Treatment of secondary hyperparathyroidism: How do cinacalcet and etelcalcetide differ?

Etelcalcetide use During Maintenance Hemodialysis and Incidence of Parathyroidectomy After Kidney Transplantation

Introduction

Etelcalcetide is an i.v. calcimimetic agent, effectively reducing parathyroid hormone levels in patients on maintenance hemodialysis (HD). The clinical impact of discontinuing etelcalcetide at the time of kidney transplantation is unknown.

Methods

We retrospectively reviewed all patients on HD meeting predefined criteria who received a kidney transplant at our institution between January 1, 2015, and December 12, 2022. The incidence of parathyroidectomy and the evolution of calcium, phosphate, and intact parathyroid hormone (iPTH) levels after transplantation was analyzed according to the type of calcimimetic treatment before transplantation (cinacalcet vs. etelcalcetide vs. none).

Results

Overall, 372 patients (aged 53 years; interquartile range [IQR]: 42-62 years) were included. At the time of transplantation, 35, 75, and 262 patients were under etelcalcetide, cinacalcet, or no calcimimetic, respectively. After 1064 (IQR: 367-1658) days, the incidences of parathyroidectomy in the etelcalcetide, cinacalcet, no calcimimetic groups were 29%, 12%, and 1%, respectively (P < 0.001). Etelcalcetide was associated with an increased incidence of parathyroidectomy after adjustment for age, sex, and HD vintage (hazard ratio [HR]: 97.0, 95% confidence interval [CI]: 19.1-493.9, P < 0.001). The incidence of parathyroidectomy was related to etelcalcetide dosage (6/11 [54.6%] in patients with ≥ 10 mg vs. 4/24 [16.7%] in patients with < 10 mg, P = 0.02). Moreover, peak calcium levels were higher (P < 0.001) and parathyroidectomy was performed earlier (median 80 vs. 480 days, P < 0.001) in the etelcalcetide compared with the cinacalcet group. Long-term graft function, graft loss, and mortality were similar.

Conclusion

Etelcalcetide use during maintenance HD is associated with an increased incidence of early parathyroidectomy after transplantation compared to cinacalcet or no calcimimetic.

Pharmaceutical Management of Secondary Hyperparathyroidism and the Role of Surgery: A 5-Year Retrospective Study

Background and Objectives: Secondary hyperparathyroidism (SHPT) poses a common condition among patients with chronic kidney disease (CKD) due to the chronic stimulation of the parathyroid glands as a result of persistently low calcium levels. As a first option for medical treatment, vitamin D receptor analogs (VDRAs) and calcimimetic agents are generally used. Apart from cinacalcet, which is orally taken, in recent years, another calcimimetic agent, etelcalcetide, is being administered intravenously during dialysis. Materials and Methods: In a 5-year retrospective study between 2018 and 2023, 52 patients undergoing dialysis were studied. The aim of this study is to highlight the possible effects and/or benefits that intravenously administered calcimimetic agents have on CKD patients. A total of 34 patients (65.4%) received cinacalcet and etelcalcetide while parathormone (PTH) and calcium serum levels were monitored on a monthly basis. Results: A total of 29 out of 33 patients (87.9%) that received treatment with etelcalcetide showed a significant decrease in PTH levels, which rose up to 57% compared to the initial values. None of the included patients needed to undergo parathyroidectomy (PTx) due to either extremely high and persistent PTH levels or severe side effects of the medications. It is generally strongly advised that parathyroidectomies should be performed by an expert surgical team. In recent years, a significant decrease in parathyroidectomies has been recorded globally, a fact that is mainly linked to the constantly wider use of new calcimimetic agents. This decrease in parathyroidectomies has resulted in an important decrease in complications occurring in cervical surgeries (e.g., perioperative hemorrhage and nerve damage). Conslusions: Despite the fact that these surgical complications cannot be easily compared to the pharmaceutical side effects, the recorded decrease in parathyroidectomies is considered to be notable, especially in cases of relapse where a difficult reoperation would be considered based on previously published guidelines.

