Transporters are significant in dictating drug pharmacokinetics, thus inhibition of transporter function can alter drug concentrations resulting in drug-drug interactions (DDIs). Because they can impact drug toxicity, transporter DDIs are a regulatory concern for which prediction of clinical effect from in vitro data is critical to understanding risk. Ten transporters require routine study prior to regulatory NDA submission, which could result in a lot of in vitro data being generated either 1) too early in the discovery/development timeline and potentially being surplus to requirements if an NCE fails for reasons of poor PK (and efficacy) or toxicity, or 2) too late to influence finalization of the clinical development plan resulting in perhaps unnecessary co-medication exclusions, impacting patient recruitment and thus delaying clinical trials. Both will have a cost and resource penalty. To minimize development risks, the right transporters should be studied at the right time to either mitigate DDI risk by frontloading certain studies, or by managing DDI risk in the clinical setting, and this webinar will describe strategies that could be employed towards this goal.