Regulatory Decision Summary for Crysvita

Review decision

The Regulatory Decision Summary explains Health Canada’s decision for the product seeking market authorization. The Regulatory Decision Summary includes the purpose of the submission and the reason for the decision.

Product type:


Medicinal ingredient(s):


Therapeutic area:

Drugs for treatment of bone disease

Type of submission:

Priority- Supplemental New Drug Submission (SNDS)

Control number:

What was the purpose of this submission?


Crysvita (burosumab) is a fibroblast growth factor 23 (FGF23) inhibitor, currently authorized for the treatment of X-linked hypophosphatemia (XLH) in adult and pediatric patients 6 months of age and older.

The purpose of this submission is to expend the indication of Crysvita (burosumab) to include the treatment of FGF23 - related hypophosphatemia in tumor-induced osteomalacia (TIO) associated with tumors that cannot be curatively removed or localized in adult patients.

TIO is a rare disease, typically caused by slow growing phosphaturic mesenchymal tumor (PMTs) that produce FGF23 substance that lower serum phosphorus levels leading to bone weakness and softening, hall mark of osteomalacia. TIO is considered a debilitating disease with patients suffering from bone pain/tenderness, muscle weakness and pathological fractures.


Why was the decision issued?


The authorization of Crysvita in adult patients with TIO was based on:

  • A single-arm open-label phase 2 study involving 14 adults with TIO that cannot be resected or localized.
  • Monthly Crysvita increased the low baseline serum phosphorus to within normal level through Week 24 with 50% of patients achieving a mean serum phosphorus level within the normal level averaged across the midpoint of dose interval through Week 24.
  • Of the 9 patients with evaluable bone biopsies, after 48 weeks of treatment, a decreased in the excessive un-mineralized osteoids and a decrease in the mineralization lag time suggestive of improvement in osteomalacia were observed.
  • The number of bone abnormalities classified as “active fractures and pseudofractures” on bone scans decreased from Week 48 to Week 144.

There is no new safety issue identified in the submitted clinical trials.

The overall benefit/risk profile of Crysvita is evaluated in adult patients with TIO that cannot be localized or removed is considered acceptable.

This submission was filed as a priority review according to the Health Canada’s priority Review Policy.  After careful review all available data, a Notice of Compliance (NOC) is recommended.


Decision issued

Authorized; issued a Notice of Compliance with conditions in accordance with the Food and Drug Regulations