Abaloparatide Increases Lumbar Spine and Hip BMD in Japanese Patients With Osteoporosis: The Phase 3 ACTIVE-J Study

Effects of Abaloparatide on Bone Mineral Density in Proximal Femoral Regions Corresponding to Arthroplasty Gruen Zones: A Study of Postmenopausal Women with Osteoporosis

BACKGROUND

Low hip bone mineral density (BMD) in patients who undergo total hip arthroplasty (THA) increases the risk of periprosthetic fractures, implant instability, and other complications. Recently, emphasis has been placed on bone health optimization: treating low BMD prior to a planned orthopaedic implant procedure in an effort to normalize BMD and reduce the potential risk of future complications. Abaloparatide is a U.S. Food and Drug Administration-approved osteoanabolic agent for men and postmenopausal women with osteoporosis and a candidate drug for bone health optimization that, in addition to benefits at the spine, increases hip BMD and reduces nonvertebral fracture risk. We hypothesized that abaloparatide would improve BMD in proximal femoral regions surrounding a virtual THA stem.

METHODS

This post hoc analysis obtained dual x-ray absorptiometry (DXA) hip scans from 500 randomly selected postmenopausal women with osteoporosis from the Phase-3 Abaloparatide Comparator Trial in Vertebral Endpoints (ACTIVE, NCT01343004) study after 0, 6, and 18 months of abaloparatide (250 patients) or placebo (250 patients). Hip DXA scans underwent 3-dimensional (3D) modeling via 3D-Shaper, followed by virtual resection of the proximal femur and simulated placement of a tapered, flat-wedge hip stem that guided delineation of the Gruen zones that were fully (zones 1 and 7) or largely (zones 2 and 6) captured in the scanning region. Integral, cortical, and trabecular volumetric BMD, cortical thickness, and cortical surface BMD (the product of cortical volumetric BMD and cortical thickness) were determined for each zone.

RESULTS

Compared with placebo, the abaloparatide group showed greater increases in integral volumetric BMD in all zones at months 6 and 18; cortical surface BMD in zones 1, 6, and 7 at month 6; cortical thickness, cortical volumetric BMD, and cortical surface BMD in all zones at month 18; and trabecular volumetric BMD in zones 1 and 7 at months 6 and 18.

CONCLUSIONS

Abaloparatide increases BMD in proximal femoral regions that interact with and support femoral stems, suggesting that abaloparatide may have value for preoperative or potentially perioperative bone health optimization in patients with osteoporosis undergoing THA.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Safety and Efficacy of Abaloparatide on Postmenopausal Osteoporosis: A Systematic Review and Meta-analysis

PURPOSE

The aging of the population increases the incidence of postmenopausal osteoporosis, which threatens the health of elderly women. Abaloparatide is a synthetic peptide analogue of the human parathyroid hormone-related protein that has recently been approved for the treatment of postmenopausal osteoporosis. Its efficacy and safety have not been systematically evaluated. Therefore, studies on the efficacy and safety of abaloparatide could be of assistance in the clinical medication of postmenopausal osteoporosis. The aim of this study was to evaluate the clinical efficacy and safety of abaloparatide in postmenopausal osteoporosis.

METHODS

PubMed, Cochrane Library, EMBASE, and Web of Science databases were electronically searched from inception to July 6, 2023, for relevant randomized controlled trials. Two review authors independently conducted the study screening, quality assessment (based on the Risk of Bias Assessment Tool recommended in the Cochrane handbook), and data extraction. Outcome measures included bone mineral density (BMD), bone turnover and metabolic markers, incidence of fractures, and adverse events. Data analyses were processed by using Stata SE15.

