Effects of increasing age, dosage, and duration of PTH treatment on BMD increase--a meta-analysis

A retrospective analysis of nonresponse to denosumab after hip fractures

Denosumab is an effective antiresorptive drug commonly prescribed for the treatment of osteoporosis. However, some patients do not respond well to denosumab treatment. The aim of this study was to evaluate the factors underlying treatment nonresponses to denosumab in elderly patients following hip fracture. This retrospective study included 130 patients treated with denosumab after osteoporotic hip fracture between March 2017 and March 2020. The patients were categorized as denosumab nonresponders if they had a T-score <-3 that persisted between dual-energy X-ray absorptiometry scans, a >3% decrease in bone mineral density (BMD), or an incident fracture on denosumab therapy. We examined the baseline characteristics associated with blunted BMD responses and compared the groups following denosumab treatment for 12 months. Of 130 patients with baseline data, 105 patients (80.8%) were considered responders. No difference in baseline vitamin D, calcium, BMI, age, gender, prior fracture history, or bisphosphonate use was observed between responders and nonresponders. A longer interval between denosumab injections was associated with suboptimal BMD response at both spine and total hip (p<0.001 and p=0.04, respectively). The overall L-BMD and H-BMD were significantly increased compared with pretreatment levels after denosumab treatment (5.7% and 2.5%, respectively). This study revealed that nonresponse was not strongly associated with certain baseline variables and it appears that the reponders and nonresponders were reasonably comparable in this study population. The results of our study highlight the importance of timely denosumab administration when using this drug for osteoporosis management. Physicians should keep these results in mind in clinical practice so that they can improve utilization of 6-month denosumab.

Factors associated with bone response to teriparatide in young postmenopausal women with osteoporosis

INTRODUCTION

To investigate the factors associated with changes in vertebral bone mineral density during teriparatide treatment.

MATERIALS AND METHODS

Single centre, longitudinal study involving 145 osteoporotic postmenopausal women treated with teriparatide. Clinical evaluation, bone mineral density (BMD) measurements assessment and laboratory analyses were performed at baseline then after 12 and 18 months of treatment. Bone non-response to treatment was defined as no significant increase in BMD at 18 months as compared to baseline.

RESULTS

Of the 145 women initially included, 109 completed the 18-month course of the treatment. 75% of them had a history of prior osteoporotic treatment. Baseline mean age was 60 ± 8 years. Mean baseline vertebral T-score was - 3.7 ± 0.7 and 83 (76%) women had suffered at least one vertebral fracture. At the end of treatment, 18 women (17%) were classified as non-responders. In the responder group (n = 91), vertebral BMD increased by 0.091 ± 0.04 g/cm² (12.2 ± 5.3%). Clinical characteristics, baseline BMDs and the percentage of women previously treated with bisphosphonates as well as the duration of prior treatment did not significantly differ between the two groups of responders and non-responders. At baseline, non-responders had significant mean lower C-terminal fragment of type 1 collagen (CTX) values than responders (p < 0.01). Only baseline CTX values (r = 0.30 p < 0.01) were independently correlated to vertebral BMD changes during teriparatide treatment.

CONCLUSION

A minority of treated women had no vertebral densitometric gain after 18 months of teriparatide therapy. Low levels of baseline bone remodeling were the main factor associated with poor response to treatment.

Dose-dependent effects of pharmaceutical treatments on bone matrix properties in ovariectomized rats

As both anabolic and anti-catabolic osteoporosis drugs affect bone formation and resorption processes, they may contribute to bone's overall mechanical behavior by altering the quality of the bone matrix. We used an ovariectomized rat model and a novel fracture mechanics approach to investigate whether treatment with an anabolic (parathyroid hormone) or anti-catabolic (alendronate) osteoporosis drugs will alter the organic and mineral matrix components and consequently cortical bone fracture toughness. Ovariectomized (at 5 months age) rats were treated with either parathyroid hormone or alendronate at low and high doses for 6 months (age 6–12 months). Specifically, treatment groups included untreated ovariectomized controls (n = 9), high-dose alendronate (n = 10), low-dose alendronate (n = 9), high-dose parathyroid hormone (n = 10), and low-dose parathyroid hormone (n = 9). After euthanasia, cortical microbeams from the lateral quadrant were extracted, notched, and tested in 3-point bending to measure fracture toughness. Portions of the bone were used to measure changes in the 1) organic matrix through quantification of advanced glycation end-products (AGEs) and non-collagenous proteins, and 2) mineral matrix through assessment of mineral crystallinity. Compared to the ovariectomized group, rats treated with high doses of parathyroid hormone and alendronate had significantly increased cortical bone fracture toughness, which corresponded primarily to increased non-collagenous proteins while there was no change in AGEs. Additionally, low-dose PTH treatment increased matrix crystallinity and decreased AGE levels. In summary, ovariectomized rats treated with pharmaceutical drugs had increased non-collagenous matrix proteins and improved fracture toughness compared to controls. Further investigation is required for different doses and longer treatment periods.

