Paricalcitol in Treating Patients With Advanced Prostate Cancer and Bone Metastases

Inclusion: * Histologically or cytologically confirmed advanced adenocarcinoma of the prostate \- Radiographically proven bone metastasis from prostate cancer * Androgen refractory disease (including anti-androgen withdrawal) * Secondary hyperparathyroidism, defined as two parathyroid hormone (PTH) values \> 70 pg/mL, 14 days apart * ECOG performance status 0-2 * Leukocytes ≥ 3,000/μL * Absolute neutrophil count ≥ 1,500/μL * Platelets ≥ 100,000/μL * Total bilirubin normal * AST/ALT ≤ 2.5 times upper limit of normal * Creatinine clearance ≥ 60 mL/min * Calcium normal * 25-hydroxyvitamin D (25-OHD) ≥ 20 ng/mL * 1,25(OH)\_2D normal * Patients with serum 25-OHD indicative of vitamin D insufficiency are eligible provided they are treated with ergocalciferol to raise 25-OHD levels to 20 ng/mL prior to paricalcitol therapy * More than 8 weeks since prior bisphosphonates * More than 2 weeks since prior palliative radiotherapy * More than 4 weeks since other prior therapy * No more than one prior taxane-containing chemotherapy regimen for metastatic disease * Multiple lines of prior therapy with hormonal agents allowed * Concurrent corticosteroids allowed provided the dose remains stable during the study period Exclusion: * Underlying metabolic bone disease or vitamin D deficiency * History of hypercalcemia * Concurrent uncontrolled illness or co-morbid condition (including psychiatric illness) that would interfere with study compliance * Concurrent ergocalciferol supplementation * Concurrent chemotherapy or hormonal therapy * Concurrent investigational or commercial agents for the malignancy