ePHex: a phase 3, double-blind, placebo-controlled, randomized study to evaluate long-term efficacy and safety of Oxalobacter formigenes in patients with primary hyperoxaluria.

BACKGROUND: Primary hyperoxalurias (PHs) are rare genetic diseases that increase the endogenous level of oxalate, a waste metabolite excreted predominantly by the kidneys and also the gut. Treatments aim to improve oxalate excretion, or reduce oxalate generation, to prevent kidney function deterioration. Oxalobacter formigenes is an oxalate metabolizing bacterium. This Phase III, double-blind, placebo-controlled randomized trial investigated the effectiveness of orally administered Oxabact™, a lyophilized O. formigenes formulation, at reducing plasma oxalate levels in patients suffering from PH. METHODS: Subjects (≥ 2 years of age) with a diagnosis of PH and maintained but suboptimal kidney function (mean estimated glomerular filtration rate at baseline < 90 mL/min/1.73 m2) were eligible to participate. Subjects were randomized to receive Oxabact or placebo twice daily for 52 weeks. Change from baseline in plasma oxalate concentration at Week 52 was the primary study endpoint. RESULTS: Forty-three subjects were screened, 25 were recruited and one was discontinued. At Week 52, O. formigenes was established in the gut of subjects receiving Oxabact. Despite decreasing plasma oxalate level in subjects treated with Oxabact, and stable/increased levels with placebo, there was no significant difference between groups in the primary outcome (Least Squares mean estimate of treatment difference was - 3.80 µmol/L; 95% CI: - 7.83, 0.23; p-value = 0.064). Kidney function remained stable in both treatments. CONCLUSIONS: Oxabact treatment may have stabilized/reduced plasma oxalate versus a rise with placebo, but the difference over 12 months was not statistically significant (p = 0.06). A subtle effect observed with Oxabact suggests that O. formigenes may aid in preventing kidney stones. A higher resolution version of the Graphical abstract is available as Supplementary information.

Plasma oxalate and eGFR are correlated in primary hyperoxaluria patients with maintained kidney function-data from three placebo-controlled studies.

BACKGROUND: In patients with primary hyperoxaluria (PH), endogenous oxalate overproduction increases urinary oxalate excretion, leading to compromised kidney function and often kidney failure. Highly elevated plasma oxalate (Pox) is associated with systemic oxalate deposition in patients with PH and severe chronic kidney disease (CKD). The relationship between Pox and estimated glomerular filtration rate (eGFR) in patients with preserved kidney function, however, is not well established. Our analysis aimed to investigate a potential correlation between these parameters in PH patients from three randomized, placebo-controlled trials (studies OC3-DB-01, OC3-DB-02, and OC5-DB-01). METHODS: Baseline data from patients with a PH diagnosis (type 1, 2, or 3) and eGFR > 40 mL/min/1.73 m2 were analyzed for a correlation between eGFR and Pox using Spearman's rank and Pearson's correlation coefficients. Data were analyzed by individual study and additionally were pooled for Studies OC3-DB-02 and OC5-DB-01 in which the same Pox assay was used. RESULTS: A total of 106 patients were analyzed. A statistically significant inverse Spearman's correlation between eGFR and Pox was observed across all analyses; correlation coefficients were - 0.44 in study OC3-DB-01, - 0.55 in study OC3-DB-02, - 0.51 in study OC5-DB-01, and - 0.49 in the pooled studies (p < 0.0064). CONCLUSIONS: Baseline evaluations showed a moderate and statistically significant inverse correlation between eGFR and Pox in patients with PH already at early stages of CKD (stages 1-3b), demonstrating that a correlation is present before substantial loss in kidney function occurs.

A Decision-Analytic Model to Assess the Cost-Effectiveness of Etelcalcetide vs. Cinacalcet.

