FDA Approves Denosumab-Dssb as Biosimilar for Prolia, Xgeva
Denosumab-dssb is approved as a 60 mg pre-filled syringe as a biosimilar for Prolia and 120 mg vial as a biosimilar for Xgeva.
The FDA approved denosumab-dssb (Ospomyv; previously SB16) and denosumab-dssb (Xbryk; previously SB16) as biosimilars referencing Prolia and Xgeva, respectively. Both drugs were granted provisional determination to interchangeability designation.1
The FDA approval was based on evidence including nonclinical and clinical data. | Image Credit: wladimir1804 | stock.adobe.com
"The FDA approval of Ospomyv and Xbryk marks a key step in improving patient access and alleviating treatment cost for patients with osteoporosis and cancer-related bone loss in the US,” Byoungin Jung, vice president and team leader of regulatory affairs at Samsung Bioepis, said in a news release.1 "By providing quality-proven biosimilars, we are helping to address a critical health care need and reduce the burden of skeletal fractures that impact patients’ quality of life."
The FDA approved Ospomyv for the treatment of postmenopausal women with osteoporosis at high risk for fracture, to increase bone mass in men with osteoporosis at high risk for fracture, 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. It was also approved as a 60 mg pre-filled syringe.1
For Xbryk, the FDA approved the drug for the prevention of skeletal-related events in patients with multiple myeloma and in patients with bone metastases from solid tumors, adults and skeletally mature adolescents with giant cell tumor of bone that is unresectable or where surgical resection could result in severe morbidity, and hypercalcemia of malignancy refractory to bisphosphate therapy. It was also approved as a 120 mg vial.1
The FDA approval was based on evidence including nonclinical and clinical data. In a phase 1 study, investigators found pharmacokinetic equivalence between the biosimilar, EU-sourced, and US-sourced denosumab for healthy male patients. In addition, investigators evaluated the efficacy and safety of the biosimilar compared to denosumab up to 18 months for postmenopausal women with osteoporosis. There were 457 patients initially included with 407 that received re-randomized treatment at month 12, which included continuing with denosumab, switching to the biosimilar, or continuing with the biosimilar through month 18. The primary efficacy outcome included percent change from baseline in bone mineral density at the lumbar spine, total hip, and femoral neck. Further, investigators evaluated the safety, pharmacodynamics, pharmacokinetics, and safety of the biosimilar.2
Investigators found that the mean percent changes from baseline in bone mineral density at month 18 were comparable across treatment groups. Specifically, investigators found that the mean change in lumbar spine was 6.8% for continuation with the biosimilar, 6.2% for switching to the biosimilar, and 6.8% for continuation of denosumab. Total hip increased at 4.4%, 3.5%, and 4%, respectively, and femoral neck at 3.4%, 3.1%, and 2.7%, respectively.2
Furthermore, investigators noted that the safety profiles were similar, with no new safety concerns identified after the switch. Of note, one patient in the switching group developed non-neutralizing anti-drug antibodies by month 18, according to the study authors.2
Investigators concluded that the “efficacy, safety, [pharmacodynamics], [pharmacokinetics], and immunogenicity were comparable between [postmenopausal] patients who switched to SB16 and those who continued [denosumab].”2
In 2024, the first biosimilar for denosumab was approved. Denosumab-bbdz (Wyost/Jubbonti) was the first biosimilar of the reference product and was given interchangeability designation, meaning the reference product can be swapped at the pharmacy level with this drug.3
READ MORE: Biosimilar Resource Center
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