CurrentEmblemHealthPolicy MG.MM.PH.304

Medical Policy: Mepsevii (vestronidase alfa-vjbk) intravenous infusion

Defines medical necessity criteria, dosing limits, authorization length, renewal criteria, applicable procedure/NDC/ICD-10 codes for Mepsevii (vestronidase alfa-vjbk) intravenous infusion for treatment of Mucopolysaccharidosis type VII (MPS VII, Sly syndrome).

Policy Summary

PayerEmblemHealth

PolicyMedical Policy: Mepsevii (vestronidase alfa-vjbk) intravenous infusion

Policy CodePolicy MG.MM.PH.304

Change TypeMaterial revisions and additions

Effective DateMar 17, 2025

Next Review Date

Key ActionTreating physician must submit clinical evidence that the member meets the policy criteria for preauthorization or post-payment review; without documentation EmblemHealth will not be able to properly review the request.

SourceLink

POLICY UPDATE CHANGES

Initial Criteria: replaced prior wording with 'biallelic pathogenic or likely pathogenic glucuronidase (GUS) gene variants' and added minimum age requirement of 5 months and requirement for documented baseline age-appropriate values.

Renewal criteria were added specifying continuation of initial criteria, demonstration of benefit versus baseline, and absence of unacceptable toxicity.

Dosing limits specified as 4 mg/kg IV no more frequently than once every 2 weeks (460 mg every 14 days).

Procedure, NDC, and ICD-10 codes specified: J3397, NDC 69794-0001-01, ICD-10 E76.29.

1Indication covered (MPS VII)

4 mg/kgMaximum dose per administration

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460 mgBillable units per dose

14 daysMinimum dosing interval

Coverage Summary

Coverage stance: covered with criteria for Mepsevii (vestronidase alfa-vjbk) intravenous infusion for the treatment of Mucopolysaccharidosis type VII (MPS VII, Sly syndrome). Indication: recombinant human beta-glucuronidase for MPS VII. Scope summary: defines medical necessity criteria including diagnostic confirmation, specialist prescribing, baseline assessments, dosing limits, and renewal requirements. Dosing limits: Each dose must not exceed 4 mg/kg IV no more frequently than once every 2 weeks (460 billable units [460 mg] every 14 days). Minimum age: >= 5 months.

Initial Therapy Criteria

Initial Criteria

Approve if the patient meets ALL of the following:

ALL of the following

ONE of
- Patient has a laboratory test demonstrating deficient beta-glucuronidase activity in leukocytes, fibroblasts, or serum.
- Patient has a molecular genetic test demonstrating biallelic pathogenic or likely pathogenic glucuronidase (GUS) gene variants.
Patient is at least 5 months of age.>= 5 months
Therapy is being used to treat non-central nervous system manifestations of the disease and patient does not have severe, irreversible cognitive impairment.
Documented baseline age-appropriate values for one or more of the following have been obtained: 6-minute walk test (6-MWT); motor function (e.g., Bruininks-Oseretsky Test of Motor Proficiency [BOT-2]); liver and/or spleen volume; urinary excretion of glycosaminoglycans (GAGs) such as chondroitin sulfate and dermatan sulfate; skeletal involvement (e.g., Z-score); pulmonary function tests; shoulder flexion; visual acuity.
Mepsevii is prescribed by or in consultation with a geneticist, endocrinologist, a metabolic disorder specialist, or a physician who specializes in the treatment of lysosomal storage disorders.

Continuation / Renewal Criteria

Renewal Criteria

Coverage may be renewed when ALL of the following are met:

ALL of the following

Patient continues to meet Initial Criteria.
Patient has demonstrated a beneficial response to therapy compared to pretreatment age-appropriate baseline values in one or more of the following: stability or improvement in 6-MWT, shoulder flexion, pulmonary function tests, visual acuity, and/or motor functions (e.g., BOT-2); reduction in liver and/or spleen volume; reduction in urinary excretion of GAGs; stability or improvement in skeletal disease (e.g., Z-score).
Absence of unacceptable toxicity from the drug (examples of unacceptable toxicity include: anaphylaxis and severe allergic reactions).

Provider Actions & Billing

Prior Authorization

Preauthorization and clinical documentation

Treating physician must submit clinical evidence that the member meets the policy criteria for preauthorization or post-payment review. Without this documentation, EmblemHealth will not be able to properly review the request.

Documentation Required

Baseline assessments required

Obtain and document baseline age-appropriate values for one or more of the following measures prior to initiating therapy: 6-minute walk test (6-MWT); motor function assessment (e.g., Bruininks-Oseretsky Test of Motor Proficiency [BOT-2]); liver and/or spleen volume; urinary excretion of glycosaminoglycans (GAGs) such as chondroitin sulfate and dermatan sulfate; skeletal involvement (e.g., Z-score); pulmonary function tests; shoulder flexion; and visual acuity.

