CurrentHealth NetPolicy N/A

Clinical Policy: Burosumab-twza (Crysvita)

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

Policy Summary

PayerHealth Net

PolicyClinical Policy: Burosumab-twza (Crysvita)

Policy CodePolicy N/A

Change TypeAnnual reviews with material revisions (2022, 2024, 2025)

Effective DateSep 1, 2018

Next Review Date

Key ActionProvider must submit office chart notes, lab results or other clinical information showing diagnosis, serum FGF23 or PHEX mutation confirmation, serum phosphorus (within 30 days), weight for dose calculation, prior trials of oral phosphate/vitamin D when applicable, and evidence of clinical response for continuation.

POLICY UPDATE CHANGES

3Q 2025 annual review: for XLH, modified to allow diagnostic confirmation of PHEX gene in member or first-degree relative and added requirement for documentation of member's current weight for dose calculation; added step therapy bypass for IL HIM per IL HB 5395.

3Q 2024 annual review: added requirement to Continued Therapy section that Crysvita not be used concomitantly with oral phosphate or vitamin D replacement therapy for all indications.

3Q 2022 annual review: for TIO added requirement for documentation of member's current weight for dose calculation purposes.

Multiple annual reviews (2021-2023) indicated 'no significant changes' and updates to references and template.

2FDA‑approved indications covered

30 daysRequired recency of serum phosphorus

Typical initial approval duration (Commercial/Medicaid/HIM)

12 monthsContinued therapy approval duration (Medicaid/HIM)

Coverage Summary & Scope

Policy covers burosumab-twza (Crysvita) for X-linked hypophosphatemia (XLH) in patients aged ≥ 6 months and for FGF23-related hypophosphatemia in tumor-induced osteomalacia (TIO) in patients aged ≥ 2 years when tumors are not resectable or cannot be localized. Overall coverage stance: covered with criteria per the clinical policy governing medical necessity, dosing, continuation, exclusions, and coding across Commercial, HIM, and Medicaid lines of business.

Quick reference — thresholds & approval durations

Age for XLH≥ 6 months

Age for TIO≥ 2 years

Required recency of serum phosphorusWithin the last 30 days

Typical initial approval duration6 months (Commercial/Medicaid/HIM) — Commercial may be to member renewal date

Continued therapy approval durationMedicaid/HIM: 12 months; Commercial: 6 months or to member renewal date

Initial Therapy Criteria

Initial Approval Criteria - X-linked hypophosphatemia (XLH)

Covered when ALL of the following are met:

ALL of the following

ONE of
- DNA testing confirms the presence of mutations in the PHEX gene in member or first-degree relative
- Elevated serum FGF23 levels
Prescribed by or in consultation with an endocrinologist or metabolic disease specialist
Serum phosphorus criteria

Continuation Therapy Criteria

Continued Therapy - X-linked hypophosphatemia (XLH)

Continued therapy is authorized when the following are met:

ALL of the following

Current therapy status: Member is currently receiving medication via Centene benefit or has previously met initial approval criteria
Biochemical and clinical response
- Biochemical: Increase in serum phosphorus from baseline and/or maintenance within the normal age- and gender-specific range
  Use laboratory-specific reference ranges if available; otherwise see Appendix D
- Clinical:

Unapproved Indications / Not Authorized

Applicable Codes

Drug HCPCS codeHCPCSCovered

J0584

Injection, burosumab-twza, 1 mg

Provider Actions & Authorization Requirements

Prior Authorization

Prior authorization required

Requests for Crysvita require prior authorization. Approval is granted only when the request demonstrates that all applicable initial or continued therapy criteria in the policy are met. Approval durations differ by line of business (for example, Commercial approvals may be for 6 months or to the member's renewal date, Medicaid/HIM typically 6 months for initial requests and 12 months for some continued therapy requests).

