• Age of 28 days or older and less than 18 years

• Dry weight ≥ 7 kg during screening.

• Diagnosed with CKD and SHPT undergoing hemodialysis at the time of screening.

• Diagnosis of SHPT with the mean of the 2 consecutive central laboratory iPTH values ≥ 400 pg/mL (42 pmol/L) during screening, on separate days and within 2 weeks of enrolment.

• Serum cCa value ≥ 9.0 mg/dL (2.25 mmol/L) for subjects ≥ 2 years of age and older and serum cCa value ≥ 9.6 mg/dL (2.4 mmol/L) for subjects 28 days to \< 2 years of age obtained from the central laboratory during screening.

• Dialysate Ca level ≥ 2.5 mEq/L during screening for at least 4 weeks prior to screening and throughout the duration of the study.

• No more than a maximum prescribed dose change of 50% for active vitamin D sterols/phosphate binders/Ca supplements within the 2 weeks prior to screening assessments and remain stable.

• SHPT not due to vitamin D deficiency, per investigator assessment.