The effects of denosumab on calcium profiles in advanced cancer patients with bone metastases

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.

Recurrent severe hypocalcemia following chemotherapy regimen changes in advanced breast cancer: two case reports

BACKGROUND

As an oncologic emergency related to abnormalities in calcium metabolism, hypercalcemia associated with paraneoplastic syndrome and bone metastases is well known. Meanwhile, the incidence of hypocalcemia is low, except in cases associated with bone-modifying agents used for bone metastases. Hypocalcemia induced by bone-modifying agents typically occurs early after the initial administration, and its incidence can be significantly reduced by preventive administration of calcium and vitamin D3 supplements.

CASE REPORT

We report two cases of recurrent severe hypocalcemia occurring during chemotherapy for metastatic breast cancer with multiple bone metastases. Case 1: A 35-year-old Japanese woman developed metastases in the bone, liver, and ovaries during postoperative endocrine therapy for invasive lobular carcinoma of the breast. She underwent chemotherapy and treatment with denosumab. She experienced recurrent episodes of severe hypocalcemia subsequent to a change in the chemotherapy regimen. Case 2: A 65-year-old Japanese woman encountered multiple bone metastases after postoperative anti-human epidermal growth factor receptor 2 therapy and during endocrine therapy for invasive ductal carcinoma of the breast. She underwent anti-human epidermal growth factor receptor 2 therapy and treatment with denosumab. She experienced recurrent severe hypocalcemia subsequent to a change in the chemotherapy regimen to letrozole + lapatinib, trastuzumab emtansine, and lapatinib + capecitabine.

CONCLUSIONS

We observed two cases of recurrent severe hypocalcemia in patients with advanced breast cancer and bone metastases after modifications to their therapy regimens. These cases differed from the typical hypocalcemia induced by bone-modifying agents. It is possible that antitumor drugs affect calcium and bone metabolism associated with bone metastases. While these cases are rare, it is crucial for oncologists to be aware of hypocalcemia not only at the initiation of bone-modifying agents but also throughout the entire antitumor therapy, as hypocalcemia can lead to fatal outcomes.

Evaluation of denosumab in adult oncology patients for the prevention of skeletal related events across a large academic health system

INTRODUCTION

Denosumab (Xgeva^®) and zoledronic acid (Zometa^®) are widely utilized for prevention of skeletal related events (SREs) in oncology patients. Drug costs, renal function, ease and logistics of administration, and adverse effect profile are factors frequently considered by patients and/or providers when selecting an optimal agent. Given the significantly higher drug cost of denosumab compared to zoledronic acid, an evaluation of our institution's denosumab use and investigation into opportunities to shift denosumab administrations to zoledronic acid and/or to lower cost sites-of-care was warranted.

METHODS

A single-center, multi-site, retrospective, observational analysis of the electronic medical record (EMR) was conducted for adult oncology patients who received denosumab 120 mg for prevention of SREs from October 1st, 2018 to September 30th, 2019 at three institutions within our health system. Additional information was collected to characterize the patient population based on cancer diagnosis, renal function, and concomitant calcium and vitamin D supplementation. Our primary objective was to evaluate if the use of denosumab met current formulary restrictions of the health system.

RESULTS

In total, 304 adult oncology patients received 1411 doses of denosumab for the prevention of SREs. The majority of reviewed patients had a primary oncology diagnosis of breast (35%) or lung (24%) cancer. Of the patients who received denosumab, 278 (93%) met the health system's current formulary restrictions. The majority of patients who did not meet formulary restrictions were those with multiple myeloma (MM) (20/22; 91%). Of the 304 patients reviewed, 70 had the appropriate parameters in the EMR to calculate creatinine clearance (CrCl) using Cockcroft-Gault Equation. Of those 70 patients, 59 (84%) would have been eligible to receive zoledronic acid instead of denosumab given that their CrCl >30 mL/min with no documented intolerance to bisphosphonates. Concurrent use of calcium and vitamin D is recommended when using denosumab. Based on the most recent prior to admission (PTA) medication list obtained from the 304 patients evaluated, 222 (73%) had both calcium and vitamin D listed as "taking".

CONCLUSIONS

Within our health system, denosumab is restricted to those who meet formulary restrictions. Additional education is recommended to help limit the use of denosumab, specifically in MM, to reduce drug costs when zoledronic acid is also an appropriate first-line agent.

