiac ion currents. Effects on cardiac ion channels expressed in mammalian cells were assayed using a manual patch-clamp technique, action potential duration (APD) was measured in ventricular trabeculae of human donor hearts, and electrocardiogram effects were evaluated in healthy subjects in a thorough QT (TQT) study. Perhexiline blocked several cardiac ion currents at concentrations within the therapeutic range (150-600 ng/mL) with IC 50 for hCav1.2 ∼ hERG < late hNav1.5. A significant APD shortening was observed in perhexiline-treated cardiomyocytes. The TQT study was conducted with a pilot part in 9 subjects to evaluate a dosing schedule that would achieve therapeutic and supratherapeutic perhexiline plasma concentrations on days 4 and 6, respectively. Guided by the results from the pilot, 104 subjects were enrolled in a parallel-designed part with a nested crossover comparison for the positive control. Perhexiline caused QTc prolongation, with the largest effect on ΔΔQTcF, 14.7 milliseconds at therapeutic concentrations and 25.6 milliseconds at supratherapeutic concentrations and a positive and statistically significant slope of the concentration-ΔΔQTcF relationship (0.018 milliseconds per ng/mL; 90%CI, 0.0119-0.0237 milliseconds per ng/mL). In contrast, the JTpeak interval was shortened with a negative concentration-JTpeak relationship, a pattern consistent with multichannel block. Further studies are needed to evaluate whether this results in a low proarrhythmic risk., (© 2021, The American College of Clinical Pharmacology.)

Atrial fibrillation (AF) is the most common sustained clinical arrhythmia, with a lifetime incidence of up to 37%, and is a major contributor to population morbidity and mortality. Important components of AF management include control of cardiac rhythm, rate, and thromboembolic risk. In this narrative review article, we focus on rhythm-control therapy. The available therapies for cardiac rhythm control include antiarrhythmic drugs and catheter-based ablation procedures; both of these are presently neither optimally effective nor safe. In order to develop improved treatment options, it is necessary to use preclinical models, both to identify novel mechanism-based therapeutic targets and to test the effects of putative therapies before initiating clinical trials. Extensive research over the past 30 years has provided many insights into AF mechanisms that can be used to design new rhythm-maintenance approaches. However, it has proven very difficult to translate these mechanistic discoveries into clinically applicable safe and effective new therapies. The aim of this article is to explore the challenges that underlie this phenomenon. We begin by considering the basic problem of AF, including its clinical importance, the current therapeutic landscape, the drug development pipeline, and the notion of upstream therapy. We then discuss the currently available preclinical models of AF and their limitations, and move on to regulatory hurdles and considerations and then review industry concerns and strategies. Finally, we evaluate potential paths forward, attempting to derive insights from the developmental history of currently used approaches and suggesting possible paths for the future. While the introduction of successful conceptually innovative new treatments for AF control is proving extremely difficult, one significant breakthrough is likely to revolutionize both AF management and the therapeutic development landscape., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Elevated blood pressure increases the risk of adverse cardiovascular events and death. Accordingly, characterizing the off-target blood pressure effects of drugs is an important component of regulatory benefit-risk assessment and post-marketing clinical decision-making. The U.S. Food and Drug Administration (FDA) released draft guidance in May 2018 outlining these considerations and seeking discussion regarding opportunities to improve or reassess methods and analytical techniques to measure and interpret the pressor effects of drugs. Toward this effort, the Duke-Margolis Center for Health Policy-under a cooperative agreement with the FDA-convened a public workshop to bring the stakeholder community together to discuss these opportunities. The following are summary statements and recommendations discussed at the workshop to improve blood pressure assessment throughout the product lifecycle, from development and regulatory review to clinical care.

Balanced multi-ion channel-blocking drugs have low torsade risk because they block inward currents. The Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative proposes to use an in silico cardiomyocyte model to determine the presence of balanced block, and absence of heart rate corrected J-T peak (J-T peak c) prolongation would be expected for balanced blockers. This study included three balanced blockers in a 10-subject-per-drug parallel design; lopinavir/ritonavir and verapamil met the primary end point of ΔΔJ-T peak c upper bound < 10 ms, whereas ranolazine did not (upper bounds of 8.8, 6.1, and 12.0 ms, respectively). Chloroquine, a predominant blocker of the potassium channel encoded by the ether-à-go-go related gene (hERG), prolonged ΔΔQTc and ΔΔJ-T peak c by ≥ 10 ms. In a separate crossover design, diltiazem (calcium block) did not shorten dofetilide-induced ΔQTc prolongation, but shortened ΔJ-T peak c and prolonged ΔT peak -T end . Absence of J-T peak c prolongation seems consistent with balanced block; however, small sample size (10 subjects) may be insufficient to characterize concentration-response in some cases., (Published 2019. This article is a U.S. Government work and is in the public domain in the USA. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Context: Increases in heart rate were seen during the clinical program for fixed-dose combination phentermine (PHEN) and topiramate (TPM), an oral medication indicated for weight management; however, the effect on cardiovascular (CV) outcomes is uncertain., Objective: The aim of the present study was to determine the extent to which the rates of major adverse CV events (MACE) in patients using PHEN and TPM (including fixed dose) differed from the MACE rates during unexposed periods., Design: Retrospective cohort study., Setting: MarketScan, US insurance billing data., Patients or Other Participants: Patients aged >18 years with ≥6 months of continuous enrollment in the database before taking PHEN and/or TPM or after stopping these medications., Interventions: PHEN and TPM, taken separately and together (including fixed dose)., Main Outcome Measures: MACE, a composite of hospitalization for acute myocardial infarction and stroke and in-hospital CV death., Results: Because the outcomes are rare and the duration of medication use was brief, few events occurred. The MACE rates among current users of PHEN/TPM, fixed-dose PHEN/TPM, and PHEN were lower than those among unexposed former users. In contrast, the rate of MACE among current users of TPM was greater than among unexposed former users [incidence rate ratio: PHEN/TPM, 0.57; 95% CI, 0.19 to 1.78; fixed-PHEN/TPM, 0.24; 95% CI, 0.03 to 1.70; PHEN, 0.56; 95% CI, 0.34 to 0.91; TPM, 1.58; 95% CI, 1.33 to 1.87)., Conclusions: Overall, the data indicated no increased risk of MACE for current PHEN/TPM users; however, the 95% CIs for the PHEN/TPM groups were broad, indicating that the data were compatible with a wide range of possible values.

