Safety and Efficacy of Zemplar Capsule in Reducing Serum IPTH Levels in Chronic Kidney Disease Subjects (Three Times Weekly)

Inclusion Criteria:

• Under care of physician at least 2 months (for CKD)

• Not on active Vitamin D therapy for at least 4 weeks prior

• If female:

• Not of childbearing potential, OR

• Practicing birth control

• Not breastfeeding

• If taking phosphate binders, on a stable regimen at least 4 weeks prior

• For entry into Pretreatment Phase:

• iPTH at least 120 pg/mL

• GFR of 15-60 mL/min and no dialysis expected for at least 6 months

• For entry into Treatment Phase:

• Average of 2 consecutive iPTH values of at least 150 pg/mL, taken at least 1 dayapart (all values not less than 120 pg/mL

• 2 consecutive corrected serum calcium levels between 8.0-10.0 mg/dL

• 2 consecutive serum phosphorus levels of not more than 5.2 mg/mL

Exclusion Criteria:

• History of allergic reaction or sensitivity to similar drugs

• Acute Renal Failure within 12 weeks of study

• Chronic gastrointestinal disease

• Spot urine result demonstrating a urine-calcium-to-urine creatinine ratio of greaterthan 0.2, or a history of renal stones

• Taken aluminum-containing phosphate binders within last 12 weeks, or requires suchmedication for more than 3 weeks during study

• Current malignancy, or clinically significant liver disease

• Active granulomatous disease (TB, sarcoidosis, etc.)

• History of drug or alcohol abuse within 6 mos. prior

• Evidence of poor compliance with diet or medication

• Received any investigational drug or participated in any device trial within 30 daysprior

• Taking maintenance calcitonin, bisphosphonates, or drugs that may affect calcium orbone metabolism (other than females on stable estrogen and/or progestin therapy)

• On glucocorticoids for a period of more than 14 days within the last 6 months

• HIV positive