Clinical experience with intravenous zoledronic acid in the treatment of male osteoporosis: evidence and opinions

Effect of Topical PTH 1-34 Functionalized to Biogran® in the Process of Alveolar Repair in Rats Submitted to Orchiectomy

(1) Background: There are many therapies for osteoporosis control and bone maintenance; anabolic drugs such as teriparatide and bone grafts help in the repair process and stimulate bone formation. Thus, the aim of the present study was to evaluate the behavior of repaired bone in the presence of PTH (teriparatide) associated with Biogran^® (biomaterial) through a sonochemical procedure after extraction in rats. (2) Methods: The insertion of Biogran^® with PTH in the alveolus was performed 30 days after incisor extraction. Euthanasia occurred after 60 days. (3) Results: The use of local treatment of PTH loaded with Biogran® in healthy rats promoted good results for micro-CT, with an increase in percentage and bone volume, number and trabecular separation and less total porosity. Greater immunostaining for Wnt, β-Catenin and osteocalcin proteins and lower expression for Thrombospondin-Related Adhesive Protein (TRAP), which shows an increase in the number of osteoblasts and inhibition of osteoclast action. However, the treated orchiectomized groups did not obtain such expressive results. (4) Conclusion: The use of Biogran^® with PTH improved alveolar repair in rats. However, new researches with more efficient doses must be studied to collaborate effectively with the formation of a quality bone after the orchiectomy.

Inhibition of zoledronic acid derivatives with extended methylene linkers on osteoclastogenesis involve downregulation of JNK and Akt pathways

Bisphosphonates (BPs), especially zoledronic acid (ZOL), are clinically used to treat osteolytic bone lesions. However, serious side-effects may be also induced during the therapeutic process. To improve the BPs drugs, here, we investigated the effects of a series of ZOL derivatives with increasing number of methylene linker between the imidazole ring and the P-C-P backbone named IPrDP, IBDP, IPeDP, and IHDP on cell viability and receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation, function and apoptosis induction in mouse bone marrow-derived macrophages (BMMs). Our results suggested that IPeDP and IHDP, which contains 4 and 5 methylene linkers, respectively, exerted lower toxicity on BMMs compared with ZOL, IPrDP, and IBDP, which contains 1, 2, and 3 methylene linkers respectively. At concentrations below cytotoxicity threshold, IPeDP and IHDP possessed strong abilities of antiosteoclast formation, antibone absorption, and inducing osteoclast apoptosis, which were similar to ZOL and more powerful than IPrDP and IBDP. The mechanism behind these effects of IPeDP and IHDP might involve the interference of small GTPases prenylation through suppression of mevalonate pathway. The downregulation of JNK and Akt phosphorylation and subsequent inhibition of the expression of c-Fos and NFATc1 might also be involved. Our results supported the potential usage of IPeDP and IHDP to treat bone-related disorders involving increased osteoclastogenesis. Our attempt to extend the methylene linker between the imidazole ring and the P-C-P backbone of ZOL also reveals some regularities between the structure and properties of the BPs drugs.

Comprehensive Study of the Risk Factors for Medication-Related Osteonecrosis of the Jaw Based on the Japanese Adverse Drug Event Report Database

Medication-related osteonecrosis of the jaw (MRONJ) is associated with many drugs, including bisphosphonates (BPs). BPs are associated with atypical femoral fractures and osteonecrosis of the external auditory canal. Thus, many drugs are reported to cause adverse effects on bone. This study aimed to investigate the effects of drugs and patient backgrounds regarding osteonecrosis-related side effects, including MRONJ. This study used a large voluntary reporting database, namely, the Japanese Adverse Drug Event Report database. First, we searched for risk factors related to MRONJ using volcano plots and logistic regression analysis. Next, we searched for bone-necrosis-related side effects using principal component and cluster analysis. Factors that were significantly associated with MRONJ included eight types of BPs and denosumab, prednisolone, sunitinib, eldecalcitol, raloxifene, letrozole, doxifluridine, exemestane, radium chloride, medroxyprogesterone, female, elderly, and short stature. Furthermore, antiresorptive agents (i.e., BPs and denosumab) tended to induce MRONJ and atypical femoral fractures by affecting osteoclasts. We believe these findings will help medical personnel manage the side effects of many medications.