Multiple marketing withdrawals due to proarrhythmic concerns occurred in the United States, Canada, and the United Kingdom in the late 1980s to early 2000s. This primer reviews the clinical implications of a drug's identified proarrhythmic liability, the issues associated with these safety-related withdrawals, and the actions taken by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) and by regulatory agencies in terms of changing drug development practices and introducing new nonclinical and clinical tests to asses proarrhythmic liability. ICH Guidelines S7B and E14 were released in 2005. Since then, they have been adopted by many regional regulatory authorities and have guided nonclinical and clinical proarrhythmic cardiac safety assessments during drug development. While this regulatory paradigm has been successful in preventing drugs with unanticipated potential for inducing the rare but potentially fatal polymorphic ventricular arrhythmia torsade de pointes from entering the market, it has led to the termination of drug development programs for other potentially useful medicines because of isolated results from studies with limited predictive value. Research efforts are now exploring alternative approaches to better predict potential proarrhythmic liabilities. For example, in the domain of human electrocardiographic assessments, concentration-response modeling conducted during phase 1 clinical development has recently become an accepted alternate primary methodology to the ICH E14 "thorough QT/QTc" study for defining a drug's corrected QT interval prolongation liability under certain conditions. When a drug's therapeutic benefit is considered important at a public health level but there is also an identified proarrhythmic liability that may result from administration of the single drug in certain individuals and/or drug-drug interactions, marketing approval will be accompanied by appropriate directions in the drug's prescribing information. Health-care professionals in the fields of medicine and pharmacy need to consider the prescribing information in conjunction with individual patients' clinical characteristics and concomitant medications when prescribing and dispensing such drugs., (© 2018, The American College of Clinical Pharmacology.)

Background: There is no nonparenteral medication for the rapid termination of paroxysmal supraventricular tachycardia., Objectives: The purpose of this study was to assess the efficacy and safety of etripamil nasal spray, a short-acting calcium-channel blocker, for the rapid termination of paroxysmal supraventricular tachycardia (SVT)., Methods: This phase 2 study was performed during electrophysiological testing in patients with previously documented SVT who were induced into SVT prior to undergoing a catheter ablation. Patients in sustained SVT for 5 min received either placebo or 1 of 4 doses of active compound. The primary endpoint was the SVT conversion rate within 15 min of study drug administration. Secondary endpoints included time to conversion and adverse events., Results: One hundred four patients were dosed. Conversion rates from SVT to sinus rhythm were between 65% and 95% in the etripamil nasal spray groups and 35% in the placebo group; the differences were statistically significant (Pearson chi-square test) in the 3 highest active compound dose groups versus placebo. In patients who converted, the median time to conversion with etripamil was <3 min. Adverse events were mostly related to the intranasal route of administration or local irritation. Reductions in blood pressure occurred predominantly in the highest etripamil dose., Conclusions: Etripamil nasal spray rapidly terminated induced SVT with a high conversion rate. The safety and efficacy results of this study provide guidance for etripamil dose selection for future studies involving self-administration of this new intranasal calcium-channel blocker in a real-world setting for the termination of SVT. (Efficacy and Safety of Intranasal MSP-2017 [Etripamil] for the Conversion of PSVT to Sinus Rhythm [NODE-1]; NCT02296190)., (Copyright © 2018 Milestone Pharmaceuticals Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: The aim of this analysis was to investigate the potential for ulixertinib (BVD-523) to prolong cardiac repolarization. The mean prolongation of the corrected QT (QTc) interval was predicted at the mean maximum drug concentrations of the recommended phase 2 dose (RP2D; 600 mg BID) and of higher concentrations. In addition, the effect of ulixertinib on other quantitative ECG parameters was assessed., Methods: In a two-part, phase 1, open-label study in adults with advanced solid tumors, 105 patients [24 in Part 1 (dose escalation) and 81 in Part 2 (cohort expansion)] were included in a QT prolongation analysis. Electrocardiograms (ECGs) extracted from 12-lead Holter monitors, along with time-matched pharmacokinetic blood samples, were collected over 12 h on cycle 1 day 1 and cycle 1 day 15 and analyzed by a core ECG laboratory., Results: A small increase in heart rate was observed on both study days (up to 5.6 bpm on day 1 and up to 7 bpm on day 15). The estimated mean changes from baseline in the study-specific QTc interval (QTcSS), at the ulixertinib C max , were - 0.529 ms (90% CI - 6.621, 5.562) on day 1 and - 9.202 ms (90% CI - 22.505, 4.101) on day 15. The concentration: QTc regression slopes were mildly positive but not statistically significant [0.53 (90% CI - 1.343, 2.412) and 1.16 (90% CI - 1.732, 4.042) ms per µg/mL for days 1 and 15, respectively]. Ulixertinib had no meaningful effect on PR or QRS intervals., Conclusions: Ulixertinib administered to patients with solid tumors at clinically relevant doses has a low risk for QT/QTc prolongation or any other effects on ECG parameters., Registration: The study is registered at Clinicaltrials.gov (NCT01781429) and was sponsored by BioMed Valley Discoveries.

[This corrects the article DOI: 10.1371/journal.pone.0163619.].

