Performance of hemodialysis with novel medium cut-off dialyzers.

Background: Compared to high-flux dialysis membranes, novel medium cut-off (MCO) membranes show greater permeability for larger middle molecules. Methods: In two prospective, open-label, controlled, randomized, crossover pilot studies, 39 prevalent hemodialysis (HD) patients were studied in four dialysis treatments as follows: study 1, three MCO prototype dialyzers (AA, BB and CC with increasing permeability) and one high-flux dialyzer in HD; and study 2, two MCO prototype dialyzers (AA and BB) in HD and high-flux dialyzers in HD and hemodiafiltration (HDF). Primary outcome was lambda free light chain (λFLC) overall clearance. Secondary outcomes included overall clearances and pre-to-post-reduction ratios of middle and small molecules, and safety of MCO HD treatments. Results: MCO HD provided greater λFLC overall clearance [least square mean (standard error)] as follows: study 1: MCO AA 8.5 (0.54), MCO BB 11.3 (0.51), MCO CC 15.0 (0.53) versus high-flux HD 3.6 (0.51) mL/min; study 2: MCO AA 10.0 (0.58), MCO BB 12.5 (0.57) versus high-flux HD 4.4 (0.57) and HDF 6.2 (0.58) mL/min. Differences between MCO and high-flux dialyzers were consistently significant in mixed model analysis (each P < 0.001). Reduction ratios of λFLC were greater for MCO. Clearances of α1-microglobulin, complement factor D, kappa FLC (κFLC) and myoglobin were generally greater with MCO than with high-flux HD and similar to or greater than clearances with HDF. Albumin loss was moderate with MCO, but greater than with high-flux HD and HDF. Conclusions: MCO HD removes a wide range of middle molecules more effectively than high-flux HD and even exceeds the performance of high-volume HDF for large solutes, particularly λFLC.

Clinical safety and performance of VIVIA: a novel home hemodialysis system.

Background: The VIVIA Hemodialysis System (Baxter Healthcare Corporation, Deerfield, IL, USA) was designed for patient use at home to reduce the burden of treatment and improve patient safety. It has unique features including extended use of the dialyzer and blood set through in situ hot-water disinfection between treatments; generation of on-line infusible-quality dialysate for automated priming, rinseback and hemodynamic support during hypotension and a fully integrated access disconnect sensor. Methods: The safety and performance of VIVIA were assessed in two clinical studies. A first-in-man study was a prospective, single-arm study that involved 22 prevalent hemodialysis (HD) patients who were treated for ∼4 h, four times a week, for 10 weeks. A second clinical study was a prospective, single-arm study (6-8 h of dialysis treatment at night three times a week) that involved 17 prevalent patients treated for 6 weeks. Results: There were 1114 treatments from the two studies (first-in-man study, 816; extended duration study, 298). Adverse events (AEs) were similar in the two studies to those expected for prevalent HD patients. No deaths and no device-related serious AEs occurred. Adequacy of dialysis ( Kt / V ) urea in both clinical trials was well above the clinical guidelines. VIVIA performed ultrafiltration accurately as prescribed in the two studies. The majority of patients achieved 10 or more uses of the dialyzer. Endotoxin levels and bacterial dialysate sampling met infusible-quality dialysate standards. Conclusion: These results confirm the safety and expected performance of VIVIA.

Efficacy and initial dose determination of paricalcitol for treatment of secondary hyperparathyroidism in Chinese subjects.

AIM: Prevalence of secondary hyperparathyroidism (SHPT), a renal disease complication, is increasing in China. Available therapies may not optimally control SHPT, particularly in patients with hypercalcemia, hyperphosphatemia, and parathyroid hyperplasia. This study examined efficacy and safety of two dosing regimens of selective vitamin D receptor activator paricalcitol. MATERIALS AND METHODS: Subjects with SHPT (n = 216) undergoing hemodialysis were treated with paricalcitol i.v. for 12 weeks. One group was treated according to the EU paricalcitol package insert (PI) (initial µg dose based on iPTH/80), and the other was treated according to the US PI (initial dose of 0.04 µg/kg). Dose titration was based on iPTH and serum calcium (Ca) and phosphorus (P) levels. RESULTS: The primary endpoint of two consecutive ≥ 30% iPTH decreases was achieved by 88.6% and 55.9% of subjects in the EU and US PI groups, respectively. Noninferiority of the EU PI group vs. the US PI group was demonstrated (lower bound of the 1-sided 97.5% CI = 21.3%). Superiority of the EU PI group was shown (lower limit > 0%) and confirmed by Fisher's exact test (p < 0.001); both groups showed similar achievement of recommended KDIGO iPTH levels. Ca and P levels were relatively constant. CONCLUSION: Both EU and US PI paricalcitol dosing strategies effectively reduced iPTH levels in Chinese subjects with SHPT, with minimal impact on Ca and P levels.

