Effectiveness of Paricalcitol in Reducing Parathyroid Hormone Levels in X-linked Hypophosphatemic Rickets


Hyperparathyroidism | Hypophosphatemia, Familial

Trial Phase

Trial Purpose and Description

Trial Purpose

The purpose of this study is to determine the effectiveness of paricalcitol, a form of synthetic vitamin D, in lowering parathyroid hormone (PTH) levels and reducing disease symptoms in children and adults with X-linked hypophosphatemic (XLH) rickets.

Participation Guidelines

9 Years and older

Eligibility Criteria

Inclusion Criteria:

  • Diagnosis of XLH rickets
  • Fasting serum calcium of 10.7 mg/dl or less
  • Fasting PTH greater than 40 nleq/ml and less than 120 nleq/ml in the mid-molecule PTH assay at screening (upper limit of normal is 25 nleq/ml)
  • Willing and able to participate in the trial
  • Taking stable dose of standard therapy for XLH rickets for at least 2 months prior to study entry
  • Concomitant therapy for XLH rickets will not be an exclusion criteria
  • Parent or guardian willing to provide informed consent, if applicable

Exclusion Criteria:

  • Concomitant kidney failure (estimated creatinine clearance less than 60 cc/min or serum creatinine greater than 1.5 mg/dl)
  • Serum 25-OH vitamin D less than 20 ng/ml. Participants meeting this criterion will receive vitamin D3 supplementation for 3 months and then be rescreened.
  • Unable to comply with protocol and appropriate follow-up visits
  • Treatment with agents that may affect skeletal metabolism, such as glucocorticoids and anticonvulsants
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
National Institutes of Health
Yale University
Last Updated:
Study HIC#: