Can denosumab be a substitute, competitor, or complement to bisphosphonates?

Low bone mineral density: a primer for the spine surgeon

Within spinal surgery, low bone mineral density is associated with several postoperative complications, such as proximal junctional kyphosis, pseudoarthrosis, and screw loosening. Although modalities such as CT and MRI can be utilized to assess bone quality, DEXA scans, the "Gold Standard" for diagnosing osteoporosis, is not routinely included in preoperative workup. With an increasing prevalence of osteoporosis in an aging population, it is critical for spine surgeons to understand the importance of evaluating bone mineral density preoperatively to optimize postoperative outcomes. The purpose of this state-of-the-art review is to provide surgeons a summary of the evaluation, treatment, and implications of low bone mineral density in patients who are candidates for spine surgery.

Clinical Performance of Implant-Supported Prostheses in the Rehabilitation of Patients Previously Treated for Medication-Related Osteonecrosis of the Jaws (MRONJ): A Systematic Review

There is a lack of consensus on managing resultant bone and soft tissue defects or on restoring oral function and aesthetics following medication-related osteonecrosis of the jaws (MRONJ) lesion healing. This clinical challenge presents a dilemma for practitioners. Removable prostheses pose a recurrence risk if poorly fitted and may inadequately restore function or aesthetics in cases of significant bone defect. Dental implant-supported prostheses could enhance function and quality of life, though their risks and indications are not well-defined. This systematic review examines the clinical outcomes and complications associated with implant-supported rehabilitations post-MRONJ surgery. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations and it was pre-registered in the Prospective Register of Systematic Reviews (PROSPERO) (CRD42023492539).

Pharmacokinetics, pharmacodynamics, safety and immunogenicity of recombinant, fully human anti-RANKL monoclonal antibody (MW031) versus denosumab in Chinese healthy subjects: a single-center, randomized, double-blind, single-dose, parallel-controlled trial

BACKGROUND

MW031 is a biosimilar candidate of denosumab (Prolia®). This study aimed to compare the pharmacokinetics, pharmacodynamics, safety and immunogenicity of MW031 to denosumab in healthy Chinese participants.

RESEARCH DESIGN AND METHODS

In this single-center, randomized, double-blind, parallel-controlled, single-dose trial, participants were given 60 mg MW031 (N = 58) or denosumab (N = 61) by subcutaneous injection and observed for 140 days. The primary endpoint was the bioequivalence of PK parameters (Cmax, AUC0-∞), and secondary endpoints including PD parameter, safety, and immunogenicity.

RESULTS

A comparison of main PK parameters showed that the geometric mean ratios (GMR) (90% confidence intervals [CIs]) of AUC0-∞ and Cmax for MW031 over denosumab were 105.48% (98.96%, 112.43%) and 98.58% (92.78%, 104.75%), respectively. The inter-CV values of AUC0-∞ and Cmax for MW031 ranged from 19.9% to 23.1%. PD parameter (sCTX) in the MW031 and denosumab groups were similar, and the positivity rates of immunogenicity were 0% in both groups. This study also showed similar safety profiles in both groups, and there were no drug-related, high-incidence and previously unreported adverse reactions.

CONCLUSION

This trial confirmed similar pharmacokinetic profiles of MW031 and denosumab in healthy male participants, and pharmacodynamic profile, immunogenicity and safety were comparable for both drugs.

TRIAL REGISTRATION

NCT04798313; CTR20201149.

Association of Antiosteoporotic Medication Bisphosphonates and Denosumab with Primary Breast Cancer: An Electronic Health Record Cohort Study

Background: The risks of osteoporosis and breast cancer are increasing in elderly women. Bisphosphonates and denosumab are recommended for treatment of osteoporosis. They have different and overlapping pharmacodynamics and previous studies have shown conflicting results regarding their risk association with breast cancer. We intend to further look into this issue through a comparative study.

Methods: Electronic health records of 91,626 women older than 50 years with no previous history of malignancy and no nonbreast cancer during follow-up were retrieved from southern California and retrospectively analyzed using univariate, bivariate, and log-rank tests. Medication use, breast cancer risk, and associated demographic and clinical history were assessed.

