Use and safety of denosumab in cancer patients

External Validation and Update of the Risk Prediction Model for Denosumab-Induced Hypocalcemia Developed From a Hospital-Based Administrative Database

PURPOSE

Denosumab is used to treat patients with bone metastasis from solid tumors, but sometimes causes severe hypocalcemia, so careful clinical management is important. This study aims to externally validate our previously developed risk prediction model for denosumab-induced hypocalcemia by using data from two facilities with different characteristics in Japan and to develop an updated model with improved performance and generalizability.

METHODS

In the external validation, retrospective data of Kameda General Hospital (KGH) and Miyagi Cancer Center (MCC) between June 2013 and June 2022 were used and receiver operating characteristic (ROC)-AUC was mainly evaluated. A scoring-based updated model was developed using the same data set from a hospital-based administrative database as previously employed. Selection of variables related to prediction of hypocalcemia was based on the results of external validation.

RESULTS

For the external validation, data from 235 KGH patients and 224 MCC patients were collected. ROC-AUC values in the original model were 0.879 and 0.774, respectively. The updated model consisting of clinical laboratory tests (calcium, albumin, and alkaline phosphatase) afforded similar ROC-AUC values in the two facilities (KGH, 0.837; MCC, 0.856).

CONCLUSION

We developed an updated risk prediction model for denosumab-induced hypocalcemia with small interfacility differences. Our results indicate the importance of using data from plural facilities with different characteristics in the external validation of generalized prediction models and may be generally relevant to the clinical application of risk prediction models. Our findings are expected to contribute to improved management of bone metastasis treatment.

Severe Refractory Hypocalcemia Caused by Denosumab

Denosumab is a fully human monoclonal antibody that binds to the receptor activator of nuclear factor kappa-Β ligand, an essential cytokine factor in bone resorption, which reduces bone resorption and has been shown to decrease the incidence of skeletal-related events in patients with malignancy and bone metastasis. Severe hypocalcemia is a rare and life-threatening adverse effect of denosumab therapy. Here, we discuss the case of a patient with stage 4 estrogen receptor-positive, progesterone receptor-negative, human epidermal growth factor receptor 2-negative breast cancer who was on treatment with denosumab for bony metastases and presented with severe refractory hypocalcemia.

Denosumab in the treatment of giant cell tumor of the spine. Preliminary report, review of the literature and protocol proposal

BACKGROUND

The interest on the role of Denosumab in the treatment strategy of giant cell tumor of the spine is growing. En bloc resection is considered the Enneking appropriate treatment, but morbidity and functional loss are sometimes unacceptable. Denosumab could play a role as a stand-alone treatment, but also as preoperative treatment or as postoperative after intralesional surgery.

MATERIALS AND METHODS

A cohort of 10 out of 12 cases of spinal GCT consecutively treated with Denosumab are analyzed and discussed compared to the cases reported in the literature. A staging of the radiological effect of the treatment is proposed.

RESULTS

The stand-alone and postoperative treatments are still running (12 to 88 months). One therapy was stopped after 15 months, once a satisfactory local effect was achieved, but the treatment had to be restarted 2 months later due to the recurrence of the erosive images. The new treatment was successful. At 1-year follow-up after the gross total excision followed by postoperative Denosumab treatment, no evidence of local recurrence was found. The preoperative treatment duration ranged from 3 to 24 months. No local recurrence followed the en bloc resections.

CONCLUSIONS

Denosumab alone is effective in relieving pain, increasing the ossification and sometimes reducing the tumor volume. It can be considered an excellent solution in spine GCTs whose surgical treatment cannot be Enneking appropriate or is associated with unacceptable morbidity or loss of functions. It is still impossible to state when to safely stop the treatment. Denosumab also plays a role as preoperative protocol. These slides can be retrieved under Electronic Supplementary Material.

Prevention of breast cancer-induced osteolytic bone resorption by benzyl isothiocyanate

