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The potential for unintended drug induced changes in cardiac contractility is a major concern in medicines development. Whilst direct left ventricular pressure (LVP) measurement is the gold standard for measuring cardiac contractility in vivo, it is resource intensive and poses a welfare burden on research animals. In contrast, arterial blood pressure (BP) measurement has fewer challenges. Symmetric Projection Attractor Reconstruction (SPAR) is a signal processing technique which transforms physiological time-series signals into a corresponding visual image ('attractor'), amplifying morphology changes within physiological waveforms. It was hypothesized that SPAR analysis of BP signals would provide a surrogate measure of cardiac contractility by specifically amplifying the maximum slope of the systolic upstroke. BP (abdominal aorta) signals obtained from beagle dogs, treated with positive and negative inotropes, were retrospectively analysed to identify signal features that correlated with the maximum upslope of the LVP signal from simultaneously acquired LVP recordings. SPAR transformation of BP signals quantified drug induced changes in the maximum slope of the systolic upstroke. We identified key SPAR metrics that provided >0.8 correlation with the LVP maximum upslope, outperforming the BP systolic upstroke alone. This was observed for all 4 different drugs, doses and time points evaluated across studies. Thus, we conclude that the SPAR measures derived from the BP signal could be used as a first pass in vivo screen to flag any risk of drug induced changes in cardiac contractility during the conduct of non-clinical medicines development, potentially reducing or replacing the need to perform direct left ventricular measurements., Competing Interests: Declaration of competing interest Philip Aston, Mark Christie and Manasi Nandi have a patent, WO2015121679A1, “Delay coordinate analysis of periodic data,” which covers the foundations of the Symmetric Projection Attractor Reconstruction (SPAR) method used in this paper. None of the other authors have any conflicts of interest, other than their employment in commercial pharmaceutical companies, academic institutions, or contract research organizations (CROs). No information is presented that advocates for or promotes commercial products from any organization., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Oligonucleotide therapeutics (ONTs) represent a new modality with unique pharmacological and chemical properties that modulate gene expression with a high degree of target specificity mediated by complementary Watson-Crick base pair hybridization. To date, the proarrhythmic assessment of ONTs has been influenced by International Conference on Harmonization (ICH) E14 and S7B guidance. To document current hERG/QTc evaluation practices, we reviewed US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) Approval Packages (source: PharmaPendium.com) and collated preclinical and clinical studies for 17 marketed ONTs. In addition, clinical QTc data from 12 investigational ONTs were obtained from the literature. Of the marketed ONTs, eight were tested in the hERG assay with no inhibitory effect identified at the top concentration (range: 34-3,000 μM) tested. Fourteen of the ONTs were evaluated in nonhuman primate cardiovascular studies with 11 of them in dedicated telemetry studies. No effect on QTc intervals were observed (at high exposure multiples) in all studies. Clinically, four ONTs were evaluated in TQT studies; an additional six ONTs were assessed by concentration-QTc interval analysis, and six by routine safety electrocardiogram monitoring. None of the clinical studies identified a QTc prolongation risk; the same was true for the 12 investigational ONTs. A search of the FDA Adverse Event Database indicated no association between approved ONTs and proarrhythmias. Overall, the collective weight of evidence from 29 ONTs demonstrate no clinical proarrhythmic risk based on data obtained from ICH S7B/E14 studies. Thus, new ONTs may benefit from reduced testing strategies because they have no proarrhythmic risk, a similar cardiac safety profile as monoclonal antibodies, proteins, and peptides., (© 2024 The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Competing Interests: Declaration of competing interest None of the authors has any conflicts of interest, other than their employment in commercial biopharmaceutical companies or contract research organizations (CROs). No information is presented in this paper that advocates for or promotes commercial products from any of our organizations.

Background: Metrology plays a crucial role in small healthcare service businesses to ensure the quality of products and services. While legal metrology in healthcare exists in some regions, it lacks harmonization. In other countries, there is limited presence of metrology in medical and biomedical engineering. We aimed to evaluate the implementation of metrological assurance systems for medical devices in Latin America., Methods: A systematic review was conducted following PRISMA 2020 guidelines and registered with PROSPERO (CRD42022359284). Searches were performed across 13 databases from October 30th to November 3rd, 2022. The search equation was "(((quality assurance) AND (metrology)) AND (medical devices))." A total of 7,789 documents were identified, of which only 16 met the inclusion criteria., Results: The majority of studies (75%) were conducted in Colombia, with a significant portion being undergraduate theses. The primary normative references used in the analyzed studies were ISO 10012 and ISO 17025, with the majority (68.75%) relying on national legislation for their approach. One study in Colombia referenced eight standards, and one in Brazil analyzed user involvement in medical device management. Among the included studies, 56.25% were conducted in healthcare institutions, mainly clinics. Most studies provided implementation guidelines, with ISO 10012 being prominent, alongside ISO 17025, which implicitly addresses ISO 9001 elements. Global bias was low across all studies., Conclusion: Our results underscore the importance of metrological assurance in managing medical devices in Latin America. The utilization of international standards and national legislation illustrates the diverse approaches adopted by different institutions. Future research should focus on optimizing metrological practices to enhance quality and safety in healthcare., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Farfán-Vargas, Espinoza-Morriberon, Moya-Salazar, Contreras-Pulache and Moya-Salazar.)

Understanding translation from preclinical observations to clinical findings is important for evaluating the efficacy and safety of novel compounds. Of relevance to cardiac safety is profiling drug effects on cardiomyocyte (CM) sarcomere shortening and intracellular Ca 2+ dynamics. Although CM from different animal species have been used to assess such effects, primary human CM isolated from human organ donor heart represent an ideal non-animal alternative approach. We performed a study to evaluate primary human CM and have them compared to freshly isolated dog cardiomyocytes for their basic function and responses to positive inotropes with well-known mechanisms. Our data showed that simultaneous assessment of sarcomere shortening and Ca 2+ -transient can be performed with both myocytes using the IonOptix system. Amplitude of sarcomere shortening and Ca 2+ -transient (CaT) were significantly higher in dog compared to human CM in the basic condition (absence of treatment), while longer duration of sarcomere shortening and CaT were observed in human cells. We observed that human and dog CMs have similar pharmacological responses to five inotropes with different mechanisms, including dobutamine and isoproterenol (β-adrenergic stimulation), milrinone (PDE3 inhibition), pimobendan and levosimendan (increase of Ca 2+ sensitization as well as PDE3 inhibition). In conclusion, our study suggests that myocytes obtained from both human donor hearts and dog hearts can be used to simultaneously assess drug-induced effects on sarcomere shortening and CaT using the IonOptix platform., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The ICH E14/S7B Questions and Answers (Q&As) guideline introduces the concept of a "double negative" nonclinical scenario (negative hERG assay and negative in vivo QTc study) to demonstrate that a drug does not produce a clinically relevant QT prolongation (i.e., no QT liability). This nonclinical "double negative" data package, along with negative Phase 1 clinical QTc data, may be sufficient to substitute for a clinical Thorough QT (TQT) study in some specific cases. While standalone GLP in vivo cardiovascular studies in non-rodent species are standard practice during nonclinical drug development for small molecule programs, a variety of approaches to the design, conduct, analysis and interpretation are utilized across pharmaceutical companies and contract research organizations (CROs) that may, in some cases, negatively impact the stringent sensitivity needed to fulfill the new Q&As. Subject matter experts from both Pharma and CROs have collaborated to recommend best practices for more robust nonclinical cardiovascular telemetry studies in non-rodent species, with input from clinical and regulatory experts. The aim was to increase consistency and harmonization across the industry and to ensure delivery of high quality nonclinical QTc data to meet the proposed sensitivities defined within the revised ICH E14/S7B Q&As guideline (Q&As 5.1 and 6.1). The detailed best practice recommendations presented here cover the design and execution of the safety pharmacology cardiovascular study, including optimal methods for acquiring, analyzing, reporting, and interpreting the resulting QTc and pharmacokinetic data to allow for direct comparison to clinical exposures and assessment of safety margin for QTc prolongation., Competing Interests: Declaration of Competing Interest All authors are employed by pharmaceutical companies or contract research organizations., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Adverse cardiovascular events that arise in patients with established cardiovascular disease have prompted researchers to seek variables that can help estimate residual cardiovascular risk and aid in its reduction. In Latin-America, there is limited data assessing this type of risk., Objective: Estimate residual cardiovascular risk in ambulatory patients diagnosed with Chronic Coronary Syndrome (CCS) using the SMART-Score scale seen at five clinics in Nicaragua; determine the prevalence of patients that achieve a serum LDL level of <55 mg/dL; and describe the use of statins in these patients., Methods: A total of 145 participants previously diagnosed with CCS seen regularly in ambulatory visits were enrolled. A survey was completed, including epidemiological variables that allowed the calculation of a SMART score. Data analysis was conducted using SPSS version 21.0., Results: A 46.2% of participants were male, the average age was 68.7 years (11.4 SD), 91% had hypertension, 80.7% had a BMI ≥25. Under the SMART Score risk classification per Dorresteijn et al. the following risk distribution was found: 2.8% low, 31% moderate, 20% high, 13.1% very high and 33.1% extremely high. Per the risk classification of Kaasenbrood et al., 2.8% were in the 0-9% group, 31% in the 10-19%, 20% in 20-29% and 46.2% were in the ≥30% group. A 64.8% did not meet LDL goals., Conclusion: There is an inadequate control of cLDL levels in patients with CCS, and the appropriate available therapeutic resources aren't being utilized. It is important to achieve a proper control of lipid levels in order to improve cardiovascular outcomes, despite currently being far from these goals., Competing Interests: No conflicts of interest to declare., (© 2023 The Authors.)

