In this webinar we want to feature Physiologically based pharmacokinetics (PBPK) as important tool in drug development [1], which is usually performed when results  from known clinicals scenarios are used to predict unknown scenarios [2]. PBPK modelling represents a subdiscipline of System Pharmacology striving to understand the fate of the drug in body including impact of drug-drug interactions (DDI) and drug-gene interactions (DGI) [3]. Despite its generic relevance for drug applications, only a few verified, freely accessible, modifiable, and comprehensive DDI PBPK models are available. The Open Systems Pharmacology (OSP) community aims to overcome this bottlenecks and to grow PBPK knowledge with an open science approach [4]. OSP offers professional open access and open-source software tools (PK-Sim/MoBi) including qualified CYP3A4 DDI networks. Recently this network has been expanded with a CYP1A2 and CYP2C19 network, which can be applied to investigate drug-drug-gene interactions (DDGI). In his presentation Tobias Kanacher will show you how you can leverage the OSP software platform and the community for your drug development project, with a special focus on DDI.