ModifiedmhnPolicy CP.PHAR.374

Vestronidase alfa (Mepsevii) therapy for Mucopolysaccharidosis VII

Defines medical necessity, authorization criteria, dosing limits, and duration of coverage for Mepsevii for patients with Mucopolysaccharidosis VII (Sly syndrome) across commercial, HIM/ICHRA, and Medicaid lines of business.

Policy Summary

Payermhn

PolicyVestronidase alfa (Mepsevii) therapy for Mucopolysaccharidosis VII

Policy CodePolicy CP.PHAR.374

Change TypeAuthorization duration and documentation updates

Effective DateSep 1, 2018

Next Review Date

Key ActionProviders must submit clinical documentation including the member's current weight (kg) to support initial approval and reauthorization.

SourceLink

POLICY UPDATE CHANGES

Updated initial and continued approval durations from 6 months to 12 months.

Added requirement for documentation of member's weight to determine appropriate dosing for initial approval and for reauthorization.

Added HIM/ICHRA as a covered line of business.

Added requirement for documentation of member's weight to determine appropriate dosing for initial approval and for reauthorization.

Updated initial and continued approval durations from 6 months to 12 months.

Added ICHRA line of business.

For continued therapy, added examples of positive treatment response that were already outlined in Appendix D.

12 monthsinitial and continued authorization duration (updated)

6→12 mo

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Coverage Criteria

Other Indications

Other diagnoses/uses:

Other Indications: 1) If the drug has had a label change within the last 6 months not yet reflected in this policy, follow the applicable formulary/no-coverage or non-formulary policies for the relevant line of business (see CP.CPA.190, HIM.PA.33, CP.PMN.255, HIM.PA.103, CP.PMN.16 as applicable); OR 2) If the requested use is not specifically listed under section III (Diagnoses/Indications for which coverage is NOT authorized) and criterion 1 does not apply, refer to the off-label use policy for the relevant line of business (CP.CPA.09, HIM.PA.154, CP.PMN.53).

Refer to policy cross-references

Requests for use of vestronidase alfa for non‑FDA approved indications not addressed in this policy are not authorized unless the provider supplies sufficient documentation of efficacy and safety in accordance with the applicable off‑label use policies: CP.CPA.09 (Commercial), HIM.PA.154 (HIM/ICHRA), or CP.PMN.53 (Medicaid).

Use of vestronidase alfa for off‑label indications that are not specifically covered by this policy may be considered only when the request includes the documentation required by the off‑label policies referenced above; absent that supporting evidence, the therapy is considered not medically necessary for non‑FDA approved uses.

Initial Therapy Criteria

Initial Therapy

Initial approval criteria and dosing

Initial Therapy: Dose and dosing interval per prescribing information: 4 mg/kg IV every 2 weeks (maximum dose 4 mg/kg per administration).4 mg/kg every 2 weeks

Use HCPCS J3397 per mg to calculate units

Continuation / Continued Therapy Criteria

Continued Therapy

Continued therapy criteria include examples of positive treatment response and require documentation as outlined in the policy.

examples_of_response: Examples of positive treatment response that can support reauthorization include improvement in: 6-minute walking distance; breathing difficulties; muscle weakness; vision or hearing problems; hepatomegaly or splenomegaly; reduction in total urinary glycosaminoglycan (uGAG) excretion; stair-climbing capacity (3 Minute Stair Climb Test); and pediatric height/weight growth velocity compared to pretreatment records.

Use these examples to document clinical benefit for continued coverage (refer to Appendix D).

Coding and Quantity Limits

HCPCS CodesHCPCS

J3397

Injection, vestronidase alfa-vjbk, 1 mg

inv-07: Maximum dose

Maximum dose per administration4 mg/kg per dose (IV every 2 weeks)

Dosing intervalEvery 2 weeks

Dose threshold in initial criteriaDose does not exceed 4 mg/kg IV every 2 weeks (required for initial approval)

inv-23: Vestronidase alfa (Mepsevii)

Quantity limit (per dose)4 mg/kg per dose (use HCPCS J3397 per mg to calculate number of units)

Dosing intervalAdministered IV every 2 weeks

Billing code for dosing calculation

Provider Actions / Authorization

Prior Authorization

Prior Authorization Required

Prior authorization required — initial and continued use require documentation that all criteria are met including diagnosis confirmation, specialist involvement, clinical signs, dosing limits, and member weight.