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Alendronate increases non-collagenous proteins and improves fracture toughness.

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Parathyroid hormone also increases collagen maturity and mineral crystallinity.

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Both treatments minimize accumulation of advanced glycation end-products.

Denosumab, raloxifene, romosozumab and teriparatide to prevent osteoporotic fragility fractures: a systematic review and economic evaluation

BACKGROUND

Fragility fractures are fractures that result from mechanical forces that would not ordinarily result in fracture.

OBJECTIVES

The objectives were to evaluate the clinical effectiveness, safety and cost-effectiveness of non-bisphosphonates {denosumab [Prolia^®; Amgen Inc., Thousand Oaks, CA, USA], raloxifene [Evista^®; Daiichi Sankyo Company, Ltd, Tokyo, Japan], romosozumab [Evenity^®; Union Chimique Belge (UCB) S.A. (Brussels, Belgium) and Amgen Inc.] and teriparatide [Forsteo^®; Eli Lilly and Company, Indianapolis, IN, USA]}, compared with each other, bisphosphonates or no treatment, for the prevention of fragility fracture.

DATA SOURCES

For the clinical effectiveness review, nine electronic databases (including MEDLINE, EMBASE and the World Health Organization International Clinical Trials Registry Platform) were searched up to July 2018.

REVIEW METHODS

A systematic review and network meta-analysis of fracture and femoral neck bone mineral density were conducted. A review of published economic analyses was undertaken and a model previously used to evaluate bisphosphonates was adapted. Discrete event simulation was used to estimate lifetime costs and quality-adjusted life-years for a simulated cohort of patients with heterogeneous characteristics. This was done for each non-bisphosphonate treatment, a strategy of no treatment, and the five bisphosphonate treatments previously evaluated. The model was populated with effectiveness evidence from the systematic review and network meta-analysis. All other parameters were estimated from published sources. An NHS and Personal Social Services perspective was taken, and costs and benefits were discounted at 3.5% per annum. Fracture risk was estimated from patient characteristics using the QFracture^® (QFracture-2012 open source revision 38, Clinrisk Ltd, Leeds, UK) and FRAX^® (web version 3.9, University of Sheffield, Sheffield, UK) tools. The relationship between fracture risk and incremental net monetary benefit was estimated using non-parametric regression. A probabilistic sensitivity analysis and scenario analyses were used to assess uncertainty.

RESULTS

Fifty-two randomised controlled trials of non-bisphosphonates were included in the clinical effectiveness systematic review and an additional 51 randomised controlled trials of bisphosphonates were included in the network meta-analysis. All treatments had beneficial effects compared with placebo for vertebral, non-vertebral and hip fractures, with hazard ratios varying from 0.23 to 0.94, depending on treatment and fracture type. The effects on vertebral fractures and the percentage change in bone mineral density were statistically significant for all treatments. The rate of serious adverse events varied across trials (0-33%), with most between-group differences not being statistically significant for comparisons with placebo/no active treatment, non-bisphosphonates or bisphosphonates. The incremental cost-effectiveness ratios were > £20,000 per quality-adjusted life-year for all non-bisphosphonate interventions compared with no treatment across the range of QFracture and FRAX scores expected in the population eligible for fracture risk assessment. The incremental cost-effectiveness ratio for denosumab may fall below £30,000 per quality-adjusted life-year at very high levels of risk or for high-risk patients with specific characteristics. Raloxifene was dominated by no treatment (resulted in fewer quality-adjusted life-years) in most risk categories.

LIMITATIONS

The incremental cost-effectiveness ratios are uncertain for very high-risk patients.

CONCLUSIONS

Non-bisphosphonates are effective in preventing fragility fractures, but the incremental cost-effectiveness ratios are generally greater than the commonly applied threshold of £20,000-30,000 per quality-adjusted life-year.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018107651.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 29. See the NIHR Journals Library website for further project information.

