Long-term effects of etelcalcetide as intravenous calcimimetic therapy in hemodialysis patients with secondary hyperparathyroidism

Phase 2 study of upacicalcet in Japanese haemodialysis patients with secondary hyperparathyroidism: an intraindividual dose-adjustment study

Background

Upacicalcet is a novel small-molecule calcimimetic agent developed for intravenous injection. Here, we evaluated the long-term efficacy and safety of upacicalcet treatment via intraindividual dose adjustment in haemodialysis patients with secondary hyperparathyroidism (SHPT).

Methods

A phase 2, multicentre, open-label, single-arm study was conducted. Upacicalcet was administered for 52 weeks; the starting dose was 50 μg thrice a week, and then adjusted to 25, 50, 100, 150, 200, 250, or 300 μg, according to the dose-adjustment method set in the protocol. The primary endpoint was the percentage of patients with serum intact parathyroid hormone (iPTH) level achieving a target range of 60-240 pg/mL (target achievement rate) at week 18.

Results

A total of 58 patients were administered upacicalcet. The target achievement rate of serum iPTH level at week 18 was 57.9%, which increased to 80.8% at week 52. The serum-corrected calcium (cCa) level decreased immediately after upacicalcet administration, but no further decrease was observed. Adverse events were observed in 94.8% of patients, and adverse drug reactions (ADRs) occurred in 20.7% of patients. The most common ADR was decreased adjusted calcium in eight patients; dizziness occurred as a serious ADR in one patient. The serum cCa level of patients who interrupted upacicalcet treatment at a serum cCa level of <7.5 mg/dL recovered to ≥7.5 mg/dL immediately after the interruption.

Conclusions

In haemodialysis patients with SHPT, upacicalcet doses of 25-300 μg for 52 weeks were found to be highly effective and well-tolerated, with minor safety concerns.

Long-term use of etelcalcetide for the treatment of secondary hyperparathyroidism in patients undergoing hemodialysis for end-stage renal failure: a real-life retrospective observational study

BACKGROUND

Patients with end-stage renal failure (ESRD) or dialysis frequently suffer from secondary hyperparathyroidism (sHPTH), a severe complication of mineral metabolism disorders. The calcimimetic etelcalcetide has been approved and shown efficacy in randomized controlled trials, however, data are limited from real-life studies. This study aimed to evaluate the long-term use etelcalcetide for the treatment of sHPTH (PTH > 600 pg/mL) in patients undergoing extracorporeal hemodialysis for ESRD for at least 2 years.

METHODS

In 45 patients, we administered etelcalcetide for the treatment of sHPTH (PTH > 600 pg/mL); One group of patients (control group, Group A; N = 26) were previously treated with intravenous vitamin D analogues only (paricalcitol 5 µg/ml, three times/week) and then treated with etelcalcetide and a second group of patients already on cinacalcet therapy for at least six months in combination with iv paricalcitol were switched to etelcalcetide (Group B, N = 19).

RESULTS

PTH levels decreased over time in both groups of patients, with higher values for patients previously treated with cinacalcet (Group B) compared to Group A for the entire study duration even if the final value of the two groups was comparable. After 12 months, the percentage of subjects who had PTH concentrations within the targets recommended by KDIGO guidelines was 87% in Group A and 58% in Group B. In seven patients, despite a parathyroid gland volume > 1000 mm³, an adequate response in the reduction of PTH was obtained.

CONCLUSION

Findings from this study demonstrate that the efficacy of etelcalcetide is maintained over the long term.

Old and New Drugs for the Management of Bone Disorders in CKD

Disturbances in mineral and bone metabolism are common in patients with chronic kidney disease (CKD), especially those undergoing dialysis. Renal osteodystrophy, which describes an alteration of bone morphology, is an important component of this systemic disorder and may explain the elevated risk of fracture which adversely affects morbidity and mortality. The most common form of renal osteodystrophy is high-turnover bone disease (osteitis fibrosa), which is induced by secondary hyperparathyroidism (SHPT). During the past decade, there has been considerable advances in the management of SHPT, with the introduction of the calcimimetic agents, the optimized use of nutritional and active vitamin D, and the accumulated experience with surgical parathyroidectomy. Studies supported that these advances could translate into improvement of renal bone disease and fracture prevention, as well as decreasing the risk of cardiovascular events and mortality. In this review, we summarize the available clinical evidence on the effect of old and new drugs on bone disorders in patients with CKD.

