Rankl genetic deficiency and functional blockade undermine skeletal stem and progenitor cell differentiation.

BACKGROUND: Skeletal Stem Cells (SSCs) are required for skeletal development, homeostasis, and repair. The perspective of their wide application in regenerative medicine approaches has supported research in this field, even though so far results in the clinic have not reached expectations, possibly due also to partial knowledge of intrinsic, potentially actionable SSC regulatory factors. Among them, the pleiotropic cytokine RANKL, with essential roles also in bone biology, is a candidate deserving deep investigation. METHODS: To dissect the role of the RANKL cytokine in SSC biology, we performed ex vivo characterization of SSCs and downstream progenitors (SSPCs) in mice lacking Rankl (Rankl-/-) by means of cytofluorimetric sorting and analysis of SSC populations from different skeletal compartments, gene expression analysis, and in vitro osteogenic differentiation. In addition, we assessed the effect of the pharmacological treatment with the anti-RANKL blocking antibody Denosumab (approved for therapy in patients with pathological bone loss) on the osteogenic potential of bone marrow-derived stromal cells from human healthy subjects (hBMSCs). RESULTS: We found that, regardless of the ossification type of bone, osteochondral SSCs had a higher frequency and impaired differentiation along the osteochondrogenic lineage in Rankl-/- mice as compared to wild-type. Rankl-/- mice also had increased frequency of committed osteochondrogenic and adipogenic progenitor cells deriving from perivascular SSCs. These changes were not due to the peculiar bone phenotype of increased density caused by lack of osteoclast resorption (defined osteopetrosis); indeed, they were not found in another osteopetrotic mouse model, i.e., the oc/oc mouse, and were therefore not due to osteopetrosis per se. In addition, Rankl-/- SSCs and primary osteoblasts showed reduced mineralization capacity. Of note, hBMSCs treated in vitro with Denosumab had reduced osteogenic capacity compared to control cultures. CONCLUSIONS: We provide for the first time the characterization of SSPCs from mouse models of severe recessive osteopetrosis. We demonstrate that Rankl genetic deficiency in murine SSCs and functional blockade in hBMSCs reduce their osteogenic potential. Therefore, we propose that RANKL is an important regulatory factor of SSC features with translational relevance.

[Analysis of the efficacy and safety of bone disease treatment in patients with newly diagnosed multiple myeloma treated with denosumab or zoledronic acid].

Objective: This study investigated the efficacy and safety of denosumab (DENOS) versus zoledronic acid (ZOL) in the bone disease treatment of newly diagnosed multiple myeloma. Methods: The clinical data of 80 patients with myeloma bone disease (MBD) at the Fifth Medical Center of PLA General Hospital between March 1, 2021 and June 30, 2023 were retrospectively reviewed. Eighteen patients with severe renal impairment (SRI, endogenous creatinine clearance rate<30 ml/min) were treated with DENOS, and 62 non-SRI patients were divided into DENOS (30 patients) and ZOL group (32 patients) . Results: Hypocalcemia was observed in 26 (33%) patients, and 22 patients developed hypocalcemia during the first treatment course. The incidence of hypocalcemia in the non-SRI patients of DENOS group was higher than that in the ZOL group [20% (6/30) vs 13% (4/32), P=0.028]. The incidence of hypocalcemia in SRI was 89% (16/18). Multivariate logistic regression analysis revealed that endogenous creatinine clearance rate<30 ml/min was significantly associated with hypocalcemia after DENOS administration (P<0.001). After 1 month of antiresorptive (AR) drug application, the decrease in the serum ß-C-terminal cross-linked carboxy-telopeptide of collagen type I concentrations of SRI and non-SRI patients in the DENOS group were significantly higher than that in the ZOL group (68% vs 59% vs 27%, P<0.001). The increase in serum procollagen type Ⅰ N-terminal propeptide concentrations of patients with or without SRI in the DENOS group were significantly higher than that in the ZOL group (34% vs 20% vs 11%, P<0.05). The level of intact parathyroid hormone in each group increased after AR drug treatment. None of the patients developed osteonecrosis of the jaw and renal adverse events, and no statistically significant differences in the overall response rate, complete remission and stringent complete remission rates were found among the groups (P>0.05), and the median PFS and OS time were not reached (P>0.05) . Conclusions: In the treatment of MBD, DENOS minimizes nephrotoxicity and has strong AR effect. Hypocalcemia is a common adverse event but is usually mild or moderate and manageable.

