Many scholars have described the capacity of patient organizations to produce and acquire a form of lay expertise to confront (and in some cases, partner with) medical knowledge. While this learning process has been crucial for the empowerment of these patient organizations, another kind of activism seems to have emerged. This managerial activism implies the acquisition of bureaucratic and economic skills necessary to argue in front of public authorities and to protest against the economic valuation of the treatment for a disease. Recently, the association Vaincre la Mucoviscidose has decided to enroll experts to question the setting of prices for the treatment of cystic fibrosis. This paper analyses how this critique has been made possible and the ways in which it implies a new kind of participation by patient organizations in health policies.