Cardiovascular (CV) parameters such as blood pressure (BP), electrocardiogram (ECG), and heart rate (HR) are routinely assessed in non-rodent toxicology studies, yet measurement quality varies by methodology—namely telemetry (implanted or jacketed) versus restraint-based techniques. This analysis examined how measurement methods affect baseline CV values and sensitivity to drug-induced effects. Data from three sources were analyzed: 495 toxicology studies from seven pharmaceutical companies (2015–2023), FDA recently approved drugs (47 NCEs, 26 NBEs in 2022–2023), and two major CROs (2020−2023). Studies involved dogs, minipigs, or non-human primates with dosing durations up to 52 weeks. Additional literature, proprietary data, and questionnaire informed baseline comparisons and statistical and pharmacological sensitivity. In our toxicology datasets, ECG was commonly collected, whereas BP was not. The selection of ECG and BP recording methods was mostly sponsor-dependent. Telemetry was predominantly used in short-duration studies; restraint-based snapshot methods were common in longer studies. Restraint consistently increased baseline BP and HR values and variability. QTc correction methods under restraint were inconsistent across sponsors/CROs. Statistical analysis was common with telemetry but infrequent under restraint. Case examples show that telemetry detected clinically-relevant BP or QTc changes; however, restraint methods usually did not. These findings demonstrate that restraint methods increase baseline values and variability, reducing pharmacological and statistical sensitivity to detect CV effects. Current practices appear driven by sponsor convention as well as scientific rationale. As ICH S7A/S7B evolve, re-evaluation of CV monitoring methods is warranted to enhance scientific rigor, regulatory alignment, and 3Rs compliance in nonclinical safety assessment.

Core battery cardiovascular (CV) parameters [e.g., arterial blood pressure (BP), electrocardiogram (ECG), heart rate (HR)] are recorded in non-rodent safety pharmacology and toxicology studies. Data is used to support drug development in accordance with regulatory guidelines (e.g., ICH S7A. S7B S6, S9 and M3(R2)). However, the quality of measurements varies based on the methods used, ranging from restraint (unacclimated) to telemetry (implanted or jacketed)-based recordings. This analysis reviewed and compared current practice regarding methodological approaches applied to the acquisition of CV data in repeat-dose non-rodent toxicology studies. The data was sourced from 7 Sponsors, 2 major CROs and FDA regulatory drug approvals. Studies evaluated data acquired from dogs or non-human primates (NHP) with study durations up to 52 weeks. A literature-based search and proprietary published examples were used to establish baseline CV values and to ascertain the ability of the different methodologies used to detect drug-induced CV effects. The literature search provided evidence that baseline CV (BP and HR) values are consistently higher in restrained versus non-invasive telemetry methods. Moxifloxacin and proprietary drugs showed that hERG-mediated QTc prolongation was detected in the clinic and in NHP or dog studies using telemetry methods but not in restrained surface‑lead snapshot methods. Data showed that the ECG is collected in most repeat-dose toxicology studies, but BP is usually not collected. Overall, telemetry-based methods account for 61 % of ECG recordings; while much less frequent, restraint-based methods are used for 44 % of BP recordings, when collected. The choice and usage of collection methods is highly sponsor-dependent, with restraint-based methods for individual sponsors ranging from 0 to 100 %. Data showed that telemetry-based methods are predominately used in short-duration studies for drug safety assessments, but restraint-based snapshot methods are used in longer-duration studies. The data compiled thus far serves as a basis to consider CV collection methods used in toxicology studies and to develop recommendations on the measurement of ECG and BP in non-rodent species in support of regulatory safety assessment studies.

