69794-0102-XX Crysvita 10 MG/ML SOLN (ULTRAGENYX PHARMACEUTICAL)
69794-0203-XX Crysvita 20 MG/ML SOLN (ULTRAGENYX PHARMACEUTICAL)
69794-0304-XX Crysvita 30 MG/ML SOLN (ULTRAGENYX PHARMACEUTICAL)
Burosumab-twza is a human immunoglobulin G subclass 1 (IgG1), anti-human fibroblast growth factor 23 (FGF23) antibody produced by recombinant DNA technology using Chinese hamster ovary cells. It was developed to treat a rare disease, X-linked hypophosphatemia (XLH). XLH is a rare, inherited form of rickets which causes low levels of phosphorus in the blood leading to impaired bone growth and development in children and adolescents as well as lifelong bone mineralization problems.
XLH differs from other forms of rickets in that standard vitamin D therapy is not effective treatment. XLH is caused by excess fibroblast growth factor 23 (FGF23) which suppresses renal tubular phosphate reabsorption and the renal production of 1,25 dihydroxy vitamin D. Burosumab-twza binds to and inhibits the biological activity of FGF23 restoring renal phosphate reabsorption and increasing the serum concentration of 1,25 dihydroxy vitamin D.
Burosumab-twza for the treatment of X-linked hypophosphatemia (XLH) is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
Burosumab-twza for the treatment of other conditions/diseases is considered investigational.
Burosumab-twza is considered medically appropriate if ALL following criteria are met:
Individual is 1 year of age or older
Diagnosis of X-linked hypophosphatemia (XLH) confirmed by ANY ONE of the following:
Serum fibroblast growth factor-23 (FGF23) level > 30 pg/mL
Molecular genetic testing of PHEX-gene (phosphate-regulating endopeptidase homolog, x-linked) pathogenic variant
Documentation of ALL of the following:
Reduced tubular resorption of phosphate corrected for glomerular filtration rate (TmP/GFR)
Baseline fasting serum phosphorus* level with current hypophosphatemia, defined as a phosphate level below the lower limit of the laboratory normal reference range
Individual does not have severe renal impairment, defined as a glomerular filtration rate (GFR) of <30 mL/minor, or end stage renal disease
Individual has not received oral phosphate and active vitamin D analogs within 1 week of starting therapy
* Note: Phosphorous levels should be obtained fasting for 12 hours or more without food or drink except for water and after an adequate washout period after supplements; lab values (i.e. GFR, phosphorous, TmP/GFR) should be obtained within 28 days of the date of administration.
Burosumab-twza is considered medically appropriate for renewal if ALL of the following criteria are met:
Individual continues to meet the initial approval criteria
Absence of unacceptable toxicity from the drug, e.g., severe hypersensitivity reactions, hyperphosphatemia and/or nephrocalcinosis, severe injection site reactions, etc.
Current serum phosphorus level is not above the upper limit of the laboratory normal reference range
Disease response as indicated by increased serum phosphorus levels, a reduction in serum total alkaline phosphatase activity, improvement in symptoms (e.g., skeletal pain, linear growth, etc.), and/or improvement in radiographic imaging of Rickets/osteomalacia
|DOSAGE & ADMINISTRATION|
X-linked hypophosphatemia (XLH)
Pediatric - Starting dose regimen is 0.8 mg/kg of body weight rounded to the nearest 10 mg, administered every two weeks. The minimum starting dose is 10 mg up to a maximum dose of 90 mg.
Measure fasting serum phosphorus every 4 weeks for the first 3 months of treatment, and thereafter as appropriate. If serum phosphorus is above the lower limit of the reference range for age and below 5 mg/dL, continue treatment with the same dose.
Adult - Dose regimen is 1 mg/kg body weight rounded to the nearest 10 mg up to a maximum dose of 90 mg administered every four weeks.
Assess fasting serum phosphorus on a monthly basis, measured 2 weeks post-dose, for the first 3 months of treatment, and thereafter as appropriate. If serum phosphorus is within the normal range, continue with the same dose.
Do not adjust Crysvita more frequently than every 4 weeks.
Crysvita must be administered via subcutaneous injection by a healthcare provider.
LENGTH OF AUTHORIZATION
Coverage will be provided for six months and may be renewed may be renewed every 12 months thereafter
Refer to DOSAGE LIMITS below
APPLICABLE TENNESSEE STATE MANDATE REQUIREMENTS
BlueCross BlueShield of Tennessee’s Medical Policy complies with Tennessee Code Annotated Section 56-7-2352 regarding coverage of off-label indications of Food and Drug Administration (FDA) approved drugs when the off-label use is recognized in one of the statutorily recognized standard reference compendia or in the published peer-reviewed medical literature.
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
For appropriate chemotherapy regimens, dosage information, contraindications, precautions, warnings, and monitoring information, please refer to one of the standard reference compendia (e.g., the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) published by the National Comprehensive Cancer Network®, Drugdex Evaluations of Micromedex Solutions at Truven Health, or The American Hospital Formulary Service Drug Information).
Carpenter, T. O., Whyte, M. P., Imel, E. A., Boot, A. M., Högler, W., Linglart, A., et al. (2018, May). Burosumab therapy in children with X-linked hypophosphatemia. The New England Journal of Medicine, 378 (21), 1987-1998.
Lexicomp Online. (2019). AHFS DI. Burosumab-twza. Retrieved February 20, 2019 from Lexicomp Online with AHFS.
MICROMEDEX Healthcare Series. Drugdex Evaluations. (2019, January). Fluocinolone. Retrieved February 20, 2019 from MICROMEDEX Healthcare Series.
Ruppe, M. D. (2012, February updated 2017, April). X-Linked Hypophosphatemia. In: Adam, M. P., Ardinger, H. H., Pagon, R.A., et al., eds., GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2018. Retrieved April 20, 2018 from www.ncbi.nlm.nih.gov/books/NBK83985/.
U. S. Food and Drug Administration. (2018, April). Center for Drug Evaluation and Research. Crysvita® (burosumab-twza) injection, for subcutaneous use. Retrieved February 20, 2019 from https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/761068s000lbl.pdf.
ORIGINAL EFFECTIVE DATE: 5/25/2018
MOST RECENT REVIEW DATE: 6/30/2019
Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
This document has been classified as public information.
Maximum billable units per dose and over time by indication as a Medical Benefit; 1 billable unit = 1 mg