Abemaciclib

HR+/HER2- breast cancer is one of the malignant tumor subtypes with the highest incidence rate among women worldwide, accounting for approximately 70% of all breast cancer cases. Drug resistance to traditional endocrine therapy is the core pain point in long-term clinical management. Abemaciclib belongs to the cyclin-dependent kinase 4/6 (CDK4/6) inhibitor class of anti-tumor drugs. It specifically blocks the phosphorylation of Rb protein mediated by CDK4/6, and arrests tumor cells from entering the S phase from the G1 phase, thereby inhibiting cell proliferation. Clinically, it can be used in combination with endocrine therapy for patients with HR+/HER2- locally advanced or metastatic breast cancer, and can also be used as a monotherapy for relapsed and refractory patients who have previously received endocrine therapy and chemotherapy. It is one of the core targeted drugs for the chronic disease management of advanced breast cancer at present.

Data show that the domestic market size of CDK4/6 inhibitors exceeded 6.5 billion yuan in 2024. Among them, abemaciclib, with the indication advantage of being the only one applicable for adjuvant treatment of early high-risk HR+/HER2- breast cancer, accounts for more than 52% of the market, and its compound annual growth rate has remained above 38% for 3 consecutive years. At present, abemaciclib generic drugs from 5 domestic enterprises have been approved for marketing. In the eighth batch of national centralized drug procurement in 2023, the average price of abemaciclib was reduced by 67%, which greatly improved the accessibility of drugs in public medical institutions. The expansion of the downstream preparation market has also driven the continuous rise in the demand for active pharmaceutical ingredients.

The original research enterprise of abemaciclib is Eli Lilly and Company, with the trade name "Verzenio®". Its compound patent in China will expire in November 2027, and its crystal form patent will expire in September 2030. The dosage form approved for the original research drug is tablet, with three specifications of 50mg, 100mg and 150mg, which has been included in the China Listed Medicines Catalogue as the reference listed drug. Up to now, there are 11 abemaciclib API registration entries on the CDE API Registration Platform, among which 8 have been marketed in China after passing the joint evaluation and approval with preparations, and the number of approved domestic preparations has exceeded 8. (Data as of June 2025, please refer to the official website of CDE for the latest information)

CATO provides a full set of impurity reference standards for abemaciclib API. The products meet the compliance requirements of multiple regulations including the Chinese Pharmacopoeia and FDA. Most categories are in regular stock. For in-stock orders, if placed before 16:00, they can be shipped on the same day, which can fully meet the reference standard use needs of pharmaceutical enterprises in the whole process of R&D, declaration and production.