Neurorescuing effect of Cinacalcet against hypercalcemia-induced nerve injury in chronic kidney disease via TRAF2/cIAP1/KLF2/SERPINA3 signal axis

Hypercalcemia is a common complication in chronic kidney disease (CKD) and unfortunately contributes to nerve injury. This study aims to investigate the potential role and underlying mechanisms of Cinacalcet (CIN) in hypercalcemia-driven nerve injury in CKD. A CKD mouse model was first established by adenine feeding to identify the therapeutic effects of CIN. Molecules related to CIN and CKD were predicted by bioinformatics analysis and their expression in the kidney tissues of CKD mice was measured by immunochemistry. Gain- and loss-of-functions assays were performed both in vitro and in vivo to evaluate their effects on nerve injury in CKD, as reflected by Scr and BUN, and brain calcium content as well as behavior tests. CIN ameliorated hypercalcemia-driven nerve injury in CKD mice. Interactions among TRAF2, an E3-ubiquitin ligase, KLF2, and SERPINA3 were bioinformatically predicted on CIN effect. CIN restricted the ubiquitin-mediated degradation of KLF2 by downregulating TRAF2. KLF2 targeted and inversely regulated SERPINA3 to repress hypercalcemia-driven nerve injury in CKD. CIN was substantiated in vivo to ameliorate hypercalcemia-driven nerve injury in CKD mice through the TRAF2/KLF2/SERPINA3 regulatory axis. Together, CIN suppresses SERPINA3 expression via TRAF2-mediated inhibition of the ubiquitin-dependent degradation of KLF2, thus repressing hypercalcemia-induced nerve injury in CKD mice.

Pathophysiology and Clinical Impacts of Chronic Kidney Disease on Coronary Artery Calcification

The global prevalence of chronic kidney disease (CKD) has increased in recent years. Adverse cardiovascular events have become the main cause of life-threatening events in patients with CKD, and vascular calcification is a risk factor for cardiovascular disease. Vascular calcification, especially coronary artery calcification, is more prevalent, severe, rapidly progressive, and harmful in patients with CKD. Some features and risk factors are unique to vascular calcification in patients with CKD; the formation of vascular calcification is not only influenced by the phenotypic transformation of vascular smooth muscle cells, but also by electrolyte and endocrine dysfunction, uremic toxin accumulation, and other novel factors. The study on the mechanism of vascular calcification in patients with renal insufficiency can provide a basis and new target for the prevention and treatment of this disease. This review aims to illustrate the impact of CKD on vascular calcification and to discuss the recent research data on the pathogenesis and factors involved in vascular calcification, mainly focusing on coronary artery calcification, in patients with CKD.

Upacicalcet, a positive allosteric modulator of the calcium-sensing receptor, prevents vascular calcification and bone disorder in a rat adenine-induced secondary hyperparathyroidism model

Secondary hyperparathyroidism (SHPT) is a major comorbidity of chronic kidney disease (CKD). Chronic elevation of PTH levels is associated with cortical bone deterioration and increase in the risk of fractures in CKD patients. Here, we evaluated the effect of repeated administration of upacicalcet, a novel positive allosteric modulator of the calcium-sensing receptor, in a rat model of adenine-induced renal failure, by determining serum levels of intact PTH (iPTH), calcium, phosphorus, creatinine, and urea nitrogen. Furthermore, parathyroid hyperplasia (parathyroid gland weight and Ki-67-positive cell density), ectopic calcification (calcium content in the thoracic aorta, kidney and heart and positive von Kossa staining in the thoracic aorta), and bone morphometry parameters (cortical porosity and fibrosis volume) were evaluated. Rats treated with either 0.2 mg/kg or 1 mg/kg upacicalcet exhibited significantly lower serum iPTH levels than CKD-control rats, as early as 7 days after the first dose. Repeated administration of upacicalcet reduced serum iPTH levels and inhibited parathyroid hyperplasia in rats with adenine-induced severe renal failure. Moreover, it suppressed ectopic calcification and cortical pore formation. In contrast, serum calcium and phosphorus levels were not significantly affected, suggesting a low risk of hypocalcemia, which often occurs with SHPT treatment. In conclusion, repeated administration of upacicalcet decreased serum iPTH levels and suppressed parathyroid hyperplasia in the adenine-induced CKD rat model of SHPT. Furthermore, ectopic calcification and cortical pore formation were suppressed without significant changes in blood mineral parameters. Upacicalcet safely inhibited the progression of SHPT in an adenine-induced CKD rat model.

