FDA Approves Another Pair of Denosumab Biosimilars, Conexxence and Bomyntra

The FDA approved another set of denosumab biosimilars, Conexxence/Bomyntra (denosumab-bnht) expanding treatment options for osteoporosis, bone metastases, and other bone-related conditions, amidst a flurry of similar approvals and legal settlements. | Image Credit: gguy - stock.adobe.com

The FDA has approved Fresenius Kabi Biopharma's denosumab biosimilars, Conexxence and Bomyntra (denosumab-bnht), for all indications of the reference products Prolia and Xgeva, respectively, further expanding access to more affordable treatment options for patients with osteoporosis, bone metastases, and other bone-related conditions.¹

Fresenius Kabi Biopharma announced the approval of its Biologics License Application for both denosumab biosimilars and a global settlement with Amgen.

“This marks our sixth FDA biosimilar approval, expanding our portfolio to provide more affordable therapies to patients in the US,” Sang-Jin Pak, MD, president of Fresenius Kabi Biopharma, said.

In March 2024, the FDA granted approval to Wyost/Jubbonti (denosumab-bddz; GP2411), marking it as the first biosimilar to reference Xgeva/Prolia (denosumab) in the US.² A month ago, the FDA and the European Medicines Agency also approved another pair of biosimilars, Ospomyv/Xbryk (denosumab-dssb; SB16), referencing Prolia/Xgeva (denosumab).³ The FDA also approved Celltrion's denosumab biosimilars, Stoboclo and Osenvelt (denosumab-bmwo), earlier this month, again referencing Prolia and Xgeva, respectively.⁴

Two comparative clinical studies supported the newest approval, which was based on comprehensive analytical development and similarity assessment.¹ One study measured pharmacokinetic, pharmacodynamic (PD), and immunogenicity among healthy volunteers, and the second study measured efficacy, PD, safety, and immunogenicity in women with postmenopausal osteoporosis.

The FDA approved Conexxence (denosumab-bnht) for use in various adult patient populations at high risk for fractures, including osteoporosis, individuals undergoing certain cancer treatments that affect bone density, and patients receiving long-term glucocorticoid therapy. For dosage, clinicians administer a 60 mg/mL solution via a single-dose prefilled syringe.

Patients with postmenopausal osteoporosis experienced adverse events (AEs) including back pain, hypercholesterolemia, musculoskeletal pain, and cystitis. Men with osteoporosis experienced AEs such as back pain, arthralgia, and nasopharyngitis. Patients with glucocorticoid-induced osteoporosis commonly experienced AEs such as back pain, hypertension, bronchitis, and headache. Those with hormone ablation for cancer most commonly experienced AEs of arthralgia and back pain in patients with bone loss.

The FDA approved Bomyntra (denosumab-bnht) to prevent skeletal-related events in adult patients with multiple myeloma and bone metastases from solid tumors. The FDA also approved it to treat hypercalcemia of malignancy refractory to bisphosphonate therapy and giant cell tumor of bone in adults and skeletally mature adolescents.

Patients receive the approved dosage as a 120 mg/1.7 mL solution via single-dose vial or prefilled syringe. Those with bone metastasis from solid tumors commonly experienced fatigue/asthenia, hypophosphatemia, and nausea. Patients with multiple myeloma reported diarrhea, nausea, anemia, back pain, thrombocytopenia, peripheral edema, hypocalcemia, upper respiratory tract infection, rash, and headache.

Patients with giant cell tumor of bone experienced arthralgia, headache, nausea, back pain, fatigue, and pain in extremity. Finally, patients with hypercalcemia of malignancy experienced nausea, dyspnea, decreased appetite, headache, peripheral edema, vomiting, anemia, constipation, and diarrhea.

Fresenius Kabi Biopharma plans to launch the denosumab biosimilars in the US market mid-2025 and in Europe in the second half of 2025, pending regulatory approvals.

References

1. Fresenius receives FDA approval for their denosumab biosimilars and secures global settlement agreement. News release. Business Wire; March 27, 2025. Accessed March 27, 2025. https://www.businesswire.com/news/home/20250327908783/en/Fresenius-Receives-FDA-Approval-for-their-Denosumab-Biosimilars-and-Secures-Global-Settlement-Agreement

2. Jeremias S. FDA approves first denosumab biosimilars. The Center for Biosimilars^®. March 5, 2024. Accessed March 27, 2025. https://www.centerforbiosimilars.com/view/fda-approves-first-denosumab-biosimilar

3. Jeremias S. FDA, EMA approve second pair of denosumab biosimilars. The Center for Biosimilars. February 17, 2025. Accessed March 27, 2025. https://www.centerforbiosimilars.com/view/fda-ema-approve-second-pair-of-denosumab-biosimilars

4. Santoro C. FDA approves denosumab biosimilars Stoboclo and Osenvelt. AJMC^®. March 4, 2025. Accessed March 27, 2025. https://www.ajmc.com/view/fda-approves-denosumab-biosimilars-stoboclo-and-osenvelt