Being able to exploit large and heterogeneous medical data is crucial for realizing the promise of precision medicine to its full potential. Yet, currently, due to the presence of multiple and fragmented systems at different clinical sites, it is often difficult to enable researchers to access the data they need. Privacy and security concerns also represent major obstacles that need to be overcome in order to provide access to sensitive medical data that are usually not exposed by clinical sites for the fear of data leaks. To address these challenges, we propose a system that employs Glowing Bear as a common front end to the widespread clinical research platforms i2b2, tranSMART and MedCo. Our proposed system uses IRCT, the official implementation of the PIC-SURE API, which acts as an interoperability layer that translates clinical research queries into native API languages. With our work, we take a step towards the technical convergence of i2b2 and tranSMART, giving clinical sites the means to share their data more easily. Even more, with the support of MedCo, a cohort explorer with strong privacy and security guarantees based on federated i2b2 instances, we enable clinical sites to share sensitive data that would be difficult to share otherwise.