The relationship between chronic kidney disease and denosumab-induced hypocalcemia in high-age osteoporotic patients

PURPOSE

A few studies have reported the safety of the treatment of elderly osteoporotic patients with chronic kidney disease (CKD) and the possibility of hypocalcemia. The aim of the present study was to examine the relationship between the incidence of hypocalcemia and the CKD stage in elderly osteoporotic patients treated with denosumab.

MATERIALS AND METHODS

This study was designed as a parallel-group comparison study between the denosumab-associated hypocalcemia (DAH) groups: the concentration of serum calcium was under 8.6 mg/dl and the normal calcium (NC) groups: the concentration of serum calcium was over 8.6 mg/dl. Fifty-two subjects over 70 years old were enrolled in this study, with 16 patients classified into the DAH group and 36 patients assigned to the NC group. All patients were further classified into two subgroups according to their age, into an around 75 years group to clarify the relevance of old age and an around 85 years group and also into a mild CKD group and a moderate CKD group by based on estimated glomerular filtration (eGFR). Serum calcium concentration, tartrate-resistant acid phosphatase (TRACP-5b), and type 1 procollagen N terminal propeptide (P1NP) were measured, and adverse drug reactions were evaluated.

RESULTS

The eGFR and serum calcium were significantly lower in the DAH group than in the NC group in the starting phase. Moreover, TRACP-5b was significantly higher in the DAH group than in the NC group in the starting phase. There were no significant differences in P1NP. The incidence of hypocalcemia was significantly higher in the around 85 groups than in the around 75 groups. The frequency of hypocalcemia was also significantly higher in the severe CKD group than in the mild CKD group.

CONCLUSION

Advanced age combined with low eGFR and low serum Ca status appear to be associated with the incidence of hypocalcemia when using denosumab for the treatment of osteoporosis.

Denosumab-induced hypocalcemia in a patient with hyperthyroidism: a case report

Denosumab is a humanized monoclonal antibody targeting the receptor activator of nuclear factor kappa-B ligand (RANKL). Denosumab is an effective treatment for osteoporosis but can cause hypocalcemia. We present a case of denosumab-induced hypocalcemia in a patient with hyperthyroidism with a high bone turnover state. A 48-year-old postmenopausal woman was diagnosed with hyperthyroidism and osteoporosis and received antithyroid drugs (propylthiouracil 200 mg/day) and denosumab. After 2 months of taking medication, the patient complained of numbness and tingling in the hands and feet and was diagnosed with hypocalcemia (calcium, 5.8 mg/dL; ionized calcium, 0.83 mmol/L). Alfacalcidol (0.5 μg/day) and calcium carbonate (3000 mg/day) were prescribed. Subsequently, the patient's symptoms improved, and her serum calcium level normalized. The risk of denosumab-induced hypocalcemia may be increased in patients with diseases related to high bone turnover, such as hyperthyroidism; therefore, caution is needed.

Risk Analysis of Denosumab-Induced Hypocalcemia in Bone Metastasis Treatment: Renal Dysfunction Is Not a Risk Factor for Its Incidence in a Strict Denosumab Administration Management System with Calcium/Vitamin D Supplementation

We have reported that a strict denosumab administration management system with oral calcium/vitamin D supplementation attenuates denosumab-induced hypocalcemia in 158 cancer patients with bone metastasis. In this report, 27.8% of the patients experienced hypocalcemia, including 0.6% with grade 2. So far, the risk factors for ≥grade 2 hypocalcemia incidence have been identified in denosumab-treated cancer patients, including patients without calcium/vitamin D supplementation. Therefore, the present study aimed to reveal the factors that affect all-grade hypocalcemia incidence with calcium/vitamin D supplementation and team medical care according to the management system. A receiver operating characteristic curve analysis suggested that the cutoff of baseline serum calcium level for all-grade hypocalcemia incidence was 9.3 mg/dL. Multivariate analysis revealed that age ≥65 years (odds ratio, 95% confidence interval: 2.57, 1.11-5.95, p = 0.03), grade 1 or higher serum alkaline phosphatase elevation (3.70, 1.71-8.00, p < 0.01), an adjusted serum calcium level of less than 9.3 mg/dL (3.21. 1.25-8.24, p = 0.02) at baseline, and co-administration of cytotoxic agents (2.33, 1.06-7.11, p = 0.03) are risk factors for the incidence of all-grade hypocalcemia. However, renal dysfunction, which has been suggested to be a risk factor in previous reports, was not a factor. In conclusion, we revealed the risk factors for all-grade hypocalcemia in calcium/vitamin D supplementation and awareness, as demonstrated by the management system. Moreover, renal dysfunction was not a risk factor in our strict denosumab administration management system. Our results support the value of early detection of hypocalcemia incidence to guide the selection of an appropriate management strategy.

