Fosaprepitant

Chemotherapy-induced nausea and vomiting is a common adverse reaction that affects patient compliance during tumor treatment, among which the control of delayed-phase vomiting has long been a clinical challenge. As a representative derivative of neurokinin-1 (NK-1) receptor antagonist antiemetics, fosaprepitant is a prodrug of aprepitant. After entering the body, it can be rapidly converted into its active form, and highly selectively blocks the binding of NK-1 receptors in the central nervous system to substance P, thereby effectively inhibiting acute and delayed chemotherapy-related vomiting. It is particularly suitable for adult patients receiving highly emetogenic chemotherapy regimens, and can be combined with 5-hydroxytryptamine receptor antagonists and dexamethasone to form a standard triple antiemetic regimen, which greatly improves the vomiting control rate and enhances patients' treatment tolerance.

At present, the global market size of fosaprepitant has exceeded USD 1.2 billion, with a compound annual growth rate of approximately 8.2% in the past three years. The growth is mainly driven by the increasing penetration of anti-tumor treatment in emerging markets. In terms of the domestic market, with the implementation of the volume-based procurement policy, the terminal price of fosaprepitant injection has dropped by more than 80% compared with the initial stage of the original drug's launch. In 2023, the domestic market size exceeded RMB 1.8 billion, and there are more than 15 generic drug manufacturers. The demand for domestic substitution of APIs continues to be released, and the long-standing supply pattern dominated by imported APIs is gradually being broken.

The original developer of fosaprepitant is Merck Sharp & Dohme, with the original brand name Emend. Its core compound patent expired in the United States in 2023, and the core patent in China expired in 2022. The main dosage form approved for the original drug is powder for injection, with specifications of 115mg and 150mg. It has been included in the *Reference Listed Drug Catalogue of Chemical Drugs* issued by the NMPA, and is also listed in the FDA Reference Listed Drug Catalogue. At present, more than 20 domestic enterprises have obtained A status for their fosaprepitant APIs through CDE registration, and there are more than 20 corresponding manufacturers of approved fosaprepitant dimeglumine for injection. (Data as of June 2025, please refer to the official CDE website for the latest information)

CATO can provide a full set of impurity reference standards for fosaprepitant, covering all categories of process impurities, degradation impurities and isomer impurities. Most products are available from stock. Stock orders placed before 16:00 can be shipped on the same day. All reference standards meet the requirements of pharmacopeias and regulatory regulations of multiple countries including the Chinese Pharmacopoeia and FDA, and can fully meet the relevant needs of API enterprises in process research, quality research and consistency evaluation.