Effects of paricalcitol on calcium and phosphate metabolism and markers of bone health in patients with diabetic nephropathy: results of the VITAL study.

BACKGROUND: Chronic kidney disease (CKD) is associated with elevations in serum phosphate, calcium-phosphorus product and bone-specific alkaline phosphatase (BAP), with attendant risks of cardiovascular and bone disorders. Active vitamin D can suppress parathyroid hormone (PTH), but may raise serum calcium and phosphate concentrations. Paricalcitol, a selective vitamin D activator, suppressed PTH in CKD patients (stages 3 and 4) with secondary hyperparathyroidism (SHPT) with minimal changes in calcium and phosphate metabolism. METHODS: The VITAL study enrolled patients with CKD stages 2-4. We examined the effect and relationship of paricalcitol to calcium and phosphate metabolism and bone markers in a post hoc analysis of VITAL. The study comprised patients with diabetic nephropathy enrolled in a double-blind, placebo-controlled, randomized trial of paricalcitol (1 or 2 µg/day). Urinary and serum calcium and phosphate, serum BAP, and intact PTH (iPTH) concentrations were measured throughout the study. RESULTS: Baseline demographics and calcium, phosphate, PTH (49% with iPTH <70 pg/mL), and BAP concentrations were similar between groups. A transient, modest yet significant increase in phosphate was observed for paricalcitol 2 µg/day (+0.29 mg/dL; P < 0.001). Dose-dependent increases in serum and urinary calcium were observed; however, there were few cases of hypercalcemia: one in the 1-µg/day group (1.1%) and three in the 2-µg/day group (3.2%). Significant reductions in BAP were observed that persisted for 60 days after paricalcitol discontinuation (P < 0.001 for combined paricalcitol groups versus placebo). Paricalcitol dose-dependent reductions in iPTH were observed. Paricalcitol in CKD patients (±SHPT) was associated with modest increases in calcium and phosphate. CONCLUSION: Paricalcitol reduces BAP levels, which may be beneficial for reducing vascular calcification. TRIAL REGISTRATION: Trial is registered with ClinicalTrials.gov, number NCT00421733.

Paricalcitol versus cinacalcet plus low-dose vitamin D therapy for the treatment of secondary hyperparathyroidism in patients receiving haemodialysis: results of the IMPACT SHPT study.

BACKGROUND: Optimal treatment for secondary hyperparathyroidism (SHPT) has not been defined. The IMPACT SHPT (ClinicalTrials.gov identifier: NCT00977080) study assessed whether dose-titrated paricalcitol plus supplemental cinacalcet only for hypercalcaemia is superior to cinacalcet plus low-dose vitamin D in controlling intact parathyroid hormone (iPTH) levels in patients with SHPT on haemodialysis. METHODS: In this 28-week, multicentre, open-label Phase 4 study, participants were randomly selected to receive paricalcitol or cinacalcet plus low-dose vitamin D. Randomization and analyses were stratified by mode of paricalcitol administration [intravenous (IV) or oral]. The primary efficacy end point was the proportion of subjects who achieved a mean iPTH value of 150-300 pg/mL during Weeks 21-28. RESULTS: Of 272 subjects randomized, 268 received one or more dose of study drug; 101 in the IV and 110 in the oral stratum with two or more values during Weeks 21-28 were included in the primary analysis. In the IV stratum, 57.7% of subjects in the paricalcitol versus 32.7% in the cinacalcet group (P = 0.016) achieved the primary end point. In the oral stratum, the corresponding proportions of subjects were 54.4% for paricalcitol and 43.4% for cinacalcet (P = 0.260). Cochran-Mantel-Haenszel analysis, controlling for stratum, revealed overall superiority of paricalcitol (56.0%) over cinacalcet (38.2%; P = 0.010) in achieving iPTH 150-300 pg/mL during Weeks 21-28. Hypercalcaemia occurred in 4 (7.7%) and 0 (0%) of paricalcitol-treated subjects in the IV and oral strata, respectively. Hypocalcaemia occurred in 46.9% and 54.7% of cinacalcet-treated subjects in the IV and oral strata, respectively. CONCLUSION: Paricalcitol versus cinacalcet plus low-dose vitamin D provided superior control of iPTH, with low incidence of hypercalcaemia.

