Early changes in bone turnover and bone mineral density after discontinuation of long-term oral bisphosphonates: a post hoc analysis

This post hoc analysis of a randomized, double-blind study of postmenopausal women with osteoporosis found that there were early increases in bone turnover markers and decreases in bone mineral density after discontinuation of long-term alendronate. These findings might help guide treatment decisions, including monitoring after alendronate withdrawal.

INTRODUCTION

The short-term effects of discontinuing long-term bisphosphonates are poorly characterized. This post hoc analysis investigated 1-12-month changes in bone mineral density (BMD) and bone turnover markers (BTM) after alendronate (ALN) discontinuation.

METHODS

Data were from a randomized, double-blind trial of MK-5442 (calcium-sensing receptor antagonist) following oral bisphosphonates, with placebo and continued ALN controls ( ClinicalTrials.gov NCT00996801). Postmenopausal women with osteoporosis had received oral bisphosphonate (≥ 3-4 preceding years; ALN for the 12 months pre-screening), continuing on ALN 70 mg/week (n = 87) or placebo (n = 88).

RESULTS

At 12 months, least-squares mean percent changes from baseline BMD (placebo vs. ALN) were lumbar spine (LS): - 0.36 vs. 1.29, total hip: - 1.44 vs. 0.46, and femoral neck (FN): - 1.26 vs. - 0.08 (all P < 0.05). BTM levels increased by 1-3 months, to 12 months, with placebo vs. ALN (P < 0.001). FN BMD decline was greater in the placebo subgroup with higher urinary N-terminal cross-linked telopeptides of type I collagen/creatinine [uNTx/Cr] (P < 0.01), and higher serum N-terminal pro-peptide of type 1 collagen [P1NP] levels (P < 0.05), at baseline. There was a trend toward greater FN BMD loss with higher BTM levels at 3 and/or 6 months. Younger age and higher LS BMD at baseline were associated with greater LS BMD loss at 12 months (P = 0.04 and < 0.01, respectively); higher baseline FN BMD predicted greater FN BMD loss (P = 0.04).

CONCLUSION

Early changes in BTM levels and BMD were observed after discontinuation of long-term ALN. Further characterization of factors associated with patients' risk of bone loss upon bisphosphonate discontinuation is warranted.

Review of once-monthly oral ibandronate and the use thereof

An advisory board meeting of key opinion leaders was held in 2015 to discuss the clinical data on oral ibandronate in the treatment of postmenopausal osteoporosis. Boniva 150 mg (ibandronate) oral once-monthly is indicated for the treatment of osteoporosis in postmenopausal women, in order to reduce the risk of vertebral fractures.1