One-year safety and efficacy of intravenous etelcalcetide in patients on hemodialysis with secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism (sHPT), a common complication of chronic kidney disease, is characterized by elevated serum parathyroid hormone (PTH). Etelcalcetide is an intravenous calcimimetic that increases sensitivity of the calcium-sensing receptor to calcium and decreases PTH secretion. This open-label extension (OLE) trial evaluated the long-term effects of etelcalcetide for sHPT treatment in patients receiving hemodialysis.

METHODS

This 52-week, multicenter, single-arm OLE enrolled patients from three parent trials: two randomized, double-blind, placebo-controlled trials and one open-label, single-arm, 'switch' study from cinacalcet to etelcalcetide. The primary endpoint was to investigate the nature, frequency, severity and relation to treatment of all adverse events (AEs) reported throughout the trial. Secondary endpoints included the proportion of patients with >30% reduction from baseline in PTH and the percentage change from baseline in PTH, albumin-corrected calcium (Ca), phosphate (P) and the calcium-phosphate product (Ca × P).ClinicalTrials.gov identifier: NCT01785875; Amgen study: 20120231.

RESULTS

Overall, 89.8% of the patients experienced one or more treatment-emergent AE. The most common were decreased blood Ca (43.3%), diarrhea (10.8%), vomiting (10.4%) and nausea (9.6%); symptomatic hypocalcemia occurred in 3.7% of the patients. Approximately 68% of patients achieved >30% reduction in PTH, and ∼56% achieved PTH ≤300 pg/mL. Mean percent changes from baseline ranged from -25.4% to -26.1% for PTH, -8.3% to -9.1% for Ca, -3.6% to -4.1% for P and -12.0% to -12.6% for Ca × P.

CONCLUSIONS

Etelcalcetide effectively lowered PTH and its effect was sustained, while no new safety concerns emerged over a 1-year treatment period.

Recent advances in understanding and managing secondary hyperparathyroidism in chronic kidney disease

Secondary hyperparathyroidism is a complex pathology that develops as chronic kidney disease progresses. The retention of phosphorus and the reductions in calcium and vitamin D levels stimulate the synthesis and secretion of parathyroid hormone as well as the proliferation rate of parathyroid cells. Parathyroid growth is initially diffuse but it becomes nodular as the disease progresses, making the gland less susceptible to be inhibited. Although the mechanisms underlying the pathophysiology of secondary hyperparathyroidism are well known, new evidence has shed light on unknown aspects of the deregulation of parathyroid function. Secondary hyperparathyroidism is an important feature of chronic kidney disease-mineral and bone disorder and plays an important role in the development of bone disease and vascular calcification. Thus, part of the management of chronic kidney disease relies on maintaining acceptable levels of mineral metabolism parameters in an attempt to slow down or prevent the development of secondary hyperparathyroidism. Here, we will also review the latest evidence regarding several aspects of the clinical and surgical management of secondary hyperparathyroidism.

Safety and efficacy of etelcalcetide, an intravenous calcimimetic, for up to 52 weeks in hemodialysis patients with secondary hyperparathyroidism: results of a post-marketing surveillance in Japan

Background

Etelcalcetide is a second-generation calcimimetic for the management of secondary hyperparathyroidism (SHPT) in patients on dialysis. We performed a post-marketing surveillance (PMS) to obtain information on the safety and efficacy of etelcalcetide in clinical practice in Japan.

Methods

This PMS enrolled SHPT patients who started initial treatment with etelcalcetide between April 1, 2017 and February 28, 2018 in Japan. Safety [adverse drug reactions (ADRs)] and efficacy [serum intact parathyroid hormone (iPTH), corrected calcium (cCa), phosphorous (P), and alkaline phosphatase (ALP)] were recorded for up to 52 weeks or until treatment discontinuation. Treatment decisions were at the physician’s discretion.