INTRODUCTION:Cardiovascular (CV) parameters1 such as blood pressure (BP), electrocardiogram (ECG), and heart rate (HR) are recorded in non-rodent non-clinical safety studies to support drug development. However, measurement quality varies depending on the methodology used, including restraint-based or telemetry (implanted or jacketed) techniques. Measurement quality, in this context, refers to the sensitivity and reliability of CV measurements in affecting baseline values of measured CV parameters and in detecting pharmacological effects. This retrospective multifaceted analysis evaluated the impact of recording methods on baseline CV parameters and their statistical and pharmacological sensitivities in detecting drug-induced CV effects. METHODS:Data were collected from three sources: (i) 495 studies from seven pharmaceutical sponsors (2015-2023), (ii) FDA-approved drugs (47 NCEs, 26 NBEs from 2022 to 2023), and (iii) two major CROs (2020-2023). Studies were conducted in dogs, non-human primates (NHP), or minipigs, with treatment durations of up to 52 weeks. Additionally, literature-based and proprietary data were analyzed to assess baseline CV values and methodology sensitivity. A survey was conducted to evaluate statistical analysis practices in these studies. RESULTS:All 3 datasets showed that the ECG is collected in most repeat dose toxicology studies, but not BP; the findings were largely independent on the modality (i.e., NCE versus NBE) or the indication (i.e., oncology vs. non-oncology). The choice and usage of ECG and BP methods is highly sponsor-dependent, with restraint-based methods for individual sponsors ranging from 0 to 100 %. FDA data showed that telemetry-based methods are predominantly used in short, single dose toxicology/safety pharmacology studies for NCEs. Subsequent studies of longer duration employ predominantly restraint-based snapshot methods. CRO data showed that approximately 30 % of toxicology studies do not include ECGs; however, when an ECG is recorded it is primarily collected in restrained animals using a snapshot approach. BP is infrequently recorded, regardless of methodology, in repeat dose toxicology studies. The de novo analysis and literature-based search showed that baseline BP/HR values were highly variable with consistently higher means under restraint compared to telemetry methods. The root mean square errors for BP/HR were larger under restrained conditions, in both species. Under restrained conditions, the use of fixed formulae for HR-corrected QT resulted in inconsistent QTc values across sponsor and CROs. The survey showed that statistical analysis of ECG/BP data was infrequently performed under restrained conditions in contrast to telemetry-based methods. Proprietary and published case studies showed that drug-induced BP elevation or QTc prolongation observed clinically and in NHP or dog using telemetry were not reliably detected under restraint-based conditions, highlighting limitations of RB methods in CV safety evaluation. The data illustrate that animal restraint reduces the pharmacological and statistical sensitivities to detect CV effects. CONCLUSIONS:ECG and BP recording methods vary based on sponsor preference, experience and/or institutional practices in addition to scientific rationale. Literature and case studies confirm the limitations of restraint-based methods. As ICH S7A/S7B evolve, revisiting CV assessment practices is necessary to align with scientific, technological, regulatory, and 3Rs considerations, ultimately improving best practices for regulatory safety assessment.

Assessing the magnitude of QTc prolongation is crucial in drug development due to its association with Torsades de Pointes. Inhibition of the hERG channel, pivotal in cardiac repolarization, is a key factor in evaluating this risk. In this study, the relationship between hERG inhibition and QTc prolongation magnitude was investigated, with the aim to derive simple guidance on the required hERG margin to avoid a large (>20 ms) QTc prolongation. METHODS:Data from literature and FDA sources were searched for compounds with hERG IC50 values alongside clinical QTc data with paired plasma concentrations, or compounds demonstrating a clinical concentration-QTc relationship. Relationships between hERG inhibition, hERG IC50 margin to unbound plasma Cmax, and QTc prolongation magnitude were calculated. RESULTS:Analysis of 148 clinical QTc observations from 98 compounds revealed that compounds associated with QTc prolongation >10 ms typically exhibited hERG margins of ≤33-fold, while those exceeding 20 ms were generally associated with margins of ≤24-fold. QTc increases above 10 ms were not observed at hERG margins >100-fold. Based on 53 clinical concentration-QTc datasets, modest hERG inhibition levels of ∼4-6 % correlated with a 10 ms QTc prolongation, while ∼10-13 % inhibition corresponded to a 20 ms prolongation. CONCLUSIONS:This study enhances understanding of the relationship between hERG inhibition and QTc prolongation magnitude, by conducting analysis across a wide range of 98 compounds. This information can be used to determine the optimal hERG margin, particularly for drug discovery projects with limited scope to completely design-out hERG activity.

