FDA Approves Bosaya and Aukelso Biosimilars for Solid Tumor Care

The U.S. Food and Drug Administration (FDA) has approved Bosaya (denosumab-kyqq) and Aukelso (denosumab-kyqq), biosimilars of Prolia and Xgeva, respectively, for men at high risk of fracture undergoing 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, according to a news release from Biocon Biologics Ltd. (BBL).

Bosaya has been approved as an injection for subcutaneous use in a single dose prefilled syringe, and Aukelso as an injection for subcutaneous use in a single-dose vial, respectively.

Biosimilars offer a lower-cost alternative to biologic medicines, used in the treatment of various cancers. Although not identical to the original biologic, these biosimilars must meet rigorous FDA standards to demonstrate that they are equally effective and safe as the reference brand-name products, according to the American Cancer Society website.

Shreehas Tambe, CEO & managing director of Biocon Biologics, highlighted the approval as a milestone in expanding patient access to critical biologic therapies. “With Bosaya, we provide a more affordable option for osteoporosis, and with Aukelso, we broaden our oncology care portfolio,” Tambe said. “This underscores our commitment to delivering high-quality biosimilars that improve patient outcomes and support sustainable healthcare systems.”

The release further notes that both treatments received provisional interchangeability designation, providing patients and healthcare providers greater flexibility in selecting these therapies.

Bosaya: Supporting Bone Health During Cancer Treatment

Bosaya is approved for multiple indications, including the prevention of bone loss in men undergoing androgen deprivation therapy for nonmetastatic prostate cancer and in women receiving adjuvant aromatase inhibitor therapy for breast cancer. These treatments are commonly used in cancer care but can weaken bones, increasing fracture risk. By targeting Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL), the agent reduces bone resorption, helping maintain bone strength and reduce fractures.

Clinical studies show Bosaya matches the quality, safety, and effectiveness of Prolia, the news release continues. However, patients with advanced chronic kidney disease, particularly those on dialysis, face a higher risk of severe hypocalcemia. Doctors will monitor calcium levels closely and ensure adequate supplementation with calcium and vitamin D. Common side effects include back pain, joint pain, and fatigue, with serious but rare risks such as osteonecrosis of the jaw and atypical femoral fractures.

For patients with prostate or breast cancer, maintaining bone health during hormone-based therapies is critical. Bosaya offers a biosimilar option that can make treatment more accessible while addressing this key aspect of cancer care.

Aukelso: Addressing Bone Complications in Advanced Cancer

Aukelso is approved to prevent skeletal-related events in patients with bone metastases from solid tumors, including breast and prostate cancers, and to treat multiple myeloma, giant cell tumor of bone, and hypercalcemia of malignancy. Bone metastases affect more than 330,000 patients in the U.S. annually, causing pain, fractures, and reduced quality of life. Aukelso works by targeting RANKL, limiting bone breakdown and helping protect skeletal health in patients with advanced cancer.

Patients should be aware of potential side effects, including fatigue, nausea, low phosphate levels, and hypocalcemia. Serious but less common reactions include osteonecrosis of the jaw, atypical fractures, and multiple vertebral fractures following treatment discontinuation. Doctors will monitor calcium levels closely and provide guidance on supplementation to minimize risks.

By providing a biosimilar alternative, Aukelso may expand access to effective bone-targeted therapies for patients with breast and prostate cancers, offering an important tool to manage cancer-related bone complications.

The Future of Bosaya and Aukelso

Both Bosaya and Aukelso represent an important advancement in cancer and osteoporosis care. Overall, the news release emphasizes that these biosimilars may provide cost-effective options without compromising efficacy or safety. For patients undergoing cancer treatments that impact bone health, these new options offer the potential to reduce fracture risk and maintain quality of life, highlighting the evolving landscape of supportive care in oncology.

References

1. “Biocon Biologics Receives U.S. Food and Drug Administration Approval for Bosaya and Aukelso, Denosumab Biosimilars,” by Biocon Biologics Ltd. (BBL). News release; Sept. 17, 2025.
2. “Biosimilar Medicines,” by American Cancer Society. https://www.cancer.org/cancer/managing-cancer/treatment-types/biosimilar-drugs.html

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