Eligible people in B.C. living with X-linked hypophosphatemia (XLH), a rare genetic and chronically debilitating bone disorder, will have help as the provincial government is covering costs for burosumab, or Crysvita, the medication used to treat the disease.

Symptoms typically develop around the ages of one or two and include rickets, delayed walking, bowed legs, bone pain, impaired growth and severe dental issues. Adults with XLH can have symptoms such as bone and joint pain, fractures, severe dental issues, hearing loss and fatigue.

The annual cost of burosumab at list price ranges from $130,000 to $1.17 million, depending on the patient’s weight and age. B.C. participated in pan-Canadian Pharmaceutical Alliance negotiations with the manufacturer to finalize its funding decision.

The Ministry of Health will provide funding for burosumab through the BC Expensive Drugs for Rare Diseases (EDRD) process for eligible XLH patients. EDRDs are considered non-benefits, but some drugs and patients may be eligible for coverage on a case-by-case, last-resort basis. Patients will need to discuss their eligibility with their health-care provider.

Prior to the approval of burosumab in Canada, there had been no approved treatments for XLH that target the underlying cause of the disease.

Treatment usually starts at the time of diagnosis and continues until bones stop growing, and includes phosphate supplements combined with high-dose calcitriol. Growth hormones may also be required, as well as orthopedic surgery.

Clinical trials of burosumab in patients under the age of 18 showed reduced deformities in lower extremities, as well as significant improvements in stiffness and the severity of rickets.

There are approximately 15 people with XLH under the age of 18 in B.C.