Based on the information available, it is unlikely that sapropterin alone can completely manage phenylketonuria (PKU) symptoms. PKU is a genetic disorder characterized by the body's inability to break down an amino acid called phenylalanine, leading to its buildup in the body, which can cause brain damage [1]. Sapropterin, a medication used to treat PKU, works by helping the body break down phenylalanine [2].

While sapropterin can help manage PKU symptoms, it is not a cure [3]. A PKU diet, which restricts phenylalanine intake, is still necessary for individuals with PKU, even if they are taking sapropterin [4]. In fact, the FDA-approved label for sapropterin states that it is indicated to reduce blood phenylalanine levels in individuals with PKU who have a specific genetic mutation and who are currently on a phenylalanine-restricted diet [5].

Therefore, while sapropterin can be a helpful tool in managing PKU symptoms, it cannot completely manage PKU symptoms on its own. A PKU diet and regular monitoring of blood phenylalanine levels are still necessary [6].

Sources:

1. National Institute of Diabetes and Digestive and Kidney Diseases. (2017). Phenylketonuria (PKU). <https://www.niddk.nih.gov/health-information/liver-disease/phenylketonuria-pku>
2. DrugPatentWatch.com. (n.d.). KUVAN (sapropterin dihydrochloride) Tablets. <https://www.drugpatentwatch.com/drugs/kuvan>
3. Genetics Home Reference. (2021). Phenylketonuria. <https://medlineplus.gov/genetics/condition/phenylketonuria/>
4. National PKU Alliance. (2021). PKU Diet. <https://www.npkua.org/about-pku/pku-diet/>
5. Food and Drug Administration. (2018). Highlights of Prescribing Information: KUVAN (sapropterin dihydrochloride) Tablets. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/021965s025lbl.pdf>
6. National PKU Alliance. (2021). PKU Management. <https://www.npkua.org/about-pku/pku-management/>