Development of Risk Prediction Model for Grade 2 or Higher Hypocalcemia in Bone Metastasis Patients Treated with Denosumab plus Cholecalciferol (Vitamin D3)/Ca Supplement

Denosumab-induced hypocalcemia is sometimes severe, and although a natural vitamin D/Ca combination is used to prevent hypocalcemia, some patients rapidly develop severe hypocalcemia even under supplementation. It is clinically important to predict this risk. This study aimed to develop a risk prediction model for grade 2 or higher hypocalcemia within 28 days after the first denosumab dose under natural vitamin D/Ca supplementation. Using a large database containing multicenter practice data, 2,399 bone metastasis patients who were treated with denosumab between June 2013 and May 2020 were retrospectively analyzed. Background factors in patients who developed grade 2 or higher hypocalcemia within 28 days after the first denosumab dose and those who did not were compared by univariate analysis. Multivariate analysis was conducted to develop a risk prediction model. The model was evaluated for discriminant performance (ROC-AUC: receiver operating characteristic - area under the curve, sensitivity, specificity) and predictive performance (calibration slope). A total of 124 patients in the hypocalcemia group and 1,191 patients in the non-hypocalcemia group were extracted. A risk prediction model consisting of sex, Ca, albumin, alkaline phosphatase, osteoporosis, breast cancer, gastric cancer, proton pump inhibitor combination, and pretreatment with zoledronic acid was developed. The ROC-AUC was 0.87. Sensitivity and specificity were 83% and 81%, respectively, and the calibration slope indicated acceptable agreement between observed and predicted risk. This model appears to be useful to predict the risk of denosumab-induced hypocalcemia and thus should be helpful for risk management of denosumab treatment in patients with bone metastases. This article is protected by copyright. All rights reserved.

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.

[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.

Predictors for development of denosumab-induced hypocalcaemia in cancer patients with bone metastases determined by ordered logistic regression analysis

This retrospective study was undertaken to identify predictors for the development of hypocalcaemia even with prophylactic administration of calcium and vitamin D, and to help guide future strategies to improve the safety, efficacy, and QOL of patients receiving denosumab. Between January 2016 and February 2020, a total of 327 advanced cancer patients at our hospital who were receiving denosumab were enrolled. Variables associated with the development of hypocalcaemia were extracted from the clinical records. The level of hypocalcaemia was evaluated using CTCAE version 5. Multivariate ordered logistic regression analysis was performed to identify predictors for the development of hypocalcaemia. Optimal cut off thresholds were determined using ROC analysis. Values of P < 0.05 (2-tailed) were considered significant. 54 patients have developed hypocalcemia (≥ Grade 1). Significant factors identified included concomitant use of vonoprazan [odds ratio (OR) = 3.74, 95% confidence interval (CI) 1.14–12.26; P = 0.030], dexamethasone (OR = 2.45, 95%CI 1.14–5.42; P = 0.022), pre-treatment levels of serum calcium (OR = 0.27, 95%CI 0.13–0.54; P < 0.001), ALP/100 (OR = 1.04, 95%CI 1.01–1.07; P = 0.003), and haemoglobin (OR = 0.79, 95%CI 0.68–0.93; P = 0.004). ROC curve analysis revealed that the threshold for pre-treatment levels of serum calcium was ≤ 9.3 mg/dL, ALP was ≥ 457 U/L, and haemoglobin was ≤ 10.4 g/dL. In conclusion, concomitant use of vonoprazan or dexamethasone, and pre-treatment levels of serum calcium (low), ALP (high) and haemoglobin (low) were identified as significant predictors for the development of denosumab-induced hypocalcaemia.

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.

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.

Creation of a Multicenter Pediatric Inpatient Data Repository Derived from Electronic Health Records

BACKGROUND

Integration of electronic health records (EHRs) data across sites and access to that data remain limited.

OBJECTIVE

We developed an EHR-based pediatric inpatient repository using nine U.S. centers from the National Institute of Child Health and Human Development Pediatric Trials Network.

METHODS

A data model encompassing 147 mandatory and 99 optional elements was developed to provide an EHR data extract of all inpatient encounters from patients <17 years of age discharged between January 6, 2013 and June 30, 2017. Sites received instructions on extractions, transformation, testing, and transmission to the coordinating center.

RESULTS

We generated 177 staging reports to process all nine sites' 147 mandatory and 99 optional data elements to the repository. Based on 520 prespecified criteria, all sites achieved 0% errors and <2% warnings. The repository includes 386,159 inpatient encounters from 264,709 children to support study design and conduct of future trials in children.

CONCLUSION

Our EHR-based data repository of pediatric inpatient encounters utilized a customized data model heavily influenced by the PCORnet format, site-based data mapping, a comprehensive set of data testing rules, and an iterative process of data submission. The common data model, site-based extraction, and technical expertise were key to our success. Data from this repository will be used in support of Pediatric Trials Network studies and the labeling of drugs and devices for children.