An observational study in Tumor-induced Osteomalacia (TIO), sponsored by Ultragenyx Pharmaceutical Inc. Active, not recruiting at 6 sites in 2 countries. Per ClinicalTrials.gov, last updated 2026-06-03.
Sponsored by Ultragenyx Pharmaceutical Inc · Observational
The objectives of this observational study are to assess the long-term safety and long-term effectiveness of burosumab in patients with TIO who are being treated with burosumab as prescribed by their physician and to monitor the course of the underlying phosphaturic mesenchymal tumor (PMT) overtime in patients with TIO irrespective of their treatment status.
Enrolled patients may or may not be treated with commercially available burosumab during the TIO DMP at the discretion of their treating physician. Given the observational nature of the TIO DMP, specific treatments or supportive management will not be provided as part of the study.
Ultragenyx Pharmaceutical Inc is the lead sponsor of 63 studies on the registry; 8 are open to participants now.
Of its 13 completed or terminated interventional studies of FDA-regulated products, 11 (85%) have results posted.
Counted across the registry records on this site, refreshed daily.
May include patients who have undergone complete tumor resection and continue to have biochemical/clinical evidence of disease, patients with tumor identified, or patients in whom causative tumor has not been identified and who have been diagnosed with TIO based on biochemical/clinical symptom profile.
Patients may be treated with burosumab, or phosphate and active vitamin D metabolites/analogs, as prescribed by a physician, or may be untreated, at any time during the TIO DMP.
Exclusion Criteria:
Other: No intervention
Other: No intervention
Other: No intervention
Access to any treatment is through authorized commercial use and not as part of this DMP
Long-Term Effectiveness of Burosumab: Change From Baseline in Serum Phosporus Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Serum 1,25(OH)2D Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Serum Alkaline Phosphatase (ALP) Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Serum FGF23 Over Time in Participants Not Undergoing Treatment With Burosumab
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Phosphaturic Mesenchymal Tumor (PMT) Size Over Time as Assessed by Tumor Imaging
Time frame: 10 years
Long-Term Safety of Burosumab: Number of Participants With New PMT Development as Assessed by Tumor Imaging
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Serum iPTH Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Serum Calcium Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Urine Calcium Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline Urinary Calcium/Creatinine Ratio
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Serum Creatinine Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Urine Creatinine Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Change From Baseline in Urine Protein/Creatinine Ratio Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Number of Participants With Nephrocalcinosis Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Number of Participants With Serious Adverse Events (SAEs) and Adverse Events (AEs) and Related AEs
Time frame: 10 years
Long-Term Safety of Burosumab: Number of Participants With Incidence and/or Progression of Spinal Stenosis Over Time
Time frame: 10 years
Long-Term Safety of Burosumab: Number of Participants With Normal and/or Potentially Clinically Significant Pregnancy Outcomes
Includes maternal, neonatal and infant outcomes
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Brief Fatigue Inventory (BFI) Scores in Adult Participants Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue Scores in Pediatric Participants Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Brief Pain Inventory (BPI) Scores in Adult Participants Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in PROMIS Pain Scores in Pediatric Participants Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in PROMIS Physical Function Scores Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change From Baseline in Short Form-36 version 2 (SF-36v2) in Adult Participants Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Change in Short Form-10 (SF-10) for Pediatric Participants Over Time
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Number of Participants With Changes From Baseline in Clinical Findings
Time frame: 10 years
Long-Term Effectiveness of Burosumab: Number of Participants With Changes From Baseline in Resource/Health Utilization
Time frame: 10 years
This study is active, not recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Oncogenic osteomalacia
Ultragenyx Pharmaceutical Inc