Abaloparatide is an Effective Treatment Option for Postmenopausal Osteoporosis: Review of the Number Needed to Treat Compared with Teriparatide.

Abaloparatide (ABL) is a 34-amino acid peptide designed to be a selective activator of the parathyroid hormone receptor type 1 signaling pathway. In the Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE), subcutaneous ABL reduced the risk of new vertebral, nonvertebral, clinical, and major osteoporotic fracture compared with placebo and of major osteoporotic fracture compared with teriparatide. To further evaluate the effectiveness of ABL, we calculated the number needed to treat (NNT) to prevent one fracture using ACTIVE data. To estimate the potential effectiveness of ABL in populations at higher fracture risk than in ACTIVE, we calculated NNT for vertebral fracture using reference populations from historical placebo-controlled trials, assuming an 86% relative risk reduction in vertebral fracture with ABL treatment as observed in ACTIVE. NNT was calculated as the reciprocal of the absolute risk reduction in ACTIVE. The projected NNT for ABL in other populations was calculated based on incidence rate (IR) for vertebral fractures in the placebo arms of the FREEDOM (placebo IR 7.2%), FIT-1 (placebo IR 15.0%), and FIT-2 (placebo IR 3.8%) trials. NNT for ABL in ACTIVE was 28 for vertebral, 55 for nonvertebral, 37 for clinical, and 34 for major osteoporotic fracture. NNT for these fracture types for teriparatide in ACTIVE were 30, 92, 59, and 75, respectively. Using placebo IRs from FREEDOM, FIT-1, and FIT-2, projected NNTs for vertebral fracture with ABL were 17, 8, and 31. These data are useful for further evaluating ABL for the treatment of osteoporosis in postmenopausal women.

Correction to: Geography of Fracture Incidence in Postmenopausal Women with Osteoporosis Treated with Abaloparatide.

The article Geography of Fracture Incidence in Postmenopausal Women with Osteoporosis Treated with Abaloparatide, written by Michael R. McClung, Gregory C. Williams, Gary Hattersley, Lorraine A. Fitzpatrick, Yamei Wang, Paul D. Miller, was originally published electronically on the publisher's internet portal (currently SpringerLink) on 28 December 2017 without open access.

Geography of Fracture Incidence in Postmenopausal Women with Osteoporosis Treated with Abaloparatide.

Geographic heterogeneity has been observed in fracture risk and efficacy of therapeutic intervention in postmenopausal osteoporosis. The objectives of these analyses were to assess across geographic and ethnic subgroups the heterogeneity of fracture incidence and baseline risk, and consistency of effect of abaloparatide-SC vs placebo on fracture risk reduction in the 18-month, phase 3, multinational, ACTIVE randomized controlled trial. Prespecified exploratory analyses of geographic subgroups (North America, South America, Europe, Asia) and post hoc analyses of ethnic subgroups (Hispanic or Latino, other) of postmenopausal women with osteoporosis enrolled in the abaloparatide-SC and placebo cohorts (n = 1645) were performed. Country-specific FRAX models were used to calculate 10-year absolute fracture risks. Relative risk reductions for vertebral fractures and hazard ratios for non-vertebral, clinical, and major osteoporotic fractures were calculated. Forest plots were constructed to assess treatment-by-subgroup interactions for each geographic region and ethnicity. Baseline prevalence of vertebral fractures was similar across geographies; baseline prevalence of non-vertebral fractures was more variable. Ten-year major osteoporosis fracture and hip fracture risks were variable across and within regions. The effects of abaloparatide-SC on reducing the risk of vertebral, non-vertebral, clinical, and major osteoporotic fractures were similar across regions, and for Hispanic or Latino vs other ethnicities. A limitation was the limited power to detect interactions with few events. In conclusion, despite geographic variability in fracture incidence and risk at baseline, no differences were detected in the effects of abaloparatide-SC in reducing vertebral, non-vertebral, clinical, and major osteoporotic fracture risk across assessed geographic regions and ethnicities.

A Challenging Case of Tumor-Induced Osteomalacia: Pathophysiological and Clinical Implications.