INTRODUCTION: Etelcalcetide is a novel intravenous calcimimetic for the treatment of secondary hyperparathyroidism (SHPT) in haemodialysis patients. The clinical efficacy and safety of etelcalcetide (in addition to phosphate binders and vitamin D and/or analogues [PB/VD]) was evaluated in three phase III studies, including two placebo-controlled trials and a head-to-head study versus the oral calcimimetic cinacalcet. OBJECTIVE: The objective of this study was to develop a decision-analytic model for economic evaluation of etelcalcetide compared with cinacalcet. METHODS: We developed a life-time Markov model including potential treatment effects on mortality, cardiovascular events, fractures, and subjects' persistence. Long-term efficacy of etelcalcetide was extrapolated from the reduction in parathyroid hormone (PTH) in the phase III trials and the available data from the outcomes study in cinacalcet (EVOLVE trial). Etelcalcetide was compared with cinacalcet, both in addition to PB/VD. We applied unit costs averaged from five European countries and a range of potential etelcalcetide pricing options assuming parity price to weekly use of cinacalcet and varying it by a 15 or 30% increase. RESULTS: Compared with cinacalcet, the incremental cost-effectiveness ratio of etelcalcetide was €1,355 per QALY, €24,521 per QALY, and €47,687 per QALY for the three prices explored. The results were robust across the probabilistic and deterministic sensitivity analyses. CONCLUSIONS: Our modelling approach enabled cost-utility assessment of the novel therapy for SHPT based on the observed and extrapolated data. This model can be used for local adaptations in the context of reimbursement assessment.

Effect of Etelcalcetide vs Cinacalcet on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: A Randomized Clinical Trial.

Importance: Secondary hyperparathyroidism contributes to extraskeletal calcification and is associated with all-cause and cardiovascular mortality. Control is suboptimal in the majority of patients receiving hemodialysis. An intravenously (IV) administered calcimimetic could improve adherence and reduce adverse gastrointestinal effects. Objective: To evaluate the relative efficacy and safety of the IV calcimimetic etelcalcetide and the oral calcimimetic cinacalcet. Design, Setting, and Participants: A randomized, double-blind, double-dummy active clinical trial was conducted comparing IV etelcalcetide vs oral placebo and oral cinacalcet vs IV placebo in 683 patients receiving hemodialysis with serum parathyroid hormone (PTH) concentrations higher than 500 pg/mL on active therapy at 164 sites in the United States, Canada, Europe, Russia, and New Zealand. Patients were enrolled from August 2013 to May 2014, with end of follow-up in January 2015. Interventions: Etelcalcetide intravenously and oral placebo (n = 340) or oral cinacalcet and IV placebo (n = 343) for 26 weeks. The IV study drug was administered 3 times weekly with hemodialysis; the oral study drug was administered daily. Main Outcomes and Measures: The primary efficacy end point was noninferiority of etelcalcetide at achieving more than a 30% reduction from baseline in mean predialysis PTH concentrations during weeks 20-27 (noninferiority margin, 12.0%). Secondary end points included superiority in achieving biochemical end points (>50% and >30% reduction in PTH) and self-reported nausea or vomiting. Results: The mean (SD) age of the trial participants was 54.7 (14.1) years and 56.2% were men. Etelcalcetide was noninferior to cinacalcet on the primary end point. The estimated difference in proportions of patients achieving reduction in PTH concentrations of more than 30% between the 198 of 343 patients (57.7%) randomized to receive cinacalcet and the 232 of 340 patients (68.2%) randomized to receive etelcalcetide was -10.5% (95% CI, -17.5% to -3.5%, P for noninferiority, <.001; P for superiority, .004). One hundred seventy-eight patients (52.4%) randomized to etelcalcetide achieved more than 50% reduction in PTH concentrations compared with 138 patients (40.2%) randomized to cinacalcet (P = .001; difference in proportions, 12.2%; 95% CI, 4.7% to 19.5%). The most common adverse effect was decreased blood calcium (68.9% vs 59.8%). Conclusions and Relevance: Among patients receiving hemodialysis with moderate to severe secondary hyperparathyroidism, the use of etelcalcetide was not inferior to cinacalcet in reducing serum PTH concentrations over 26 weeks; it also met superiority criteria. Further studies are needed to assess clinical outcomes as well as longer-term efficacy and safety. Trial Registration: clinicaltrials.gov Identifier: NCT1896232.