Results: Over an average of 3.6 years follow-up, the breast cancer relative risks (RRs) counted after 365 days of latency are 1.12 (95% confidence interval [CI]: 0.64–1.97) for denosumab ever users and 0.37 (95% CI: 0.21–0.66) for bisphosphonates ever users, when covariates are comparable. The significant difference is supported by the Log-rank test (p = 0.0004). Excluding statins coprescribers, the breast cancer RR is 1.31 (0.71, 2.43) in denosumab group and 0.26 (0.11, 0.62) in bisphosphonates group. There is a reduced RR in statins ever users (0.47, 95% CI: 0.38–0.58), and the breast cancer risk difference is not significant between concomitant denosumab/statins and bisphosphonates/statins ever users with RR 0.65 (0.16, 2.58) versus 0.55 (0.26, 1.16), p = 0.692.

Conclusions: Our data support an association of lower breast cancer risk with bisphosphonates use in elderly women. We did not observe a lower breast cancer risk in denosumab group; however, our data revealed a potential lower breast cancer risk in denosumab users with concurrent statins use and this requires further study.

Systemic osteoprotegerin does not improve peri-implant bone volume or osseointegration in rabbits

Anti-RANKL (receptor activator of nuclear factor kappa-B ligand) agents function by blocking the differentiation of osteoclasts, thereby proving useful in the clinical management of postmenopausal osteoporosis. The effects of such agents on osseointegration is less well understood. The purpose of the current study was to investigate whether osteoprotegerin (OPG), an osteoclast inhibitor, enhances the known anabolic effects of mechanical loading (VEH) and intermittent PTH (iPTH) using a well-established rabbit model of osseointegration. In the first set of experiments, OPG was administered either alone or combined with iPTH to study its effects on measured bone mass. The second set of experiments was conducted using a higher dosage of OPG (10 mg/kg) to explore its early impact at the cellular and molecular levels. All subjects had mechanical load applied to the implant on one extremity, and no load applied on the contralateral side. In the first set of experiments, OPG alone decreased peri-implant bone mass compared to the mechanical loading group, whereas OPG + iPTH increased peri-implant bone mass compared to the OPG group. In the second set of experiments, high-dose OPG significantly decreased osteoclast number (-74.3%) at 1 week. However, this effect was not sustained as osteoclast number returned to baseline by 2 weeks. These results suggest that systemic administration of OPG does not enhance osseointegration, but rather has a detrimental effect.

Denosumab for Effective Tumor Size Reduction in Patients With Giant Cell Tumors of the Bone: A Systematic Review and Meta-Analysis

BACKGROUND

Denosumab is a human monoclonal antibody that has been used successfully in the treatment of giant cell tumors of bone. These tumors are rare and, in principle, benign, but they are highly aggressive, locally advanced, osteolytic bone tumors that can metastasize to the lungs. Denosumab is an effective treatment when these tumors cannot be surgically removed or when surgical resection is likely to lead to severe morbidity (eg, loss of limbs or joints). The aim of this systematic review and meta-analysis was to investigate patients with giant cell tumors of bone who experienced tumor progression during treatment with denosumab and to compare them with patients who experienced reduction of their giant cell tumors of bone during treatment with denosumab.

METHODS

Embase, Cochrane Library, and MEDLINE/PubMed databases were searched for trials submitted by January 7, 2020, that reported the efficacy and safety of denosumab in patients with giant cell tumors of bone.

RESULTS

Sixty studies were reviewed, involving a total of 1074 patients who had giant cell tumors of bone and were treated with denosumab. Of the 60 studies, 58% of the patients were from case series studies, 39% from open-label phase II studies, and 3% from case reports. The response rate for denosumab as a treatment for giant cell tumors of bone was 97.5%, with statistical significance (P < .0001). Pain in the limbs was statistically the most common adverse event for denosumab treatment in case series studies (P < .0001). No treatment-related deaths occurred in the reviewed studies.

CONCLUSION

Cumulative evidence supports the addition of surgery to optimal medical therapy with denosumab to reduce tumor size, clinical symptoms, and mortality among patients with giant cell tumors of bone.

Application of machine learning approaches for osteoporosis risk prediction in postmenopausal women

Many predictive tools have been reported for assessing osteoporosis risk. The development and validation of osteoporosis risk prediction models were supported by machine learning.

INTRODUCTION

Osteoporosis is a silent disease until it results in fragility fractures. However, early diagnosis of osteoporosis provides an opportunity to detect and prevent fractures. We aimed to develop machine learning approaches to achieve high predictive ability for osteoporosis risk that could help primary care providers identify which women are at increased risk of osteoporosis and should therefore undergo further testing with bone densitometry.