Novel genetic mutation associated with hyperphosphatemic familial tumoral calcinosis/hyperostosis-hyperphosphatemia syndrome treated with denosumab: a case report.

In this case report, a novel N-acetylgalactosaminyltransferase 3 homozygous mutation (c.782 G>A; p.R261Q) associated with hyperphosphatemic familial tumoral calcinosis/hyperostosis-hyperphosphatemia syndrome is described. The patient had elbow, pelvis, and lower limb pain and a hard mass in the hip and olecranon regions. Increased levels of inorganic phosphorus (Pi) and C-reactive protein were observed. After treating the patient with conventional drugs, we tested denosumab, which reduced but did not normalize the Pi.

Combination therapy with immune checkpoint inhibitors and denosumab improves clinical outcomes in non-small cell lung cancer with bone metastases.

BACKGROUND: The concomitant use of denosumab and immune checkpoint inhibitor (ICI) treatment may have synergistic effects and enhance antitumor activity; however, this has not been fully evaluated. This study aimed to evaluate the clinical outcomes of non-small cell lung cancer (NSCLC) patients with bone metastases receiving combination therapy and to identify the best combination regimen. METHODS: Eighty-six NSCLC patients with bone metastases who received ICI treatment were enrolled in this study. The patients were divided into two groups; a denosumab combination group (D + ICI group; n = 47) and a non-combination group (non-D + ICI group; n = 39). The response rate (RR) for bone metastases, disease control rate (DCR), overall survival (OS), real world progression-free survival (rwPFS), and the incidence of immune-related adverse events (irAEs) were evaluated. Additionally, the time when denosumab treatment should commence and concomitant treatment duration were evaluated. RESULTS: The D + ICI group showed significantly better RR (40.4 % vs. 20.5 %, p = 0.01), DCR (67.3 % vs. 38.7 %, p = 0.02), OS (14.2 vs. 8.6 months, p = 0.02), and rwPFS (7.4 vs. 3.6 months, p < 0.01) than the non-D + ICI group; however, incidence of irAEs showed no difference (29.7 % vs. 12.8 %, p = 0.07). Although clinical outcomes did not differ regardless of whether denosumab was initiated before or after ICI treatment, the group that received concomitant denosumab for more than four months had significantly better RR (46.2 % vs. 17.4 %, p = 0.03), OS (20.3 vs. 3.8 months, p < 0.01), and rwPFS (10.9 vs. 2.8 months, p < 0.01) than the group that received concomitant denosumab for less than four months. However, the landmark analysis showed no significant differences in OS (20.4 vs. 12.7 months, p = 0.11) and rwPFS (22.8 vs. 11.2 months, p = 0.21), and the results of denosumab duration were influenced by long-term survivors. CONCLUSION: Denosumab showed favorable synergistic effects with ICI treatment and may significantly improve the response to bone metastasis and prognosis without increasing the incidence of irAEs.

Efficacy of denosumab treatment for lung metastasis secondary to proximal humerus chondroblastoma.

Chondroblastoma is a rare benign cartilaginous tumor that accounts for approximately 1% of bone tumors, but it can be associated with lung metastasis in extremely rare cases, leading to a poor prognosis and death. Herein, we report the case of a 19-year-old male patient who presented with an aggressive chondroblastoma of the proximal humerus and bilateral lung metastasis. The patient was treated with wide local resection, partial metastasectomy, and denosumab. Denosumab treatment was effective in controlling metastatic progression and preventing local recurrence.

Cumulative incidence and risk factors for medication-related osteonecrosis of the jaw during long-term prostate cancer management.

