On 1 December 2025, Celltrion announced that it has signed a formulary listing contract with one of three undisclosed “major” US pharmacy benefit managers (PBM) for its denosumab biosimilars, Stoboclo® and Osenvelt®, referencing Amgen’s Prolia® and Xgeva®, respectively.
Under the agreement, Stoboclo® and Osenvelt® will be listed on all public and private insurance formularies operated by the PBM, and will also secure preferred drug status, enabling priority prescribing. Celltrion states that patient reimbursement will be available from January 2026. According to Celltrion, it is also pursuing transitional formulary listing agreements with the two undisclosed other “major” PBMs.
Additionally, Celltrion also announced that it has signed a listing contact with the fifth-largest PBM in the US for Stoboclo® and Osenvelt®, also resulting in the products being listed as a preferred drug on all public and private insurance formularies operated by the PBM.
In May 2024, Celltrion was sued by Amgen in the District Court of New Jersey for alleged infringement of 29 patents regarding denosumab. That litigation settled in January 2025, supporting the US launch of Celltrion’s denosumab biosimilars in July 2025.
There are seven pairs of denosumab biosimilars approved in the US: Sandoz’s Jubbonti® and Wyost® (approved March 2024, launched June 2025), Samsung Bioepis’ Obodence™ and Xbryk™ (approved February 2025, not yet launched), Celltrion’s Stoboclo® and Osenvelt® (approved March 2025, launched July 2025), Fresenius Kabi’s Conexxence® and Bomyntra® (approved March 2025, launched July 2025), Shanghai Henlius/Organon’s Bildyos® and Bilprevda® (approved September 2025, not yet launched), Biocon’s Bosaya™ and Aukelso™ (approved September 2025, launched October 2025), and Richter/Hikma’s Enoby™and Xtrenbo™ (approved September 2025, not yet launched).