METHODS

We included all postmenopausal Korean women from the Korea National Health and Nutrition Examination Surveys (KNHANES V-1, V-2) conducted in 2010 and 2011. Machine learning models using methods such as the k-nearest neighbors (KNN), decision tree (DT), random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), artificial neural networks (ANN), and logistic regression (LR) were developed to predict osteoporosis risk. We analyzed the effect of applying the machine learning algorithms to the raw data and featuring the selected data only where the statistically significant variables were included as model inputs. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) were used to evaluate performance among the seven models.

RESULTS

A total of 1792 patients were included in this study, of which 613 had osteoporosis. The raw data consisted of 19 variables and achieved performances (in terms of AUROCs) of 0.712, 0.684, 0.727, 0.652, 0.724, 0.741, and 0.726 for KNN, DT, RF, GBM, SVM, ANN, and LR with fivefold cross-validation, respectively. The feature selected data consisted of nine variables and achieved performances (in terms of AUROCs) of 0.713, 0.685, 0.734, 0.728, 0.728, 0.743, and 0.727 for KNN, DT, RF, GBM, SVM, ANN, and LR with fivefold cross-validation, respectively.

CONCLUSION

In this study, we developed and compared seven machine learning models to accurately predict osteoporosis risk. The ANN model performed best when compared to the other models, having the highest AUROC value. Applying the ANN model in the clinical environment could help primary care providers stratify osteoporosis patients and improve the prevention, detection, and early treatment of osteoporosis.

Denosumab Related Osteonecrosis of Jaw: a Case Report

Background

This case report shows an affected postmenopausal patient with medicaments related osteonecrosis of the jaw injury associated with increased use of bisphosphonates and Prolia^® (denosumab) for the treatment of osteoporosis. The mechanism of action of the receptor activates the denosumab of the nuclear-kB factor binding and makes nuclear-kB Factor, reducing bone volume and reabsorption in the trabecular and cortical bones and, consequently, decreasing an incidence of fractures and maintaining a bone formation. The bone physiology regulated by the hormones calcitonin, parathormone and vitamin D also undergoes interference.

Methods

The injury was located around a dental implant in region #24 and #25 and the patient complained of pain, bleeding, oedema, and halitosis for more than two months, that the dental implant had been installed five years before. According to the clinical findings, the patient presented the exposed and necrotic bone in the region of #24 and #25 and with the radiographs found, it was observed as extensive bone destruction adjacent to the dental implant.

Results

Patient was referred to the maxillofacial surgeon that performed the removal of bone sequestration and dental implant in the region affected. After that, the patient has been accompanied for a year.

Conclusions

Patients taking medications for osteoporosis or cancer need to receive special attention from the dentist. Invasive procedures on the jaw bone of patients taking these medications may cause osteonecrosis of the jaw. When diagnosed, osteonecrosis of the jaw should be treated surgically in conjunction with antibiotic therapy and patients should be monitored.

Matrix Metalloproteinases in Bone Resorption, Remodeling, and Repair

Matrix metalloproteinases (MMPs) are the major protease family responsible for the cleavage of the matrisome (global composition of the extracellular matrix (ECM) proteome) and proteins unrelated to the ECM, generating bioactive molecules. These proteins drive ECM remodeling, in association with tissue-specific and cell-anchored inhibitors (TIMPs and RECK, respectively). In the bone, the ECM mediates cell adhesion, mechanotransduction, nucleation of mineralization, and the immobilization of growth factors to protect them from damage or degradation. Since the first description of an MMP in bone tissue, many other MMPs have been identified, as well as their inhibitors. Numerous functions have been assigned to these proteins, including osteoblast/osteocyte differentiation, bone formation, solubilization of the osteoid during bone resorption, osteoclast recruitment and migration, and as a coupling factor in bone remodeling under physiological conditions. In turn, a number of pathologies, associated with imbalanced bone remodeling, arise mainly from MMP overexpression and abnormalities of the ECM, leading to bone osteolysis or bone formation. In this review, we will discuss the functions of MMPs and their inhibitors in bone cells, during bone remodeling, pathological bone resorption (osteoporosis and bone metastasis), bone repair/regeneration, and emergent roles in bone bioengineering.