Palonosetron

Chemotherapy-induced nausea and vomiting (CINV) is one of the most common adverse reactions in cancer patients during the radiotherapy and chemotherapy stage. In severe cases, it will cause problems such as electrolyte imbalance and decreased treatment compliance, and the clinical demand for long-acting antiemetic drugs has always been urgent. Palonosetron is a second-generation 5-hydroxytryptamine 3 (5-HT₃) receptor antagonist. It reduces the vomiting reflex induced by chemotherapy stimulation by highly selectively blocking 5-HT₃ receptors in peripheral and central neurons. Compared with first-generation similar drugs, its affinity for receptors is increased by nearly 100 times, and its plasma half-life is as long as 40 hours. It can not only prevent acute CINV, but also has a particularly prominent inhibitory effect on delayed CINV. At present, it has been recommended by domestic and foreign antiemetic guidelines as a conventional antiemetic for moderate and highly emetogenic chemotherapy regimens, and the applicable population covers patients with solid tumors and hematological tumors receiving radiotherapy and chemotherapy.

The global palonosetron market size was approximately USD 780 million in 2024. Driven by the rising prevalence of tumors and the increasing penetration rate of chemotherapy, the compound annual growth rate is expected to remain at 5.2% by 2027. For the domestic market, the sales volume at public hospital terminals exceeded RMB 1.2 billion in 2023, of which injections accounted for more than 85%. The current competitive landscape is dominated by generic drugs, and more than 20 enterprises have obtained approval for the marketing of their preparations. This variety was included in the 7th batch of national centralized drug procurement in 2022, and the winning bid price decreased by an average of 72% compared with that before the centralized procurement, greatly improving clinical accessibility.

The original developer of palonosetron is Helsinn Healthcare of Switzerland, and the original products are sold under the brand names Akynzeo (a compound preparation containing netupitant/palonosetron) and the single-dose product Aloxi. The original compound patent expired in the United States in 2024, and the core compound patent in China expired in 2021. The main dosage forms of the original product include 0.25mg/5ml injection and 0.5mg hard capsule. The relevant dosage forms have been included in the FDA Reference Listed Drug Catalog, and the injection is also included in the *Catalog of Reference Listed Drugs for Chemical Drugs (Third Batch)* of China. Up to now, there are more than 30 registration numbers of palonosetron active pharmaceutical ingredients (APIs) in China, of which 22 are in A status, and the corresponding approved preparation varieties include palonosetron hydrochloride injection, palonosetron hydrochloride for injection, palonosetron hydrochloride capsules, etc. (Data as of June 2025, please refer to the official website of CDE for the latest information.)

CATO provides a full set of palonosetron impurity reference standards. 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 including the Chinese Pharmacopoeia and FDA, and can fully meet the reference substance use needs in API R&D, quality research and consistency evaluation links.