The Effect of Abaloparatide-SC on Fracture Risk Is Independent of Baseline FRAX Fracture Probability: A Post Hoc Analysis of the ACTIVE Study

Update on fracture risk assessment in osteoporosis

PURPOSE OF REVIEW

The assessment of fracture risk is playing an ever-increasing role in osteoporosis clinical management and informing international guidelines for osteoporosis. FRAX, a fracture risk calculator that provides individualized 10-year probabilities of hip and major osteoporotic fracture, has been widely used since 2008. In this review, we recap the development and limitations of intervention thresholds and the role of absolute fracture risk.

RECENT FINDINGS

There is an increasing awareness of disparities and inequities in the setting of intervention thresholds in osteoporosis. The limitations of the simple use of prior fracture or the DXA-derived BMD T -score threshold are increasingly being discussed; one solution is to use fracture risk or probabilities in the setting of such thresholds. This approach also permits more objective assessment of high and very high fracture risk to enable physicians to make choices not just about the need to treat but what agents to use in individual patients.

SUMMARY

Like all clinical tools, FRAX has limitations that need to be considered, but the use of fracture risk in deciding who to treat, when to treat and what agent to use is a mechanism to target treatment equitably to those at an increased risk of fracture.

An overview of the use of the fracture risk assessment tool (FRAX) in osteoporosis

FRAX®, a simple-to-use fracture risk calculator, was first released in 2008 and since then has been used increasingly worldwide. By calculating the 10-year probabilities of a major osteoporotic fracture and hip fracture, it assists clinicians when deciding whether further investigation, for example a bone mineral density measurement (BMD), and/or treatment is needed to prevent future fractures. In this review, we explore the literature around osteoporosis and how FRAX has changed its management. We present the characteristics of this tool and describe the use of thresholds (diagnostic and therapeutic). We also present arguments as to why screening with FRAX should be considered. FRAX has several limitations which are described in this review. This review coincides with the release of a version, FRAXplus, which addresses some of these limitations.

Effectiveness of romosozumab in patients with osteoporosis at high fracture risk: a Japanese real-world study

INTRODUCTION

To describe the real-world use of romosozumab in Japan, we conducted a chart review of > 1000 Japanese patients with osteoporosis (OP) at high risk of fracture, across multiple medical institutions.

MATERIALS AND METHODS

Treatment-naïve and prior OP-treatment patients who received romosozumab for 12 months followed by ≥ 6 months of sequential OP treatment were included. The primary objective described the baseline demographics and clinical characteristics; secondary objectives evaluated changes in bone mineral density (BMD) and bone turnover markers in all patients and effectiveness of romosozumab in a sub-group of treatment-naïve patients using the fracture risk assessment tool (FRAX®).

RESULTS

Of the 1027 patients (92.4% female), 45.0% were treatment-naïve. The mean ± SD age of treatment-naïve versus prior OP-treatment patients was 76.8 ± 8.5 and 77.1 ± 8.5 years. The most frequent prior OP treatment was bisphosphonates (45.0%). Romosozumab treatment for 12 months increased BMD at the lumbar spine in all groups; the median percent change from baseline in lumbar spine BMD was higher in the treatment-naïve (13.4%) versus prior OP-treatment group (bisphosphonates [9.2%], teriparatide [11.3%], denosumab [DMAb, 4.5%]). DMAb, bisphosphonates, or teriparatide after romosozumab maintained the BMD gains at all skeletal sites at month 18 in treatment-naïve patients. Most treatment-naïve patients were at high risk of fracture, BMD increased consistently with romosozumab regardless of the baseline fracture risk assessed by FRAX.

CONCLUSION

This large-scale, multicenter chart review provides clinically relevant insights into the profiles of patients initiating romosozumab, effectiveness of real-world romosozumab use, and sequential therapy in Japanese patients at high risk of fracture.

Fracture risk reduction and safety by osteoporosis treatment compared with placebo or active comparator in postmenopausal women: systematic review, network meta-analysis, and meta-regression analysis of randomised clinical trials

OBJECTIVE

To review the comparative effectiveness of osteoporosis treatments, including the bone anabolic agents, abaloparatide and romosozumab, on reducing the risk of fractures in postmenopausal women, and to characterise the effect of antiosteoporosis drug treatments on the risk of fractures according to baseline risk factors.

DESIGN

Systematic review, network meta-analysis, and meta-regression analysis of randomised clinical trials.

DATA SOURCES

Medline, Embase, and Cochrane Library to identify randomised controlled trials published between 1 January 1996 and 24 November 2021 that examined the effect of bisphosphonates, denosumab, selective oestrogen receptor modulators, parathyroid hormone receptor agonists, and romosozumab compared with placebo or active comparator.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials that included non-Asian postmenopausal women with no restriction on age, when interventions looked at bone quality in a broad perspective. The primary outcome was clinical fractures. Secondary outcomes were vertebral, non-vertebral, hip, and major osteoporotic fractures, all cause mortality, adverse events, and serious cardiovascular adverse events.

RESULTS

The results were based on 69 trials (>80 000 patients). For clinical fractures, synthesis of the results showed a protective effect of bisphosphonates, parathyroid hormone receptor agonists, and romosozumab compared with placebo. Compared with parathyroid hormone receptor agonists, bisphosphonates were less effective in reducing clinical fractures (odds ratio 1.49, 95% confidence interval 1.12 to 2.00). Compared with parathyroid hormone receptor agonists and romosozumab, denosumab was less effective in reducing clinical fractures (odds ratio 1.85, 1.18 to 2.92 for denosumab v parathyroid hormone receptor agonists and 1.56, 1.02 to 2.39 for denosumab v romosozumab). An effect of all treatments on vertebral fractures compared with placebo was found. In the active treatment comparisons, denosumab, parathyroid hormone receptor agonists, and romosozumab were more effective than oral bisphosphonates in preventing vertebral fractures. The effect of all treatments was unaffected by baseline risk indicators, except for antiresorptive treatments that showed a greater reduction of clinical fractures compared with placebo with increasing mean age (number of studies=17; β=0.98, 95% confidence interval 0.96 to 0.99). No harm outcomes were seen. The certainty in the effect estimates was moderate to low for all individual outcomes, mainly because of limitations in reporting, nominally indicating a serious risk of bias and imprecision.

