Which clinical trial designs and statistical approaches have been used in assessments of orphan maintenance by the European Medicines Agency between 2012 and 2022? A cross-sectional study.

Objectives: In the European Union, a new orphan medicinal product must demonstrate 'significant benefit' over approved medicinal products targeting the same indication. To demonstrate a significant benefit, comparisons between the new product and the already approved medicinal products-either directly by a head-to-head comparison within a clinical trial or indirectly as a cross-trial comparison-are necessary. In this study, we investigate the types of trial designs and statistical approaches used for demonstrating a significant benefit of a new orphan medicinal product against approved comparators used between 2012 and 2022.