We investigated the usefulness of fibroblast growth factor 23 (FGF23) intraoperative assay to monitor tumor resection in patients with oncogenic osteomalacia. A 33-year-old man with 5 years' history of lumbar and pelvis pain together with multiple vertebral fractures was admitted to our hospital. He was diagnosed with ankylosing spondylitis 1 year before. Laboratory investigation showed low tubular reabsorption of phosphate (0.41 mmol/L) despite chronic hypophosphatemia (0.39/L). Increased plasma values of FGF23 (673 pg/mL; n.v. < 95 pg/mL) were also observed. A full-body CT scan showed two suspicious areas in the head of the right femur and in the right tibia; however, the Octreoscan™ showed an increased uptake of the tracer only in the femur. We decided to remove first the head femur lesion and perform intraoperative FGF23 assay to confirm tumor resection; if this had been unsuccessful, we would have extended the operation to excise the second bone lesion. FGF23 basal values and 10, 60, and 225 min after excision of the femoral head were 423, 127, 56, and 30 pg/mL, respectively. The brisk fall of FGF23 values suggested that the head femur lesion was responsible for the syndrome. Histological examination revealed a mesenchymal highly vascular tumor. This is the first report showing the possibility of intraoperative FGF23 assay to monitor tumor resection in patients with tumor-induced osteomalacia.

Evaluation of Quantitative Computed Tomography Cortical Hip Quadrant in a Clinical Trial With Rosiglitazone: A Potential New Study Endpoint.

Quantitative computed tomography (QCT) measurements have been used extensively to ascertain information about bone quality and density due to the 3-dimensional information provided and the ability to segment out trabecular and cortical bones. QCT imaging helps to improve our understanding of the role that each bone compartment plays in the pathogenesis and prognosis of fracture. This study was conducted to explore longitudinal changes in femoral neck (FN) cortical bone structure using both volumetric bone mineral density (vBMD) and cortical shell thickness assessments via QCT in a double-blind, randomized, multicenter clinical trial in postmenopausal women with type 2 diabetes mellitus. This study also examined whether treatment-associated changes in the cortical bone vBMD and thickness in femoral neck quadrants could be evaluated. Subjects were randomized to rosiglitazone (RSG) or metformin (MET) for 52 wk followed by 24 wk of open-label MET. A subset of 87 subjects underwent QCT scans of the hip at baseline, after 52 wk of double-blind treatment, and after 24 wk of treatment with MET using standard full-body computed tomography scanners. All scans were evaluated and analyzed centrally. Cortical vBMD at the FN was precisely segmented from trabecular bone and used to assess a possible therapeutic effect on this bone compartment. QCT analysis showed reductions in adjusted mean percentage change in vBMD and in absolute cortical thickness occurred with RSG treatment from baseline to week 52, whereas changes with MET were generally minimal. The reductions observed during RSG treatment for 1 yr appeared to partially reverse during the open-label MET phase from weeks 52 to 76. The femoral neck quadrant may provide utility as a potential endpoint in clinical trials for the understanding of the therapeutic effect of new entities on cortical bone vs trabecular bone; however, further clinical validation is needed. TRIAL REGISTRATION: The protocol (GSK study number AVD111179) was registered on ClinicalTrials.gov as NCT00679939.

Effect of Abaloparatide vs Placebo on New Vertebral Fractures in Postmenopausal Women With Osteoporosis: A Randomized Clinical Trial.

IMPORTANCE: Additional therapies are needed for prevention of osteoporotic fractures. Abaloparatide is a selective activator of the parathyroid hormone type 1 receptor. OBJECTIVE: To determine the efficacy and safety of abaloparatide, 80 µg, vs placebo for prevention of new vertebral fracture in postmenopausal women at risk of osteoporotic fracture. DESIGN, SETTING, AND PARTICIPANTS: The Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) was a phase 3, double-blind, RCT (March 2011-October 2014) at 28 sites in 10 countries. Postmenopausal women with bone mineral density (BMD) T score ≤-2.5 and >-5.0 at the lumbar spine or femoral neck and radiological evidence ≥2 mild or ≥1 moderate lumbar or thoracic vertebral fracture or history of low-trauma nonvertebral fracture within the past 5 years were eligible. Postmenopausal women (>65 y) with fracture criteria and a T score ≤-2.0 and >-5.0 or without fracture criteria and a T score ≤-3.0 and >-5.0 could enroll. INTERVENTIONS: Blinded, daily subcutaneous injections of placebo (n = 821); abaloparatide, 80 µg (n = 824); or open-label teriparatide, 20 µg (n = 818) for 18 months. MAIN OUTCOMES AND MEASURES: Primary end point was percentage of participants with new vertebral fracture in the abaloparatide vs placebo groups. Sample size was set to detect a 4% difference (57% risk reduction) between treatment groups. Secondary end points included change in BMD at total hip, femoral neck, and lumbar spine in abaloparatide-treated vs placebo participants and time to first incident nonvertebral fracture. Hypercalcemia was a prespecified safety end point in abaloparatide-treated vs teriparatide participants. RESULTS: Among 2463 women (mean age, 69 years [range, 49-86]), 1901 completed the study. New morphometric vertebral fractures occurred less frequently in the active treatment groups vs placebo. The Kaplan-Meier estimated event rate for nonvertebral fracture was lower with abaloparatide vs placebo. BMD increases were greater with abaloparatide than placebo (all P < .001). Incidence of hypercalcemia was lower with abaloparatide (3.4%) vs teriparatide (6.4%) (risk difference [RD], −2.96 [95%CI, −5.12 to −0.87]; P = .006). [table: see text]. CONCLUSIONS AND RELEVANCE: Among postmenopausal women with osteoporosis, the use of subcutaneous abaloparatide, compared with placebo, reduced the risk of new vertebral and nonvertebral fractures over 18 months. Further research is needed to understand the clinical importance of RD, the risks and benefits of abaloparatide treatment, and the efficacy of abaloparatide vs other osteoporosis treatments. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01343004.