CONCLUSIONS

The evidence indicated a benefit of a range of treatments for osteoporosis in postmenopausal women for clinical and vertebral fractures. Bone anabolic treatments were more effective than bisphosphonates in the prevention of clinical and vertebral fractures, irrespective of baseline risk indicators. Hence this analysis provided no clinical evidence for restricting the use of anabolic treatment to patients with a very high risk of fractures.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019128391.

Is abaloparatide more efficacious on increasing bone mineral density than teriparatide for women with postmenopausal osteoporosis? An updated meta-analysis

PURPOSE

Osteoporosis poses a challenge to public health, causing fragility fractures, especially in postmenopausal women. Abaloparatide (ABL) is an effective anabolic agent to improve bone formation and resorption among postmenopausal women with osteoporosis. Our meta-analysis aims to assess the effectiveness and safety of ABL versus teriparatide (TPTD) in improving bone mineral density (BMD).

METHODS

We searched Medline, Embase, Web of Science, Cochrane databases and Clinicaltrial.gov until September 2, 2022. We included data from randomized controlled trials (RCTs) and post hoc analyses of RCTs. Outcomes included BMD change from baseline and risks of adverse events. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tool was used to evaluate the quality of outcomes.

RESULTS

Four studies including 16 subgroups were included in this study. In particular, RCTs with head-to-head comparisons of ABL and TPTD were used in the meta-analysis, and all were from manufacturer-sponsored trials. All parameters in 24 weeks except lumbar spine (versus TPTD) showed significant advantages in the ABL group. Only the results of two subgroups in ABL versus TPTD demonstrated High GRADE quality (femoral neck: weighted mean difference (WMD) = 1.58 [0.52, 2.63]; Total hip: WMD = 1.46 [0.59, 2.32]). However, our fracture data were insufficient. Besides, we found no evident difference in serious adverse events or deaths in either group and the incidence of hypercalcemia in the ABL group lessened by 51% compared with the TPTD group. Nevertheless, compared with placebo, ABL demonstrated higher risks of nausea and palpitations.

CONCLUSION

ABL demonstrated a beneficial effect on BMD compared to both placebo and TPTD for postmenopausal women with osteoporosis. ABL also had insignificantly lowered adverse event risk than TPTD. ABL is an alternative for patients with postmenopausal osteoporosis.

Effectiveness and Safety of Treatments to Prevent Fractures in People With Low Bone Mass or Primary Osteoporosis: A Living Systematic Review and Network Meta-analysis for the American College of Physicians

BACKGROUND

The prevalence of osteoporosis is increasing in the United States.

PURPOSE

To evaluate low bone mass and osteoporosis treatments to prevent fractures.

DATA SOURCES

Ovid MEDLINE ALL, Ovid Evidence Based Medicine Reviews: Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and ClinicalTrials.gov from 2014 through February 2022.

STUDY SELECTION

Adults receiving eligible interventions for low bone mass or osteoporosis. Randomized controlled trials (RCTs) for fracture outcomes, and RCTs and large observational studies (n ≥1000) for harms.

DATA EXTRACTION

Abstracted by 1 reviewer and verified by a second. Independent, dual assessments of risk of bias and certainty of evidence (CoE).

DATA SYNTHESIS

We included 34 RCTs (in 100 publications) and 36 observational studies. Bisphosphonates and denosumab reduced hip, clinical and radiographic vertebral, and other clinical fractures in postmenopausal females with osteoporosis (moderate to high CoE). Bisphosphonates for 36 months or more may increase the risk for atypical femoral fractures (AFFs) and osteonecrosis of the jaw (ONJ), but the absolute risks were low. Abaloparatide and teriparatide reduced clinical and radiographic vertebral fractures but increased the risk for withdrawals due to adverse events (WAEs; moderate to high CoE). Raloxifene and bazedoxifene for 36 months or more reduced radiographic vertebral but not clinical fractures (low to moderate CoE). Abaloparatide, teriparatide, and sequential romosozumab, then alendronate, may be more effective than bisphosphonates in reducing clinical fractures for 17 to 24 months in older postmenopausal females at very high fracture risk (low to moderate CoE). Bisphosphonates may reduce clinical fractures in older females with low bone mass (low CoE) and radiographic vertebral fractures in males with osteoporosis (low to moderate CoE).

LIMITATION

Few studies examined participants with low bone mass, males, or Black-identifying persons, sequential therapy, or treatment beyond 3 years.

CONCLUSION

Bisphosphonates, denosumab, abaloparatide, teriparatide, and romosozumab, followed by alendronate, reduce clinical fractures in postmenopausal females with osteoporosis. Abaloparatide and teriparatide increased WAEs; longer duration bisphosphonate use may increase AFF and ONJ risk though these events were rare.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42021236220).

Menopausal hormone therapy reduces the risk of fracture regardless of falls risk or baseline FRAX probability-results from the Women's Health Initiative hormone therapy trials

In a combined analysis of 25,389 postmenopausal women aged 50-79 years, enrolled in the two Women's Health Initiative hormone therapy trials, menopausal hormone therapy vs. placebo reduced the risk of fracture regardless of baseline FRAX fracture probability and falls history.

INTRODUCTION

The aim of this study was to determine if the anti-fracture efficacy of menopausal hormone therapy (MHT) differed by baseline falls history or fracture risk probability as estimated by FRAX, in a combined analysis of the two Women's Health Initiative (WHI) hormone therapy trials.

METHODS

A total of 25,389 postmenopausal women aged 50-79 years were randomized to receive MHT (n = 12,739) or matching placebo (n = 12,650). At baseline, questionnaires were used to collect information on falls history, within the last 12 months, and clinical risk factors. FRAX 10-year probability of major osteoporotic fracture (MOF) was calculated without BMD. Incident clinical fractures were verified using medical records. An extension of Poisson regression was used to investigate the relationship between treatment and fractures in (1) the whole cohort; (2) those with prior falls; and (3) those without prior falls. The effect of baseline FRAX probability on efficacy was investigated in the whole cohort.