Integrative Analysis of Genomics and Transcriptome Data to Identify Regulation Networks in Female Osteoporosis

Background: Osteoporosis is a highly heritable skeletal muscle disease. However, the genetic mechanisms mediating the pathogenesis of osteoporosis remain unclear. Accordingly, in this study, we aimed to clarify the transcriptional regulation and heritability underlying the onset of osteoporosis.

Methods: Transcriptome gene expression data were obtained from the Gene Expression Omnibus database. Microarray data from peripheral blood monocytes of 73 Caucasian women with high and low bone mineral density (BMD) were analyzed. Differentially expressed messenger RNAs (mRNAs) and long non-coding RNAs (lncRNAs) were identified. Differences in BMD were then attributed to several gene modules using weighted gene co-expression network analysis (WGCNA). LncRNA/mRNA regulatory networks were constructed based on the WGCNA and subjected to functional enrichment analysis.

Results: In total, 3,355 mRNAs and 999 lncRNAs were identified as differentially expressed genes between patients with high and low BMD. The WGCNA yielded three gene modules, including 26 lncRNAs and 55 mRNAs as hub genes in the blue module, 36 lncRNAs and 31 mRNAs as hub genes in the turquoise module, and 56 mRNAs and 30 lncRNAs as hub genes in the brown module. JUN and ACSL5 were subsequently identified in the modular gene network. After functional pathway enrichment, 40 lncRNAs and 16 mRNAs were found to be related to differences in BMD. All three modules were enriched in metabolic pathways. Finally, mRNA/lncRNA/pathway networks were constructed using the identified regulatory networks of lncRNAs/mRNAs and pathway enrichment relationships.

Conclusion: The mRNAs and lncRNAs identified in this WGCNA could be novel clinical targets in the diagnosis and management of osteoporosis. Our findings may help elucidate the complex interactions between transcripts and non-coding RNAs and provide novel perspectives on the regulatory mechanisms of osteoporosis.

Pharmacological evaluation of imidazole-derived bisphosphonates on receptor activator of nuclear factor-κB ligand-induced osteoclast differentiation and function

Bisphosphonates (BPs) have been commonly used in the treatment of osteolytic bone lesions, such as osteoporosis and osteogenesis imperfecta. However, serious side-effects can occur during the therapy. To search for novel potent BPs with lower side-effects, a series of imidazole-containing BPs (zoledronic acid [ZOL]; ZOL derivatives by substitution of the hydrogen at the 2-position on the imidazole ring with a methyl [MIDP], ethyl [EIDP], n-propyl [PIDP], or n-butyl group [BIDP]) were developed and the effects on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation were investigated using the murine macrophage RAW 264.7 cells at the protein, gene, and morphological and functional levels. Influences of these BPs on the cell growth and proliferation of RAW 264.7 were also studied in order to determine cytotoxicity. The results showed that PIDP significantly inhibited the RANKL-induced osteoclast formation in a dose-dependent fashion without inducing cytotoxicity under the concentration of 12.5 μM. It exerted remarkable suppressive effects on the development of actin rings, the bone resorption, and the expressions of osteoclastogenesis-related gene and protein markers. The down-regulation of c-Jun N-terminal kinase (JNK), protein kinase B (Akt), and inhibitor of nuclear factor kappa-B (IκB) phosphorylation in the early signaling event and subsequent inhibition of the expression of c-Fos and nuclear factor of activated T cells (NFATc1) might be involved in these effects. All these results indicated that PIDP might be a promising drug to treat bone-related disorders.

Effect of medications on prevention of secondary osteoporotic vertebral compression fracture, non-vertebral fracture, and discontinuation due to adverse events: a meta-analysis of randomized controlled trials

BACKGROUND

Bone loss with aging and menopause increases the risk of fragile vertebral fracture, osteoporotic vertebral compression fracture (OVCF). The fracture causes severe pain, impedes respiratory function, lower the quality of life, and increases the risk of new fractures and deaths. Various medications have been prescribed to prevent a secondary fracture, but few study summarized their effects. Therefore, we investigated their effects on preventing subsequent OVCF via meta-analyses of randomized controlled trials.

