Hectorol is a safe and effective treatment of secondary hyperparathyroidism in hemodialysis patients. Hectorol (doxercalciferol capsules) is indicated for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis and in pre-dialysis patients with Stage 3 or Stage 4 chronic kidney disease. Hectorol (doxercalciferol injection) is indicated for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis.

This protocol will determine clinically appropriate doses of Hectorol (doxercalciferol capsules) when converting subject from Hectorol (doxercalciferol injection.) The study will enroll hemodialysis patients that have been controlled on intravenous Hectorol. the information gained from this study will be a useful guide for physicians in managing CKD Stage 5 patients for whom a change from intravenous to oral vitamin D administration is appropriate.

Inclusion Criteria:

• The subject must be receiving hemodialysis three times per week for a minimum of six months.
• The subject must have been receiving Hectorol Injection for a minimum of 3 months. The subject must have been on a stable dose regimen, three times per week administration for a minimum of four weeks.
• The central laboratory assessment must be within the following ranges: serum iPTH between 150-600 pg/mL, inclusive; corrected calcium < 10.0 mg/dL; phosphorus < 7.0 mg/dL.

Exclusion Criteria:

• In the opinion of the Investigator, the subject currently has poorly controlled diabetes mellitus, poorly controlled hypertension, active vasculitis, HIV infection, or any other clinically significant, unstable medical condition.
• Abnormal liver function as measured by ALT/AST greater than two times the upper limit of normal (ULN).
• The subject currently has malabsorption, severe chronic diarrhea, or ileostomy.
• Any evidence of active malignancy except for basal cell carcinoma of the skin. A history of malignancy is not an exclusion.
• Current use of aluminum or magnesium based binders.