Etelcalcetide and Paricalcitol in Chronic Kidney Disease: When the Target Is Inflammation

Introduction: secondary hyperparathyroidism (SHP) is frequent in patients with chronic kidney disease (CKD), particularly in those in dialysis. To treat this complication, the current options available include phosphorus restriction, phosphate binders, the inhibition of parathyroid hormone (PTH) synthesis and secretion by the supplementation of vitamin D or VDR activators, or the use of calcimimetics. Beyond the control of PTH, the effects of the treatment of SHP on other biomarkers of risk may represent an additional benefit for this population. In this study, we explore the benefits of current SHP treatment options, mainly paricalcitol and/or etelcalcetide in the inflammatory state of hemodialysis (HD) patients. Results: the study finally included 142 maintenance HD patients (5 patients were excluded) followed for 6 months (dialysis vintage 26 ± 30 months, mean age 70 years old, 73% women, 81% Spanish white, 47% diabetic). In this case, 52 patients were on regular treatment with paricalcitol for SHP and 25 patients were eligible to initiate etelcalcetide. The baseline serum levels of Ca, P, PTH, Ferritin, albumin, C-reactive protein (CRP), and other variables were measured. We found serum PTH levels showed an improvement after the treatment with etelcalcetide again paricalcitol and no treatment (p < 0.04). Of note, serum levels of CRP were significantly lower in a small group of patients (n = 11) receiving paricalcitol + etelcalcetide compared to paricalcitol or etelcalcetide alone. The proportion of patients with CRP within target ranges (≤1.0 mg/dL) increased significantly after combined treatment (p < 0.001). Conclusions: etelcalcetide proved to safely reduce the PTH levels without significant adverse events and the possibility of a synergic anti-inflammatory effect with the simultaneous use of Paricalcitol in HD patients.

Prediction Model of Postoperative Severe Hypocalcemia in Patients with Secondary Hyperparathyroidism Based on Logistic Regression and XGBoost Algorithm

Objective

A predictive model was established based on logistic regression and XGBoost algorithm to investigate the factors related to postoperative hypocalcemia in patients with secondary hyperparathyroidism (SHPT).

Methods

A total of 60 SHPT patients who underwent parathyroidectomy (PTX) in our hospital were retrospectively enrolled. All patients were randomly divided into a training set (n = 42) and a test set (n = 18). The clinical data of the patients were analyzed, including gender, age, dialysis time, body mass, and several preoperative biochemical indicators. The multivariate logistic regression and XGBoost algorithm models were used to analyze the independent risk factors for severe postoperative hypocalcemia (SH). The forecasting efficiency of the two prediction models is analyzed.

Results

Multivariate logistic regression analysis showed that body mass (OR = 1.203, P = 0.032), age (OR = 1.214, P = 0.035), preoperative PTH (OR = 1.026, P = 0.043), preoperative Ca (OR = 1.062, P = 0.025), and preoperative ALP (OR = 1.031, P = 0.027) were positively correlated with postoperative SH. The top three important features of XGBoost algorithm prediction model were preoperative Ca, preoperative PTH, and preoperative ALP. The area under the curve of the logistic regression and XGBoost algorithm model in the test set was 0.734 (95% CI: 0.595~0.872) and 0.827 (95% CI: 0.722~0.932), respectively.

Conclusion

The predictive models based on the logistic regression and XGBoost algorithm model can predict the occurrence of postoperative SH.

First-in-Human Phase I Study of the Novel Injectable Calcimimetic Agent Upacicalcet in Healthy Adult Japanese Participants

Background and Objective

Upacicalcet sodium hydrate is a novel small-molecule calcimimetic and has potential as a therapeutic agent for secondary hyperparathyroidism. We assessed the pharmacokinetics, pharmacodynamics, safety, and tolerability of a single intravenous dose of upacicalcet in Japanese healthy adults.