Initial and continued therapy require prior authorization.
Provider must submit clinical documentation (office notes, labs, weight) supporting that member meets all approval criteria.
Dose limit: ≤ 4 mg/kg IV every 2 weeks.

Documentation Required

Required Clinical Documentation and Weight

Provider must submit documentation (such as office chart notes, lab results or other clinical information) supporting that member has met all approval criteria. Documentation of the member's current weight (in kg) is required for initial approval and reauthorization to determine appropriate dosing.

Step Therapy / Reauthorization Evidence

Step	Requirement
1	Continued therapy requires evidence of positive treatment response as exemplified in Appendix D (examples of improvement in individual MPS VII manifestations such as 6-minute walk distance, breathing, muscle strength, vision/hearing, hepatomegaly/splenomegaly, reduction in urinary GAG, stair-climbing capacity, pediatric growth velocity).

Site of Care

Billing Rule

Infusion center administration required for IV dosing

IV infusion of vestronidase alfa is administered per the dosing schedule and should be provided in an infusion center or other appropriate IV infusion setting.

Dose: 4 mg/kg IV every 2 weeks
Use appropriate infusion center setting per site‑of‑care guidance

Definitions

inv-17: Mepsevii / vestronidase alfa

Drug descriptionMepsevii (vestronidase alfa-vjbk) is a recombinant human lysosomal beta glucuronidase enzyme replacement therapy.

IndicationIndicated in pediatric and adult patients for the treatment of Mucopolysaccharidosis VII (MPS VII, Sly syndrome).

Limitation of useEffect on central nervous system manifestations of MPS VII has not been determined.

Background

Mucopolysaccharidosis VII (MPS VII, Sly syndrome) is a lysosomal storage disorder caused by deficiency of the enzyme beta‑glucuronidase. Mepsevii (vestronidase alfa‑vjbk) is a recombinant human lysosomal beta‑glucuronidase enzyme replacement therapy indicated for treatment of pediatric and adult patients with MPS VII. The impact of vestronidase alfa on central nervous system manifestations is unknown.

Policy Summary

Payermhn

PolicyVestronidase alfa (Mepsevii) therapy for Mucopolysaccharidosis VII

Policy CodePolicy CP.PHAR.374

Change TypeAuthorization duration and documentation updates

Effective DateSep 1, 2018

Next Review Date

Key ActionProviders must submit clinical documentation including the member's current weight (kg) to support initial approval and reauthorization.

SourceLink

On This Page

Denial Risk

Off‑Label Use May Trigger Denial

Off-label indications may trigger denial — requests for non‑FDA approved uses not addressed in this policy may be denied unless sufficient supporting documentation is provided per the applicable off‑label use policy.

Refer to off‑label use policies: CP.CPA.09 (Commercial), HIM.PA.154 (ICHRA), CP.PMN.53 (Medicaid) as applicable.
If the drug label recently changed and the use is not yet reflected in this policy, follow formulary/non‑formulary guidance referenced in the policy.

Note

Continued Therapy Response Examples

Continued therapy: Member must be responding positively to therapy. Examples of positive treatment response that may support reauthorization include improvement in individual MPS VII disease manifestations such as increased 6‑minute walk distance, reduced breathing difficulties, decreased muscle weakness, improved vision or hearing, reduction in hepatomegaly or splenomegaly, decreased urinary glycosaminoglycan (uGAG) excretion, improved stair‑climbing capacity (3 Minute Stair Climb Test), or improved height/weight growth velocity compared to pretreatment measures.

Document objective measures and clinician assessment of improvement.
If requesting dose increase, new dose must not exceed 4 mg/kg IV every 2 weeks.