Case study using RWD in the context of a pivotal trial for regulatory approval in a rare disease.

Rare disorders impact millions of children worldwide, and developing new medicines in this setting is associated with multiple challenges. In this paper, we share a successful story of how real-world data (RWD) were leveraged to accelerate evidence generation and patient access to a life-changing therapy in patients with severe manifestations of PIK3CA-related overgrowth spectrum who require systemic therapy. Despite all the existing regulatory guidelines considering real-world evidence (RWE), there is limited regulatory precedent of the use of this framework in support of a new indication. Thus, our case study illustrates design innovations based on the use of a compassionate use program, primarily in children, as a RWD source for approval of a new therapy in a rare disorder. We highlight the systematic considerations and mitigation of potential sources of bias in order to transform the data into actionable evidence. Our experience shows that RWE can be successfully used with appropriate study planning and mitigation in the context of a rare disorder with a high unmet medical need. Some lessons learned from this case study can benefit therapeutic development in rare disorders.