BACKGROUND: Previous studies have shown that elosulfase alfa has a favorable efficacy/safety profile in Morquio A patients aged >/=5 years. This study evaluated safety and impact on urine keratan sulfate (uKS) levels and growth velocity in younger patients. METHODS: Fifteen Morquio A patients aged/kg/week for 52 weeks during the primary treatment phase of a phase II, open-label, multinational study. Primary endpoint was safety and tolerability, secondary endpoints were change in uKS and growth velocity over 52 weeks. RESULTS: All 15 patients completed the primary treatment phase. Six of 743 infusions (0.8%) administered led to adverse events (AEs) requiring infusion interruption and medical intervention. Eleven patients (73.3%) had >/=1 study drug-related AE, mostly infusion-associated reactions. Mean z-score growth rate per year numerically improved from 0.6 at baseline to 0.4 at week 52. Comparison to untreated subjects of similar age in the MorCAP study showed a smaller decrease in height z-scores for treated than for untreated patients. Mean percent change from baseline in uKS was 30.2% at 2 weeks and 43.5% at 52 weeks. CONCLUSION: Early intervention with elosulfase alfa is well-tolerated and produces a decrease in uKS and a trend towards improvement in growth.Pediatric Research (2015); doi:10.1038/pr.2015.169.
School of Medicine