Preoperative Low Serum Calcium Levels Predict Poor Prognosis for Patients with Esophageal Cancer

Purpose: Hypercalcemia has been reported as a poor prognostic factor in malignant tumors. However, no report has shown the clinical impact of serum calcium levels on patients with esophageal cancer. We evaluated the prognostic impact of preoperative serum calcium levels on patients with esophageal cancer.

Methods: We evaluated 240 patients (197 men, 43 women; mean age, 66 years; age range, 34–85 years) with esophageal cancer who underwent radical surgery between September 2008 and December 2017. After assigning the patients to two groups (high calcium group, 8.8 mg/dL or more and low calcium group, 8.7 mg/dL or less), we compared the groups’ overall survival and the clinicopathological features. The clinicopathological and prognostic significance of preoperative serum calcium levels were evaluated in a univariate and multivariate analysis.

Results: The patients with deep tumors showed low serum calcium levels significantly more frequently (P <0.05). The low calcium group showed a significantly worse prognosis than the high calcium group (P <0.05). However, low serum calcium level was not an independent poor prognostic factor.

Conclusions: Preoperative low serum calcium levels were associated with advanced tumors. Low serum calcium might be associated with esophageal cancer progression.

Hypocalcemia in a Patient With Metastatic Prostate Cancer From Denosumab Treatment

Denosumab is a humanized monoclonal antibody that binds RANKL to inhibit osteoclast activity. It is indicated for the prevention of skeletal-related events (SRE) in patients with solid tumors who have bone metastasis and in patients with multiple myeloma. Hypocalcemia is one of the known side effects of denosumab, which can be prevented with calcium supplementation.

We present a case of a 72-year-old male with diagnosed metastatic prostate cancer who had received one dose of denosumab 10 days prior to presentation with fatigue, insomnia, and somnolence. His labs showed severe (Grade 4) hypocalcemia, which improved with intravenous calcium supplementation. This case highlights a known but life-threatening side effect of denosumab and the potential need for prolonged calcium monitoring in patients placed on the drug.

[Pharmaceutical Intervention According to Strict Management System Can Normalize Decreased Serum Calcium Level by Denosumab and Prevent Its Aggravation]

Denosumab is a fully monoclonal antibody against the receptor activator of nuclear factor kappa-B ligand (RANKL), and prevents skeletal-related events by bone metastasis. Hypocalcemia is the most typical adverse effect of denosumab use. We have developed a management system for the more efficient and safer management of denosumab administration, and evaluated pharmaceutical interventions for the better control of hypocalcemia. All pharmaceutical interventions in the system from April 2016 to March 2020 were retrospectively evaluated. We have also assessed the incidence of hypocalcemia in 158 patients who were administered denosumab for six months or more in the period. A total of 282 pharmaceutical interventions (7.0% of the total administration) were conducted. The most conducted intervention was regarding hypocalcemia, which involved the suspension of the injection and/or the increase of calcium and vitamin D supplement with 65% adoption and 17% temporary treatment suspensions. Other interventions were about hypercalcemia, request of laboratory examination and ordering supplements, dental consultation, and poor renal function. A total of 199 interventions (70.6%) were adopted, with 33 administrations suspended. The frequency of hypocalcemia was 27.8% with just one patient having grade 2 hypocalcemia, suggesting that there were no severe cases. Moreover, hypocalcemia was significantly normalized following pharmaceutical intervention and/or handling by physicians (p=0.02) according to the system. Conversely, the normalization rate in hypercalcemia did not differ according to the countermeasures. In conclusion, pharmaceutical interventions according to our management system benefit safe denosumab treatment, especially in severe hypocalcemia prevention.

