Romosozumab improves low bone mineral density in a postmenopausal woman undergoing chronic hemodialysis and treated with a calcium-sensing receptor agonist

Preventing osteoporotic fractures is an issue requiring urgent attention to reduce mortality. However, unlike chronic kidney disease-mineral and bone disorder (CKD-MBD), osteoporosis is inadequately addressed in patients undergoing chronic dialysis. In fact, little is known about the proper use of anti-osteoporotic drugs for patients with CKD-MBD. A recent study showed that romosozumab, an anti-osteoporotic drug, increased bone mineral density in osteoporotic patients on hemodialysis without clinically significant adverse events. However, the efficacy and safety of coadministering romosozumab with a calcium-sensing receptor (CaSR) agonist, a pivotal drug used in the management of CKD-MBD, remain unclear. Here, we report the case of a postmenopausal woman undergoing chronic hemodialysis and treated with add-on romosozumab for osteoporosis to CaSR agonist for secondary hyperparathyroidism. After 1 year of treatment, her bone mineral density increased; however, hypocalcemia occurred during the treatment. These results suggest that the concomitant use of romosozumab with CaSR agonist may be a possible treatment option for severe osteoporosis in postmenopausal women receiving chronic hemodialysis with a high fracture risk, but serum calcium levels should be monitored closely and those at risk of ectopic calcification might not be ideal candidates for such treatment.