Is sapropterin treatment suitable for all subjects with phenylketonuria?
In a Phase I study, 20% of subjects with phenylketonuria (96/485) responded with a > or = 30% reduction in blood phenylalanine at day 8 of treatment with sapropterin. Subsequently, some of the responders from this study were enrolled in a Phase III study. The subjects with phenylketonuria were randomised to sapropterin 10 mg/kg/day (n = 41) or placebo (n = 47) for 6 weeks and continued their usual diet. The primary end point was the mean change from baseline in phenylalanine level after 6 weeks and there was a reduction of 235 micromol/l in the sapropterin group compared with 2.9 micromol/l in the placebo group. Thus, in the 20% of subjects with phenylketonuria that responded to a trial treatment with sapropterin, there were reduced mean blood phenylalanine levels over 6 weeks of treatment. In summary, sapropterin effectively reduces blood phenylalanine levels in a small proportion of subjects with phenylketonuria.
Doggrell
Sheila A
SA
RMIT University, Discipline of Pharmaceutical Sciences, School of Medical Sciences, Bundoora, Victoria 3083, Australia. sheila.doggrell@bigpond.com
D000293:Adolescent; D000328:Adult; D001708:Biopterins / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D017326:Clinical Trials, Phase III as Topic; D005260:Female; D006801:Humans; D008297:Male; D010649:Phenylalanine / Q000097:blood; D010661:Phenylketonurias / Q000097:blood / Q000188:drug therapy*; D016896:Treatment Outcome
D001708:Biopterins; D010649:Phenylalanine; C003402:sapropterin