CurrentmhnPolicy CP.PHAR.11

Burosumab-twza (Crysvita)

Policy defines medical necessity criteria, dosing, approvals, continuation criteria, exclusions, and coding implications for burosumab-twza (Crysvita) for X-linked hypophosphatemia (XLH) and tumor-induced osteomalacia (TIO) across Commercial, HIM, and Medicaid lines of business.

Policy Summary

Payermhn

PolicyBurosumab-twza (Crysvita)

Policy CodePolicy CP.PHAR.11

Change TypeRevisions to criteria, contraindications, and step therapy

Effective DateSep 1, 2018

Next Review Date

Key ActionProvider must submit documentation (office notes, lab results, etc.) demonstrating member meets all approval criteria, including current weight and recent (within 30 days) serum phosphorus and FGF23/lab confirmations.

SourceLink

POLICY UPDATE CHANGES

For XLH, allowed diagnostic confirmation of PHEX gene in member or first-degree relative and added requirement for documentation of member's current weight for dosing.

Modified verbiage to exclude concurrent use of 'active vitamin D analogs' rather than 'vitamin D replacement therapy'.

Added requirement in 2024 continued therapy that Crysvita not be used concomitantly with oral phosphate or vitamin D replacement therapy.

For TIO, added documentation requirement of member's current weight for dose calculation in 2022.

2FDA-approved indications

6 moTypical initial approval duration

J0584Primary billing code

Coverage Summary

Background: Burosumab-twza (Crysvita) is an FGF23-blocking monoclonal antibody indicated for X-linked hypophosphatemia (XLH) in patients 6 months of age and older and for FGF23-related hypophosphatemia in tumor-induced osteomalacia (TIO) in patients 2 years of age and older. Scope: This policy defines medical necessity criteria, dosing, monitoring, continuation criteria, exclusions, and coding implications for Crysvita across Commercial, HIM, and Medicaid lines of business. Coverage stance: covered_with_criteria. Alignment: Policy dosing, monitoring (serum phosphorus), contraindications, and specialty prescribing/monitoring expectations are aligned with FDA labeling and Centene clinical policy requirements. Effective date: 2018-09-01; Last review: 2025-08-25.

Key Policy Summary

FDA-approved indications2

Typical initial approval duration6 months

Primary billing codeJ0584

Serum phosphorus reference ranges (summary)Use lab-specific age/gender ranges when available; otherwise adult ≥18 years: 2.5–4.5 mg/dL; pediatric age-specific ranges provided in Appendix D

TIO step therapy requirementFailure of ≥3 consecutive months of oral phosphate and vitamin D replacement therapy required unless contraindicated; IL HIM requests bypass this requirement per IL HB 5395 (effective 1/1/2026)

Initial Therapy Criteria — X‑Linked Hypophosphatemia (XLH)

Initial Therapy Criteria — Tumor‑Induced Osteomalacia (TIO)

Continuation Therapy — X‑Linked Hypophosphatemia (XLH)

Continuation Therapy — Tumor‑Induced Osteomalacia (TIO)

Exclusions / Not Authorized Indications

Explicit contraindications and concurrent-therapy exclusions: Crysvita must not be prescribed concurrently with oral phosphate or active vitamin D analogs (examples listed include calcitriol, paricalcitol, doxercalciferol, calcifediol). Initiation of Crysvita is contraindicated when serum phosphorus is within or above the normal range for age. Severe renal impairment or end-stage renal disease (ESRD) is also listed as a contraindication due to abnormal mineral metabolism. These exclusions are reflected in the provider actions, denial risk statements, and initial/continued therapy criteria across the policy.

Other Diagnoses / Off‑Label

Provider Actions & Authorization Instructions

Prior Authorization

Prior authorization required

Requests require prior authorization and must meet the stated initial or continuation criteria. Include specialty consult documentation when applicable (endocrinologist or metabolic disease specialist). Billing code: J0584 (Injection, burosumab-twza, 1 mg).

Include specialty consult notes when applicable (endocrinologist/metabolic disease specialist)
Use HCPCS J0584 for billing (Injection, burosumab-twza, 1 mg)

Documentation Required

Submit supporting documentation

Provider must submit supporting documentation such as office notes and lab results demonstrating member meets all approval criteria. Required documentation includes the member's current weight for dose calculation, a serum phosphorus result obtained within the last 30 days, and confirmation of elevated FGF23 or other lab confirmations as applicable. Include specialty consult notes when applicable.

