Key lessons from the first international treatment eligibility committee: the case of metachromatic leukodystrophy

Background: Treatment decisions in metachromatic leukodystrophy (MLD), a rare life-threatening neurological disease, are challenging. Hematopoietic stem cell transplantation or autologous stem-cell-based gene therapy can be life-changing but come with uncertainties, risks, and high costs. To address this, the international MLD treatment eligibility panel was established in collaboration with the European Reference Network on Rare Neurological Diseases. The panel reviews and discusses individual MLD cases and provides consensus-based recommendations on whether to treat and which treatment modality. The goal is to streamline international care and treatment counseling by providing uncomplicated access to expert opinion. Methods: The panel operates according to a published standard operating procedure and was evaluated between September 2021–2024. Case data were recorded in a Castor EDC-based system and, with consent, included in the MLD Initiative (MLDi) patient registry. Physicians' experiences were assessed via EUsurvey, and patients’ feedback was collected through an MLDi registry survey. Findings: The panel discussed 43 cases, recommending treatment in 20, abstaining in 19, and reaching no consensus in 4. Open questions regarding cognitive function and lack of outcome data caused challenges in treatment recommendations in late-onset MLD patients. All treatment recommendations were followed. Physicians reported positive experiences with the panel. Interpretation: The MLD treatment eligibility panel demonstrates how international expert advice can be streamlined across Europe for a rare disease like MLD, where disease-specific guidelines are still in development. By balancing complex clinical, social, and ethical parameters, the panel aids in encouraging appropriate use of innovative and costly therapies and guarantees accessibility to expert advice irrespective of country of origin.