FINDINGS

Ultimately, 8 randomized controlled trials, involving a total of 3705 postmenopausal women, were included. Meta-analysis showed that abaloparatide administration significantly increased the BMD of the lumbar vertebrae (standardized mean difference [SMD], 1.28 [95% CI, 0.81-1.76); I2 = 78.5%]), femoral neck (SMD, 0.70 [95% CI, 0.17-1.23; I2 = 75.7%]), and hip bone (SMD, 0.86 [95% CI, 0.53-1.20; I2 = 60.4%]) in postmenopausal women compared with the control group. Type I procollagen N-terminal propeptide, a bone formation marker, was also elevated after abaloparatide administration. The incidence of vertebral fracture was lower in the abaloparatide group than in the control group (risk ratio, 0.13; 95% CI, 0.06-0.26; I2 = 0%). There was no significant difference in the incidence of adverse events between the abaloparatide and the placebo groups (risk ratio, 1.03; 95% CI, 0.99-1.06; I2 = 0%).

IMPLICATIONS

Abaloparatide has a protective effect on women with postmenopausal osteoporosis. It could reduce their risk for vertebral fracture; increase their BMD of the lumbar spine, femoral neck, and hip; and alleviate symptoms and complications of postmenopausal osteoporosis with considerable safety. Limitations of this study include not searching the gray literature and not performing a subgroup analysis. PROSPERO Registration No.: CRD42022370944.

An Overlooked Medication-Induced Celiac Flare Complicating Treatment of Osteoporosis

Background/Objective

Celiac disease, an immune reaction to gluten causing nutrient malabsorption, and long-term glucocorticoid therapy adversely affect bone metabolism and increase fracture risk.

Case Report

A patient with long-standing celiac disease on a strict gluten-free diet and long-term glucocorticoid therapy status post kidney transplant for Sjögren syndrome-induced interstitial nephritis presented for management of osteoporosis. Initial evaluation was notable for secondary hyperparathyroidism, which resolved after switching to a gluten-free calcium citrate supplement. Given normal serum total alkaline phosphatase (ALP) and parathyroid hormone (PTH), she began treatment of osteoporosis with abaloparatide. Two months later, she reported abrupt onset of diarrhea with significant weight loss. Biochemical investigation revealed a threefold increase in serum ALP level. As a precaution, abaloparatide was suspended, yet symptoms persisted with elevated ALP and PTH levels. Endoscopy revealed a celiac flare. The clinic-based pharmacist found that her pharmacy had inadvertently dispensed prednisone tablets containing wheat starch. A switch to a gluten-free formulation led to rapid resolution of the diarrhea with weight regain. Serum ALP and PTH levels normalized, and abaloparatide was resumed without biochemical abnormalities.

Discussion

An unintended switch to a gluten-containing prednisone formulation resulted in uncontrolled celiac disease causing calcium malabsorption, secondary hyperparathyroidism, elevated ALP levels, and an interruption in osteoporosis therapy. Common supplements and drugs can be a hidden source of gluten. Collaboration with a clinic-based pharmacist enhances the detection and prevention of medication-induced adverse reactions.

Conclusion

This case highlights the importance of a careful review of gluten-containing medications and supplements in patients with celiac disease.

Nocebo-associated treatment discontinuation with subcutaneous anti-osteoporotic drugs. A systematic review and meta-analysis of placebo-arm dropouts in randomized-controlled trials

OBJECTIVE

Nocebo is a concept of therapeutics referring to unpleasant symptoms attributed by a patient to a drug, due to negative anticipation. Patients receiving oral anti-osteoporotic drugs in randomized controlled trials (RCT) can experience adverse events leading to dropout, implying that nocebo contributes to treatment discontinuation for these drugs. In this study we aim to investigate the nocebo effect of subcutaneous anti-osteoporotic drugs with a higher compliance rate than orally administered drugs.

STUDY DESIGN

We searched MEDLINE, EMBASE, SCOPUS, and Cochrane databases for double-blind trials investigating subcutaneous anti-osteoporotic drugs for osteoporosis (namely, denosumab, teriparatide, abaloparatide and romosozumab) published up to May 2023.