Paricalcitol versus cinacalcet plus low-dose vitamin D for the treatment of secondary hyperparathyroidism in patients receiving haemodialysis: study design and baseline characteristics of the IMPACT SHPT study.

BACKGROUND: Paricalcitol and cinacalcet are common therapies for patients on haemodialysis with secondary hyperparathyroidism (SHPT). We conducted a multi-centre study in 12 countries to compare the safety and efficacy of paricalcitol and cinacalcet for the treatment of SHPT. METHODS: Patients aged ≥18 years with Stage 5 chronic kidney disease receiving maintenance haemodialysis and with intact parathyroid hormone (iPTH) 300-800 pg/mL, calcium 8.4-10.0 mg/dL (2.09-2.49 mmol/L) and phosphorus ≤6.5 mg/dL (2.09 mmol/L) were randomized within two strata defined by the mode of paricalcitol administration to treatment with paricalcitol- (intra-venous, US and Russian sites, IV stratum; oral, non-US and non-Russian sites, oral stratum) or cinacalcet-centred therapy. The primary endpoint is the proportion of patients in each treatment group who achieve a mean iPTH value of 150-300 pg/mL during Weeks 21-28 of treatment. Assuming efficacy response rates of 36 and 66% for cinacalcet and paricalcitol, respectively, and a 20% discontinuation rate, 124 subjects in each stratum were estimated to provide 81% power to detect a 30% absolute difference in the primary endpoint. RESULTS: Of 746 patients screened, 272 (mean age, 63 years; mean iPTH, 509 pg/mL) were randomized. Mean duration of haemodialysis at baseline was 3.7 years. Comorbidities included hypertension (90.4%), Type 2 diabetes (40.4%), congestive heart failure (17.3%), coronary artery disease (34.6%) and gastrointestinal disorders (75%). CONCLUSIONS: The study participants are representative of a multinational cohort of patients on haemodialysis with elevated iPTH. The study results will provide valuable information on the best available treatment of SHPT in patients on haemodialysis.

Selective vitamin D receptor activation with paricalcitol for reduction of albuminuria in patients with type 2 diabetes (VITAL study): a randomised controlled trial.

BACKGROUND: Despite treatment with renin­angiotensin­aldosterone system (RAAS) inhibitors, patients with diabetes have increased risk of progressive renal failure that correlates with albuminuria. We aimed to assess whether paricalcitol could be used to reduce albuminuria in patients with diabetic nephropathy. METHODS: In this multinational, placebo-controlled, double-blind trial, we enrolled patients with type 2 diabetes and albuminuria who were receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Patients were assigned (1:1:1) by computer-generated randomisation sequence to receive 24 weeks' treatment with placebo,1 µg/day paricalcitol, or 2 µg/day paricalcitol. The primary endpoint was the percentage change in geometric mean urinary albumin-to-creatinine ratio (UACR) from baseline to last measurement during treatment for the combined paricalcitol groups versus the placebo group. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00421733. FINDINGS: Between February, 2007, and October, 2008, 281 patients were enrolled and assigned to receive placebo(n=93), 1 µg paricalcitol (n=93), or 2 µg paricalcitol (n=95); 88 patients on placebo, 92 on 1 µg paricalcitol, and 92 on2 µg paricalcitol received at least one dose of study drug, and had UACR data at baseline and at least one timepoint during treatment, and so were included in the primary analysis. Change in UACR was: ­3% (from 61 to 60 mg/mmol;95% CI ­16 to 13) in the placebo group; ­16% (from 62 to 51 mg/mmol; ­24 to ­9) in the combined paricalcitol groups, with a between-group difference versus placebo of ­15% (95% CI ­28 to 1; p=0.071); ­14% (from 63 to 54 mg/mmol; ­24 to ­1) in the 1 µg paricalcitol group, with a between-group difference versus placebo of ­11%(95% CI ­27 to 8; p=0.23); and ­20% (from 61 to 49 mg/mmol; ­30 to ­8) in the 2 µg paricalcitol group, with a between-group difference versus placebo of ­18% (95% CI ­32 to 0; p=0.053). Patients on 2 µg paricalcitol showed a nearly, sustained reduction in UACR, ranging from ­18% to ­28% (p=0.014 vs placebo). Incidence of hypercalcaemia,adverse events, and serious adverse events was similar between groups receiving paricalcitol versus placebo. INTERPRETATION: Addition of 2 µg/day paricalcitol to RAAS inhibition safely lowers residual albuminuria in patients with diabetic nephropathy, and could be a novel approach to lower residual renal risk in diabetes. FUNDING: Abbott.

