Efficacy and safety of sapropterin dihydrochloride in patients with phenylketonuria: A meta-analysis of randomized controlled trials

Aims The aim of the present meta-analysis was to evaluate the efficacy and safety of sapropterin dihydrochloride in phenylketonuria (PKU) patients. Methods The following databases were searched for randomized controlled trials (RCT) regarding PKU patients treated with sapropterin dihydrochloride: PubMed, Embase, Cochrane Library and clinicaltrials. Two authors independently selected studies, assessed the risk of bias and extracted data. The meta-analysis was performed in RevMan 5.3 provided by the Cochrane Collaboration. Results Four studies met the inclusion criteria. In PKU patients with low blood phenylalanine (Phe) concentration, no significant difference was indicated for the decrease of Phe level (weighted mean difference (WMD) = -7.75 mu mol L-1; 95% confidence intervals (CI): -82.63 to 67.13, P = 0.84, I-2 = 0%), however, the dietary Phe tolerance was significantly improved in the sapropterin group (WMD = 19.89 mg kg(-1) d(-1); 95% CI: 10.26 to 29.52, P < 0.0001, I-2 = 0%). In PKU patients with high blood Phe level, sapropterin showed a significant lowering in blood Phe concentration (WMD = -225.31 mu mol L-1; 95% CI: -312.28 to -138.34, P < 0.00001, I-2 = 0%). There was no significant difference for adverse events. Conclusions Sapropterin could bring benefit for PKU patients with high or low Phe level, due to Phe reduction in a short time or dietary Phe tolerance improvement respectively. Sapropterin has an acceptable safety profile.