MAIN OUTCOME MEASURE

Dropouts due to reported adverse events in the placebo arms ("nocebo dropouts").

RESULTS

Data from 17 trials were extracted. Among 10,529 placebo-treated patients the pooled nocebo-dropout percentage was 3 % for denosumab (average: 0.03; 95 % CI: 0.01-0.05), 1 % for romosozumab (average: 0.01; 95 % CI: 0.00-0.03) and 6 % for teriparatide and abaloparatide (average: 0.06; 95 % CI: 0.05-0.07). Nocebo-dropouts were significantly higher in men than women (6 % vs. 3 %, respectively, p = 0.012), in older (mean age >68 years) than in younger patients (5 % vs. 1 %, respectively, p = 0.017) and in those with more severe osteoporosis (based on the percentage of participants with prior fragility-related fractures in the study cohort) compared with patients with no prior fracture history (4 % vs. 1 %, respectively, p = 0.046).

CONCLUSION

Nocebo responses may contribute to treatment discontinuation with subcutaneous anti-osteoporotic drugs in clinical practice. Higher nocebo-related dropout rates in the higher-risk RCT population (older patients, males, those with prior fractures) show that nocebo mechanisms have the potential to hinder therapeutic efforts to specific populations who would benefit most. Prospero registration number CRD42020212843.

Marked increase in bone mineral density with oral phosphate and calcitriol in tumour-induced osteomalacia

Patients with osteomalacia have a low bone mineral density (BMD) and are often misdiagnosed as osteoporosis. A marked increase in BMD is noticed following successful treatment of osteomalacia. The biochemical hallmark of tumour-induced osteomalacia (TIO) is hypophosphatemia. Patients with TIO often have severe hypophosphatemic osteomalacia and dual-energy X-ray absorptiometry may demonstrate low BMD. Surgical removal of the phosphatonin-secreting lesion restores serum phosphate, corrects osteomalacia and is associated with a dramatic increase in BMD. We report two patients with TIO and low BMD, who were treated with oral phosphate and calcitriol supplementation. The percentage increase in BMD at 33 months was as high as 94.3% in areas with the lowest BMD at baseline. The BMD at 33 months was higher than the +2SD of the population-specific reference ranges, a finding not reported in surgically treated patients with TIO. An intermittent rise in parathyroid hormone following oral phosphate supplementation might have resulted in such findings.

The effects of abaloparatide on hip geometry and biomechanical properties in Japanese osteoporotic patients assessed using DXA-based hip structural analysis: results of the Japanese phase 3 ACTIVE-J trial

Daily subcutaneous injection of 80 μg abaloparatide increased bone mineral density in Japanese patients with osteoporosis at high fracture risk in the ACTIVE-J trial. Dual-energy X-ray absorptiometry-based hip structural analysis from ACTIVE-J data showed improved hip geometry and biomechanical properties with abaloparatide compared with placebo.

PURPOSE

Abaloparatide (ABL) increased bone mineral density (BMD) in Japanese patients with osteoporosis at high fracture risk in the ACTIVE-J trial. To evaluate the effect of ABL on hip geometry and biomechanical properties, hip structural analysis (HSA) was performed using ACTIVE-J trial data.

METHODS

Hip dual-energy X-ray absorptiometry scans from postmenopausal women and men (ABL, n = 128; placebo, n = 65) at baseline and up to week 78 were analyzed to extract bone geometric parameters at the narrow neck (NN), intertrochanteric region (IT), and proximal femoral shaft (FS). Computed tomography (CT)-based BMD and HSA indices were compared between baseline and week 78.

