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Background/aims: Vitamin D insufficiency and secondary hyperparathyroidism (SHPT) are associated with increased morbidity and mortality in chronic kidney disease (CKD) and are poorly addressed by current treatments. The present clinical studies evaluated extended-release (ER) calcifediol, a novel vitamin D prohormone repletion therapy designed to gradually correct low serum total 25-hydroxyvitamin D, improve SHPT control and minimize the induction of CYP24A1 and FGF23.Methods: Two identical multicenter, randomized, double-blind, placebo-controlled studies enrolled subjects from 89 US sites. A total of 429 subjects, balanced between studies, with stage 3 or 4 CKD, SHPT and vitamin D insufficiency were randomized 2:1 to receive oral ER calcifediol (30 or 60 µg) or placebo once daily at bedtime for 26 weeks. Most subjects (354 or 83%) completed dosing, and 298 (69%) entered a subsequent open-label extension study wherein ER calcifediol was administered without interruption for another 26 weeks.Results: ER calcifediol normalized serum total 25-hydroxyvitamin D concentrations (>30 ng/ml) in >95% of per-protocol subjects and reduced plasma intact parathyroid hormone (iPTH) by at least 10% in 72%. The proportion of subjects receiving ER calcifediol who achieved iPTH reductions of ≥30% increased progressively with treatment duration, reaching 22, 40 and 50% at 12, 26 and 52 weeks, respectively. iPTH lowering with ER calcifediol was independent of CKD stage and significantly greater than with placebo. ER calcifediol had inconsequential impact on serum calcium, phosphorus, FGF23 and adverse events.Conclusion: Oral ER calcifediol is safe and effective in treating SHPT and vitamin D insufficiency in CKD. [ABSTRACT FROM AUTHOR]

Background/Aims: Vitamin D insufficiency drives secondary hyperparathyroidism (SHPT) and is associated with increased cardiovascular mortality in patients with chronic kidney disease (CKD). SHPT is poorly addressed by current vitamin D repletion options. The present study evaluated a novel investigational vitamin D repletion therapy: a modified-release (MR) formulation of calcifediol designed to raise serum 25-hydroxyvitamin D in a gradual manner to minimize the induction of CYP24 and, thereby, improve the SHPT control. Methods: This randomized, double-blind, placebo-controlled trial evaluated MR calcifediol in CKD subjects (n = 78) with plasma intact parathyroid hormone (iPTH) >70 pg/ml and serum total 25-hydroxyvitamin D <30 ng/ml. Subjects received daily treatment for six weeks with oral MR calcifediol (30, 60 or 90 µg) or a placebo. Results: More than 90% of subjects treated with MR calcifediol achieved serum 25-hydroxyvitamin D levels ≥30 ng/ml versus 3% of subjects treated with placebo (p < 0.0001). Mean plasma iPTH decreased from baseline (140.3 pg/ml) by 20.9 ± 6.2% (SE), 32.8 ± 5.7 and 39.3 ± 4.3% in the 30, 60 and 90 µg dose groups, respectively, and increased 17.2 ± 7.8% in the pooled placebo group (p < 0.005). No clinically significant safety concerns arose during MR calcifediol treatment. Conclusion: Oral MR calcifediol appears safe and highly effective in treating SHPT associated with vitamin D insufficiency in CKD. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/aims: Vitamin D insufficiency drives secondary hyperparathyroidism (SHPT) and is associated with increased cardiovascular mortality in patients with chronic kidney disease (CKD). SHPT is poorly addressed by current vitamin D repletion options. The present study evaluated a novel investigational vitamin D repletion therapy: a modified-release (MR) formulation of calcifediol designed to raise serum 25-hydroxyvitamin D in a gradual manner to minimize the induction of CYP24 and, thereby, improve the SHPT control.Methods: This randomized, double-blind, placebo-controlled trial evaluated MR calcifediol in CKD subjects (n = 78) with plasma intact parathyroid hormone (iPTH) >70 pg/ml and serum total 25-hydroxyvitamin D <30 ng/ml. Subjects received daily treatment for six weeks with oral MR calcifediol (30, 60 or 90 µg) or a placebo.Results: More than 90% of subjects treated with MR calcifediol achieved serum 25-hydroxyvitamin D levels ≥30 ng/ml versus 3% of subjects treated with placebo (p < 0.0001). Mean plasma iPTH decreased from baseline (140.3 pg/ml) by 20.9 ± 6.2% (SE), 32.8 ± 5.7 and 39.3 ± 4.3% in the 30, 60 and 90 µg dose groups, respectively, and increased 17.2 ± 7.8% in the pooled placebo group (p < 0.005). No clinically significant safety concerns arose during MR calcifediol treatment.Conclusion: Oral MR calcifediol appears safe and highly effective in treating SHPT associated with vitamin D insufficiency in CKD. [ABSTRACT FROM AUTHOR]

