Endocrine Abstracts

Purpose: Denosumab is a monoclonal antibody that prevents osteoclast development. The effect of denosumab in solid organ transplant recipients has been elucidated, but the effect of denosumab in hematopoietic stem cell transplantation recipients has not been studied yet. Thus, the aim of this study was to determine the effectiveness and safety of denosumab in hematopoietic stem cell transplantation recipients.

Methods: We retrospectively evaluated 27 patients with osteoporosis (8 males and 19 females, mean age 53.6 ± 12.8 years) following allogeneic hematopoietic stem cell transplantation. Patients were treated with denosumab every 6 months for 12 months. The period of time since previous transplantations ranged from 2 years to 14 years (mean: 5.1 ± 2.7 years). Osteoporosis was diagnosed using dual energy X-ray absorptiometry. Bone mineral density was evaluated for denosumab-treated patients in a 12-month interval after the first administration of denosumab.

Results: Significant increases in bone mineral density were observed in all measured skeletal sites: 4.39 ± 6.63% for the lumbar spine (P = 0.014), 3.11 ± 7.69% for the femoral neck (P = 0.048), and 1.97 ± 6.01% for the total hip (P = 0.138). The bone turnover marker serum cross-linked C-terminal telopeptide of type 1 collagen decreased at 12 months, without significance (−6.67 ± 31.57%, P = 0.58). No serious symptomatic hypocalcemia was observed. However, asymptomatic hypocalcemia was noted in 2 (7.4%) patients. Serious adverse drug reactions requiring drug discontinuation were not observed.

Conclusion: Denosumab was well tolerated. It improved bone mineral density of hematopoietic stem cell transplantation recipients.

Keywords: Denosumab; Hematopoietic stem cell transplantation; Bone density; Osteoporosis