Zoledronic acid and risedronate in the prevention and treatment of glucocorticoid-induced osteoporosis (HORIZON): a multicentre, double-blind, double-dummy, randomised controlled trial.

BACKGROUND: Persistent use of glucocorticoid drugs is associated with bone loss and increased fracture risk. Concurrent oral bisphosphonates increase bone mineral density and reduce frequency of vertebral fractures, but are associated with poor compliance and adherence. We aimed to assess whether one intravenous infusion of zoledronic acid was non-inferior to daily oral risedronate for prevention and treatment of glucocorticoid-induced osteoporosis. METHODS: This 1-year randomised, double-blind, double-dummy, non-inferiority study of 54 centres in 12 European countries, Australia, Hong Kong, Israel, and the USA, tested the effectiveness of 5 mg intravenous infusion of zoledronic acid versus 5 mg oral risedronate for prevention and treatment of glucocorticoid-induced osteoporosis. 833 patients were randomised 1:1 to receive zoledronic acid (n=416) or risedronate (n=417). Patients were stratified by sex, and allocated to prevention or treatment subgroups dependent on duration of glucocorticoid use immediately preceding the study. The treatment subgroup consisted of those treated for more than 3 months (272 patients on zoledronic acid and 273 on risedronate), and the prevention subgroup of those treated for less than 3 months (144 patients on each drug). 62 patients did not complete the study because of adverse events, withdrawal of consent, loss to follow-up, death, misrandomisation, or protocol deviation. The primary endpoint was percentage change from baseline in lumbar spine bone mineral density. Drug efficacy was assessed on a modified intention-to-treat basis and safety was assessed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT00100620. FINDINGS: Zoledronic acid was non-inferior and superior to risedronate for increase of lumbar spine bone mineral density in both the treatment (least-squares mean 4.06% [SE 0.28] vs 2.71% [SE 0.28], mean difference 1.36% [95% CI 0.67-2.05], p=0.0001) and prevention (2.60% [0.45] vs 0.64% [0.46], 1.96% [1.04-2.88], p<0.0001) subgroups at 12 months. Adverse events were more frequent in patients given zoledronic acid than in those on risedronate, largely as a result of transient symptoms during the first 3 days after infusion. Serious adverse events were worsening rheumatoid arthritis for the treatment subgroup and pyrexia for the prevention subgroup. INTERPRETATION: A single 5 mg intravenous infusion of zoledronic acid is non-inferior, possibly more effective, and more acceptable to patients than is 5 mg of oral risedronate daily for prevention and treatment of bone loss that is associated with glucocorticoid use.

Effects of intravenous zoledronic acid once yearly on bone remodeling and bone structure.

UNLABELLED: In a substudy of the HORIZON pivotal fracture trial, in which yearly intravenous zoledronic acid 5 mg was found to significantly reduce risk of various fracture types in patients with postmenopausal osteoporosis, 152 patients underwent bone biopsy. Zoledronic acid reduced bone turnover by 63% and preserved bone structure and volume, with evidence of ongoing bone remodeling in 99% of biopsies obtained. INTRODUCTION: In the HORIZON pivotal fracture trial (PFT), enrolling 7,736 women with postmenopausal osteoporosis, three annual intravenous infusions of the bisphosphonate zoledronic acid (5 mg) significantly reduced morphometric vertebral, clinical vertebral, hip, and nonvertebral fractures by 70%, 77%, 41%, and 25%, respectively. Whereas 79% of patients received zoledronic acid/placebo only (stratum I, n = 6,113), 21% received concomitant treatment with other antiresorptive drugs, excluding other bisphosphonates, PTH, and strontium (stratum II, n = 1,652). MATERIALS AND METHODS: To determine effects on bone remodeling and bone architecture, iliac crest bone biopsies were obtained in 152 patients on active treatment or placebo at 3 yr after double tetracycline labeling. In five patients, only qualitative histology was performed, leaving 147 biopsy cores (79 on active treatment and 68 on placebo) for microCT analysis and histomorphometry. RESULTS: Analysis of bone structure by microCT revealed higher trabecular bone volume (BV/TV) in the zoledronic acid group (median, 16.6% versus 12.8%; p = 0.020). In addition, patients treated with zoledronic acid exhibited higher trabecular numbers (p = 0.008), decreased trabecular separation (p = 0.011), and a trend toward improvement in connectivity density (p = 0.062), all indicating better preservation of trabecular structure after treatment with zoledronic acid. Qualitative analysis revealed presence of tetracycline label in 81 of 82 biopsies from patients on zoledronic acid and all 70 biopsies from placebo patients, indicative of continued bone remodeling. No bone pathology was observed. Zoledronic acid induced a 63% median (71% mean) reduction of the activation frequency (Ac.f; p < 0.0001) and reduced mineralizing surface (MS/BS; p < 0.0001) and volume referent bone formation rate (BFR/BV) versus placebo, indicating reduced bone turnover. Mineral appositional rate was higher in the zoledronic acid group (p = 0.0002), suggesting improved osteoblast function compared with placebo. Mineralization lag time was similar in the two groups, whereas osteoid volume (OV/BV; p < 0.0001) and osteoid thickness (O.Th; p = 0.0094) were lower in zoledronic acid-treated patients, indicating normal osteoid formation and mineralization of newly formed bone. Concomitant administration of other antiresorptive osteoporosis therapies (e.g., raloxifene, tamoxifen, tibolone, ipriflavone) did not significantly alter the tissue level response to zoledronic acid. CONCLUSIONS: Annual dosing for 3 yr with zoledronic acid 5 mg intravenously resulted in a median 63% (mean, 71%) reduction of bone turnover and preservation of bone structure and mass without any signs of adynamic bone. Concomitant treatment with other osteoporosis therapies did not significantly affect the bone response to zoledronic acid.