The clinical course of treated hyperparathyroidism among patients receiving hemodialysis and the effect of cinacalcet: the EVOLVE trial.

CONTEXT: The clinical course of secondary hyperparathyroidism (sHPT) in patients on hemodialysis is not well described, and the effect of the calcimimetic cinacalcet on disease progression is uncertain. OBJECTIVE: Our objective was to describe 1) the clinical course of sHPT in patients treated with phosphate binders and/or vitamin D sterols and 2) the impact of cinacalcet on the occurrence of severe unremitting HPT, defined by the persistence of markedly elevated PTH concentrations together with hypercalcemia or parathyroidectomy (PTX). DESIGN AND SETTING: This was a randomized, double-blind, placebo-controlled, global, multicenter clinical trial. PATIENTS: Of 5755 patients screened with moderate to severe sHPT, 3883 patients on hemodialysis were included in the trial. MAIN OUTCOME MEASURES: Outcomes included PTX; severe, unremitting HPT; and use of commercial cinacalcet (a protocol violation). INTERVENTION: Intervention was cinacalcet (30-180 mg daily) or placebo for up to 64 months. RESULTS: In the 1935 patients randomized to placebo, 278 patients (14%) underwent PTX (median PTH 1872 pg/mL within the previous 12 weeks from surgery). Age, sex, geographic region, co-morbidity, calcium-containing phosphate binder use, and baseline serum calcium, phosphorus, and PTH concentrations were associated with PTX. Commercial cinacalcet was started in 443 (23%) patients (median PTH 1108 pg/mL before treatment began). Severe unremitting HPT developed in 470 patients (24%). In a multivariable Cox model, the relative hazard (comparing patients randomized to cinacalcet versus placebo) of severe unremitting HPT was 0.31 (95% confidence interval = 0.26-0.37). The relative hazard differed little when adjusted by baseline clinical characteristics. CONCLUSIONS: Severe unremitting HPT develops frequently in patients on hemodialysis despite conventional therapy, and cinacalcet substantially reduces its occurrence.

The ADVANCE study: a randomized study to evaluate the effects of cinacalcet plus low-dose vitamin D on vascular calcification in patients on hemodialysis.

BACKGROUND: This prospective, randomized, controlled trial compared the progression of vascular and cardiac valve calcification in 360 prevalent adult hemodialysis patients with secondary hyperparathyroidism treated with either cinacalcet plus low-dose vitamin D sterols or flexible doses of vitamin D sterols alone. METHODS: Eligible subjects were on hemodialysis for ≥ 3 months with parathyroid hormone (PTH) > 300 pg/mL or PTH 150-300 pg/mL with calcium-phosphorus product > 50 mg(2)/dL(2) while receiving vitamin D. All subjects received calcium-based phosphate binders. Coronary artery calcification (CAC) and aorta and cardiac valve calcium scores were determined both by Agatston and volume scoring using multi-detector computed tomography. Subjects with Agatston CAC scores ≥ 30 were randomized to cinacalcet (30- 180 mg/day) plus low-dose calcitriol or vitamin D analog (≤ 2 µg paricalcitol equivalent/dialysis), or flexible vitamin D therapy. The primary end point was percentage change in Agatston CAC score from baseline to Week 52. RESULTS: Median (P10, P90) Agatston CAC scores increased 24% (-22%, 119%) in the cinacalcet group and 31% (-9%, 179%) in the flexible vitamin D group (P = 0.073). Corresponding changes in volume CAC scores were 22% (-12%, 105%) and 30% (-6%, 133%; P = 0.009). Increases in calcification scores were consistently less in the aorta, aortic valve and mitral valve among subjects treated with cinacalcet plus low-dose vitamin D sterols, and the differences between groups were significant at the aortic valve. CONCLUSIONS: In hemodialysis patients with moderate to severe secondary hyperparathyroidism, cinacalcet plus low-dose vitamin D sterols may attenuate vascular and cardiac valve calcification.