RESULTS

ABL treatment showed increased mean percent change from baseline to week 78 in cortical thickness at the NN (5.3%), IT (5.3%), and FS (2.9%); cross-sectional area at the NN (5.0%), IT (5.0%), and FS (2.6%); cross-sectional moment of inertia at the NN (7.6%), IT (5.1%), and FS (2.5%); section modulus at the NN (7.4%), IT (5.4%), and FS (2.4%); and decreased mean percent change in buckling ratio (BR) at the IT (- 5.0%). ABL treatment showed increased mean percent change in total volumetric BMD (vBMD; 2.7%) and trabecular vBMD (3.2%) at the total hip and decreased mean percent change in BR at femoral neck (- 4.1%) at week 78 vs baseline. All the changes noted here were significant vs placebo (P < 0.050 using t-test).

CONCLUSION

A 78-week treatment with ABL showed improvement in HSA parameters associated with hip geometry and biomechanical properties vs placebo.

TRIAL REGISTRATION

JAPIC CTI-173575.

Abaloparatide dose-dependently increases bone mineral density in postmenopausal women with osteoporosis: a phase 2 study

INTRODUCTION

This study aimed to determine the efficacy of abaloparatide in increasing bone mineral density (BMD) and its safety in postmenopausal Japanese women with osteoporosis.

MATERIALS AND METHODS

Randomized, double-blind, placebo-controlled, dose-finding study of abaloparatide in postmenopausal Japanese women at high fracture risk. The primary endpoint was the change in lumbar spine (LS) BMD from baseline at the last visit after daily subcutaneous injections of placebo or 40 or 80 µg abaloparatide. Other endpoints included time-course changes in LS BMD at 12, 24, and 48 weeks, in total hip (TH) and femoral neck (FN) BMDs, and in bone turnover markers.

RESULTS

Increases in LS BMD with 40 and 80 µg abaloparatide were significantly higher than that with placebo (6.6% and 11.5%, respectively), with significant between-group differences for the abaloparatide groups (4.9%). TH BMD increased by 0.4%, 1.6%, and 2.9% and FN BMD increased by 0.6%, 1.5%, and 2.4% in the placebo and 40 and 80 µg abaloparatide groups, respectively. Serum PINP rapidly increased by 67.3% and 140.7% and serum CTX slowly increased by 16.4% and 34.5% in the 40 and 80 µg abaloparatide groups, respectively. Although more adverse events were observed in the abaloparatide groups, they were mild to moderate and not dose dependent.

CONCLUSION

In postmenopausal Japanese women with osteoporosis at high fracture risk, abaloparatide for 48 weeks dose-dependently increased LS, TH, and FN BMDs, supporting further investigation with 80 μg abaloparatide for the treatment of osteoporosis in this population.

TRIAL REGISTRATION NUMBER

JapicCTI-132381.

Efficacy of osteoporosis pharmacological treatments in men: a systematic review and meta-analysis

INTRODUCTION

The objective of this systematic review and meta-analysis is to systematically identify and review the efficacy of pharmacological treatments in men with osteoporosis.

METHODS

Medline (via Ovid) and Cochrane CENTRAL were searched up to May 2023 for any randomized controlled trial (RCT) evaluating the efficacy of osteoporotic treatment on the evolution of Bone Mineral Density (BMD) and incidence of fractures of men suffering from primary osteoporosis. If at least two studies used the same pharmacological treatment and evaluated the same outcome, a random effect model meta-analysis was applied to reported pooled mean difference (MD) and 95% confidence interval (CI).

RESULTS

From the 1,061 studies identified through bibliographic search, 21 RCTs fitted the inclusion criteria. Bisphosphonates (k = 10, n = 2992 men with osteoporosis) improved all three BMD sites compared to placebo; lumbar spine: MD + 4.75% (95% CI 3.45, 6.05); total hip: MD + 2.72% (95% CI 2.06; 3.37); femoral neck: MD + 2.26% (95% CI 1.67; 2.85). Denososumab (k = 2, n = 242), Teriparatide (k = 2, n = 309) and Abaloparatide (k = 2, n = 248) also produced significant improvement of all sites BMD compared to placebo. Romosozumab was only identified in one study and was therefore not meta-analysed. In this study, Romosozumab increased significantly BMD compared to placebo. Incident fractures were reported in 16 RCTs but only four reported fractures as the primary outcome. Treatments were associated with a lower incidence of fractures.

