Amgen Sues Celltrion Over Biosimilars of Blockbuster Bone Drugs

Amgen Inc. accused Celltrion Inc. of infringing 29 patents with proposed biosimilar versions of blockbuster bone-strengthening drugs Prolia and Xgeva, whose domestic sales were more than 15% of Amgen’s 2023 revenue.

The patents cover denosumab, the active ingredient in both biologics, along with methods of manufacturing it and products containing it, according to a complaint filed Tuesday in the US District Court for the District of New Jersey. Prolia treats osteoporosis patients at high risk of bone fractures; Xgeva is used to prevent skeletal-related events in cancer patients with bone metastases.

The filing comes about a month after Amgen settled ...