Azathioprine

Rejection after organ transplantation and long-term management of autoimmune diseases have always been core challenges in the field of clinical immunology. As a classic purine analog immunosuppressant, azathioprine can interfere with the synthesis pathway of purine nucleotides, inhibit the proliferation and activation of lymphocytes, and reduce the attack of immune cells on autologous tissues or transplanted organs. It is mainly clinically used for the prevention of rejection after transplantation of solid organs such as kidney, heart and liver, and is also applicable to the second-line treatment of refractory autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and inflammatory bowel disease, providing an economical and reliable medication option for patients requiring long-term immune regulation.

The global azathioprine market size maintains a steady growth trend. The market size in 2023 was approximately USD 420 million, and the compound annual growth rate from 2024 to 2030 is expected to be around 3.1%. The growth momentum mainly comes from the increase in the number of transplantation surgeries and the improvement of the diagnosis rate of autoimmune diseases. In terms of the competitive landscape, the original research product accounts for about 32% of the global high-end market share, while generic drugs occupy the primary grassroots and developing markets with cost advantages. China is the core main producing area of global azathioprine API, with production capacity accounting for more than 60% of the total global supply. After the implementation of domestic centralized procurement, the terminal price of preparations has dropped by more than 45%, further improving the accessibility of the drug.

The original research enterprise of azathioprine is GlaxoSmithKline, with the original brand name Imuran. Its core compound patent expired globally in 1981, and there is no core patent restriction at present. The main dosage forms approved for the original research product include tablets and injections. The common specification of tablets is 50mg, and the specification of injection is 100mg. The original research tablets have been included in the China Listed Drug Catalogue as reference preparations, and are also included in the FDA Reference Preparations List. Up to now, there have been 12 azathioprine API registration records on the China CDE API Registration Platform, among which 8 have been publicized in status A. Both domestic and imported preparations have multiple approved marketing authorizations, which can fully meet the domestic clinical medication demand. (Data as of June 2025, please refer to the official CDE website for the latest information)

In response to the quality control and R&D needs of azathioprine, CATO can provide a full set of impurity reference standards for this API. Most products are available from stock. Stock orders submitted before 16:00 can be shipped on the same day. All reference standards meet the requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA, and can provide stable compliance support for the impurity research and quality consistency evaluation work of API manufacturers and preparation R&D institutions.