The safety and efficacy of ferumoxytol therapy in anemic chronic kidney disease patients.

BACKGROUND: Administration of safe and effective iron therapy in patients with chronic kidney disease is a time consuming process. This phase II clinical trial studied ferumoxytol, a semi-synthetic carbohydrate-coated iron oxide administered by rapid intravenous injection to anemic chronic kidney disease patients (predialysis or undergoing peritoneal dialysis). METHODS: Inclusion criteria included hemoglobin < or =12.5 g/dL and transferrin saturation < or =35%. Twenty-one adult patients were randomized to receive ferumoxytol in a regimen of 4 doses of 255 mg iron in 2 weeks or 2 doses of 510 mg iron in 1 to 2 weeks. Ferumoxytol was administered at a rate of up to 30 mg iron/sec. RESULTS: The maximum hemoglobin response following ferumoxytol administration occurred at 6 weeks, increasing from a baseline of 10.4 +/- 1.3 g/dL to 11.4 +/- 1.2 g/dL (P < 0.05). Ferritin increased from a baseline of 232 +/- 216 ng/mL to a maximum of 931 +/- 361 ng/mL at 2 weeks (P < 0.05), while the baseline transferrin saturation increased from 21 +/- 10% to 37 +/- 22% at 1 week (P < 0.05). Seven adverse events in 5 patients during this trial were deemed possibly related to ferumoxytol, none serious. These events included constipation, chills, tingling, a gastrointestinal viral syndrome, delayed pruritic erythematous rash, and transient pain at the injection site. CONCLUSION: Although larger studies are required, this small study demonstrates that ferumoxytol can be safe and effective in increasing iron stores, is associated with an increased hemoglobin response, and is well tolerated at a rapid infusion rate.

First- and second-generation immunometric PTH assays during treatment of hyperparathyroidism with cinacalcet HCl.

BACKGROUND: First-generation immunometric assays for "intact" parathyroid hormone (iPTH) also measure large N-terminally truncated PTH fragments, whereas second-generation assays, such as the "bio-intact" PTH (biPTH) assay, measure only full-length biologically active PTH(1-84). This study compared iPTH and biPTH assays during cinacalcet treatment in subjects with secondary HPT receiving dialysis. METHODS: Four hundred and ten subjects were enrolled in a 26-week randomized, double-blind, placebo-controlled trial of oral cinacalcet (or placebo), 30 to 180 mg once daily, and efficacy was assessed using biPTH and iPTH assays. RESULTS: Compared with control treatment, cinacalcet improved the management of secondary HPT. Both biPTH and iPTH decreased by 38%+/- 3% during weeks 13 to 26 in the cinacalcet group; biPTH increased by 23%+/- 4% and iPTH increased by 9.5%+/- 3% in the control group (P < 0.001). Fifty-six percent of cinacalcet subjects and 10% of control subjects had a > or = 30% reduction in biPTH, and 61% and 11%, respectively, had a > or = 30% reduction in iPTH. Significant correlations between biPTH and iPTH levels were observed throughout the study. Both assays correlated similarly with bone-specific alkaline phosphatase levels. The ratio of biPTH to iPTH was maintained at 56% +/- 1% after treatment in both treatment groups. Increasing serum calcium levels were associated with a decreasing ratio of biPTH to (iPTH-biPTH). CONCLUSION: These data show that PTH can be monitored with either iPTH or biPTH assays during therapy with cinacalcet, and that cinacalcet therapy does not exert a major influence on the ratio between PTH(1-84) and large, N-terminally truncated PTH fragments.

A preference study: calcium acetate tablets versus gelcaps in hemodialysis patients.

End stage renal disease (ESRD) patients are frequently noncompliant with phosphate binder therapy. This noncompliance may lead to uncontrolled hyperphosphatemia, resulting in an increased risk of mortality via the development of serious comorbid conditions. A new gelcap form of calcium acetate has been introduced for control of hyperphosphatemia. This single center, unblinded study compared calcium acetate tablets versus calcium acetate gelcaps with regards to patient preference and ease of swallowing. Twenty-two patients were randomized to receive 1 day of treatment with calcium acetate tablets, followed by 1 day of treatment with calcium acetate gelcaps, or vice versa. Following completion of the treatment period, the patients were given a questionnaire to complete that asked them to compare their experience with both treatments. Twenty patients completed the study. Eighteen patients preferred the gelcap to the tablet in all preference categories. The same 18 patients responded that the gelcap was easier to swallow than the tablet. Because of the evidence documenting the noncompliant behavior of ESRD patients with respect to their binder therapy, efforts made to give the patients a more satisfying alternative can aid in improving compliance.