METHODS

Electronic databases, including MEDLINE, EMBASE, CENTRAL, and Web of Science were searched for published randomized controlled trials from June 2015 to June 2019. The trials that recruited participants with at least one OVCF were included. We assessed the risk of bias of every study, estimated relative risk ratio of secondary OVCF, non-vertebral fracture, gastrointestinal complaints and discontinuation due to adverse events. Finally, we evaluated the quality of evidence.

RESULTS

Forty-one articles were included. Moderate to high quality evidence proved the effectiveness of zoledronate (Relative Risk, RR: 0.34; 95% CI, 0.17-0.69, p = 0.003), alendronate (RR: 0.54; 95% CI: 0.43-0.68; p < 0.0001), risedronate (RR: 0.61; 95% CI: 0.51-0.73; p < 0.0001), etidronate (RR, 0.50; 95% CI, 0.29-0.87, p < 0.01), ibandronate (RR: 0.52; 95% CI: 0.38-0.71; p < 0.0001), parathyroid hormone (RR: 0.31; 95% CI: 0.23-0.41; p < 0.0001), denosumab (RR, 0.41; 95% CI, 0.29-0.57; p < 0.0001) and selective estrogen receptor modulators (Raloxifene, RR: 0.58; 95% CI: 0.44-0.76; p < 0.0001; Bazedoxifene, RR: 0.66; 95% CI: 0.53-0.82; p = 0.0002) in preventing secondary fractures. Moderate quality evidence proved romosozumab had better effect than alendronate (Romosozumab vs. alendronate, RR: 0.64; 95% CI: 0.49-0.84; p = 0.001) and high quality evidence proved that teriparatide had better effect than risedronate (risedronate vs. teriparatide, RR: 1.98; 95% CI: 1.44-2.70; p < 0.0001).

CONCLUSION

Zoledronate, alendronate, risedronate, etidronate, ibandronate, parathyroid hormone, denosumab and selective estrogen receptor modulators had significant secondary prevention effects on OVCF. Moderate quality evidence proved romosozumab had better effect than alendronate. High quality evidence proved PTH had better effect than risedronate, but with higher risk of adverse events.

Denosumab versus bisphosphonates in patients with advanced cancers-related bone metastasis: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Bone metastasis is reported to be associated with poor quality of life, and increased risk of hospitalization. We aim to synthesize evidence from published randomized controlled trials (RCTs) which compared the efficacy of denosumab versus bisphosphonates in patients with advanced cancers.

METHODS

We searched for all published RCTs in the following electronic databases: PubMed, Scopus, Web of Science, and Cochrane Central. Retrieved records were screened for eligibility. Time-to-event data were pooled as hazard ratio (HR) using the generic inverse-variance method and dichotomous data were pooled as relative risk (RR) in a random-effect model. We used Review Manager 5.3 for windows.

RESULTS

Six unique RCTs with a total of 7722 patients were included. Overall effect estimates favored denosumab group in comparison to intravenous (IV) bisphosphonates in the following terms: time to first skeletal-related events (HR 0.92, 95% CI [0.86, 0.98], p = 0.01), time to subsequent skeletal-related event (RR 0.92, 95% CI [0.86, 0.99], p = 0.03), and radiation to bone (RR 0.81, 95% CI [0.71, 0.92], p = 0.02). Denosumab group was associated with increased risk of grade 3 or 4 hypocalcaemia (RR 1.99, 95% CI [1.11, 3.54], p = 0.02) and reduced risk of renal impairment or toxicity (RR 0.75, 95% CI [0.61, 0.91], p = 0.003) in comparison to IV bisphosphonates group. Pooled studies were homogenous.

CONCLUSION

Denosumab showed a favorable significant impact on delaying the time to first skeletal-related event and reducing the incidence of radiation to the bone event in comparison to bisphosphonates, with similar efficacy regarding overall survival and time to disease progression. Further large-scale and long-term studies are needed to clarify the long-term efficacy and safety of both regimens.