Erratum for Abaloparatide in Postmenopausal Women With Osteoporosis and Type 2 Diabetes: A Post Hoc Analysis of the ACTIVE Study.

[This corrects the article DOI: 10.1002/jbm4.10346.].

Cost-effectiveness of sequential treatment with abaloparatide followed by alendronate vs. alendronate monotherapy in women at increased risk of fracture: A US payer perspective.

OBJECTIVES: Emerging evidence supports sequential therapy with anabolic followed by antiresorptive in patients at high-risk of fragility fractures. This study assessed the cost-effectiveness of sequential treatment with abaloparatide (ABL) followed by alendronate (ALN) [(ABL/ALN)] compared to ALN monotherapy and to sequential treatment starting with antiresorptive therapy (ALN/ABL/ALN). METHODS: A previously validated Markov microsimulation model was used to estimate the cost-effectiveness of sequential ABL/ALN compared to ALN monotherapy and to sequential ALN/ABL/ALN from a lifetime US payer perspective. In line with practice guidelines, patients were assumed to receive ABL for 18 months followed by 5 years of ALN, or ALN monotherapy for 5 years, or a sequence of ALN for 2 years followed by 18 months of ABL and then by 3 years ALN. Evaluation was conducted for patients aged 50-80 years old with a BMD T-score ≤-3.5 and without a history of prior fracture, or with a T-score between -2.5 and -3.5 and a history of ≥ 1 osteoporotic fracture. RESULTS: Sequential ABL/ALN was cost-effective (threshold of US$150,000 per QALY) vs generic ALN monotherapy in women ≥60 years with a BMD T-score ≤-3.5 and in women with BMD T-score between -2.5 and -3.5 and history of osteoporotic fracture. In all simulated populations, sequential ABL/ALN therapy was dominant (lower costs, more QALYs) compared with sequential ALN/ABL/ALN, resulting from limited effect of ABL in patients previously treated with an antiresorptive agent. CONCLUSIONS: Sequential ABL/ALN therapy is cost-effective vs ALN monotherapy for US postmenopausal women aged ≥60 years at increased risk of fractures.

Abaloparatide: an anabolic treatment to reduce fracture risk in postmenopausal women with osteoporosis.

OBJECTIVE: Fractures due to osteoporosis represent a serious burden on patients and healthcare systems. The objective of this review is to provide an overview of the anabolic agent abaloparatide (ABL) for the treatment of postmenopausal women with osteoporosis at high risk for fracture. METHODS: A literature review was conducted using PubMed to identify articles focused on ABL published prior to February 10, 2020, using the search term "abaloparatide". RESULTS: ABL, a synthetic analog of human parathyroid hormone-related protein, increased bone mineral density (BMD), improved bone microarchitecture, and increased bone strength in preclinical and clinical studies. The pivotal phase 3 trial ACTIVE and its extension (ACTIVExtend) demonstrated the efficacy of initial treatment with ABL for 18 months followed by sequential treatment with alendronate (ALN) for an additional 24 months to reduce the risk of vertebral, nonvertebral, clinical, and major osteoporotic fractures and to increase BMD in postmenopausal women with osteoporosis. Discontinuations from ACTIVE were slightly more common in ABL-treated patients due to dizziness, palpitations, nausea, and headache. Post hoc analyses of ACTIVE and ACTIVExtend support the efficacy and safety of ABL in relevant subpopulations including postmenopausal women with various baseline risk factors, women ≥80 years, women with type 2 diabetes mellitus, and women with renal impairment. CONCLUSIONS: ABL is an effective and well-tolerated treatment for women with postmenopausal osteoporosis at high risk for fracture. Its therapeutic effects are sustained with subsequent ALN therapy.

