Case Report: Safety and Efficacy of Denosumab in Four Children With Noonan Syndrome With Multiple Giant Cell Lesions of the Jaw

Hypercalcemia in children induced by denosumab: a case report and an analysis of the FDA adverse event reporting system database

BACKGROUND

The potential risks of denosumab on pediatric patients have raised concerns about its safety. This article aims to analyze the adverse effects of denosumab in minors, with a specific focus on hypercalcemia.

RESEARCH DESIGN AND METHODS

A case study involving a child was analyzed. The OpenVigil 2.1 was utilized to extract adverse event data from the FAERS database, focusing on denosumab as the primary suspect drug in pediatric patients. The study also reviewed published cases of children developing hypercalcemia after discontinuing denosumab.

RESULTS

The incidence of denosumab induced hypercalcemia in individuals under 18 years old is significantly higher than the overall incidence. The signal value for hypercalcemia was higher in the male group and was highest in the adolescent group. Hypercalcemia usually appeared approximately 4 months after denosumab discontinuation. Males had a higher peak blood calcium level. Patients aged 0-11 years had a higher average peak serum calcium compared to aged 12-17 years.

CONCLUSIONS

This study highlights the risk of hypercalcemia after discontinuation of denosumab in minors, with young age and male gender identified as potential high-risk factors. These findings offer valuable safety warnings and preventative measures for the secure administration of this drug in pediatric populations.

Multiple central giant cell granuloma of the jaws: diagnostic signposts of Noonan syndrome and RASopathy

Noonan syndrome (NS) is a phenotypically variable inherited multi-system disorder. Maxillofacial findings can be diagnostic, especially in the evaluation of discrete facial dysmorphia. Diagnostic landmark findings of therapeutic relevance for the jaws such as central giant cell granuloma (CGCG) are rare in NS. However, recent molecular genetic studies indicate that these rare, benign lesions are neoplasms and more common in specific syndromes grouped under the umbrella term RASopathies. A specialist surgical diagnosis can be helpful in identifying the underlying disease. This report outlines diagnosis and treatment of a case of CGCG for which jaw diagnosis became the key to identifying a syndromic disease.

Management of RANKL-mediated Disorders With Denosumab in Children and Adolescents: A Global Expert Guidance Document

CONTEXT

Denosumab is an effective treatment for many receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated disorders but there are potential safety considerations and limited data to guide its use in children and adolescents.

OBJECTIVE

This document seeks to summarize the evidence and provide expert opinion on safe and appropriate use of denosumab in pediatric RANKL-mediated disorders.

PARTICIPANTS

Ten experts in pediatric bone and mineral medicine from 6 countries with experience in the use of denosumab participated in the creation of this document.

EVIDENCE

Data were sourced from the published literature, primarily consisting of case reports/series and review articles because of the lack of higher level evidence. Expert opinion of the authors was used substantially when no published data were available.

CONCLUSION

Denosumab is an effective treatment for RANKL-mediated disorders in children and adolescents but is often not curative and, in some cases, is best used in conjunction with surgical or other medical treatments. Careful multidisciplinary planning is required to define the goals of treatment and expert oversight needed to manage the risk of mineral abnormalities. Substantive, collaborative research efforts are needed to determine optimal treatment regimens and minimize risks.

Denosumab Therapy in Cherubism

Cherubism is a rare disorder characterized by proliferative fibro-osseous lesions that result in bilateral bony hyperplasia of the face. Management varies based on symptom severity and includes longitudinal follow-up, pharmacotherapy, and/or surgical debulking. Off-label treatment with denosumab, a human monoclonal antibody that binds RANKL and inhibits osteoclast function to reduce bone resorption, can be beneficial in suppressing the proliferation of bone to minimize the need for surgery and to control postoperative reproliferation. Close follow-up is needed to maintain appropriate electrolyte levels. The present case demonstrates the achievement of symptomatic control with denosumab in a child with severe refractory cherubism.