Nano-Hydroxyapatite Bone Substitute Functionalized with Bone Active Molecules for Enhanced Cranial Bone Regeneration

The aim of this study was to synthesize and characterize a nano-hydroxyapatite (nHAP) and calcium sulfate bone substitute (NC) for cranioplasty. The NC was functionalized with low concentrations of bone morphogenetic protein-2 (BMP-2) and zoledronic acid (ZA) and characterized both in vitro and in vivo. In vitro studies included MTT, ALP assays, and fluorescent staining of Saos-2 (human osteoblasts) and MC3T3-E1 (murine preosteoblasts) cells cultured on NC. An in vivo study divided 20 male Wistar rats into four groups: control (defect only), NC, NC + ZA, and NC + ZA + rhBMP-2. The materials were implanted in an 8.5 mm critical size defect in the calvarium for 12 weeks. Micro-CT quantitative analysis was carried out in vivo at 8 weeks and ex vivo after 12 weeks. Mineralization was highest in the NC + ZA + rhBMP-2 group (13.0 ± 2.8 mm³) compared to the NC + ZA group (9.0 ± 3.2 mm³), NC group (6.4 ± 1.9 mm³), and control group (3.4 ± 1.0 mm³) after 12 weeks. Histological and spectroscopic analysis of the defect site provided a qualitative confirmation of neo-bone, which was in agreement with the micro-CT results. In conclusion, NC can be used as a carrier for bioactive molecules, and functionalization with rhBMP-2 and ZA in low doses enhances bone regeneration.

Minor post-extraction complications other than BRONJ in older patients on oral bisphosphonates - a retrospective study

BACKGROUND

Oral bisphosphonates (BP) have been prescribed widely in osteoporosis patients. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been reported as a major complication, but there is little information about minor complications.

OBJECTIVE

This retrospective study describes post-operative complications - other than BRONJ - associated with dental extractions in patients on oral BP and compares outcomes with patients not on oral BP.

METHODS

The study period was 2004-05 ending December 2005, prior to the introduction of protocols for minimising risks related to extractions in patients on BP therapy. Records of patients aged 60 years and over who underwent extractions during this period at Sydney Dental Hospital were examined and post-operative complications analysed.

RESULTS

There were 266 participants identified on oral BP therapy out of an available number of 3811 available files based retrospectively from records of 4126 participants who underwent extractions during the two-year period. In the oral BP group, 10% had complications compared with 2% in the non-oral BP group (p < 0.0001). This relationship remained significant even after adjusting for age, gender, operator, type and site of procedure. Delayed healing (36%) and exposed alveolar bone which required an intervention (31%) were the most common complications in the BP group.

CONCLUSION

The prevalence of minor post-operative complications among BP participants was significantly higher than in non-BP participants. The nature of the complications was in the range of pathology familiar to - and treatable by - the general dentist.

Analysis of the time-to-onset of osteonecrosis of jaw with bisphosphonate treatment using the data from a spontaneous reporting system of adverse drug events

Background

Bisphosphonates (BPs) are potent antiresorptive agents used to treat osteoporosis and the complications associated with malignant bone metastasis. The aim of this study was to evaluate the incidence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) using the Japanese Adverse Drug Event Report (JADER) database. In particular, we focused on the time-to-onset profile of BRONJ.

Findings

We analyzed reports of BRONJ in the JADER database and calculated the reporting odds ratio (ROR) of BPs potentially associated with BRONJ. We applied the weibull shape parameter to time-to-event data in JADER. The drugs selected for this investigation were seven BPs approved in Japan (alendronate [intraveneous, I.V.], pamidronate, and zoledronate as I.V. BPs; and alendronate (oral), etidronate, minodronate, and risedronate as oral BPs). We analyzed reports of BRONJ events associated with BPs in the JADER database from April 2004 to November 2014. The median value of BRONJ cases caused by alendronate (I.V.), pamidronate, zoledronate, alendronate (oral), etidronate, minodronate, and risedronate were 1342, 812, 486, 863, 1461, 432, and 730 days, respectively. The lower 95 % confidence interval of the Weibull-shape parameter β for I.V. BPs (pamidronate and zoledronate) exceeded 1. The risk of BRONJ with I.V. BPs increased over time.

