Leflunomide

For the long-term management of chronic autoimmune diseases such as rheumatoid arthritis, drugs with both immunomodulatory and anti-inflammatory effects are the core components of clinical regimens. Leflunomide is an isoxazole class immunosuppressant. It blocks the pyrimidine synthesis pathway required for lymphocyte proliferation by inhibiting the activity of dihydroorotate dehydrogenase, thereby reducing the production of autoantibodies and alleviating inflammatory responses. In addition to adult rheumatoid arthritis, it is also approved for the treatment of lupus nephritis. It is a first-line disease-modifying antirheumatic drug recommended by domestic and foreign guidelines, which can effectively reduce the risk of progression of joint damage and improve the quality of life of patients in the long-term control of chronic diseases.

In 2023, the global leflunomide market size was approximately USD 480 million, with the Chinese market accounting for about 32%, and the compound annual growth rate in the past five years has remained at 3.7%. The current market is dominated by generic drugs. The number of domestic approved manufacturers of oral preparations has exceeded 20. After the implementation of centralized drug procurement, the terminal price has dropped by more than 70%, and clinical accessibility has been greatly improved, driving the continuous release of demand in the primary market. On the upstream API side, domestic manufacturers have become the main global suppliers by virtue of cost advantages, and their export volume accounts for more than 60% of the total global trade volume.

The original research enterprise of leflunomide is Sanofi, and the original brand name is "Arava". The expiration date of its core compound patent in the United States was 2009, and the compound patent in China expired in 2008. The main dosage form of the original drug is tablet, with specifications including 10mg and 20mg. It has been included in the *Catalogue of Reference Preparations of Chemical Drugs* of China, and is also listed in the FDA Reference Preparations Catalogue. Up to now, 12 domestic enterprises have obtained CDE registration for leflunomide APIs, all with the status of A (already used in marketed preparations). The approved oral preparation varieties cover two dosage forms: tablets and capsules. (Data as of October 2024, please refer to the official CDE website for the latest information)

CATO can provide a full set of leflunomide impurity reference standards. Most products are in stock. For in-stock products, orders placed before 16:00 will be shipped on the same day. The products fully comply with the regulatory requirements of the Chinese Pharmacopoeia, FDA and other regulations, and can provide stable and reliable reference standard support for API R&D, quality research and consistency evaluation.