Results

Of 1226 patients enrolled across 282 centers, safety and efficacy data were available for 1195 and 1192, respectively, while 933 continued treatment to Week 52. The starting dose was 5 mg in 82.0% of patients. There were 218 ADRs in 169 patients (14.1%). Metabolism and nutrition disorders (8.8%), adverse laboratory test results (1.8%), and gastrointestinal disorders (1.6%) were the most frequent classes of ADRs. Hypocalcemia-related ADRs occurred in 104 patients (8.7%). The percentage of patients with iPTH levels within the target range (60–240 pg/mL) steadily increased from 19.5% at Week 0 to 64.1% at Week 52 or last dose. cCa, P, and ALP levels remained well controlled.

Conclusion

This was the first real-world, large-scale, long-term observational PMS of etelcalcetide in Japan. We did not observe any new safety concerns. Etelcalcetide was associated with clinically relevant improvements in serum iPTH and maintenance of serum cCa, P, and ALP levels.

Electronic supplementary material

The online version of this article (10.1007/s10157-020-01936-2) contains supplementary material, which is available to authorized users.

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.

Influence of dialysate Ca concentrations on the therapeutic effects of etelcalcetide with concomitant drugs in patients with secondary hyperparathyroidism

Aim

Secondary hyperparathyroidism (SHPT), a complication of haemodialysis, is commonly treated with calcimimetics. The impact of dialysates containing different calcium (Ca) concentrations on clinical efficacy of calcimimetics are unclear. We examined whether dialysate Ca concentrations influence the efficacy and dosing of etelcalcetide with concomitant drugs.

Methods

We performed post hoc analyses of a 52‐week, open‐label, multicentre study of etelcalcetide in Japanese SHPT patients to determine whether dialysate Ca influences the therapeutic effects of etelcalcetide with concomitant drugs. We evaluated the differences in serum intact parathyroid hormone (iPTH), corrected Ca (cCa) and phosphate levels among three dialysate Ca concentration groups (2.5, 2.75 or 3.0 mEq/L Ca). Tartrate‐resistant acid phosphatase 5b (TRACP‐5b) and bone alkaline phosphatase (BAP) levels were also compared. Since the dialysate Ca concentration may influence dose adjustment, we assessed the etelcalcetide and concomitant drug doses.

Results

There were no clinically meaningful differences in iPTH, cCa and phosphate levels among the 2.5, 2.75 and 3.0 mEq/L groups (n = 34, 64 and 35, respectively) over 52 weeks. At Week 52, more than 82%, 71% and 67% of patients had iPTH, cCa and phosphate levels within target ranges (60‐240 pg/mL, 8.4‐10.0 mg/dL and 3.5‐6.0 mg/dL, respectively) across the three groups. TRACP‐5b and BAP levels decreased by Week 52 regardless of dialysate Ca. Changes in etelcalcetide and concomitant drug doses were generally similar in each group.

Conclusion

The efficacy and dosing of etelcalcetide with concomitant drugs were essentially unaffected by the dialysate Ca concentration. Patients showed improvements in bone hypermetabolism during treatment.

This is a small observational study of the effect of dialysate calcium concentrations on etelcalcetide with concomitant drugs in secondary hyperparathyroidism. No statistically significant differences were found between the different dialysate calcium groups suggesting that calcium concentrations in the dialysate do not modulate the effect of etelcalcetide.

