FDA Approves Biocon Biologics' Denosumab Biosimilars: Bosaya and Aukelso

The FDA has approved Bosaya (denosumab-kyqq) and Aukelso (denosumab-kyqq), the sixth pair of denosumab biosimilars to receive the green light from the agency.1 The approvals, granted to Biocon Biologics, will provide more affordable treatment options for people with osteoporosis and cancer-related bone conditions.

Bosaya is a biosimilar to the reference product Prolia, and Aukelso is a biosimilar to Xgeva. The FDA also granted a provisional interchangeability designation for both biosimilars. Clinical data demonstrated that both products had comparable quality, safety, and efficacy to their reference products.

Shreehas Tambe, CEO and managing director of Biocon Biologics, stated that the approvals were a significant milestone. "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," he said.

Indications and Safety Information

Bosaya was approved for treating postmenopausal women with osteoporosis at high risk for fracture and to increase bone mass in men with osteoporosis at high risk for fracture. It was also indicated for people with glucocorticoid-induced osteoporosis and for increasing bone mass in certain individuals receiving hormone ablation therapy for nonmetastatic prostate or breast cancer. Like its reference product, Bosaya carries a boxed warning for severe hypocalcemia in patients with advanced chronic kidney disease (CKD).

Aukelso was approved to prevent skeletal-related events in patients with multiple myeloma and bone metastases from solid tumors. It was also indicated to treat adults and skeletally mature adolescents with a giant cell tumor of bone and to treat hypercalcemia of malignancy that is refractory to bisphosphonate therapy. Key warnings include the risk of hypersensitivity reactions, severe symptomatic hypocalcemia, and osteonecrosis of the jaw (ONJ).

Denosumab is a human monoclonal antibody that works by targeting RANKL, a protein essential for the formation and survival of osteoclasts, which are the cells responsible for bone resorption. By inhibiting RANKL, denosumab reduces bone breakdown and increases bone mass and strength. In 2024, US sales for denosumab products totaled nearly $5 billion.

A Rapidly Expanding Market

The approval of Bosaya and Aukelso followed a series of denosumab biosimilar approvals over the past year and a half, intensifying competition in the market for bone health treatments.

Previous denosumab biosimilar approvals included:

• March 2024: Wyost and Jubbonti (denosumab-bddz) from Sandoz were the first biosimilars approved, referencing Xgeva and Prolia, respectively.2 They were also granted interchangeability and launched in the US in June 2025.3
• February 2025: Ospomyv (referencing Prolia) and Xbryk (referencing Xgeva) from Samsung Bioepis (denosumab-dssb) gained approval with an interchangeability designation.4
• March 2025: Stoboclo (referencing Prolia) and Osenvelt (referencing Xgeva) from Celltrion (denosumab-bmwo) were approved and launched in the US in July 2025.4
• March 2025: Conexxence (referencing Prolia) and Bomyntra (referencing Xgeva) from Fresenius Kabi (denosumab-bnht) were approved for all indications of their reference products and became commercially available on July 1, 2025.5
• September 2025: Bildyos (referencing Prolia) and Bilprevda (referencing Xgeva) from Shanghai Henlius Biotech and Organon (denosumab-nxxp) received approval, marking the fifth pair cleared by the FDA.6

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 18, 2025. https://www.prnewswire.com/news-releases/biocon-biologics-receives-us-food-and-drug-administration-approval-for-bosaya-and-aukelso-denosumab-biosimilars-302559101.html

2. Jeremias S. FDA approves first denosumab biosimilars. The Center for Biosimilars®. March 5, 2024. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/fda-approves-first-denosumab-biosimilar

3. Jeremias S. Wyost and Jubbonti launch as first denosumab biosimilars in the US. The Center for Biosimilars. June 2, 2025. Accessed September 2, 2025.  https://www.centerforbiosimilars.com/view/wyost-and-jubbonti-launch-as-first-denosumab-biosimilars-in-the-us

4. Jeremias S. Two more pairs of denosumab biosimilars enter US market. The Center for Biosimilars. July 9, 2025. Accessed September 2, 2025.  https://www.centerforbiosimilars.com/view/two-more-pairs-of-denosumab-biosimilars-enter-us-market

5. Santoro C. FDA approves another pair of denosumab biosimilars, Conexxence and Bomyntra. The Center for Biosimilars. March 27, 2025. Accessed September 2, 2025. https://www.centerforbiosimilars.com/view/fda-approves-another-pair-of-denosumab-biosimilars-conexxence-and-bomyntra

6. Jeremias S. FDA greenlights fifth pair of denosumab biosimilars: Bildyos and Bilprevda. The Center for Biosimilars. September 2, 2025. Accessed September 18, 2025. https://www.centerforbiosimilars.com/view/fda-greenlights-fifth-pair-of-denosumab-biosimilars-bildyos-and-bilprevda