Abaloparatide followed by alendronate in women ≥80 years with osteoporosis: post hoc analysis of ACTIVExtend.

OBJECTIVE: Fracture risk increases with age, but few studies focus on persons ≥80 years. In the ACTIVE trial, treatment with abaloparatide for 18 months reduced osteoporotic fracture risk and increased bone mineral density. These effects were maintained with 24 months alendronate treatment in ACTIVExtend. We postulated that similar improvements in bone mineral density and safety would be demonstrated in women ≥80 years. METHODS: Post hoc analyses of bone mineral density and fracture incidence in women with osteoporosis at high risk of fracture ≥80 years from ACTIVExtend. RESULTS: In total, 56 women aged ≥80 years at ACTIVE baseline entered the ACTIVExtend study; 46 of these completed the study. Mean age was 83.3 years; other baseline characteristics were similar. At the end of ACTIVE, bone mineral density increased at all sites for abaloparatide versus placebo. Bone mineral density increased in parallel in both groups during alendronate therapy (19 to 43 months) in ACTIVExtend. At month 43, mean percent change in bone mineral density from baseline was 17.2% abaloparatide/alendronate versus 8.6% placebo/alendronate (P < 0.0001) at the lumbar spine, 5.3% abaloparatide/alendronate versus 3.0% placebo/alendronate (P = 0.024) at the total hip, and 4.6% abaloparatide/alendronate versus 3.1% placebo/alendronate (P = 0.044) at the femoral neck. Fracture incidence was low and did not differ significantly between groups. Sequential treatment with abaloparatide followed by alendronate was well tolerated; the proportion of participants reporting adverse events was similar between groups. CONCLUSIONS: Sequential treatment with abaloparatide followed by alendronate (43 months follow-up) in this small subgroup of ACTIVExtend participants suggests abaloparatide is well tolerated and effective in women aged ≥80 years. : Video Summary:http://links.lww.com/MENO/A618.

Video Summary:http://links.lww.com/MENO/A618.

Abaloparatide in Postmenopausal Women With Osteoporosis and Type 2 Diabetes: A Post Hoc Analysis of the ACTIVE Study.

Type 2 diabetes mellitus (T2DM) increases fracture risk despite normal or increased BMD. Abaloparatide reduces fracture risk in patients with postmenopausal osteoporosis (PMO); however, its efficacy in women with T2DM is unknown. This post hoc analysis evaluated the efficacy and safety of abaloparatide in patients with T2DM. The analysis included patients with T2DM from the Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE), a phase 3, double-blind, randomized, placebo- and active-controlled trial. In ACTIVE, participants were randomized 1:1:1 to daily s.c. injections of placebo, abaloparatide (80 µg), or open-label teriparatide (20 µg) for 18 months. A total of 198 women with PMO and T2DM from 21 centers in 10 countries were identified from ACTIVE through review of their medical records. The main outcomes measured included effect of abaloparatide versus placebo on BMD and trabecular bone score (TBS), with secondary outcomes of fracture risk and safety, in patients from ACTIVE with T2DM. Significant (p < 0.001) improvements in BMD at total hip (mean change 3.0% versus -0.4%), femoral neck (2.6% versus -0.2%), and lumbar spine (8.9% versus 1.3%) and TBS at lumbar spine (3.72% versus -0.56%) were observed with abaloparatide versus placebo at 18 months. Fracture events were fewer with abaloparatide treatment in patients with T2DM, and differences were not significant between groups except nonvertebral fractures in the abaloparatide versus placebo groups (p = 0.04). Safety was consistent with the ACTIVE population. In conclusion, in women with PMO and T2DM, abaloparatide treatment resulted in significant improvements in BMD and TBS versus placebo, consistent with the overall ACTIVE population © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Once-monthly oral ibandronate improves biomechanical determinants of bone strength in women with postmenopausal osteoporosis.