The novel direct oral anticoagulants (NOACs) represent a major advance in oral anticoagulant therapy and are replacing vitamin K antagonists as the preferred options for many indications. Given in fixed doses without routine laboratory monitoring, they have been shown to be at least as effective in reducing thromboembolic stroke as dose-adjusted warfarin in phase 3 randomized trials and less likely to cause hemorrhagic stroke. Pharmacokinetic and/or pharmacodynamic subanalyses of the major NOAC trials in patients with atrial fibrillation have established relationships between clinical characteristics, and drug levels and/or pharmacodynamic responses with both efficacy and safety. Based on these analyses, pharmaceutical manufacturers and regulatory authorities have provided contraindications and dosing recommendations based on clinical characteristics that are associated with drug levels and/or pharmacodynamic responses, stroke reduction, and bleeding risk to optimize the risk-benefit profile of the NOACs in the real world. The current fixed-dosing strategy of NOACs has triggered discussions about the potential value of laboratory monitoring and dose adjustment in customizing drug exposure to further improve the safety and efficacy of the NOACs in patients with atrial fibrillation. As there is neither high-quality evidence nor consensus about the potential role of laboratory monitoring and dose adjustment for the NOACs, a Cardiac Research Safety Consortium "Think Tank" meeting was held at the American College of Cardiology Heart House in December 2015 to discussions these issues. This manuscript reports on the deliberations and the conclusions reached at that meeting., (Copyright © 2017. Published by Elsevier Inc.)

Thorough QT/QTc studies have become an integral part of early drug development programs, with major clinical and regulatory implications. This analysis expands on existing pharmacodynamic models of QT interval analysis by incorporating the influence of glycemic changes on the QT interval in a semimechanistic manner. A total of 21 healthy subjects enrolled in an open-label phase 1 pilot study and provided continuous electrocardiogram monitoring and plasma glucose and insulin concentrations associated with a 24-hour baseline assessment. The data revealed a transient decrease in QTc, with peak suppression occurring approximately 3 hours after the meal. A semimechanistic modeling approach was applied to evaluate temporal delays between meals and subsequent changes that might influence QT measurements. The food effect was incorporated into a model of heart rate dynamics, and additional delayed effects of the meal on QT were incorporated using a glucose-dependent hypothetical transit compartment. The final model helps to provide a foundation for the future design and analysis of QT studies that may be confounded by meals. This study has significant implications for QT study assessment following a meal or when a cohort is receiving a medication that influences postprandial glucose concentrations., (© 2017, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.)

Background: Macrolide antibiotics may cause QT prolongation., Objectives: To study the QT effect of a novel macrolide, solithromycin., Methods: This was a thorough QT study with a three-way crossover design performed in healthy male and female subjects to evaluate the ECG effects of a novel macrolide, solithromycin. Forty-eight subjects were randomized to receive 800 mg of intravenous (iv) solithromycin, 400 mg of oral moxifloxacin and placebo in three separate treatment periods. Continuous 12 lead ECGs were recorded at a pre-dose baseline and serially after drug administration for 24 h., Results: After the 40 min infusion of 800 mg of solithromycin, the geometric mean solithromycin peak plasma concentration (C max ) reached 5.9 (SD: 1.30) μg/mL. Solithromycin infusion caused a heart rate increase with a peak effect of 15 bpm immediately after the end of the infusion. The change-from-baseline QTcF (ΔQTcF) was similar after dosing with solithromycin and placebo and the resulting placebo-corrected ΔQTcF (ΔΔQTcF) for solithromycin was therefore small at all timepoints with a peak effect at 4 h of only 2.8 ms (upper bound of the 90% CI: 4.9 ms). Using a linear exposure-response model, a statistically significant, slightly negative slope of -0.86 ms per ng/mL (90% CI: -1.19 to -0.53; P = 0.0001) was observed with solithromycin. The study's ability to detect small QT changes was confirmed by the moxifloxacin response. Solithromycin did not have a clinically meaningful effect on the PR or QRS interval., Conclusions: The study demonstrated that solithromycin, unlike other macrolide antibiotics, does not cause QT prolongation., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Background: Drugs that prolong the heart rate corrected QT interval (QTc) on the electrocardiogram (ECG) by blocking the hERG potassium channel and also block inward currents (late sodium or L-type calcium) are not associated with torsade de pointes (e.g. ranolazine and verapamil). Thus, identifying ECG signs of late sodium current block could aid in the determination of proarrhythmic risk for new drugs. A new cardiac safety paradigm for drug development (the "CiPA" initiative) will involve the preclinical assessment of multiple human cardiac ion channels and ECG biomarkers are needed to determine if there are unexpected ion channel effects in humans., Methods and Results: In this study we assess the ability of eight ECG morphology biomarkers to detect late sodium current block in the presence of QTc prolongation by analyzing a clinical trial where a selective hERG potassium channel blocker (dofetilide) was administered alone and then in combination with two late sodium current blockers (lidocaine and mexiletine). We demonstrate that late sodium current block has the greatest effect on the heart-rate corrected J-Tpeak interval (J-Tpeakc), followed by QTc and then T-wave flatness. Furthermore, J-Tpeakc is the only biomarker that improves detection of the presence of late sodium current block compared to using QTc alone (AUC: 0.83 vs. 0.72 respectively, p<0.001)., Conclusions: Analysis of the J-Tpeakc interval can differentiate drug-induced multichannel block involving the late sodium current from selective hERG potassium channel block. Future methodologies assessing drug effects on cardiac ion channel currents on the ECG should use J-Tpeakc to detect the presence of late sodium current block., Trial Registration: NCT02308748 and NCT01873950., Competing Interests: PT Sager has consulting agreements with Biomedical Systems, Charles River, and iCardiac. The other authors report no conflicts. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