Loading modality and age influence teriparatide-induced bone formation in the human femoral neck

Teriparatide (TPTD) reduces risk of both vertebral and nonvertebral fracture, but increases bone mineral density (BMD) much more at the spine than the hip. TPTD and mechanical loading may have a synergistic anabolic effect on BMD, which may help explain these site-specific differences. Under normal daily activity, the femoral neck (FN) is under bending, placing one side under tension and the other under compression. We sought to further understand the relationship between mechanical loading and TPTD at the hip by investigating the effect of tensile versus compressive loading on TPTD stimulated bone formation indices in the human FN. Thirty-eight patients receiving total hip replacements for osteoarthritis were randomized to receive placebo (PBO) or TPTD for a mean treatment duration of 6 weeks prior to surgery, and double tetracycline labeling was administered to allow assessment of bone formation. The FN was harvested during surgery and analyzed for dynamic bone formation indices in the compressive and tensile regions of the endocortical and periosteal envelopes. Regression models relating outcome measures to patient characteristics including sex, age, body weight, and FN geometry were also analyzed. Overall, bone formation was higher with TPTD versus placebo on the endocortical surface, but not the periosteal surface. The level of bone formation in both TPTD and placebo groups was greater on the tensile endocortical surface and the compressive periosteal surface. There was a trend toward decreased endocortical eroded surface with TPTD in the compressive but not the tensile region. Patient age and sex explained the greatest variability in endocortical bone formation, and patient body mass and sex explained the greatest variability in periosteal bone formation. Our data represent the first dynamic comparison of teriparatide treatment under two loading modalities in human FN samples. Future work could determine whether specific hip loading intervention could amplify the benefits of teriparatide on the hip in clinical settings.

The Effect of Parathyroid Hormone Analogues When Added to Mineralized Bone Xenografts

Implants can be a treatment option when there is sufficient quantity and quality of bone to provide support for long-term success. In the reconstruction of defects, autogenous bone remains the gold standard for its osteogenic and compatibility properties. However, the disadvantage of secondary surgery and the associated donor site morbidity prompts researchers to develop the ideal bone substitute for optimum bone reconstruction. Parathyroid hormone (PTH1-34) has provided a new option for improvement in bone regeneration. This study used a pig model to evaluate the effectiveness of parathyroid hormone when added to a xenograft, Bio-Oss, in reconstructing mandible defects. Six domestic pigs were used to create 3 posterior mandibular defects measuring 2 × 1-cm bilaterally with a total of 36 defects to simulate tooth extraction sites in humans. The defects were grafted in random order and divided into 3 groups as follows: control (no graft), Bio-Oss without PTH, and Bio-Oss with PTH. Defects were assessed with cone beam computerized tomography (CBCT), micro computerized tomography (microCT), nanoindentation, and histology. Results showed that adding PTH1-34 significantly enhanced the graft construct. CBCT showed a significant increase in the degree of bone mineralization. Nanoindentation showed increased hardness of regenerated bone and accelerated bone mineralization with PTH. MicroCT analysis revealed a trend toward higher bone regeneration and mineralization. The histological analysis showed a positive trend of the increase in cortical bone thickness and mineral apposition rate. In conclusion, the local addition of PTH1-34 to a xenograft has shown promising results to enhance bone regeneration in the reconstruction of mandibular defects.

Clinical Application of Teriparatide in Fracture Prevention: A Systematic Review

BACKGROUND

Teriparatide, a 1-34 fragment of parathyroid hormone (PTH) that maintains most of the biological activities of PTH, has been employed since 2002 as an anabolic agent for osteoporotic individuals who are at high risk of fracture. The purpose of the present review is to provide a systematic summary and timely update on treatment with teriparatide for fracture prevention.

METHODS

Electronic databases, including OVID MEDLINE, OVID Embase, and the Cochrane Library, were searched on February 9, 2018, to identify published systematic reviews and meta-analyses addressing treatment with teriparatide for fracture prevention, and A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) was used to assess the quality of included studies.

RESULTS

Seventeen studies were included. Of the 17 eligible studies, 3 were rated as high quality, 3 were rated as moderate quality, 6 were rated as low quality, and 5 were rated as critically low quality. Teriparatide reduced vertebral and overall nonvertebral fractures in osteoporotic patients regardless of the existence of precipitating conditions, including postmenopausal status, glucocorticoid treatment, and chronic kidney disease, as compared with placebo, but not the site-specific nonvertebral fractures of the wrist and hip. Teriparatide did not more effectively reduce fracture risks when compared with other medications, such as bisphosphonates, selective estrogen receptor modulators, RANKL (receptor activator of nuclear factor kappa-beta ligand) inhibitor, or strontium ranelate.

