Abstract Whilst patient engagement (PE) activities have become increasingly prevalent in development of medicines, collaborating actors have different perspectives on the goals of PE and its added value. In the production of PE standards and frameworks, the significance of these differences tends to be minimised. Boundary objects have been shown to mediate knowledge exchange between multiple social worlds, thereby playing an important role in participatory technology governance processes. In this article, we draw on boundary objects to learn from the process of co-designing a PE monitoring and evaluation (M&E) framework within the Innovative Medicines Initiative–Patients Active in Research and Dialogues for an Improved Generation of Medicines (IMI-PARADIGM) consortium (2018–20). As facilitators of PARADIGM’s co-design process, we report on the challenges encountered in developing a practicable M&E framework that serves a variety of needs and interests. We argue these challenges of co-design reflect a negotiation of different frames throughout, thereby providing insight into how such work may contribute to addressing the challenge of knowledge integration in institutional medicines development settings.