RESULTS

Over 4.3 ± 2.1 years (mean ± SD), MHT (vs. placebo) significantly reduced the risk of any clinical fracture (hazard ratio [HR] 0.72 [95% CI, 0.65-0.78]), MOF (HR 0.60 [95% CI, 0.53-0.69]), and hip fracture (0.66 [95% CI, 0.45-0.96]). Treatment was effective in reducing the risk of any clinical fracture, MOF, and hip fracture in women regardless of baseline FRAX MOF probability, with no evidence of an interaction between MHT and FRAX (p > 0.30). Similarly, there was no interaction (p > 0.30) between MHT and prior falls.

CONCLUSION

In the combined WHI trials, compared to placebo, MHT reduces fracture risk regardless of FRAX probability and falls history in postmenopausal women.

Fracture risk assessment by the FRAX model

The introduction of the FRAX algorithms has facilitated the assessment of fracture risk on the basis of fracture probability. FRAX integrates the influence of several well-validated risk factors for fracture with or without the use of bone mineral density. Since age-specific rates of fracture and death differ across the world, FRAX models are calibrated with regard to the epidemiology of hip fracture (preferably from national sources) and mortality (usually United Nations sources). Models are currently available for 73 nations or territories covering more than 80% of the world population. FRAX has been incorporated into more than 80 guidelines worldwide, although the nature of this application has been heterogeneous. The limitations of FRAX have been extensively reviewed. Arithmetic procedures have been proposed in order to address some of these limitations, which can be applied to conventional FRAX estimates to accommodate knowledge of dose exposure to glucocorticoids, concurrent data on lumbar spine bone mineral density, information on trabecular bone score, hip axis length, falls history, type 2 diabetes, immigration status and recency of prior fracture.

Abaloparatide: A review of preclinical and clinical studies

Osteoporosis is a debilitating disease characterized by reduced bone mineral density and an increased risk of fractures. This review aims to provide a comprehensive overview of, and map current knowledge, obtained from preclinical and clinical studies of the osteoanabolic agent abaloparatide. PubMed and Embase were meticulously searched from inception to May 4, 2021.178 titles and abstracts were screened, and 57 full-text articles were assessed for inclusion. A total of 55 articles were included; 5 (9%) in vitro studies, 21 (38%) in vivo studies, and 29 (53%) clinical studies. Preclinical in vitro studies have demonstrated receptor conformation preferability, structural insights into the receptor-agonist complex, and proliferative effects of abaloparatide on osteoblasts. Preclinical studies have shown abaloparatide to be similarly effective to teriparatide using comparable doses in both ambulating mice and rats challenged by disuse. Other animal studies have reported that abaloparatide effectively mitigates or prevents bone loss from ovariectomy, orchiectomy, and glucocorticoids and improves fracture healing. The pivotal clinical study ACTIVE demonstrated 18 months of treatment with abaloparatide substantially increase bone mineral density and reduce fracture risk in post-menopausal women compared with placebo. The extension study ACTIVExtend highlighted that subsequent treatment with alendronate sustained the bone gained by abaloparatide treatment and the reduced fracture risk for up to two years. Post-hoc sub-group analyses have also supported the efficacy and safety of abaloparatide treatment independent of various baseline risk factors. In conclusion, mounting evidence from preclinical and clinical studies has uniformly reported that abaloparatide increases bone mineral density and reduces fracture risk.

Romosozumab efficacy on fracture outcomes is greater in patients at high baseline fracture risk: a post hoc analysis of the first year of the frame study

This study aimed to determine the interaction between baseline FRAX^® fracture probability and romosozumab efficacy. Using an ITT approach, it was determined that the efficacy of romosozumab on clinical fracture, osteoporotic fracture, and major osteoporotic fracture is significantly greater in patients at high baseline fracture risk, when compared with placebo.

INTRODUCTION

Post hoc analyses of placebo-controlled osteoporosis treatment studies have shown significantly greater reductions of fracture incidence for higher fracture risk patients. This study determined the interaction between baseline FRAX^® fracture probability and romosozumab efficacy in the placebo-controlled first year of the phase 3 FRAME study (NCT01575834).

METHODS

Using an ITT approach, an extension of Poisson regression analysis studied the relationship between treatment, FRAX^® 10-year probability of major osteoporotic fracture (MOF, calculated without BMD) and risk of first incident fracture (adjusting for age and follow-up time). Treatment interactions considered outcomes of all clinical fractures, osteoporotic fractures, MOF, clinical vertebral fractures, and morphometric vertebral fractures. Two-sided p value of < 0.1 for the interaction between treatment and FRAX^® was considered significant.

RESULTS

Compared with placebo, romosozumab reduced the incidence of all fracture outcomes in the first year (range: 32% reduction in MOF [p = 0.07] to 80% reduction in clinical vertebral fractures [p = 0.038]). Significant interactions were observed between efficacy and baseline FRAX^® probability for composite outcomes of clinical fractures, osteoporotic fractures, and MOF (p = 0.064-0.084), but not vertebral fractures (p > 0.3). For example, romosozumab decreased all clinical fractures by 22% at the 25th centile of FRAX^® probability but the reduction was 41% at the 75th centile. Exclusion of vertebral fractures from each composite fracture outcome (i.e. only nonvertebral fractures included) showed even stronger interactions with baseline FRAX^® probability (p = 0.036-0.046).

CONCLUSIONS

Efficacy of romosozumab on clinical fracture, osteoporotic fracture, and MOF is significantly greater in patients at high baseline fracture risk compared with placebo.

Anabolic Agents for Postmenopausal Osteoporosis: How Do You Choose?

PURPOSE OF REVIEW

There are now three anabolic agents available for the treatment of postmenopausal women at high risk for fracture. The purpose of this review is to supply a rationale to aid in determining which agent should be used in which clinical settings.

RECENT FINDINGS

Studies over the last decade have shown that anabolic agents produce faster and larger effects against fracture than antiresorptive agents. Furthermore, trials evaluating anabolic antiresorptive treatment sequences have shown that anabolic first treatment strategies produce the greatest benefits to bone density, particularly in the hip region. However, there are no head-to-head evaluations of the three anabolic therapies with fracture outcomes or bone density, and these studies are not likely to occur. How to decide which agent to use at which time in a woman's life is unknown. We review the most significant clinical trials of anabolic agents which have assessed fracture, areal or volumetric bone density, microarchitecture, and/or bone strength, as well as information gleaned from histomorphometry studies to provide a rationale for consideration of one agent vs another in various clinical settings. There is no definitive answer to this question; all three agents increase bone strength and reduce fracture risk rapidly. Since the postmenopausal lifespan could be as long as 40-50 years, it is likely that very high-risk women will utilize different anabolic agents at different points in their lives.

