Real-World Safety and Effectiveness of Denosumab in Patients with Osteoporosis: A Prospective, Observational Study in South Korea

Denosumab and the Risk of Diabetes in Patients Treated for Osteoporosis

Importance

Denosumab, a humanized monoclonal antibody against receptor activator of nuclear factor κB ligand (RANKL), is a widely used antiresorptive medication for osteoporosis treatment. Recent preclinical studies indicate that inhibition of RANKL signaling improves insulin sensitivity, glucose tolerance, and β-cell proliferation, suggesting that denosumab may improve glucose homeostasis; however, whether denosumab reduces the risk of incident diabetes remains unclear.

Objective

To evaluate whether denosumab use is associated with a lower risk of developing diabetes in patients with osteoporosis.

Design, Setting, and Participants

This nationwide, propensity score-matched cohort study used administrative data from Taiwan's National Health Insurance Research Database. Adult patients who received denosumab for osteoporosis therapy in Taiwan between 2012 and 2019 were included. To eliminate the inherent bias from confounding by indication, the patients were categorized into a treatment group (34 255 patients who initiated denosumab treatment and adhered to it) and a comparison group (34 255 patients who initiated denosumab treatment but discontinued it after the initial dose) according to the administration status of the second dose of denosumab. Propensity score matching was performed to balance patient characteristics and to control for confounders.

Exposure

Treatment with denosumab.

Main Outcomes and Measures

The primary outcome was incident diabetes requiring treatment with antidiabetic drugs. A Cox proportional hazards model was used to estimate the hazard ratio (HR) for incident diabetes. Data were analyzed from January 1 to November 30, 2023.

Results

After propensity score matching, 68 510 patients were included (mean [SD] age, 77.7 [9.8] years; 57 762 [84.3%] female). During a mean (SD) follow-up of 1.9 (1.6) years, 2016 patients developed diabetes in the treatment group and 3220 developed diabetes in the comparison group (incidence rate, 35.9 vs 43.6 per 1000 person-years). Compared with the comparison group, denosumab treatment was associated with a lower risk of incident diabetes (HR, 0.84; 95% CI, 0.78-0.90). Several sensitivity analyses also demonstrated similar results of lower diabetes risk associated with denosumab treatment.

Conclusions and relevance

The results from this cohort study indicating that denosumab treatment was associated with lower risk of incident diabetes may help physicians choose an appropriate antiosteoporosis medication for patients with osteoporosis while also considering the risk of diabetes.

Cost-consequence analysis of continuous denosumab therapy for osteoporosis treatment in South Korea

BACKGROUND

Insurance reimbursement provisions in South Korea limit osteoporosis medication availability for patients with T-scores exceeding - 2.5. This study aimed to evaluate the financial impact and fracture prevention of continuous denosumab therapy until a T-score>-2.0 (Dmab-C strategy), versus discontinuation of denosumab after reaching T-score>-2.5 (Dmab-D strategy) in osteoporosis patients.

METHODS

A cost-consequence analysis from a Korean healthcare system perspective was performed using a newly developed Markov model. The incidence of vertebral and non-vertebral fracture, fracture-related deaths, drug costs, and fracture-treatment costs were estimated and compared between Dmab-C and Dmab-D strategy over a lifetime in eligible patients aged 55 years.

RESULTS

Base-case analysis revealed that Dmab-C prevented 32.21 vertebral fracture (VF) and 12.43 non-VF events per 100 patients over a lifetime, while reducing 1.29 fracture-related deaths. Lifetime direct healthcare cost saving per patient was KRW 1,354,655 if Dmab-C replaces Dmab-D. When productivity losses were considered, Dmab-C saved KRW 29,025,949 per patient compared to Dmab-D. The additional treatment costs of Dmab-C could be offset by the higher subsequent treatment costs and fracture treatment costs of Dmab-D. The sensitivity analysis showed consistent patterns with results of the base-case analysis.

CONCLUSION

Continuous treatment using denosumab until osteoporosis patients achieve and maintain a T-score of -2.0 would provide greater clinical and economic benefits in terms of fracture prevention and reduced mortality risks compared to outcomes from discontinuing treatment at a T-score of -2.5 or above. This new treatment strategy would effectively lower the risk of fractures and fracture-related mortality, ultimately leading to lower medical expenses.

Prevalence of denosumab-induced hypocalcemia: a retrospective observational study of patients routinely monitored with ionized calcium post-injection

We assessed the prevalence of hypocalcemia after denosumab injections in a real-world cohort routinely monitored for calcium during up to 7.5 years of treatment. Among 1096 injections in 242 patients, 6.3% resulted in hypocalcemia, and was independent of the injection number. Severe hypocalcemia was rare (1%).

PURPOSE

To assess the prevalence of and risk factors for hypocalcemia after administration of denosumab in a patient cohort routinely monitored for ionized calcium after each dose.

METHODS

In this retrospective observational study, we analyzed denosumab-induced hypocalcemia in a real-world cohort who were routinely followed up with ionized calcium pre- and post-injection (within 31 days after injection) during the period 2011 to 2020.

