Hypocalcemia Risk of Denosumab Across the Spectrum of Kidney Disease: A Population-Based Cohort Study

Efficacy and Safety of Denosumab vs Zoledronic Acid in OI Adults: A Prospective, Open-Label, Randomized Study

CONTEXT

The comparative effectiveness of denosumab and zoledronic acid for adult patients with osteogenesis imperfecta (OI) has not been established.

OBJECTIVE

To evaluate the efficacy and safety of denosumab and zoledronic acid in adult patients with OI.

METHODS

This was a prospective, open-label study. Patients were randomized to receive denosumab 60 mg every 6 months or zoledronic acid 5 mg once for 12 months. Pathogenic mutations of OI were identified by next-generation sequencing and confirmed by Sanger sequencing. Percentage changes in the areal bone mineral density (aBMD), trabecular bone score (TBS), and bone turnover biomarkers (BTMs) from baseline to 6 and 12 months of treatment, as well as safety, were evaluated.

RESULTS

A total of 51 adults with OI (denosumab: 25, zoledronic acid: 26) were included, of whom 49 patients had identified pathogenic mutations. At 12 months, aBMD at the lumbar spine and total hip significantly increased by 4.34% (P = .005) and 1.45% (P = .023) in the denosumab group and by 4.92% (P = .006) and 2.02% (P = .016) in the zoledronic acid group, respectively. TBS showed an increasing trend by 1.39% and 2.70% in denosumab and zoledronic acid groups, respectively. Serum levels of β-isomerized carboxy-telopeptide of type I collagen and alkaline phosphatase markedly decreased after denosumab treatment. Percentage changes in aBMD, TBS, and BTMs during the treatment were similar between the 2 groups. Patients with OI with milder phenotypes showed a significantly higher increase in the TBS after 12 months of denosumab treatment than those with more severe phenotypes (P = .030). During the study period, the denosumab group had fewer adverse events than the zoledronic acid group.

CONCLUSION

Denosumab effectively increases aBMD in adults with OI, with similar efficacy to zoledronic acid. Long-term and large-sample studies are needed to confirm the antifracture efficacy and safety of denosumab in adult patients with OI.

Increased risk of hypocalcemia with decreased kidney function in patients prescribed bisphosphonates based on real-world data from the MID-NET® in Japan: a new-user cohort study

BACKGROUND

In the post-marketing stage, cases of hypocalcemia associated with bisphosphonate preparations (BPs) have been reported in patients with decreased kidney function, despite warning against use of BPs in such patients in the package insert (PI) of Japan. The purpose of this study was to investigate the safety of BPs in patients with decreased kidney function.

METHODS

The cohort study was conducted in patients with osteoporosis and newly prescribed bisphosphonate utilizing real-world data from MID-NET® in Japan. The adjusted hazard ratios (aHRs) for hypocalcemia (a corrected serum Ca level < 8.00 mg/dL) relative to the normal group were calculated in each decreased kidney function group (mild, moderate or severe group).

RESULTS

A total of 14,551 patients were included in the analysis, comprising 2,601 (17.88%) with normal (eGFR ≥ 90 mL/min/1.73m2), 7,613 (52.32%) with mild (60 ≤ eGFR < 90 mL/min/1.73m2), 3,919 (26.93%) with moderate (30 ≤ eGFR < 60 mL/min/1.73m2), and 418 (2.87%) with severe kidney function (eGFR < 30 mL/min/1.73m2). The aHRs (95% confidence interval) for hypocalcemia were 1.85 (0.75-4.57), 2.30 (0.86-6.21), and 22.74 (8.37-61.78) in the mild, moderate, and severe groups, respectively. The increased risk of hypocalcemia depending on kidney function was also observed even when calculating the aHR for each specific BP such as alendronate sodium hydrate, minodronic acid hydrate, and sodium risedronate hydrate. Furthermore, similar results were obtained in the sensitivity analysis by altering the outcome definition to a 20% or more reduction in corrected serum Ca level from the baseline, as well as when focusing on patients with more than one laboratory test result per 30 days during the follow-up period.

CONCLUSIONS

These findings suggest that the risk of hypocalcemia during BP prescription is higher in patients with decreased kidney function, particularly those with severely decreased kidney function. The quantitative real-world evidence on the safety risk of BPs obtained in this study has led to the PI revision describing a relationship between hypocalcemia risk and decreased kidney function as a regulatory action in Japan and will contribute to promoting the proper use of BPs with appropriate risk management in clinical practice.

Recommended calcium intake in adults and children with chronic kidney disease-a European consensus statement

Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to controlling hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN), developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. The main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/day and not exceeding 1500 mg/day to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.

Reducing the risk of denosumab-induced hypocalcemia in patients with advanced chronic kidney disease: a quality improvement initiative

Denosumab can improve bone health in advanced kidney disease (CKD) but is associated with hypocalcemia. We created a clinical care pathway focused on the safe provision of denosumab in advanced CKD that reduced the risk of hypocalcemia by 37% at our hospital. Similar pathways could be adopted and tested in other centers.

PURPOSE

There is an increased risk of hypocalcemia with denosumab in advanced chronic kidney disease (CKD). We aimed to reduce the proportion of patients with advanced CKD who experienced denosumab-induced hypocalcemia at our center.

METHODS

We conducted a quality improvement (QI) project of patients with CKD stage 3b or less (i.e., estimated glomerular filtration rate <45 mL/min/1.73m2 including dialysis) who were part of the Osteoporosis and Bone Disease Program at St. Joseph's Health Care London (Canada) between December 2020 and January 2023. Our intervention was a clinical care pathway which optimized CKD mineral and bone disorder (CKD-MBD) and 25-hydroxyvitamin levels; provided calcium and vitamin D prophylaxis; promoted multidisciplinary communication between bone and kidney specialists; and carefully monitored calcium post-denosumab injection. Our primary outcome measure was the proportion of patients with hypocalcemia (defined by albumin-corrected serum calcium <1.9mmol/L) at 60 days. Process measures included the appropriate provision of calcium and vitamin D prophylaxis. Balance measures included the development of hypercalcemia and hyperphosphatemia following prophylaxis. We used plan-do-see-act cycles to study four tests of change and presented results using descriptive statistics and run charts.

RESULTS

There were 6 patients with advanced CKD treated with denosumab prior to the implementation of our care pathway (March 2015-October 2020; 83% receiving dialysis). At the time of their denosumab injection, 83% were using 500-1000 mg of calcium, and 83% used 1000-2000 IU of vitamin D3. Fifty percent developed denosumab-induced hypocalcemia. Following the implementation of our care pathway, 15 patients (40% receiving dialysis) were treated with denosumab. Ninety-three percent received calcium at a daily dose of 350 to 2250 mg and 87% received 1000-2000 IU of vitamin D3. Thirteen percent developed denosumab-induced hypocalcemia. There was no hypercalcemia or hyperphosphatemia.

CONCLUSIONS

A clinical care pathway focused on the safe provision of denosumab in advanced CKD reduced the risk of hypocalcemia in patients treated in our hospital. Similar pathways could be adopted and tested in other centers.