Recent updates and modifications to the clinical ICH E14 and nonclinical ICH S7B guidelines, which both relate to the evaluation of drug-induced delayed repolarization risk, provide an opportunity for nonclinical in vivo electrocardiographic (ECG) data to directly influence clinical strategies, interpretation, regulatory decision-making and product labeling. This opportunity can be leveraged with more robust nonclinical in vivo QTc datasets based upon consensus standardized protocols and experimental best practices that reduce variability and optimize QTc signal detection, i.e., demonstrate assay sensitivity. The immediate opportunity for such nonclinical studies is when adequate clinical exposures (e.g., supratherapeutic) cannot be safely achieved, or other factors limit the robustness of the clinical QTc evaluation, e.g., the ICH E14 Q5.1 and Q6.1 scenarios. This position paper discusses the regulatory historical evolution and processes leading to this opportunity and details the expectations of future nonclinical in vivo QTc studies of new drug candidates. The conduct of in vivo QTc assays that are consistently designed, executed and analyzed will lead to confident interpretation, and increase their value for clinical QTc risk assessment. Lastly, this paper provides the rationale and basis for our companion article which describes technical details on in vivo QTc best practices and recommendations to achieve the goals of the new ICH E14/S7B Q&As, see Rossman et al., 2023 (this journal)., Competing Interests: Declaration of Competing Interest All authors are employed by pharmaceutical companies or contract research organizations., (Copyright © 2023 Amgen, Inc. Published by Elsevier Inc. All rights reserved.)

In accord with International Conference on Harmonization S7B guidelines, an in vitro human ether-a-go-go-related gene (hERG) assay is one component of an integrated risk assessment for delayed ventricular repolarization. Function of hERG could be affected by direct (acute) mechanisms, or by indirect (chronic) mechanisms. Some approved oligonucleotide therapeutics had submitted hERG data to regulatory agents, which were all collected with the same protocol used for small-molecule testing (incubation time <20 min; acute), however, oligonucleotides have unique mechanisms and time courses of action (indirect). To reframe the hERG testing strategy for silencing RNA (siRNA), an investigation was performed to assess the time course for siRNA-mediated inhibition of hERG function and gene expression. Commercially available siRNAs of hERG were evaluated in a stable hERG-expressed cell line by whole-cell voltage clamp using automated electrophysiology and polymerase chain reaction. In the acute hERG study, no effects were observed after treatment with 100 nM siRNA for 20 min. The chronic effects of 100 nM siRNAs on hERG function were evaluated and recorded over 8-48 h following transfection. At 8 h there was no significant effect, whereas 77% reduction was observed at 48 h. Measurement of hERG mRNA levels demonstrated a 79% and 93% decrease of hERG mRNA at 8 and 48 h, respectively, consistent with inhibition of hERG transcription. The results indicate that an anti-hERG siRNA requires a long exposure time (48 h) in the hERG assay to produce a maximal reduction in hERG current; short exposures (20 min-8 h) had no effect. These findings imply that off-target profiling of novel oligonucleotides could benefit from using hERG protocol with long incubation times to de-risk potential off-target (indirect) effects on the hERG channel. This hERG assay modification may be important to consider if the findings are used to support an integrated nonclinical-clinical risk assessment for QTc (the duration of the QT interval adjusted for heart rate) prolongation.

In prior clinical studies, levocetirizine (LEVO) has demonstrated no effect on ventricular repolarization (QTc intervals), therefore it is a relevant negative control to assess in nonclinical assays to define low proarrhythmic risk. LEVO was tested in beagle dog and cynomolgus monkey (nonhuman primate [NHP]) telemetry models to understand the nonclinical-clinical translation of this negative control. One oral dose of vehicle, LEVO (10 mg/kg/species) or moxifloxacin (MOXI; 30 mg/kg/dog; 80 mg/kg/NHP) was administered to instrumented animals (N = 8/species) using a cross-over dosing design; MOXI was the in-study positive control. Corrected QT interval values (QTcI) were calculated using an individual animal correction factor. Blood samples were taken for drug exposure during telemetry and for pharmacokinetic (PK) analysis (same animals; different day) for exposure-response (C-QTc) modeling. Statistical analysis of QTc-by-timepoint data showed that LEVO treatment was consistent with vehicle, thus no effect on ventricular repolarization was observed over 24 h in both species. PK analysis indicated that LEVO-maximum concentration levels in dogs (range: 12,300-20,100 ng/ml) and NHPs (range: 4090-12,700 ng/ml) were ≥4-fold higher than supratherapeutic drug levels in clinical QTc studies. Slope analysis values in dogs (0.00019 ms/ng/ml) and NHPs (0.00016 ms/ng/ml) were similar to the human C-QTc relationship and indicated no relationship between QTc intervals and plasma levels of LEVO. MOXI treatment caused QTc interval prolongation (dog: 18 ms; NHP: 29 ms). The characterization of LEVO in these non-rodent telemetry studies further demonstrates the value and impact of the in vivo QTc assay to define a "no QTc effect" profile and support clinical safety assessment., (© 2022 Amgen, Inc. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

The content of this article derives from a Health and Environmental Sciences Institute (HESI) consortium with a focus to improve cardiac safety during drug development. A detailed literature review was conducted to evaluate the concordance between nonclinical repolarization assays and the clinical thorough QT (TQT) study. Food and Drug Administration and HESI developed a joint database of nonclinical and clinical data, and a retrospective analysis of 150 anonymized drug candidates was reviewed to compare the performance of 3 standard nonclinical assays with clinical TQT study findings as well as investigate mechanism(s) potentially responsible for apparent discrepancies identified. The nonclinical assays were functional (IKr) current block (Human ether-a-go-go related gene), action potential duration, and corrected QT interval in animals (in vivo corrected QT). Although these nonclinical assays demonstrated good specificity for predicting negative clinical QT prolongation, they had relatively poor sensitivity for predicting positive clinical QT prolongation. After review, 28 discordant TQT-positive drugs were identified. This article provides an overview of direct and indirect mechanisms responsible for QT prolongation and theoretical reasons for lack of concordance between clinical TQT studies and nonclinical assays. We examine 6 specific and discordant TQT-positive drugs as case examples. These were derived from the unique HESI/Food and Drug Administration database. We would like to emphasize some reasons for discordant data including, insufficient or inadequate nonclinical data, effects of the drug on other cardiac ion channels, and indirect and/or nonelectrophysiological effects of drugs, including altered heart rate. We also outline best practices that were developed based upon our evaluation., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society of Toxicology.)