Differential effects of paricalcitol and calcitriol on intestinal calcium absorption in hemodialysis patients.

BACKGROUND/AIMS: Increased parathyroid activity associated with chronic kidney disease is often managed with calcitriol, which can elevate serum calcium (Ca) by increasing bone resorption and intestinal absorption, whereas paricalcitol promotes less bone resorption. This study compared intestinal Ca absorption in hemodialysis patients treated with calcitriol versus paricalcitol (dose ratio 1:3). METHODS: Patients (n = 22) aged > or =20 years, on maintenance hemodialysis for > or =2 months with intact parathyroid hormone (iPTH) levels of >200 pg/ml were enrolled in a single-center, double-blind, active-controlled, randomized, crossover trial. Mean fractional intestinal Ca absorption (+/-SE) was measured by the single-tracer method ((42)Ca) and evaluated with an analysis of variance crossover model. RESULTS: Mean fractional intestinal Ca absorption was significantly lower after paricalcitol (0.135 +/- 0.006) versus calcitriol treatment (0.158 +/- 0.006, p = 0.022), a 0.023 difference in absolute Ca absorption fraction. Overall Ca absorption was low in the study population, indicating that regulation of Ca absorption may be dysfunctional. There were no significant differences in serum PTH, Ca, phosphorus (P), or Ca x P. CONCLUSION: Overall, paricalcitol-treated patients absorbed approximately 14% less Ca compared with calcitriol-treated patients with similar effects on PTH. In hemodialysis patients, paricalcitol may provide a benefit by lowering the Ca available for removal by dialysis and/or for deposit in bone or soft tissues.

Intravenous paricalcitol for treatment of secondary hyperparathyroidism in children on hemodialysis.

BACKGROUND: Secondary hyperparathyroidism is a common complication in children receiving hemodialysis. Active vitamin D is an effective therapy, but its use is often limited by hypercalcemia and increased calcium x phosphorus (Ca x P) product. Paricalcitol, a selective vitamin D receptor activator, causes less sustained hypercalcemia and increase in Ca x P product than calcitriol and has been used effectively in adult hemodialysis patients. STUDY DESIGN: Double blind, placebo-controlled. SETTING & PARTICIPANTS: Hemodialysis units and pediatric subjects receiving hemodialysis. INTERVENTION: After a washout period of 2 to 6 weeks, 29 subjects aged 5 to 19 years received either paricalcitol or placebo for up to 12 weeks (0.04 mug/kg if initial intact parathyroid hormone [iPTH] level < 500 pg/mL [ng/L]; 0.08 mug/kg if initial iPTH level > 500 pg/mL [ng/L]). The dose was increased by 0.04 mug/kg every 2 weeks until there was a 30% decrease in iPTH level from baseline or calcium level greater than 11 mg/dL (>2.74 mmol/L) or Ca x P product greater than 75 mg(2)/dL(2) (>6.04 mmol(2)/L(2)). OUTCOMES & MEASUREMENTS: Two consecutive 30% decreases from baseline in iPTH levels and safety of paricalcitol, including hypercalcemia and increase in Ca x P product. RESULTS: 60% of the paricalcitol group had 2 consecutive 30% decreases from baseline iPTH levels compared with 21% in the placebo group (P = 0.06). The paricalcitol group had a mean decrease in iPTH level of 164 pg/mL (ng/L), whereas the placebo group had a mean increase of 238 pg/mL (ng/L; P = 0.03). There was no difference from baseline to final visit in calcium, phosphorus, or Ca x P product values in either group. LIMITATIONS: Low power to detect differences in safety between groups and a short-term study. CONCLUSION: Paricalcitol decreased iPTH levels in children receiving hemodialysis with no significant changes in serum calcium, phosphorus, or Ca x P product values during the course of the study.