Documentation Required

Support approval with clinical documentation

Support approval by submitting clinical documentation demonstrating the diagnosis and treatment history. Required documents include office chart notes, laboratory results confirming serum FGF23 or PHEX mutation, a serum phosphorus result obtained within the last 30 days, the member's current weight for dose calculation, documentation of prior trials of oral phosphate and vitamin D when applicable, and evidence of clinical response for continuation of therapy.

Clinical Evidence & References

Evidence reviewed includes the Crysvita Prescribing Information (Kyowa Kirin, March 2023) and the policy references list (references reviewed April 2025). The prescribing information and cited references were reviewed and updated during annual policy reviews (documentation of reference review and updates noted in policy revision history).

Background

Burosumab-twza (Crysvita) is an FGF23-blocking antibody indicated for treatment of XLH (patients ≥ 6 months) and for FGF23-related hypophosphatemia in TIO when tumors are not resectable or localized (patients ≥ 2 years). Contextual notes: contraindicated with concomitant oral phosphate or active vitamin D analogs; dosing and maximums are age- and weight-based and required weight documentation is specified for dose calculation purposes. The policy includes dosing limits, monitoring requirements (recent serum phosphorus within 30 days), and criteria for initial and continued therapy consistent with the FDA label and policy revisions.

Definitions

FGF23fibroblast growth factor 23

XLHX-linked hypophosphatemia

TIOtumor-induced osteomalacia

Revision History

3Q 2022policy_revision

Added requirement for documentation of member's current weight for dose calculation for TIO (3Q 2022 annual review); references reviewed and updated; P&T Approval Date = 08.22. Marked material change.

3Q 2024policy_revision

For all indications, added requirement to Continued Therapy that Crysvita not be used concomitantly with oral phosphate or vitamin D replacement therapy (3Q 2024 annual review); references reviewed and updated; P&T Approval Date = 08.24. Marked material change.

3Q 2025policy_revisionLatest

Policy Summary

PayerHealth Net

PolicyClinical Policy: Burosumab-twza (Crysvita)

Policy CodePolicy N/A

Change TypeAnnual reviews with material revisions (2022, 2024, 2025)

Effective DateSep 1, 2018

Next Review Date

On This Page

Below reference: Below the reference range for age and gender (use laboratory-specific reference ranges if available; otherwise see Appendix D) and member has not received oral phosphate or vitamin D replacement therapy

Normal but symptomatic on replacement: In the normal range but member remains symptomatic despite currently receiving oral phosphate and/or vitamin D replacement therapy

Concurrent therapy exclusion: Crysvita is not prescribed concurrently with oral phosphate or vitamin D replacement therapy

Contraindication: concomitant use with oral phosphates and active vitamin D analogs

Weight documentation: Documentation of member's current weight for dose calculation purposes

Dose maximums

Pediatric XLH: Age 6 months to 18 years: ≤ 2 mg/kg up to 90 mg every two weeks
Adult XLH: Age ≥ 18 years: ≤ 1 mg/kg up to 90 mg every four weeks

Age requirement: Age at least 6 months

Initial Approval Criteria - Tumor-Induced Osteomalacia (TIO)

Covered when ALL of the following are met:

ALL of the following

Diagnosis of TIO with confirmed elevated serum FGF23 levels
Prescriber: Prescribed by or in consultation with an endocrinologist or metabolic disease specialist
Tumor resectability/localization: Documentation confirms that the causative tumor(s) is/are not amenable to surgical excision or resection or tumor cannot be localized
Prior therapy: Failure of a ≥ 3 consecutive month trial of oral phosphate and vitamin D replacement unless contraindicated or clinically significant adverse effects are experienced
Serum phosphorus criteria
- Below reference: Below the reference range for age and gender (use laboratory-specific reference ranges if available; otherwise see Appendix D) and member has not received oral phosphate or vitamin D replacement therapy
- Normal but symptomatic on replacement: In the normal range but member remains symptomatic despite currently receiving oral phosphate and/or vitamin D replacement therapy (e.g., osteomalacia, muscle weakness, fatigue, bone pain, fractures)
Concurrent therapy exclusion: Crysvita is not prescribed concurrently with oral phosphate or vitamin D replacement therapy
Contraindication: concomitant use with oral phosphates and active vitamin D analogs
Weight documentation: Documentation of member's current weight for dose calculation purposes
Dose maximum: Dose requested does not exceed 2 mg/kg (maximum 180 mg) every two weeks
Age requirement: Age ≥ 2 years

