Maytansinoid

As one of the most commonly used cytotoxic payloads for antibody-drug conjugates (ADCs), maytansine is a macrolide alkaloid anti-microtubule drug. Its mechanism of action is to bind to the vinblastine binding site of tubulin, inhibit microtubule polymerization, block the process of cell mitosis, and ultimately promote the apoptosis of tumor cells. Compared with traditional chemotherapeutic drugs, the cytotoxicity of maytansine is 100-1000 times stronger than that of paclitaxel, so it is rarely directly used in single-agent chemotherapy. It is mainly conjugated with monoclonal antibodies through cleavable linkers to construct targeted ADC drugs, and has now become the core payload component of ADC products in the fields of multiple solid tumors such as HER2-positive breast cancer, non-small cell lung cancer and gastric cancer.

The rapid expansion of the global ADC market has directly driven the rising demand for maytansine API. The global market size of maytansine and its derivatives was approximately USD 320 million in 2023, and the compound annual growth rate is expected to remain above 18% by 2028. In terms of competitive landscape, the high-end API market has long been dominated by European and American pharmaceutical companies. As the patents of multiple ADCs carrying maytansine payloads expire successively, domestic pharmaceutical companies are accelerating the breakthrough of synthesis process barriers. At present, nearly 10 Chinese enterprises have submitted registration applications for maytansine API, with a cost about 40% lower than that of imported products, and they have gradually become the main suppliers in the global low- and medium-end market.

Maytansine was first developed by ImmunoGen, a US-based company, as the core raw material for ADC payloads. There is no separate original research preparation on the market yet, and the core compound patents for its related derivatives first expired in major markets such as the United States and the European Union in 2021. For the domestic market, as of now, there are 12 CDE registration numbers for maytansine API, 6 of which are in A status and can be used for association with domestic preparation declarations. A number of ADC preparations carrying maytansine have been approved for marketing in China, including mainstream products such as trastuzumab emtansine and disitamab vedotin, all of which have been included in the *List of Chemical Medicines* as reference preparations. (Data as of June 2025, please refer to the official CDE website for the latest information)

CATO provides a full set of maytansine impurity reference standards, most of which are in stock. In-stock products ordered before 16:00 will be shipped on the same day. They meet the compliance requirements of multiple regulations including the Chinese Pharmacopoeia and FDA, and can fully meet the reference standard use needs in various stages such as API R&D, quality research, and declaration and registration.