Secondary Hyperparathyroidism: Pathogenesis and Latest Treatment

The classic pathogenesis of secondary hyperparathyroidism (SHPT) began with the trade-off hypothesis based on parathyroid hormone hypersecretion brought about by renal failure resulting from a physiological response to correct metabolic disorder of calcium, phosphorus, and vitamin D. In dialysis patients with failed renal function, physiological mineral balance control by parathyroid hormone through the kidney fails and hyperparathyroidism progresses. In this process, many significant genetic findings have been established. Abnormalities of Ca-sensing receptor and vitamin D receptor are associated with the pathogenesis of SHPT, and fibroblast growth factor 23 has also been shown to be involved in the pathogenesis. Vitamin D receptor activators (VDRAs) are widely used for treatment of SHPT. However, VDRAs have calcemic and phosphatemic effects that limit their use to a subset of patients, and calcimimetics have been developed as alternative drugs for SHPT. Hyperphosphatemia also affects progression of SHPT, and control of hyperphosphatemia is, therefore, thought to be fundamental for control of SHPT. Currently, a combination of a VDRA and a calcimimetic is recognized as the optimal strategy for SHPT, and for other outcomes such as reduced cardiovascular disease and improved survival. The latest findings on the pathogenesis and treatment of SHPT are summarized in this review.

Effects of the Intravenous Calcimimetic Etelcalcetide on Bone Turnover and Serum Fibroblast Growth Factor 23: Post Hoc Analysis of an Open-label Study

PURPOSE

Secondary hyperparathyroidism (SHPT) is a serious complication that increases the risk of bone disorders in patients with chronic kidney disease (CKD) undergoing hemodialysis. Etelcalcetide is the first injectable calcimimetic approved for treatment of SHPT, which reduces bone turnover markers and suppresses intact fibroblast growth factor 23 (iFGF-23). This study aimed to explore the associations between etelcalcetide-induced changes in circulating factors and serum iFGF-23 levels.

METHODS

This study was a post hoc analysis of data from a previous multicenter, open-label study of etelcalcetide administered to 191 Japanese patients with SHPT undergoing hemodialysis for 52 weeks. Correlations were analyzed between changes from baseline in serum iFGF-23 and serum intact parathyroid hormone (iPTH), corrected calcium, phosphate, bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase-5b (TRACP-5b), and 1α,25-dihydroxyvitamin D (1,25[OH]₂D) levels at 1, 2, 3, 6, and 12 months. Akaike's Information Criterion (AIC) was calculated using serum iPTH, corrected calcium, phosphate, BAP, TRACP-5b, and 1,25(OH)₂D levels as potential predictor variables at each time point. Four models with the smallest AIC at the 3-month time point were chosen as the fitted models to predict changes in iFGF-23 levels, and stepwise multivariate analysis was performed to determine the predictor variables with the greatest contribution to the change in iFGF-23 levels by calculating the partial coefficients of determination.

FINDINGS

The etelcalcetide-induced reduction in iFGF-23 was positively correlated with serum levels of corrected calcium and phosphate and negatively with BAP. By calculating the AIC, corrected calcium, phosphate, iPTH, BAP, and TRACP-5b were suggested to be predictors of iFGF-23 levels. Stepwise multivariate analysis found that phosphate, corrected calcium, BAP, and TRACP-5b correlated with iFGF-23, in order from strongest to weakest.

IMPLICATIONS

These results suggest that etelcalcetide effectively lowered iFGF-23 and that this reduction may occur via improvements in phosphate, corrected calcium, BAP, and TRACP-5b. Etelcalcetide is thus a promising calcimimetic for decreasing iFGF-23 and improving bone turnover in patients with CKD undergoing hemodialysis with severe SHPT, in addition to decreasing PTH itself. JapicCTI identifier: 142,665.

Pharmacology of Parsabiv® (etelcalcetide, ONO-5163/AMG 416), a novel allosteric modulator of the calcium-sensing receptor, for secondary hyperparathyroidism in hemodialysis patients