The Cardiac Safety Research Consortium (CSRC), a transparent, public-private partnership established in 2005 as a Critical Path Program and formalized in 2006 under a Memorandum of Understanding between the United States Food and Drug Administration and Duke University, is entering its second decade. Our continuing goal is to advance paradigms for more efficient regulatory science related to the cardiovascular safety of new therapeutics, both in the United States and globally, particularly where such safety questions add burden to innovative research and development. Operationally, CSRC brings together a broad base of stakeholders from academia, industry, and government agencies in a collaborative forum focused on identifying barriers and then creating novel solutions through shared data, expertise, and collaborative research. This white paper provides a brief overview of the Consortium's activities in its first decade and a context for some of our current activities and future directions. The growth and success of the CSRC have been primarily driven by members' active participation and the development of goodwill and trust throughout our membership, which have facilitated novel collaborations across traditionally competitive or contentious stakeholder boundaries. The continued expansion of our base of participating academicians, industry experts, and regulators will define the Consortium's success in our second decade. It is our hope that sharing our endeavors to date will stimulate additional participation in the CSRC and also provide a model for other groups starting to develop similar collaborative forums., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Patients with type 2 diabetes (T2D) have a substantial increased risk for cardiovascular (CV) disease and associated mortality than those without diabetes. Dulaglutide is a once-weekly glucagon-like peptide-1 receptor agonist that is approved for treatment of T2D., Methods: This meta-analysis evaluates the CV risk in patients with T2D treated with dulaglutide in 9 randomized safety and efficacy trials. Mean (median) treatment duration was 333 (358) days. Reported CV events were independently adjudicated by a treatment-blinded clinical endpoint committee. The primary measure was a 4-component major adverse CV event (4-component MACE) composite endpoint of death due to CV causes, nonfatal myocardial infarction (MI), nonfatal stroke, or hospitalization for unstable angina. Additional pre-specified endpoints included adjudicated coronary revascularizations, hospitalization for heart failure, and all-cause mortality. A Cox proportional hazards regression model (stratified by study) was used to estimate the hazard ratio (HR) and confidence interval (CI). Tests of treatment effects for the primary endpoint were conducted at a 2-sided alpha level of 0.0198 and a corresponding 98.02 % CI was calculated. Statistical heterogeneity between the strata (studies) was tested by including in the Cox model an interaction term between treatment and strata., Results: The analysis included 6010 randomized patients [dulaglutide: 3885; comparator therapy (active or placebo): 2125]; cumulative exposure to dulaglutide or comparator therapy was 3941 and 2223 patient-years, respectively. The demographic and baseline CV disease characteristics were similar across groups. Twenty-six (0.67 %) patients in the dulaglutide group versus 25 (1.18 %) in the comparator group experienced a primary 4-component MACE (HR 0.57; adjusted 98.02 % CI 0.30, 1.10). Results for the 3-component MACE (composite endpoint of death due to CV causes, nonfatal MI or stroke), 6-component MACE (composite endpoint of death due to CV causes, nonfatal MI or stroke, hospitalization for unstable angina or heart failure, or coronary revascularizations) and all-cause mortality were consistent with the primary analysis (HR < 1.0 for all)., Conclusions: These results suggest that dulaglutide does not increase the risk of major CV events in T2D patients. The ongoing CV outcomes study, Researching CV Events with a Weekly Incretin in Diabetes (REWIND), will further assess CV safety of dulaglutide.

Romidepsin is a histone deacetylase inhibitor approved by the FDA for the treatment of patients with cutaneous or peripheral T-cell lymphoma who have received prior systemic therapy. The objective of this analysis was to evaluate the potential QTc effects of romidepsin. Patients with advanced malignancy received 4-h infusions of 14 mg/m(2) romidepsin on days 1, 8, and 15 of a 28-day cycle. In cycle 2, a subset of patients received 1-h infusions of 8-12 mg/m(2) romidepsin. Patients were administered antiemetics before each romidepsin dose and electrolyte supplementation as needed. Electrocardiogram readings were performed prior to antiemetic administration, prior to romidepsin administration, and at specified time points over the subsequent 24 h. Romidepsin exposure and heart rate were also assessed. In the electrocardiogram-evaluable population, 26 patients received romidepsin at 14 mg/m(2) over 4 h. The maximum mean increases from the preantiemetic baseline for QTcF and heart rate were 10.1 msec (upper 90% CI, 14.5 msec) and 18.2 beats per minute, respectively. No patient in this study had an absolute QTcF value >450 msec and only one patient had an increase from the preantiemetic baseline of >60 msec. There was a mild reduction in the PR interval and no meaningful changes in the QRS interval. Despite the use of QT-prolonging antiemetics, treatment with romidepsin did not markedly prolong the QTc interval through 24 h. Increases in calculated QTc may have been exaggerated as a consequence of transient increases in heart rate., (© 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Sudden cardiac death is a common cause of death in patients with structural heart disease, genetic mutations, or acquired disorders affecting cardiac ion channels. A wide range of platforms exist to model and study disorders associated with sudden cardiac death. Human clinical studies are cumbersome and are thwarted by the extent of investigation that can be performed on human subjects. Animal models are limited by their degree of homology to human cardiac electrophysiology, including ion channel expression. Most commonly used cellular models are cellular transfection models, which are able to mimic the expression of a single-ion channel offering incomplete insight into changes of the action potential profile. Induced pluripotent stem cell-derived cardiomyocytes resemble, but are not identical, adult human cardiomyocytes and provide a new platform for studying arrhythmic disorders leading to sudden cardiac death. A variety of platforms exist to phenotype cellular models, including conventional and automated patch clamp, multielectrode array, and computational modeling. Induced pluripotent stem cell-derived cardiomyocytes have been used to study long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and other hereditary cardiac disorders. Although induced pluripotent stem cell-derived cardiomyocytes are distinct from adult cardiomyocytes, they provide a robust platform to advance the science and clinical care of sudden cardiac death., (© 2015 American Heart Association, Inc.)

