In twenty years, NICE (National Institute for Clinical Excellence) has established itself as an international reference agency in the field of medico-economic evaluation. Created in 1999, the Institute has retained two specific features: the centrality of cost-results analyses in its work, and expertise in the field of medicine. NICE has acquired administrative skills in highly contested contexts, in which industrialists have tried to exert a persistent influence, as illustrated by the sociological analysis of the case of Interferon Beta in the treatment of multiple sclerosis. The 1995 introduction of this medication at a high price, in a context of the reorganization of the health care system, coincided with the creation of a national agency. But circumvention strategies implemented by industrialists demonstrate the forms of influence and even of interference with public decision-making leading to the invention of a “risk-sharing scheme”, the implementation of which is still ongoing. While circumventing the negative opinions of NICE, the agreement guarantees a sustained high price for controversial medicines in a debated context.