Clinical expert opinion on the role of elosulfase alfa in non-ambulatory individuals with Morquio A syndrome

Background: Morquio A syndrome is associated with progressive loss of ambulatory capacity. The impact of elosulfase alfa enzyme replacement therapy (ERT), the approved treatment for Morquio A, remains understudied in non-ambulatory patients. Methods: A modified Delphi study explored international expert opinions on drivers for using elosulfase alfa in non-ambulatory patients, potential treatment benefits in this population, and strategies for monitoring treatment impact. The study consisted of an initial exploratory virtual advisory board, anonymous voting on statements, and a survey to collect additional information. Results: Ten physicians with expertise in managing patients with Morquio A participated in the study. The experts reached ≥70% agreement on 14 statements; nine statements achieved 100% agreement. They agreed that mobility should not drive decisions to initiate, continue or discontinue treatment. ERT should be considered or continued as long as the benefits outweigh the burden of treatment. The decision to discontinue ERT should be based on clinician and patient/family consensus considering clinical status, health-related quality of life, and treatment burden. Clinical experience suggests that patients who cannot complete the 6MWT can still benefit from ERT. In these patients, treatment success may be measured using assessments of pulmonary function, hand dexterity, general functionality and pain, patient-reported symptoms, and quality of life assessments. Conclusions: This explorative study offers valuable insights into drivers of ERT use in non-ambulatory patients with Morquio A, its potential benefits, and strategies for monitoring treatment outcomes in clinical practice. These findings may guide patient management, optimize treatment, and inform future research for this population.