The in vivo correct QT (QTc) assay is used by the pharmaceutical industry to characterize the potential for delayed ventricular repolarization and is a core safety assay mentioned in International Conference on Harmonization (ICH) S7B guideline. The typical telemetry study involves a dose-response analysis of QTc intervals over time using a crossover (CO) design. This method has proven utility but does not include direct integration of pharmacokinetic (PK) data. An alternative approach has been validated and is used routinely in the clinical setting that pairs pharmacodynamic (PD) responses with PK exposure (e.g., concentration-QTc (C-QTc) analysis. The goal of our paper was to compare the QTc sensitivity of two experimental approaches in the conscious dog and non-human primate (NHP) QTc assays. For timepoint analysis, a conventional design using eight animals (8 × 4 CO) to detect moxifloxacin-induced QTc prolongation was compared to a PK/PD design in a subset (N = 4) of the same animals. The findings demonstrate that both approaches are equally sensitive in detecting threshold QTc prolongation on the order of 10 ms. Both QTc models demonstrated linearity in the QTc prolongation response to moxifloxacin dose escalation (6 to 46 ms). Further, comparison with human QTc findings with moxifloxacin showed agreement and consistent translation across the three species: C-QTc slope values were 0.7- (dog) and 1.2- (NHP) fold of the composite human value. In conclusion, our data show that dog and NHP QTc telemetry with an integrated PK arm (C-QTc) has the potential to supplement clinical evaluation and improve integrated QTc risk assessment., (© 2021 Amgen Inc. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Introduction: Cardioplegic solutions were first developed to preserve heart function during cardiac surgeries and heart transplants but have application in the nonclinical setting. Due to lack of lab space in the vivarium, cardioplegic solution was used to conserve cardiac function for ex-vivo studies performed in a separate building. All studies in this report were conducted with isolated female rabbit hearts (IRHs) via retrograde perfusion using the Langendorff apparatus to investigate if cardioplegia usage affects cardiac function., Methods: Cardioplegia was achieved with a hyperkalemia (27 mM KCL) solution kept at 4 °C. Cardiac function was assessed by measuring ECG parameters, left ventricular contractility, and coronary flow under constant perfusion pressure. IRHs were cannulated with Krebs Henseleit buffer (KH) either fresh or after cardioplegic solution storage (C-IRH). Three comparisons were performed with and without cardioplegia; (i) direct side-by side studies of cardiac function; (ii) pharmacological responses to typical ion channels blockers, dofetilide, flecainide, and diltiazem; (iii) retrospective evaluation of cardiac functions in a large sample of hearts., Results: In the side-by-side comparisons, cardioplegia-stored IRHs (C-IRH; storage time 90 min) had similar electrocardiographic (ECG) and hemodynamic parameters to fresh-cannulated hearts with KH buffer (KH-IRH). In addition, responses to dofetilide, flecainide, and diltiazem, were similar for C-IRH and KH-IRH hearts. Over the years (2006-2011), baseline data was collected from 79 hearts without cardioplegia and 100 hearts with cardioplegia (C-IRH; storage time 15 min), which showed no meaningful differences in a retrospective analysis., Discussion: Cardiac function was preserved after cardioplegic treatment, however, coronary flow rates were decreased (-19.3%) in C-IRH hearts which indicated an altered coronary vascular tone. In conclusion, storage in cardioplegic solution preserves rabbit cardiac function, a practice that enables heart tissues to be collected at one site (e.g., vivarium) and transported to a laboratory in a separate location., Competing Interests: Declaration of Funding and Competing Interest Amgen Inc. provided study funding. All authors are employees and shareholders of Amgen Inc., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The concept of chemical agents having properties that confer potential hazard called key characteristics (KCs) was first developed to identify carcinogenic hazards. Identification of KCs of cardiovascular (CV) toxicants could facilitate the systematic assessment of CV hazards and understanding of assay and data gaps associated with current approaches., Objectives: We sought to develop a consensus-based synthesis of scientific evidence on the KCs of chemical and nonchemical agents known to cause CV toxicity along with methods to measure them., Methods: An expert working group was convened to discuss mechanisms associated with CV toxicity., Results: The group identified 12 KCs of CV toxicants, defined as exogenous agents that adversely interfere with function of the CV system. The KCs were organized into those primarily affecting cardiac tissue (numbers 1-4 below), the vascular system (5-7), or both (8-12), as follows: 1) impairs regulation of cardiac excitability, 2) impairs cardiac contractility and relaxation, 3) induces cardiomyocyte injury and death, 4) induces proliferation of valve stroma, 5) impacts endothelial and vascular function, 6) alters hemostasis, 7) causes dyslipidemia, 8) impairs mitochondrial function, 9) modifies autonomic nervous system activity, 10) induces oxidative stress, 11) causes inflammation, and 12) alters hormone signaling., Discussion: These 12 KCs can be used to help identify pharmaceuticals and environmental pollutants as CV toxicants, as well as to better understand the mechanistic underpinnings of their toxicity. For example, evidence exists that fine particulate matter [PM ≤ 2.5 μ m in aerodynamic diameter ( PM 2.5 )] air pollution, arsenic, anthracycline drugs, and other exogenous chemicals possess one or more of the described KCs. In conclusion, the KCs could be used to identify potential CV toxicants and to define a set of test methods to evaluate CV toxicity in a more comprehensive and standardized manner than current approaches. https://doi.org/10.1289/EHP9321.

Omecamtiv mecarbil (OM) is a myosin activator (myotrope), developed as a potential therapeutic agent for heart failure with reduced ejection fraction. To characterize the potential pro-arrhythmic risk of this novel sarcomere activator, we evaluated OM in a series of International Conference on Harmonization S7B core and follow-up assays, including an in silico action potential (AP) model. OM was tested in: (i) hERG, Nav1.5 peak, and Cav1.2 channel assays; (ii) in silico computation in a human ventricular AP (hVAP) population model; (iii) AP recordings in canine cardiac Purkinje fibers (PF); and (iv) electrocardiography analysis in isolated rabbit hearts (IRHs). OM had low potency in the hERG (half-maximal inhibitory concentration [IC 50 ] = 125.5 µM) and Nav1.5 and Cav1.2 assays (IC 50  > 300 µM). These potency values were used as inputs to investigate the occurrence of repolarization abnormalities (biomarkers of pro-arrhythmia) in an hVAP model over a wide range of OM concentrations. The outcome of hVAP analysis indicated low pro-arrhythmia risk at OM concentration up to 30 µM (100-fold the effective free therapeutic plasma concentration). In the isolated canine PF assay, OM shortened AP duration (APD) 60 and APD 90 significantly from 3 to 30 µM. In perfused IRH, ventricular repolarization (corrected QT and corrected JT intervals) was decreased significantly at greater than or equal to 1 µM OM. In summary, the comprehensive proarrhythmic assessment in human and non-rodent cardiac models provided data indicative that OM did not delay ventricular repolarization at therapeutic relevant concentrations, consistent with clinical findings., (© 2021 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