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.

Efficacy of teriparatide compared with risedronate on FRAX®-defined major osteoporotic fractures: results of the VERO clinical trial

FRAX^® calculates the 10-year probability of major osteoporotic fractures (MOF), which are considered to have a greater clinical impact than other fractures. Our results suggest that, in postmenopausal women with severe osteoporosis, those treated with teriparatide had a 60% lower risk of FRAX^®-defined MOF compared with those treated with risedronate.

INTRODUCTION

The VERO trial was an active-controlled fracture endpoint clinical trial that enrolled postmenopausal women with severe osteoporosis. After 24 months, a 52% reduction in the hazard ratio (HR) of clinical fractures was reported in patients randomized to teriparatide compared with risedronate. We examined fracture results restricted to FRAX^®-defined major osteoporotic fractures (MOF), which include clinical vertebral, hip, humerus, and forearm fractures.

METHODS

In total, 1360 postmenopausal women (mean age 72.1 years) were randomized to receive subcutaneous daily teriparatide (20 μg) or oral weekly risedronate (35 mg). Patient cumulative incidence of ≥ 1 FRAX^®-defined MOF and of all clinical fractures were estimated by Kaplan-Meier analyses, and the comparison between treatments was based on the stratified log-rank test. Additionally, an extended Cox model was used to estimate HRs at different time points. Incidence fracture rates were estimated at each 6-month interval.

RESULTS

After 24 months, 16 (2.6%) patients in the teriparatide group had ≥ 1 low trauma FRAX^®-defined MOF compared with 40 patients (6.4%) in the risedronate group (HR 0.40; 95% CI 0.23-0.68; p = 0.001). Clinical vertebral and radius fractures were the most frequent FRAX^®-defined MOF sites. The largest difference in incidence rates of both FRAX^®-defined MOF and all clinical fractures between treatments occurred during the 6- to 12-month period. There was a statistically significant reduction in fractures between groups as early as 7 months for both categories of clinical fractures analyzed.

CONCLUSION

In postmenopausal women with severe osteoporosis, treatment with teriparatide was more efficacious than risedronate, with a 60% lower risk of FRAX^®-defined MOF during the 24-month treatment period. Fracture risk was statistically significantly reduced at 7 months of treatment.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov Identifier: NCT01709110 EudraCT Number: 2012-000123-41.

Identification of osteogenic progenitor cell-targeted peptides that augment bone formation

Activation and migration of endogenous mesenchymal stromal cells (MSCs) are critical for bone regeneration. Here, we report a combinational peptide screening strategy for rapid discovery of ligands that not only bind strongly to osteogenic progenitor cells (OPCs) but also stimulate osteogenic cell Akt signaling in those OPCs. Two lead compounds are discovered, YLL3 and YLL8, both of which increase osteoprogenitor osteogenic differentiation in vitro. When given to normal or osteopenic mice, the compounds increase mineral apposition rate, bone formation, bone mass, and bone strength, as well as expedite fracture repair through stimulated endogenous osteogenesis. When covalently conjugated to alendronate, YLLs acquire an additional function resulting in a “tri-functional” compound that: (i) binds to OPCs, (ii) targets bone, and (iii) induces “pro-survival” signal. These bone-targeted, osteogenic peptides are well suited for current tissue-specific therapeutic paradigms to augment the endogenous osteogenic cells for bone regeneration and the treatment of bone loss.

Activation of osteogenic cells is essential for bone regeneration. Here, the authors screen a peptide library and identify 2 compounds that promote osteogenic progenitor cell differentiation in vitro, and show that they increase bone formation and fracture repair in mice.

Practical guidance for the use of bisphosphonates in osteoporosis

Bisphosphonates are widely used in the treatment of osteoporosis in postmenopausal women and older men. In clinical trials they have been shown to reduce fractures in women with osteoporosis and there is increasing evidence that they are also effective in women with osteopenia, in whom the majority of fractures occur. In addition to their role as initial therapy in individuals at increased risk of fracture, bisphosphonates are used as sequential therapy after treatment with anabolic drugs. There are no head-to head studies to compare the anti-fracture efficacy of different bisphosphonates, but there is limited evidence that zoledronate treatment results in greater increases in BMD than risedronate or alendronate. This, together with the need for less frequent administration of zoledronate, supports its wider use in clinical practice, particularly if longer dosing intervals than those currently recommended are shown to be effective.

Osteoporosis treatment considerations based upon fracture history, fracture risk assessment, vertebral fracture assessment, and bone density in Canada

Among 39,475 women, age 65 years and older, use of fracture history, major osteoporotic fracture (MOF) probability from FRAX®, vertebral fracture assessment (VFA), and bone mineral density (BMD) T-score stratified women into different levels of risk. The majority of women identified as being at high risk from fracture history, FRAX MOF-BMD > 20%, or vertebral fracture on VFA had a BMD T-score in the osteoporotic range.

PURPOSE

To inform criteria for pharmacologic treatment in women age 65 years and older, we examined subgroups defined from fracture history, MOF calculated with BMD (MOF-BMD), VFA, and BMD T-score using the population-based Manitoba BMD Program registry.

METHODS

The study population consisted of women age > 65 years was divided into mutually exclusive subgroups based upon fracture history, MOF-BMD ≥ 20%, vertebral fracture on VFA, and osteoporotic BMD T-score. Healthcare records were assessed for the presence of fracture diagnosis codes occurring after DXA assessment. For each subgroup, we estimated the proportion of individuals with BMD T-score in the osteoporotic range, predicted versus observed 10-year MOF probability, hazard ratio (HR) for MOF, and number needed to treat (NNT) for 3 years to prevent a fracture event.

RESULTS

The study population consisted of 39,475 women (median age 72 years). The majority of women (76.8%) selected as being at high risk based on fracture history, MOF-BMD > 20%, or vertebral fracture on VFA had a BMD T-score in the osteoporotic range. During a median follow-up of 8 years, 5169 (13.1%) sustained one or more incident MOF. Fracture rates and HRs generally paralleled the FRAX prediction, except in women with a positive VFA where predicted risk based upon clinical risk factors prior to VFA underestimated the observed risk. NNT differed by the risk subgroup, and showed a gradient of decreasing NNT (consistent with greater benefit) in individuals with the highest fracture risk.

