Recommendations for a minimum data set for monitoring gene therapy in hemophilia: Communication from the ISTH SSC Working Group on Gene Therapy

Independent data collection is crucial in addressing the challenges associated with gene therapy for hemophilia, which is a promising treatment option but requires careful monitoring and management of short-term and potential long-term safety concerns. The International Society on Thrombosis and Haemostasis (ISTH) has identified a minimum efficacy and safety data set included in the World Federation of Hemophilia Gene Therapy Registry (WFH GTR) that should be collected on a national basis at specific time points for each patient who has been treated with the gene therapy products. This Gene Therapy Minimum Data Set (GT-MDS) was developed to facilitate data collection and to ensure capturing the most relevant data and most known, unknown safety and efficacy parameters recently cited by the EMA. The concept of assembling a minimum data set is not about creating a new dataset, but rather about identifying a subset of critical and essential topics that should always be included. The GT-MDS is structured into three sections and comprises an abridged list of six topics during routine gene therapy follow-up, keeping the number of data points low but allowing for rapid and independent data evaluation. The WFH GTR dataset, developed by the WFH, the ISTH and other organizations, including industry partners in 2020, is comprehensive. The GT-MDS reports the minimum relevant information which should not be lost and is mandatory to be collected for all patients who undergo the gene therapy. Therefore, the implementation of the GTR and MDS empower and enhance the data collection at worldwide level.