The ICH S7B guideline describes the requirement to conduct an in vitro I Kr (hERG) and in vivo QTc assay for human risk assessment of new drug products, but the guidance is devoid of recommendations on study execution or quality. In the absence of standard practice, multiple study designs and experimental approaches have been utilized, especially with the nonclinical QTc assay. Since 2009, our approach to the in vivo QTc assay has been consistent for small molecules and yields reproducible and sensitive levels for QTc signal detection. Our database and experience indicate that nonrodent telemetry studies can achieve high sensitivity and a calculated metric of study power can be used to indicate study quality. Using a retrospective statistical power analysis of multiple studies (n = 14 dog; n = 6 NHP), the detection sensitivity for a specific study design (N = 8; double Latin square cross-over) was determined. The output of the power analysis is the minimal detectable effect at 80% power and a 95% probability level. The design provided an average sensitivity to detect a 4.7 (2.0%) and 6.5 (1.9%) msec QTcI change in dog and NHP, respectively. These findings suggest that this experimental approach has a consistent and reproducible sensitivity to enable a robust QTcI risk evaluation and can be used confidently to support an integrated nonclinical-clinical pro-arrhythmia risk assessment. The inclusion of power analysis (i.e., QTc sensitivity) data in a regulatory submission provides key information to critical stakeholders about the quality of the in vivo QTc assessment and its value for human safety testing., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Doxorubicin-related heart failure has been recognized as a serious complication of cancer chemotherapy. This paper describes a cardiovascular safety pharmacology study with chronic dosing of doxorubicin in a non-human primate model designed to characterize the onset and magnitude of left ventricular dysfunction (LVD) using invasive and non-invasive methods. Methods: Cynomolgus monkeys ( N = 12) were given repeated intravenous injections of doxorubicin over 135 days (19 weeks) with dosing holidays when there was evidence of significantly decreased hematopoiesis; a separate group ( N = 12) received vehicle. Arterial and left ventricular pressure telemetry and cardiac imaging by echocardiography allowed regular hemodynamic assessments and determination of LVD. Blood samples were collected for hematology, clinical chemistry, and assessment of cardiac troponin (cTnI) and N-terminal pro b-type natriuretic peptide (NT-proBNP). Myocardial histopathology was a terminal endpoint. Results: There was variable sensitivity to the onset of treatment effects, for example 25% of doxorubicin-treated animals exhibited LVD (e.g., decreases in ejection fraction) following 50-63 days (cumulative dose: 8-9 mg/kg) on study. All animals deteriorated into heart failure with additional dosing 135 days (total cumulative dose: 11-17 mg/kg). Reductions in arterial pressure and cardiac contractility, as well as QTc interval prolongation, was evident following doxorubicin-treatment. Both cTnI and NT-proBNP were inconsistently higher at the end of the study in animals with LVD. Measurements collected from control animals were consistent and stable over the same time frame. Minimal to mild, multifocal, vacuolar degeneration of cardiomyocytes was observed in 7 of 12 animals receiving doxorubicin and 0 of 12 animals receiving vehicle. Conclusions: This repeat-dose study of doxorubicin treatment in the cynomolgus monkey demonstrated a clinically relevant pattern of progressive heart failure. Importantly, the study revealed how both telemetry and non-invasive echocardiography measurements could track the gradual onset of LVD., Competing Interests: All authors were employed by Amgen, Inc. NE is employed by Seattle Genetics. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Engwall, Everds, Turk and Vargas.)

Defining an appropriate and efficient assessment of drug-induced corrected QT interval (QTc) prolongation (a surrogate marker of torsades de pointes arrhythmia) remains a concern of drug developers and regulators worldwide. In use for over 15 years, the nonclinical International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) S7B and clinical ICH E14 guidances describe three core assays (S7B: in vitro hERG current & in vivo QTc studies; E14: thorough QT study) that are used to assess the potential of drugs to cause delayed ventricular repolarization. Incorporating these assays during nonclinical or human testing of novel compounds has led to a low prevalence of QTc-prolonging drugs in clinical trials and no new drugs having been removed from the marketplace due to unexpected QTc prolongation. Despite this success, nonclinical evaluations of delayed repolarization still minimally influence ICH E14-based strategies for assessing clinical QTc prolongation and defining proarrhythmic risk. In particular, the value of ICH S7B-based "double-negative" nonclinical findings (low risk for hERG block and in vivo QTc prolongation at relevant clinical exposures) is underappreciated. These nonclinical data have additional value in assessing the risk of clinical QTc prolongation when clinical evaluations are limited by heart rate changes, low drug exposures, or high-dose safety considerations. The time has come to meaningfully merge nonclinical and clinical data to enable a more comprehensive, but flexible, clinical risk assessment strategy for QTc monitoring discussed in updated ICH E14 Questions and Answers. Implementing a fully integrated nonclinical/clinical risk assessment for compounds with double-negative nonclinical findings in the context of a low prevalence of clinical QTc prolongation would relieve the burden of unnecessary clinical QTc studies and streamline drug development., (© 2020 Amgen, Inc.; Pfizer, Inc.; Takeda Inc.; Bayer; Novartis; Merck; Bristol-Myers Squibb; and Janssen. Clinical Pharmacology & Therapeutics published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Omecamtiv mecarbil (OM) is a selective cardiac myosin activator (myotrope), currently in Phase 3 clinical investigation as a novel treatment for heart failure with reduced ejection fraction. OM increases cardiac contractility by enhancing interaction between myosin and actin in a calcium-independent fashion. This study aims to characterize the mechanism of action by evaluating its simultaneous effect on myocyte contractility and calcium-transients (CTs) in healthy canine ventricular myocytes. Left ventricular myocytes were isolated from canines and loaded with Fura-2 AM. With an IonOptix system, contractility parameters including amplitude and duration of sarcomere shortening, contraction and relaxation velocity, and resting sarcomere length were measured. CT parameters including amplitude at systole and diastole, velocity at systole and diastole, and duration at 50% from peak were simultaneously measured. OM was tested at 0.03, 0.1, 0.3, 1, and 3 µmol\L concentrations to simulate therapeutic human plasma exposure levels. OM and isoproterenol (ISO) demonstrated differential effects on CTs and myocyte contractility. OM increased contractility mainly by prolonging duration of contraction while ISO increased contractility mainly by augmenting the amplitude of contraction. ISO increased the amplitude and velocity of CT, shortened duration of CT concurrent with increasing myocyte contraction, while OM did not change the amplitude, velocity, and duration of CT up to 1 µmol\L. Decreases in relaxation velocity and increases in duration were present only at 3 µmol\L. In this translational myocyte model study, therapeutically relevant concentrations of OM increased contractility but did not alter intracellular CTs, a mechanism of action distinct from traditional calcitropes., (© 2020 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

To develop therapeutics for cardiovascular disease, especially heart failure, translational models for assessing cardiac contractility are necessary for preclinical target validation and lead optimization. The availability of stem cell-derived cardiomyocytes (SC-CM) has generated a great opportunity in developing new in-vitro models for assessing cardiac contractility. However, the immature phenotype of SC-CM is a well-recognized limitation in inotropic evaluation, especially regarding the lack of or diminished positive inotropic response to β-adrenergic agonists. Recent development of 3D engineered cardiac tissues (ECTs) using human induced pluripotent stem cell derived-cardiomyocytes (hiPSC-CM) in the Biowire TM II platform has shown improved maturation. To evaluate their suitability to detect drug-induced changes in cardiac contractility, positive inotropes with diverse mechanisms, including β-adrenergic agonists, PDE3 inhibitors, Ca 2+ -sensitizers, myosin and troponin activators, and an apelin receptor agonist, were tested blindly. A total of 8 compounds were evaluated, including dobutamine, milrinone, pimobendan, levosimendan, omecamtiv mecarbil, AMG1, AMG2, and pyr-apelin-13. Contractility was evaluated by analyzing the amplitude, velocity and duration of contraction and relaxation. All tested agents, except pyr-apelin-13, increased contractility by increasing the amplitude of contraction and velocity. In addition, myosin and troponin activators increase contraction duration. These results indicate that ECTs generated in the Biowire TM II platform can identify inotropes with different mechanisms and provides a human-based in-vitro model for evaluating potential therapeutics., Competing Interests: Declaration of Competing Interest Amgen Inc. provided study funding. YQ and HMV are employees and shareholders of Amgen Inc. NF, IP, RS, and RS are employees and shareholders of TARA Biosystems Inc., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Heart failure (HF) remains a grievous illness with poor prognosis even with optimal care. The apelin receptor (APJ) counteracts the pressor effect of angiotensin II, attenuates ischemic injury, and has the potential to be a novel target to treat HF. Intravenous administration of apelin improves cardiac function acutely in patients with HF. However, its short half-life restricts its use to infusion therapy. To identify a longer acting APJ agonist, we conducted a medicinal chemistry campaign, leading to the discovery of potent small-molecule APJ agonists with comparable activity to apelin by mimicking the C-terminal portion of apelin-13. Acute infusion increased systolic function and reduced systemic vascular resistance in 2 rat models of impaired cardiac function. Similar results were obtained in an anesthetized but not a conscious canine HF model. Chronic oral dosing in a rat myocardial infarction model reduced myocardial collagen content and improved diastolic function to a similar extent as losartan, a RAS antagonist standard-of-care therapy, but lacked additivity with coadministration. Collectively, this work demonstrates the feasibility of developing clinical, viable, potent small-molecule agonists that mimic the endogenous APJ ligand with more favorable drug-like properties and highlights potential limitations for APJ agonism for this indication.