This white paper provides a summary of presentations and discussions that were held at an Anticoagulant-Induced Bleeding and Reversal Agents Think Tank co-sponsored by the Cardiac Safety Research Consortium and the US Food and Drug Administration (FDA) at the FDA's White Oak Headquarters on April 22, 2014. Attention focused on a development pathway for reversal agents for the novel oral anticoagulants (NOACs). This is important because anticoagulation is still widely underused for stroke prevention in patients with atrial fibrillation. Undertreatment persists, although NOACs, in general, overcome some of the difficulties associated with anticoagulation provided by vitamin K antagonists. One reason for the lack of a wider uptake is the absence of NOAC reversal agents. As there are neither widely accepted academic and industry standards nor a definitive regulatory policy on the development of such reversal agents, this meeting provided a forum for leaders in the fields of cardiovascular clinical trials and cardiovascular safety to discuss the issues and develop recommendations. Attendees included representatives from pharmaceutical companies; regulatory agencies; end point adjudication specialist groups; contract research organizations; and active, academically based physicians. There was wide and solid consensus that NOACs overall offer improvements in convenience, efficacy, and safety compared with warfarin, even without reversal agents. Still, it was broadly accepted that it would be helpful to have reversal agents available for clinicians to use. Because it is not feasible to do definitive outcomes studies demonstrating a reversal agent's clinical benefits, it was felt that these agents could be approved for use in life-threatening bleeding situations if the molecules were well characterized preclinically, their pharmacodynamic and pharmacokinetic profiles were well understood, and showed no harmful adverse events in early human testing. There was also consensus that after such approval, efforts should be made to augment the available clinical information until such time as there is a body of evidence to demonstrate real-world clinical outcomes with the reversal agents. No recommendations were made for more generalized use of these agents in the setting of non-life-threatening situations. This article reflects the views of the authors and should not be construed to represent FDA's views or policies., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This White Paper provides a summary of presentations and discussions at a Cardiovascular Safety Outcome Trials Think Tank cosponsored by the Cardiac Safety Research Consortium, the US Food and Drug Administration, and the American College of Cardiology, held at American College of Cardiology's Heart House, Washington, DC, on February 19, 2014. Studies to assess cardiovascular (CV) risk of a new drug are sometimes requested by regulators to resolve ambiguous safety signals seen during its development or among other members of its class. Think Tank participants thought that important considerations in undertaking such studies were as follows: (1) plausibility-how likely it is that a possible signal indicating risk is real, based on strength of evidence, and/or whether a plausible mechanism of action for potential CV harm has been identified; (2) relevance-what relative and absolute CV risk would need to be excluded to determine that the drug had an acceptable benefit-to-risk balance for its use in the intended patient population; and (3) how plausibility and relevance influence the timing and approach to further safety assessment., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This white paper provides a summary of presentations and discussions at a cardiovascular (CV) end point adjudication think tank cosponsored by the Cardiac Safety Research Committee and the US Food and Drug Administration (FDA) that was convened at the FDA's White Oak headquarters on November 6, 2013. Attention was focused on the lack of clarity concerning the need for end point adjudication in both CV and non-CV trials: there is currently an absence of widely accepted academic or industry standards and a definitive regulatory policy on how best to structure and use clinical end point committees (CECs). This meeting therefore provided a forum for leaders in the fields of CV clinical trials and CV safety to develop a foundation of initial best practice recommendations for use in future CEC charters. Attendees included representatives from pharmaceutical companies, regulatory agencies, end point adjudication specialist groups, clinical research organizations, and active, academically based adjudicators. The manuscript presents recommendations from the think tank regarding when CV end point adjudication should be considered in trials conducted by cardiologists and by noncardiologists as well as detailing key issues in the composition of a CEC and its charter. In addition, it presents several recommended best practices for the establishment and operation of CECs. The science underlying CV event adjudication is evolving, and suggestions for additional areas of research will be needed to continue to advance this science. This manuscript does not constitute regulatory guidance., (Copyright © 2014 Elsevier Inc. All rights reserved.)

In December 2008, the US Food and Drug Administration (FDA) issued a guidance for industry requiring sponsors to demonstrate that a new antidiabetic therapy being developed to treat type 2 diabetes does not increase cardiovascular (CV) risk to an unacceptable extent. CV events reported during phase 2 and phase 3 trials should be prospectively and independently adjudicated. Before submission of a new drug application or biologics license application, sponsors should compare the incidence of major CV events occurring with the investigational agent versus the control group to show that the upper bound of the 2-sided 95% confidence interval (CI) for the estimated risk ratio is less than 1.8. If the CI includes 1.3, a postmarketing trial will be necessary to definitively show that the upper bound of the 95% CI for the estimated risk ratio is then less than 1.3. In 2012, the European Medicines Agency (EMA) issued an updated guideline on the clinical investigation of medicinal products in the treatment or prevention of diabetes mellitus that detailed its CV safety assessment requirements. Although similar to the FDA guidance, the EMA guideline does not prospectively define any pre- or postapproval risk margins. This expert perspective, prepared by members of the Cardiac Safety Research Consortium, discusses clinical development strategies, operational issues, and statistical methodological issues to satisfy the FDA's CV safety requirements, and, where appropriate, the EMA guideline. Actual case examples, where applicable, are presented.

