[Show abstract][Hide abstract] ABSTRACT: Odanacatib is a cathepsin K inhibitor investigated for the treatment of postmenopausal osteoporosis. Phase 2 data indicate that 50 mg once weekly inhibits bone resorption and increases bone mineral density, with only a transient decrease in bone formation. We describe the background, design and participant characteristics for the phase 3 registration trial.
Odanacatib (ODN) is a selective cathepsin K inhibitor being evaluated for the treatment of osteoporosis. In a phase 2 trial, ODN 50 mg once weekly reduced bone resorption while preserving bone formation and progressively increased BMD over 5 years. We describe the phase III Long-Term ODN Fracture Trial (LOFT), an event-driven, randomized, blinded placebo-controlled trial, with preplanned interim analyses to permit early termination if significant fracture risk reduction was demonstrated. An extension was planned, with participants remaining on their randomized treatment for up to 5 years, then transitioning to open-label ODN.
The three primary outcomes were radiologically determined vertebral, hip, and clinical non-vertebral fractures. Secondary end points included clinical vertebral fractures, BMD, bone turnover markers, and safety and tolerability, including bone histology. Participants were women, 65 years or older, with a BMD T-score ≤-2.5 at the total hip (TH) or femoral neck (FN) or with a prior radiographic vertebral fracture and a T-score ≤-1.5 at the TH or FN. They were randomized to ODN or placebo tablets. All received weekly vitamin D3 (5600 international units (IU)) and daily calcium supplements as needed to ensure a daily intake of approximately 1200 mg.
Altogether, 16,713 participants were randomized at 387 centers. After a planned interim analysis, an independent data monitoring committee recommended that the study be stopped early due to robust efficacy and a favorable benefit/risk profile. Following the base study closeout, 8256 participants entered the study extension.
This report details the background and study design of this fracture end point trial and describes the baseline characteristics of its participants.
Osteoporosis International 11/2014; 26(2). DOI:10.1007/s00198-014-2944-6 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Context:Odanacatib, a cathepsin K inhibitor, increases spine and hip areal bone mineral density (BMD) in postmenopausal women with low BMD and cortical thickness in ovariectomized monkeys.Objective:The objective of the study was to examine the impact of odanacatib on the trabecular and cortical bone compartments and estimated strength at the hip and spine.Design:This was a randomized, double-blind, 2-year trial.Setting:The study was conducted at a private or institutional practice.Participants:Participants included 214 postmenopausal women with low areal BMD.Intervention:The intervention included odanacatib 50 mg or placebo weekly.Main Outcome Measures:Changes in areal BMD by dual-energy x-ray absorptiometry (primary end point, 1 year areal BMD change at lumbar spine), bone turnover markers, volumetric BMD by quantitative computed tomography (QCT), and bone strength estimated by finite element analysis were measured.Results:Year 1 lumbar spine areal BMD percent change from baseline was 3.5% greater with odanacatib than placebo (P < .001). Bone-resorption marker C-telopeptide of type 1 collagen was significantly lower with odanacatib vs placebo at 6 months and 2 years (P < .001). Bone-formation marker procollagen I N-terminal peptide initially decreased with odanacatib but by 2 years did not differ from placebo. After 6 months, odanacatib-treated women had greater increases in trabecular volumetric BMD and estimated compressive strength at the spine and integral and trabecular volumetric BMD and estimated strength at the hip (P < .001). At the cortical envelope of the femoral neck, bone mineral content, thickness, volume, and cross-sectional area also increased from baseline with odanacatib vs placebo (P < .001 at 24 months). Adverse experiences were similar between groups.Conclusions:Over 2 years, odanacatib decreased bone resorption, maintained bone formation, increased areal and volumetric BMD, and increased estimated bone strength at both the hip and spine.
The Journal of Clinical Endocrinology and Metabolism 01/2013; 98(2). DOI:10.1210/jc.2012-2972 · 6.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The selective cathepsin K inhibitor odanacatib (ODN) progressively increased bone mineral density (BMD) and decreased bone-resorption markers during 2 years of treatment in postmenopausal women with low BMD. A 1-year extension study further assessed ODN efficacy and safety and the effects of discontinuing therapy. In the base study, postmenopausal women with BMD T-scores between -2.0 and -3.5 at the lumbar spine or femur received placebo or ODN 3, 10, 25, or 50 mg weekly. After 2 years, patients (n = 189) were rerandomized to ODN 50 mg weekly or placebo for an additional year. Endpoints included BMD at the lumbar spine (primary), total hip, and hip subregions; levels of bone turnover markers; and safety assessments. Continued treatment with 50 mg of ODN for 3 years produced significant increases from baseline and from year 2 in BMD at the spine (7.9% and 2.3%) and total hip (5.8% and 2.4%). Urine cross-linked N-telopeptide of type I collagen (NTx) remained suppressed at year 3 (-50.5%), but bone-specific alkaline phosphatase (BSAP) was relatively unchanged from baseline. Treatment discontinuation resulted in bone loss at all sites, but BMD remained at or above baseline. After ODN discontinuation at month 24, bone turnover markers increased transiently above baseline, but this increase largely resolved by month 36. There were similar overall adverse-event rates in both treatment groups. It is concluded that 3 years of ODN treatment resulted in progressive increases in BMD and was generally well tolerated. Bone-resorption markers remained suppressed, whereas bone-formation markers returned to near baseline. ODN effects were reversible: bone resorption increased transiently and BMD decreased following treatment discontinuation.
Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 02/2011; 26(2):242-51. DOI:10.1002/jbmr.212 · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cathepsin K, a cysteine protease expressed in osteoclasts, degrades type 1 collagen. Odanacatib selectively and reversibly inhibited cathepsin K and rapidly decreased bone resorption in preclinical and phase I studies. A 1-year dose-finding trial with a 1-year extension on the same treatment assignment was performed in postmenopausal women with low bone mineral density (BMD) to evaluate the safety and efficacy of weekly doses of placebo or 3, 10, 25, or 50 mg of odanacatib on BMD and biomarkers of skeletal remodeling. Women with BMD T-scores of -2.0 or less but not less than -3.5 at the lumbar spine or femoral sites were randomly assigned to receive placebo or one of four doses of odanacatib; all received vitamin D with calcium supplementation as needed. The primary endpoint was percentage change from baseline lumbar spine BMD. Other endpoints included percentage change in BMD at hip and forearm sites, as well as changes in biomarkers of skeletal remodeling. Twenty-four months of treatment produced progressive dose-related increases in BMD. With the 50-mg dose of odanacatib, lumbar spine and total-hip BMD increased 5.5% and 3.2%, respectively, whereas BMD at these sites was essentially unchanged with placebo (-0.2% and -0.9%). Biochemical markers of bone turnover exhibited dose-related changes. The safety and tolerability of odanacatib generally were similar to those of placebo, with no dose-related trends in any adverse experiences. In summary, 2 years of weekly odanacatib treatment was generally well-tolerated and increased lumbar spine and total-hip BMD in a dose-related manner in postmenopausal women with low BMD.
Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 10/2009; 25(5):937-47. DOI:10.1359/jbmr.091035 · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Glucocorticoid-induced osteoporosis is the most common iatrogenic form of osteoporosis. We evaluated the efficacy and safety of once-weekly bisphosphonate therapy for prevention and treatment of bone loss in patients on glucocorticoid therapy.
We conducted a 12-month, multicenter, randomized, double-blind, placebo-controlled trial with 114 and 59 patients in the treatment and placebo arms, respectively. Participants were stratified according to the duration of prior oral glucocorticoid therapy at randomization. Participants received alendronate 70 mg once weekly (ALN OW) or placebo; all received supplemental daily calcium (1000 mg) and 400 IU vitamin D. Clinical evaluations were performed at baseline, 3, 6, 9, and 12 months.
At 12 months, there was a significant mean percentage increase from baseline in the ALN OW group for lumbar spine (2.45%), trochanter (1.27%), total hip (0.75%), and total body (1.70%) bone mineral density (BMD). Comparing ALN OW versus placebo at 12 months, a significant treatment difference for the mean percentage change from baseline was observed for lumbar spine (treatment difference of 2.92%; p </= 0.001), trochanter (treatment difference 1.66%; p = 0.007), and total hip (treatment difference 1.19; p = 0.008) BMD. Biochemical markers of bone remodeling also showed significant mean percentage decreases from baseline.
Over 12 months ALN OW significantly increased lumbar spine, trochanter, total hip, and total body BMD compared with baseline among patients taking glucocorticoid therapy. A significant treatment difference versus placebo was observed at 12 months for the mean percentage change from baseline for lumbar spine, trochanter, and total hip.
The Journal of Rheumatology 06/2009; 36(8):1705-14. DOI:10.3899/jrheum.081207 · 3.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To compare alendronate 70 mg once weekly (OW) with risedronate 35 mg OW with respect to change in bone mineral density (BMD), biochemical markers and upper gastrointestinal (UGI) tolerability over 24 months.
This was a 12-month extension to the Fosamax Actonel Comparison Trial international study (FACTS). Postmenopausal women with osteoporosis randomly assigned to either alendronate 70 mg OW or risedronate 35 mg OW for the 12-month base study continued taking the same double-blind study medication. Efficacy measurements were BMD at the hip trochanter, lumbar spine, total hip, and femoral neck and levels of four bone turnover markers at 24 months. The primary hypothesis was that alendronate would produce a greater mean per cent increase from baseline in hip trochanter BMD at 24 months.
Trochanter BMD increased significantly from baseline to month 24 in both groups, with a significantly larger increase with alendronate: adjusted mean treatment difference of 1.50% (95% confidence interval: 0.74%, 2.26%; p < 0.001). Similar results were seen at all BMD sites. Significant geometric mean per cent decreases (p < 0.001) from baseline were seen for all four bone turnover markers in both groups, with significantly larger decreases (p < 0.001) with alendronate: adjusted mean treatment differences ranged from 8.9% to 25.3%. No significant differences were seen in incidence of UGI or other adverse events.
Alendronate 70 mg OW yielded significantly greater BMD gains and larger decreases in bone turnover marker levels than risedronate 35 mg OW over 24 months, with no difference in UGI tolerability.
International Journal of Clinical Practice 05/2008; 62(4):575-84. DOI:10.1111/j.1742-1241.2008.01704.x · 2.57 Impact Factor