Torsades de Pointes (TdP) is a type of ventricular arrhythmia which could be observed as an unwanted drug-induced cardiac side effect, and it is associated with repolarization abnormalities in single cells. The pharmacological evaluations of TdP risk in previous years mainly focused on the hERG channel due to its vital role in the repolarization of cardiomyocytes. However, only considering drug effects on hERG led to false positive predictions since the drug action on other ion channels can also have crucial regulatory effects on repolarization. To address the limitation of only evaluating hERG, the Comprehensive in Vitro Proarrhythmia Assay initiative has proposed to systematically integrate drug effects on multiple ion channels into in silico drug trial to improve TdP risk assessment. It is not clear how many ion channels are sufficient for reliable TdP risk predictions, and whether differences in IC 50 and Hill coefficient values from independent sources can lead to divergent in silico prediction outcomes. The rationale of this work is to investigate the above two questions using a computationally efficient population of human ventricular cells optimized to favor repolarization abnormality. Our blinded results based on two independent data sources confirm that simulations with the optimized population of human ventricular cell models enable efficient in silico drug screening, and also provide direct observation and mechanistic analysis of repolarization abnormality. Our results show that 1) the minimum set of ion channels required for reliable TdP risk predictions are Nav1.5 (peak), Cav1.2, and hERG; 2) for drugs with multiple ion channel blockage effects, moderate IC 50 variations combined with variable Hill coefficients can affect the accuracy of in silico predictions., (Copyright © 2020 Zhou, Qu, Passini, Bueno-Orovio, Liu, Vargas and Rodriguez.)

Off-target activities of drug candidates observed during in vitro pharmacological profiling frequently do not translate to adverse events (AEs) in human. This could be because off-target activities do not have functional consequences, are not observed at exposures achieved during clinical testing, or may not translate into clinical outcomes. We report clinical consequences of an off-target activity observed during profiling of AMG 337, a selective inhibitor of the mesenchymal-epithelial transition factor being evaluated for treatment of solid tumors. In our screen of 151 potential off-targets, AMG 337 inhibited only adenosine transporter (AT). During clinical trials, headache emerged as the dose-limiting AE in the first-in-human trial. It was thought that headache was caused by extracellular accumulation of adenosine from inhibition of AT by AMG 337 and subsequent adenosine-mediated vasodilation through adenosine receptors (ARs). Further nonclinical studies were performed to evaluate this hypothesis. AMG 337 inhibited AT function in dog and human cells in vitro and dog and human arteries ex vivo. In a dog telemetry study, AMG 337 caused hypotension, which was reduced by pretreatment with theophylline, an AR antagonist. Overall, nonclinical and clinical data suggested that headache was due to cerebral vasorelaxation caused by AMG 337-mediated inhibition of AT. When subjects were advised to drink coffee, an AR antagonist, prior to AMG 337, the severity of headaches was reduced, allowing them to continue treatment. These findings demonstrate the importance of carefully evaluating clinical observations during early drug development and the value of translational nonclinical studies to investigate the mechanism of action driving clinical observations., (Copyright © 2019. Published by Elsevier Inc.)

Calcitonin gene-related peptide (CGRP) and its receptor have been implicated as a key mediator in the pathophysiology of migraine. Thus, erenumab, a monoclonal antibody antagonist of the CGRP receptor, administered as a once monthly dose of 70 or 140 mg has been approved for the preventive treatment of migraine in adults. Due to the species specificity of erenumab, the cynomolgus monkey was used in the pharmacology, pharmacokinetics, and toxicology studies to support the clinical program. There were no effects of erenumab on platelets in vitro (by binding, activation or phagocytosis assays). Specific staining of human tissues with erenumab did not indicated any off-target binding. There were no erenumab-related findings in a cardiovascular safety pharmacology study in cynomolgus monkeys or in vitro in human isolated coronary arteries. Repeat-dose toxicology studies conducted in cynomolgus monkeys at dose levels up to 225 mg/kg (1 month) or up to 150 mg/kg (up to 6 months) with twice weekly subcutaneous (SC) doses showed no evidence of erenumab-mediated adverse toxicity. There were no effects on pregnancy, embryo-fetal or postnatal growth and development in an enhanced pre-postnatal development study in the cynomolgus monkey. There was evidence of placental transfer of erenumab based on measurable serum concentrations in the infants up to 3 months post birth. The maternal and developmental no-observed-effect level (NOEL) was the highest dose tested (50 mg/kg SC Q2W). These nonclinical data in total indicate no safety signal of concern to date and provide adequate margins of exposure between the observed safe doses in animals and clinical dose levels., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Contractility measurements using primary isolated cardiac myocytes (CM) have commonly been used in understanding the physiology and pharmacology of cellular mechanics. In the majority of studies, CM from healthy animals were used, and fewer studies were performed with CM from diseased hearts. To better understand the translational value of contractility on the cellular level of a diseased animal model, myocytes were isolated from left ventricles of a tachypacing-induced heart failure (HF) canine model, and their contractility was measured by recording sarcomere shortening using an image-based IonOptix video system. A side-by-side comparison study was performed in myocytes isolated from 13 normal and 5 tachypacing-induced HF canines by evaluating both basal contractility and pharmacological responses to inotropic agents with different mechanisms, including dobutamine, isoproterenol, milrinone, levosimendan, pimobendan, diltiazem, and flecainide. Myocytes isolated from HF canines exhibited compromised contractility at the sarcomere level in comparison to normal myocytes, specifically, HF myocytes have smaller sarcomere contraction amplitude, longer resting sarcomere length, slower velocity of contraction and relaxation. In addition, they have altered pharmacological responses compared to that of normal canines, with much less potent effects observed in the application of classic inotropic agents, such as isoproterenol, dobutamine, and milrinone. These results indicate that myocytes isolated from tachy-paced HF canines have altered physiological and pharmacological properties, which could be utilized for understanding pathophysiology and developing pharmacological interventions for HF., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Safety Pharmacology studies are conducted to characterize the confidence by which biologically active new chemical entities (NCE) may be anticipated as safe. Non-clinical safety pharmacology studies aim to detect and characterize potentially undesirable pharmacodynamic activities using an array of in silico, in vitro and in vivo animal models. While a broad spectrum of methodological innovation and advancement of the science occurs within the Safety Pharmacology Society, the society also focuses on partnerships with health authorities and technology providers and facilitates interaction with organizations of common interest such as pharmacology, physiology, neuroscience, cardiology and toxicology. Education remains a primary emphasis for the society through content derived from regional and annual meetings, webinars and publication of its works it seeks to inform the general scientific and regulatory community. In considering the future of safety pharmacology the society has developed a strategy to successfully navigate forward and not be mired in stagnation of the discipline. Strategy can be defined in numerous ways but generally involves establishing and setting goals, determining what actions are needed to achieve those goals, and mobilizing resources within the society to accomplish the actions. The discipline remains in rapid evolution and its coverage is certain to expand to provide better guidance for more systems in the next few years. This overview from the Safety Pharmacology Society will outline the strategic plan from 2016 to 2018 and beyond and provide insight into the future of the discipline which builds upon a previous strategic plan established in 2009., (Copyright © 2018 Elsevier Inc. All rights reserved.)

