Bone Biopsy Study For Dialysis Patients With Secondary Hyperparathyroidism of End Stage Renal Disease

Bone Histomorphometry Assessment For Dialysis Patients With Secondary Hyperparathyroidism of End Stage Renal Disease

The purpose of this study is to evaluate the effects of cinacalcet on markers of bone turnover in patients with kidney disease who are receiving dialysis.

Secondary hyperparathyroidism (HPT) is common in people with end stage renal disease (kidney disease). Patients with secondary HPT often have enlarged parathyroid glands in the neck and as a result often have elevated parathyroid hormone (PTH) levels . Patients with secondary HPT may have bone disease (osteodystrophy). Cinacalcet has been used to decrease PTH levels in patients with secondary HPT. Patients with secondary HPT may have bone disease (osteodystrophy). This bone disease may cause bone pain, fractures, and poor formation of red blood cells. The purpose of this study is to evaluate effects of cinacalcet on markers of bone turnover in patients with kidney disease who are receiving dialysis.

Inclusion Criteria: Subjects will be eligible for the study if they meet all of the following criteria:

• One Intact Parathyroid Hormone (iPTH) determination obtained from the central laboratory must be >/= 300 pg/mL.
• One serum calcium determination obtained from the central laboratory must be >/= 8.4 mg/dL (2.1 mmol/L).
• One Bone Alkaline Phosphatase (BALP) determination obtained from the central laboratory must be >/= 20.9 ng/mL.
• Positive histologic confirmation of high bone turnover disease as assessed by the central bone histology center.
• Treated with dialysis >/= 1 month before the date of informed consent.

Exclusion Criteria: Subjects will be ineligible for the study if they:

• Have an unstable medical condition in the judgment of the investigator.
• Are pregnant or nursing women.
• Had a parathyroidectomy in the 3 months before the date of informed consent.
• For subjects prescribed vitamin D, have received vitamin D therapy for less than 30 days before day 1 or required a change in vitamin D brand or dose level within 30 days before day 1.
• Ever received therapy with Sensipar®/Mimpara®