Current concepts in targeted therapies for benign tumors of the jaw - A review of the literature

The aim of our study was to review current concepts in targeted therapies for benign tumors of the jaw. Benign odontogenic and maxillofacial bone tumors often require radical surgery, with consequent morbidity that impacts patients' postsurgical quality of life. Currently, targeted therapies and novel nonsurgical therapeutics are being explored for management of non-resectable tumors, with the aim of avoiding surgery or minimizing surgical scope. However, data on clinical applications of targeted therapies for benign tumors of the jaw remain sparse. Therefore, a literature review was conducted, based on the PubMed database, which included in vivo human clinical studies describing clinical application of targeted therapy for benign tumor of the jaw. The review assessed the outcomes of BRAF and MEK inhibitors for treatment of ameloblastoma, RANKL monoclonal antibody for treatment of giant cell tumor, cherubism, aneurysmal bone cyst, and fibrous dysplasia, and tyrosine kinase inhibitor for treatment of odontogenic myxoma and cherubism. Targeted therapies decreased tumor size, slowed down tumor progression, and reduced bone pain. Surgery remains the gold standard, but targeted therapies are promising adjuvant or alternative treatment options for reducing tumor progression and morbidity of tumor surgery.

Denosumab Treatment Does Not Halt Progression of Bone Lesions in Multicentric Carpotarsal Osteolysis Syndrome

Here we report the use of denosumab, a monoclonal antibody against receptor activator of nuclear factor κB ligand (RANKL), as monotherapy for multicentric carpotarsal osteolysis syndrome (MCTO) in an 11.5-year-old male with a heterozygous missense mutation in MAFB (c.206C>T; p.Ser69Leu). We treated the subject with 0.5 mg/kg denosumab every 60-90 days for 47 months and monitored bone and mineral metabolism, kidney function, joint range of motion (ROM), and bone and joint morphology. Serum markers of bone turnover reduced rapidly, bone density increased, and renal function remained normal. Nevertheless, MCTO-related osteolysis and joint immobility progressed during denosumab treatment. Symptomatic hypercalcemia and protracted hypercalciuria occurred during weaning and after discontinuation of denosumab and required treatment with zoledronate. When expressed in vitro, the c.206C>T; p.Ser69Leu variant had increased protein stability and produced greater transactivation of a luciferase reporter under the control of the PTH gene promoter than did wild-type MafB. Based on our experience and that of others, denosumab does not appear to be efficacious for MCTO and carries a high risk of rebound hypercalcemia and/or hypercalciuria after drug discontinuation. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Denosumab for central giant cell granuloma in an Australian tertiary paediatric centre

BACKGROUND

Central giant cell granulomas (CGCG) are rare osteolytic, benign but often locally aggressive tumours of bone. Surgical curettage may not be possible in extensive lesions and resection carries high morbidity, especially in growing children, and previous medical therapies have had variable efficacy and high recurrence rates. Interruption of receptor activator of nuclear factor-kappa B ligand (RANKL) signalling holds promise as an effective therapeutic strategy for these tumours.

AIMS

To evaluate the efficacy and safety of our protocol for denosumab treatment of CGCG in children.

METHODS

Retrospective review of 4 patients treated with denosumab using a standardised protocol for CGCG in a tertiary paediatric centre. Denosumab 70 mg/m² was given 4-weekly, followed by 2 doses of zoledronate 0.025 mg/kg, aimed at preventing rebound hypercalcaemia.

RESULTS

Treatment of CGCG resulted in metabolic remission in all patients, but recurrence, detected by positron emission tomography (PET), occurred at 6 months in three patients and 12 months in one patient. Three patients developed symptomatic hypercalcaemia 4-5 months and one patient asymptomatic hypercalcaemia 7 months after cessation of denosumab, with 3 requiring additional bisphosphonate treatment.

CONCLUSIONS

Denosumab produced a radiological and metabolic response in our patients, but metabolic recurrence occurred in all patients. PET imaging was effective for monitoring treatment response and early detection of recurrence. Incidence of rebound hypercalcaemia in this paediatric cohort was high. We present proposed changes to our protocol with the aim of producing sustained remission and preventing rebound hypercalcaemia.

Translational Strategies to Target Metastatic Bone Disease

Metastatic bone disease is a common and devastating complication to cancer, confounding treatments and recovery efforts and presenting a significant barrier to de-escalating the adverse outcomes associated with disease progression. Despite significant advances in the field, bone metastases remain presently incurable and contribute heavily to cancer-associated morbidity and mortality. Mechanisms associated with metastatic bone disease perpetuation and paralleled disruption of bone remodeling are highlighted to convey how they provide the foundation for therapeutic targets to stem disease escalation. The focus of this review aims to describe the preclinical modeling and diagnostic evaluation of metastatic bone disease as well as discuss the range of therapeutic modalities used clinically and how they may impact skeletal tissue.