CONTEXT: Bone strength and fracture resistance are determined by bone mineral density (BMD) and structural, mechanical, and geometric properties of bone. DESIGN, SETTING, AND OBJECTIVES: This randomized, double-blind, placebo-controlled outpatient study evaluated effects of once-monthly oral ibandronate on hip and lumbar spine BMD and calculated strength using quantitative computed tomography (QCT) with finite element analysis (FEA) and dual-energy x-ray absorptiometry (DXA) with hip structural analysis (HSA). PARTICIPANTS: Participants were women aged 55-80 yr with BMD T-scores -2.0 or less to -5.0 or greater (n = 93). INTERVENTION: Oral ibandronate 150 mg/month (n = 47) or placebo (n = 46) was administered for 12 months. OUTCOME MEASURES: The primary end point was total hip QCT BMD change from baseline; secondary end points included other QCT BMD sites, FEA, DXA, areal BMD, and HSA. All analyses were exploratory, with post hoc P values. RESULTS: Ibandronate increased integral total hip QCT BMD and DXA areal BMD more than placebo at 12 months (treatment differences: 2.2%, P = 0.005; 2.0%, P = 0.003). FEA-derived hip strength to density ratio and femoral, peripheral, and trabecular strength increased with ibandronate vs. placebo (treatment differences: 4.1%, P < 0.001; 5.9%, P < 0.001; 2.5%, P = 0.011; 3.5%, P = 0.003, respectively). Ibandronate improved vertebral, peripheral, and trabecular strength and anteroposterior bending stiffness vs. placebo [7.1% (P < 0.001), 7.8% (P < 0.001), 5.6% (P = 0.023), and 6.3% (P < 0.001), respectively]. HSA-estimated femoral narrow neck cross-sectional area and moment of inertia and outer diameter increased with ibandronate vs. placebo (respectively 3.6%, P = 0.003; 4.0%, P = 0.052; 2.2%, P = 0.049). CONCLUSIONS: Once-monthly oral Ibandronate for 12 months improved hip and spine BMD measured by QCT and DXA and strength estimated by FEA of QCT scans.

Response rates for hip, femoral neck, and lumbar spine bone mineral density in patients treated with abaloparatide followed by alendronate: Results from phase 3 ACTIVExtend.

Abaloparatide is a selective activator of the parathyroid hormone type 1 receptor signaling pathway that favors the stimulation of bone formation. Here, we report a prospective, exploratory analysis of bone mineral density (BMD) response rates comparing sequential abaloparatide/alendronate vs placebo/alendronate across the ACTIVE and ACTIVExtend studies. BMD was measured at the lumbar spine, total hip, and femoral neck from the beginning of ACTIVE to the end of ACTIVExtend (18 months of abaloparatide or placebo followed by about 1 month for re-consent, followed by 24 months of alendronate treatment for a total of 43 months). Responders were defined as those patients who had improvements in BMD at 3 anatomic sites-the lumbar spine, total hip, and femoral neck. Three response thresholds, >0%, >3%, and >6%, were evaluated. Five hundred fifty-eight patients in the abaloparatide/alendronate group and 581 patients in the placebo/alendronate group from ACTIVExtend were included in the analysis. At Month 43, a significantly greater proportion of those in the abaloparatide/alendronate group compared with the placebo/alendronate group responded with BMD changes from ACTIVE baseline of >0%, >3%, and >6% at all 3 anatomic sites (p < 0.001 for each comparison). At the>3% threshold, 60.7% (307/506) vs 24.0% (121/505) of patients experienced BMD increases at all 3 sites in the abaloparatide/alendronate vs placebo/alendronate groups, respectively (p < 0.001). A significantly greater proportion of the abaloparatide/alendronate group experienced BMD increases of>0%, >3%, and >6% at each individual anatomic site compared with the placebo/alendronate group at 43 months (p < 0.001). Additionally, at each visit in ACTIVExtend, there was a significantly greater proportion of patients in the abaloparatide/alendronate group above the 3% threshold at each anatomic site compared with the placebo/alendronate group. Results are consistent with the significant BMD response with abaloparatide vs placebo observed in ACTIVE and with the continued fracture risk reduction with sequential abaloparatide/alendronate compared with placebo/alendronate treatment observed in ACTIVE through ACTIVExtend.

Cost-effectiveness of sequential treatment with abaloparatide vs. teriparatide for United States women at increased risk of fracture.