Bone-modifying agents (BMA) are extensively used in treating patients with prostate cancer with bone metastases. However, this increases the risk of medication-related osteonecrosis of the jaw (MRONJ). The safety of long-term BMA administration in clinical practice remains unclear. We aimed to determine the cumulative incidence and risk factors of MRONJ. One hundred and seventy-nine patients with prostate cancer with bone metastases treated with BMA at our institution since 2008 were included in this study. Twenty-seven patients (15%) had MRONJ during the follow-up period (median, 19 months; interquartile range, 9-43 months). The 2-year, 5-year, and 10-year cumulative MRONJ incidence rates were 18%, 27%, and 61%, respectively. Multivariate analysis identified denosumab use as a risk factor for MRONJ, compared with zoledronic acid use (HR 4.64, 95% CI 1.93-11.1). Additionally, BMA use at longer than one-month intervals was associated with a lower risk of MRONJ (HR 0.08, 95% CI 0.01-0.64). Furthermore, six or more bone metastases (HR 3.65, 95% CI 1.13-11.7) and diabetes mellitus (HR 5.07, 95% CI 1.68-15.2) were risk factors for stage 2 or more severe MRONJ. MRONJ should be considered during long-term BMA administration in prostate cancer patients with bone metastases.

Long-Term Bone Mineral Density Changes in Kidney Transplant Recipients Treated with Denosumab: A Retrospective Study with Nonequivalent Control Group.

Data on the effectiveness of denosumab on osteoporosis after kidney transplantation are limited. We investigated the long-term bone mineral density (BMD) changes in kidney transplant recipients (KTRs) treated with denosumab compared to untreated KTRs. We enrolled KTRs treated with denosumab 60 mg/6 months for 4 years. An untreated group of sex and age-matched KTRs with a 1:1 ratio was included. The primary outcome was BMD changes assessed by Dual-energy X-ray Absorptiometry over 4 years. Data on serum creatinine, alkaline phosphatase (ALP), parathyroid hormone, and 25-hydroxyvitamin D were collected. All patients received oral cholecalciferol and calcium supplementation. 23 denosumab-treated KTRs were enrolled, and 23 untreated KTRs. The median time from transplant to the start of denosumab was 4 years (range 0:24). The denosumab group showed a significant increase from baseline in BMD at the lumbar spine (LS) (9.0 ± 10.7%, p < 0.001), and total hip (TH) (3.8 ± 7.9%, p = 0.041). The untreated group showed a significant decrease at all sites (- 3.0 ± 7%, p = 0.041 at the LS; - 6.3 ± 9.2%, p = 0.003 at the TH; - 6.7 ± 9.3%, p = 0.003 at the FN). The between-group differences in percent BMD changes were statistically significant at all sites. Similar results were found for the respective Z-scores. The ALP serum levels significantly decreased from baseline only in the denosumab group, with a significant between-group difference (p = 0.032). No significant differences in serum creatinine, hypocalcaemic events or acute graft rejection rates were observed. Four years of denosumab therapy were associated with increased BMD in KTRs, while untreated KTRs showed significant BMD losses at all sites.

Secondary fracture prevention in Spanish primary care: results of the PREFRAOS Study.

