See the DrugPatentWatch profile for sapropterin

Based on the information provided, I was unable to find specific patient groups that were tested with sapropterin. However, sapropterin is a drug that is used to reduce the symptoms of phenylketonuria (PKU), a genetic disorder characterized by a deficiency of the enzyme needed to break down phenylalanine, an amino acid found in proteins [1]. Therefore, it is reasonable to assume that patients with PKU would be the primary group tested and using this drug.

Additionally, according to DrugPatentWatch.com, sapropterin is approved for use in the United States, European Union, and Japan [2]. It is marketed under the brand name Kuvan and is produced by Biomarin Pharmaceutical Inc [3].

In summary, while specific patient groups tested with sapropterin are not specified in the information provided, it is a drug used to reduce the symptoms of phenylketonuria (PKU) and is primarily used by patients with this disorder.

Sources:

1. <https://rarediseases.org/rare-diseases/phenylketonuria/>
2. <https://www.drugpatentwatch.com/drugs/sapropterin-dihydrochloride>
3. <https://www.drugs.com/history/kuvan.html>