Last Review Date: 02/01/2024

Date of Origin: 12/12/2017

Dates Reviewed: 12/2017, 10/2018, 02/2019, 02/2020, 02/2021, 02/2022, 02/2023, 04/2023, 02/2024

1. Length of Authorization

Coverage will be provided for 12 months and may be renewed.

2. Dosing Limits

A. Quantity Limit (max daily dose) [NDC Unit]:

• Mepsevii 10 mg/5 mL vial: 46 vials per 14 days

B. Max Units (per dose and over time) [HCPCS Unit]:

• 460 billable units (460 mg) every 14 days

3. Initial Approval Criteria ¹

Coverage is provided in the following conditions:

• Patient is at least 5 months of age; AND
• Documented baseline age-appropriate values for one or more of the following have been obtained: 6-minute walk test (6-MWT), motor function [i.e., 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 (i.e. Z-score), pulmonary function tests, shoulder flexion, visual acuity; AND

**NOTE: For very young patients in which FVC or 6-MWT are not suitable for measuring, requests will be reviewed on a case-by case basis.

Universal Criteria ^1,5,6

• Therapy is being used to treat non-central nervous system manifestations of the disease and patient does not have severe, irreversible cognitive impairment; AND

Mucopolysaccharidosis VII (MPS VII; Sly Syndrome) † Ф ^1,2

• Patient has a definitive diagnosis of MPS VII as confirmed by BOTH of the following:
  • Beta-glucuronidase enzyme deficiency in peripheral blood leukocytes; AND
  • Detection of pathogenic mutations in the GUSB gene by molecular genetic testing

† FDA Approved Indication(s); ‡ Compendia Recommended Indication(s); Ф Orphan Drug

4. Renewal Criteria ^1,2

Coverage may be renewed based on the following criteria:

• Patient continues to meet the universal and other indication-specific relevant criteria such as concomitant therapy requirements (not including prerequisite therapy), performance status, etc. identified in section III; AND

• Absence of unacceptable toxicity from the drug. Examples of unacceptable toxicity include: anaphylaxis and severe allergic reactions, etc.; AND
• 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 (i.e., BOT-2)
  • Reduction in liver and/or spleen volume
  • Reduction in urinary excretion of GAGs
  • Stability of skeletal disease (i.e. improvement in Z-score)

5. Dosage/Administration ¹

6. Billing Code/Availability Information

HCPCS Code:

• J3397 - Injection, vestronidase alfa-vjbk, 1 mg: 1 billable unit = 1 mg

NDC:

• Mepsevii 10 mg/5 mL single-dose vial: 69794-0001-xx

7. References

1. Mepsevii [package insert]. Novato, CA; Ultragenyx Pharmaceutical Inc.; December 2020. Accessed January 2024.
2. Montaño AM, Lock-Hock N, Steiner RD, et al. Clinical course of sly syndrome (mucopolysaccharidosis type VII). J Med Genet. 2016 Jun;53(6):403-18.
3. Harmatz P, Whitley CB, Wang RY, et al. A novel, randomized, placebo-controlled, blind-start, single-crossover phase 3 study to assess the efficacy and safety of UX003 (rhGUS) enzyme replacement therapy in patients with MPS VII. Mol Genet Metab. 2017;120:S63.
4. Qi Y, McKeever K, Taylor J, et al. Pharmacokinetic and Pharmacodynamic Modeling to Optimize the Dose of Vestronidase Alfa, an Enzyme Replacement Therapy for Treatment of Patients with Mucopolysaccharidosis Type VII: Results from Three Trials. Clin Pharmacokinet. 2019 May;58(5):673-683. doi: 10.1007/s40262-018-0721-y.
5. Zhou J, Lin J, Leung WT, Wang L. A basic understanding of mucopolysaccharidosis: Incidence, clinical features, diagnosis, and management. Intractable Rare Dis Res. 2020 Feb;9(1):1-9. doi: 10.5582/irdr.2020.01011.
6. Shapiro EG, Eisengart JB. The natural history of neurocognition in MPS disorders: A review. Mol Genet Metab. 2021 May;133(1):8-34. doi: 10.1016/j.ymgme.2021.03.002. Epub 2021 Mar 11. PMID: 33741271.

Appendix 1 – Covered Diagnosis Codes

Appendix 2 – Centers for Medicare and Medicaid Services (CMS)

The preceding information is intended for non-Medicare coverage determinations. Medicare coverage for outpatient (Part B) drugs is outlined in the Medicare Benefit Policy Manual (Pub. 100-2), Chapter 15, §50 Drugs and Biologicals. In addition, National Coverage Determinations (NCDs) and/or Local Coverage Determinations (LCDs) may exist and compliance with these policies is required where applicable. Local Coverage Articles (LCAs) may also exist for claims payment purposes or to clarify benefit eligibility under Part B for drugs which may be self-administered. The following link may be used to search for NCD, LCD, or LCA documents https://www.cms.gov/medicare-coverage-database/search.aspx. Additional indications, including any preceding information, may be applied at the discretion of the health plan.

Medicare Part B Covered Diagnosis Codes (applicable to existing NCD/LCD/LCA): N/A