"Common sense is hard work" but benefits from persistent collaboration: Lessons learnt from the development of The Collaborative Network for European Clinical Trials for Children (c4c) to support the conduct of paediatric clinical trials of medicines.

Introduction: The Collaborative Network for European Clinical Trials for Children (c4c) is a public private partnership with a developed infrastructure across European sites to support the design and conduct of multi-national academic and industry paediatric clinical trials. This paper aims to review the learning points identified during co-development of c4c processes by academic and industry partners. Methods: Study metrics were recorded. Learning points were captured during network development, categorized and included in a thematic analysis from which lessons learnt were identified. Results: 12 trials were supported by sites coordinated at national level and integrated at European level. A total of 9 CDA cycles were completed, resulting in 436 site CDAs signed in a median of 8.11 days. Lessons learnt included the importance of: relationship building by early engagement with partners; reducing misunderstanding by clear communication; flexibility, adaptability and experiential learning which are required for service improvement. Practical actions that infrastructure developers and users can take include operational planning with a view to fostering collaborations across stakeholders, sharing information about different approaches to clinical operations, and raising awareness of the need for explicit work on collaboration, communication, and planning. Traditionally, these activities are repeated for each trial. The use of a persistent network allows the benefits of collaboration to be recycled. Discussion: Building a successful framework for collaboration allows dedication and determination to carry over from one study to another. The initial investment of time to share assumptions and "state the obvious" by each user will support future trials.