Case Study: Reactivating the Anabolic Window — The Use of Romosozumab Alongside Denosumab in Two Female Patients with Severe Osteoporosis Post-Kidney Transplant

By
Simona Barbuto
Paolo Mastromauro
Guido Zavatta
Daniele Vetrano
Anna Mistretta
Nicolò Bisceglia
Giorgia Comai
Uberto Pagotto
Gaetano La Manna
Giuseppe Cianciolo
September 4, 2026

Frontiers In Endocrinology

Overview

This case study reports the use of romosozumab alongside denosumab in two female kidney transplant recipients with severe osteoporosis. Both patients exhibited increased bone mineral density at the lumbar spine without adverse effects on mineral metabolism or allograft function.

Background

Kidney transplant recipients are at high risk for osteoporosis and fractures due to various factors, including chronic kidney disease and immunosuppressive therapy. Current treatment options for osteoporosis in this population are limited, necessitating innovative approaches to improve bone health. Romosozumab, an anabolic agent, presents a potential therapeutic option, particularly in patients who do not respond adequately to denosumab alone.

Data Highlights

Patient	Bone Mineral Density Change (Lumbar Spine)	Fracture Events
Case 1	5.9%	No new vertebral fractures
Case 2	11.2%	No new vertebral fractures

Key Findings

Both patients had severe osteoporosis and elevated fracture risk despite denosumab treatment.
Romosozumab was administered at a dose of 210 mg monthly for 12 months.
Bone formation markers P1NP and BAP increased early in treatment.
Bone mineral density increased significantly at the lumbar spine.
No clinically significant hypocalcemia occurred during the treatment period.
Allograft function remained stable throughout the study.

Clinical Implications

Monitoring of bone mineral density and metabolic parameters is essential to ensure patient safety and treatment efficacy.

Conclusion

This case study reports that romosozumab was added to ongoing denosumab treatment in kidney transplant recipients, resulting in increased bone mineral density at the lumbar spine without adverse effects on mineral metabolism or graft function.