Learnings from a registry-based cohort study for spinal muscular atrophy disease

Spinal muscular atrophy is a rare recessive progressive neurodegenerative disorder. To better understand the progression of spinal muscular atrophy the European Medicines Agency launched a study based on registry data. This manuscript describes some lessons learnt and considerations how to improve future registry-based studies that aim to inform regulatory decision-making. The study started with a feasibility assessment to select appropriate registries from the TREAT-NMD network. The feasibility assessment is key to understand upfront the quality, capability and capacity of registries to address a research question, as well as the potential limitations. Several tools are available on how to assess and ultimately improve data quality. Data from a registry becomes more valuable if it can be linked to other data sources to supplement data. For regulatory decision-making on orphan drugs, it is crucial to collect comprehensive data from non-treated patients. Missing information for important variables in non-treated patients complicates comparison with data from treated patients, as this may introduce bias into the results. Collaboration with registries has demonstrated opportunities for access to registry data and the steps needed to improve data quality. This requires more support in the form of funding, resources and training to understand the legal requirements.