This study demonstrated a large treatment gap in elderly subjects experiencing fragility fracture in Spanish primary care, a low treatment persistence among subjects who do receive treatment, and more than one-quarter having no follow-up visits post-fracture. These data highlight the need to improve secondary fracture prevention in primary care. PURPOSE: To describe osteoporosis (OP) treatment patterns and follow-up in subjects with fragility fracture seen in Spanish primary care (PC). METHODS: This observational, retrospective chart review included subjects aged ≥ 70 years listed in the centers' records (November 2018 to March 2020), with ≥ 1 fragility fracture and prior consultation for any reason; subjects who had participated in another study were excluded. Outcomes included OP treatments and follow-up visits post-fragility fracture. RESULTS: Of 665 subjects included, most (87%) were women; overall mean (SD) age, 82 years. Fewer than two thirds (61%) had received any prior OP treatment (women, 65%; men, 38%); of these, 38% had received > 1 treatment (women, 25%; men, 13%). Among treated subjects, the most frequent first-line treatments were alendronate (43%) and RANKL inhibitor denosumab (22%), with a higher discontinuation rate and shorter treatment duration observed for alendronate (discontinuation, 42% vs 16%; median treatment duration, 2.5 vs 2.1 years). Over one-quarter (26%) of subjects had no follow-up visits post-fragility fracture, with this gap higher in women than men (35% versus 25%). The most common schedule of follow-up visits was yearly (43% of subjects with a fragility fracture), followed by half-yearly (17%) and biennial (10%), with a similar trend in men and women. Most OP treatments were prescribed by PC physicians, other than teriparatide and zoledronate. CONCLUSIONS: Across Spanish PC, we observed a large gap in the treatment and follow-up of elderly subjects experiencing a fragility fracture. Our data highlights the urgent need to improve secondary fracture prevention in PC.

Too Much of a Good Thing: Severe Hypercalcemia Presenting with Lethargy and Kidney Failure.

INTRODUCTION: We present a case of a 58-year-old man with a history of laryngo-pharyngectomy including bilateral thyroidectomy due to hypopharyngeal cancer presenting with lethargy, acute kidney failure, and hypercalcemia. Milk alkali syndrome was diagnosed given the history of high-dose calcium / vitamin D supplementation after ruling out other causes of hypercalcemia. After initial treatment with normal saline, furosemide and denosumab, the patient developed severe symptomatic hypocalcemia as a rare adverse effect of denosumab.

Romosozumab in patients who experienced an on-study fracture: post hoc analyses of the FRAME and ARCH phase 3 trials.

Post hoc analysis of FRAME and ARCH revealed that on-study nonvertebral and vertebral fractures by Month 12 were less common in women initially treated with romosozumab versus placebo or alendronate. Recurrent fracture risk was also lower in romosozumab­treated patients, and there were no fracture­related complications. Results support continuing romosozumab treatment post­fracture. PURPOSE: Post hoc analysis evaluating efficacy and safety of romosozumab, administered in the immediate post­fracture period, in the FRAME and ARCH phase 3 trials. METHODS: In FRAME (NCT01575834) and ARCH (NCT01631214), postmenopausal women with osteoporosis were randomized 1:1 to romosozumab 210 mg monthly or comparator (FRAME, placebo; ARCH, alendronate 70 mg weekly) for 12 months, followed by antiresorptive therapy (FRAME, denosumab; ARCH, alendronate). In patients who experienced on-study nonvertebral or new/worsening vertebral fracture by Month 12, we report the following: fracture and treatment­emergent adverse event (TEAE) incidence through 36 months, bone mineral density changes (BMD), and romosozumab timing. Due to the sample sizes employed, meaningful statistical comparisons between treatments were not possible. RESULTS: Incidence of on-study nonvertebral and vertebral fractures by Month 12 was numerically lower in romosozumab- versus comparator-treated patients (FRAME, 1.6% and 0.5% versus 2.1% and 1.6%; ARCH, 3.4% and 3.3% versus 4.6% and 4.9%, respectively). In those who experienced on-study nonvertebral fracture by Month 12, recurrent nonvertebral and subsequent vertebral fracture incidences were numerically lower in patients initially treated with romosozumab versus comparator (FRAME, 3.6% [2/56] and 1.8% [1/56] versus 9.2% [7/76] and 3.9% [3/76]; ARCH, 10.0% [7/70] and 5.7% [4/70] versus 12.6% [12/95] and 8.4% [8/95], respectively). Among those with on-study vertebral fracture by Month 12, recurrent vertebral and subsequent nonvertebral fracture incidences were numerically lower with romosozumab versus comparator (FRAME, 0.0% [0/17] and 0.0% [0/17] versus 11.9% [7/59] and 8.5% [5/59]; ARCH, 9.0% [6/67] and 7.5% [5/67] versus 15.0% [15/100] and 16.0% [16/100], respectively). In patients with fracture by Month 12, no fracture­related complications were reported in romosozumab-treated patients. BMD gains were numerically greater with romosozumab than comparators. CONCLUSION: Data suggest support for the efficacy and safety of continuing romosozumab treatment following fracture. TRIAL REGISTRATIONS: NCT01575834; NCT01631214.

