On January 18, 2021, the China National Intellectual Property Administration (CNIPA) issued Invalidation Decision Nos. 47617 and 47618, declaring that Chinese Invention Patent No. 201410058250.0 (title: “Method and Kit for Quantitative Determination of Small Dense LDL Cholesterol”, hereinafter the “small dense LDL cholesterol assay patent”), owned by Denka Co., Ltd., is entirely valid, and rejecting the invalidation requests filed by the two requesters against this patent.

Beijing Caihe Law Firm was entrusted by Denka Co., Ltd. to act as the patentee’s representative in the above two invalidation proceedings.

Cholesterol in small dense low‑density lipoprotein (small, dense LDL) is, by its nature, very difficult to detect directly as a target analyte; specialized methods such as ultracentrifugation or separation are normally required. Through years of research and effort, Denka Co., Ltd. developed, in 2007, a technique that enables the direct detection of cholesterol in small dense LDL without such pretreatment. The sdLDL‑EX “Seiken” brand reagents launched by Denka were the world’s first products to apply this technology for direct measurement of cholesterol in small dense LDL. The small dense LDL cholesterol assay patent is the core patent derived from this technology.