OBJECTIVES: During marketing authorisation evaluations of drugs, regulators need to decide whether the benefits of a drug outweigh its risks. Even though there are uncertainties associated with these benefits and risks, currently there is no regulatory structured approach on how to describe and classify these uncertainties. Additionally, although the value of patient preference studies in regulatory decisions has been acknowledged, it is not known in what cases results from such studies could help the management of these uncertainties. This study aims to: i) develop a fit-for-purpose approach for classifying uncertainties during the benefit-risk assessment and ii) identify what type of uncertainties could be informed by preference studies.

METHODS: First, a literature review was performed to identify existing frameworks for classifying uncertainties. Second, concepts used in these frameworks were tailored to the regulatory decision-making context by applying them to regulatory assessments of oncology drugs (n=64). Third, the same assessments were reviewed to identify uncertainties where preference studies could help inform the assessment.

RESULTS: The literature review identified a framework that classified uncertainties according to their type, source and managing strategy. Applying these concepts to regulatory assessments led to the following definitions: i) issue: what are regulators uncertain about, ii) source: what is causing the uncertainty and iii) managing strategy: how are regulators addressing the uncertainty. Case examples where using preference data could support regulatory assessments were identified and compiled.

CONCLUSIONS: Results from this study could: i) improve the transparency and communication towards external stakeholders about the assessment, by allowing regulators to be more explicit about uncertainties and how they dealt with them during the assessment and ii) provide preliminary directions as to when conducting and using preference studies would be most valuable in regulatory benefit-risk assessment.