Identification of Markers for Determining the Efficacy of Vitamin D Receptor Activator Therapy in Stage 3/4 CKD Patients

After baseline information and laboratory tests are obtained, subjects will be randomized to receive either oral paricalcitol at 2 mcg daily for 2 weeks or placebo. After a washout period of 4 weeks, those subjects who received paricalcitol will receive placebo for 2 weeks and those who received placebo will receive paricalcitol for 2 weeks. A simple blood draw will be obtained from the patient on days 0, 1, and 14 of each treatment arm, and they will also be assessed for side effects at the end of each treatment.

The blood obtained during these visits will be analyzed for any changes that may have occurred in the white blood cells (WBC) and/or plasma. These samples will be tested to see if there are any markers in the blood that changed after treatment with vitamin D. The samples collected will be temporarily stored in the research laboratory and subsequently sent to a separate laboratory (Genus Systems Company) in batches for analysis.

Inclusion criteria

• Chronic kidney disease stage 3/4
• PTH: >70 pg/ml
• If on ACEI/ARB, optimized and stable dose

Exclusion criteria

• Failure to provide informed consent
• Prior active vitamin D oral or parenteral treatment, including calcitriol, paricalcitol and doxercalciferol
• Glomerulonephritis requiring active treatment with immunosuppressive therapy
• Serum phosphorus: > 5.2 mg/dL
• Serum calcium (corrected for albumin): > 10.0 mg/dL
• Clinical unstable medical conditions (other than CKD)
• Use of any investigational drug within the past 30 days or 5 half-lives, whichever is longer
• History of malignancy, other than basal cell carcinoma of the skin
• History of hypersensitivity to vitamin D or its analogs
• Pregnant or nursing (lactating) women
• Women of child-bearing potential