Hypocalcaemia following denosumab in prostate cancer: A clinical review

OBJECTIVES

Denosumab is often used in men with advanced prostate cancer to prevent skeletal-related events, but can be associated with severe hypocalcaemia. Our objective was to review the pathophysiology, identify risk factors and provide recommendations for prevention and management of denosumab-associated hypocalcaemia.

DESIGN

We reviewed the literature regarding denosumab-associated severe hypocalcaemia, defined as necessitating hospitalization for intravenous calcium treatment, in the context of prostate cancer.

PATIENTS

Men with prostate cancer with severe denosumab-associated hypocalcemia.

RESULTS

We identified 20 men with prostate cancer with severe denosumab-associated hypocalcemia, including the present case. Median age (range) was 70 years (45-86). All had skeletal metastases and presented with symptomatic hypocalcemia 16 days (4-35) after the initial (n = 18) or second (n = 2) denosumab treatment, with a serum total calcium of 1.36 mmol/L (1.13-1.91). The key risk factor was presence of active osteoblastic metastases, evidenced by elevated serum alkaline phosphatase, 838 U/L (58-2620) and supportive imaging. Other risk factors reported in some men included vitamin D deficiency (<50 nmol/L), 25-OH vitamin D 44 nmol/L (22-81), renal impairment, serum creatinine 103 μmol/L (62-1131) and hypomagnesaemia, 0.82 mmol/L (0.29-1.20). Men received intravenous calcium infusions for 16 days (1-90), and median total intravenous elemental calcium requirements were 3.17 g (0.47-26.65).

CONCLUSIONS

Denosumab treatment in men with metastatic prostate cancer can be associated with life-threatening hypocalcaemia requiring prolonged hospitalization for intravenous calcium treatment. Modifiable risk factors should be corrected before denosumab administration. In men with active osteoblastic metastases, consideration should be given to delay denosumab treatment until underlying disease activity is controlled, and/or be administered with close monitoring and proactive treatment with calcium and calcitriol.

Denosumab-induced hypocalcemia in patients with osteoporosis: can you know who will get low?

Hypocalcemia was reported at low rates (0.05-1.7%) in denosumab-treated postmenopausal women with osteoporosis. This real-life study shows a 7.4% rate of denosumab-induced hypocalcemia in community-dwelling osteoporotic men and women. Pretreatment serum calcium and creatinine levels are major predictors for this complication. Serum-calcium monitoring may help to identify and prevent severe hypocalcemia.

PURPOSE

RCTs have reported a 0.05-1.7% rate of hypocalcemia in denosumab-treated postmenopausal women with osteoporosis, but long-term real-life data are lacking. We assessed the rate of hypocalcemia in osteoporotic community-dwelling patients treated with denosumab.

METHODS

A retrospective analysis was conducted based on medical records (2010-2018) from a large HMO. An albumin-adjusted serum calcium concentration lower than 8.5 mg/dL was defined as hypocalcemia.

RESULTS

We included 2005 patients (93% women, mean age 76 ± 9 years). Hypocalcemia developed during treatment in 149 patients (7.4%; 1% less than 8 mg/dL): in 66 after 0.5-1 years; 48 after 1-2 years; 35 after > 2 years. On comparison of the hypocalcemic and normocalcemic patients, the strongest predictors of hypocalcemia were pretreatment levels of albumin-adjusted serum calcium (9.1 ± 0.4 vs. 9.4 ± 0.5 mg/dL, respectively; p < 0.05) and creatinine (0.9 ± 0.5 vs. 0.8 ± 0.3 mg/dL, respectively; p < 0.05). The hypocalcemia rate increased in parallel to a decrease in eGFR (p = 0.032 for the difference between eGFR ranges). Baseline calcium level ≤ 9.31 mg/dL predicted hypocalcemia with a sensitivity of 77% and specificity of 56%. A model of (- 2)*calcium + creatinine predicted hypocalcemia (3.7% when lower and 17.1% when higher than - 17.4). Gender, age, 25-hydroxyvitamin-D, parathyroid hormone, alkaline phosphatase, and whether denosumab was given as first or advanced line of osteoporotic therapy had no predictive value.

CONCLUSION

Real-life rates of denosumab-induced hypocalcemia are higher than previously reported. Hypocalcemia might develop after each dose of denosumab in ongoing treatment. Adequate calcium and vitamin D supplementation are needed. Serum calcium monitoring is advised in high-risk patients for early detection of severe hypocalcemia.

