FDA Approves 2 Denosumab Biosimilars in High Fracture Risk Populations, Including in Breast and Prostate Cancer

The FDA has approved denosumab-kyqq (Bosaya) 60 mg/mL injection for subcutaneous use in a single dose prefilled syringe, and denosumab-kyqq (Aukelso) 120 mg/1.7 mL (70 mg/mL) injection for subcutaneous use in a single-dose vial as biosimilars for reference denosumab (Prolia) and denosumab (Xgeva), respectively.1 The regulatory agency also granted provisional interchangeability designation for Bosaya and Aukelso.

Clinical data demonstrated comparable quality, safety, and efficacy between both biosimilars to the reference products. Like Prolia, Bosaya is approved with the same Risk Evaluation and Mitigation Strategy plan to provide awareness around the associated treatment-related risks of severe hypocalcemia in patients with advanced chronic kidney disease, including dialysis-dependent patients.

What Are the Newly Approved Indications for Bosaya and Aukelso?

Bosaya is approved in the same indications as Prolia.2 Specifically, it is indicated 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.1

Aukelso is approved in the same indications as Xgeva,3 specifically for the prevention of skeletal-related events in patients with multiple myeloma and in patients with bone metastases from solid tumors, to treat adults and skeletally mature adolescents with giant cell tumor of bone that is unresectable or where surgical resection is likely to result in severe morbidity, and to treat hypercalcemia of malignancy refractory to bisphosphonate therapy.1

“The FDA’s approval of Bosaya and Aukelso is a significant milestone in our mission to expand access to critical biologic therapies. With Bosaya, we are proud to offer a more affordable treatment option for patients with osteoporosis, and with Aukelso, we are further expanding our oncology care portfolio,” Shreehas Tambe, chief executive officer and managing director of Biocon Biologics, stated in a news release.

What Is the Need for Denosumab and What Prior Agents Were Approved in These Indications?

Denosumab is a human monoclonal antibody that targets and binds to Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL), which is responsible for the formation, function, and survival of the cells that enable bone resorption. By inhibiting RANKL, denosumab limits bone breakdown, resulting in greater bone mass and strength.

Prolia and Xgeva were first approved in 2010 for the treatment of postmenopausal women with osteoporosis at high risk for fracture or patients who have failed or are intolerant to other available osteoporosis therapy; and the prevention of skeletal-related events in patients with bone metastases from solid tumors, respectively.4,5

What Adverse Effects Should I Be Aware of When Prescribing Bosaya and Aukelso?

Common adverse effects (AEs) that occurred in at least 5% of patients receiving Bosaya across indications included back pain, pain in extremity, hypercholesterolemia, musculoskeletal pain, cystitis, arthralgia, nasopharyngitis, hypertension, bronchitis, and headache.1 Frequent AEs that were reported with Aukelso across indications included fatigue/asthenia, hypophosphatemia, nausea, diarrhea, anemia, back pain, thrombocytopenia, peripheral edema, hypocalcemia, upper respiratory tract infection, rash, headache, arthralgia, pain in extremity, dyspnea, decreased appetite, vomiting, and constipation.

Contraindications for both agents include hypocalcemia and known hypersensitivity, as well as pregnancy for Bosaya.1,4,5

“This achievement underscores our scientific and regulatory capabilities and reinforces our commitment to delivering high-quality biosimilars that support sustainable health care systems and improve patient outcomes,” Tambe concluded.1

References

1. Biocon Biologics receives U.S. Food and Drug Administration approval for Bosaya and Aukelso, denosumab biosimilars. News release. Biocon Biologics. September 17, 2025. Accessed September 17, 2025. https://www.biocon.com/biocon-biologics-receives-u-s-food-and-drug-administration-approval-for-bosaya-and-aukelso-denosumab-biosimilars/#:~:text=Denosumab%20is%20a%20human%20monoclonal,cells%20responsible%20for%20bone%20resorption
2. Prolia. Prescribing information. Amgen; 2024. Accessed September 17, 2025. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/125320s216lbl.pdf
3. Xgeva. Prescribing information. Amgen; 2020. Accessed September 17, 2025. https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/125320s203lbl.pdf
4. FDA approves Amgen’s Prolia (denosumab) for treatment of postmenopausal women with osteoporosis at high risk for fracture. News release. Amgen. June 1, 2010. Accessed September 17, 2025. https://www.amgen.com/newsroom/press-releases/2010/06/fda-approves-amgens-proliatm-denosumab-for-treatment-of-postmenopausal-women-with-osteoporosis-at-high-risk-for-fracture
5. FDA approves Amgen’s Xgeva (denosumab) for the prevention of skeletal-related events in patients with bone metastases from solid tumors. News release. Amgen. November 18, 2010. Accessed September 17, 2025. https://investors.amgen.com/news-releases/news-release-details/fda-approves-amgens-xgevatm-denosumab-prevention-skeletal