Background/Aims: Secondary hyperparathyroidism is a common complication of chronic kidney disease, resulting from inactivation of vitamin D receptor signaling and phosphate retention. Selective activation of vitamin D receptors with intravenous paricalcitol significantly reduced parathyroid hormone (PTH) levels with no significant hypercalcemia or hyperphosphatemia in predialysis and hemodialysis (HD) patients. This study investigates the effects of oral paricalcitol to reduce PTH in patients receiving chronic HD and peritoneal dialysis (PD). Methods: Eighty-eight patients were randomized in double-blind fashion to receive paricalcitol or placebo for 12 weeks. The dose of the study drug was adjusted weekly using the previous week’s intact PTH (iPTH) level as well as calcium and Ca × P product levels. The primary end points were efficacy (two consecutive iPTH decreases of ≥30%) and safety (two consecutive calcium measurements >11.0 mg/dl). Markers of biochemical bone activity were followed. Results: Demographic characteristics were similar between treatment groups. The mean paricalcitol doses (three times a week) over the entire treatment period for subjects with baseline iPTH ≤500 pg/ml and iPTH >500 pg/ml were 3.9 and 7.6 μg, respectively. A statistically significant decrease in iPTH was seen after week 1, with a mean 30% reduction occurring by week 3. A significantly greater proportion of both HD and PD paricalcitol subjects [83% (33/40) and 100% (18/18), respectively] achieved two consecutive ≥30% decreases in iPTH. The treatment groups were not statistically different in regard to the hypercalcemia safety end point. Phosphate binder use and mean serum phosphorus levels were not different between the treatment groups. The markers of bone activity improved in the treated subjects and worsened in those on placebo. Conclusion: Paricalcitol provides a rapid and sustained reduction of PTH in both HD and PD patients with minimal effect on serum calcium and phosphorus and no significant difference in adverse events as compared with placebo. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Intermittent dosing of calcitriol for secondary hyperparathyroidism (SHPT) has been associated with greater parathyroid hormone (PTH) reduction with fewer calcemic and phosphatemic effects than daily (QD) dosing. Methods: Secondary analyses of three randomized, double-blind, placebo-controlled multicenter studies in stage 3 and 4 chronic kidney disease (CKD) patients with SHPT were performed to compare three times per week (TIW) with QD dosing of paricalcitol. The pharmacokinetics of TIW and QD dosing of paricalcitol capsules were assessed in a separate group of healthy subjects. Results: Pharmacokinetics revealed similar steady state paricalcitol exposure between dosing regimens. In CKD patients, baseline data were similar between the TIW studies (n = 72, paricalcitol; n = 73, placebo) and QD studies (n = 35, paricalcitol; n = 40, placebo). Both dosing regimens resulted in similar efficacy (91%) for the primary end point of two consecutive ≥30% decreases in intact PTH from baseline, but the QD regimen resulted in a greater percent reduction in intact PTH from baseline. The chances for developing increased serum calcium and phosphorus levels or Ca × P product were similar between paricalcitol and placebo groups for both treatment regimens. Furthermore, no difference in the risk for these elevations was detected between the TIW and QD regimens. Conclusions: QD dosing of paricalcitol capsules is as efficacious as TIW dosing in achieving the primary end point (2 consecutive ≥30% reductions in PTH) in stage 3 and 4 CKD patients with SHPT. Moreover, the QD regimen had no significant effect on hypercalcemia, hyperphosphatemia or Ca × P product as compared with placebo or intermittent dosing. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

1. Iron-deficiency anaemia, a complication of end-stage renal disease (ESRD), is often treated with parenteral iron therapies that have been shown to produce dose-limiting hypotension in patients. ABT-870 (iron-(III)-hydroxide-oligosaccharide) is comprised of elemental iron complexed with oligosaccharide, a composition that we hypothesised would allow the hypotensive effects of parenteral iron therapy to be overcome, thus allowing a rapid rate of infusion to be well tolerated. 2. Mean arterial pressure (MAP) and heart rate (HR) were monitored in anaesthetized dogs following the infusion of ABT-870 and iron sucrose administered at doses of 7.1 and 21.3 mg/kg using a rapid 30 s infusion. ABT-870 and iron sucrose were also monitored at doses of 7.1, 21.3 and 50 mg/kg administered over a 10 min period. Sodium ferric gluconate complex (SFGC) was administered in an identical fashion at doses of 12.5 and 31.2 mg/kg. 3. A 30 s rapid infusion of ABT-870 at doses of 7.1 and 14.3 mg/kg or a 10 min infusion of ABT-870 at doses of 7.1 and 21.3 mg/kg produced little effect on MAP and HR. Infusion of the highest dose of ABT-870 (50 mg/kg) produced no consistent hypotension, but did produce an increase in HR (maximal increase 35 ± 9 b.p.m.), an effect that lasted only 15 min. A 30 s rapid infusion of iron sucrose at 7.1 mg/kg produced modest increases in MAP and HR (5 ± 1 mmHg and 5 ± 2 b.p.m., respectively). However, rapid infusion of iron sucrose at 14.3 mg/kg produced hypotension (to −8 ± 1 mmHg below baseline) and exerted variable, biphasic effects on HR ranging from −16 to +50 b.p.m. Although 10 min infusion of iron sucrose at 7.1 mg/kg exerted little effect on MAP and HR, at doses of 21.3 and 50 mg/kg iron sucrose elicited a profound dose-dependent decrease in MAP (−34 ± 11 and −83 ± 5 mmHg, respectively) and a pronounced increase in HR ranging from 32 to 49 b.p.m. above baseline. A 10 min infusion of SFGC at doses of 12.5 and 31.2 mg/kg produced a dose-dependent decrease in MAP (−28 ± 18 and −67 ± 12 mmHg below baseline) and a marked increase in HR (26 ± 11 and 94 ± 15 b.p.m. above baseline). 4. In conclusion, unlike iron sucrose and SFGC, high doses of ABT-870 failed to exert consistent hypotensive effects. These data demonstrate that ABT-870 may have a substantial therapeutic window and considerable clinical potential for iron-replacement therapy. [ABSTRACT FROM AUTHOR]