Abstract: One study was included involving 39 participants who received either enzyme replacement therapy with galsulfase (recombinant human arylsulphatase B) or placebo. This small study was considered to be of overall unclear quality, since the authors did not report how both the allocation generation and concealment were performed. The key finding at 24 weeks in the 12-minute walk test was a statistically significant mean difference of 92.00 meters between the two groups in favour of the galsulfase group (95% confidence interval 11.00 to 172.00). While week 24 results for the three-minute stair climb demonstrated some improvement in the treatment group as compared to the placebo group, this was not significant, mean difference 5.70 (95% confidence interval -0.10 to 11.50). A significant decrease in the urinary glycosaminoglycan levels was observed in favour of the galsulfase group at 24 weeks, mean difference -227.00 (95% confidence interval -264.00 to -190.00). In general, the dose of galsulfase was well tolerated and there were no significant differences in relation to adverse events. These events include drug-related adverse events, serious and severe adverse events, those during infusion, drug-related adverse events during infusion, and deaths. More infusion-related reactions were observed in the galsulfase group and were managed with interruption or slowing of infusion rate or administration of antihistamines or corticosteroids drugs. No deaths occurred during the study. The results of one small study (based on 24-week randomised phase of the study and prior to the open-label extension) demonstrated that galsulfase is more effective than placebo in people with MPS VI, with significant improvements in the 12-minute walk test and a reduction in urinary glycosaminoglycans. There were no significant changes in cardiac or pulmonary functions, liver or spleen volume, overnight apnea-hypopnea, height and weight, quality of life and adverse effects. Further studies are needed to obtain more information on the long-term effectiveness and safety of enzyme replacement therapy with galsulfase.

Plain-language summary: The review includes one study with 39 people with mucopolysaccharidosis type VI aged between five and 20 years old. The study compared galsulfase to placebo (a substance which contains no medication) and people were selected for one treatment or the other randomly. The study lasted for 24 weeks (with an open-label extension period of an additional 24 weeks). Given that there is only one small study included, the evidence for this treatment is limited. The included study showed that motor function improved in people who had received galsulfase, especially in their ability to walk. There was also an improvement in the results of urine tests, which showed lower levels of the chemicals associated with MPS VI (glycosaminoglycan levels). These results were seen in a short study and may reflect only short-term effects. There were no significant differences between treatment with galsulfase and placebo in relation to adverse effects. More research is required to study the long-term effects on heart and lung function, quality of life and survival. The methods of the study design were not clearly described and the impact of this on possible bias is unclear.