Clinical evaluation of medicinal products for acceleration of fracture healing in patients with osteoporosis.

Pre-clinical studies indicate that pharmacologic agents can augment fracture union. If these pharmacologic approaches could be translated into clinical benefit and offered to patients with osteoporosis or patients with other risks for impaired fracture union (e.g. in subjects with large defects or open fractures with high complication rate), they could provide an important adjunct to the treatment of fractures. However, widely accepted guidelines are important to encourage the conduct of studies to evaluate bioactive substances, drugs, and new agents that may promote fracture union and subsequent return to normal function. A consensus process was initiated to provide recommendations for the clinical evaluation of potential therapies to augment fracture repair in patients with meta- and diaphyseal fractures. Based on the characteristics of fracture healing and fixation, the following study objectives of a clinical study may be appropriate: a) acceleration of fracture union, b) acceleration of return to normal function and c) reduction of fracture healing complications. The intended goal(s) should determine subsequent study methodology. While an acceleration of return to normal function or a reduction of fracture healing complications in and of themselves may be sufficient primary study endpoints for a phase 3 pivotal study, acceleration of fracture union alone is not. Radiographic evaluation may either occur at multiple time points during the healing process with the aim of measuring the time taken to reach a defined status (e.g. cortical bridging of three cortices or disappearance of fracture lines), or could be obtained at a single pre-determined timepoint, were patients are expected to reach a common clinical milestone (i.e. pain free full weight-bearing in weight-bearing fracture cases). Validated Patient Reported Outcomes (PRO's) measures will need to support the return to normal function co-primary endpoints. If reduction of complication rate (e.g. non-union) is the primary objective, the anticipated complications must be defined in the study protocol, along with their possible associations with the specified fracture type and fixation device. The study design should be randomized, parallel, double-blind, and placebo-controlled, and all fracture subjects should receive a standardized method of fracture fixation, defined as Standard of Care.

Prediction of hip fracture risk by quantitative ultrasound in more than 7000 Swiss women > or =70 years of age: comparison of three technologically different bone ultrasound devices in the SEMOF study.

UNLABELLED: To compare the prediction of hip fracture risk of several bone ultrasounds (QUS), 7062 Swiss women > or =70 years of age were measured with three QUSs (two of the heel, one of the phalanges). Heel QUSs were both predictive of hip fracture risk, whereas the phalanges QUS was not. INTRODUCTION: As the number of hip fracture is expected to increase during these next decades, it is important to develop strategies to detect subjects at risk. Quantitative bone ultrasound (QUS), an ionizing radiation-free method, which is transportable, could be interesting for this purpose. MATERIALS AND METHODS: The Swiss Evaluation of the Methods of Measurement of Osteoporotic Fracture Risk (SEMOF) study is a multicenter cohort study, which compared three QUSs for the assessment of hip fracture risk in a sample of 7609 elderly ambulatory women > or =70 years of age. Two QUSs measured the heel (Achilles+; GE-Lunar and Sahara; Hologic), and one measured the heel (DBM Sonic 1200; IGEA). The Cox proportional hazards regression was used to estimate the hazard of the first hip fracture, adjusted for age, BMI, and center, and the area under the ROC curves were calculated to compare the devices and their parameters. RESULTS: From the 7609 women who were included in the study, 7062 women 75.2 +/- 3.1 (SD) years of age were prospectively followed for 2.9 +/- 0.8 years. Eighty women reported a hip fracture. A decrease by 1 SD of the QUS variables corresponded to an increase of the hip fracture risk from 2.3 (95% CI, 1.7, 3.1) to 2.6 (95% CI, 1.9, 3.4) for the three variables of Achilles+ and from 2.2 (95% CI, 1.7, 3.0) to 2.4 (95% CI, 1.8, 3.2) for the three variables of Sahara. Risk gradients did not differ significantly among the variables of the two heel QUS devices. On the other hand, the phalanges QUS (DBM Sonic 1200) was not predictive of hip fracture risk, with an adjusted hazard risk of 1.2 (95% CI, 0.9, 1.5), even after reanalysis of the digitalized data and using different cut-off levels (1700 or 1570 m/s). CONCLUSIONS: In this elderly women population, heel QUS devices were both predictive of hip fracture risk, whereas the phalanges QUS device was not.