CONCLUSIONS

Teriparatide was safe and was not associated with an increased rate of adverse events when compared with other drugs. Teriparatide was effective for the prevention of vertebral and overall nonvertebral fractures in osteoporotic patients but not for the prevention of site-specific nonvertebral fractures at the wrist and hip.

LEVEL OF EVIDENCE

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

A retrospective analysis of nonresponse to daily teriparatide treatment

Some patients with osteoporosis do not respond to teriparatide treatment. Prior bisphosphonate use, lower bone turnover marker (BTMs) concentrations, and lower early increases in BTMs were significantly associated with a blunted lumbar spine (LS) bone mineral density (BMD) response to daily treatment with teriparatide, although the impact was limited.

INTRODUCTION

Some osteoporosis patients do not respond to teriparatide treatment. To better understand the factors underlying treatment nonresponses, we compared nonresponders' and responders' characteristics.

METHODS

We retrospectively analyzed 354 male and female patients with osteoporosis who were administered teriparatide (20 μg/day) for 24 months. The patients were categorized as responders (≥3 % lumber spine (LS) bone mineral density (BMD) increase) or nonresponders (<3 % LS BMD increase), and the groups were compared.

RESULTS

The univariate analyses determined that prior bisphosphonate use, a lower baseline procollagen type I N-terminal propeptide (PINP) concentration and a lower urinary N-telopeptide of type I collagen (uNTX) concentration at baseline were significantly associated with teriparatide nonresponses, but these factors were not significant following multivariate analysis. Diminished early increases in the bone turnover markers (BTMs) were also related to nonresponses after teriparatide treatment began. In the nonresponders, the mean (standard deviation (SD)) absolute LS and femoral neck (FN) BMD changes were -0.002 g/cm(2) (0.032) and -0.010 g/cm(2) (0.045), respectively. In the responders, the mean (SD) absolute LS and FN BMD changes were 0.118 g/cm(2) (0.056) and 0.021 g/cm(2) (0.046), respectively. The serum PINP and uNTX levels increased rapidly in both groups, but the responders showed higher early absolute serum PINP and uNTX increases.

CONCLUSIONS

The factors associated with nonresponses were prior bisphosphonate use, lower baseline BTM levels, and lower early increases in the BTMs after starting teriparatide treatment, but the impact of these factors on achieving a ≥3 % LS BMD increase at 24 months was limited.

Single and combined use of human parathyroid hormone (PTH) (1-34) on areal bone mineral density (aBMD) in postmenopausal women with osteoporosis: evidence based on 9 RCTs

Background

Human parathyroid hormone (PTH) (1-34) or teriparatide (TPTD) is an anabolic agent for osteoporosis. This recombinant protein stimulates positive bone formation balance and bone remodeling. However, when concomitantly used with antiresorptive (AR) agents, previous studies reported conflicting results in their potential additive and synergistic effects on bone metabolism and bone mineral density (BMD). This study aimed to integrate previous evidence to assess the effect of TPTD monotherapy and the additive effect of TPTD on AR agents in postmenopausal women with osteoporosis.

Material/Methods

This meta-analysis identified 9 RCTs from databases. To assess the therapeutic effect on osteoporosis, the weighted mean differences (WMDs) were used to pool the percentage change of BMD along with the 95% confidence intervals (CIs). BMD of 3 skeletal sites, including lumbar spine, total hip, and femoral neck were assessed.

Results

TPTD alone could significantly improve BMD of all 3 skeletal sites compared with placebo, although the effect on the femoral neck was less conclusive. The additive effect of TPTD over hormone replacement therapy (HRT) and denosumab (DEN) agents is evident in all 3 skeletal sites. But TPTD plus Alendronate (ALN) did not demonstrate additive effect in total hip and femoral neck.

Conclusions

TPTD alone could significantly improve BMD of lumbar spine, total hip, and femoral neck. BMD outcomes of concomitant use of TPTD and AR agents are site-dependent and vary depending on the specific AR agent used and the timing of AR therapy initiation.

Teriparatide increases the insertional torque of pedicle screws during fusion surgery in patients with postmenopausal osteoporosis

Object

The object of this study was to examine the efficacy of preoperative teriparatide treatment for increasing the insertional torque of pedicle screws during fusion surgery in postmenopausal women with osteoporosis.