CONCLUSIONS

Fracture history, fracture probability from FRAX, targeted vertebral fracture assessment (VFA), and BMD T-score can stratify older women into different levels of risk and treatment benefit. These results are expected to inform clinical practice guidelines in Canada.

Comparison of treatment strategies and thresholds for optimizing fracture prevention in Canada: a simulation analysis

This comparison of osteoporosis treatment strategies and intervention thresholds highlights tradeoffs in terms of number of individuals qualifying for treatment and estimated fractures prevented.

PURPOSE

The current analysis was performed to inform the following key question as part of the Osteoporosis Canada's Osteoporosis Guidelines Update: "What is the best strategy to identify those at high fracture risk for pharmacotherapy in order to prevent the most fractures, considering both population and patient perspectives?"

METHODS

The study population consisted of 66,878 women age 50 years and older (mean age 66.0 ± 9.7 years) with documented fracture probability assessment (FRAX) and fracture outcomes. Fractures over the next 5 years were identified through linked administrative healthcare data. We estimated the fraction of the population that would warrant treatment and the number of fractures avoided per 1000 person-years according to multiple strategies and thresholds. Strategies were then rank ordered using 19 metrics.

RESULTS

During mean 4.4 years, 863 (3.5%) sustained one or more major osteoporotic fractures (MOF), 212 (0.8%) sustained a hip fracture, and 1210 (4.9%) sustained any incident fracture. For woman age 50-64 years, the highest ranked strategy was treatment based upon total hip T score ≤ -2.5, but several other strategies fell within 0.5 overall ranking. For women age 65 years and older, MOF > 20% was the highest ranked strategy with no closely ranked strategies. Pooling both age subgroups gave MOF > 20% as the highest ranked strategy, with several other strategies within 0.5 overall ranking.

CONCLUSIONS

Choice of treatment strategy and threshold for osteoporosis management strongly influences the number of individuals for whom pharmacologic treatment would be recommended and on estimated fracture rates in the population. This evidence-based approach to comparing these strategies will help to inform guidelines development in Canada and may be on interest elsewhere.

Fracture and Bone Mineral Density Response by Baseline Risk in Patients Treated With Abaloparatide Followed by Alendronate: Results From the Phase 3 ACTIVExtend Trial

In the randomized, placebo-controlled, double-blind phase 3 ACTIVE study (NCT01343004), 18 months of abaloparatide 80 μg daily (subcutaneous injection) in postmenopausal women at risk of osteoporotic fracture significantly reduced the risk of vertebral, nonvertebral, clinical, and major osteoporotic fractures and significantly increased bone mineral density (BMD) versus placebo regardless of baseline risk factors. Women from the abaloparatide and placebo groups who completed ACTIVE were eligible for ACTIVExtend (NCT01657162), in which all enrollees received sequential, open-label monotherapy with alendronate 70 mg once weekly for up to 24 months. This prespecified analysis evaluated whether fracture risk reductions and bone mineral density (BMD) gains associated with abaloparatide during ACTIVE persisted through the full 43-month ACTIVE-ACTIVExtend study period in nine prespecified baseline risk subgroups. Baseline risk subgroups included BMD T-score at the lumbar spine, total hip, and femoral neck (≤ - 2.5 versus > - 2.5 and ≤ -3.0 versus > - 3.0), history of nonvertebral fracture (yes/no), prevalent vertebral fracture (yes/no), and age (<65 versus 65 to <75 versus ≥75 years). Forest plots display treatment effect. Treatment-by-subgroup interactions were tested using the Breslow-Day test, Cox proportional hazards model, and ANCOVA model. After the combined ACTIVE-ACTIVExtend study period, reductions in relative risk for new vertebral, nonvertebral, clinical, and major osteoporotic fractures were greater among patients in the abaloparatide/alendronate group than among those in the placebo/alendronate group across all nine baseline risk subgroups. BMD gains at the lumbar spine, total hip, and femoral neck were greater in the abaloparatide/alendronate group versus the placebo/alendronate group. No clinically meaningful interaction between treatment assignment and any baseline risk variable was observed. The sequence of abaloparatide for 18 months followed by alendronate for up to 24 months appears to be an effective treatment option for a wide range of postmenopausal women at risk for osteoporotic fractures. © 2019 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc.

Anabolics in the management of glucocorticoid-induced osteoporosis: an evidence-based review of long-term safety, efficacy and place in therapy

Introduction

Glucocorticoid-induced osteoporosis is an underrecognized complication of chronic glucocorticoid therapy characterized by a decrease in new bone formation. Anabolic therapies, such as teriparatide, a recombinant human parathyroid hormone, combat the disease by promoting new bone growth.

Aims

This article outlines the pathophysiology of glucocorticoid-induced osteoporosis and details the evidence of efficacy, safety, and patterns of use of teriparatide and other future anabolic therapies.

Evidence review

In multiple clinical trials, teriparatide has been shown to significantly increase lumbar spine bone mineral density (BMD) in patients with glucocorticoid-induced osteoporosis when compared with placebo, alendronate, and risedronate. When compared with alendronate, significantly fewer vertebral fractures were noted in the teriparatide group. Adverse effects noted in clinical trials include nausea, insomnia, flushing, myalgias, and mild hypercalcemia/hyperuricemia. Early studies in rats noted an increased incidence of osteosarcoma; however, an increased rate beyond levels seen in general populations has not been noted in human studies or with long-term pharmacovigilance. Abaloparatide and romosozumab are newer anabolic therapies that have shown some benefit in postmenopausal osteoporosis but have not yet been studied in the chronic glucocorticoid population.

Place in therapy

Major specialty organizations continue to recommend bisphosphonates as first-line therapy in glucocorticoid-induced osteoporosis due to the proven benefit and relative affordability. However, the use of anabolics shows promise to improve outcomes by increasing BMD and reducing fracture-associated morbidity and mortality and has a role for selected populations at high fracture risk.

Anti-fracture efficacy of zoledronate in subgroups of osteopenic postmenopausal women: secondary analysis of a randomized controlled trial

BACKGROUND

We recently reported that the administration of zoledronate every 18 months to osteopenic older women reduces the incidence of fractures.