Denosumab for dialysis patients with osteoporosis: A cohort study

Evidence for the efficacy of denosumab in HD patients is limited. Accordingly, here we report a study on the safety and efficacy of denosumab in these patients. We prospectively followed 324 patients (121 HD and 203 non-HD patients) receiving denosumab between June 2013 and May 2018, assessing changes in bone mineral density (BMD) and bone metabolic markers, and noting side-effects. Annual changes in BMD at the lumbar spine in HD and non-HD patients from baseline were, respectively, 6.7 ± 11.1% and 7.5 ± 10.2% (p = 0.60), those at the femoral neck were 4.3 ± 7.9% and 3.1 ± 9.5% (p = 0.32), and those at the distal radius were −0.5 ± 6.4% and 0.2 ± 13.0% (p = 0.66). The prevalence of hypocalcemia (<8.5 mg/dL) was significantly higher in HD than in non-HD patients (35.6% vs 5.4%, p < 0.001). The median elapsed time between the first injection of denosumab and the occurrence of hypocalcemia was 7 days in HD patients. The decrease of serum calcium was greater in patients with higher TRACP5b, corticosteroid use, and those without CaCO₃ supplementation. Our study suggests that denosumab was equally as effective in HD as non-HD patients. However, careful hypocalcemia monitoring, for at least 4 weeks, is recommended for HD patients.

Hypocalcemia in cancer patients: An exploratory study

Introduction

Calcium has several physiological functions and when it registers abnormal serum levels those functions may be impacted with potentially severe consequences. There is much research on hypercalcemia in cancer patients, but there are no recent studies on the prevalence of hypocalcemia in those patients. However, there has been an evolution in oncology, namely, new drugs that may directly or indirectly result in hypocalcemia. The primary aim was to explore the association of hypocalcemia with the diverse types of cancer. The secondary aim was to study the influence that hypocalcemia might have on survival.

Methods

Review of the records of patients ≥18 years old, with total calcium <2.0 mmol/L measured in 2013 in a cancer center.

Results

Eight hundred twenty-nine patients were included. Four hundred thirty-nine (53%) were male. The median age was 63 years. The most frequent cancer diagnoses were hematological 196 (24%) and colorectal 111 (13%). Six hundred thirty-eight patients had measured serum albumin, with a median of 25.5 g/L (14-47). When corrected for albumin level, calcium was in the normal range in 210 (33%) cases. The median survival of patients with corrected calcium lower than normal was 479 days (95% confidence interval [CI]: 309-649) and that of patients with normal corrected calcium was 62 days (95% CI: 33-91), P < .001. In a multivariate analysis, age, primary cancer, and albumin were significantly associated with survival.

Conclusion

Hypocalcemia is associated with several types of cancer. A low calcium level is not by itself a factor of a poor prognosis since other factors seem to be more important.

Evaluating the impact of regulatory action on denosumab-induced hypocalcaemia in Japan

WHAT IS KNOWN AND OBJECTIVE

Since its introduction in April 2012, denosumab has been administered to approximately 7,300 patients as of August 2012, and 32 cases of serious hypocalcaemia after denosumab administration, including two deaths, have been reported in Japan. A Dear Healthcare Professional Letter of Rapid Safety Communication ('Blue letter') was released to warn about the risks of hypocalcaemia associated with denosumab. The goal of this study therefore was to measure the impact of regulatory action on denosumab-induced hypocalcaemia in Japan by using an electronic medical information database (MID).

METHODS

We used two different aggregated data sets based on MIDs (data sets one and two). The patients studied were those who were newly prescribed denosumab or zoledronic acid between April 2012 and September 2014. We assessed four indicators: (a) the proportion of patients with calcium supplementation at the initial denosumab treatment, (b) the proportion of patients who underwent a serum calcium test, (c) the average number of serum calcium tests performed and (d) the prevalence of hypocalcaemia. All indices were aggregated by every 3 months. To evaluate the impact of regulatory action, we used difference in difference (DID) analysis.

RESULTS AND DISCUSSION

The proportion of patients with calcium supplementation at the initial denosumab treatment increased year by year in both data sets. The average number of serum calcium tests increased year by year in data set two. There was a significant difference in the prevalence of hypocalcaemia in data set two. This suggests that the estimate of impact of the regulatory action may vary according to the database. In DID analysis, however, significant influences of the regulatory action on combination use with a calcium supplement were detected in both data sets.

