Tamoxifen

Estrogen receptor-positive breast cancer is the malignant tumor type with the highest incidence rate among women worldwide, and endocrine therapy is the core scheme for the whole-course management of such patients. Tamoxifen, as a classic representative of selective estrogen receptor modulators (SERM), competitively binds to estrogen receptors on breast tissue to block estrogen-mediated tumor cell proliferation signals. It is not only the baseline drug for postoperative adjuvant endocrine therapy of early HR-positive breast cancer, but also can be used for palliative treatment of advanced metastatic breast cancer. Meanwhile, it has been approved for the prevention of disease risk in high-risk groups of breast cancer. Its applicable population covers female patients of all age groups from young people to postmenopausal women, and it has been in clinical application for more than 40 years, making it one of the basic drugs recommended by global breast cancer treatment guidelines.

At present, the global tamoxifen market size is stable at around 1.2 billion US dollars. Driven by the rising incidence of breast cancer year by year, the compound annual growth rate in the past five years has remained at 3.2%. Affected by the centralized procurement policy in the domestic market, the price of preparations has dropped significantly, and clinical accessibility has been remarkably improved. In 2023, the sales volume of domestic sample hospitals was approximately 210 million yuan, and the actual terminal market size exceeded 800 million yuan. In terms of competition pattern, the market share of the original research product is less than 10%, and domestic generic drugs occupy a dominant position. Domestic API manufacturers are concentrated in Jiangsu, Zhejiang and other regions. There are more than 20 preparation enterprises that have passed the consistency evaluation, and the supply and demand pattern of APIs is relatively stable.

The original research enterprise of tamoxifen is AstraZeneca, and the original trade name is "Nolvadex". Its core compound patent expired globally in 1985. The main dosage form of the original research product on the market is tablet, with specifications of 10mg and 20mg. Among them, the 20mg specification has been included in the *Catalogue of Reference Preparations of Chemical Drugs* of China, and is also a reference preparation listed by the FDA. Up to now, there are more than 30 tamoxifen API registration entries on the API registration platform of China Center for Drug Evaluation (CDE), among which more than 20 are in the status of "A (approved for use in marketed preparations)". All tamoxifen preparations approved for marketing in China are tablets, and products from 22 enterprises have passed the consistency evaluation. (Data as of October 2024, please refer to the official website of CDE for the latest information)

CATO provides a full set of impurity reference standards for tamoxifen API. Most products are in stock. For in-stock products, orders placed before 16:00 will be shipped on the same day. The products meet the compliance requirements of multiple regulations such as Chinese Pharmacopoeia and FDA, and can fully meet the reference substance needs of pharmaceutical enterprises in the whole process of R&D, quality research and production, helping relevant preparation enterprises efficiently complete the consistency evaluation and marketing declaration work.