To assess drug-induced pro-arrhythmic risk, especially Torsades de Pointe (TdP), new models have been proposed, such as in-silico modeling of ventricular action potential (AP) and stem cell-derived cardiomyocytes (SC-CMs). Previously we evaluated the electrophysiological profile of 15 reference drugs in hESC-CMs and hiPSC-CMs for their effects on intracellular AP and extracellular field potential, respectively. Our findings indicated that SC-CMs exhibited immature phenotype and had the propensity to generate false positives in predicting TdP risk. To expand our knowledge with mature human cardiac tissues for drug-induced pro-arrhythmic risk assessment, human ventricular trabeculae (hVT) from ethically consented organ donors were used to evaluate the effects of the same 15 drugs (8 torsadogenic, 5 non-torsadogenic, and 2 discovery molecules) on AP parameters at 1 and 2 Hz. Each drug was tested blindly with 4 concentrations in duplicate trabeculae from 2 hearts. To identify the pro-arrhythmic risk of each drug, a pro-arrhythmic score was calculated as the weighted sum of percent drug-induced changes compared to baseline in various AP parameters, including AP duration and recognized pro-arrhythmia predictors such as triangulation, beat-to-beat variability and incidence of early-afterdepolarizations, at each concentration. In addition, to understand the translation of this preclinical hVT AP-based model to clinical studies, a ratio that relates each testing concentration to the human therapeutic unbound Cmax (Cmax) was calculated. At a ratio of 10, for the 8 torsadogenic drugs, 7 were correctly identified by the pro-arrhythmic score; 1 was mislabeled. For the 5 non-torsadogenic drugs, 4 were correctly identified as safe; 1 was mislabeled. Calculation of sensitivity, specificity, positive predictive value, and negative predictive value indicated excellent performance. For example, at a ratio of 10, scores for sensitivity, specificity, positive predictive value and negative predictive values were 0.88, 0.8, 0.88 and 0.8, respectively. Thus, the hVT AP-based model combined with the integrated analysis of pro-arrhythmic score can differentiate between torsadogenic and non-torsadogenic drugs, and has a greater predictive performance when compared to human SC-CM models.

Introduction: The Safety Pharmacology Society (SPS) has conducted a survey of its membership to identify industry practices related to testing considered in the Comprehensive In vitro Proarrhythmia Assay (CiPA)., Methods: Survey topics included nonclinical approaches to address proarrhythmia issues, conduct of in silico studies, in vitro ion channel testing methods used, drugs used as positive controls during the conduct of cardiac ion channel studies, types of arrhythmias observed in non-clinical studies and use of the anticipated CiPA ion channel assay., Results: In silico studies were used to evaluate effects on ventricular action potentials by only 15% of responders. In vitro assays were used mostly to assess QT prolongation (95%), cardiac Ca 2+ and Na + channel blockade (82%) and QT shortening or QRS prolongation (53%). For de-risking of candidate drugs for proarrhythmia, those assays most relevant to CiPA including cell lines stably expressing ion channels used to determine potency of drug block were most frequently used (89%) and human stem cell-derived or induced pluripotent stem cell cardiomyocytes (46%). Those in vivo assays related to general proarrhythmia derisking include ECG recording using implanted telemetry technology (88%), jacketed external telemetry (62%) and anesthetized animal models (53%). While the CiPA initiative was supported by 92% of responders, there may be some disconnect between current practice and future expectations, as explained., Discussion: Proarrhythmia liability assessment in drug development presently includes study types consistent with CiPA. It is anticipated that CiPA will develop into a workable solution to the concern that proarrhythmia liability testing remains suboptimal., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

As part of an ongoing effort at Amgen to develop a disease-modifying therapy for Alzheimer's disease, we have previously used the aminooxazoline xanthene (AOX) scaffold to generate potent and orally efficacious BACE1 inhibitors. While AOX-BACE1 inhibitors demonstrated acceptable cardiovascular safety margins, a retinal pathological finding in rat toxicological studies demanded further investigation. It has been widely postulated that such retinal toxicity might be related to off-target inhibition of Cathepsin D (CatD), a closely related aspartyl protease. We report the development of AOX-BACE1 inhibitors with improved selectivity against CatD by following a structure- and property-based approach. Our efforts culminated in the discovery of a picolinamide-substituted 3-aza-AOX-BACE1 inhibitor absent of retinal effects in an early screening rat toxicology study.

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., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)

The Safety Pharmacology Society (SPS) conducted an industry survey in 2015 to identify industry practices as they relate to central, peripheral and autonomic nervous system ('CNS') drug safety testing. One hundred fifty-eight (158) participants from Asia (16%), Europe (20%) and North America (56%) responded to the survey. 52% of participants were from pharmaceutical companies (>1000 employees). Oncology (67%) and neurology/psychiatry (66%) were the most frequent target indications pursued by companies followed by inflammation (48%), cardiovascular (43%), metabolic (39%), infectious (37%), orphan (32%) and respiratory (29%) diseases. Seizures (67% of participants), gait abnormalities (67%), tremors (65%), emesis (56%), sedation (52%) and salivation (47%) were the most commonly encountered CNS issues in pre-clinical drug development while headache (65%), emesis/nausea (60%), fatigue (51%) and dizziness (49%) were the most frequent issues encountered in Phase I clinical trials. 54% of respondents reported that a standard battery of tests applied to screen drug candidates was the approach most commonly used to address non-clinical CNS safety testing. A minority (14% of all participants) reported using electroencephalography (EEG) screening prior to animal inclusion on toxicology studies. The most frequent group size was n=8 for functional observation battery (FOB), polysomnography and seizure liability studies. FOB evaluations were conducted in a dedicated room (78%) by blinded personnel (66%) with control for circadian cycle (55%) effects (e.g., dosing at a standardized time; balancing time of day across treatment groups). The rat was reported as the most common species used for seizure liability, nerve conduction and drug-abuse liability testing., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Rendos, NK, Heredia Vargas, HM, Alipio, TC, Regis, RC, Romero, MA, and Signorile, JF. Differences in muscle activity during cable resistance training are influenced by variations in handle types. J Strength Cond Res 30(7): 2001-2009, 2016-There has been a recent resurgence in the use of cable machines for resistance training allowing movements that more effectively simulate daily activities and sports-specific movements. By necessity, these devices require a machine/human interface through some type of handle. Considerable data from material handling, industrial engineering, and exercise training studies indicate that handle qualities, especially size and shape, can significantly influence force production and muscular activity, particularly of the forearm muscles, which affect the critical link in activities that require object manipulation. The purpose for this study was to examine the influence of three different handle conditions: standard handle (StandH), ball handle with the cable between the index and middle fingers (BallIM), and ball handle with the cable between the middle and ring fingers (BallMR), on activity levels (rmsEMG) of the triceps brachii lateral and long heads (TriHLat, TriHLong), brachioradialis (BR), flexor carpi radialis (FCR), extensor carpi ulnaris, and extensor digitorum (ED) during eight repetitions of standing triceps pushdown performed from 90° to 0° elbow flexion at 1.5 s per contractile stage. Handle order was randomized. No significant differences were seen for triceps or BR rmsEMG across handle conditions; however, relative patterns of activation did vary for the forearm muscles by handle condition, with more coordinated activation levels for the FCR and ED during the ball handle conditions. In addition, the rmsEMG for the ED was significantly higher during the BallIM than any other condition and during the BallMR than the StandH. These results indicate that the use of ball handles with the cable passing between different fingers can vary the utilization patterns of selected forearm muscles and may therefore be advantageous for coaches, personal trainers, therapists, or bodybuilders for targeted training or rehabilitation of these muscles.