RESULTS

In total, we included data from 1096 denosumab injections in 242 individuals (1-15 injections per patient). The mean age for the first injection was 74 ± 10 years, and 88% were female. Post-injection hypocalcemia occurred after 6.3% of all injections (4.6% mild, 0.6% moderate, and 1.1% severe) and was independent of the number of injections (rate of hypocalcemia varied from 3-8%). Risk factors for hypocalcemia were male sex, severe renal failure, pre-injection hypocalcemia, hypomagnesemia, hypophosphatemia, and vitamin D insufficiency. Furthermore, older age was not associated with an increased hypocalcemia risk.

CONCLUSIONS

Denosumab-induced hypocalcemia is a prevalent adverse event, which occurs independently of the number of injections. However, severe hypocalcemia is a rare occurrence, and severe renal failure and nutritional status appear to be important predictive factors. Magnesium and phosphate might add value in the pre-injection risk assessment; however, this observation needs to be confirmed in larger cohorts.

Effect of Denosumab on Bone Density in Postmenopausal Osteoporosis: A Comparison with and without Calcium Supplementation in Patients on Standard Diets in Korea

The side effects and safety issues tied to calcium supplementation raise questions about its necessity in osteoporosis treatment. We retrospectively evaluated 189 postmenopausal osteoporosis patients treated with denosumab for 12 months. Patients exhibited neither renal dysfunction nor compromised general dietary intake. Patients were divided into three groups as follows: group A, weekly vitamin D 7000 IU; group B, daily vitamin D 1000 IU with elemental calcium 100 mg; and group C, daily vitamin D 1000 IU with elemental calcium 500 mg. All groups showed significant increases in bone density: +6.4 ± 4.7% for the lumbar spine, +2.2 ± 3.5% for the femoral neck, and +2.4 ± 3.8% for the total hip in group A; +7.0 ± 10.9% for the lumbar spine, +2.3 ± 5.2% for the femoral neck, and +2.4 ± 3.8% for the total hip in group B; and + 6.7 ± 8.7% for the lumbar spine, +2.5 ± 8.4% for the femoral neck, and +2.3 ± 4.0% for the total hip in group C. Serum calcium levels increased over time in all three groups with no significant difference. Changes in CTX and P1NP levels did not differ between the groups (all p > 0.05). With regular dietary intake, calcium supplementation levels showed no significant effect on bone density, bone marker changes, or hypocalcemia incidence during denosumab treatment.

Adverse Effects of Denosumab in Kidney Transplant Recipients: A 20-Year Retrospective Single-Center Observation Study in Central Taiwan

BACKGROUND

Bone loss can be noted in kidney transplantation recipients (KTRs) and can be related to fracture events. Denosumab, a potent monoclonal antibody to RANK ligand, increases lumbar bone mineral density. However, safety data for denosumab remain limited regarding transplant recipients. Hypocalcemia and increased genital tract infections have been mentioned as adverse effects in KTRs after being prescribed denosumab.

METHODS

We retrospectively analyzed the electronic medical records of KTRs during the recent 20 years who had been prescribed antiresorptive therapy and were >18 years old. Medical records and their clinical data were reviewed and analyzed. We compared the frequency of adverse effects between denosumab with other antiresorptive therapies.

RESULTS

A total of 70 KTRs were enrolled, with 46 patients being given denosumab and the first injection being noted on October 31, 2014. No significant differences were seen in mortality rate, opportunistic infection, pneumonia, or genitourinary tract infection. One diagnosis of osteonecrosis of the jaw was noted in the denosumab group (2.2%). A higher incidence of hypocalcemia (<8.4 mg/dL) was noted in the denosumab group (34.8%), and a higher but nonsignificant difference in the incidence of severe hypocalcemia was also noted in the group.

CONCLUSIONS

Denosumab may be considered as safe as other antiresorptive therapies for KTRs. However, more hypocalcemia events have been noted, so medical personnel may need to be cautious when prescribing its use.

Persistence with Denosumab in Male Osteoporosis Patients: A Real-World, Non-Interventional Multicenter Study

BACKGRUOUND

Persistence with denosumab in male patients has not been adequately investigated, although poor denosumab persistence is associated with a significant risk of rebound vertebral fractures.

METHODS

We retrospectively evaluated 294 Korean male osteoporosis patients treated with denosumab at three medical centers and examined their persistence with four doses of denosumab injection over 24 months of treatment. Persistence was defined as the extent to which a patient adhered to denosumab treatment in terms of the prescribed interval and dose, with a permissible gap of 8 weeks. For patients who missed their scheduled treatment appointment(s) during the follow-up period (i.e., no-shows), Cox proportional regression analysis was conducted to explore the factors associated with poor adherence. Several factors were considered, such as age, prior anti-osteoporotic drug use, the treatment provider's medical specialty, the proximity to the medical center, and financial burdens of treatment.

RESULTS

Out of 294 male patients, 77 (26.2%) completed all four sequential rounds of the denosumab treatment. Out of 217 patients who did not complete the denosumab treatment, 138 (63.6%) missed the scheduled treatment(s). Missing treatment was significantly associated with age (odds ratio [OR], 1.03), prior bisphosphonate use (OR, 0.76), and prescription by non-endocrinologists (OR, 2.24). Denosumab was stopped in 44 (20.3%) patients due to medical errors, in 24 (11.1%) patients due to a T-score improvement over -2.5, and in five (2.3%) patients due to expected dental procedures.

CONCLUSION

Our study showed that only one-fourth of Korean male osteoporosis patients were fully adherent to 24 months of denosumab treatment.