Method

This was a single-center, double-blinded, randomized, placebo-controlled, dose-escalation study. For each cohort, eight subjects were randomly assigned at a ratio of 3:1 to receive a single injection of placebo or upacicalcet 0.01, 0.1, 1.0, or 2.5 mg.

Result

The plasma concentration of upacicalcet increased in a dose-dependent manner. Upacicalcet rapidly disappeared from plasma after administration. The half-life of upacicalcet was approximately 1–2 h. The major excretion route of upacicalcet was via urine. Serum intact parathyroid hormone decreased in accordance with the upacicalcet dose, from the lowest dose of 0.01 mg. Gastrointestinal disorders occurred in one patient in the 1.0 mg group and in five patients in the 2.5 mg group. All adverse events were nonserious, and no symptomatic hypocalcemia occurred.

Conclusion

This study showed that upacicalcet acted as a calcimimetic and was excreted in the urine unchanged with little metabolism. Moreover, upacicalcet is a small molecule and has a small volume of distribution. In addition, less than 50% of upacicalcet binds to human plasma proteins. These findings suggest that upacicalcet administered to patients undergoing hemodialysis might be expected to have a long excretion period and sustained pharmacological effect.

Severe Symptomatic Hypocalcemia, complicating cardiac arrhythmia following Cinacalcet (SensiparTM) administration: A Case Report

Clinicians should closely monitor patients on calcimimetics for hypocalcemic symptoms and arrhythmia, even though asymptomatic hypocalcemia typically resolves without intervention.

Ultrasound-guided bilateral superficial cervical plexus block enhances the quality of recovery of uremia patients with secondary hyperparathyroidism following parathyroidectomy: a randomized controlled trial

Background

Parathyroidectomy has been proposed as a method for reducing parathyroid hormone levels. We evaluated the effects of ultrasound-guided bilateral superficial cervical plexus block (BSCPB) on the quality of recovery of uremia patients with secondary hyperparathyroidism (SHPT) following parathyroidectomy.

Methods

Eighty-two uremia patients who underwent parathyroidectomy and exhibited SHPT were randomly allocated to the BSCPB group or the control group (CON group). The patients received ultrasound-guided BSCPB with 7.5 ml of ropivacaine 0.5% on each side (BSCPB group) or equal amount of 0.9% normal saline (CON group). The primary outcome of the Quality of Recovery-40(QoR-40) score was recorded on the day before surgery and postoperative day 1(POD1). Secondary outcomes including total consumption of remifentanil, time to first required rescue analgesia, number of patients requiring rescue analgesia, and total consumption of tramadol during the first 24 h after surgery were recorded. The occurrence of postoperative nausea or vomiting (PONV) and the visual analogue scale (VAS) scores were assessed and recorded.

Results

The scores on the pain and emotional state dimensions of the QoR-40 and the total QoR-40 score were higher in the BSCPB group than in the CON group on POD1 (P = 0.000). Compared with the CON group, the total consumption of remifentanil was significantly decreased in the BSCPB group (P = 0.000). The BSCPB group exhibited longer time to first required rescue analgesia (P = 0.018), fewer patients requiring rescue analgesia (P = 0.000), and lower postoperative total consumption of tramadol during the first 24 h after surgery (P = 0.000) than the CON group. The incidence of PONV was significantly lower in the BSCPB group than in the CON group (P = 0.013). The VAS scores in the BSCPB group were lower than those in the CON group at all time-points after surgery (P = 0.000).

Conclusion

Ultrasound-guided BSCPB with ropivacaine 0.5% can enhance the quality of recovery, postoperative analgesia, and reduce the incidence of PONV in uremia patients with SHPT following parathyroidectomy.

Trial registration

ChiCTR1900027185 . (Prospective registered). Initial registration date was 04/11/2019.

