Nirmatrelvir

The global pandemic of COVID-19 has driven the R&D iteration of small-molecule antiviral drugs. As a representative variety of 3CL protease inhibitors, nirmatrelvir is one of the core components of compound antiviral preparations. It specifically inhibits the activity of the 3CL protease of SARS-CoV-2, blocks the cleavage process of viral polyproteins, and then prevents the replication and assembly of viruses. In clinical practice, it is often used in combination with ritonavir for the treatment of adult patients with mild to moderate COVID-19 who have high risk factors for progression to severe disease, especially suitable for elderly people and high-risk infected people with underlying diseases (such as chronic cardiopulmonary diseases, diabetes, immunodeficiency, etc.), which can significantly reduce the risk of hospitalization and death.

The global anti-COVID-19 small-molecule drug market still maintains stable demand after the peak of the epidemic, with a market size of approximately USD 4.2 billion in 2023, among which nirmatrelvir-related preparations account for nearly 40%. As many countries around the world have adjusted COVID-19 infection to "Category B infectious diseases managed under Category B protocols", the preventive and therapeutic needs of key populations have become the main driving factors of the market, and the compound annual growth rate is expected to remain at around 6% from 2024 to 2028. In terms of the competitive landscape, the original research products still occupy the mainstream market. In China, more than 10 enterprises have submitted marketing applications for generic nirmatrelvir preparations, and more than 20 enterprises have completed CDE registration for APIs. As the centralized procurement policy gradually covers this therapeutic field, the market space of domestic APIs with controllable costs will be further released.

The original research enterprise of nirmatrelvir is Pfizer, and the trade name of the original research compound preparation is "Paxlovid". The expiration date of its core compound patent in the United States is 2030, and the expiration date of the compound patent in China is 2031. The dosage form of the original research product approved in China is tablet, each containing 150 mg of nirmatrelvir and 100 mg of ritonavir. It has been included in the *Catalogue of Reference Preparations of Chemical Drugs* issued by the National Medical Products Administration, and is also a reference preparation recognized by the FDA. Up to now, there are more than 30 CDE registration numbers for nirmatrelvir APIs in China, among which nearly 10 are in Status A (can be used in marketed drugs), and a number of domestic nirmatrelvir/ritonavir preparations have been approved for marketing. (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 nirmatrelvir API, covering process impurities, degradation impurities and enantiomers that may be generated during the synthesis process. All products meet the compliance requirements of multiple regulatory systems such as Chinese Pharmacopoeia and FDA. Most products are in stock. Stock orders placed before 16:00 can be shipped on the same day, which can fully meet the reference standard needs in the stages of API R&D, quality research and declaration.