Dynamic mechanistic modeling of the multienzymatic one-pot reduction of dehydrocholic acid to 12-keto ursodeoxycholic acid with competing substrates and cofactors.

Ursodeoxycholic acid (UDCA) is a bile acid which is used as pharmaceutical for the treatment of several diseases, such as cholesterol gallstones, primary sclerosing cholangitis or primary biliary cirrhosis. A potential chemoenzymatic synthesis route of UDCA comprises the two-step reduction of dehydrocholic acid to 12-keto-ursodeoxycholic acid (12-keto-UDCA), which can be conducted in a multienzymatic one-pot process using 3α-hydroxysteroid dehydrogenase (3α-HSDH), 7ß-hydroxysteroid dehydrogenase (7ß-HSDH), and glucose dehydrogenase (GDH) with glucose as cosubstrate for the regeneration of cofactor. Here, we present a dynamic mechanistic model of this one-pot reduction which involves three enzymes, four different bile acids, and two different cofactors, each with different oxidation states. In addition, every enzyme faces two competing substrates, whereas each bile acid and cofactor is formed or converted by two different enzymes. First, the kinetic mechanisms of both HSDH were identified to follow an ordered bi-bi mechanism with EBQ-type uncompetitive substrate inhibition. Rate equations were then derived for this mechanism and for mechanisms describing competing substrates. After the estimation of the model parameters of each enzyme independently by progress curve analyses, the full process model of a simple batch-process was established by coupling rate equations and mass balances. Validation experiments of the one-pot multienzymatic batch process revealed high prediction accuracy of the process model and a model analysis offered important insight to the identification of optimum reaction conditions.

Determination of dynamic doxorubicin-EC50 value in an automated high-content workstation for cellular assays.

To overcome the problems of endpoint tests routinely required for EC50 determination, we utilized a novel automated high-content workstation and calculated a time-resolved EC50 value of MCF-7 mamma carcinoma cells treated with a pharmacologic agent. Measuring parameters were the cellular oxygen consumption and the extracellular acidification. These parameters were detected in real-time and label free with optochemical sensor spots in a modified 24-well sensor plate. In particular, the objective was to compare the measuring data of the workstation with a classical standard resazurin cell assay and to transfer the benefit of continuously recorded metabolic data of the workstation to practical time-resolved information about the effect of the applied active reagent (doxorubicin). MCF-7 cells were treated with a broad range of doxorubicin concentrations (100 µM to 1 nM) over 24 h and cellular activities were investigated with both, the resazurin assay and the automated workstation. Twenty-four hours after treatment, the resazurin assay showed an EC50 value (6.3 µM) which was about one decade above the value obtained from oxygen consumption rate (0.37 µM) and extracellular acidification rate (0.72 µM), measured with the workstation. Presumably, the differences are due to the different metabolic nature and regulation behind these measuring parameters. By polynomial fitting of continuously recorded metabolic data, we were able to point out a dynamic, time-resolved EC50 characteristic for different time points. The workstation is a powerful tool to record in vitro kinetic data of pharmacologic effects in vital cells in an automated experimental run.

The influence of chitosan valence on the complexation and transfection of DNA: the weaker the DNA-chitosan binding the higher the transfection efficiency.

The DNA-chitosan polyplexes have attracted for some years now the attention of physical-chemists and biologists for their potential use in gene therapy, however, the correlation between the physicochemical properties of these polyplexes with their transfection efficiency remains still unclear. In a recent paper we demonstrated by means of DLS that the DNA-chitosan complexation is favored at acidic conditions considering that fewer amounts of chitosan were required to compact the DNA. As a second study, in the present work we analyze the influence of chitosan valence on the complexation and transfection of DNA. Three chitosans of different molecular weights (three different valences) are characterized as gene carriers at 25°C and pH 5 over a wide range of chitosan-Nitrogen to DNA-Phosphate molar ratios, N/P, by means of conductometry, electrophoretic mobility, isothermal titration calorimetry (ITC), transmission electron microscopy (TEM), atomic force microscopy (AFM), and ß-galactosidase and luciferase expression assays.

[Practical proposals for the use of quantitative bone ultrasound in the management of osteoporosis]. / Propositions pratiques d'utilisation des ultrasons quantitatifs osseux dans le management de l'ostéoporose.

As an emerging alternative to DXA, there is a growing interest in the use of quantitative ultrasound (QUS) measurements for the non invasive assessment of fracture risk in the management of osteoporosis. While the potential of QUS in the management of osteoporosis have been highly recognized by the scientific community and granted by the majority of the international bone disease organizations, it becomes important to develop strategies how to use ultrasound clinically. Our paper is highlighting Swiss operational clinical propositions for 2 QUS devices sold in Switzerland, on how to use the QUS in the management of osteoporosis.