Long-term treatment of secondary hyperparathyroidism with the calcimimetic cinacalcet HCl.
BACKGROUND
Patients with secondary hyperparathyroidism often require therapy that provides long-term control of parathyroid hormone concentrations without increasing calcium and phosphorus concentrations. Cinacalcet modulates the calcium-sensing receptor on the parathyroid gland to reduce secretion of parathyroid hormone and lower serum calcium, phosphorus and calcium-phosphorus product in haemodialysis patients.


METHODS
Dialysis patients with secondary hyperparathyroidism [parathyroid hormone (PTH) level > or =300 pg/ml] who were enrolled in one of four phase 2 placebo-controlled studies were eligible to enroll in an open-label extension study in which all patients received cinacalcet. For this extension study, cinacalcet was initiated at 30 mg in all patients and the dose was escalated to a maximum of 180 mg once daily if PTH concentrations were >250 pg/ml. Use of concomitant vitamin D sterols and phosphate binders was not restricted.


RESULTS
The analysis of all patients (n = 59) completing 100 weeks of cinacalcet treatment showed long-term control of PTH and calcium-phosphorus product. Approximately 55% achieved a PTH concentration < or =300 pg/ml at the week-100 study visit, and approximately 60% had at least a 30% reduction in PTH from baseline. Serum calcium, phosphorus and the calcium-phosphorus product did not increase during the study. Concomitant vitamin D sterol and phosphate binder therapy remained stable. Cinacalcet was safe and generally well tolerated at doses up to 180 mg/day.


CONCLUSIONS
In this long-term study, cinacalcet effectively sustained reductions in PTH for up to 3 years without increasing concentrations of serum calcium, phosphorus or calcium-phosphorus product.
Moe
Sharon M
SM
Indiana University Department of Medicine, 1001 West 10th Street, OPW 526, Indianapolis, IN 46202, USA. smoe@iupui.edu
Cunningham
John
J
Bommer
Jürgen
J
Adler
Stephen
S
Rosansky
Steven J
SJ
Urena-Torres
Pablo
P
Albizem
Moetaz B
MB
Guo
Matthew D
MD
Zani
Valter J
VJ
Goodman
William G
WG
Sprague
Stuart M
SM
D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D000069449:Cinacalcet; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000150:complications; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000009:adverse effects / Q000627:therapeutic use*; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D044169:Receptors, Calcium-Sensing / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
D009281:Naphthalenes; D010281:Parathyroid Hormone; D044169:Receptors, Calcium-Sensing; D010758:Phosphorus; D002118:Calcium; D000069449:Cinacalcet