Effects of monthly intravenous ibandronate on bone mineral density and microstructure in patients with primary osteoporosis after teriparatide treatment: The MONUMENT study

Highlights

• The effects of sequential therapy with intravenous ibandronate (1 mg/month) after teriparatide treatment was investigated

• 66 patients who had undergone teriparatide treatment for 18.6 months received intravenous ibandronate for 12 months.

• The patients were evaluated using DXA, QUS, bone turnover markers, and HR-pQCT at baseline and 6 and 12 months.

• Ibandronate increased aBMD of the lumbar spine and hip and improved cortical bone microstructure of the radius and tibia

Abstract

Purpose

To investigate the effects of sequential therapy with monthly intravenous ibandronate on bone mineral density (BMD) and microstructure in patients with primary osteoporosis who received teriparatide treatment.

Methods

Sixty-six patients with primary osteoporosis who had undergone teriparatide treatment for more than 12 months (mean 18.6 months) received sequential therapy with 1 mg/month intravenous ibandronate for 12 months. The patients were evaluated using dual-energy X-ray absorptiometry (DXA), quantitative ultrasound, bone turnover markers, and high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline and 6 and 12 months after beginning administration.

Results

At 12 months after beginning sequential therapy, the bone resorption marker, tartrate-resistant acid phosphatase-5b, decreased by 39.5%, with 82.3% of the patients exhibiting levels within the normal limit. DXA revealed that the BMD of the lumbar spine increased by 3.2%, with 79.0% of the patients exhibiting a response, and 40.3% experiencing an increase in BMD over 5%. HR-pQCT revealed that the cortical thickness of the distal tibia was increased by 2.6%. The cortical area increased by 2.5%, and the buckling ratio (an index of cortical instability) decreased by 2.5%. Most parameters of the trabecular bone showed no significant changes. These changes in the cortical bone were observed in both the distal radius and tibia and appeared beginning 6 months after treatment initiation.

Conclusions

Sequential therapy with monthly intravenous ibandronate increased the BMD and improved the cortical bone microstructure of osteoporotic patients who had undergone teriparatide treatment.