Phase I trials often depend on healthy participants who are offered incentives for their participation, though this is not usually the case in, for example, cancer trials. Increasingly, phase I trials include participants with specific diseases for whom conventional therapy has failed. ###>Les essais de phase I font souvent appel à des participants en santé à qui on offre des incitations pour leur participation, quoique l’on ne procède habituellement pas ainsi dans les essais portant, par exemple, sur le cancer.