Editing Phenylketonuria (section)

===Enzyme substitutes===
In 2018, the FDA approved an enzyme substitute called [[pegvaliase]] which metabolizes phenylalanine.<ref name="FDA2018Sub">{{Cite web |title=Press Announcements - FDA approves a new treatment for PKU, a rare and serious genetic disease |url=https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm608835.htm |access-date=9 December 2018 |website=www.fda.gov |language=en}}</ref> It is for adults who are poorly managed on other treatments.<ref name=FDA2018Sub/>

[[Tetrahydrobiopterin]] (BH4) (a cofactor for the [[oxidation]] of phenylalanine) when taken by mouth can reduce [[blood]] levels of this amino acid in some people.<ref>{{Cite journal |last1=Burton |first1=Barbara K. |last2=Kar |first2=Santwana |last3=Kirkpatrick |first3=Peter |year=2008 |title=Sapropterin |journal=Nature Reviews Drug Discovery |volume=7 |issue=3 |pages=199–200 |doi=10.1038/nrd2540 |s2cid=263991793}}</ref><ref name="pmid18230057">{{Cite journal |vauthors=Michals-Matalon K |date=February 2008 |title=Sapropterin dihydrochloride, 6-R-L-erythro-5,6,7,8-tetrahydrobiopterin, in the treatment of phenylketonuria |journal=Expert Opinion on Investigational Drugs |volume=17 |issue=2 |pages=245–51 |doi=10.1517/13543784.17.2.245 |pmid=18230057 |s2cid=207475494}}</ref>