Severe hypercalcaemia early after kidney transplantation in two patients with severe secondary hyperparathyroidism previously treated with etelcalcetide

Cinacalcet and, more recently, etelcalcetide revolutionized the treatment of chronic kidney disease-mineral and bone disorder (CKD-MBD). Kidney transplant (KT) usually improves CKD-MBD. However, a significant proportion of KT recipients have high serum calcium levels, not requiring any treatment. We report two patients previously treated with etelcalcetide who developed severe (>3.3 mmol/L) hypercalcaemia in the early post-KT course, requiring parathyroidectomy. Pathological studies showed parathyroid adenomas and hyperplasia. One patient had a graft biopsy showing numerous intratubular calcium phosphate crystals. These observations should prompt pharmacovigilance studies and careful follow-up of KT recipients previously treated with etelcalcetide.

Pharmacogenetic and safety analysis of cinacalcet hydrochloride in healthy Chinese subjects

BACKGROUND

Our study aims to explore the effect of genetics on the pharmacodynamics (PD) and pharmacokinetics (PK) of cinacalcet in healthy Chinese subjects; to investigate the effect of dietary factors on cinacalcet, and to evaluate the safety of cinacalcet under fasting and non-fasting conditions using a bioequivalence trial.

METHODS

We investigated the relationship of cinacalcet PK with single nucleotide polymorphisms (SNPs) of CYP3A4, CYP1A2 and CYP2D6, and of cinacalcet PD with SNPs of calcium-sensitive receptors (CASR) and vitamin D receptors (VDR) in 65 healthy Chinese subjects recruited to participate in this study. Our study was a phase I, open-label, randomized, two-period, two-sequence crossover, a single-center clinical study designed under both fasting and non-fasting conditions to investigate the effect of dietary factors on cinacalcet. Plasma cinacalcet concentrations were analyzed using a validated HPLC-MS/MS assay. Clinical laboratory tests evaluated safety. Thirteen SNPs of CASR, VDR, and CYP genes were selected for pharmacogenetic analysis.

RESULTS

CYP3A4 rs4646437 was found to be associated with the PK of cinacalcet under fasting conditions (P<0.01). Subjects carrying T alleles of rs4646437 appeared to metabolize cinacalcet poorly. The C_max and AUC of subjects in the non-fasting group were significantly higher (P<0.0001) than those in the fasting group. The T_max, CL/F, and Vd/F in the fasting group were significantly higher (P<0.0001) than those in the non-fasting group. In the fasting group, the geometric least square mean ratios (T/R) of the C_max and AUC_0-t were 109.89% and 105.33%, and the corresponding 90% CIs were 98.36-122.79% and 98.04-113.15%, respectively. In the non-fasting group, the T/R of the C_max and AUC_0-t were 100.74% and 99.09%, and the corresponding 90% CIs were 92.65-109.54% and 94.79-103.58%, respectively. All adverse events (AEs) were mild, and no serious adverse events (SAEs) occurred during the bioequivalence trial.

CONCLUSIONS

Following our investigation, we reached the following conclusions: CYP3A4 rs4646437 may affect cinacalcet PK; the reference and test preparations of cinacalcet were bioequivalent under fasting and non-fasting conditions and were safe to use; and dietary factors had a significant effect on the PK of cinacalcet, in that exposure to the drug increased when cinacalcet was taken after eating.

New Intravenous Calcimimetic Agents: New Options, New Problems. An Example on How Clinical, Economical and Ethical Considerations Affect Choice of Treatment

BACKGROUND

Dialysis treatment is improving, but several long-term problems remain unsolved, including metabolic bone disease linked to chronic kidney disease (CKD-MBD). The availability of new, efficacious but expensive drugs (intravenous calcimimetic agents) poses ethical problems, especially in the setting of budget limitations.

METHODS

Reasons of choice, side effects, biochemical trends were discussed in a cohort of 15 patients (13% of the dialysis population) who stared treatment with intravenous calcimimetics in a single center. All patients had previously been treated with oral calcimimetic agents; dialysis efficacy was at target in 14/15; hemodiafiltration was employed in 10/15. Median Charlson Comorbidity Index was 8. The indications were discussed according to the principlist ethics (beneficience, non maleficience, justice and autonomy). Biochemical results were analyzed to support the clinical-ethical choices.

