Ambrisentan

Pulmonary arterial hypertension is a rare cardiovascular disease with rapid progression and high fatality rate, and clinical treatment options have been very limited for a long time. As a highly selective endothelin A receptor antagonist, ambrisentan can effectively reduce pulmonary vascular resistance by blocking endothelin-mediated vasoconstriction, and has minimal impact on endothelin B receptors, so the risk of liver injury is greatly reduced compared with non-selective antagonists. At present, this drug is mainly used to treat patients with pulmonary arterial hypertension of World Health Organization functional class II to III, which can significantly improve exercise tolerance and delay disease progression. It can also be combined with other targeted drugs for long-term management of severe patients, and is a first-line treatment recommended by domestic and foreign guidelines.

At present, the global market size of pulmonary arterial hypertension drugs has exceeded 8 billion US dollars, with a compound annual growth rate of around 7%, among which endothelin receptor antagonists account for nearly 40%. As a core variety of this category, the price of ambrisentan has dropped significantly after the launch of generic drugs, and its global annual sales are stable at more than 1.2 billion US dollars. In terms of the Chinese market, with the implementation of rare disease security policies, the sales of ambrisentan in public medical institutions exceeded 1.2 billion yuan in 2023, with an annual growth rate of more than 25%. There are more than 10 enterprises that have obtained approval for generic ambrisentan, and the drug has been included in the national centralized procurement. The winning bid price has dropped by more than 90% compared with the original research drug, and the accessibility for patients has been significantly improved.

The original research enterprise of ambrisentan is GlaxoSmithKline, and the original brand name is "Volibris". Its compound patent in China expired in 2021. The main dosage form approved for the original research drug is tablet, with specifications of 5mg and 10mg. It has been included in the *Catalogue of Reference Preparations of Chemical Drugs* of China, and is also included in the FDA Reference Preparations Catalogue. In terms of domestic API registration, more than 15 enterprises have obtained CDE registration numbers for ambrisentan APIs, most of which are in status A and can be used for associated review. In terms of preparations, in addition to the original research drug, 11 domestic enterprises have obtained approval for marketing of ambrisentan tablets. (Data as of June 2025, please refer to the official website of CDE for the latest information)

CATO provides a full set of ambrisentan impurity reference standards. The products meet the compliance requirements of multiple regulations such as the Chinese Pharmacopoeia and FDA. Most of the products are in regular stock. Spot orders submitted before 16:00 can be delivered on the same day, which can fully meet the reference standard needs of pharmaceutical enterprises in the whole process of R&D, quality research and production, and help enterprises shorten project cycles and control compliance risks.