A multi-site comparison of in vivo safety pharmacology studies conducted to support ICH S7A & B regulatory submissions.

INTRODUCTION: Parts A and B of the ICH S7 guidelines on safety pharmacology describe the in vivo studies that must be conducted prior to first time in man administration of any new pharmaceutical. ICH S7A requires a consideration of the sensitivity and reproducibility of the test systems used. This could encompass maintaining a dataset of historical pre-dose values, power analyses, as well as a demonstration of acceptable model sensitivity and robust pharmacological validation. During the process of outsourcing safety pharmacology studies to Charles River Laboratories, AstraZeneca set out to ensure that models were performed identically in each facility and saw this as an opportunity to review the inter-laboratory variability of these essential models. METHODS: The five in vivo studies outsourced were the conscious dog telemetry model for cardiovascular assessment, the rat whole body plethysmography model for respiratory assessment, the rat modified Irwin screen for central nervous system assessment, the rat charcoal meal study for gastrointestinal assessment and the rat metabolic cage study for assessment of renal function. Each study was validated with known reference compounds and data were compared across facilities. Statistical power was also calculated for each model. RESULTS: The results obtained indicated that each of the studies could be performed with comparable statistical power and could achieve a similar outcome, independent of facility. DISCUSSION: The consistency of results obtained from these models across multiple facilities was high thus providing confidence that the models can be run in different facilities and maintain compliance with ICH S7A and B.

A framework to assess the translation of safety pharmacology data to humans.

This article outlines a strategy for collecting accurate data for the determination of the sensitivity, specificity and predictive value of safety pharmacology models. This entails performing a retrospective analysis on commonly used safety pharmacology endpoints and an objective assessment of new non-clinical models. Such assessments require a systematic quantitative analysis of safety pharmacology parameters as well as clinical Phase I adverse events. Once the sensitivity, specificity and predictive capacity of models have been determined, they can be aligned within specific phases of the drug discovery and development pipeline for maximal impact, or removed from the screening cascade altogether. Furthermore, data will contribute to evidence-based decision-making based on the knowledge of the model sensitivity and specificity. This strategy should therefore contribute to the reduction of candidate drug attrition and a more appropriate use of animals. More data are needed to increase the power of analysis and enable more accurate comparisons of models e.g. pharmacokinetic/phamacodynamic (PK/PD) relationships as well as non-clinical and clinical outcomes for determining concordance. This task requires the collaboration and agreement of pharmaceutical companies to share data anonymously on proprietary and candidate drugs.

Benchmarking safety pharmacology regulatory packages and best practice.

INTRODUCTION: The objectives of this survey were to obtain a global information update regarding current industry perspectives that describe Safety Pharmacology programs as they relate to the ICH S7A and S7B regulatory guidelines but also to obtain a broader perspective of other practises practices in the field currently used by companies. Preliminary findings were presented at the 7th Annual Meeting of the Safety Pharmacology Society (SPS) (Edinburgh, Scotland, Sept 19-21, 2007). METHODS: The survey was distributed by the SPS to 125 pharmaceutical companies. Survey topics included (a) an update on ICH S7A and S7B practices, (b) frontloading Safety Pharmacology studies prior to selection of candidate drugs, (c) abuse and dependence-liability studies and (d) an extended evaluation of industry practises practices as assessed by Contract Research Organizations (CROs). RESULTS: Respondents (>94%) include GLP core battery (CV, CNS and respiratory) studies in the drug package submitted to regulatory agencies, and approximately 40% also submit studies on gastrointestinal and renal function. Respondents to the ICH S7B aspects indicate approximately 98% include the hERG assay and QT interval (in vivo) data in submissions, 63% include APD in vitro data and another 23% APD in vivo and other cardiac channel data (26%). SP frontloading is performed by 78% of all responding companies. Respondents indicate that 39% of these non-GLP CV studies are conducted before lead optimization (LO) and 85% during LO and before candidate drug selection. The hERG, CNS selectivity binding screens and rodent behavioral studies are frontloaded by 100%, 90% and 74% of respondents. Responding CROs (26) were surveyed on the services offered including Irwin or Functional Observational Battery (FOB) tests (70%), respiratory studies (85%), in vivo telemeterized dogs (69%) and in vitro CV studies (50%). Only 38% of SP studies are combined with toxicology studies at the CROs. DISCUSSION: The survey results indicate that ICH S7A core battery studies are implemented by most of the responding companies with a clear trend of an enhanced submission of renal and GI studies. The impact of ICH S7B is clear since, all respondents assess cardiac repolarization using cellular hERG (I(Kr)) and whole animal (QT interval) assays as a component of their safety assessment. Responses indicate a diversity of approaches for conducting abuse liability studies, which primarily use the methods of self-administration and drug discrimination. While early SP frontloading of studies seems to vary, the methods used appear to be generic to some extent and include in vitro 'off-target' evaluations and in vivo tests to determine the potential for CNS and cardiovascular issues.