Ritlecitinib

In response to the unmet clinical needs for autoimmune diseases such as moderate to severe alopecia areata and ulcerative colitis, targeted therapy with JAK kinase inhibitors has opened up a more precise intervention path. Ritlecitinib is a highly selective JAK3 inhibitor. By irreversibly binding to the ATP-binding pocket of JAK3, it blocks the signal transduction of various inflammatory factors such as IL-2, IL-4 and IL-15, while not significantly inhibiting JAK1/2/TYK2, which reduces the risk of adverse reactions caused by off-target effects while reducing inflammatory responses. At present, this drug has been approved for the treatment of adolescents aged 12 years and older and adults with moderate to severe alopecia areata, and clinical studies for related indications such as ulcerative colitis and active psoriatic arthritis are also in the late stage of advancement.

The global prevalence of alopecia areata is approximately 0.1%-0.2%, of which about 30% of patients will progress to moderate to severe alopecia areata, and there was a lack of safe and effective systemic treatment regimens in the past. Relevant data show that the global sales of ritlecitinib have exceeded US$320 million in 2023. With the approval of more indications and market penetration, it is expected that its global market size will exceed US$1.5 billion in 2028, with a compound annual growth rate of 34%. The current market is dominated by the original research product, and no generic drug has been launched worldwide. A number of local Chinese pharmaceutical companies have launched bioequivalence trials. In the future, with the expiration of patents, the entry of generic drugs will further improve the accessibility of the drug.

The original research enterprise of ritlecitinib is Pfizer Inc., with the trade name LITFULO, and its core compound patent will expire in China in 2035. The main dosage form of the original research drug approved is hard capsule, with a specification of 50mg, which has been included in the FDA Reference Listed Drug Catalog, and is also included in the *Catalog of Reference Preparations for Chemical Drugs* issued by the China NMPA. As of now, there is no approved marketing registration number for ritlecitinib active pharmaceutical ingredient in China, and the original research preparation was approved by the NMPA for import and marketing in 2023. (Data as of November 2024, please refer to the official CDE website for the latest information)

CATO can provide a full set of ritlecitinib impurity reference standards, which comply with the compliance requirements of multiple regulatory systems such as Chinese Pharmacopoeia and FDA. Most of the products are in stock regularly, and orders placed before 16:00 can be shipped on the same day, which can provide stable reference standard supply support for customers in the stages of API and preparation R&D and quality research.