6-minute walk test (6-MWT)
Motor function (e.g., BOT-2)
Liver and/or spleen volume

Applicable Codes

Covered HCPCS/J-codeHCPCSCovered

J3397

Injection, vestronidase alfa-vjbk, 1 mg

Applicable NDCsNDC

69794-0001-01

Mepsevii 2 mg/mL Solution

Applicable ICD-10 Diagnoses (indication targeted)ICD-10Covered

E76.29

Other mucopolysaccharidoses

Clinical Evidence & Definitions

Evidence: Prescribing information — Mepsevii intravenous infusion prescribing information, Ultragenyx; December 2020.

Definitions: Mepsevii — vestronidase alfa-vjbk, a recombinant human lysosomal beta glucuronidase used to catabolize accumulated glycosaminoglycans in MPS VII. Beneficial response — stability or improvement in clinical or laboratory measures compared to pretreatment age-appropriate baseline values (e.g., 6-MWT, BOT-2, organ volumes, urinary GAGs, skeletal Z-score, pulmonary function, visual acuity).

Background

Background: Mepsevii (vestronidase alfa-vjbk) is recombinant human beta-glucuronidase indicated for treatment of MPS VII (Sly syndrome). The policy requires diagnostic confirmation by enzymatic assay demonstrating deficient beta-glucuronidase activity in leukocytes, fibroblasts, or serum, or by molecular genetic testing showing biallelic pathogenic or likely pathogenic GUS gene variants. Baseline age-appropriate measures (e.g., 6-minute walk test, BOT-2, liver/spleen volume, urinary GAGs, skeletal Z-score, pulmonary function tests, shoulder flexion, visual acuity) must be obtained prior to therapy to allow assessment of treatment response.

Revision History

2025-03-17revisedLatest

Initial Criteria revised: replaced prior genetic wording with 'biallelic pathogenic or likely pathogenic glucuronidase (GUS) gene variants'; added minimum age requirement of 5 months; added requirement for documented baseline age-appropriate values; clarified therapy limited to non-central nervous system manifestations and requirement for specialist prescribing.

2025-03-17addedLatest

Renewal criteria added: continuation of initial criteria, demonstration of beneficial response versus pretreatment baseline in one or more specified measures, and absence of unacceptable toxicity (examples include anaphylaxis and severe allergic reactions).

Policy Summary

PayerEmblemHealth

PolicyMedical Policy: Mepsevii (vestronidase alfa-vjbk) intravenous infusion

Policy CodePolicy MG.MM.PH.304

Change TypeMaterial revisions and additions

Effective DateMar 17, 2025

Next Review Date

SourceLink

On This Page

Urinary GAGs (e.g., chondroitin sulfate, dermatan sulfate)

Skeletal involvement (Z-score)

Pulmonary function tests

Billing Rule

Dosing unit billing

Bill using HCPCS code J3397 (Injection, vestronidase alfa-vjbk, 1 mg) at 1 mg per unit. Dosing limit: each dose must not exceed 4 mg/kg IV and may be given no more frequently than once every 2 weeks — equivalent to 460 billable units (460 mg) every 14 days.

Use J3397 billed at 1 mg per unit
Dose limit: ≤ 4 mg/kg per administration
Minimum dosing interval: every 14 days
Maximum billable units per dosing interval: 460 units (460 mg) every 14 days

Prior Authorization

Specialist prescribing requirement

Mepsevii must be prescribed by or in consultation with a geneticist, endocrinologist, a metabolic disorder specialist, or a physician who specializes in the treatment of lysosomal storage disorders.

Denial Risk

Renewal denial risk for toxicity or lack of benefit

Renewal of therapy may be denied if the patient has experienced unacceptable toxicity from the drug (examples include anaphylaxis and severe allergic reactions) or if the patient has not demonstrated a beneficial response to therapy compared to pretreatment age-appropriate baseline values.

Examples of unacceptable toxicity: anaphylaxis, severe allergic reactions
Lack of demonstrated benefit versus baseline (no stability or improvement in specified measures) may lead to denial

2025-03-17revisedLatest

Dosing limits specified: Each dose must not exceed 4 mg/kg IV no more frequently than once every 2 weeks (460 billable units / 460 mg every 14 days).

2025-03-17clarifiedLatest

Procedure, NDC, and ICD-10 codes specified/clarified: J3397 (Injection, vestronidase alfa-vjbk, 1 mg), NDC 69794-0001-01 (Mepsevii 2 mg/mL Solution), ICD-10 E76.29 (Other mucopolysaccharidoses).