Glucagon-like peptide-1 receptor agonists, used to treat type 2 diabetes mellitus, are associated with small reductions in systolic blood pressure (SBP) and increases in heart rate. However, findings based on clinic measurements do not adequately assess a drug's 24-hour pharmacodynamic profile. The effects of dulaglutide, a once-weekly glucagon-like peptide-1 receptor agonist, on BP and heart rate were investigated using ambulatory BP monitoring. Patients (n=755; 56±10 years; 81% white; 48% women), with type 2 diabetes mellitus, taking ≥1 oral antihyperglycemic medication, with a clinic BP between 90/60 and 140/90 mm Hg were randomized to dulaglutide (1.5 or 0.75 mg) or placebo subcutaneously for 26 weeks. Ambulatory BP monitoring was performed at baseline and at 4, 16, and 26 weeks. The primary end point was change from baseline to week 16 in mean 24-hour SBP, a tree gatekeeping strategy compared the effects of dulaglutide to placebo. Both doses of dulaglutide were noninferior to placebo for changes in 24-hour SBP and diastolic blood pressure, and dulaglutide 1.5 mg significantly reduced SBP (least squares mean difference [95% confidence interval]), -2.8 mm Hg [-4.6, -1.0]; P≤0.001). Dulaglutide 0.75 mg was noninferior to placebo (1.6 bpm; [0.3, 2.9]; P≤0.02) for 24-hour heart rate (least squares mean difference [95% confidence interval]), but dulaglutide 1.5 mg was not (2.8 bpm [1.5, 4.2]). Dulaglutide 1.5 mg was associated with a reduction in 24-hour SBP and an increase in 24-hour heart rate. The mechanisms responsible for the observed effects remain to be clarified., (© 2014 American Heart Association, Inc.)

Recent advances in electrocardiographic monitoring and waveform analysis have significantly improved the ability to detect drug-induced changes in cardiac repolarization manifested as changes in the QT/corrected QT interval. These advances have also improved the ability to detect drug-induced changes in cardiac conduction. This White Paper summarizes current opinion, reached by consensus among experts at the Cardiac Safety Research Consortium, on the assessment of electrocardiogram-based safety measurements of the PR and QRS intervals, representing atrioventricular and ventricular conduction, respectively, during drug development., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Continuous Holter recordings are often used in thorough QT studies (TQTS), with multiple 10-second electrocardiograms (ECGs) visually selected around predesignated time points. The authors hypothesized that computer-automated ECG selection would reduce within-subject variability, improve study data precision, and increase study power. Using the moxifloxacin and placebo arms of a Holter-based crossover TQTS, the authors compared interval duration measurements (IDMs) from manually selected to computer-selected ECGs. All IDMs were made with a fully automated computer algorithm. Moxifloxacin-induced changes in baseline- and placebo-subtracted QT intervals were similar for manual and computer ECG selection. Mean 90% confidence intervals were narrower, and within-subject variability by mixed-model covariance was lower for computer-selected than for manual-selected ECGs. Computer ECG selection reduced the number of subjects needed to achieve 80% power by 40% to 50% over manual. Computer ECG selection returns accurate ddQTcF values with less measurement variability than manual ECG selection by a variety of metrics. This results in increased study power and reduces the number of subjects needed to achieve desired power, which represents a significant potential source cost savings in clinical drug trials.

The ability to make informed benefit-risk assessments for potentially cardiotoxic new compounds is of considerable interest and importance at the public health, drug development, and individual patient levels. Cardiac imaging approaches in the evaluation of drug-induced myocardial dysfunction will likely play an increasing role. However, the optimal choice of myocardial imaging modality and the recommended frequency of monitoring are undefined. These decisions are complicated by the array of imaging techniques, which have varying sensitivities, specificities, availabilities, local expertise, safety, and costs, and by the variable time-course of tissue damage, functional myocardial depression, or recovery of function. This White Paper summarizes scientific discussions of members of the Cardiac Safety Research Consortium on the main factors to consider when selecting nonclinical and clinical cardiac function imaging techniques in drug development. We focus on 3 commonly used imaging modalities in the evaluation of cardiac function: echocardiography, magnetic resonance imaging, and radionuclide (nuclear) imaging and highlight areas for future research., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Background: Diagnosing obstructive coronary artery disease (CAD) in at-risk patients can be challenging and typically requires both noninvasive imaging methods and coronary angiography, the gold standard. Previous studies have suggested that peripheral blood gene expression can indicate the presence of CAD., Objective: To validate a previously developed 23-gene, expression-based classification test for diagnosis of obstructive CAD in nondiabetic patients., Design: Multicenter prospective trial with blood samples obtained before coronary angiography. (ClinicalTrials.gov registration number: NCT00500617) SETTING: 39 centers in the United States., Patients: An independent validation cohort of 526 nondiabetic patients with a clinical indication for coronary angiography., Measurements: Receiver-operating characteristic (ROC) analysis of classifier score measured by real-time polymerase chain reaction, additivity to clinical factors, and reclassification of patient disease likelihood versus disease status defined by quantitative coronary angiography. Obstructive CAD was defined as 50% or greater stenosis in 1 or more major coronary arteries by quantitative coronary angiography., Results: The area under the ROC curve (AUC) was 0.70 ± 0.02 (P < 0.001); the test added to clinical variables (Diamond-Forrester method) (AUC, 0.72 with the test vs. 0.66 without; P = 0.003) and added somewhat to an expanded clinical model (AUC, 0.745 with the test vs. 0.732 without; P = 0.089). The test improved net reclassification over both the Diamond-Forrester method and the expanded clinical model (P < 0.001). At a score threshold that corresponded to a 20% likelihood of obstructive CAD (14.75), the sensitivity and specificity were 85% and 43% (yielding a negative predictive value of 83% and a positive predictive value of 46%), with 33% of patient scores below this threshold., Limitation: Patients with chronic inflammatory disorders, elevated levels of leukocytes or cardiac protein markers, or diabetes were excluded., Conclusion: A noninvasive whole-blood test based on gene expression and demographic characteristics may be useful for assessing obstructive CAD in nondiabetic patients without known CAD., Primary Funding Source: CardioDx.

