Abstract 2139: Bone Mineral Density Gains with Monthly Oral Ibandronate (150mg) and Weekly Oral Alendronate (70mg) After 12 months: Results from the MOTION Study
Assil Saleh, M.D.
Authors:
E. Michael Lewiecki, Robert R. Recker, Farhad Sedarati, Colin Neate, Paul D. Miller
Background:
Bisphosphonates represent standard first-line treatment for osteoporosis. They act through antiresorptive mechanisms affecting bone remodeling and ultimately promote increased bone mineral density (BMD) and reduced fracture risk. Numerous approved agents are available with varying dosing regimens, relative potencies in increasing BMD and reducing fracture risk, as well as tolerability profiles. Oral monthly ibandronate (150mg) was shown in a Phase III randomized clinical trial to be as safe and effective as oral daily ibandronate in increasing lumbar spine and proximal femoral BMD in women with postmenopausal osteoporosis. No direct data on fracture incidence with the monthly dosing regimen are available; therefore, change in BMD is considered an acceptable surrogate marker for reduced fracture risk. Weekly alendronate (dosed at 70mg) has been previously shown to be as effective as daily dosing (10mg) in increasing BMD and decreasing fracture rates.
The MOTION trial (Monthly Oral Therapy with Ibandronate for Osteoporosis INtervention) is a non-inferiority trial comparing the efficacy and safety of once-monthly oral ibandronate with weekly oral alendronate.
Methods:
MOTION enrolled 1,760 postmenopausal women with osteoporosis in this international, multi-center, double-blind trial. Of these total subjects, 887 were randomized to monthly oral ibandronate (150mg) with weekly placebo, and 873 were randomized to weekly oral alendronate (70mg) and monthly placebo. Calcium and vitamin D supplements were administered to all patients. Non-inferiority of ibandronate versus alendronate was the study’s primary endpoint. The metric to determine non-inferiority of these therapies was the relative change in mean BMD of the lumbar spine and total hip at 12 months compared to baseline.
Results:
Published in: Lewieckia et al. Curr Med Res Opin. 2007; 26 (epub ).
At 12 months of follow up, mean lumbar spine BMD was 5.10% higher than baseline in the ibandronate group, and 5.78% higher than baseline in the alendronate group. The difference in the change in mean lumbar spine BMD was significant to satisfy non-inferiority of ibandronate. Likewise, mean total hip BMD was 2.94% higher than baseline in the ibandronate group, and 3.03% higher than baseline in the alendronate group. The difference in the change in mean total hip BMD was significant to satisfy non-inferiority criteria.
Conclusion:
Monthly oral ibandronate (150mg) is equally effective as weekly oral alendronate (70mg) in increasing BMD at the lumbar spine and total hip.
Editorial Comment:
Adherence to bisphosphonate therapy has been a well recognized limitation of these agents. Discontinuation rates of ~40% within 6 months of therapy have been reported with these agents, due to both their adverse effect profiles but also their stringent dosing requirements. Adherence, and ultimately fracture-associated morbidity, would be expected to improve if bisphosphonates could be dosed less frequently. This study is the first head-to-head, randomized controlled trial comparing monthly ibandronate to weekly alendronate, and its results support the thesis that monthly ibandronate is as effective as weekly alendronate in improving BMD at the spine and the total hip. Stronger support for the widespread use of ibandronate could come from further study, including an investigation of the fracture incidence in these treatment groups.
Although not appearing in this poster, data from MOTION on the tolerability and safety of monthly oral ibandronate compared to weekly alendronate were presented in poster 1545 (Emkey et al.) This particular study’s conclusion was that both treatment modalities are similarly well tolerated in this group of postmenopausal women with osteoporosis.
MOTION is an elegant next step in the continued evolution of effective, safe, well-tolerated and easily dosed therapies for osteoporosis.
