Novel LC–MS Assays Impacting CYP and Transporter Drug–Drug Interaction Evaluations

Abstract

Drug-drug interaction (DDI) potentials of new chemical entities (NCEs) are a major concern when patients require treatment with multiple drug regimens at the same time. When drug X is co-administered with drug Y, either drug has the potential to partially or totally alter absorption, distribution, metabolism and excretion (ADME) properties of the other. The alterations in the ADME properties of the drug X could result from inhibition or induction of Cytochrome P450 (CYP) enzymes or transporters and, thus, alter the co-administered drug's efficacy and safety. To ensure safety and efficacy of drugs, regulatory agencies across the globe and the pharmaceutical industries have embraced evaluations of DDI potential of an NCE early in the drug development program and continued postmarketing. The guidance documents, from the US FDA, provide recommendations on drug interaction study design, data analysis, implications for dosing and labeling recommendations [1,2]. In addition, a collaborative group of scientists, from the academia, regulatory agencies, pharmaceutical industry and contract research organizations (CROs), regularly organize conferences and publish white papers based on new research, new clinical studies and findings from recent regulatory reviews. For example, breakthroughs and outcomes, from rapidly growing transporter sciences, are disseminated through outputs from the International Transporter Consortium [3][4][5].There is a growing interest in exploring novel LC-MS/MS, LC-high resolution accurate mass spectrometry (LC-HRMS) or LC-MS/HRMS assays early in drug development to ensure DDI-related liabilities to establish safety and efficacy of an NCE. This special issue brings together some of the novel LC-MS applications and outlook from leaders in the field.In vitro cytochrome P450 DDI projections before the start of clinical trials DDI potentials, related to CYP and UDP-glucuronosyltranferase (UGT) enzymes, have been extensively investigated because collectively both enzymes account for more than 90% of the biotransformation of the NCEs used for human treatments [6,7]. Very recently, Yu et al. [8] reviewed a total of 103 drugs, including 14 combination therapies and published the data under a title of 'Risk of clinically relevant pharmacokinetic-based drug-drug interactions with drugs approved by the US Food and Drug Administration between 2013 and 2016'. Investigations of the ADME properties and DDI profiles of the drugs approved between 2013 and 2016, using the University of Washington Drug Interaction Database and each drug's NDA information, showed CYP3A to be involved in >65% of DDIs. Several LC-MS/MS-based high-throughput CYP inhibition and induction assays have been reported over the last 20 years to ensure the safety and efficacy of drugs when required for co-administration [9,10]. The commentary entitled 'Application of in vitro CYP and transporter assays to predict clinical drug-drug interactions' by Volpe and Balimane [11] provides the needed background on enzymes including Phase I, Phase II and...