Electrocardiographic monitoring is an integral component of the clinical assessment of cardiac safety of all compounds in development. The International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use E14 guideline recommends a dedicated study to evaluate drug-induced effects on cardiac repolarization ("thorough QT/QTc study"). There has been limited published information on QT interval changes secondary to therapeutic proteins; however, in theory, biologic therapies may affect cardiac electrical activity either directly or indirectly. This article summarizes scientific discussions of members of the Cardiac Safety Research Consortium and includes possible approaches to consider for the clinical evaluation of drug-induced QT prolongation in development programs of therapeutic proteins., (Copyright © 2010 Mosby, Inc. All rights reserved.)

Decreasing C-reactive protein (CRP) in addition to decreasing low-density lipoprotein (LDL) cholesterol may further decrease coronary heart disease risk. The effects of rosuvastatin compared with atorvastatin in achieving a combined target of LDL cholesterol <70 mg/dl and CRP <2 mg/L in 509 patients with type 2 diabetes mellitus was evaluated. CRP decreased significantly versus baseline in both treatment groups. Significantly more patients treated with rosuvastatin achieved the combined end point of LDL cholesterol <70 mg/dl and CRP <2 mg/L compared with atorvastatin by the end of the study period (58% vs 37%; p <0.001 vs atorvastatin). In conclusion, CRP was effectively decreased in patients with type 2 diabetes receiving rosuvastatin or atorvastatin, whereas rosuvastatin decreased LDL cholesterol significantly more than atorvastatin.

To define the effect of short-term rosuvastatin treatment on the estimated glomerular filtration rate (eGFR), the database of controlled clinical trials in the Rosuvastatin Clinical Development Program was reviewed. Thirteen studies comprising 3,956 rosuvastatin-treated patients were selected based on a serum creatinine measurement at 6 or 8 weeks after initiation of rosuvastatin treatment, randomization to approved and marketed rosuvastatin doses (5 to 40 mg), and unchanged rosuvastatin dose from treatment initiation (baseline) through 6 to 8 weeks of treatment. eGFR was determined with the Modification of Diet in Renal Disease formula. eGFR significantly increased for each dose of rosuvastatin individually and for all doses combined compared with baseline (range +0.9 to +3.2 ml/min/1.73 m2). Further analysis of 5 blinded, placebo-controlled trials comprising 525 patients showed an increase in eGFR of +0.8 ml/min/1.73 m2 (95% confidence interval +0.1 to +1.5) for all rosuvastatin-treated patients, which was significantly different from baseline (p <0.04) and from a change of -1.5 ml/min/1.73 m2 in the placebo-treated patients (95% confidence interval -2.5 to -0.5, p <0.001). The increase in eGFR for rosuvastatin-treated patients was consistent across all major demographic and clinical subgroups of interest, including patients with baseline proteinuria, baseline eGFR <60 ml/min/1.73 m2, and in patients with hypertension and/or diabetes. In conclusion, these results are consistent with previous rosuvastatin studies that showed an upward trend in eGFR with long-term treatment (> or =96 weeks) and with the hypothesis that statins may have pleiotropic mechanisms of action that include beneficial renal effects.

Proarrhythmias due to drug-induced QT prolongation are the second most common cause for drug withdrawal and have caused increasing concern. Two new International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines were recently endorsed in which nonclinical (S7B) and clinical (E14) methodologies are discussed and guidance is given to the industry. This commentary describes the key components of the E14 document, the impact of nonclinical testing on the clinical program, the thorough QT study, and the impact of its result on late-stage development. The studies described in S7B and E14 will contribute to a better understanding of the link between nonclinical assays and QT prolongation in humans. Differences in interpretation among individual regulators in the major regions with respect to measures proposed in the E14 guideline might impact regional regulatory decisions. These differences include the value of nonclinical assays for the subsequent clinical testing and how predictive a negative thorough QT study result is for proarrhythmic risk in patients.

The lipid-modifying effects of statin therapy in hypercholesterolemic African-Americans have not been well characterized. This study compared the efficacy and safety of rosuvastatin and atorvastatin treatment for 6 weeks in hypercholesterolemic African-American adults. In the African American Rosuvastatin Investigation of Efficacy and Safety (ARIES) trial (4522US/0002), 774 adult African-Americans with low-density lipoprotein cholesterol > or = 160 and < or = 300 mg/dl and triglycerides < 400 mg/dl were randomized to receive open-label rosuvastatin 10 or 20 mg or atorvastatin 10 or 20 mg for 6 weeks. At week 6, significantly greater reductions in low-density lipoprotein cholesterol, total cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B concentrations, as well as lipoprotein and apolipoprotein ratios, were seen with rosuvastatin versus milligram-equivalent atorvastatin doses (analysis of variance with Bonferroni-adjusted critical p < 0.017 for all comparisons). Rosuvastatin 10 mg also increased high-density lipoprotein cholesterol significantly more than atorvastatin 20 mg (p < 0.017). Although statistical comparisons were not performed, larger proportions of rosuvastatin-treated patients than atorvastatin-treated patients achieved National Cholesterol Education Program Adult Treatment Panel III low-density lipoprotein cholesterol goals. The median high-sensitivity C-reactive protein levels were significantly reduced statistically from baseline with rosuvastatin 20 mg and atorvastatin 20 mg among all patients and with rosuvastatin 10 and 20 mg and atorvastatin 20 mg in those patients with a baseline C-reactive protein level > 2.0 mg/L. The 2 study medications were well tolerated during the 6-week study period. In conclusion, rosuvastatin 10 and 20 mg improved the overall lipid profile of hypercholesterolemic African-Americans better than did milligram-equivalent doses of atorvastatin.