Etelcalcetide hydrochloride (Parsabiv^®, ONO-5163/AMG 416) is an allosteric modulator of the calcium (Ca)-sensing receptor that was originally produced by KAI Pharmaceuticals Inc. (now Amgen Inc.). It has recently been approved as the first intravenous calcimimetic agent for secondary hyperparathyroidism (SHPT) in many countries. Etelcalcetide is an intravenous injectable drug that can be administered and eliminated through the dialysis circuit in chronic kidney disease patients. In the present study, we evaluated the in vitro pharmacological profile and in vivo parathyroid hormone (PTH)- and Ca-lowering activities of etelcalcetide in a rat 5/6 nephrectomy model of chronic renal insufficiency with SHPT. Etelcalcetide increased the intracellular Ca concentration in HEK-293T cells expressing human Ca-sensing receptor with an EC₅₀ value (95% confidence interval) of 0.53 μM (0.28-1.0 μM) and suppressed PTH secretion from rat parathyroid gland cells with 0.36 μM (0.24-0.54 μM) by activating Ca-sensing receptor. The specificity of etelcalcetide was evaluated by examining its ability to stimulate or inhibit radioligand binding to a panel of 34 off-target proteins. There were no significant changes in the presence of 10 μM etelcalcetide. Furthermore, in a rat 5/6 nephrectomy model of chronic renal insufficiency with SHPT, single intravenous administration of etelcalcetide at 0.3, 1.0, and 3.0 mg/kg decreased plasma PTH and serum Ca levels. Taken together, the present findings identify etelcalcetide as a calcimimetic with potent PTH- and Ca-lowering effects via Ca-sensing receptor agonist activity.

Treatment of secondary hyperparathyroidism in patients on hemodialysis using a novel synthetic peptide calcimimetic, etelcalcetide: a short-term clinical study

Objective

Secondary hyperparathyroidism (SHPT) is a major complication in patients with chronic kidney disease (CKD). SHPT is related to chronic kidney disease-mineral bone disorder, leading to increased morbidity and mortality. Etelcalcetide is intravenously administered at the end of hemodialysis (HD). Etelcalcetide differs from the oral calcimimetic cinacalcet because it reduces gastrointestinal adverse events, thereby improving therapeutic effects. Etelcalcetide has only been approved by the U.S. Food and Drug Administration for several months. Therefore, there have only been a few reports regarding treatment of SHPT using etelcalcetide. This study aimed to evaluate the efficacy of etelcalcetide in patients on HD with SHPT.

Methods

Nine patients on HD (four men and five women, aged 58 ± 10 years) were enrolled in this study. All of the patients received etelcalcetide (5–10 mg, three times a week after HD). The observation period was 4.4 ± 1.0 months.

Results

All of the patients showed a significant reduction in serum parathyroid hormone levels during the observation period (−59% ± 20%). No significant adverse effects were observed.

Conclusions

Although this study had an uncontrolled small group and a short observation period, our results suggest that etelcalcetide could be a promising agent for SHPT treatment.

Managing hyperparathyroidism in hemodialysis: role of etelcalcetide

Secondary hyperparathyroidism (SHPT) is common in patients receiving maintenance hemodialysis and is associated with adverse outcomes. Currently, SHPT is managed by reducing circulating levels of phosphate with oral binders and parathyroid hormone (PTH) with vitamin D analogs and/or the calcimimetic cinacalcet. Etelcalcetide, a novel calcimimetic administered intravenously (IV) at the end of a hemodialysis treatment session, effectively reduces PTH in clinical trials when given thrice weekly. Additional clinical effects include reductions in circulating levels of phosphate and FGF-23 and an improved profile of markers of bone turnover. However, despite being administered IV, etelcalcetide appears to be associated with rates of nausea and vomiting comparable to those of cinacalcet. Additionally, etelcalcetide, relative to placebo, causes hypocalcemia and prolonged electrocardiographic QT intervals, effects that must be considered when contemplating its use. Etelcalcetide likely has a role in treating hemodialysis patients with uncontrolled SHPT or with hypercalcemia or hyperphosphatemia receiving activated vitamin D compounds. However, its use should be at least partially constrained by consideration of the risk of hypocalcemia and resultant prolonged QT intervals in vulnerable patients. Because of its effectiveness as a PTH-reducing agent administered in the dialysis unit, etelcalcetide represents a potentially promising new therapeutic approach to the often vexing problem of SHPT in hemodialysis patients. However, whether its use is associated with changes in surrogate clinical end points, such as effects on rates of parathyroidectomy, fracture, vascular calcification, or mortality or on quality of life, remains to be studied.