Applicable Codes

HCPCS / Drug J-codeHCPCS

J0584

Injection, burosumab-twza, 1 mg

Clinical Evidence & References

Evidence references: Crysvita Prescribing Information, Kyowa Kirin, March 2023 is cited as the primary reference. Additional references and clinical guidance are listed in the policy references. The policy states it aligns with FDA labeling for indications, dosing, and monitoring, and incorporates Centene clinical policy requirements for prior authorization, specialty prescribing, weight-based dosing limits, and serum phosphorus monitoring.

Background

Mechanism and indications: Burosumab-twza is an FGF23-blocking monoclonal antibody. Indications include XLH for patients aged ≥6 months and FGF23-related hypophosphatemia in TIO for patients aged ≥2 years. Monitoring: the policy requires recent (within 30 days) serum phosphorus for initiation and continued therapy, and specifies age-based reference ranges and withholding recommendations if phosphorus exceeds age-specific upper limits. Contraindications: concomitant use with oral phosphate or active vitamin D analogs, initiation when serum phosphorus is within/above normal range, and severe renal impairment/ESRD. Specialty prescribing: requests must be prescribed by or in consultation with an endocrinologist or metabolic disease specialist and include documentation (office notes, labs, current weight) per FDA-aligned labeling and Centene requirements.

Definitions

FGF23Fibroblast growth factor 23

XLHX-linked hypophosphatemia

TIOTumor-induced osteomalacia

Revision History

3Q 2022clarified

For TIO, added documentation requirement of member's current weight for dose calculation.

3/11/2025revised

Modified verbiage to exclude concurrent use of 'active vitamin D analogs' rather than 'vitamin D replacement therapy'.

3Q 2024revised

Added requirement in continued therapy that Crysvita not be used concomitantly with oral phosphate or vitamin D replacement therapy.

Policy Summary

Payermhn

PolicyBurosumab-twza (Crysvita)

Policy CodePolicy CP.PHAR.11

Change TypeRevisions to criteria, contraindications, and step therapy

Effective DateSep 1, 2018

Next Review Date

SourceLink

On This Page

Current weight for dosing calculations
Serum phosphorus within the last 30 days
FGF23 level or other laboratory confirmations
Specialty consult notes (endocrinologist or metabolic disease specialist)

Billing Rule

Dose limits

Do not exceed dosing maxima by indication: pediatric XLH — up to 2 mg/kg (maximum 90 mg) every two weeks; adult XLH — 1 mg/kg (maximum 90 mg) every four weeks; TIO — up to 2 mg/kg (maximum 180 mg) every two weeks.

XLH (age 6 months to <18 years): up to 2 mg/kg, maximum 90 mg, every 2 weeks
XLH (age ≥18 years): 1 mg/kg, maximum 90 mg, every 4 weeks
TIO (age ≥2 years): up to 2 mg/kg, maximum 180 mg, every 2 weeks

Step Therapy

Step therapy for TIO

For TIO, require failure of a ≥ 3 consecutive month trial of oral phosphate plus vitamin D replacement therapy prior to authorization of Crysvita unless contraindicated or clinically significant adverse effects occur. Exception: Illinois HIM requests are exempt from this step therapy requirement effective 2026-01-01 per IL HB 5395.

≥ 3 months of oral phosphate and vitamin D replacement therapy trial required unless contraindicated or not tolerated
IL HIM step therapy bypass effective 2026-01-01 (IL HB 5395)

Denial Risk

Concurrent therapy contraindication

Requests will be denied if Crysvita is prescribed concurrently with oral phosphate or active vitamin D analogs. Initiation of Crysvita is contraindicated when serum phosphorus is within or above the normal range for age, and concomitant use with oral phosphates or active vitamin D analogs (e.g., calcitriol, paricalcitol, doxercalciferol, calcifediol) is listed as a contraindication.

Do not authorize concurrent prescribing of oral phosphate and/or active vitamin D analogs with Crysvita
Initiation contraindicated if serum phosphorus is within or above age-specific normal range

3Q 2025revised (material)Latest

For XLH, allowed diagnostic confirmation of PHEX gene in member or first-degree relative and added requirement for documentation of member's current weight for dosing; added step therapy bypass for Illinois HIM per IL HB 5395.