Therapeutic Class

Lysosomal Enzyme Replacement Therapy

Description

Aldurazyme® (laronidase) is a recombinant enzyme replacement therapy used to treat Mucopolysaccharidosis Type I (MPS I), a rare inherited lysosomal storage disorder caused by deficiency of α-L-iduronidase. This enzyme deficiency leads to accumulation of glycosaminoglycans (GAGs) in tissues and organs, resulting in progressive multisystem complications. Aldurazyme replaces the missing enzyme, helping reduce GAG accumulation and improve disease manifestations.

Aldurazyme is FDA-approved for adult and pediatric patients with Hurler and Hurler-Scheie forms of MPS I, and for patients with the Scheie form who have moderate to severe symptoms. Its effectiveness in mildly affected Scheie patients has not been established, and it has not been shown to improve central nervous system manifestations of MPS I.

Policy (Criteria)

Initial Authorization Criteria

Coverage of Aldurazyme may be considered medically necessary when all of the following criteria are met:

1. Diagnosis of Hurler or Hurler-Scheie forms of Mucopolysaccharidosis I (MPS I) OR Diagnosis of Scheie form of Mucopolysaccharidosis I (MPS I) with moderate to severe symptoms
2. Submission of medical records (e.g., chart notes, laboratory reports, genetic testing results) confirming diagnosis by ONE of the following:
   • Absence or deficiency of α-L-iduronidase enzyme activity as confirmed by enzyme assay
   • Presence of a pathogenic mutation in the IDUA gene as detected by one of the following:
     • An FDA-authorized test,
     • A test performed by a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory

Authorization Duration

Initial authorization may be approved for up to 12 months.

Reauthorization Criteria

Continued coverage of Aldurazyme may be considered medically necessary when the patient demonstrates a positive clinical response to therapy, evidenced by one or more of the following:

• Improvement in functional capacity
• Improvement in pulmonary function
• Stabilization of disease manifestations
• Slowing of disease progression
• Improvement or stabilization in mobility, endurance, or organ involvement documented in medical records

Authorization Duration

Reauthorization may be approved for up to 12 months.

Dosing and Administration

The FDA-approved recommended dosage is:

• 0.58 mg/kg administered once weekly as an intravenous infusion

Patients should receive appropriate monitoring during administration due to the risk of hypersensitivity reactions, including anaphylaxis. Pretreatment with antihistamines and/or antipyretics may be considered.

References

1. ALDURAZYME® (laronidase) Injection Prescribing Information. Genzyme Corporation. Revised December 2023. FDA-approved labeling. ALDURAZYME (laronidase) prescribing information. Initial approval 2003; updated labeling.
2. Wraith JE, Clarke LA, Beck M, et al. Enzyme replacement therapy for mucopolysaccharidosis I: a randomized, double-blind, placebo-controlled study of recombinant human α-L-iduronidase (laronidase). J Pediatr. 2004;144(5):581-588.Aldurazyme® (laronidase) for MPS I Disease | For US HCPs. Sanofi/Genzyme. Accessed September 2026.
3. Clarke LA. Mucopolysaccharidosis Type I. GeneReviews®. University of Washington, Seattle. Updated periodically.
4. Johns Hopkins Medicine/CVS Caremark Specialty Guideline. 2024. Mechanism of action and disease-state overview.

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each Policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

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