Efficacy and Safety of Paricalcitol on the Treatment of Secondary Hyperparathyroidism in Calcitriol Resistant Dialysis Subjects

Inclusion Criteria:

• Male and female participants > 18 years of age, with chronic kidney disease (CKD)stage V;

• Participants with diagnosis of calcitriol resistance defined as: Episodes ofhypercalcemia and/or hyperphosphatemia (defined as an episode of calcium or phosphorusabove Upper Limit of Normal or documented by medical history stating that thetreatment with calcitriol was discontinued due to hypercalcemia and/orhyperphosphatemia) that precludes treatment continuation and/or persistent PTH above 600pg/mL during the calcitriol therapy;

• PTH value at screening visit between 600 pg/mL and 2,000 pg/mL;

• Stable clinical conditions;

• Participant has voluntarily consented to participate in the study, by signing anddating an informed consent form, approved by an Institutional Review Board (IRB)/Independent Ethics Committee (IEC), after the nature of the study has beenexplained and all his questions about the study have been elucidated. The informedconsent must be signed before any study-specific procedures are performed.

Exclusion Criteria:

• Previous parathyroidectomy;

• Presence of hypercalcemia (corrected Ca > 10.5 mg/dL) and/or hyperphosphatemia (P > 6.0 mg/dL) and/or Ca x P product > 60, at screening visit (corrected Ca calculated by: [4 - participant's serum albumin (g/dL)] x 0.8 + participant's serum Ca value);

• Severe and/or unstable clinical conditions, e.g., congestive heart failure, advancedcancer, advanced HIV disease, severe endocrinopathies, uncompensated diabetesmellitus, life-threatening cardiac arrhythmias, etc;

• Abnormal liver tests (> 1.5 times above upper limit of normal);

• Pregnant or breast-feeding women;

• Evidence of vitamin D toxicity;

• Known hypersensitivity to any study drug components.