A Study to Evaluate the Safety and Efficacy of Paricalcitol Capsules in Reducing Serum Intact Parathyroid Hormone Levels in End Stage Renal Disease Subjects on Peritoneal Dialysis

Inclusion Criteria: * Subject is greater than or equal to 18 years. * Subject is diagnosed with ESRD and must be on continuous PD 7 days per week for at least 2 months prior to Screening Phase. * If female, subject is either not of childbearing potential or is of childbearing potential and practicing one of the recommended methods of birth control. * If female, subject must have a negative serum pregnancy test prior to treatment. * If female, subject is not breastfeeding. * Subject is undergoing full PD regimen and is expected to remain on this PD regimen for the duration of the study. * For those subjects who have been taking a phosphate binder prior to therapy, the subject has been on a stable type of phosphate binder at least 4 weeks prior to the Pre-Treatment Phase. * For entry into the Pretreatment Phase the subject must have: Calcium level less than or equal to 10.5 mg/dL and Ca x P level less than or equal to 65. * For entry into the Treatment Phase the subject must have: iPTH greater than or equal to 300 pg/mL, calcium level of 8.0 to 10.5 mg/dL, inclusive, and Ca x P less than or equal to 65. * Subject has voluntarily signed and dated an IRB approved informed consent. Exclusion Criteria: * Subject has history of an allergic reaction or significant sensitivity to drugs similar to the study drug * Subject has had active peritonitis within 1 month prior to screening phase. * Subject has had more than one episode of peritonitis within 4 months prior to screening phase. * Subject has received a partial parathyroidectomy within 1 year prior to screening phase. * Subject has had acute renal failure within 3 months of screening phase. * Subject has chronic gastrointestinal disease. * Subject has taken aluminum-containing phosphate binders for greater than 3 weeks in the last 3 months prior to the screening phase or will require these medications greater than 3 weeks in the study. * Subject has a current malignancy or clinically significant liver disease. * Subject has a history of drug or alcohol abuse within 6 months prior to screening phase. * Subject has evidence of poor compliance with diet, medication, or PD. * Subject has participated in any investigational drug or device study within 4 weeks prior to the treatment phase. * Subject is taking maintenance calcitonin, glucocorticoids, or other drugs that may affect calcium or bone metabolism, other than females on stable estrogen and/or progestin therapy. * For any reason, subject is considered by the investigator to be an unsuitable candidate to receive paricalcitol capsules. * Subject is known to be HIV positive.