Research & Development
Kyowa Kirin Gains EU Approval for the Self-Administration of Crysvita to Treat X-Linked Hypophosphataemia
20 July 2021 - - Crysvita (burosumab) has been approved for the option of self-administration in the European Union for the treatment of X-linked hypophosphataemia, a rare metabolic bone disease that impacts children and adults, Japan-based specialty pharmaceutical company Kyowa Kirin Co., Ltd. (TSX: 4151) said.

The approval means that some patients or carers may be suitable to administer Crysvita themselves, at the recommendation of the treating physician, in its licensed indication for the treatment of XLH in children and adolescents aged 1 to 17 years with radiographic evidence of bone disease, and in adults.

Crysvita is administered by subcutaneous injection.

Crysvita treatment will still need to be initiated by a physician experienced in the management of patients with metabolic bone diseases.

Subsequently, if the patient is receiving a stable dose, the physician may recommend that administration can be performed by the patient or carer following appropriate training.

The first self-administered dose after drug initiation or dose change will need to be conducted under the supervision of a healthcare professional.

This medicinal product is subject to additional monitoring.

X-linked hypophosphataemia is a rare, genetic disease that causes abnormalities in the bones, muscles, and joints.

XLH is not life-threatening, but its burden is life-long and progressive, and it may reduce a person's quality of life.

People with XLH have a genetic defect on the X-chromosome, which causes an excessive loss of phosphate through the urine and poor absorption from the gut, resulting in chronically low levels of phosphate in the blood.

Phosphate is a key mineral needed for maintaining the body's energy levels, muscle function, and the formation of healthy bones and teeth.

While there is no cure for XLH, therapies aimed at helping to restore phosphate to normal levels within the body may help to improve the symptoms of the disease.

XLH is the most common form of hereditary rickets. It can sometimes appear in individuals with no family history of the disease but is usually passed down from a parent who carries the defective gene.10

Crysvita (burosumab) was created and developed by Kyowa Kirin and is a recombinant fully human monoclonal IgG1 antibody against the phosphaturic hormone fibroblast growth factor 23 (FGF23).

FGF23 is a hormone that reduces serum levels of phosphate by regulating phosphate excretion and active vitamin D production by the kidney.

Phosphate wasting and resulting hypophosphataemia in X-linked hypophosphataemia is caused by excess FGF23.

Crysvita is designed to bind to, and thereby inhibit, the biological activity of FGF23. By blocking excess FGF23 in patients, Crysvita is intended to increase phosphate reabsorption from the kidney and increase the production of active vitamin D, which enhances intestinal absorption of phosphate and calcium.

Crysvita has been available for clinical use since 2018. The first approval came from the European Commission, that granted a conditional marketing authorisation for Crysvita for the treatment of XLH with radiographic evidence of bone disease in children one year of age and older and adolescents with growing skeletons.

In 2020, this authorisation was subsequently expanded to include older adolescents and adults.

Crysvita is approved by the US Food and Drug Administration for patients with XLH aged six months and older and by Health Canada for patients with XLH aged one year and older.

In 2019, Crysvita received approval from Japan's Ministry of Health, Labour and Welfare for the treatment of FGF23-related hypophosphataemic rickets and osteomalacia.

In 2020, Crysvita was reimbursed by National Health Insurance in Japan as a self-injection presentation for the treatment of FGF23-related hypophosphataemic rickets and osteomalacia.

In January 2020, Swissmedic approved Crysvita for the treatment of adults, adolescents and children (one year of age and older) with XLH.

In June 2020, the US Food and Drug Administration approved Crysvita for patients aged two and older with tumour-induced osteomalacia, a rare disease that is characterised by the development of tumours that cause weakened and softened bones.

Kyowa Kirin and Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE: Ultragenyx) have been collaborating in the development and commercialisation of Crysvita globally, based on the collaboration and licence agreement between Kyowa Kirin and Ultragenyx.


Related Headlines