OBJECTIVES: There is emerging evidence supporting sequential therapy with an osteoanabolic followed by an antiresorptive in patients at high-risk of fragility fractures. This study assessed the cost-effectiveness of sequential treatment with abaloparatide (ABL) followed by alendronate (ALN) [(ABL/ALN)] compared with teriparatide (TPTD) followed by ALN (TPTD/ALN). METHODS: A previously validated Markov microsimulation model was adapted to estimate the cost-effectiveness of sequential ABL/ALN compared with sequential TPTD/ALN and no treatment with a lifetime horizon from the US payer perspective. Patients were assumed to receive ABL or TPTD for 18 months followed by 5 years of ALN in line with clinical recommendations. The effects of ABL on fracture risk were derived from the ACTIVExtend trial. The effects of TPTD were assumed to be maintained during subsequent ALN treatment, consistent with ACTIVExtend findings for ABL. Evaluation was completed for patients, aged 50-80 years with a BMD T-score ≤ -3.5 or with a T-score between -2.5 and -3.5 and a history of ≥ one osteoporotic fracture. RESULTS: In all simulated populations, sequential ABL/ALN therapy was dominant (lower costs, higher QALYs) compared with sequential TPTD/ALN therapy, resulting from the improved efficacy and lower drug price of ABL. Probabilistic sensitivity analyses suggested that ABL/ALN was dominant in at least 99% of the simulations. Compared to no treatment, the cost per QALY gained of ABL/ALN was always below $130,000. CONCLUSIONS: Sequential ABL/ALN therapy is a cost-effective (dominant) strategy compared with sequential TPTD/ALN therapy for the treatment of US women at increased risk of fractures.

Abaloparatide in patients with mild or moderate renal impairment: results from the ACTIVE phase 3 trial.

Objective: To evaluate, post hoc, the efficacy and safety of abaloparatide by degree of renal impairment.Methods: ACTIVE was a phase 3, 18-month, randomized, double-blind, active-comparator, placebo-controlled study of postmenopausal women with osteoporosis who received subcutaneous abaloparatide 80 µg, placebo, or open-label teriparatide 20 µg daily. Patients with serum creatinine >2.0 mg/dL or 1.5-2.0 mg/dL with an estimated glomerular filtration rate (eGFR) <37 mL/min, calculated by Cockcroft-Gault formula, were excluded.Results: At baseline, 660 patients had eGFR ≥90 mL/min, 1276 had 60 to ˂90 mL/min, and 527 had <60 mL/min. Older age and lower T-scores were associated with greater renal impairment. Among renal-function subgroups, there were no meaningful changes in bone mineral density, fracture risk reduction, or overall incidence of treatment-emergent adverse events in the active-treatment arms. Anemia, nausea, hypercalcemia, and upper-respiratory-tract infection tended to be more frequent with increasing renal impairment. Hypercalcemia measured by albumin-adjusted serum calcium occurred significantly less frequently with abaloparatide than teriparatide in patients with eGFR <60 mL/min (3.6% versus 10.9%; p = .008) and in the overall ACTIVE safety population (3.4% versus 6.4%; p = .006). Computed tomography scans in 376 patients revealed no evidence of increased renal calcification.Conclusion: Increased exposure to abaloparatide and teriparatide in patients with renal impairment led to no meaningful differences in efficacy or safety. These results support the use of abaloparatide without dosage adjustment in patients with renal impairment, provided those with severe renal impairments are monitored for adverse events.

Molecular, endocrine, and genetic mechanisms of arterial calcification.

Pathologists have recognized arterial calcification for over a century. Recent years have witnessed a strong resurgence of interest in atherosclerotic plaque calcification because it: 1) can be easily detected noninvasively; 2) closely correlates with the amount of atherosclerotic plaque; 3) serves as a surrogate measure for atherosclerosis, allowing preclinical detection of the disease; and 4) is associated with heightened risk of adverse cardiovascular events. There are two major types of calcification in arteries: calcification of the media tunica layer (sometimes called Mönckeberg's sclerosis), and calcification within subdomains of atherosclerotic plaque within the intimal layer of the artery. There are important similarities and differences between these two entities. Of particular interest are increasing parallels between cellular and molecular features of arterial calcification and bone biology, and this has led to accelerating interest in understanding how and why bone-like mineral deposits may form in arteries. Here, we review the two major pathological types of arterial calcification, the proposed models of calcification, and endocrine and genetic determinants that affect arterial calcification. In addition, we highlight areas requiring further investigation.