Sclerotic bone: a sign of bone reaction in patients with medication related osteonecrosis of the jaw.

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction associated with antiresorptive drugs such as bisphosphonates and denosumab. When dealing with advanced and/or multiple MRONJ lesions undergoing surgical therapy, the extent of surgery is often a topic of discussion. The aim of this study was to identify the differences in bone density in and around the MRONJ lesion before and after surgical treatment to evaluate the needed surgical extend of the modelling osteotomy. In this retrospective study 26 patients with MRONJ lesions that were surgically treated in our department were observed. Length, width and bone density were measured in panoramic radiograph pre and postoperatively with the Imaging processing software Sidexis and ImageJ (Fiji). The necrotic area, the surrounding sclerotic area as well as the healthy contralateral side were observed. Measurements were performed by two independent observers. Pearson correlation was calculated to determine the interobserver variability. Bone density was significantly reduced in the necrotic bone area compared to the healthy unaffected contralateral reference side. The sclerotic bone area surrounding the necrosis showed increased bone density compared to the contralateral unaffected reference side. The density of the sclerotic bone area was increased in the previously affected MRONJ area in the postoperative panoramic radiograph. The pre and postoperative density showed no significant correlation to healing behaviour. The focus of the modelling osteotomy in surgical treatment of mature MRONJ lesions should be predominantly on the parts that appear necrotic and less dense in the panoramic radiograph as sclerotic areas might be an expression of bone reaction.

Denosumab-induced bone changes in a child: a case report.

We present the case of a 9-year-old girl who developed striking bone changes following two years of denosumab therapy for giant cell lesions of the jaw.

Treatment of Osteoporosis in Men on Androgen Deprivation Therapy in Japan.

Background and Objectives: Androgen deprivation therapy (ADT) for prostate cancer has greatly improved treatment outcomes. As patient survival rates have increased, reports of decreased bone density and increased bone fractures as side effects of ADT have emerged. The prevalence of osteoporosis in Japanese men was 4.6%. The purpose of this study was to evaluate the effect of osteoporosis treatment in prostate cancer patients who underwent ADT in Japan. Materials and Methods: The subjects were 33 male patients who had undergone ADT for prostate cancer, who were noted to have decreased bone density. Mean age was 76.2 ± 7.7 years (64-87). Medications included vitamin D in one case, bisphosphonates (BP) in 27 cases, and denosumab in five cases. The evaluation method examined the rate of change in bone mineral density (BMD) before osteoporosis treatment and 1 year after. For comparison, a group without osteoporosis treatment intervention (n = 33) was selected, and matched for prostate cancer treatment and age. The rate of change in trabecular bone score (TBS) was also calculated. Results: The percentage changes in BMD before and 1 year after treatment were as follows: lumbar spine, 7.1 ± 5.8% in the treatment group versus -3.9 ± 4.1% in the no treatment group; femoral neck, 5.5 ± 6.2% in the treatment group versus -0.9 ± 3.9% in the no treatment group; total femur, 6.6 ± 6.4% in the treatment group versus the no treatment group which was -1.7 ± 3.2%. In all cases, there was a clear significant difference (p < 0.01). The percent change in TBS was further calculated in the same manner. There was no significant difference between the two groups: +1.7 ± 3.8% in the treated group versus +0.3 ± 4.1% in the untreated group. Conclusions: Osteoporosis treatment in Japanese patients with prostate cancer on ADT therapy was found to significantly increase BMD compared to the untreated group. BP and denosumab were found to be very effective in increasing BMD.

Characteristics of isatuximab-derived interference in serum protein electrophoresis and immunofixation, and an absence of sustained in vivo interference due to belantamab mafodotin and denosumab.

