Table 3.

Approaches to future transporter studies

Ex vivo research  Build multidisciplinary research teams for tissue collection and study design, e.g., surgeons, pathologists, clinical study staff, basic researchers  Use optimal age distribution, e.g., tissues samples from fetuses, neonates, and young infants, where most developmental changes can be expected, as well as sample number to ensure adequate power to detect age-related changes  Establish high-quality tissue collections with detailed tissue handling description and detailed description of patient characteristics  Use protein quantification techniques (e.g., LC–MS) and develop tools to study activity with minimal amounts of human tissue

PK studies  Phenotyping studies with drugs that are clinically used, and consider microdosing studies  Blood sampling at similar times as clinical blood draws (opportunistic sampling)  Perform population PK analyses  Design drug–drug interaction studies

PGx studies  In pediatric populations, test genetic variants in transporters known to affect PKs or PDs in adults  Take into account PGx variation in affected drug-metabolizing enzymes as added variants  Include relevant age range: e.g., younger children and neonates  Design adequately powered studies

LC–MS liquid chromatography–mass spectrometry, PD pharmacodynamic, PGx pharmacogenetic, PK pharmacokinetic