Initial Approval Criteria - Other diagnoses/indications

Other indications must meet one of the following:

ANY of the following

Formulary coverage: Use is addressed by formulary/no coverage policy for the relevant line of business (referenced policies CP.CPA.190, HIM.PA.33, CP.PMN.255)
Non-formulary policy: For non-formulary uses, follow non-formulary policy for the relevant line of business (referenced policies CP.CPA.190, HIM.PA.103, CP.PMN.16)
Off-label uses: If requested use is not listed and above does not apply, refer to off-label use policy for relevant line of business (CP.CPA.09, HIM.PA.154, CP.PMN.53)

A positive clinical response including any of: enhanced height velocity, improvement in skeletal deformities, reduction of fractures, reduction of generalized bone pain

Concurrent therapy exclusion: Crysvita is not prescribed concurrently with oral phosphate or vitamin D replacement therapy

Weight documentation: Documentation of member's current weight for dose calculation purposes

Dose increase limits

Pediatric XLH: Age 6 months to 18 years: ≤ 2 mg/kg up to 90 mg every two weeks
Adult XLH: Age ≥ 18 years: ≤ 1 mg/kg up to 90 mg every four weeks

Continued Therapy - Tumor-Induced Osteomalacia (TIO)

Continued therapy is authorized when the following are met:

ALL of the following

Current therapy status: Member is currently receiving medication via Centene benefit or has previously met initial approval criteria
Biochemical and clinical response
- Biochemical: Increase in serum phosphorus from baseline and/or maintenance within the normal age- and gender-specific range
  Use laboratory-specific reference ranges if available; otherwise see Appendix D
- Clinical: Documentation confirms improvement in symptoms (e.g., osteomalacia, muscle weakness, fatigue, bone pain, fractures)
Concurrent therapy exclusion: Crysvita is not prescribed concurrently with oral phosphate or vitamin D replacement therapy
Weight documentation: Documentation of member's current weight for dose calculation purposes
Dose increase limit: If request is for a dose increase, new dose does not exceed 2 mg/kg (maximum 180 mg) every two weeks

Office chart notes
Lab results: serum FGF23 or PHEX mutation confirmation
Serum phosphorus (within 30 days)
Current weight (for dose calculation)
Documentation of prior trials of oral phosphate and vitamin D when applicable
Evidence of clinical response (e.g., increased serum phosphorus, symptom improvement)

Billing Rule

Dose calculation and maximums

Dose must be calculated using the member's documented current weight. Dosing must not exceed the mg/kg and absolute maximums specified by indication and age: for pediatric XLH up to 2 mg/kg (maximum 90 mg) every two weeks; adult XLH up to 1 mg/kg (maximum 90 mg) every four weeks; for TIO up to 2 mg/kg (maximum 180 mg) every two weeks.

Denial Risk

Concurrent therapy contraindication

Claims or authorizations may be denied if Crysvita is prescribed concurrently with oral phosphate or active vitamin D analogs; concomitant use is listed as a contraindication and the policy prohibits concurrent prescription for initial and continued therapy.

Documentation Required

Laboratory timing requirement

A serum phosphorus laboratory result used to determine eligibility must be current within the last 30 days.

For XLH, modified to allow diagnostic confirmation of PHEX gene in member or first-degree relative and added requirement for documentation of member's current weight for dose calculation; added step therapy bypass for IL HIM per IL HB 5395; references reviewed and updated (3Q 2025 annual review); P&T Approval Date = 08.25. Marked material change.

2021-2023 (multiple)policy_revision_log

Multiple annual reviews (3Q 2021, 3Q 2023) recorded as 'no significant changes' with references reviewed and updated (dates and P&T approval dates logged).