CLINICAL STUDIES
Treatment of Postmenopausal Osteoporosis
Study 1 : The efficacy and safety of Reclast in the treatment of postmenopausal osteoporosis was demonstrated in Study 1, a randomized, double-blind, placebo-controlled, multinational study of 7736 women aged 65-89 years (mean age of 73) with either: a femoral neck BMD T-score less than or equal to -1.5 and at least two mild or one moderate existing vertebral fracture(s); or a femoral neck BMD T-score less than or equal to -2.5 with or without evidence of an existing vertebral fracture(s). Women were stratified into two groups: Stratum I: no concomitant use of osteoporosis therapy or Stratum II: baseline concomitant use of osteoporosis therapies which included calcitonin, raloxifene, tamoxifen, hormone replacement therapy; but excluded other bisphosphonates.
Women enrolled in Stratum I (n= 5661) were evaluated annually for incidence of vertebral fractures. All women (Strata I and II) were evaluated for the incidence of hip and other clinical fractures. Reclast was administered once a year for three consecutive years, as a single 5 mg dose in 100 mL solution infused over at least 15 minutes, for a total of three doses. All women received 1000 to 1500 mg of elemental calcium plus 400 to 1200 IU of vitamin D supplementation per day.
The two primary efficacy variables were the incidence of morphometric vertebral fractures at 3 years and the incidence of hip fractures over a median duration of 3 years. The diagnosis of an incident vertebral fracture was based on both qualitative diagnosis by the radiologist and quantitative morphometric criterion. The morphometric criterion required the dual occurrence of 2 events: a relative height ratio or relative height reduction in a vertebral body of at least 20%, together with at least a 4 mm absolute decrease in height.
Effect on Vertebral Fractures
Reclast significantly decreased the incidence of new vertebral fractures at one, two, and three years as shown in Table 4.
Table 4. Proportion of Patients with New Morphometric Vertebral Fractures Outcome | Reclast (%) | Placebo (%) | Absolute Reduction in Fracture Incidence % (95% CI) | Relative Reduction in Fracture Incidence % (95% CI) |
At least one new vertebral fracture (0–1 year) | 1.5 | 3.7 | 2.2 (1.4, 3.1) | 60 (43, 72)** |
At least one new vertebral fracture (0–2 years) | 2.2 | 7.7 | 5.5 (4.4, 6.6) | 71 (62, 78)** |
At least one new vertebral fracture (0–3 years) | 3.3 | 10.9 | 7.6 (6.3, 9.0) | 70 (62, 76)** |
** p <0.0001 |
The reductions in vertebral fractures over three years were consistent (including new/worsening and multiple vertebral fractures) and significantly greater than placebo regardless of age, geographical region, baseline body mass index, number of baseline vertebral fractures, femoral neck BMD T-score, or prior bisphosphonate usage.
Effect on Hip Fracture over 3 years
Reclast demonstrated a 1.1% absolute reduction and 41% relative reduction in the risk of hip fractures over a median duration of follow-up of 3 years. The hip fracture event rate was 1.4% for Reclast-treated patients compared to 2.5% for placebo-treated patients.
Figure 1. Cumulative Incidence of Hip Fracture Over 3 Years
The reductions in hip fractures over three years were greater for Reclast than placebo regardless of femoral neck BMD T-score.
Effect on All Clinical Fractures
Reclast demonstrated superiority to placebo in reducing the incidence of all clinical fractures, clinical (symptomatic) vertebral and non-vertebral fractures (excluding finger, toe, facial, and clinical thoracic and lumbar vertebral fractures). All clinical fractures were verified based on the radiographic and/or clinical evidence. A summary of results is presented in Table 5.
Table 5. Between –Treatment Comparisons of the Incidence of Clinical Fracture Variables Over 3 Years Outcome | Reclast (N= 3875) Event Rate n (%) + | Placebo (N= 3861) Event Rate n (%) + | Absolute Reduction in Fracture Incidence % (95% CI) + | Relative Risk Reduction in Fracture Incidence % (95% CI) |
Any clinical fracture (1) | 308 (8.4) | 456 (12.8) | 4.4 (3.0, 5.8) | 33 (23, 42)** |
Clinical vertebral fracture (2) | 19 (0.5) | 84 (2.6) | 2.1 (1.5, 2.7) | 77 (63, 86)** |
Non-vertebral fracture (3) | 292 (8.0) | 388 (10.7) | 2.7 (1.4, 4.0) | 25 (13, 36)* |
*p-value < 0.001, **p-value <0.0001 + Event rates based on Kaplan-Meier estimates at 36 months |
(1) Excluding finger, toe, and facial fractures |
(2) Includes clinical thoracic and clinical lumbar vertebral fractures (3) Excluding finger, toe, facial, and clinical thoracic and lumbar vertebral fractures |
Effect on Bone Mineral Density (BMD)
Reclast significantly increased BMD at the lumbar spine, total hip and femoral neck, relative to treatment with placebo at time points 12, 24, and 36 months. Treatment with Reclast resulted in a 6.7% increase in BMD at the lumbar spine, 6.0 % at the total hip, and 5.1% at the femoral neck, over 3 years as compared to placebo.
