Severe Hypocalcemia With Denosumab Among Older Female Dialysis-Dependent Patients.

Importance: Dialysis-dependent patients experience high rates of morbidity from fractures, yet little evidence is available on optimal treatment strategies. Chronic kidney disease-mineral and bone disorder is nearly universal in dialysis-dependent patients, complicating diagnosis and treatment of skeletal fragility. Objective: To examine the incidence and comparative risk of severe hypocalcemia with denosumab compared with oral bisphosphonates among dialysis-dependent patients treated for osteoporosis. Design, Setting, and Participants: Retrospective cohort study of female dialysis-dependent Medicare patients aged 65 years or older who initiated treatment with denosumab or oral bisphosphonates from 2013 to 2020. Clinical performance measures including monthly serum calcium were obtained through linkage to the Consolidated Renal Operations in a Web-Enabled Network database. Exposures: Denosumab, 60 mg, or oral bisphosphonates. Main Outcomes and Measures: Severe hypocalcemia was defined as total albumin-corrected serum calcium below 7.5 mg/dL (1.88 mmol/L) or a primary hospital or emergency department hypocalcemia diagnosis (emergent care). Very severe hypocalcemia (serum calcium below 6.5 mg/dL [1.63 mmol/L] or emergent care) was also assessed. Inverse probability of treatment-weighted cumulative incidence, weighted risk differences, and weighted risk ratios were calculated during the first 12 treatment weeks. Results: In the unweighted cohorts, 607 of 1523 denosumab-treated patients and 23 of 1281 oral bisphosphonate-treated patients developed severe hypocalcemia. The 12-week weighted cumulative incidence of severe hypocalcemia was 41.1% with denosumab vs 2.0% with oral bisphosphonates (weighted risk difference, 39.1% [95% CI, 36.3%-41.9%]; weighted risk ratio, 20.7 [95% CI, 13.2-41.2]). The 12-week weighted cumulative incidence of very severe hypocalcemia was also increased with denosumab (10.9%) vs oral bisphosphonates (0.4%) (weighted risk difference, 10.5% [95% CI, 8.8%-12.0%]; weighted risk ratio, 26.4 [95% CI, 9.7-449.5]). Conclusions and Relevance: Denosumab was associated with a markedly higher incidence of severe and very severe hypocalcemia in female dialysis-dependent patients aged 65 years or older compared with oral bisphosphonates. Given the complexity of diagnosing the underlying bone pathophysiology in dialysis-dependent patients, the high risk posed by denosumab in this population, and the complex strategies required to monitor and treat severe hypocalcemia, denosumab should be administered after careful patient selection and with plans for frequent monitoring.

Overcoming Barriers to Drug Development in Children with CKD.

Like all sick children, children with CKD need access to safe and effective medicines that have been formulated and examined specifically for them. Despite legislation in the United States and the European Union that either mandates or incentivizes programs for children, conducting trials to advance the treatment of children continues to prove to be a challenge for drug developers. This is also the case for drug development in children with CKD, where trials face challenges in recruitment and completion and where there remains a substantial time lag between initial approval of a medicinal product for use in adults and completion of studies that result in the addition of pediatric-specific labeling for the same indication. The Kidney Health Initiative commissioned a workgroup of diverse stakeholders ( https://khi.asn-online.org/projects/project.aspx?ID=61 ), including participants from the Food and Drug Administration and the European Medicines Agency, to think carefully through the challenges in drug development for children with CKD and how to overcome them. This article provides an overview of the regulatory frameworks in the United States and the European Union that govern pediatric drug development, the current landscape of drug development and approval for children with CKD, the challenges in conduct and execution of these drug trials, and the progress that has been made to facilitate drug development for children with CKD.

Association Between Changes in CMS Reimbursement Policy and Drug Labels for Erythrocyte-Stimulating Agents With Outcomes for Older Patients Undergoing Hemodialysis Covered by Fee-for-Service Medicare.