OBJECTIVES: Some therapeutic monoclonal antibodies, like daratumumab and elotuzumab, produce interfering monoclonal bands on serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE). Whether other common therapeutic antibodies also produce interference has not been systematically evaluated. DESIGN AND METHODS: SPEP/IFE from patients receiving isatuximab (48 patients), belantamab mafodotin (BM; 41), and denosumab (41) were retrospectively reviewed for therapeutic antibody interference. Cases exhibiting isatuximab interference were quantified and the maximum duration of isatuximab effect was evaluated. To characterize band position, neat human serum was spiked with BM or denosumab at supratherapeutic concentrations. Band migration patterns were compared on SPEP and IFE, with band position expressed relative to other constant protein fractions. RESULTS: Isatuximab-induced IFE interference was common (81.3 % of evaluated patients) with a maximum observed duration of 8 weeks. 10.4 % of isatuximab patients had IgG kappa monoclonal gammopathies that co-migrated with the drug; this subset could benefit from HYDRASHIFT 2/4 isatuximab testing. 8.3 % of IFE cases were negative for an isatuximab band but showed large, endogenous M-spikes migrating elsewhere. All patients in this group expired within 1 year of this finding. We hypothesize that an inability to detect isatuximab in this setting corresponds to a large residual myeloma burden that reduces isatuximab serum concentration. This observation may serve as a negative prognostic factor. Spiking studies demonstrated that BM and denosumab produce interference in vitro, but sustained interference was not observed in >40 treated patients. CONCLUSIONS: Therapeutic antibody interference in patients receiving isatuximab is common, and can persist for at least 8 weeks after administration. >10 % of patients receiving isatuximab may benefit from HYDRASHIFT testing post-therapy. In contrast, BM and denosumab fail to produce sustained interference in treated patients.

Denosumab and sclerotherapy for recurrent spinal aneurysmal bone cyst in a child.

Aneurysmal bone cyst (ABC) is a non-malignant, locally destructive, blood-filled lesion in the bone that tends to grow aggressively. A young girl presented with a rapid recurrence after aggressive surgery of a large symptomatic sacral-spinal ABC. After a multidisciplinary tumour board, she was successfully treated with sclerotherapy and monthly intravenous denosumab. The patient has maintained asymptomatic for over 36 months now and has returned to full activity and strength. She never required surgery and has had radiologic resolution of the lesions. Treatment of recurrent ABC requires a multidisciplinary team approach. We believe this to be the first report to use this combined therapy to provide an alternative to morbid surgery for children with ABCs.

The Evaluation and Management of Lung Metastases in Patients with Giant Cell Tumors of Bone in the Denosumab Era.

Giant cell tumor of bone (GCTB) is characterized by uncertain biological behavior due to its local aggressiveness and metastasizing potential. In this study, we conducted a meta-analysis of the contemporary literature to evaluate all management strategies for GCTB metastases. A combination of the terms "lung metastases", "giant cell tumor", "bone", "treatment", and "oncologic outcomes" returned 133 patients meeting our inclusion criteria: 64 males and 69 females, with a median age of 28 years (7-63), at the onset of primary GCTB. Lung metastases typically occur at a mean interval of 26 months (range: 0-143 months) after treatment of the primary site, commonly presenting as multiple and bilateral lesions. Various treatment approaches, including surgery, chemotherapy, radiotherapy, and drug administration, were employed, while 35 patients underwent routine monitoring only. Upon a mean follow-up of about 7 years (range: 1-32 years), 90% of patients were found to be alive, while 10% had died. Death occurred in 25% of patients who had chemotherapy, whereas 96% of those not treated or treated with Denosumab alone were alive at a mean follow-up of 6 years (range: 1-19 years). Given the typically favorable prognosis of lung metastases in patients with GCTB, additional interventions beyond a histological diagnosis confirmation may not be needed. Denosumab, by reducing the progression of the disease, can play a pivotal role in averting or delaying lung failure.