Celltrion Inc. received FDA approval for two biosimilar versions of Amgen’s blockbuster bone health drug denosumab, expanding the Korean drugmaker’s presence in the lucrative US biologics market.
The approved products—STOBOCLO and OSENVELT—reference Amgen’s PROLIA and XGEVA respectively, medications widely used to treat osteoporosis and prevent skeletal-related events in cancer patients. The biosimilars won’t hit the US market until June 2025, following a settlement agreement with Amgen.
Celltrion’s Chief Commercial Officer Thomas Nusbickel highlighted the approvals as advancing the company’s strategy to deliver cost-effective alternatives in areas with substantial unmet needs, particularly osteoporosis-related fractures and cancer-related skeletal complications.
The FDA based its decision on Phase III clinical trials demonstrating equivalent efficacy and pharmacodynamics compared to reference denosumab, with similar pharmacokinetic and safety profiles.
For postmenopausal women with osteoporosis, denosumab represents a lifetime therapy option, according to Professor Jean-Yves Reginster, who serves as Director of a WHO Collaborating Centre for Musculoskeletal Health.
With this approval, Celltrion strengthens its biosimilar portfolio while potentially increasing patient access through anticipated cost savings. The company had previously secured European approval for STOBOCLO in February 2025.
The US biosimilars market continues to expand as patents on original biologics expire, opening opportunities for companies like Celltrion to challenge established pharmaceutical players with lower-cost alternatives.