WHAT IS NEW AND CONCLUSION

There was a significant influence on combination use of denosumab with vitamin D and/or calcium supplement in both data sets. That there was no apparent increase in the prevalence of denosumab-induced hypocalcaemia, suggests that the regulatory action had an impact in the clinical setting studied. Such regulatory actions may play an important role in the promotion of drug safety.

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.

Hypocalcemia after Denosumab in a Pulmonary Hypertension Patient Receiving Epoprostenol

We report the case of a 50-year-old woman with anorexigen-induced pulmonary arterial hypertension treated with epoprostenol, who presented with Trousseau's sign, leading to the diagnosis of severe hypocalcemia for which substitution was started (initially orally, followed by intravenous substitution). After further analysis, we assume that epoprostenol-induced diarrhea caused malabsorption (as other reasons were excluded), leading to nutritional osteomalacia with secondary hyperparathyroidism. We discovered that even more severe hypocalcemia was induced by the treatment with the anti-osteoporotic drug denosumab, which was started after the diagnosis of osteoporosis on bone densitometry. In our opinion, clinicians have to be aware that in patients with malabsorption, antiresorptive therapy can induce dangerous and even life-threatening hypocalcemia, even in patients with normal renal function.

Denosumab: Current Use in the Treatment of Primary Bone Tumors

Denosumab, a human monoclonal antibody that inhibits bone resorption by binding on the receptor activator of the nuclear factor kappa-β ligand, has recently emerged as an additional option in the treatment of musculoskeletal osteolytic tumors. This article focuses on the recent literature regarding the effectiveness of denosumab in the management of giant cell tumor, multiple myeloma, aneurysmal bone cyst, and osteosarcoma. The mechanism of action of denosumab in the management of these tumors and the associated side effects are discussed in detail. [ Orthopedics. 2017; 40(4):204-210.].

High bone turnover elevates the risk of denosumab-induced hypocalcemia in women with postmenopausal osteoporosis

Hypocalcemia is the most common major adverse event in patients with osteoporosis receiving the bone resorption inhibitor denosumab; however, limited information is available regarding risk factors of hypocalcemia. Therefore, this study aimed to identify the risk factors of hypocalcemia induced by denosumab treatment for osteoporosis. We retrospectively reviewed the records of patients who had received initial denosumab supplemented with activated vitamin D for osteoporosis. Serum levels of the following bone turnover markers (BTMs) were measured at baseline: bone-specific alkaline phosphatase (BAP), total N-terminal propeptide of type 1 procollagen (P1NP), tartrate-resistant acid phosphatase 5b (TRACP-5b), and urinary cross-linked N-telopeptide of type 1 collagen (NTX). Of the 85 denosumab-treated patients with osteoporosis studied, 22 (25.9%) developed hypocalcemia. Baseline serum total P1NP, TRACP-5b, and urinary NTX were significantly higher in patients with hypocalcemia than in those with normocalcemia following denosumab administration (all P<0.01). Multivariate logistic regression analysis revealed that patients with total P1NP >76.5 μg/L, TRACP-5b >474 mU/dL, or urinary NTX >49.5 nmol bone collagen equivalent/mmol creatinine had a higher risk of hypocalcemia (P<0.01). Our study suggests that denosumab may have a greater impact on serum calcium levels in patients with postmenopausal osteoporosis with higher baseline bone turnover than in patients with postmenopausal osteoporosis with normal baseline bone turnover, because maintenance of normal serum calcium in this subgroup is more dependent on bone resorption. Close monitoring of serum calcium levels is strongly recommended for denosumab-treated patients with high bone turnover, despite supplementation with activated vitamin D and oral calcium.

Incidence of hypocalcemia in patients receiving denosumab for prevention of skeletal-related events in bone metastasis

Background

Denosumab therapy is commonly used for the prevention of skeletal-related events in patients with bone metastasis. However, a common side effect of denosumab is hypocalcemia.

Objective

The aim of the study is to determine the incidence of hypocalcemia in patients receiving denosumab for prevention of skeletal-related events in bone metastasis and evaluate risk factors for developing hypocalcemia.