Drug Treatment of Low Bone Mass and Other Bone Conditions in Pediatric Patients

Osteoporosis may affect young individuals, albeit infrequently. In childhood, bone mass increases, reaching its peak between the second and third decades; then, after a period of stability, it gradually declines. Several conditions, including genetic disorders, chronic diseases, and some medications, can have an impact on bone homeostasis. Diagnosis in young patients is based on the criteria defined by the International Society for Clinical Densitometry (ISCD), published in 2013. High risk factors should be identified and monitored. Often simple interventions aimed to eliminate the underlying cause, to minimize the negative bone effects linked to drugs, or to increase calcium and vitamin D intake can protect bone mass. However, in selected cases, pharmacological treatment should be considered. Bisphosphonates remain the main therapeutic agent for children with significant skeletal fragility and are also useful in a large number of other bone conditions. Denosumab, an anti-RANKL antibody, could become a potential alternative treatment. Clinical trials to evaluate the long-term effects and safety of denosumab in children are ongoing.

A Unique Case of Aggressive Central Giant Cell Granuloma in a 10-Year-Old Boy With 16p13.11 Microdeletion Syndrome

Central giant cell granuloma (CGCG) is a rare disease characterized by sporadic, benign, intraosseous mandibular lesions of unknown etiology. Histologically, these lesions are indistinguishable from brown tumors of hyperparathyroidism and cherubism, and occasionally have been associated with different syndromes raising a question for genetic etiology. The CGCG has varied presentation ranging from nonaggressive and indolent to aggressive, destructive, and recurrent, often posing diagnostic and therapeutic challenges. Herein, we present the first case of a 10-year-old boy with CGCG and 16p13.11 microdeletion syndrome, highlight the diagnostic challenges inherent to this heterogeneous disorder, and discuss the genetics and treatment approaches of these complex lesions.

Hypercalcemia following discontinuation of denosumab therapy: A systematic review

Denosumab is a monoclonal antibody that has been approved to treat osteoporosis, skeletal metastasis, and giant cell tumor of bone in skeletally mature patients. Due to its potential adverse effects on normal bone growth, its use has not yet been approved in skeletally immature patients; however, the use of this agent in such patients with overt or dysregulated bone resorptive conditions has been explored in recent years. While most studies have proven the effectiveness of denosumab in controlling the progression of various disorders in skeletally immature patients, they have also revealed that refractory hypercalcemia often follows the discontinuation of denosumab treatment, raising a concern over the use of this agent in these patients. Thus, this study was designed to better understand the pathology of this condition through a systematic review of the published literature. Our analysis suggests that this condition has a potential male predisposition, that there is a correlation between the duration of denosumab treatment and patient age, and that this condition often occurs within 3 months after the last administration of denosumab in skeletally immature patients but is significantly less likely in adults. These results may further underscore that high bone formation and bone turnover rates are critically associated with hypercalcemia after the discontinuation of denosumab. In contrast, given that not all skeletally immature patients develop hypercalcemia, it is probable that other unidentified factors are involved in the pathology of this condition.

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Rebound hypercalcemia often follows denosumab cessation in juveniles.

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Although relatively rare, rebound hypercalcemia can occur in adults.

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Rebound hypercalcemia may have a male predisposition in juveniles.

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Treatment duration of denosumab required to trigger hypercalcemia correlates with age.

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Onset of hypercalcemia is significantly earlier in juveniles than in adults.

Successful denosumab treatment for central giant cell granuloma in a 9-year-old child

BACKGROUND

Denosumab is a nonsurgical treatment option for central giant cell granulomas (CGCG), especially in aggressive lesions.

CASE REPORT

We describe a 9-year-old girl with an aggressive maxillary CGCG successfully treated with denosumab, avoiding a mutilating surgery after intralesional corticosteroid injections failed, and the lesion continued to rapidly grow. During denosumab treatment, she developed a self-limiting area of osteonecrosis in the maxillary alveolar bone, which rapidly resolved after antibiotic therapy. Six months after denosumab discontinuation, a maxillary surgical recontour was performed. Two weeks after surgery, the patient presented vomiting, pallor, dehydration, but no fever. Blood tests revealed severe hypercalcemia and acute renal dysfunction. After discarding thyroid, parathyroid, and adrenal alterations, a diagnosis of severe rebound hypercalcemia after denosumab treatment was made. Treatment consisted of hyperhydration, calcium pamidronate, and methylprednisolone, restoring calcium levels to normal.

CONCLUSION

After 2 years of follow-up, she remains on orthodontic treatment, with no recurrences or other episodes of hypercalcemia.