Regulatory Toxicology and Pharmacology最新文献

Advances in biosciences, chemistry, technology, and computer sciences have resulted in the unparalleled development of candidate New Approach Methodologies over the last few years. Many of these are potentially invaluable in the safety assessment of chemicals, but very few have been adopted for regulatory decision making. There is an immediate opportunity to use NAMs in safety assessment where the vision is to be able to predict risk more rapidly, accurately, and efficiently to further assure consumer safety.

In order to achieve this, the UK Food Standards Agency (FSA) and the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) have developed a roadmap towards acceptance and integration of these new approach methodologies into safety and risk assessments for regulatory decision making. The roadmap provides a UK blueprint for the transition of NAMs from the research laboratory to their use in regulatory decision making. This will require close collaboration across disciplines (chemists, toxicologists, informaticians, risk assessors and others), and across chemical sectors, to develop, verify and utilise appropriate models. Linking up internationally, and harmonization will be fundamental.

Protein A (PA) is a bacterial cell wall component of Staphylococcus aureus whose function is to bind to Immunoglobulin G (IgG). Given its ability to bind IgG as well as its stability and resistance to harsh acidic and basic cleaning conditions, it is commonly used in the affinity chromotography purification of biotherapeutics. This use can result in levels of PA being present in a drug product and subsequent patient exposure. Interestingly, PA was previously evaluated in clinical trials as well as supporting nonclinical studies, resulting in a database that enables the derivation of a health-based exposure limit (HBEL). Given the widespread use of PA in the pharmaceutical industry, the IQ DruSafe Impurities Safety Working Group (WG) evaluated the available information with the purpose of establishing a harmonized parenteral HBEL for PA. Based on this thorough, collaborative evaluation of nonclinical and clinical data available for PA, a parenteral HBEL of 1.2 μg/kg/dose (60 μg/dose for a 50 kg individual) is expected to be health protective for patients when it is present as an impurity in a biotherapeutic.

In recent years, a number of therapeutic peptides have been authorized in the EU market, and several others are in the clinical development phase or under assessment for full dossier or generic applications. Quality and safety guidelines specific to peptides are limited, and some aspects have to be considered. In particular, concerns relate to the analytical investigation for impurities and the toxicological assessment of these substances. The guidelines and the compendial pharmacopoeias provide certain references but that may be questionable if interpreted according to whether therapeutic peptides are considered chemical or biological entities, large or small. The characterization of peptide-related impurities cannot follow the small molecule approach but should consider aspects closely linked to the complex mechanisms of action that these large molecules can exert in the human body. Although direct genotoxic mechanisms cannot be excluded, hazardous interactions on biological systems cannot be ruled out, as in the case of natural peptide toxins and their specific interactions with cellular or membrane targets. From a regulatory perspective, only after specific risk identification and characterization should an equally specific safety threshold in relation to potential toxicity be defined.