Addressing unmet needs in rare diseases: A patient-centred vision through INFORM-RD.

Rare diseases collectively affect approximately 6% of the global population, yet 95% of affected individuals lack access to effective treatments. Beyond this persistent therapeutic gap, patients and caregivers face a broad spectrum of unmet needs, spanning psychosocial challenges, access to reliable diagnostic information, care coordination, and long-term follow-up, which remain poorly characterised in both clinical and policy contexts. Three interrelated challenges underpin this problem. First, validated instruments capable of systematically capturing unmet needs across diverse patient groups, including adults, minors, and caregivers, are largely absent. Second, even when patient data are collected, they are rarely integrated into clinical trial design, regulatory evaluation, or reimbursement deliberations in a structured and reproducible manner. Third, the responsible governance of rare disease data, particularly across institutional and national boundaries, faces unresolved ethical, legal, and organisational barriers. This perspective paper outlines the conceptual foundations of the INFORM-RD research project (a patient-informed clinical platform to inform patient-centred decision-making for rare diseases), embedded at KU Leuven, Leuven Institute for Rare Diseases and University Hospitals Leuven, Belgium. Drawing on the KCE NEED framework and leveraging a cohort of over 30,000 people with rare diseases, INFORM-RD aims to: 1) develop and validate a scalable methodology for unmet need data collection, 2) translate these data into actionable decision-support tools for clinicians, regulators, and payers, and 3) establish an ethical and legal governance architecture enabling responsible and scalable data sharing at national and international levels. By positioning patients, including underrepresented groups such as children and persons with cognitive limitations, as co-creators throughout the research process, INFORM-RD offers a transferable blueprint for need-driven rare disease care across Europe.