Objective: This study assessed the effect of coadministration of ezetimibe and simvastatin on high sensitivity C-reactive protein (hs-CRP) in a large subject cohort (N=1089)., Methods: Data were combined from two nearly identical prospective trials. After dietary stabilization, washout period, and placebo lead-in period, patients with baseline low-density lipoprotein cholesterol (LDL-C) > or =3.75-6.50 mmol/l and triglycerides (TG) < or =4.0 mmol/l were randomized to one of the following daily treatments for 12 weeks: ezetimibe 10 mg; simvastatin monotherapy (10, 20, 40, or 80 mg); ezetimibe 10mg plus simvastatin (10, 20, 40, or 80 mg); or placebo. The primary analysis was the percent change in hs-CRP for the pooled ezetimibe plus simvastatin versus simvastatin monotherapy cohorts., Results: Ezetimibe coadministered with simvastatin more than doubled the hs-CRP reduction compared to simvastatin monotherapy (-33.3% versus -14.3%, p<0.01). At each individual simvastatin dose level, coadministration therapy exerted significant further incremental hs-CRP reductions compared to simvastatin monotherapy. Similar hs-CRP reductions with coadministered ezetimibe and simvastatin were observed in the major subgroups examined (coronary heart disease, gender, age, baseline LDL-C, and body mass index)., Conclusion: In this large subject cohort, ezetimibe coadministered with simvastatin significantly reduced hs-CRP, suggesting a possible additional anti-inflammatory/anti-atherosclerotic action of combination therapy compared to simvastatin monotherapy.

Background: Lipid lowering through statin therapy significantly reduces the risk of cardiovascular events. The ENHANCE study is an international 2-year, randomized, double-blind, controlled trial designed to test the hypothesis that treatment of hypercholesterolemia by use of 2 complementary agents, ezetimibe (a specific cholesterol absorption inhibitor) and simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor), will result in larger beneficial effects on carotid artery intima-media thickness (CA IMT) than simvastatin monotherapy., Methods: The study will recruit 725 men and women with heterozygous familial hypercholesterolemia. After a placebo washout period, participants are randomized to receive daily administration of either simvastatin 80 mg and ezetimibe 10 mg or simvastatin 80 mg and placebo. The ENHANCE trial uses novel state-of-the-art single-frame digital image acquisition and rigorous quality assurance and control., Results: The primary end point is mean change from baseline to 2 years in CA IMT, using composite measures from the right and left far wall common carotid artery, carotid bulb, and internal carotid artery. Secondary end points include (1) the proportion of participants who exhibit reductions in CA IMT, (2) the change in maximum far wall IMT, (3) the proportion of participants who develop new carotid artery plaques, and (4) the changes in carotid plus common femoral artery IMT., Conclusions: This study addresses the question of whether a regimen that uses drugs with different mechanisms of action will be of further benefit in terms of atherosclerosis reduction compared to statin monotherapy.

This study assessed the effect of ezetimibe coadministered with simvastatin on high-sensitivity C-reactive protein (hs-CRP) in patients with primary hypercholesterolemia. After dietary stabilization, a 2- to 12-week washout period, and a 4-week, single-blind, placebo lead-in period, patients with baseline low-density lipoprotein cholesterol > or =145 and < or =250 mg/dl and triglycerides < or =350 mg/dl were randomized to one of these daily treatments for 12 consecutive weeks: ezetimibe 10 mg; simvastatin monotherapy (10, 20, 40, or 80 mg); ezetimibe 10 mg plus simvastatin (10, 20, 40, or 80 mg); or placebo. The primary analysis was the change in hs-CRP for the pooled ezetimibe plus simvastatin versus simvastatin monotherapy groups. Ezetimibe plus simvastatin significantly reduced median hs-CRP levels compared with simvastatin monotherapy (-34.8% vs -18.2%, p<0.01), and incremental reductions were observed at each simvastatin dose level. Combination therapy-induced significant changes in individual lipid parameters did not explain the observed decreases in hs-CRP. Thus, ezetimibe coadministered with simvastatin resulted in significant incremental decreases in hs-CRP, possibly consistent with an additional anti-inflammatory effect compared with simvastatin monotherapy.

Background: Despite the established efficacy of statins, many patients do not achieve recommended LDL cholesterol (LDL-C) goals. Contributing factors may be inadequate dosing, increased risk for adverse effects with high-dose monotherapy, and increased potential for intolerance and adverse effects with combinations of available agents., Methods and Results: In a double-blind study, 628 patients with baseline LDL-C 145 to 250 mg/dL and triglycerides < or =350 mg/dL were randomly assigned to receive 1 of the following for 12 weeks: ezetimibe (10 mg/d); atorvastatin (10, 20, 40, or 80 mg/d); ezetimibe (10 mg) plus atorvastatin (10, 20, 40, or 80 mg/d); or placebo. The primary efficacy end point was percentage reduction in LDL-C for pooled ezetimibe plus atorvastatin versus pooled atorvastatin treatment groups. Ezetimibe plus atorvastatin significantly improved LDL-C, HDL cholesterol (HDL-C), triglycerides, total cholesterol:HDL-C, and high-sensitivity C-reactive protein (hs-CRP) compared with atorvastatin alone (P<0.01). Coadministration of ezetimibe provided a significant additional 12% LDL-C reduction, 3% HDL-C increase, 8% triglyceride reduction, and 10% hs-CRP reduction versus atorvastatin alone. Ezetimibe plus atorvastatin provided LDL-C reductions of 50% to 60%, triglyceride reductions of 30% to 40%, and HDL-C increases of 5% to 9%, depending on atorvastatin dose. LDL-C reductions with ezetimibe plus 10 mg atorvastatin (50%) and 80 mg atorvastatin alone (51%) were similar., Conclusions: Ezetimibe plus atorvastatin was well tolerated, with a safety profile similar to atorvastatin alone and to placebo. When coadministered with atorvastatin, ezetimibe provided significant incremental reductions in LDL-C and triglycerides and increases in HDL-C. Coadministration of ezetimibe and atorvastatin offers a well-tolerated and highly efficacious new treatment option for patients with hypercholesterolemia.