Evaluation of stem cell-derived cardiomyocytes (SC-CM) using multi-electrode array (MEA) has attracted attention as a novel model to detect drug-induced arrhythmia. An experiment was conducted to determine if MEA recording from human induced pluripotent SC-CM (hiPSC-CM) could assess proarrhythmic risk. Ten hERG blockers, 4 Na(+) blockers, and 1 IKs blocker were evaluated blindly. Eight drugs are associated with Torsades de Pointes (TdP) and 4 are not. Multiple parameters, including field potential duration (FPD), Na(+) slope, Na(+) amplitude, beat rate (BR), and early after-depolarization (EAD) were recorded. Minimum effective concentrations (MEC) that elicited a significant change were calculated. Our results determined that FPD and EAD were unable to distinguish torsadogenic from benign compounds, Na(+) slope and amplitude could not differentiate Na(+) channel blockade from hERG blockade, BR had an inconsistent response to pharmacological treatment, and that hiPSC-CM were, in general, insensitive to IKs inhibition. A ratio was calculated that relates MEC for evoking FPD prolongation, or triggering EAD, to the human therapeutic unbound Cmax (MEC/Cmax). The key finding was that the ratio was sensitive, but specificity was low. Consistently, the ratio had high positive predictive value and low negative predictive value. In conclusion, MEA recordings of hiPSC-CM were sensitive for FPD and EAD detection, but unable to distinguish agents with low- and high-risk for TdPs. Although some published reports suggested great potential for MEA recordings in hSC-CM to assess preclinical cardiac toxicity, the current evaluation implies that this model would have a high false-positive rate in regard to proarrhythmic risk., (© The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology.All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

As with other professional disciplines there is a growing need from within industry as well as global regulatory authorities for implementation of a certification process in order to assure that appropriate expertise is developed and quality standards are identified for professionals involved in the practice of Safety Pharmacology (SP). In order to meet this need, the Safety Pharmacology Society (SPS) has developed the Diplomate in Safety Pharmacology (DSP) certification process. There are many benefits to certification including authentication of the discipline within the overall pharmaceutical community and with regulatory authorities. It also encourages participation in SPS activities by other professionals (toxicologists, clinicians, academics) who wish to broaden their professional expertise. It provides an opportunity for candidates to strengthen their fundamental scientific knowledge, and stimulates the sharing of data, methods and model development in the form of publications and presentations on relevant topics in SP. Accreditation in SP occurs after candidates successfully complete a written certification examination conducted at the annual SPS meeting. The DSP exam consists primarily of material pertinent to the conduct of SP vital function core battery studies (i.e., cardiovascular, respiratory and central nervous systems), supplemental SP studies (i.e., renal/urinary, gastrointestinal, immunology, and hematology), Regulatory Guidelines (ICH Guidelines) as well as relevant cross-functional knowledge (e.g., physiology, pharmacology, toxicology, biochemistry, pathology, pharmacokinetics, dosing formulation, analytical methods, and statistics). Maintenance of the DSP certification results from the accrual of credits which are gained from a range of educational and scientific contributions. Eligibility requirements include a combination of at least a bachelor degree in science and two years of relevant professional SP experience and one poster presentation on a SP topic as first author at a recognized major scientific meeting., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Evaluating whether a new medication prolongs QT intervals is a critical safety activity that is conducted in a sensitive animal model during non-clinical drug development. The importance of QT liability detection has been reinforced by non-clinical [International Conference on Harmonization (ICH) S7B] and clinical (ICH E14) regulatory guidance from the International Conference on Harmonization. A key challenge for the cardiovascular safety community is to understand how the finding from a non-clinical in vivo QT assay in animals predicts the outcomes of a clinical QT evaluation in humans. The Health and Environmental Sciences Institute Pro-Arrhythmia Working Group performed a literature search (1960-2011) to identify both human and non-rodent animal studies that assessed QT signal concordance between species and identified drugs that prolonged or did not prolong the QT interval. The main finding was the excellent agreement between QT results in humans and non-rodent animals. Ninety-one percent (21 of 23) of drugs that prolonged the QT interval in humans also did so in animals, and 88% (15 of 17) of drugs that did not prolong the QT interval in humans had no effect on animals. This suggests that QT interval data derived from relevant non-rodent models has a 90% chance of predicting QT findings in humans. Disagreement can occur, but in the limited cases of QT discordance we identified, there appeared to be plausible explanations for the underlying disconnect between the human and non-rodent animal QT outcomes., (© 2015 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of The British Pharmacological Society.)

The β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is one of the most hotly pursued targets for the treatment of Alzheimer's disease. We used a structure- and property-based drug design approach to identify 2-aminooxazoline 3-azaxanthenes as potent BACE1 inhibitors which significantly reduced CSF and brain Aβ levels in a rat pharmacodynamic model. Compared to the initial lead 2, compound 28 exhibited reduced potential for QTc prolongation in a non-human primate cardiovascular safety model., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Oxytocin, a nine amino acid peptide, is highly conserved in placental mammals, including humans. Oxytocin has a physiological role in parturition and parenteral administration of the synthetic peptide is used to induce labor and control postpartum hemorrhage. Endogenous levels of oxytocin before labor are ∼20 pg/mL, but pharmacological administration of the peptide can achieve levels of 110 pg/mL (0.1 nmol/L) following intravenous administration. Cardiac arrhythmia and premature ventricular contractions have been associated with oxytocin administration in addition to QTc interval prolongation. In the conscious rabbit model, intravenous oxytocin produced QT and QTc prolongation. The mechanism of oxytocin-induced QTc prolongation is uncertain but could be the result of indirect changes in autonomic nervous tone, or a direct effect on the duration of cardiomyocyte repolarization. The purpose of this study was to examine the ability of oxytocin to alter cardiac repolarization directly. Two conventional models were used: QTc interval evaluation in the isolated rabbit heart (IRH) and assessment of action potential duration (APD) in human ventricular myocytes (HVM). Oxytocin did not prolong QTc intervals in IRH or APD in HVM when tested at suprapharmacological concentrations, for example, up to 1 μmol/L. The results indicate that oxytocin has very low risk for eliciting QTc and APD prolongation directly, and infer that the QTc changes observed in vivo may be attributed to an indirect mechanism.

Biotechnology-derived pharmaceuticals or biopharmaceuticals (BPs) are molecules such as monoclonal antibodies, soluble/decoy receptors, hormones, enzymes, cytokines, and growth factors that are produced in various biological expression systems and are used to diagnose, treat, or prevent various diseases. Safety pharmacology (SP) assessment of BPs has evolved since the approval of the first BP (recombinant human insulin) in 1982. This evolution is ongoing and is informed by various international harmonization guidelines. Based on these guidelines, the potential undesirable effect of every drug candidate (small molecule or BP) on the cardiovascular, central nervous, and respiratory systems, referred to as the "core battery," should be assessed prior to first-in-human administration. However, SP assessment of BPs poses unique challenges such as choice of test species and integration of SP parameters into repeat-dose toxicity studies. This chapter reviews the evolution of SP assessment of BPs using the approval packages of marketed BPs and discusses the past, current, and new and upcoming approach and methods that can be used to generate high-quality data for the assessment of SP of BPs.

BACE1 inhibition to prevent Aβ peptide formation is considered to be a potential route to a disease-modifying treatment for Alzheimer's disease. Previous efforts in our laboratory using a combined structure- and property-based approach have resulted in the identification of aminooxazoline xanthenes as potent BACE1 inhibitors. Herein, we report further optimization leading to the discovery of inhibitor 15 as an orally available and highly efficacious BACE1 inhibitor that robustly reduces CSF and brain Aβ levels in both rats and nonhuman primates. In addition, compound 15 exhibited low activity on the hERG ion channel and was well tolerated in an integrated cardiovascular safety model.