Conclusion

Thus, the incidence of BRONJ with BP treatment should be closely monitored for a 3-year period. Further studies are required to draw conclusions, and we believe that this information about BRONJ induced by BPs will prove beneficial to patients and pharmacists.

Intraindividual comparison of preoperative (99m)Tc-MDP SPECT/CT and intraoperative and histopathological findings in patients with bisphosphonate- or denosumab-related osteonecrosis of the jaw

PURPOSE

Bisphosphonate- or denosumab-related osteonecrosis of the jaw (BRONJ/DRONJ) requires reliable preoperative assessment of the extent of disease for surgical planning. The aim of this study was to compare the extent of BRONJ/DRONJ as detected by Tc-99m-methylene diphosphonate (MDP) bone scintigraphy with intraoperative and histopathological findings, and to assess the additional value of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) for evaluation of disease.

MATERIAL AND METHODS

Twenty-one patients with BRONJ/DRONJ underwent three-phase bone scintigraphy including SPECT/CT. The diagnostic certainty using conventional SPECT or fused SPECT/CT imaging was compared. Location and extent of disease on scintigraphic imaging and pre- and intra-operative clinical assessment were compared. Intraoperative and histopathological findings served as reference standard.

RESULTS

A total of 29 sites of BRONJ/DRONJ were histopathologically confirmed in 21 patients. Bone scintigraphy demonstrated increased perfusion in 57.1% of patients, increased blood pool in 76.2%, and increased tracer accumulation at the metabolic phase in all patients. The intensity of tracer accumulation at the metabolic phase correlated significantly with clinical stage of disease (rs = 0.47, p = 0.03). Clinical examination (p < 0.0001), but not SPECT (p = 0.19), underestimated the extent of disease as determined by surgical evaluation. SPECT/CT offered a significantly higher diagnostic certainty (p < 0.0001).

CONCLUSION

In patients with BRONJ/DRONJ, the true extent of osseous lesions as determined by surgery is significantly underestimated by clinical examination. Tc-99m-MDP bone scintigraphy can reliably predict the extent of disease. Hybrid SPECT/CT may significantly increase the diagnostic certainty of anatomical localization.

Treatment of primary osteoporosis in men

With the aging of the population worldwide, osteoporosis and osteoporotic fractures are becoming a serious health care issue in the Western world. Although less frequent than in women, osteoporosis in men is a relatively common problem. Hip and vertebral fractures are particularly relevant, being associated with significant mortality and disability. Since bone loss and fragility fractures in men have been recognized as serious medical conditions, several randomized controlled trials (RCTs) have been undertaken in males with osteoporosis to investigate the anti-fracture efficacy of the pharmacological agents commonly used to treat postmenopausal osteoporosis. Overall, treatments for osteoporosis in men are less defined than in women, mainly due to the fact that there are fewer RCTs performed in male populations, to the relatively smaller sample sizes, and to the lack of long-term extension studies. However, the key question is whether men are expected to respond differently to osteoporosis therapies than women. The pharmacological properties of bisphosphonates, teriparatide, denosumab, and strontium ranelate make such differentiation unlikely, and available clinical data support their efficacy in men with primary osteoporosis as well as in women. In a series of well-designed RCTs, alendronate, risedronate, zoledronic acid, and teriparatide were demonstrated to reduce the risk of new vertebral fractures in men presenting with primary osteoporosis (including osteoporosis associated with low testosterone levels) and to improve the bone mineral density (BMD). In preliminary studies, ibandronate, denosumab, and strontium ranelate also showed their beneficial effects on surrogate outcomes (BMD and markers of bone turnover) in men with osteoporosis. Although direct evidence about their non-vertebral anti-fracture efficacy are lacking, the effects of bisphosphonates, denosumab, teriparatide, and strontium ranelate on surrogate outcomes (BMD and markers of bone turnover) were similar to those reported in pivotal RCTs undertaken in postmenopausal women, in which vertebral and non-vertebral anti-fracture efficacy have been clearly demonstrated. In conclusion, sufficient data exist to support the use of these pharmacological agents in men with primary osteoporosis. Further RCTs are warranted to establish their long-term efficacy and safety.