Samidorphan

Opioid-induced itching (OIIP) is a common adverse reaction in scenarios of postoperative analgesia and cancer pain management, with an incidence rate as high as 80%. For a long time, there has been a lack of targeted treatment regimens, and the advent of samidorphan has filled this clinical gap. As a highly selective peripheral κ-opioid receptor agonist, it only acts on opioid receptors in the peripheral nervous system, does not penetrate the blood-brain barrier to affect the central analgesic effect, and has no central nervous system-related adverse reactions. At present, it is mainly used to treat opioid-related itching, and clinical research on indications such as chronic kidney disease-related itching and cholestatic itching is also ongoing. The applicable population covers perioperative patients, cancer pain patients who use opioid analgesics for a long time and other groups.

At present, the global market of targeted therapeutic drugs for itching is still in a stage of rapid expansion. As the first approved targeted therapeutic drug for OIIP, samidorphan has significant market growth potential. Public data shows that its global market size has exceeded USD 230 million in 2023, with a compound annual growth rate remaining above 35%. At present, the number of samidorphan preparations approved for marketing worldwide is relatively small, and the original research product occupies the vast majority of the market share. No generic preparations from local enterprises have been approved in China, the market has not yet entered a stage of full competition, and there is broad space for the localization of APIs and preparations.

The original research enterprise of samidorphan is Cara Therapeutics, with the original research trade name Korsuva. Its core compound patent expires in 2033 in the United States and in 2032 in China. The main dosage form approved for the original research product is intravenous injection, with a specification of 0.5mg/5mL, which has been included in the FDA Reference Listed Drug Catalog. As of the retrieval time, no samidorphan preparation has been approved for marketing in China, and there is no relevant registration number in A status in the CDE API registration database, so domestic clinical demand still relies on import channels. (Data as of July 2025, please refer to the official CDE website for the latest information)

CATO can provide a full set of impurity reference standards for samidorphan API. Most of the products are available from stock. For in-stock products, orders placed before 16:00 can be shipped on the same day. All products comply with the compliance requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA, and can provide stable reference standard support for relevant enterprises in the R&D and quality control links of APIs and preparations.