CONCLUSIONS

Medications used in the management of osteoporosis in women appear to provide similar benefits in men with osteoporosis. Therefore, the algorithm for the management of osteoporosis in men could be similar to the one previously recommended for the management of osteoporosis in women.

Abnormal changes of bone metabolism markers with age in children with cerebral palsy

Cerebral palsy (CP) is a broad range of diseases with permanent and nonprogressive motor impairments, carrying a high cost for both the individual and the society. The characteristics of low bone mineral density and high risk of fractures suggest that bone metabolism disorders are present in CP. This study aims to investigate the association between indicators of bone metabolism and children with CP. A total of 139 children (75 children with CP and 64 healthy controls) were included in this cross-sectional study. Participants were divided into three age groups (0-2 years, 2.1-4 years, and 4.1-7 years). All children with CP were diagnosed according to clinical criteria and furtherly divided into clinical subtypes. The levels of total procollagen type I N-terminal propeptide (TPINP), N-MID osteocalcin (OC), beta-crosslaps (β-CTX), 25-hydroxyvitamin D (25-OHD) and parathyroid hormone (PTH) in the serum were measured with corresponding detection kits according to the manufacturer's instructions. Serum levels of TPINP and 25-OHD were lower with older age, whereas β-CTX and PTH were higher with older age. In the CP group, TPINP (age 0-2 years and 2.1-4 years) and OC (age 2.1-4 years) levels were higher, while β-CTX (age 2.1-4 years and 4.1-7 years) and PTH (age 2.1-4 years) values were lower than the control group. In addition, there were no statistically significant differences in the levels of these indicators among the CP subgroups with different clinical characteristics. Our study shows that bone turnover markers, indicators of bone metabolism, in children with CP differ significantly from healthy controls. The indicators we studied changed with age, and they did not correlate with disease severity.

Abaloparatide Maintains Normal Rat Blood Calcium Level in Part Via 1,25-Dihydroxyvitamin D/osteocalcin Signaling Pathway

The PTH-related peptide(1-34) analog, abaloparatide (ABL), is the second anabolic drug available for the treatment of osteoporosis. Previous research demonstrated that ABL had a potent anabolic effect but caused hypercalcemia at a significantly lower rate. However, the mechanism by which ABL maintains the stability of blood calcium levels remains poorly understood. Our in vivo data showed that ABL treatment (40 µg/kg/day for 7 days) significantly increased rat blood level of 1,25-dihydroxyvitamin D [1,25-(OH)2D] without raising the blood calcium value. ABL also significantly augmented the carboxylated osteocalcin (Gla-Ocn) in the blood and bone that is synthesized by osteoblasts, and increased noncarboxylated Ocn, which is released from the bone matrix to the circulation because of osteoclast activation. The in vitro data showed that ABL (10 nM for 24 hours) had little direct effects on 1,25-(OH)2D synthesis and Gla-Ocn formation in nonrenal cells (rat osteoblast-like cells). However, ABL significantly promoted both 1,25-(OH)2D and Gla-Ocn formation when 25-hydroxyvitamin D, the substrate of 1α-hydroxylase, was added to the cells. Thus, the increased 1,25-(OH)2D levels in rats treated by ABL result in high levels of Gla-Ocn and transient calcium increase in the circulation. Gla-Ocn then mediates calcium ions in the extracellular fluid at bone sites to bind to hydroxyapatite at bone surfaces. This regulation by Gla-Ocn at least, in part, maintains the stability of blood calcium levels during ABL treatment. We conclude that the signaling pathway of ABL/1,25-(OH)2D/Gla-Ocn contributes to calcium homeostasis and may help understand the mechanism of ABL for osteoporosis therapy.