Burosumab

Burosumab (INN, sold under the brand name Crysvita, is a human monoclonal antibody medication for the treatment of X-linked hypophosphatemia and tumor-induced osteomalacia.[5][6][7] Burosumab was approved by the FDA for its intended purpose, in patients aged one year and older, in April 2018.[8] The FDA approval fell under both the breakthrough therapy and orphan drug designations.[8][9] It was approved for use in the European Union in February 2018.[10]

Burosumab

Monoclonal antibody
Type	Whole antibody
Source	Human
Target	FGF 23
Clinical data
Pronunciation	bur OH sue mab
Trade names	Crysvita
Other names	KRN-23, KRN23, burosumab-twza
AHFS/Drugs.com	Monograph
MedlinePlus	a618034
License data	EU EMA: by INN US DailyMed: Burosumab
Pregnancy category	US: N (Not classified yet) [1]
Routes of administration	Subcutaneous
ATC code	M05BX05 (WHO)
Legal status
Legal status	UK: POM (Prescription only) [2] US: ℞-only [3] In general: ℞ (Prescription only)
Pharmacokinetic data
Elimination half-life	16.4 days[4]
Identifiers
CAS Number	1610833-03-8
DrugBank	DB14012
ChemSpider	none
UNII	G9WJT6RD29
KEGG	D10913
Chemical and physical data
Formula	C6388H9904N1700O2006S46
Molar mass	144090.15 g·mol^−1

Medical uses

In the United States, burosumab is indicated for the treatment of adults and children ages one year and older with x-linked hypophosphatemia (XLH), a rare, inherited form of rickets,[8] and for the treatment of people age two and older with tumor-induced osteomalacia (TIO), a rare disease that is characterized by the development of tumors that cause weakened and softened bones.[11] The tumors associated with TIO release a peptide hormone-like substance known as fibroblast growth factor 23 (FGF23) that lowers phosphate levels.[11]

In the European Union, burosumab is indicated for the treatment of X-linked hypophosphataemia with radiographic evidence of bone disease in children one year of age and older and adolescents with growing skeletons.[10]

XLH is genetic disorder affecting phosphate metabolism within the body, which results in hypophosphatemia. The disease is characterized by overproduction of the FGF23 hormone in bone cells. The FGF23 hormone is responsible for blocking phosphate re-absorption by the kidney and the suppression of the vitamin D dependent phosphate absorption by the intestine. Due to the excess activity of FGF23, phosphate levels in the blood are abnormally low, which affects the constitution of bone.[12] Thus, burosumab is designed to bind to the FGF23 receptor and inhibit the excess activity of the FGF23 hormone within the body.

While burosumab is effective for the treatment of X-linked hypophosphatemia, the National Institute for Health and Care Excellence in England and Wales initially raised concerns regarding the incremental cost-effectiveness of the new treatment[13] but the drug is available through a simple discount scheme.[14]

History

This drug was developed by Ultragenyx and is in a collaborative license agreement with Kyowa Hakko Kirin.[15]

References

1. "Burosumab (Crysvita) Use During Pregnancy". Drugs.com. 4 May 2018. Retrieved 28 February 2020.
2. "Crysvita 10 mg solution for injection - Summary of Product Characteristics (SmPC)". (emc). 20 April 2020. Retrieved 19 June 2020.
3. "Drug Approval Package: Crysvita (burosumab-twza)". U.S. Food and Drug Administration (FDA). 15 May 2018. Retrieved 28 February 2020.
4. Zhang X, Imel EA, Ruppe MD, Weber TJ, Klausner MA, Ito T, et al. (February 2016). "Pharmacokinetics and pharmacodynamics of a human monoclonal anti-FGF23 antibody (KRN23) in the first multiple ascending-dose trial treating adults with X-linked hypophosphatemia". Journal of Clinical Pharmacology. 56 (2): 176–85. doi:10.1002/jcph.570. PMC 5042055. PMID 26073451.
5. Statement On A Nonproprietary Name Adopted By The USAN Council - Burosumab, American Medical Association.
6. World Health Organization (2016). "International Nonproprietary Names for Pharmaceutical Substances (INN). Proposed INN: List 115" (PDF). WHO Drug Information. 30 (2): 255.
7. "Burosumab (KRN23) for X-Linked Hypophosphatemia (XLH)" (PDF). n.d. Archived from the original (PDF) on 18 April 2018. Retrieved 18 April 2018.
8. "FDA approves first therapy for rare inherited form of rickets, x-linked hypophosphatemia" (Press release). U.S. Food and Drug Administration (FDA). 17 April 2018. This article incorporates text from this source, which is in the public domain.
9. "Crysvita Orphan Drug Designation". U.S. Food and Drug Administration (FDA). 24 December 1999. Retrieved 27 February 2020.
10. "Crysvita EPAR". European Medicines Agency (EMA). 17 September 2018. Retrieved 1 March 2020. This article incorporates text from this source, which is in the public domain.
11. "FDA Approves First Therapy for Rare Disease that Causes Low Phosphate Blood Levels, Bone Softening". U.S. Food and Drug Administration (Press release). 18 June 2020. Retrieved 19 June 2020. This article incorporates text from this source, which is in the public domain.
12. "What Is X-Linked Hypophosphatemia?". Ultragenyx Pharmaceutical.
13. "U.K. cost watchdogs turn away rare disease med Crysvita".
14. "1 Recommendations | Burosumab for treating X-linked hypophosphataemia in children and young people | Guidance | NICE". www.nice.org.uk. Retrieved 14 June 2019.
15. "Collaboration with Ultragenyx to Develop and Commercialize KRN23 for X-linked Hypophosphatemia" (Press release). Kyowa Kirin. 4 September 2013. Retrieved 17 April 2018.

External links

• "Burosumab". Drug Information Portal. U.S. National Library of Medicine.