Loading...
A phase 2 study of MK-5442, a calcium-sensing receptor antagonist, in postmenopausal women with osteoporosis after long-term use of oral bisphosphonates
Cosman, F. Gilchrist, N. McClung, Michael R. Foldes, J. de Villiers, T. Santora, A. Leung, A. T. Samanta, S. Heyden, N. McGinnis, J.P.
Cosman, F.
Gilchrist, N.
McClung, Michael R.
Foldes, J.
de Villiers, T.
Santora, A.
Leung, A. T.
Samanta, S.
Heyden, N.
McGinnis, J.P.
Abstract
Summary: In women with osteoporosis treated with alendronate for > 12 months and oral bisphosphonates for > 3 of the last 4 years, switching to MK-5442, a calcium receptor antagonist, stimulated endogenous parathyroid hormone (PTH) secretion and increased bone turnover marker levels, but produced a decline in bone mineral density (BMD) at all sites. Introduction: This study assessed the effects of switching from long-term oral bisphosphonate therapy to the calcium-sensing receptor antagonist MK-5442 on BMD and bone turnover markers (BTMs) in post-menopausal women with osteoporosis. Methods: This randomized, active and placebo-controlled, dose-ranging study enrolled 526 postmenopausal women, who had taken alendronate (ALN) for ≥12 months preceding the trial and any oral bisphosphonate for ≥3 of the preceding 4 years and had spine or hip BMD T-scores ≤−2.5 or ≤−1.5 with ≥1 prior fragility fracture. Women were randomized to continue ALN 70 mg weekly or switch to MK-5442 (5, 7.5, 10, or 15 mg daily) or placebo. Results: Switching from ALN to MK-5442 produced a dose-dependent parathyroid hormone (PTH) pulse of threefold to sixfold above baseline at 1 h, with PTH levels that remained twofold to threefold above baseline at 4 h and returned to baseline by 24 h. Switching to MK-5442 or placebo increased BTM levels compared to baseline within 3 months and MK-5442 10 mg increased BTM levels compared to placebo by 6 months. With all MK-5442 doses and placebo, spine and hip BMD declined from baseline, and at 12 months, BMD levels were below those who continued ALN (all groups P < 0.05 vs ALN). There was also a dose-dependent increase in the incidence of hypercalcemia with MK-5442. Conclusion: Switching from ALN to MK-5442 resulted in a pulsatile increase in PTH and increases in BTMs, but a decline in BMD compared with continued ALN. MK-5442 is not a viable option for the treatment of osteoporosis.
Keywords
bisphosphonate, calcium-sensing receptor antagonist, osteoporosis, postmenopausal, pth, randomized clinical trial
Date
2016
Type
Journal article
Journal
Osteoporosis International
Book
Volume
27
Issue
1
Page Range
377-386
Article Number
ACU Department
Mary MacKillop Institute for Health Research
Faculty of Health Sciences
Faculty of Health Sciences
Collections
Relation URI
Source URL
Event URL
Open Access Status
License
File Access
Controlled