This paper argues that Intergovernmental Organisations (IGOs) can play a significant role in the processes of system transformation required by Grand Challenges. The reason is their potential to influence socio-technical regimes connected to policy areas in which they have authority. Supported by mandates, moral standing and technical expertise, IGOs act in two ways: operating with high level of political support, these organisations guide priority setting and norm development through the definition of collective problems and solutions, including STI aspects, establishing a shared vision; involving public and private actors, IGOs implement and protect novel practices that reinforce the new norms, from legally binding agreements to the creation of new spaces for international collaboration. These processes are examined here in the field of global health, where outside pressure directed at the intellectual property rules in connection to access to medicines prompted the WHO to define the health challenge as a need to stimulate innovation and ensure wide access to technology at the same time. Two of the solutions implemented by IGOs to achieve both goals are analysed: the Medicines Patent Pool, designed by UNITAID to fulfil access and innovation needs in relation to HIV/AIDS drugs, and WIPO Re;Search, set up by WIPO to support collaboration and accelerate discovery and product development for Neglected Tropical Diseases, Malaria and Tuberculosis. (C) 2016 The Author(s). Published by Elsevier B.V.