Osteolytic bone resorption is the primary cause of pain and suffering (e.g. pathological bone fracture) in women with metastatic breast cancer. The current standard of care for patients with bone metastasis for reducing the incidence of skeletal complications includes bisphosphonates and a humanized antibody (denosumab). However, a subset of patients on these therapies still develops new bone metastasis or experiences adverse effects. Moreover, some bisphosphonates have poor oral bioavailability. Therefore, orally-bioavailable and non-toxic inhibitors of breast cancer-induced osteolytic bone resorption are still clinically desirable. We have shown previously that benzyl isothiocyanate (BITC) decreases the incidence of breast cancer in a transgenic mouse model without any side effects. The present study provides in vivo evidence for inhibition of breast cancer-induced osteolytic bone resorption by BITC. Plasma achievable doses of BITC (0.5 and 1 μM) inhibited in vitro osteoclast differentiation induced by co-culture of osteoclast precursor cells (RAW264.7) and breast cancer cells representative of different subtypes. This effect was accompanied by downregulation of key mediators of osteoclast differentiation, including receptor activator of nuclear factor-κB ligand and runt-related transcription factor 2 (RUNX2), in BITC-treated breast cancer cells. Doxycycline-inducible knockdown of RUNX2 augmented BITC-mediated inhibition of osteoclast differentiation. Oral administration of 10 mg BITC/kg body weight, 5 times per week, inhibited MDA-MB-231-induced skeletal metastasis multiplicity by ~81% when compared with control (P = 0.04). The present study indicates that BITC has the ability to inhibit breast cancer-induced osteolytic bone resorption in vivo.

Hypocalcaemia in patients with prostate cancer treated with a bisphosphonate or denosumab: prevention supports treatment completion

Background

Most patients with advanced prostate cancer develop bone metastases, which often result in painful and debilitating skeletal-related events. Inhibitors of bone resorption, such as bisphosphonates and denosumab, can each reduce the incidence of skeletal-related events and delay the progression of bone pain. However, these agents are associated with an increased risk of hypocalcaemia, which, although often mild and transient, can be serious and life-threatening. Here we provide practical advice on managing the risk of hypocalcaemia in patients with advanced prostate cancer who are receiving treatment with bone resorption inhibitors. Relevant references for this review were identified through searches of PubMed with the search terms ‘prostate cancer’, ‘bone-targeted agents’, ‘anti-resorptive agents’, ‘bisphosphonates’, ‘zoledronic acid’, ‘denosumab’, ‘hypocalcaemia’, and ‘hypocalcemia’. Additional references were suggested by the authors.

Main text

Among patients with advanced cancer receiving a bisphosphonate or denosumab, hypocalcaemia occurs most frequently in those with prostate cancer, although it can occur in patients with any tumour type. Consistent with its greater ability to inhibit bone resorption, denosumab has shown superiority in the prevention of skeletal-related events in patients with bone metastases from solid tumours. Consequently, denosumab is more likely to induce hypocalcaemia than the bisphosphonates. Likewise, various bisphosphonates have differing potencies for the inhibition of bone resorption, and thus the risk of hypocalcaemia varies between different bisphosphonates. Other risk factors for the development of hypocalcaemia include the presence of osteoblastic metastases, vitamin D deficiency, and renal insufficiency. Hypocalcaemia can lead to treatment interruption, but it is both preventable and manageable. Serum calcium concentrations should be measured, and any pre-existing hypocalcaemia should be corrected, before starting treatment with inhibitors of bone resorption. Once treatment has started, concomitant administration of calcium and vitamin D supplements is essential. Calcium concentrations should be monitored during treatment with bisphosphonates or denosumab, particularly in patients at high risk of hypocalcaemia. If hypocalcaemia is diagnosed, patients should receive treatment with calcium and vitamin D.

Conclusion

With preventative strategies and treatment, patients with prostate cancer who are at risk of, or who develop, hypocalcaemia should be able to continue to benefit from treatment with bisphosphonates or denosumab.

Serum levels of RANKL and OPG, and the RANKL/OPG ratio in bisphosphonate-related osteonecrosis of the jaw: Are they useful biomarkers for the advanced stages of osteonecrosis?

Background

We determined whether serum levels of Receptor Activator for Nuclear Factor κ B Ligand (RANKL), Osteoprotegerin (OPG), and the RANKL/OPG ratio could be useful biomarkers for the severity of oral lesions in bisphosphonate-related osteonecrosis of the jaw (BRONJ).

Material and Methods

A case-control study in which Group 1 consisted of 41 patients with BRONJ due to intravenous bisphosphonates, and Group 2 consisted of 44 healthy control cases. The plasma levels of RANKL and OPG were analyzed by an ELISA assay. The OPG/RANKL ratio was also calculated. We determined if the mean serum values differed among the different stages of BRONJ.

Results

Serum levels of RANKL were lower in Group 1 than in Group 2 (p =0.01), and serum levels of OPG were higher in patients with BRONJ than in the controls (p =0.006). The ratio of RANKL/OPG was greater in the controls than in Group 1 (P >0.01). There were no significant differences in the serum levels of RANKL and OPG among the different stages of osteonecrosis (P > 0.05).

Conclusions

Serum levels of RANKL and OPG, and the RANKL/OPG ratio were not valuable biomarkers for determining the severity of oral lesions in patients with BRONJ.

Key words:Bisphosphonates, RANKL, OPG, Osteonecrosis.