The FDA has approved 2 biosimilars, denosumab-nxxp (Bildyos) and (Bilprevda), referencing denosumab (Prolia) and denosumab (Xgeva), respectively, for use in all indications of the reference products.1
According to Henlius Biotech, these biosimilars received FDA approval following the review of a comprehensive package of structural and functional analytical data, clinical pharmacokinetic evaluations, and findings from a clinical study comparing the biosimilars with their reference products.Together, these data demonstrated that both biosimilars are highly similar to their respective reference products and exhibit no clinically meaningful differences in safety, potency, or purity.
Bildyos is indicated for postmenopausal women with osteoporosis at high risk for fracture; to increase bone mass in men with osteoporosis at high risk for fracture; for glucocorticoid-induced osteoporosis in men and women at high risk for fracture; to increase bone mass in men at high risk for fracture receiving androgen deprivation therapy for nonmetastatic prostate cancer; and to increase bone mass in women at high risk for fracture receiving adjuvant aromatase inhibitor therapy for breast cancer.
Bilprevda is indicated for the prevention of skeletal-related effects in patients with multiple myeloma and in patients with bone metastases from solid tumors; the treatment of adult and skeletally mature adolescent patients with giant cell tumor of bone that is unresectable or where surgical resection is likely to result in severe morbidity; and the management of hypercalcemia of malignancy refractory to bisphosphonate therapy.
“The FDA approvals of Bildyos and Bilprevda mark another set of Henlius’ self-developed and self-manufactured biosimilars approved in the United States [US], underscoring our commitment to scientific excellence and consistent product quality,” Jason Zhu, MD, executive director and chief executive officer of Henlius, noted in a news release. “We’re proud to continue expanding access to quality biologics through the collaboration with Organon, delivering biosimilar treatment options that are as safe and effective as the reference biologics to more patients across the US.”
Notably, on March 4, 2025 the FDA approved Stobloco and Osenvelt, which are also denosumab biosimilars for the same indications.2
Safety Information
The safety profile of denosumab products, including Bildyos, showed that in women with postmenopausal osteoporosis, the most common adverse effects (AEs) occurring in more than 5% of patients and at a higher frequency than placebo included back pain, pain in extremity, musculoskeletal pain, hypercholesterolemia, and cystitis.1 Among men with osteoporosis, commonly reported AEs (> 5% and more frequent than placebo) were back pain, arthralgia, and nasopharyngitis; cases of pancreatitis have also been observed.
In patients with glucocorticoid-induced osteoporosis, AEs reported in more than 3% of patients and more commonly than in an active-control group included back pain, hypertension, bronchitis, and headache. For patients with bone loss associated with androgen deprivation therapy for prostate cancer or adjuvant aromatase inhibitor therapy for breast cancer, the most frequently observed effects (≥ 10%) were arthralgia and back pain; pain in extremity and musculoskeletal pain were also reported in clinical trials. The most common adverse effect leading to treatment discontinuation in postmenopausal women with osteoporosis were back pain and constipation.
The safety information for Bilprevda showed that among patients with bone metastasis from solid tumors, the most common AEs (≥ 25%) were fatigue/asthenia, hypophosphatemia, and nausea. Among patients with multiple myeloma, the most frequently reported AEs (≥ 10%) were diarrhea, nausea, anemia, back pain, thrombocytopenia, peripheral edema, hypocalcemia, upper respiratory tract infection, rash, and headache. Among patients with giant cell tumor of bone, the most common AEs (≥ 10%) were arthralgia, back pain, pain in extremity, fatigue, headache, nausea, nasopharyngitis, musculoskeletal pain, toothache, vomiting, hypophosphatemia, constipation, diarrhea, and cough. Among patients with hypercalcemia of malignancy, the most common AEs (≥ 20%) were nausea, dyspnea, decreased appetite, headache, peripheral edema, vomiting, anemia, constipation, and diarrhea.
“These approvals are a testament to the strong collaboration between Henlius and Organon to expand patient access to quality and potentially more affordable biosimilars,” Ping Cao, chief business development officer and senior vice president of Henlius, added in the news release. “Together, we are working to broaden access to important treatment options and better meet the needs of both patients and providers in the US.”
References
- US Food and Drug Administration (FDA) approves Henlius and Organon’s Bildyos (denosumab-nxxp) and Bilprevda (denosumab-nxxp), biosimilars to Prolia (denosumab) and Xgeva (denosumab), respectively. September 2, 2025. https://www.henlius.com/en/NewsDetails-5427-26.html
- Celltrion receives U.S. FDA approval for Stoboclo (denosumab-bmwo) and Osenvelt (denosumab-bmwo) biosimilars referencing Prolia and Xgeva. Celltrion. March 4, 2025. Accessed March 4, 2025. https://www.celltrion.com/en-us/company/media-center/press-release/3768