Pharmaceutical companies routinely screen compounds for hemodynamics related safety risk. In vitro secondary pharmacology is initially used to prioritize compounds while in vivo studies are later used to quantify and translate risk to humans. This strategy has shown limitations but could be improved via the incorporation of molecular findings in the animal-based toxicological risk assessment. The aim of this study is to develop a mathematical model for rat and dog species that can integrate secondary pharmacology modulation and therefore facilitate the overall pre-clinical safety translation assessment. Following an extensive literature review, we built two separate models recapitulating known regulation processes in dogs and rats. We describe the resulting models and show that they can reproduce a variety of interventions in both species. We also show that the models can incorporate the mechanisms of action of a pre-defined list of 50 pharmacological mechanisms whose modulation predict results consistent with known pharmacology. In conclusion, a mechanistic model of hemodynamics regulations in rat and dog species has been developed to support mechanism-based safety translation in drug discovery and development.

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.

GABAA receptors, members of the pentameric ligand-gated ion channel superfamily, are widely expressed in the central nervous system and mediate a broad range of pharmaco-toxicological effects including bidirectional changes to seizure threshold. Thus, detection of GABAA receptor-mediated seizure liabilities is a big, partly unmet need in early preclinical drug development. This is in part due to the plethora of allosteric binding sites that are present on different subtypes of GABAA receptors and the critical lack of screening methods that detect interactions with any of these sites. To improve in silico screening methods, we assembled an inventory of allosteric binding sites based on structural data. Pharmacophore models representing several of the binding sites were constructed. These models from the NeuroDeRisk IL Profiler were used for in silico screening of a compiled collection of drugs with known GABAA receptor interactions to generate testable hypotheses. Amoxapine was one of the hits identified and subjected to an array of in vitro assays to examine molecular and cellular effects on neuronal excitability and in vivo locomotor pattern changes in zebrafish larvae. An additional level of analysis for our compound collection is provided by pharmacovigilance alerts using FAERS data. Inspired by the Adverse Outcome Pathway framework, we postulate several candidate pathways leading from specific binding sites to acute seizure induction. The whole workflow can be utilized for any compound collection and should inform about GABAA receptor-mediated seizure risks more comprehensively compared to standard displacement screens, as it rests chiefly on functional data.

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.

Our goal is to accurately predict all types of cardiovascular events in patients utilising nonclinical cardiovascular safety data. In the past two decades, cardiovascular safety science has primarily focused on events associated with the electrocardiogram. Broadening out to other cardiovascular parameters, we share real-life case studies that highlight our progress towards improved and better-informed project progression based upon use of disease models, mechanism-based translation and structure-function relationships. To fulfil this goal, further advances in patient-relevant humanised models will be required to enable cardiovascular safety science to keep pace with the ever-changing landscape of novel therapeutic paradigms.

Off‐target pharmacology may contribute to both adverse and beneficial effects of a new drug. In vitro pharmacological profiling is often applied early in drug discovery; there are fewer reports addressing the relevance of broad profiles to clinical adverse effects. Here, we have characterized the pharmacological profile of the active metabolite of fostamatinib, R406, linking an understanding of drug selectivity to the increase in blood pressure observed in clinical studies. R406 was profiled in a broad range of in vitro assays to generate a comprehensive pharmacological profile and key targets were further investigated using functional and cellular assay systems. A combination of traditional literature searches and text‐mining approaches established potential mechanistic links between the profile of R406 and clinical side effects. R406 was selective outside the kinase domain, with only antagonist activity at the adenosine A3 receptor in the range relevant to clinical effects. R406 was less selective in the kinase domain, having activity at many protein kinases at therapeutically relevant concentrations when tested in multiple in vitro systems. Systematic literature analyses identified KDR as the probable target underlying the blood pressure increase observed in patients. While the in vitro pharmacological profile of R406 suggests a lack of selectivity among kinases, a combination of classical searching and text‐mining approaches rationalized the complex profile establishing linkage between off‐target pharmacology and clinically observed effects. These results demonstrate the utility of in vitro pharmacological profiling for a compound in late‐stage clinical development.