Soy isoflavones: hope or hype?

Approximately 50% of Americans use dietary supplements on a regular basis spending an estimated $20 billion on supplements in the year 2000. Soy contains genistein and daidzein, two phytoestrogens, which work through the estrogen receptor and cause alterations in serum lipids, bone metabolism, and possibly cognition. In this article, we review the issues regarding the interpretation with studies using soy-based isoflavones, discuss their mechanism of action, and review the literature on the effect of these bio-active compounds on lipid metabolism, osteoblasts and osteoclasts, bone markers, bone mineral density, and cognition.

Parathyroid hormone and the cardiovascular system.

The classical actions of parathyroid hormone (PTH) are well recognized, but its effects on other target tissues, such as the cardiovascular system, are less appreciated. Several studies have evaluated the effects of PTH in patients with primary hyperparathyroidism in order to understand potential cardiovascular effects in terms of hypertension, cardiovascular mortality, left ventricular function, and endothelial function. We review these studies and evaluate the cellular mechanisms that may affect these outcomes.

Effects of abaloparatide on bone mineral density and risk of fracture in postmenopausal women aged 80 years or older with osteoporosis.

OBJECTIVE: Advanced age is an important risk factor for fracture. The Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) trial showed that subcutaneous abaloparatide increased bone mineral density (BMD) and reduced the risk of vertebral and nonvertebral fractures in postmenopausal women with osteoporosis. This study describes the effects of abaloparatide in the subgroup of women aged 80 or more years in ACTIVE. METHODS: Post hoc analyses of BMD and fracture incidence in this subgroup of women who received abaloparatide or placebo in the 18-month, phase 3, double-blind, randomized controlled ACTIVE trial. RESULTS: The mean ages of the women ≥80 years were 81.9 and 81.7 years in the placebo (n = 43) and abaloparatide (n = 51) groups, respectively. The increases in BMD from baseline to 18 months with abaloparatide treatment were 3.9% at the total hip (P < 0.001), 3.6% at the femoral neck (P < 0.01), and 12.1% at the lumbar spine (P < 0.001), and were similar to those observed in the overall population. Abaloparatide therapy was associated with numerical, but not statistically significant, reductions in the risk of vertebral and nonvertebral fractures in this subpopulation, compared with placebo. The proportion of participants reporting adverse events was similar between treatment groups and between the older subgroup and the overall population. CONCLUSION: Abaloparatide was effective in increasing BMD in the very elderly subgroup of ACTIVE, with a safety profile similar to that of the overall study population.

ACTIVExtend: 24 Months of Alendronate After 18 Months of Abaloparatide or Placebo for Postmenopausal Osteoporosis.

Purpose: In women with postmenopausal osteoporosis, we investigated the effects of 24 months of treatment with alendronate (ALN) following 18 months of treatment with abaloparatide (ABL) or placebo (PBO). Methods: Women who completed ABL or PBO treatment in ACTIVE were eligible to receive up to 24 months of ALN. We evaluated the incidence of vertebral and nonvertebral fractures and changes in bone mineral density (BMD) during the entire 43-month period from ACTIVE baseline to the end of ACTIVExtend and for the 24-month extension only. Results: Five hundred fifty-eight women from ACTIVE's ABL group and 581 from its PBO group (92% of ABL and PBO completers) were enrolled. During the full 43-month treatment period, 0.9% of evaluable women in the ABL/ALN group experienced a new radiographic vertebral fracture vs 5.6% of women in the PBO/ALN group, an 84% relative risk reduction (RRR, P < 0.001). Kaplan-Meier incidence rates for other reported fracture types were significantly lower for ABL/ALN vs PBO/ALN (all P < 0.05). Gains in BMD achieved during ACTIVE were further increased during ACTIVExtend. For ACTIVExtend only, RRR for vertebral fractures was 87% with ABL/ALN vs PBO/ALN (P = 0.001). Adverse events were similar between groups. A supplemental analysis for regulatory authorities found no hip fractures in the ABL/ALN group vs five in the PBO/ALN group. Conclusions: Eighteen months of ABL followed by 24 months of ALN reduced the risk of vertebral, nonvertebral, clinical, and major osteoporotic fractures and increased BMD. Sequential ABL followed by ALN appears to be an effective treatment option for postmenopausal women at risk for osteoporosis-related fractures.