It is widely accepted that more needs to be done to bring new, safe, and efficacious drugs to the market. Cardiovascular toxicity detected both in early drug discovery as well as in the clinic, is a major contributor to the high failure rate of new molecules. The growth of translational safety offers a promising approach to improve the probability of success for new molecules. Here we describe a cross-company initiative to determine the concordance between the conscious telemetered dog and phase I outcome for 3 cardiovascular parameters. The data indicate that, in the context of the methods applied in this analysis, the ability to detect compounds that affect the corrected QT interval (QTc) was good within the 10-30x exposure range but the predictive or detective value for heart rate and diastolic blood pressure was poor. These findings may highlight opportunities to refine both the animal and the clinical study designs, as well as refocusing the assessment of value of dog cardiovascular assessments beyond phase 1. This investigation has also highlighted key considerations for cross-company data sharing and presents a unique learning opportunity to improve future translational projects., (© The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Objective: To assess the mercury accumulating capacity in contaminated soils from the community of Mina Santa Cruz, in the south of the department of Bolívar, Colombia, of the pepper plant (Capsicum annuum), in order to establish the risk to the health of the consuming population., Materials and Methods: Samples were taken from tissues (roots, stems, and leaves) of pepper plants grown in two soils contaminated with mercury and a control soil during the first five months of growth to determine total mercury through cold vapor atomic absorption spectrometry. Total mercury was determined in the samples of pepper plant fruits consumed in Mina Santa Cruz., Results: The mean concentrations of total mercury in the roots were higher than in stems and leaves. Accumulation in tissues was influenced by mercury levels in soil and the growth time of the plants. Mercury concentrations in fruits of pepper plant were lower than tolerable weekly intake provided by WHO., Conclusion: Percent of translocation of mercury to aerial parts of the plant were low in both control and contaminated soils. Despite low levels of mercury in this food, it is necessary to minimize the consumption of food contaminated with this metal.

Background and Purpose: During repeat-dose toxicity studies, ECGs are collected from chemically or physically-restrained animals over a short timeframe. This is problematic due to cardiovascular changes caused by manual restraint stress and anesthesia, and limited ECG sampling. These factors confound data interpretation, but may be overcome by using a non-invasive jacket-based ECG collection (JET). The current study investigated whether a jacketed external telemetry system could detect changes in cardiac intervals and heart rate in non-human primates (NHPs), previously implanted with a PCT transmitter., Experimental Approach: Twelve male cynomolgus monkeys were treated weekly with vehicle or sotalol (8, 16, 32 mg kg⁻¹) p.o. ECGs were collected continuously for 24 hours, following treatment, over 4 weeks. A satellite group of six NHPs was used for sotalol toxicokinetics., Key Results: Sotalol attained Cmax values 1-3 hours after dosing, and exhibited dose-proportional exposure. In jacketed NHPs, sotalol dose-dependently increased QT/QTc intervals, prolonged PR interval, and reduced heart rate. Significant QTc prolongation of 27, 54 and 76 msec was detected by JET after 8, 16, and 32 mg kg⁻¹ sotalol, respectively, compared with time-matched vehicle-treated animals. Overall, JET-derived PR, QT, QTc intervals, QRS duration, and heart rate correlated well with those derived from PCT., Conclusions and Implications: The current findings clearly support the use of JET to quantify cardiac interval and rhythm changes, capable of detecting QTc prolongation caused by sotalol. JET may be a preferred method compared to restraint-based ECG because high-density ECG sampling can be collected in unstressed conscious monkeys, over several weeks., (© 2013 The British Pharmacological Society.)

Introduction: Cardiac safety is of paramount importance in contemporary drug development. Efficient and sensitive evaluation of cardiac safety in the research and development of new molecular agents begins with preclinical in-vitro models. A new model that is currently under evaluation is the human embryonic stem-cell derived cardiac myocytes (hESC-CM) (Peng, Lacerda, Kirsch, Brown, & Bruening-Wright, 2010)., Methods: hESC-CM were exposed in-vitro to 15 test compounds, and action potentials (AP) recorded with perforated patch-clamp technique to assess changes in AP duration (APD90) and upstroke velocity (Vmax). The test compounds included: 10 hERG channel, 4 Na⁺ channel, and 1 IKs channel inhibitors. For comparison purposes, the test compounds were evaluated in the isolated rabbit heart assay (IRH) to determine changes in conduction (QRS) and repolarization (QTc). Potency at hERG, NaV1.5 and IKs channel was also determined., Results: For 7 of 10 hERG channel inhibitors, the potency values across the three functional assays were similar (≤5-fold). Three compounds (dofetilide, sertindole, and terfenadine) showed >10-fold discrepancy between hERG potency and inhibitory concentrations in the hESC-CM and IRH assays. Of the four Na⁺ channel inhibitors, only mexiletine exhibited similar potency values across the three assays (~3-fold); the others exhibited marked variation (>10-fold) in inhibitory potency. No effect on repolarization was observed in hESC-CM treated with a potent IKs blocker, but QTc prolongation was evident in the IRH., Discussion: The functional data indicate that hESC-CM are sensitive for detecting repolarization delay induced by hERG channel blockade, and AP prolongation correlated with potency in the hERG channel and IRH assays. However, hESC-CM were less sensitive for detecting depolarizing delay by Na⁺ channel blockers, and unable to detect delayed repolarization caused by IKs blockade., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Introduction: The Safety Pharmacology (SP) Society (SPS) conducted an industry survey in 2012 in an attempt to define current industry practices as they relate to inclusion of safety pharmacology (SP) endpoints into Toxicology studies., Methods: A total of 361 participants from Asia (9.1%), Europe (19.4%) and North America (71.4%) responded to the survey. The preponderance of respondents were toxicologists (53.2%) followed by safety pharmacologists (27.2%) and scientists involved in the conduct of both disciplines (19.6%). Most participants (58.6%) were from pharmaceutical companies employing more than 500 employees., Results: A majority (68.2%) reported having experience in designing, performing or interpreting the SP component of a study when performed as part of a toxicology study. Some participants (42.0%) had submitted data to a regulatory agency where ICHS7 studies were performed as part of a toxicology study rather than as a standalone study. When comparing species that were used in studies in which SP was added to toxicology studies, canines were the most frequently reported animals used for new chemical entities (NCE) whereas non-human (NH) primates were the most frequent for the assessment of biological agents. The most frequent primary motivator for adding ICHS7 SP endpoints to regulatory toxicology studies was to generate additional data to allow for determination of an integrated risk assessment thereby testing Confidence in Safety (CIS) to better manage and/or mitigate risk. The current ability to add safety pharmacology endpoints into regulatory toxicology studies was used to address a specific concern (by 42.1% of respondents) to allow management of risk more effectively (36.8%) or to generate data that contributes to cessation of the progression of a compound (21.1%). For an NCE, SP measurements in toxicology studies were conducted in addition to standalone SP studies (by 40.6% of respondents) or in addition/instead of standalone safety pharmacology studies (by 39.8% of respondents). For biological agents, a majority (74.3%) indicated SP measurements in toxicology were conducted instead of standalone studies as outlined in the ICHS6 guideline while inclusion of SP endpoints in toxicology studies for biological agents in addition to standalone studies was reported by only 25.7% of the respondents., Discussion: The survey highlights that obtaining regulatory agreement for the proposed combined SP/Tox study designs may be useful before study conduct in some cases. Respondents suggest that such discussion could occur at the pre-IND meeting before the IND/CTA enabling program., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Introduction: The evaluation of cardiovascular side-effects is a critical element in the development of all new drugs and chemicals. Cardiac safety issues are a major cause of attrition and withdrawal due to adverse drug reactions (ADRs) in pharmaceutical drug development., Methods: The evolution of the HESI Technical Committee on Cardiac Safety from 2000-2013 is presented as an example of an effective international consortium of academic, government, and industry scientists working to improve cardiac safety., Results and Discussion: The HESI Technical Committee Working Groups facilitated the development of a variety of platforms for resource sharing and communication among experts that led to innovative strategies for improved drug safety. The positive impacts arising from these Working Groups are described in this article., (Copyright © 2013 Elsevier Inc. All rights reserved.)