Brivudine

Herpes zoster is a highly prevalent viral infectious disease. People with low immunity often suffer from persistent and refractory neuralgia after infection, and there is always a clinical need for more efficient antiviral treatment options. Brivudine is a pyrimidine nucleoside antiviral drug that exerts its effect by selectively inhibiting the DNA replication of varicella-zoster virus. Compared with traditional acyclovir drugs, it has stronger antiviral activity and longer duration of action. It is mainly used for the treatment of acute herpes zoster in patients with normal immune function, and can also be used as adjuvant therapy for herpes zoster in immunosuppressed patients, which can significantly shorten the healing time of skin rashes and reduce the risk of postherpetic neuralgia.

At present, the global market size of brivudine is approximately US$180 million, with a compound annual growth rate of around 4.2%. The growth momentum mainly comes from the rising incidence of herpes zoster in the middle-aged and elderly population and the increasing clinical demand for highly active antiviral drugs. The domestic market is still in the introduction period. Due to the previous exclusive patent of the original research drug, the market supply has been dominated by imported products for a long time. With the expiration of the patent, the number of generic drug applications from domestic pharmaceutical enterprises has gradually increased, which is expected to further expand the overall market size.

The original research enterprise of brivudine is Berlin-Chemie AG, Germany, and the original trade name is "Zostex®". The expiration time of its core compound patent in Europe is 2017, and the compound patent in China has expired in 2019. The main dosage form approved for the original research drug is tablet, with a specification of 125mg. It has been included in the *Catalogue of Reference Preparations of Chemical Drugs* of China, and is also listed in the FDA Reference Preparations Catalogue. In terms of domestic API registration, a number of enterprises have submitted CDE registration numbers for brivudine API, some of which are in the marketed and in-use status, and a number of generic drug preparations have been approved for marketing in China. (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 brivudine API, which are developed in strict compliance with the requirements of multiple regulations such as the Chinese Pharmacopoeia and FDA. The impurity structure confirmation is complete, and the traceability system is sound. Most products can be supplied from stock. Stock orders paid before 16:00 can be shipped on the same day, which fully meets various reference standards use requirements in the stages of API R&D, quality research and consistency evaluation.