3 Essai de confirmation et essai exploratoire


La problématique de la démarche hypothético-déductive a conduit à faire la distinction entre les essais de confirmation (confirmatory trial ) et les essais exploratoires (exploratory trial ). Les essais de confirmation sont les essais qui s’inscrivent dans la démarche hypothético-déductive contrairement aux essais exploratoires basés sur le raisonnement inductif.

Seuls les essais de confirmation peuvent apporter la preuve du bénéfice. Dans ICH, un essai de confirmation est défini comme un essai ayant explicitement fait l’hypothèse de ce qu’il veut démontrer. Par exemple, dans ICH E9 note n° 2 propose les définitions suivantes.

Confirmatory Trial : A confirmatory trial is an adequately controlled trial in which the hypotheses are stated in advance and evaluated. As a rule, confirmatory trials are necessary to provide firm evidence of efficacy or safety. In such trials the key hypothesis of interest follows directly from the trial’s primary objective, is always pre-defined, and is the hypothesis that is subsequently tested when the trial is complete.

Exploratory Trial : The rationale and design of confirmatory trials nearly always rests on earlier clinical work carried out in a series of exploratory studies. Like all clinical trials, these exploratory studies should have clear and precise objectives. However, in contrast to confirmatory trials, their objectives may not always lead to simple tests of pre-defined hypotheses. In addition, exploratory trials may sometimes require a more flexible approach to design so that changes can be made in response to accumulating results. Their analysis may entail data exploration; tests of hypothesis may be carried out, but the choice of hypothesis may be data dependent. Such trials cannot be the basis of the formal proof of efficacy, although they may contribute to the total body of relevant evidence

[2] https://www.ema.europa.eu/en/ich-e9-statistical-principles-clinical-trials