OBJECTIVE

Here, we present a more detailed analysis of that trial to determine whether baseline clinical characteristics impact on the anti-fracture efficacy of this intervention.

METHODS

This is a prospective, randomized, placebo-controlled, double-blind trial in osteopenic postmenopausal women aged ≥ 65 years, to determine the anti-fracture efficacy of zoledronate. 2000 women were recruited using electoral rolls and randomized to receive 4 infusions of either zoledronate 5 mg or normal saline, at 18-month intervals. Each participant was followed for 6 years. Calcium supplements were not supplied.

RESULTS

Fragility fractures (either vertebral or nonvertebral) occurred in 190 women in the placebo group (227 fractures) and in 122 women in the zoledronate group (131 fractures), odds ratio (OR) 0.59 (95%CI 0.46, 0.76; P < 0.0001). There were no significant interactions between baseline variables (age, anthropometry, BMI, dietary calcium intake, baseline fracture status, recent falls history, bone mineral density, calculated fracture risk) and the treatment effect. In particular, the reduction in fractures appeared to be independent of baseline fracture risk, and numbers needed to treat (NNT) to prevent one woman fracturing were not significantly different across baseline fracture risk tertiles.

CONCLUSIONS

The present analyses indicate that the decrease in fracture numbers is broadly consistent across this cohort. The lack of relationship between NNTs and baseline fracture risk calls into question the need for BMD measurement and precise fracture risk assessment before initiating treatment in older postmenopausal women.

Osteoanabolic and dual action drugs

Teriparatide (TPTD) and abaloparatide (ABL) are the only osteoanabolic drugs available, at this time, for treatment of osteoporosis. TPTD is a 34-amino acid fragment that is identical in its primary sequence to the 34 amino acids of full-length human parathyroid hormone [hPTH(1-84)]. ABL is identical to parathyroid hormone-related peptide (PTHrP) through the first 22 residues with significantly different amino acids inserted thereafter, between residues 22 and 34. The osteoanabolic actions of PTH are due directly to its effects on cells of the osteoblast lineage and indirectly by stimulating IGF-I synthesis and suppressing sclerostin and associated enhancement of Wnt signalling. Both TPTD and ABL are ligands that bind to and activate the PTH receptor type 1 (PTHR1) receptor but they appear to do so differently: ABL favours the transient, more anabolic configuration of the receptor. Both TPTD and ABL reduce the risk of vertebral fractures and non-vertebral fractures. Both drugs are administered for a maximum of 24 months, and should be followed by an antiresorptive agent to maintain gains in bone mineral density (BMD). Romosozumab, a monoclonal antibody that binds to and inhibits sclerostin, appears to have dual actions by stimulating bone formation and reducing bone resorption. In the pivotal clinical trial, romosozumab, administered as a 210 mg monthly subcutaneous dose, significantly reduced new vertebral fractures and in a subsequent study reduced both vertebral and non-vertebral fractures.

Cost-effectiveness Analysis of Sequential Treatment of Abaloparatide Followed by Alendronate Versus Teriparatide Followed by Alendronate in Postmenopausal Women With Osteoporosis in the United States

BACKGROUND

The US Food and Drug Administration has recently approved abaloparatide (ABL) for treatment of women with postmenopausal osteoporosis (PMO) at high risk of fracture. With increasing health care spending and drug prices, it is important to quantify the value of newly available treatment options for PMO.

OBJECTIVE

To determine cost-effectiveness of ABL compared with teriparatide (TPTD) for treatment of women with PMO in the United States.

METHODS

A discrete-event simulation (DES) model was developed to assess cost-effectiveness of ABL from the US health care perspective. The model included three 18-month treatment strategies with either placebo (PBO), TPTD, or ABL, all followed by additional 5-year treatment with alendronate (ALN). High-risk patients were defined as women with PMO ⩾65 years old with a prior vertebral fracture. Baseline clinical event rates, risk reductions, and patient characteristics were based on the Abaloparatide Comparator Trial in Vertebral Endpoints (ACTIVE) trial.

RESULTS

Over a 10-year period, the DES model yielded average total discounted per-patient costs of $10 212, $46 783, and $26 837 and quality-adjusted life-years (QALYs) of 6.742, 6.781, and 6.792 for PBO/ALN, TPTD/ALN, and ABL/ALN, respectively. Compared with TPTD/ALN, ABL/ALN accrued higher QALYs at lower cost and produced an incremental cost-effectiveness ratio (ICER) of $333 266/QALY relative to PBO/ALN. In high-risk women, ABL/ALN also had more QALYs and less cost over TPTD/ALN and yielded an ICER of $188 891/QALY relative to PBO/ALN. Conclusion and Relevance: ABL is a dominant treatment strategy over TPTD. In women with PMO at high risk of fracture, ABL is an alternative cost-effective treatment.

Novel therapies in osteoporosis: PTH-related peptide analogs and inhibitors of sclerostin

Bone-forming approaches to treat patients with severe osteoporosis are effective, but treatment options are limited, and there is an unmet clinical need for additional drugs. This review discusses two novel and advanced anabolic therapeutic concepts that have successfully completed phase 3 trials. Romosozumab is a monoclonal antibody that targets the Wnt inhibitor sclerostin. Two phase 3 trials (FRAME and ARCH) of romosozumab for the treatment of postmenopausal osteoporosis have been completed. Both trials successfully reached their primary endpoint by reducing vertebral fractures by 75% compared to placebo (FRAME trial) and 48% compared to alendronate (ARCH trial), respectively. Abaloparatide is a PTH-related protein (PTHrP) analog that has displayed bone anabolic activity. In the phase 3 ACTIVE trial, abaloparatide was compared to placebo and teriparatide for 18 months in postmenopausal women who had already experienced an osteoporotic fracture. Abaloparatide successfully reduced the rate of new vertebral fractures by 86% compared to placebo. Furthermore, abaloparatide achieved greater BMD increases at all measured sites compared to both placebo and teriparatide. Based on these results, abaloparatide was FDA approved in April 2017. This review discusses available data of both agents with regard to efficacy and safety as well as their possible future application.

