Elosulfase alfa for mucopolysaccharidosis type IVA: Real-world experience in 7 patients from the Spanish Morquio-A early access program

Abstract

There is a growing interest in evaluating the effectiveness of enzyme replacement therapy (ERT) with elosulfasealfa in patients with mucopolysaccharidosis type IVA (MPS-IVA) under real-world conditions. We present theexperience of seven pediatric MPS-IVA patients from the Spanish Morquio-A Early Access Program. Efficacy wasevaluated based on the distance walked in the 6-min walking test (6-MWT) and the 3-min-stair-climb-test (3-MSCT) at baseline and after 8 months of ERT treatment. Additionally, urinary glycosaminoglycans were mea-sured, and a molecular analysis of a GALNS mutation was performed. The health-related quality of life wasevaluated using the EuroQoL (EQ)-5D-5 L.The distance walked according to the 6-MWT ranged from 0 to 325 m at baseline and increased to 12–300 mafter 8 months with elosulfase alfa (the walked distance improved in all patients except one). An increase wasobserved for the two patients who had to use a wheelchair. Improvements were also observed for the 3-MSCT infour patients, whereas two patients showed no changes. Three patients showed an improvement in the EQ-VASscore, whereas the scores of three patients remained stable. Regarding urinary glycosaminoglycans measure-ments, an irregular response was observed. Our results showed overall improvement in endurance and func-tionality after 8 months of elosulfase alfa treatment in a heterogeneous subset of MPS IVA patients with severeclinical manifestations managed in a real-world setting.