IMPORTANCE: In 2011, the US Centers for Medicare & Medicaid Services (CMS) changed its reimbursement policy for hemodialysis to a bundled comprehensive payment system that included the cost of erythrocyte-stimulating agents (ESAs). Also in 2011, the US Food and Drug Administration revised the drug label for ESAs, recommending more conservative dosing in patients with chronic kidney disease. In response to concerns that these measures could have adverse effects on patient care and outcomes, the CMS and the FDA initiated a collaboration to assess the effect. OBJECTIVE: To assess the effects of the changes in reimbursement policy and the ESA drug label on patients who underwent incident hemodialysis. DESIGN, SETTING, AND PARTICIPANTS: For this retrospective cohort study, patients 66 years or older who had undergone incident hemodialysis, and were enrolled in Medicare parts A, B, or D for at least 12 months prior to hemodialysis initiation between January 1, 2008, and December 31, 2013, were recruited from hemodialysis centers across the United States. Patients were divided into 2 cohorts based on their date of hemodialysis initiation and followed: January 1, 2008, to December 31, 2009, for the prepolicy cohort and July 1, 2011, to June 30, 2013, for the postpolicy cohort, with the exclusion of January 1, 2010, to June 30, 2011, as a transition period. INTERVENTIONS: Changes in CMS reimbursement policy for dialysis and the FDA label for ESAs. MAIN OUTCOMES AND MEASURES: Major adverse cardiovascular events (MACEs), including acute myocardial infarction (AMI), stroke, and all-cause mortality; hospitalized congestive heart failure (H-CHF); venous thromboembolism; and red blood cell transfusions. Secondary outcomes included evaluating effects on black and other patient subgroups. RESULTS: Baseline characteristics of the 69 718 incident hemodialysis patients were similar between cohorts. Compared with the prepolicy period, the risk of MACE, death, H-CHF, and venous thromboembolism were similar in the postpolicy period, and the risk of stroke decreased (hazard ratio [HR], 0.77; 95% CI, 0.64-0.93; P = .01); the use of ESAs also decreased, and the rate of blood transfusions increased (HR, 1.09; 95% CI, 1.07-1.12; P < .001). In the post-postpolicy period, black patients had a significant reduction in risk of MACE (HR, 0.82; 95% CI, 0.73-0.92; P < .001) and all-cause mortality (HR, 0.82; 95% CI, 0.73-0.93; P = .002). CONCLUSIONS AND RELEVANCE: After the bundling policy and ESA labeling changes in 2011, the risks of MACE and death for patients 66 years or older and covered by fee-for-service Medicare who had undergone incident hemodialysis did not change; the risk of stroke was reduced, and the rate of blood transfusions modestly increased. Black patients had substantial reductions in the risks of MACE and death.

Glomerular Diseases: Registries and Clinical Trials.

Nephrology has conducted few high-quality clinical trials, and the trials that have been conducted have not resulted in the approval of new treatments for primary or inflammatory glomerular diseases. There are overarching process issues that affect the conduct of all clinical trials, but there are also some specialty-specific issues. Within nephrology, primary glomerular diseases are rare, making adequate recruitment for meaningful trials difficult. Nephrologists need better ways, beyond histopathology, to phenotype patients with glomerular diseases and stratify the risk for progression to ESRD. Rigorous trial design is needed for the testing of new therapies, where most patients with glomerular diseases are offered the opportunity to enroll in a clinical trial if standard therapies have failed or are lacking. Training programs to develop a core group of kidney specialists with expertise in the design and implementation of clinical trials are also needed. Registries of patients with glomerular disease and observational studies can aid in the ability to determine realistic estimates of disease prevalence and inform trial design through a better understanding of the natural history of disease. Some proposed changes to the Common Rule, the federal regulations governing the ethical conduct of research involving humans, and the emerging use of electronic health records may facilitate the efficiency of initiating multicenter clinical trials. Collaborations among academia, government scientific and regulatory agencies, industry, foundations, and patient advocacy groups can accelerate therapeutic development for these complex diseases.