Effect of abaloparatide on vertebral, nonvertebral, major osteoporotic, and clinical fractures in a subset of postmenopausal women at increased risk of fracture by FRAX probability

We evaluated the efficacy of abaloparatide in women who were at increased risk for fracture, based on CHMP recommended risk thresholds, at the Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) study baseline. Among patients at high risk based on FRAX probabilities, 18 months of abaloparatide significantly decreased risk for all fracture endpoints compared with placebo.

PURPOSE

Abaloparatide, a novel anabolic agent for the treatment of postmenopausal osteoporosis, significantly reduced the risk of vertebral and nonvertebral fractures in the ACTIVE study compared with placebo. In this post hoc analysis, we evaluated abaloparatide's efficacy in a subset of women in the study at an increased risk of fracture at baseline, based on the Committee for Medicinal Products for Human Use (CHMP) recommended risk thresholds for inclusion in clinical trials.

METHODS

Women with a baseline 10-year risk of major osteoporotic fracture ≥ 10% or hip fracture ≥ 5%, assessed using the FRAX® tool (including femoral neck bone mineral density), were included in the analysis. The proportion with one or more events of new morphometric vertebral fractures was calculated. Event rates for nonvertebral, major osteoporotic, and all clinical fractures were estimated using Kaplan-Meier analysis.

RESULTS

Following 18 months of treatment, abaloparatide significantly reduced incident vertebral fractures compared with placebo (relative risk reduction = 91%; 0.5% versus 5.6%; p < 0.001). Abaloparatide treatment was also associated with significantly fewer nonvertebral, major osteoporotic, and clinical fractures compared with placebo: 2.7% versus 5.8%, p = 0.036; 1.3% versus 6.0%, p < 0.001; and 3.5% versus 8.2%, p = 0.006, respectively. The effect of abaloparatide on major osteoporotic fractures (78% reduction) was significantly greater than that seen with teriparatide (23% reduction, p = 0.007).

CONCLUSION

In a subset of postmenopausal women at increased risk of fracture as judged by CHMP guidance, abaloparatide significantly decreased the risk of all fracture endpoints compared with placebo.

Risk of subsequent fracture after prior fracture among older women

Among 377,561 female Medicare beneficiaries who sustained a fracture, 10% had another fracture within 1 year, 18% within 2 years, and 31% within 5 years. Timely management to reduce risk of subsequent fracture is warranted following all nontraumatic fractures, including nonhip nonvertebral fractures, in older women.

INTRODUCTION

Prior fracture is a strong predictor of subsequent fracture; however, postfracture treatment rates are low. Quantifying imminent (12-24 month) risk of subsequent fracture in older women may clarify the need for early postfracture management.

METHODS

This retrospective cohort study used Medicare administrative claims data. Women ≥ 65 years who sustained a clinical fracture (clinical vertebral and nonvertebral fracture; index date) and were continuously enrolled for 1-year pre-index and ≥ 1-year (≥  2 or ≥ 5 years for outcomes at those time points) post-index were included. Cumulative incidence of subsequent fracture was calculated from 30 days post-index to 1, 2, and 5 years post-index. For appendicular fractures, only those requiring hospitalization or surgical repair were counted. Death was considered a competing risk.

RESULTS

Among 377,561 women (210,621 and 10,969 for 2- and 5-year outcomes), cumulative risk of subsequent fracture was 10%, 18%, and 31% at 1, 2, and 5 years post-index, respectively. Among women age 65-74 years with initial clinical vertebral, hip, pelvis, femur, or clavicle fractures and all women ≥ 75 years regardless of initial fracture site (except ankle and tibia/fibula), 7-14% fractured again within 1 year depending on initial fracture site; risk rose to 15-26% within 2 years and 28-42% within 5 years. Risk of subsequent hip fracture exceeded 3% within 5 years in all women studied, except those < 75 years with an initial tibia/fibula or ankle fracture.

CONCLUSIONS

We observed a high and early risk of subsequent fracture following a broad array of initial fractures. Timely management with consideration of pharmacotherapy is warranted in older women following all fracture types evaluated.

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.

A brief history of FRAX

This paper reviews the research programme that went into the development of FRAX® and its impact in the 10 years since its release in 2008.

INTRODUCTION

Osteoporosis is defined on the measurement of bone mineral density though the clinical consequence is fracture. The sensitivity of bone mineral density measurements for fracture prediction is low, leading to the development of FRAX to better calculate the likelihood of fracture and target anti-osteoporosis treatments.

METHODS

The method used in this paper is literature review.

RESULTS

FRAX, developed over an 8-year period, was launched in 2008. Since the launch of FRAX, models have been made available for 64 countries and in 31 languages covering more than 80% of the world population.

CONCLUSION

FRAX provides an advance in fracture risk assessment and a reference technology platform for future improvements in performance characteristics.

Review of the guideline of the American College of Physicians on the treatment of osteoporosis

This review, endorsed by the International Osteoporosis Foundation and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, summarizes several failings of the recent guidelines of the American College of Physicians (ACP) on the treatment of low bone density or osteoporosis to prevent fractures.

INTRODUCTION

The ACP recently issued guidelines for the treatment of low bone density or osteoporosis to prevent fractures.

METHODS

Literature review and critical review of the ACP guidelines.

RESULTS

The guideline is lacking in scope due to the endorsement of treatment based on T-scores rather than fracture risk assessment and in failure to adequately consider anabolic therapies.

CONCLUSIONS

The ACP guideline appears outdated.

