Strimvelis

Abstract: Strimvelis (autologous CD34+ cells transduced to express adenosine deaminase [ADA]) is the first ex vivo stem cell gene therapy approved by the European Medicines Agency (EMA), indicated as a single treatment for patients with ADA-severe combined immunodeficiency (ADA-SCID) who lack a suitable matched related bone marrow donor. Existing primary immunodeficiency registries are tailored to transplantation outcomes and do not capture the breadth of safety and efficacy endpoints required by the EMA for the long-term monitoring of gene therapies. Furthermore, for extended monitoring of Strimvelis, the young age of children treated, small patient numbers, and broad geographic distribution of patients all increase the risk of loss to follow-up before sufficient data have been collected. Establishing individual investigator sites would be impractical and uneconomical owing to the small number of patients from each location receiving Strimvelis. An observational registry has been established to monitor the safety and effectiveness of Strimvelis in up to 50 patients over a minimum of 15 years. To address the potential challenges highlighted above, data will be collected by a single investigator site at Ospedale San Raffaele (OSR), Milan, Italy, and entered into the registry via a central electronic platform. Patients/families and the patient’s local physician will also be able to submit healthcare information directly to the registry using a uniquely designed electronic platform. Data entry will be monitored by a Gene Therapy Registry Centre (funded by GlaxoSmithKline) who will ensure that necessary information is collected and flows between OSR, the patient/family and the patient’s local healthcare provider. The Strimvelis registry sets a precedent for the safety monitoring of future gene therapies. A unique, patient-focused design has been implemented to address the challenges of long-term follow-up of patients treated with gene therapy for a rare disease. Strategies to ensure data completeness and patient retention in the registry will help fulfil pharmacovigilance requirements. Collaboration with partners is being sought to expand from a treatment registry into a disease registry. Using practical and cost-efficient approaches, the Strimvelis registry is hoped to encourage further innovation in registry design within orphan drug development.

Abstract: GlaxoSmithKline's (GSK) and partner San Raffaele Telethon Institute for Gene Therapy's recent positive European approval for Strimvelis for treatment of severe combined immunodeficiency due to adenosine deaminase deficiency (ADA-SCID) represents the second EU-approved gene therapy and the first γ-retrovirus and first ex vivo gene therapy. In this article we discuss the significance and implications of this historic approval for the broader gene therapy field.

Abstract: Gene therapy is emerging as a viable option for clinical therapy of monogenic disorders and other genetically defined diseases, with approved gene therapies available in Europe and newly approved gene therapies in the United States. In the past 10 years, gene therapy has moved from a distant possibility, even in the minds of much of the scientific community, to being widely realized as a valuable therapeutic tool with wide-ranging potential. The U.S. Food and Drug Administration has recently approved Luxturna (Spark Therapeutics Inc, Philadelphia, PA, USA), a recombinant adeno-associated virus (rAAV) 2 gene therapy for one type of Leber congenital amaurosis 2 (1, 2). The European Medicines Agency (EMA) has approved 3 recombinant viral vector products: Glybera (UniQure, Amsterdam, The Netherlands), an rAAV vector for lipoprotein lipase deficiency; Strimvelis (Glaxo Smith-Kline, Brentford, United Kingdom), an ex vivo gammaretrovirus-based therapy for patients with adenosine deaminase–deficient severe combin...