Paricalcitol-treated patients experience improved hospitalization outcomes compared with calcitriol-treated patients in real-world clinical settings.

BACKGROUND: Abnormalities of serum calcium, phosphorous and intact parathyroid hormone (PTH) are associated with morbidity and mortality in haemodialysis patients. Pharmacologic parenteral vitamin D administration is used to correct these abnormalities; however, the relationship between vitamin D therapies and hospitalizations has never been addressed. METHODS: Healthcare data from January 1999 to November 2001 were analysed for 11,443 adult haemodialysis patients who received at least 10 doses of vitamin D therapy. Multivariate models were used to evaluate the effects of vitamin D therapy on: (i) total number of hospitalizations, (ii) total number of hospital days and (iii) risk of first hospitalization after initiation of vitamin D therapy. RESULTS: When compared with the calcitriol group, the paricalcitol group had a lower risk of first all-cause hospitalization (14% less likely, P<0.0001), fewer hospitalizations per year (0.642 fewer, P<0.001) and fewer hospital days per year (6.84 fewer, P<0.001). In the paricalcitol and calcitriol groups, respectively, 5.6 and 41.3% patients switched to another vitamin D compound. For those patients who started and remained on the same vitamin D product, paricalcitol-treated patients experienced 0.846 fewer hospitalizations per year and 9.17 fewer hospital days per year, P<0.001 for both. The paricalcitol group also had a lower risk of first PTH-related hospitalizations, fewer PTH-related annual hospitalizations and fewer days per year. CONCLUSION: Paricalcitol-treated patients experienced fewer hospitalizations and hospital days per year when compared with calcitriol-treated patients. Initiating vitamin D therapy with paricalcitol may result in overall savings of approximately 7600-11,000 US dollars per patient per year. A randomized, controlled, blinded study would be valuable in confirming and understanding these results.

Paricalcitol versus calcitriol in the treatment of secondary hyperparathyroidism.

BACKGROUND: Management of secondary hyperparathyroidism has included the use of active vitamin D or vitamin D analogs for the suppression of parathyroid hormone (PTH) secretion. Although, these agents are effective, therapy is frequently limited by hypercalcemia, hyperphosphatemia, and/or elevations in the calcium-phosphorus (Ca x P) product. In clinical studies, paricalcitol was shown to be effective at reducing PTH concentrations without causing significant hypercalcemia or hyperphosphatemia as compared to placebo. A comparative study was undertaken in order to determine whether paricalcitol provides a therapeutic advantage to calcitriol. METHODS: A double-blind, randomized, multicenter study comparing the safety and effectiveness of intravenous paricalcitol and calcitriol in suppressing PTH concentrations in hemodialysis patients was performed. A total of 263 randomized patients were enrolled at domestic and international sites. Following the baseline period, patients with serum Ca x P < 75, and a PTH level > or =300 pg/mL were randomly assigned to receive either paricalcitol or calcitriol in a dose-escalating fashion for up to 32 weeks. Dose adjustments were based on laboratory results for PTH, calcium, and Ca x P. The primary end point was the greater than 50% reduction in baseline PTH. Secondary end points were the occurrence of hypercalcemia and elevated Ca x P product. RESULTS: Paricalcitol-treated patients achieved a > or =50% reduction from baseline PTH significantly faster than did the calcitriol-treated patients (P = 0.025) and achieved a mean reduction of PTH into a desired therapeutic range (100 to 300 pg/mL) at approximately week 18, whereas the calcitriol-treated patients, as a group, were unable to achieve this range. Moreover, paricalcitol-treated patients had significantly fewer sustained episodes of hypercalcemia and/or increased Ca x P product than calcitriol patients (P = 0.008). CONCLUSION: Paricalcitol treatment reduced PTH concentrations more rapidly with fewer sustained episodes of hypercalcemia and increased Ca x P product than calcitriol therapy.