Management of Patients With High Baseline Hip Fracture Risk by FRAX Reduces Hip Fractures-A Post Hoc Analysis of the SCOOP Study

The Screening for Osteoporosis in Older Women for the Prevention of Fracture (SCOOP) study was a community-based screening intervention in women aged 70 to 85 years in the United Kingdom. In the screening arm, licensed osteoporosis treatments were recommended in women identified to be at high risk of hip fracture using the FRAX risk assessment tool (including bone mineral density measurement). In the control arm, standard care was provided. Screening led to a 28% reduction in hip fractures over 5 years. In this planned post hoc analysis, we wished to examine for interactions between screening effectiveness on fracture outcome (any, osteoporotic, and hip fractures) on the one hand and baseline FRAX 10-year probability of hip fracture on the other. All analyses were conducted on an intention-to-treat basis, based on the group to which women were randomized, irrespective of whether screening was completed. Of 12,483 eligible participants, 6233 women were randomized to screening, with treatment recommended in 898 (14.4%). No evidence of an effect or interaction was observed for the outcomes of any fracture or osteoporotic fracture. In the screening arm, 54 fewer hip fractures were observed than in the control arm (164 versus 218, 2.6% versus 3.5%), and commensurate with treatment being targeted to those at highest hip fracture risk, the effect on hip fracture increased with baseline FRAX hip fracture probability (p = 0.021 for interaction); for example, at the 10th percentile of baseline FRAX hip probability (2.6%), there was no evidence that hip fractures were reduced (hazard ratio [HR] = 0.93; 95% confidence interval [CI] 0.71 to 1.23), but at the 90th percentile (16.6%), there was a 33% reduction (HR = 0.67; 95% CI 0.53 to 0.84). Prior fracture and parental history of hip fracture positively influenced screening effectiveness on hip fracture risk. We conclude that women at high risk of hip fracture based on FRAX probability are responsive to appropriate osteoporosis management. © 2018 American Society for Bone and Mineral Research.

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.

FRAX-based intervention and assessment thresholds in seven Latin American countries

Age-specific intervention and assessment thresholds were developed for seven Latin American countries. The intervention threshold ranged from 1.2% (Ecuador) to 27.5% (Argentina) at the age of 50 and 90 years, respectively. In the Latin American countries, FRAX offers a substantial advance for the detection of subjects at high fracture risk.

INTRODUCTION

Intervention thresholds are proposed using the Fracture Risk Assessment (FRAX) tool. We recommended their use to calculate the ten-year probability of fragility fracture (FF) in both, men and women with or without the inclusion of bone mineral density (BMD). The purpose of this study is to compute FRAX-based intervention and BMD assessment thresholds for seven Latin American countries in men and women ≥ 40 years.

METHODS

The intervention threshold (IT) was set at a 10-year probability of a major osteoporotic fracture (MOF) equivalent to a woman with a prior FF and a body mass index (BMI) equal to 25.0 kg/m² without BMD or other clinical risk factors. The lower assessment threshold was set at a 10-year probability of a MOF in women with BMI equal to 25.0 kg/m², no previous fracture and no clinical risk factors. The upper assessment threshold was set at 1.2 times the IT.

RESULTS

For the seven LA countries, the age-specific IT varied from 1.5 to 27.5% in Argentina, 3.8 to 25.2% in Brazil, 1.6 up to 20.0% in Chile, 0.6 to 10.2% in Colombia, 0.9 up to 13.6% in Ecuador, 2.6 to 20.0% in Mexico, and 0.7 up to 22.0% in Venezuela at the age of 40 and 90 years, respectively.

CONCLUSIONS

In the LA countries, FRAX-based IT offers a substantial advance for the detection of men and women at high fracture risk, particularly in the elderly. The heterogeneity of IT between the LA countries indicates that country-specific FRAX models are appropriate rather than a global LA model.

MANAGEMENT OF ENDOCRINE DISEASE: Novel anabolic treatments for osteoporosis

Skeletal anabolic agents enhance bone formation, which is determined by the number and function of osteoblasts. Signals that influence the differentiation and function of cells of the osteoblast lineage play a role in the mechanism of action of anabolic agents in the skeleton. Wnts induce the differentiation of mesenchymal stem cells toward osteoblasts, and insulin-like growth factor I (IGF-I) enhances the function of mature osteoblasts. The activity of Wnt and IGF-I is controlled by proteins that bind to the growth factor or to its receptors. Sclerostin is a Wnt antagonist that binds to Wnt co-receptors and prevents Wnt signal activation. Teriparatide, a 1-34 amino terminal fragment of parathyroid hormone (PTH), and abaloparatide, a modified 1-34 amino terminal fragment of PTH-related peptide (PTHrp), induce IGF-I, increase bone mineral density (BMD), reduce the incidence of vertebral and non-vertebral fractures and are approved for the treatment of postmenopausal osteoporosis. Romosozumab, a humanized anti-sclerostin antibody, increases bone formation, decreases bone resorption, increases BMD and reduces the incidence of vertebral fractures. An increased incidence of cardiovascular events has been associated with romosozumab, which is yet to be approved for the treatment of osteoporosis. In conclusion, cell and molecular studies have formed the foundation for the development of new anabolic therapies for osteoporosis with proven efficacy on the incidence of new fractures.

Abaloparatide: Review of a Next-Generation Parathyroid Hormone Agonist

OBJECTIVE

To review the efficacy, safety, and economics of abaloparatide in the treatment of postmenopausal osteoporosis.

DATA SOURCES

PubMed (1966 to October 2017), Clinicaltrials.gov (October 2017), and Scopus (1970 to October 2017) were searched using abaloparatide, Tymlos, BA058, PTHrP 1-34 analog, and parathyroid hormone-related peptide 1-34 analog.

STUDY SELECTION AND DATA EXTRACTION

Human studies published in peer-reviewed publications in English were the primary sources for efficacy, safety, and economic data.

DATA SYNTHESIS

In the 2 randomized, published clinical studies of 24 weeks and 18 months duration, bone mineral density changes were higher for abaloparatide (lumbar spine, 6.7%-11.2%; femoral head, 3.1%-3.2%; total hip, 2.6%-4.2%) compared with placebo (lumbar spine, 0.6%-1.6%; femoral head, -0.4% to 0.8%; total hip, -0.1% to 0.4%; P < 0.05) and compared with teriparatide in the 24-week study (total hip 2.6% vs +0.5%, P < 0.05). New vertebral and nonvertebral fractures occurred in 0.6% and 2.7% of patients on abaloparatide compared with 4.2% and 4.7% on placebo in the 18-month study ( P < 0.05). Abaloparatide appears to have a somewhat higher risk for adverse effects, discontinuation as a result of adverse effects, and serious or severe adverse effects than teriparatide, but teriparatide has a higher risk for hypercalcemia. Pharmacoeconomic modeling appears to favor abaloparatide if differences in efficacy and cost are maintained.

CONCLUSION

Abaloparatide, which has less effect on osteoclasts, is an alternative to teriparatide in patients with postmenopausal osteoporosis who are at high risk for fractures or who have failed antiresorptive therapy based on initial clinical studies and economic modeling.