Bone Histology
Bone biopsy specimens were obtained between Months 33 and 36 from 82 postmenopausal patients with osteoporosis treated with 3 annual doses of Reclast. Of the biopsies obtained, 81 were adequate for qualitative histomorphometry assessment, 59 were adequate for partial quantitative histomorphometry assessment, and 38 were adequate for full quantitative histomorphometry assessment. Micro CT analysis was performed on 76 specimens. Qualitative, quantitative and micro CT assessments showed bone of normal architecture and quality without mineralization defects.
Effect on Height
In the 3-year osteoporosis study standing height was measured annually using a stadiometer. The Reclast group revealed less height loss compared to placebo (4.2 mm vs. 7.0 mm, respectively (p<0.001)).
Study 2 : The efficacy and safety of Reclast in the treatment of patients with osteoporosis who suffered a recent low-trauma hip fracture was demonstrated in Study 2, a randomized, double-blind, placebo-controlled, multinational endpoint study of 2127 men and women aged 50-95 years (mean age of 74.5). Concomitant osteoporosis therapies excluding other bisphosphonates and parathyroid hormone were allowed. Reclast was administered once a year as a single 5 mg dose in 100 mL solution, infused over at least 15 minutes. The study continued until at least 211 patients had confirmed clinical fractures in the study population. Vitamin D levels were not routinely measured but a loading dose of vitamin D (50,000 to 125,000 IU orally or IM) was given to patients and they were started on 1000 to 1500 mg of elemental calcium plus 800 to 1200 IU of vitamin D supplementation per day for at least 14 days prior to the study drug infusions. The primary efficacy variable was the incidence of clinical fractures over the duration of the study.
Reclast significantly reduced the incidence of any clinical fracture by 35%. There was also a 46% reduction in the risk of a clinical vertebral fracture.
Table 6. Between - Treatment Comparisons of the Incidence of Key Clinical Fracture Variables Outcome | Reclast (N=1065) Event Rate n (%) + | Placebo (N=1062) Event Rate n (%) + | Absolute Reduction in Fracture Incidence % (95% CI) + | Relative Risk Reduction in Fracture Incidence % (95% CI) |
Any clinical fracture (1) | 92 (8.6) | 139 (13.9) | 5.3 (2.3, 8.3) | 35 (16, 50)** |
Clinical vertebral fracture (2) | 21 (1.7) | 39 (3.8) | 2.1 (0.5, 3.7) | 46 (8, 68)* |
*p-value <0.05, **p-value <0.005 + Event rates based on Kaplan-Meier estimates at 24 months (1) Excluding finger, toe and facial fractures (2) Including clinical thoracic and clinical lumbar vertebral fractures |
Effect on Bone Mineral Density (BMD)
Reclast significantly increased BMD relative to placebo at the hip and femoral neck at all timepoints (12, 24, and 36 months). Treatment with Reclast resulted in a 6.4 % increase in BMD at the total hip and a 4.3% increase at the femoral neck over 36 months as compared to placebo.
14.2 Osteoporosis in Men
The efficacy and safety of Reclast in men with osteoporosis or significant osteoporosis secondary to hypogonadism, was assessed in a randomized, multicenter, double-blind, active controlled, study of 302 men aged 25-86 years (mean age of 64). The duration of the trial was two years. Patients were randomized to either Reclast which was administered once annually as a 5 mg dose in 100 mL infused over 15 minutes for a total of up to two doses, or to an oral weekly bisphosphonate (active control) for up to two years. All participants received 1000 mg of elemental calcium plus 800 to 1000 IU of vitamin D supplementation per day.
Effect on Bone Mineral Density (BMD)
An annual infusion of Reclast was non-inferior to the oral weekly bisphosphonate active control based on the percentage change in lumbar spine BMD at Month 24 relative to baseline (Reclast: 6.1% increase; active control: 6.2% increase).