Methods

This was a retrospective medication use evaluation reviewing the incidence of hypocalcemia in patients receiving outpatient denosumab for prevention of skeletal-related events at Yale–New Haven Hospital. Additionally, various risk factors were reviewed to determine their risk of developing hypocalcemia.

Results

As per Common Terminology Criteria for Adverse Events v4.03, of the 106 patients included in the study population, 37 (35%) patients had an incidence of hypocalcemia within 30 days of denosumab administration. Fourteen patients (13.2%) had an incidence of grade 1, 13 patients (12.3%) had an incidence of grade 2 hypocalcemia, and 7 patients (6.6%) had an incidence of grade 3 hypocalcemia. Grade 4 hypocalcemia occurred in three (2.8%) patients. Calcium supplementation did not decrease the risk of developing hypocalcemia. Patients who had one or more episodes of acute kidney insufficiency were at a higher risk of developing hypocalcemia (odds ratio = 7.5 (95% confidence interval = 1.8–36.3), p = 0.001).

Conclusion

This study found that the overall incidence of hypocalcemia and severe hypocalcemia was higher than reported in clinical trials. Additionally, calcium supplementation did not have an effect on incidence of hypocalcemia, while patients who experienced acute kidney insufficiency while on denosumab had a higher likelihood of developing hypocalcemia.

Side effects of bone-targeted therapies in advanced breast cancer

In up to 75% of cases, advanced breast cancer patients eventually develop bone metastases with often debilitating skeletal-related events (SREs). Osteoclast inhibitors are commonly used as therapeutic mainstay with clinical studies showing superiority of denosumab over bisphosphonates (e.g., zoledronate) for the prevention of SREs. The present review discusses the adverse event profile of these agents, and addresses the prevention and management of untoward side effects. Adverse events associated with osteoclast inhibitors comprise osteonecrosis of the jaw and hypocalcemia. Hypocalcemia is more common with denosumab, particularly in severe renal dysfunction. During therapy, the appropriate prevention of these adverse events includes close attention to dental health, avoidance of invasive dental procedures, supplementation with calcium and vitamin D unless patients are hypercalcemic, and regular monitoring of relevant serum values. Relating to the risk of nephrotoxicity, bisphosphonates but not denosumab have been incriminated. Therefore, serum creatinine levels should be checked prior to each dose of zoledronate, and in severe renal dysfunction (creatinine clearance < 30 ml/min) zoledronate is contraindicated anyway. Acute-phase reactions are particularly linked to bisphosphonates. Consequently, if these adverse events predominate, switching to denosumab is recommended.

Time Course of Calcium Concentrations and Risk Factors for Hypocalcemia in Patients Receiving Denosumab for the Treatment of Bone Metastases From Cancer

BACKGROUND

Severe hypocalcemia sometimes develops during denosumab treatment for bone metastases from cancer and is, therefore, an important issue. However, limited information is available on the risk factors for hypocalcemia and the appropriate interval for monitoring serum calcium concentration.

OBJECTIVE

The present study aimed to identify the risk factors for grade ≥2 hypocalcemia and to investigate the time course of serum calcium concentrations in patients receiving denosumab for bone metastases from cancer.

METHOD

The medical records of 66 cancer patients treated with denosumab between April 2012 and August 2013 were retrospectively reviewed.

RESULT

Of the 66 enrolled patients, 11, 5, and 1 developed grade 1, 2, and 3 hypocalcemia, respectively. All 4 patients with a baseline estimated glomerular filtration rate (eGFR) of <30 mL/min developed hypocalcemia. Hypocalcemia occurred in only 20%, 24%, and 15% of patients with an eGFR of 30 to 59, 60 to 89, and ≥90 mL/min, respectively. Multivariate logistic regression analysis revealed that lower eGFR values (odds ratio, 1.72 per 10 mL/min decrease, P = 0.02) were significantly associated with grade ≥2 hypocalcemia. In 11 patients who developed hypocalcemia during the first treatment course, the mean calcium concentrations decreased from 9.8 mg/dL at baseline to 8.4 mg/dL during the first week and reached a nadir of 8.1 mg/dL during the second week.

CONCLUSION

Our results support more frequent monitoring of serum calcium concentrations at baseline and during the first 2 weeks of treatment in patients receiving denosumab, especially those with an eGFR <30 mL/min.