To characterize the effects of discontinuation of denosumab therapy on variables of bone histology in postmenopausal women with low bone mass or osteoporosis. Patients who have received denosumab and completed study 20050179 (NCT00293813), completed study 20050141 (NCT00330460), completed study 20060237 (NCT00515463), completed study 20030216 (NCT00089791) but did not enroll in study 20060289 (NCT00523341) will be included in this study. Patients who will participate in the off-treatment imaging study for 20080747 (NCT00890981) are also eligible.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
SUPPORTIVE_CARE
Masking
NONE
Enrollment
15
Participants who had previously received denosumab received a transiliac crest bone biopsy performed following standard labeling procedures with tetracycline or tetracycline derivative.
Number of Participants With Normal/Abnormal Bone Histology
The number of participants with normal/abnormal bone histology as assessed by bone biopsy samples at the central histomorphometric facility. Normal bone histology is characterized by: - normal lamellar bone, - normal mineralization or - osteoid (the organic matrix of bone; young bone that has not undergone calcification). Biopsies with abnormal bone histology are characterized by: - osteomalacia, - marrow fibrosis, - clinically significant marrow abnormality or - woven bone.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Cancellous Bone Volume
Cancellous (trabecular) bone volume (Tb.V) is the relative volume of total cancellous bone measured (TV), expressed as percentage, that is occupied by trabeculae. Cancellous bone volume was measured using Fluorochrome labeling with tetracyclene and tartrate-resistant acid phosphatase stain (TRAP) staining techniques.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Trabecular Number
Trabecular number (Tb.N) is the number of trabeculae present per lineal mm and is calculated as trabecular bone volume/trabecular thickness. Tb.N is a measure of trabecular connectivity and decreases with bone loss.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Trabecular Separation
Trabecular separation (Tb.Sp) is the mean distance in mm between trabeculae (measured by integrated computer graphics). Tb.Sp increases with trabecular bone loss.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Trabecular Thickness
Mean trabecular thickness (Tb.Th) is a measure of trabecular structure and is calculated as the reciprocal of total bone (trabecular) surfaces. Tb.Th is reduced by aging and osteoporosis.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Cortical Width
Cortical width correlates with dual photon absorptiometric (DPX) measurements of bone density.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Surface Density
Surface density is calculated by total bone (trabecular) surfaces / total tissue volume.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Osteoblast - Osteoid Interface
Osteoblast - osteoid interface is calculated as osteoblast surface / osteoid surface \* 100.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Osteoid Surface
Osteoid surface is expressed as a percentage total bone surface.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Osteoid Width
Osteoid thickness (width; O.Th) is the mean thickness of osteoid seams on cancellous surfaces. O.Th is normally \<12.5 µm. Increased O.Th suggests abnormal mineralization (osteomalacia).
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Wall Thickness
Wall thickness is the average thickness of trabecular bone structural units (BSU) and is used to assess the overall balance between resorption and formation.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Eroded Surface/Bone Surface
Eroded surface is expressed as a percentage of total bone surface.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Osteoclast Number - Length Based
Osteoclast number expressed per mm of bone. Osteoclast number was measured using fluorochrome labeling with tetracyclene and tartrate-resistant acid phosphatase stain (TRAP) staining techniques.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Osteoclast Number - Surface Based
Osteoclast number expressed per bone surface area. Osteoclast number was measured using fluorochrome labeling with tetracyclene and tartrate-resistant acid phosphatase stain (TRAP) staining techniques.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Single-label Surface
Single-label surface is expressed as a percentage of total bone surface. The presence of a single label indicates that mineralization was occurring during only one labeling period.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Double-label Surface
Double-label surface is expressed as a percentage of total bone surface. The presence of double labels indicates that normal bone mineralization was actively occurring over the labeling interval.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Total Mineralizing Surface
Total mineralizing surfaces (MS) include all double and half of single-labeled surfaces. MS is expressed as a percentage of total bone surface.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Mineral Apposition Rate
The mineral apposition rate (MAR) is the avarage rate at which new bone mineral is being added on any actively forming surface. MAR is calculated as the average distance between visible labels, divided by the labeling interval.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Adjusted Mineral Apposition Rate
The mineral apposition rate (MAR) is the avarage rate at which new bone mineral is being added on any actively forming surface. Adjusted MAR is calculated as: (average distance between visible labels / labeling interval) \* (total mineralizing surface/total bone surface).
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Bone Formation Rate - Surface Based
Bone formation rate - surface based (BFR/BS) is the calculated rate at which cancellous bone surface is being replaced annually. BFR/BS is derived from the Mineral Appositional Rate \* 365 \* (relative mineralizing surface /total bone surface).
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Bone Formation Rate - Volume Based
Bone formation rate - volume based (BFR/BV) is the calculated rate at which cancellous bone volume is being replaced annually. BFR/BV is derived from the Mineral Appositional Rate \* 365 \* (relative mineralizing surface / total bone volume).
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Formation Period
The formation period is the duration of an interval when a place on the bone surface is actively forming bone. The formation period is calculated as the wall width (thickness of new bone made in one cycle) divided by the mineral apposition rate.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Activation Frequency
The average time that it takes for a new remodeling cycle to begin on any point on a cancellous surface is called the activation frequency (Ac.f). Activation frequency is calculated as the bone formation rate / wall width.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Osteoid Volume
Osteoid volume is expressed as a percentage of total bone volume.
Time frame: 25-34 days post-Day 1
Bone Histomorphometry: Mineralization Lag Time
The mineralization lag time is the time interval between osteoid secretion and its subsequent mineralization, in days.
Time frame: 25-34 days post-Day 1
C-Telopeptide (CTX-1)
C-Telopeptide is a biochemical marker for bone turnover. Blood samples were drawn for assessment of CTX-1 levels on either Day 3 or Day 20, within 24 hours of the last dose of the respective tetracycline cycle.
Time frame: Day 3 or Day 20
Procollagen Type 1 N-terminal Peptide (P1NP)
Procollagen Type 1 N-terminal Peptide is a biochemical marker of bone turnover. Blood samples were drawn for assessment of P1NP levels on either Day 3 or Day 20, within 24 hours of the last dose of the respective tetracycline cycle.
Time frame: Day 3 or Day 20
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