14.3 Treatment and Prevention of Glucocorticoid - Induced Osteoporosis
The efficacy and safety of Reclast to prevent and treat glucocorticoid-induced osteoporosis (GIO) was assessed in a randomized, multicenter, double-blind, stratified, active controlled study of 833 men and women aged 18-85 years (mean age of 54.4 years) treated with > 7.5 mg/day oral prednisone (or equivalent). Patients were stratified according to the duration of their pre-study corticosteroid therapy: < 3 months prior to randomization (prevention subpopulation), and > 3 months prior to randomization (treatment subpopulation). The duration of the trial was one year. Patients were randomized to either Reclast which was administered once as a 5 mg dose in 100 mL infused over 15 minutes, or to an oral daily bisphosphonate (active control) for one year. All participants received 1000 mg of elemental calcium plus 400 to 1000 IU of vitamin D supplementation per day.
Effect on Bone Mineral Density (BMD)
In the GIO treatment subpopulation, Reclast demonstrated a significant mean increase in lumbar spine BMD compared to the active control at one year (Reclast 4.1%, active control 2.7%) with a treatment difference of 1.4% (p<0.001). In the GIO prevention subpopulation, Reclast demonstrated a significant mean increase in lumbar spine BMD compared to active control at one year (Reclast 2.6%, active control 0.6%) with a treatment difference of 2.0% (p<0.001).
Bone Histology
Bone biopsy specimens were obtained from 23 patients (12 in the Reclast treatment group and 11 in the active control treatment group) at Month 12 treated with an annual dose of Reclast or daily oral active control. Qualitative assessments showed bone of normal architecture and quality without mineralization defects. Apparent reductions in activation frequency and remodeling rates were seen when compared with the histomorphometry results seen with Reclast in the postmenopausal osteoporosis population. The long-term consequences of this degree of suppression of bone remodeling in glucocorticoid-treated patients is unknown.
4 Treatment of Paget’s Disease of Bone
Reclast was studied in male and female patients with moderate to severe Paget’s disease of bone, defined as serum alkaline phosphatase level at least twice the upper limit of the age-specific normal reference range at the time of study entry. Diagnosis was confirmed by radiographic evidence.
The efficacy of one infusion of 5 mg Reclast vs. oral daily doses of 30 mg risedronate for 2 months was demonstrated in two identically designed 6-month randomized, double blind trials. The mean age of patients in the two trials was 70. Ninety-three percent (93%) of patients were Caucasian. Therapeutic response was defined as either normalization of serum alkaline phosphatase (SAP) or a reduction of at least 75% from baseline in total SAP excess at the end of 6 months. SAP excess was defined as the difference between the measured level and midpoint of normal range.
In both trials Reclast demonstrated a superior and more rapid therapeutic response compared with risedronate and returned more patients to normal levels of bone turnover, as evidenced by biochemical markers of formation (SAP, serum N-terminal propeptide of type I collagen [P1NP]) and resorption (serum CTx 1 [cross-linked C-telopeptides of type I collagen] and urine α-CTx).
The 6-month combined data from both trials showed that 96% (169/176) of Reclast-treated patients achieved a therapeutic response as compared with 74% (127/171) of patients treated with risedronate. Most Reclast patients achieved a therapeutic response by the Day 63 visit. In addition, at 6 months, 89% (156/176) of Reclast-treated patients achieved normalization of SAP levels, compared to 58% (99/171) of patients treated with risedronate (p<0.0001) (see Figure 2).
Figure 2. Therapeutic Response/Serum Alkaline Phosphatase (SAP) Normalization Over Time
The therapeutic response to Reclast was similar across demographic and disease-severity groups defined by gender, age, previous bisphosphonate use, and disease severity. At 6 months, the percentage of Reclast-treated patients who achieved therapeutic response was 97% and 95%, respectively, in each of the baseline disease severity subgroups (baseline SAP < 3xULN, > 3xULN) compared to 75% and 74%, respectively, for the same disease severity subgroups of risedronate-treated patients.
In patients who had previously received treatment with oral bisphosphonates, therapeutic response rates were 96% and 55% for Reclast and risedronate, respectively. The comparatively low risedronate response was due to the low response rate (7/23, 30%) in patients previously treated with risedronate. In patients naïve to previous treatment, a greater therapeutic response was also observed with Reclast (98%) relative to risedronate (86%). In patients with symptomatic pain at screening, therapeutic response rates were 94% and 70% for Reclast and risedronate respectively. For patients without pain at screening, therapeutic response rates were 100% and 82% for Reclast and risedronate respectively.
Bone histology was evaluated in 7 patients with Paget’s disease 6 months after being treated with Reclast 5 mg. Bone biopsy results showed bone of normal quality with no evidence of impaired bone remodeling and no evidence of mineralization defect.
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