Methods

Fusion surgery for the thoracic and/or lumbar spine was performed in 29 postmenopausal women with osteoporosis aged 65–82 years (mean 72.2 years). The patients were divided into 2 groups based on whether they were treated with teriparatide (n = 13) or not (n = 16) before the surgery. In the teriparatide-treated group, patients received preoperative teriparatide therapy as either a daily (20 μg/day, n = 7) or a weekly (56.5 μg/week, n = 6) injection for a mean of 61.4 days and a minimum of 31 days. During surgery, the insertional torque was measured in 212 screws inserted from T-7 to L-5 and compared between the 2 groups. The correlation between the insertional torque and the duration of preoperative teriparatide treatment was also investigated.

Results

The mean insertional torque value in the teriparatide group was 1.28 ± 0.42 Nm, which was significantly higher than in the control group (1.08 ± 0.52 Nm, p < 0.01). There was no significant difference between the daily and the weekly teriparatide groups with respect to mean insertional torque value (1.34 ± 0.50 Nm and 1.18 ± 0.43 Nm, respectively, p = 0.07). There was negligible correlation between insertional torque and duration of preoperative teriparatide treatment (r2 = 0.05, p < 0.01).

Conclusions

Teriparatide injections beginning at least 1 month prior to surgery were effective in increasing the insertional torque of pedicle screws during surgery in patients with postmenopausal osteoporosis. Preoperative teriparatide treatment might be an option for maximizing the purchase of the pedicle screws to the bone at the time of fusion surgery.

Determinants associated with bone mineral density increase in response to daily teriparatide treatment in patients with osteoporosis

INTRODUCTION

Several factors associated with bone mineral density (BMD) increase are reported with daily teriparatide treatment, but there has been no systematic analysis to summarize these associations. The purpose of this study was to investigate the clinical determinants associated with BMD increase to daily teriparatide treatment.

METHODS

This was a retrospective study. We performed an analysis of 306 patients diagnosed with osteoporosis. Teriparatide was administered at 20μg/day for 12months. The primary efficacy measure was a change in lumbar spine (LS) BMD from baseline at 12months. To determine the response variables of BMD changes, we investigated the clinical determinants using univariate and multivariate analyses.

RESULTS

There was a 9.8±8.2% increase in LS BMD after 12months. Prior bisphosphonate treatment and baseline procollagen type I N-terminal propeptide (PINP) concentration were significantly associated with LS BMD absolute response by univariate analyses. In the multiple regression model, patients with higher baseline PINP concentration had a significantly greater LS BMD absolute increase. Prior bisphosphonate use lost its correlation in the multiple regression models.

CONCLUSION

Our results showed that baseline PINP concentration was a useful predictor of LS BMD absolute increase regardless of prior treatment.

Histone deacetylation mediates the rejuvenation of osteoblastogenesis by the combination of 25(OH)D3 and parathyroid hormone in MSCs from elders

Vitamin D metabolites are important effectors of bone and mineral homeostasis. Human bone marrow stromal cells (hMSCs) are targets of 1α,25-dihydroxyvitamin D [1α,25(OH)2D] action to promote their differentiation to osteoblasts. Osteoblastogenesis is also stimulated by 25-hydroxyvitamin D [25(OH)D], an effect that requires conversion to 1α,25(OH)2D3 by 25-hydroxyvitamin D3 1α-hydroxylase (CYP27B1). These findings support an autocrine/paracrine role of vitamin D metabolism in osteoblastogenesis of hMSCs. In this study, we assessed whether and by what mechanisms osteoblastogenesis could be rejuvenated with hMSCs from elders. First, knockdown studies with VDR-siRNA showed that both the pro-differentiation and anti-proliferative effects of 1α,25(OH)2D3 required VDR. Second, 100nM 25(OH)D3 (p<0.01 vs. control, ANOVA) and 100nM PTH1-34 (p<0.05) significantly stimulated alkaline phosphatase (ALP) activity (a measure of osteoblastogenesis), with a synergistic effect when combined (p<0.001). Scriptaid, an inhibitor of histone deacetylase, blocked the effect of 25(OH)D3 and PTH on osteoblastogenesis. Scriptaid alone downregulated VDR in hMSCs. These data demonstrate that histone deacetylation is required for the synergistic effect of 25(OH)D3 and PTH on osteoblastogenesis in hMSCs. Both VDR siRNA and Scriptaid dowregulated VDR mRNA and inhibited osteoblastogenesis. Thus, epigenetic regulation of the VDR may be central to rejuvenating osteoblastogenesis in hMSCs from elders. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

