Sapropterin

Hyperphenylalaninemia is a rare inherited metabolic disease. Without timely intervention, it will cause irreversible nerve damage, and the tetrahydrobiopterin (BH4) deficiency type is an important subtype of it, for which traditional dietary control is often difficult to achieve ideal blood phenylalanine compliance. Sapropterin, as a synthetic BH4 analog, is a therapeutic drug for rare diseases. It can supplement the insufficiency of endogenous BH4, activate the activity of phenylalanine hydroxylase, and accelerate the metabolism and decomposition of phenylalanine. This drug is suitable for patients of all ages with hyperphenylalaninemia who respond to BH4 treatment, including patients with BH4 deficiency and BH4-responsive patients with phenylketonuria (PKU). It can help patients maintain stable blood phenylalanine levels on the premise of appropriately relaxing dietary restrictions, and significantly reduce the risk of long-term nerve damage caused by the disease.

The current global market size of sapropterin is stable at around USD 300 million. Due to the fixed patient group of rare disease drugs, the market growth rate remains in the range of 3%-5%. The competitive landscape is characterized by the dominance of the original research drug, with few generic pharmaceutical enterprises entering the field, and the domestic market has long relied on imported supplies. With the gradual implementation of domestic rare disease security policies, the accessibility of drugs for patients has been continuously improved, and the domestic market penetration rate has increased from less than 10% in 2018 to 22% in 2023, and there is still a large room for the release of unmet clinical needs.

The original research enterprise of sapropterin is BioMarin Pharmaceutical, and the original trade name is Kuvan. Its core compound patents have expired in 2024 in major markets such as the United States and the European Union. The main dosage forms approved for the original research drug are oral tablets, with specifications including 100 mg and powder. The original preparation has been included in the FDA Reference Listed Drug Catalog, and has also been included in the *List of Chemical Drugs* of China. At present, there is no domestic sapropterin API approved for marketing and registration in China. The original preparation has been approved for import in China, and no domestic generic preparation has been approved yet. (Data as of June 2025, please refer to the official website of CDE for the latest information)

CATO provides a full set of sapropterin impurity reference standards, covering the full-chain research needs of starting materials, intermediates, degradation products, etc. Most products are in stock, and orders for in-stock products placed before 16:00 will be shipped on the same day. Meanwhile, they meet the compliance requirements of multiple regulations such as the Chinese Pharmacopoeia and FDA, and can effectively support the whole process of API R&D, quality research and registration declaration.