RESULTS

In the context of a strict clinical and biochemical surveillance, the lack of side effects ensured "non-maleficence"; efficacy was at least similar to oral calcimimetic agents, but tolerance was better. Autonomy was respected through a shared decision-making model; all patients appreciated the reduction of the drug burden, and most acknowledged better control of their biochemical data. The ethical conflict resides in the balance between the clinical "beneficience, non-maleficience" advantage and "justice" (economic impact of treatment, potentially in attrition with other resources, since the drug is expensive and included in the dialysis bundle). The dilemma is more relevant when a patient's life expectancy is short (economic impact without clear clinical advantages), or when non-compliance is an issue (unclear advantage if the whole treatment is not correctly taken).

CONCLUSIONS

In a context of person-centered medicine, autonomy, beneficence and non-maleficence should weight more than economic justice. While ethical discussions are not aimed at finding "the right answer" but asking "the right questions", this example can raise awareness of the importance of including an ethical analysis in the choice of "economically relevant" drugs.

Evaluating extended-release calcifediol as a treatment option for chronic kidney disease-mineral and bone disorder (CKD-MBD)

Introduction: Extended-release calcifediol (ERC) is an orally administered prohormone of active vitamin D (1,25-dihydroxyvitamin D [1,25D]) designed to safely and sufficiently increase serum total 25-hydroxyvitamin D (25D) to reduce elevated parathyroid hormone (PTH) in patients with non-dialysis-chronic kidney disease (ND-CKD). ERC is currently approved in the United States and Canada.Areas covered: Herein, key clinical data relating to the pharmacokinetics, pharmacodynamics, efficacy and safety of ERC are reviewed.Expert opinion: Currently available treatment options for secondary hyperparathyroidism (SHPT) in ND-CKD have limitations: the effectiveness of nutritional vitamin D supplements for reduction of PTH levels is unproven and active (1α-hydroxylated) vitamin D analogues elevate serum calcium, which increases the risk of hypercalcemia and vascular calcification. Clinical studies show that ERC is an effective, well tolerated treatment for SHPT in ND-CKD. ERC gradually raises serum 25D levels, resulting in physiologically regulated increases in serum 1,25D and sustained reductions in PTH, while avoiding clinically meaningful increases in serum phosphorus, calcium and fibroblast growth factor 23. ERC offers a new, effective and well tolerated treatment option for the early management of SHPT in patients with ND-CKD.

Controversies in the Management of Secondary Hyperparathyroidism in Chronic Kidney Disease

Secondary hyperparathyroidism is a frequent complication of chronic kidney disease that begins early in the course of renal insufficiency as an adaptive response to maintain mineral homeostasis. This complex disorder affects the bone, leading to an increase in fracture risk and is associated with increased risks of vascular calcification and mortality. PURPOSE OF REVIEW: In this review, we examine the different strategies available to manage secondary hyperparathyroidism. Particularly, we focus on the adequate control of serum phosphorus by restricting intake and the use of phosphate binders, correction of hypocalcemia while minimizing calcium burden, and reduction in PTH levels through the use of vitamin D sterols and calcimimetics. RECENT FINDINGS: It was observed that although numerous agents directed at the correction of these abnormalities have demonstrated effectiveness on biochemical markers, there is still a relative scarcity of studies demonstrating treatment effectiveness as measured by hard clinical outcomes. In addition, most agents have side effects that may limit their use, even in patients in which the treatment has demonstrated efficacy in controlling these parameters. There is still controversy as to what therapeutic regimens to choose for a particular patient and what parameter should be used to follow their effects, including outcomes, side effects, pill burden, and costs, among others. In the present article, we analyze controversial aspects of the different therapeutic agents available. Although many tools and regimens are available, no one by itself is enough for an adequate management of the patient. But rather, combined therapy and individualization of approaches are recommended for better results. We suggest that new studies analyzing the effectiveness of therapeutic approaches to the management of secondary hyperparathyroidism should be directed not only to controlling parathyroid hormone levels but also to the evaluation of long-term outcomes, based on modification of morbidity, mortality, and end organ impact, while reducing side effects and controlling costs, among others.