Vitamin D metabolism in human bone marrow stromal (mesenchymal stem) cells

There are many human extra-renal tissues and cells that biosynthesize 1α,25-dihydroxyvitamin D (1α,25(OH)(2)D) by the action of CYP27B1/1α-hydroxylase. Human marrow stromal cells (hMSCs), also known as mesenchymal stem cells, were isolated from marrow discarded from well-characterized, consented subjects during common orthopedic procedures. Human MSCs can give rise to osteoblasts, chondrocytes, adipocytes, and other lineages. Their in vitro differentiation to osteoblasts is stimulated by 1α,25(OH)(2)D, and recent evidence indicates that they have the capacity to metabolize vitamin D in a regulated manner. Human MSCs express the vitamin D receptor, 25-hydroxylases, 1α-hydroxylase, and 24-hydroxylase; stimulation of in vitro osteoblastogenesis by 25(OH)D depends on the activity of CYP27B1/1α-hydroxylase. The finding that hMSCs are a both a producer and target of 1α,25(OH)(2)D suggests a potential autocrine/paracrine role of vitamin D metabolism in osteoblast differentiation. Expression and enzyme activity of CYP27B1/1α-hydroxylase are upregulated by substrate 25(OH)D and Parathyroid Hormone (PTH) and are downregulated by 1α,25(OH)(2)D. With subject age, there are decreases in basal osteoblast potential and in stimulation of osteoblastogenesis by 1α,25(OH)(2)D, 25(OH)D, and PTH. In vitro treatment with a combination of 25(OH)D and PTH rejuvenated osteoblastogenesis with hMSCs from elders; this was attributable to increases in CYP27B1/1α-hydroxylase and in receptor for each hormone by the reciprocal factor. Other clinical variables beside age, i.e. low serum 25(OH)D or low estimated glomerular filtration rate, are correlated with reduced osteoblastogenesis. These studies suggest that osteoblastogenesis may not be optimal unless there is sufficient serum 25(OH)D substrate for hMSCs to synthesize and respond to local 1α,25(OH)(2)D.

The effectiveness of teriparatide in the clinical practice--attenuation of the bone mineral density outcome by increasing age and bisphosphonate pretreatment

BACKGROUND

Teriparatide is a potent anabolic agent for severe osteoporosis.

OBJECTIVES

A primary objective of this retrospective study was to define the efficacy of teriparatide in terms of bone mineral density (BMD) changes and relief of back pain in clinical practice.

METHODS

The patient population comprises 119 osteoporotic patients treated with teriparatide for median 539 (range 179-926) days.

RESULTS

The mean BMD gain was 0.9% in the total hip (P = 0.0075), 2.1% in the femoral neck (P = 0.0006), and 8.5% in the lumbar spine (P = 0.0085). In the whole patient population age associated inversely with BMD changes in the total hip (P = 0.019) and in the femoral neck (P = 0.0036). A history of significant bisphosphonate pretreatment (n = 90) reduced BMD response in the total hip (P = 0.039). The total exposure of any prior bisphosphonate was negatively correlated with BMD response in the total hip (P = 0.0421). Half of the patients reported relief of back pain during the treatment. Leg pain, nausea, and dizziness were most frequent adverse concerns.

CONCLUSIONS

Teriparatide works in clinical practice as well as in clinical trials. Younger subjects benefited more than older patients from teriparatide in the total hip and in the femoral neck. Bisphosphonate pretreatment attenuated teriparatide-induced BMD gain.

Application of pharmacokinetics-pharmacodynamics/clinical response modeling and simulation for biologics drug development

Biologics, specifically monoclonal antibody (mAb) drugs, have unique pharmacokinetic (PK) and pharmacodynamic (PD) characteristics as opposed to small molecules. Under the paradigm of model-based drug development, PK-PD/clinical response models offer critical insight in guiding biologics development at various stages. On the basis of the molecular structure and corresponding properties of biologics, typical mechanism-based [target-mediated drug disposition (TMDD)], physiologically based PK, PK-PD, and dose-response meta-analysis models are summarized. Examples of using TMDD, PK-PD, and meta-analysis in helping starting dose determination in first-in-human studies and dosing regimen optimization in phase II/III trials are discussed. Instead of covering the entirety of model-based biologics development, this review focuses on the guiding principles and the core mathematical descriptions underlying the PK or PK-PD models most used.