Effectiveness of cinacalcet in patients with recurrent/persistent secondary hyperparathyroidism following parathyroidectomy: results of the ECHO study.

BACKGROUND: Progressive secondary hyperparathyroidism (sHPT) is characterized by parathyroid gland hyperplasia which may ultimately require parathyroidectomy (PTX). Although PTX is generally a successful treatment for those patients subjected to surgery, a significant proportion develops recurrent sHPT following PTX. ECHO was a pan-European observational study which evaluated the achievement of KDOQI(TM) treatment targets with cinacalcet use in patients on dialysis. Previously published results showed that cinacalcet plus flexible vitamin D therapy lowered serum PTH, phosphorus and calcium in the clinical practice with similar efficacy as seen in phase III trials. METHODS: This subgroup analysis of ECHO describes the real-world cinacalcet treatment effect in patients with recurrent or persistent sHPT after PTX (n = 153) compared to sHPT patients without prior history of PTX (n = 1696). RESULTS: Both groups of patients had substantially elevated serum PTH with comparable sHPT severity at baseline. After 12 months of cinacalcet treatment, 20.3% (26/128) of patients with prior PTX and 18.2% (253/1388) of patients without prior PTX achieved serum PTH and Ca × P values within the recommended KDOQI(TM) target ranges. CONCLUSIONS: Our data support the successful use of cinacalcet in patients with recurrent/persistent sHPT after PTX.

Study design and subject baseline characteristics in the ADVANCE Study: effects of cinacalcet on vascular calcification in haemodialysis patients.

BACKGROUND: The ADVANCE (A Randomized Study to Evaluate the Effects of Cinacalcet plus Low-Dose Vitamin D on Vascular Calcification in Subjects with Chronic Kidney Disease Receiving Haemodialysis) Study objective is to assess the effect of cinacalcet plus low-dose active vitamin D versus flexible dosing of active vitamin D on progression of coronary artery calcification (CAC) in haemodialysis patients. We report the ADVANCE Study design and baseline subject characteristics. METHODS: ADVANCE is a multinational, multicentre, randomized, open-label study. Adult haemodialysis patients with moderate to severe secondary hyperparathyroidism (intact parathyroid hormone [iPTH] >300 pg/mL or bio-intact PTH >160 pg/mL) and baseline CAC score >or=30 were stratified by CAC score (>or=30-399, >or=400-999, >or=1000) and randomized in a 1:1 ratio to cinacalcet (30-180 mg/day) plus low-dose active vitamin D (cinacalcet group) or flexible dosing of active vitamin D alone (control). The study had three phases: screening, 20-week dose titration and 32-week follow-up. CAC scores obtained by cardiac computed tomography were determined at screening and weeks 28 and 52. The primary end point was percentage change in CAC score from baseline to Week 52. RESULTS: Subjects (n = 360) were randomized to cinacalcet or control. Mean age was 61.5 years, 43% were women, and median dialysis vintage was 36.7 months (range, 2.7-351.5 months). The baseline geometric mean CAC score by the Agatston method was 548.7 (95% confidence interval, 480.5-626.6). Baseline CAC score was independently associated with age, sex, dialysis vintage, diabetes and iPTH. Subjects also had extensive aortic and valvular calcification at baseline. CONCLUSIONS: Subjects enrolled in ADVANCE have extensive CAC at baseline. The ADVANCE Study should help determine whether cinacalcet attenuates progression of vascular calcification.